source: trunk/doc/src/qmake-manual.qdoc@ 424

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/*!
    \page qmake-manual.html
    \title qmake Manual
    \startpage {index.html}{Qt Reference Documentation}
    \nextpage qmake Tutorial

    \ingroup buildsystem
    \ingroup qttools
    \keyword qmake

    \c qmake is a tool that helps simplify the build
    process for development project across different platforms.  \c qmake
    automates the generation of Makefiles so that only a few lines of
    information are needed to create each Makefile. \c qmake can be used for
    any software project, whether it is written in Qt or not.

    \c qmake generates a Makefile based on the information in a project
    file.  Project files are created by the developer, and are usually
    simple, but more sophisticated project files can be created for
    complex projects.
    \c qmake contains additional features to support development with Qt,
    automatically including build rules for \l{moc.html}{moc}
    and \l{uic.html}{uic}.
    \c qmake can also generate projects for Microsoft Visual studio
    without requiring the developer to change the project file.

    \section1 Getting Started

    The \l{qmake Tutorial} and guide to \l{qmake Common Projects} provide overviews
    that aim to help new users get started with \c qmake.

    \list
    \o \l{qmake Tutorial}
      \tableofcontents{1 qmake Tutorial}
    \endlist

    \list
    \o \l{qmake Common Projects}
      \tableofcontents{1 qmake Common Projects}
    \endlist

    \section1 Table of Contents

    \list
    \o \l{Using qmake}
      \tableofcontents{1 Using qmake}
    \o \l{qmake Project Files}
      \tableofcontents{1 qmake Project Files}
    \o \l{Running qmake}
      \tableofcontents{1 Running qmake}
    \o \l{qmake Platform Notes}
      \tableofcontents{1 qmake Platform Notes}
    \o \l{qmake Advanced Usage}
      \tableofcontents{1 qmake Advanced Usage}
    \o \l{Using Precompiled Headers}
      \tableofcontents{1 Using Precompiled Headers}
    \o \l{qmake Reference}
      \tableofcontents{1 qmake Reference}
    \o \l{qmake Variable Reference}
      \tableofcontents{1 qmake Variable Reference}
    \o \l{qmake Function Reference}
      \tableofcontents{1 qmake Function Reference}
    \o \l{Configuring qmake's Environment}
      \tableofcontents{1 Configuring qmake's Environment}
    \endlist
*/

/*!
    \page qmake-using.html
    \title Using qmake
    \contentspage {qmake Manual}{Contents}
    \previouspage qmake Manual
    \nextpage qmake Project Files

    \c qmake provides a project-oriented system for managing the build
    process for applications, libraries, and other components. This
    approach gives developers control over the source files used, and
    allows each of the steps in the process to be described concisely,
    typically within a single file. \c qmake expands the information in
    each project file to a Makefile that executes the necessary commands
    for compiling and linking.

    In this document, we provide a basic introduction to project files,
    describe some of the main features of \c qmake, and show how to use
    \c qmake on the command line.

    \section1 Describing a Project

    Projects are described by the contents of project (\c .pro) files.
    The information within these is used by \c qmake to generate a Makefile
    containing all the commands that are needed to build each project.
    Project files typically contain a list of source and header files,
    general configuration information, and any application-specific details,
    such as a list of extra libraries to link against, or a list of extra
    include paths to use.

    Project files can contain a number of different elements, including
    comments, variable declarations, built-in functions, and some simple
    control structures. In most simple projects, it is only necessary
    to declare the source and header files that are used to build the
    project with some basic configuration options.

    Complete examples of project files can be found in the
    \l{qmake Tutorial}.
    An introduction to project files can be found in the
    \l{qmake Project Files} chapter, and a more detailed description is
    available in the \l{qmake Reference}.

    \section1 Building a Project

    For simple projects, you only need to run \c qmake in the top
    level directory of your project. By default, \c qmake generates a
    Makefile that you then use to build the project, and you can then
    run your platform's \c make tool to build the project.

    \c qmake can also be used to generate project files. A full
    description of \c{qmake}'s command line options can be found in the
    \l{Running qmake} chapter of this manual.

    \section1 Using Precompiled Headers

    In large projects, it is possible to take advantage of precompiled
    header files to speed up the build process. This feature is described
    in detail in the \l{Using Precompiled Headers} chapter.
*/

/*!
    \page qmake-project-files.html
    \title qmake Project Files
    \contentspage {qmake Manual}{Contents}
    \previouspage Using qmake
    \nextpage Running qmake

    Project files contain all the information required by \c qmake to build
    your application, library, or plugin. The resources used by your project
    are generally specified using a series of declarations, but support for
    simple programming constructs allow you to describe different build
    processes for different platforms and environments.

    \tableofcontents

    \section1 Project File Elements

    The project file format used by \c qmake can be used to support both
    simple and fairly complex build systems. Simple project files will
    use a straightforward declarative style, defining standard variables
    to indicate the source and header files that are used in the project.
    Complex projects may use the control flow structures to fine-tune the
    build process.

    The following sections describe the different types of elements used
    in project files.

    \section2 Variables

    In a project file, variables are used to hold lists of strings.
    In the simplest projects, these variables inform \c qmake about the
    configuration options to use, or supply filenames and paths to use
    in the build process.

    \c qmake looks for certain variables in each project file, and it
    uses the contents of these to determine what it should write to a
    Makefile. For example, the list of values in the \c HEADERS and
    \c SOURCES variables are used to tell \c qmake about header and
    source files in the same directory as the project file.

    Variables can also be used internally to store temporary lists of values,
    and existing lists of values can be overwritten or extended with new
    values.

    The following lines show how lists of values are assigned to variables:

    \snippet doc/src/snippets/qmake/variables.pro 0

    Note that the first assignment only includes values that are specified on
    the same line as the \c SOURCES variable. The second assignment splits
    the items across lines by using the \c \\ character.

    The list of values in a variable is extended in the following way:

    \snippet doc/src/snippets/qmake/variables.pro 1

    The \c CONFIG variable is another special variable that \c qmake
    uses when generating a Makefile. It is discussed in the section on
    \l{#GeneralConfiguration}{general configuration} later in this chapter.
    In the above line, \c qt is added to the list of existing values
    contained in \c CONFIG.

    The following table lists the variables that \c qmake recognizes, and
    describes what they should contain.

    \table
    \header \o Variable \o Contents
    \row \o CONFIG    \o General project configuration options.
    \row \o DESTDIR   \o The directory in which the executable or binary file will
                      be placed.
    \row \o FORMS     \o A list of .ui files to be processed by \c uic.
    \row \o HEADERS   \o A list of filenames of header (.h) files used when
                      building the project.
    \row \o QT        \o Qt-specific configuration options.
    \row \o RESOURCES \o A list of resource (.rc) files to be included in the
                      final project. See the \l{The Qt Resource System} for
                      more information about these files.
    \row \o SOURCES   \o A list of source code files to be used when building
                      the project.
    \row \o TEMPLATE  \o The template to use for the project. This determines
                      whether the output of the build process will be an
                      application, a library, or a plugin.
    \endtable

    The contents of a variable can be read by prepending the variable name with
    \c $$. This can be used to assign the contents of one variable to another:

    \snippet doc/src/snippets/qmake/dereferencing.pro 0

    The \c $$ operator is used extensively with built-in functions that operate
    on strings and lists of values. These are described in the chapter on
    \l{qmake Advanced Usage}.

    Normally, variables are used to contain whitespace-separated lists
    of values. However, it is sometimes necessary to specify values containing
    spaces. These must be quoted in the following way:

    \snippet doc/src/snippets/qmake/quoting.pro 0

    The quoted text is treated as a single item in the list of values held by
    the variable.

    \section2 Comments

    You can add comments to project files. Comments begin with the \c
    # character and continue to the end of the same line. For example:

    \snippet doc/src/snippets/qmake/comments.pro 0

    To include the \c # character in variable assignments, it is necessary
    to use the contents of the built-in \c LITERAL_HASH variable. See the
    \l{qmake Variable Reference#LITERAL_HASH}{variable reference} for more
    information.

    \section2 Built-in Functions and Control Flow

    \c qmake provides a number of built-in functions to allow the contents
    of variables to be processed. The most commonly used function in simple
    project files is the \c include function which takes a filename as an
    argument. The contents of the given file are included in the project
    file at the place where the \c include function is used.
    The \c include function is most commonly used to include other project
    files:

    \snippet doc/src/snippets/qmake/include.pro 0

    Support for conditional structures is made available via
    \l{qmake Advanced Usage#scopes}{scopes} that behave like \c if
    statements in programming languages:

    \snippet doc/src/snippets/qmake/scopes.pro 0

    The assignments inside the braces are only made if the condition is
    true. In this case, the special \c win32 variable must be set; this
    happens automatically on Windows, but this can also be specified on
    other platforms by running \c qmake with the \c{-win32} command line
    option (see \l{Running qmake} for more information). The opening
    brace must stand on the same line as the condition.

    Simple loops are constructed by iterating over lists of values using
    the built-in \c for function. The following code adds directories
    to the \l{qmake Variable Reference#SUBDIRS}{SUBDIRS} variable, but
    only if they exist:

    \snippet doc/src/snippets/qmake/functions.pro 0

    More complex operations on variables that would usually require loops
    are provided by built-in functions such as \c find, \c unique, and
    \c count. These functions, and many others are provided to manipulate
    strings and paths, support user input, and call external tools. A list
    of the functions available can be found in the
    \l{qmake Advanced Usage} chapter of this manual.

    \section1 Project Templates

    The \c TEMPLATE variable is used to define the type of project that will
    be built. If this is not declared in the project file, \c qmake assumes
    that an application should be built, and will generate an appropriate
    Makefile (or equivalent file) for the purpose.

    The types of project available are listed in the following table with
    information about the files that \c qmake will generate for each of them:

    \table
    \header \o Template      \o Description of \c qmake output
    \row    \o app (default) \o Creates a Makefile to build an application.
    \row    \o lib           \o Creates a Makefile to build a library.
    \row    \o subdirs       \o Creates a Makefile containing rules for the
    subdirectories specified using the \l{qmake Variable Reference#SUBDIRS}{SUBDIRS}
    variable. Each subdirectory must contain its own project file.
    \row    \o vcapp         \o Creates a Visual Studio Project file to build
                             an application.
    \row    \o vclib         \o Creates a Visual Studio Project file to build a library.
    \endtable

    See the \l{qmake Tutorial} for advice on writing project files for
    projects that use the \c app and \c lib templates.

    When the \c subdirs template is used, \c qmake generates a Makefile
    to examine each specified subdirectory, process any project file it finds
    there, and run the platform's \c make tool on the newly-created Makefile.
    The \l{qmake Variable Reference#SUBDIRS}{SUBDIRS} variable is used to
    contain a list of all the subdirectories to be processed.

    \target GeneralConfiguration
    \section1 General Configuration

    The \l{qmake Variable Reference#CONFIG}{CONFIG variable} specifies the
    options and features that the compiler should use and the libraries that
    should be linked against. Anything can be added to the \c CONFIG variable,
    but the options covered below are recognized by \c qmake internally.

    The following options control the compiler flags that are used to build the
    project:

    \table
    \header \o Option   \o Description
    \row    \o release  \o The project is to be built in release mode.
            This is ignored if \c debug is also specified.
    \row    \o debug    \o The project is to be built in debug mode.
    \row    \o debug_and_release \o The project is built in \e both debug and
            release modes.
    \row    \o debug_and_release_target \o The project is built in \e both debug 
    and release modes. TARGET is built into \e both the debug and release directories.
    \row    \o build_all \o If \c debug_and_release is specified, the project is
            built in both debug and release modes by default.
    \row    \o autogen_precompile_source \o Automatically generates a \c .cpp file that includes 
    the precompiled header file specified in the .pro file.
    \row    \o ordered  \o When using the \c subdirs template, this option
            specifies that the directories listed should be processed in the
            order in which they are given.
    \row    \o warn_on  \o The compiler should output as many warnings as possible.
            This is ignored if \c warn_off is specified.
    \row    \o warn_off \o The compiler should output as few warnings as possible.
    \row    \o copy_dir_files \o Enables the install rule to also copy directories, not just files.  
   \endtable

    The \c debug_and_release option is special in that it enables \e both debug and
    release versions of a project to be built. In such a case, the Makefile that
    \c qmake generates includes a rule that builds both versions, and this can be
    invoked in the following way:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 0

    Adding the \c build_all option to the \c CONFIG variable makes this rule
    the default when building the project, and installation targets will be
    created for both debug and release builds.

    Note that each of the options specified in the \c CONFIG variable can also be
    used as a scope condition.
    You can test for the presence of certain configuration options by using the
    built-in \l{qmake Function Reference#CONFIG(config)}{CONFIG()} function.
    For example, the following lines show the function as the condition in a scope
    to test whether only the \c opengl option is in use:

    \snippet doc/src/snippets/qmake/configscopes.pro 4
    \snippet doc/src/snippets/qmake/configscopes.pro 5

    This enables different configurations to be defined for \c release and
    \c debug builds, and is described in more detail in the
    \l{qmake Advanced Usage#Scopes}{Scopes} section of the
    \l{qmake Advanced Usage}{Advanced Usage} chapter of this manual.

    The following options define the type of project to be built. Note that some
    of these options only take effect when used on the relevant platform. On other
    platforms, they have no effect.

    \table
    \header \o Option \o Description
    \row    \o qt     \o The project is a Qt application and should link against the Qt
                      library. You can use the \c QT variable to control any additional
                      Qt modules that are required by your application.
    \row    \o thread \o The project is a multi-threaded application.
    \row    \o x11    \o The project is an X11 application or library.
    \endtable

    When using \l{qmake Variable Reference#TEMPLATE}{application or library project
    templates}, more specialized configuration options can be used to fine tune the
    build process. These are explained in details in the
    \l{qmake-common-projects.html}{Common Projects} chapter of this manual.

    For example, if your application uses the Qt library and you want to
    build it as a multi-threaded application in \c debug mode, your project
    file will contain the following line:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 1

    Note, that you must use "+=", not "=", or \c qmake will not be able to
    use Qt's configuration to determine the settings needed for your project.

    \section1 Declaring Qt Libraries

    If the \c CONFIG variable contains the \c qt value, qmake's support for Qt
    applications is enabled. This makes it possible to fine-tune which of the
    Qt modules are used by your application. This is achieved with the \c QT
    variable which can be used to declare the required extension modules.
    For example, we can enable the XML and network modules in the following way:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 2

    Note that \c QT includes the \c core and \c gui modules by default, so the
    above declaration \e adds the network and XML modules to this default list.
    The following assignment \e omits the default modules, and will lead to
    errors when the application's source code is being compiled:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 3

    If you want to build a project \e without the \c gui module, you need to
    exclude it with the "-=" operator. By default, \c QT contains both
    \c core and \c gui, so the following line will result in a minimal
    Qt project being built:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 4

    The table below shows the options that can be used with the \c QT variable
    and the features that are associated with each of them:

    \table
    \header \o Option                     \o Features
    \row    \o core (included by default) \o QtCore module
    \row    \o gui  (included by default) \o QtGui module
    \row    \o network                    \o QtNetwork module
    \row    \o opengl                     \o QtOpenGL module
    \row    \o sql                        \o QtSql module
    \row    \o svg                        \o QtSvg module
    \row    \o xml                        \o QtXml module
    \row    \o xmlpatterns                \o QtXmlPatterns module
    \row    \o qt3support                 \o Qt3Support module
    \endtable

    Note that adding the \c opengl option to the \c QT variable automatically
    causes the equivalent option to be added to the \c CONFIG variable.
    Therefore, for Qt applications, it is not necessary to add the \c opengl
    option to both \c CONFIG and \c{QT}.

    \section1 Configuration Features

    \c qmake can be set up with extra configuration features that are specified
    in feature (.prf) files. These extra features often provide support for
    custom tools that are used during the build process. To add a feature to
    the build process, append the feature name (the stem of the feature filename)
    to the \c CONFIG variable.

    For example, \c qmake can configure the build process to take advantage
    of external libraries that are supported by
    \l{http://www.freedesktop.org/wiki/Software_2fpkgconfig}{pkg-config},
    such as the D-Bus and ogg libraries, with the following lines:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 5

    More information about features can be found in the
    \l{qmake Advanced Usage#Adding New Configuration Features}
    {Adding New Configuration Features} section of the \l{qmake Advanced Usage}
    chapter.

    \section1 Declaring Other Libraries

    If you are using other libraries in your project in addition to those
    supplied with Qt, you need to specify them in your project file.

    The paths that \c qmake searches for libraries and the specific libraries
    to link against can be added to the list of values in the
    \l{qmake Variable Reference#LIBS}{LIBS} variable. The paths to the libraries
    themselves can be given, or the familiar Unix-style notation for specifying
    libraries and paths can be used if preferred.

    For example, the following lines show how a library can be specified:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 6

    The paths containing header files can also be specified in a similar way
    using the \l{qmake Variable Reference#INCLUDEPATH}{INCLUDEPATH} variable.

    For example, it is possible to add several paths to be searched for header
    files:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 7
*/

/*!
    \page qmake-running.html
    \title Running qmake
    \contentspage {qmake Manual}{Contents}
    \previouspage qmake Project Files
    \nextpage qmake Platform Notes

    The behavior of \c qmake can be customized when it is run by
    specifying various options on the command line. These allow the
    build process to be fine-tuned, provide useful diagnostic
    information, and can be used to specify the target platform for
    your project.

    \tableofcontents

    \target Commands
    \section1 Command-Line Options

    \section2 Syntax

    The syntax used to run \c qmake takes the following simple form:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 8

    \c qmake supports two different modes of operation: In the default mode,
    \c qmake will use the description in a project file to generate a Makefile,
    but it is also possible to use \c qmake to generate project files.
    If you want to explicitly set the mode, you must specify it before all
    other options. The \c mode can be either of the following two values:

    \list
    \o \c -makefile \BR
        \c qmake output will be a Makefile.
    \o \c -project \BR
        \c qmake output will be a project file.
    \endlist

    The following \c options are used to specify both general and mode-specific
    settings. Options that only apply to the Makefile mode are described in the
    \l{#MakefileMode}{Makefile Mode Options} section; options that influence the
    creation of project files are described in the
    \l{#ProjectMode}{Project File Options} section.

    The \c files argument represents a list of one or more project files, separated
    by spaces.

    \section2 Options

    A wide range of options can be specified on the command line to \c qmake in
    order to customize the build process, and to override default settings for
    your platform. The following basic options provide usage information, specify
    where \c qmake writes the output file, and control the level of debugging
    information that will be written to the console:

    \list
    \o \c -help \BR
        \c qmake will go over these features and give some useful help.
    \o \c -o file \BR
        \c qmake output will be directed to \e file. If this option
        is not specified, \c qmake will try to use a suitable file name for its
        output, depending on the mode it is running in.\BR
        If '-' is specified, output is directed to stdout.
    \o \c -d \BR
        \c qmake will output debugging information.
    \endlist

    For projects that need to be built differently on each target platform, with
    many subdirectories, you can run \c qmake with each of the following
    options to set the corresponding platform-specific variable in each
    project file:

    \list
    \o \c -unix \BR
        \c qmake will run in unix mode.  In this mode, Unix file
        naming and path conventions will be used, additionally testing for \c unix
        (as a scope) will succeed. This is the default mode on all Unices.
    \o \c -macx \BR
        \c qmake will run in Mac OS X mode.  In this mode, Unix file
        naming and path conventions will be used, additionally testing for \c macx
        (as a scope) will succeed. This is the default mode on Mac OS X.
    \o \c -win32 \BR
        \c qmake will run in win32 mode.  In this mode, Windows file naming and path
        conventions will be used, additionally testing for \c win32 (as a scope)
        will succeed. This is the default mode on Windows.
    \endlist

    The template used for the project is usually specified by the \c TEMPLATE
    variable in the project file. We can override or modify this by using the
    following options:

    \list
    \o \c -t tmpl \BR
        \c qmake will override any set \c TEMPLATE variables with tmpl, but only
        \e after the .pro file has been processed.
    \o \c -tp prefix \BR
        \c qmake will add the prefix to the \c TEMPLATE variable.
    \endlist

    The level of warning information can be fine-tuned to help you find problems in
    your project file:

    \list
    \o \c -Wall \BR
          \c qmake will report all known warnings.
    \o \c -Wnone \BR
          No warning information will be generated by \c qmake.
    \o \c -Wparser \BR
          \c qmake will only generate parser warnings. This will alert
          you to common pitfalls and potential problems in the parsing of your
          project files.
    \o \c -Wlogic \BR
          \c qmake will warn of common pitfalls and potential problems in your
          project file. For example, \c qmake will report whether a file is placed
          into a list of files multiple times, or if a file cannot be found.
    \endlist

    \target MakefileMode
    \section2 Makefile Mode Options

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 9

    In Makefile mode, \c qmake will generate a Makefile that is used to build the
    project. Additionally, the following options may be used in this mode to
    influence the way the project file is generated:

    \list
    \o \c -after \BR
       \c qmake will process assignments given on the command line after
       the specified files.
    \o \c -nocache \BR
       \c qmake will ignore the .qmake.cache file.
    \o \c -nodepend \BR
       \c qmake will not generate any dependency information.
    \o \c -cache file \BR
       \c qmake will use \e file as the cache file, ignoring any other
       .qmake.cache files found.
    \o \c -spec spec \BR
       \c qmake will use \e spec as a path to platform and compiler information,
       and the value of \c QMAKESPEC will be ignored.
    \endlist

    You may also pass \c qmake assignments on the command line;
    they will be processed before all of the files specified. For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 10

    This will generate a Makefile, from test.pro with Unix pathnames.  However
    many of the specified options aren't necessary as they are the default.
    Therefore, the line can be simplified on Unix to:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 11

    If you are certain you want your variables processed after the
    files specified, then you may pass the \c -after option. When this
    is specified, all assignments on the command line after the \c -after
    option will be postponed until after the specified files are parsed.

    \target ProjectMode
    \section2 Project Mode Options

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 12

    In project mode, \c qmake will generate a project file. Additionally, you
    may supply the following options in this mode:

    \list
    \o \c -r \BR
       \c qmake will look through supplied directories recursively
    \o \c -nopwd \BR
       \c qmake will not look in your current working directory for
       source code and only use the specified \c files
    \endlist

    In this mode, the \c files argument can be a list of files or directories.
    If a directory is specified, it will be included in the \c DEPENDPATH
    variable, and relevant code from there will be included in the generated
    project file. If a file is given, it will be appended to the correct
    variable, depending on its extension; for example, .ui files are added
    to \c FORMS, and .cpp files are added to \c SOURCES.

    You may also pass assignments on the command line in this mode. When doing
    so, these assignments will be placed last in the generated project file.
*/

/*!
    \page qmake-platform-notes.html
    \title qmake Platform Notes
    \contentspage {qmake Manual}{Contents}
    \previouspage Running qmake
    \nextpage qmake Advanced Usage

    Many cross-platform projects can be handled by the \c{qmake}'s basic
    configuration features. On some platforms, it is sometimes useful, or even
    necessary, to take advantage of platform-specific features. \c qmake knows
    about many of these features, and these can be accessed via specific
    variables that only have an effect on the platforms where they are relevant.

    \tableofcontents

    \section1 Mac OS X

    Features specific to this platform include support for creating universal
    binaries, frameworks and bundles.

    \section2 Source and Binary Packages

    The version of \c qmake supplied in source packages is configured slightly
    differently to that supplied in binary packages in that it uses a different
    feature specification. Where the source package typically uses the
    \c macx-g++ specification, the binary package is typically configured to
    use the \c macx-xcode specification.

    Users of each package can override this configuration by invoking \c qmake
    with the \c -spec option (see \l{Running qmake} for more information). This
    makes it possible, for example, to use \c qmake from a binary package to
    create a Makefile in a project directory with the following command line
    invocation:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 13

    \section2 Using Frameworks

    \c qmake is able to automatically generate build rules for linking against
    frameworks in the standard framework directory on Mac OS X, located at
    \c{/Library/Frameworks/}.

    Directories other than the standard framework directory need to be specified
    to the build system, and this is achieved by appending linker options to the
    \l{qmake Variable Reference#QMAKE_LFLAGS}{QMAKE_LFLAGS} variable, as shown
    in the following example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 14

    The framework itself is linked in by appending the \c{-framework} options and
    the name of the framework to the \l{qmake Variable Reference#LIBS}{LIBS}
    variable:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 15

    \section2 Creating Frameworks

    Any given library project can be configured so that the resulting library
    file is placed in a
    \l{http://developer.apple.com/documentation/MacOSX/Conceptual/BPFrameworks/Concepts/WhatAreFrameworks.html}
    {framework}, ready for deployment. To do this, set up the project to use the
    \l{qmake Variable Reference#TEMPLATE}{\c lib template} and add the
    \c lib_bundle option to the
    \l{qmake Variable Reference#CONFIG}{CONFIG} variable:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 16

    The data associated with the library is specified using the
    \l{qmake Variable Reference#QMAKE_BUNDLE_DATA}{QMAKE_BUNDLE_DATA}
    variable. This holds items that will be installed with a library
    bundle, and is often used to specify a collection of header files,
    as in the following example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 17

    Here, the \c FRAMEWORK_HEADERS variable is a user-defined variable that
    is used to define the headers required to use a particular framework.
    Appending it to the \c QMAKE_BUNDLE_DATA variable ensures that the
    information about these headers are added to the collection of
    resources that will be installed with the library bundle. Also, the
    framework's name and version are specified by
    \l{qmake Variable Reference#QMAKE_FRAMEWORK_BUNDLE_NAME}
    {QMAKE_FRAMEWORK_BUNDLE_NAME}
    and \l{qmake Variable Reference#QMAKE_FRAMEWORK_VERSION}
    {QMAKE_FRAMEWORK_VERSION} variables. By default, the values used for
    these are obtained from the \l{qmake Variable Reference#TARGET}{TARGET}
    and \l{qmake Variable Reference#VERSION}{VERSION} variables.

    See \l{Deploying an Application on Mac OS X} for more information about
    deploying applications and libraries.

    \section2 Creating Universal Binaries

    To create a universal binary for your application, you need to be using
    a version of Qt that has been configured with the \c{-universal} option.

    The architectures to be supported in the binary are specified with the
    \l{qmake Variable Reference#CONFIG}{CONFIG} variable. For example, the
    following assignment causes \c qmake to generate build rules to create
    a universal binary for both PowerPC and x86 architectures:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 18

    Additionally, developers using a PowerPC-based platform need to set the
    \l{qmake Variable Reference#QMAKE_MAC_SDK}{QMAKE_MAC_SDK} variable.
    This process is discussed in more detail in the
    \l{Deploying an Application on Mac OS X#Architecture Dependencies}{deployment guide for Mac OS X}.

    \section2 Creating and Moving Xcode Projects

    Developers on Mac OS X can take advantage of \c{qmake}'s support for Xcode
    project files, as described in
    \l{Qt is Mac OS X Native#Development Tools}{Qt is Mac OS X Native},
    by running \c qmake to generate an Xcode project from an existing \c qmake
    project files. For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 19

    Note that, if a project is later moved on the disk, \c qmake must be run
    again to process the project file and create a new Xcode project file.

    \section1 Windows

    Features specific to this platform include support for creating Visual
    Studio project files and handling manifest files when deploying Qt
    applications developed using Visual Studio 2005.

    \section2 Creating Visual Studio Project Files

    Developers using Visual Studio to write Qt applications can use the
    Visual Studio integration facilities provided with the
    \l{Qt Commercial Editions} and do not need to worry about how
    project dependencies are managed.

    However, some developers may need to import an existing \c qmake project
    into Visual Studio. \c qmake is able to take a project file and create a
    Visual Studio project that contains all the necessary information required
    by the development environment. This is achieved by setting the \c qmake
    \l{qmake Variable Reference#TEMPLATE}{project template} to either \c vcapp
    (for application projects) or \c vclib (for library projects).

    This can also be set using a command line option, for example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 20

    It is possible to recursively generate \c{.vcproj} files in subdirectories
    and a \c{.sln} file in the main directory, by typing:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 21


    Each time you update the project file, you need to run \c qmake to generate
    an updated Visual Studio project.

    \section2 Visual Studio 2005 Manifest Files

    When deploying Qt applications built using Visual Studio 2005, it is
    necessary to ensure that the manifest file, created when the application
    was linked, is handled correctly. This is handled automatically for
    projects that generate DLLs.

    Removing manifest embedding for application executables can be done with
    the following assignment to the \l{qmake Variable Reference#CONFIG}
    {CONFIG} variable:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 22

    Also, the manifest embedding for DLLs can be removed with the following
    assignment to the \l{qmake Variable Reference#CONFIG}{CONFIG} variable:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 23

    This is discussed in more detail in the
    \l{Deploying an Application on Windows#Visual Studio 2005 Onwards}
    {deployment guide for Windows}.
*/

/*!
    \page qmake-reference.html
    \title qmake Reference
    \contentspage {qmake Manual}{Contents}
    \previouspage Using Precompiled Headers
    \nextpage qmake Variable Reference

    This reference is a detailed index of all the variables and function
    that are available for use in \c qmake project files.

    \section1 Variable Reference

    The \l{qmake Variable Reference} describes the variables that are
    recognized by \c qmake when configuring the build process for
    projects.

    \section1 Function Reference

    The \l{qmake Function Reference} describes the function that can be
    used to process the contents of variables defined in project files.

    \target FrequentlyUsedVariables
    \section1 Frequently Used Variables

    The following variables are frequently used in project files to describe
    common aspects of the build process. These are fully described in the
    \l{qmake-variable-reference.html}{Variable Reference}.

    \list
    \o \l{qmake Variable Reference#CONFIG}{CONFIG}
    \o \l{qmake Variable Reference#DEF_FILE}{DEF_FILE}
    \o \l{qmake Variable Reference#DEFINES}{DEFINES}
    \o \l{qmake Variable Reference#DESTDIR}{DESTDIR}
    \o \l{qmake Variable Reference#DISTFILES}{DISTFILES}
    \o \l{qmake Variable Reference#DLLDESTDIR}{DLLDESTDIR}
    \o \l{qmake Variable Reference#FORMS}{FORMS}
    \o \l{qmake Variable Reference#FORMS3}{FORMS3}
    \o \l{qmake Variable Reference#GUID}{GUID}
    \o \l{qmake Variable Reference#HEADERS}{HEADERS}
    \o \l{qmake Variable Reference#INCLUDEPATH}{INCLUDEPATH}
    \o \l{qmake Variable Reference#LEXSOURCES}{LEXSOURCES}
    \o \l{qmake Variable Reference#LIBS}{LIBS}
    \o \l{qmake Variable Reference#MOC_DIR}{MOC_DIR}
    \o \l{qmake Variable Reference#OBJECTS_DIR}{OBJECTS_DIR}
    \o \l{qmake Variable Reference#QT}{QT}
    \o \l{qmake Variable Reference#RCC_DIR}{RCC_DIR}
    \o \l{qmake Variable Reference#REQUIRES}{REQUIRES}
    \o \l{qmake Variable Reference#SOURCES}{SOURCES}
    \o \l{qmake Variable Reference#SUBDIRS}{SUBDIRS}
    \o \l{qmake Variable Reference#TARGET}{TARGET}
    \o \l{qmake Variable Reference#TEMPLATE}{TEMPLATE}
    \o \l{qmake Variable Reference#TRANSLATIONS}{TRANSLATIONS}
    \o \l{qmake Variable Reference#UI_DIR}{UI_DIR}
    \o \l{qmake Variable Reference#UI_HEADERS_DIR}{UI_HEADERS_DIR}
    \o \l{qmake Variable Reference#UI_SOURCES_DIR}{UI_SOURCES_DIR}
    \o \l{qmake Variable Reference#VERSION}{VERSION}
    \o \l{qmake Variable Reference#YACCSOURCES}{YACCSOURCES}
    \endlist

    \section1 Environment Variables and Configuration

    The \l{Configuring qmake's Environment} chapter of this manual
    describes the environment variables that \c qmake uses when
    configuring the build process.
*/

/*!
    \page qmake-variable-reference.html
    \title qmake Variable Reference
    \contentspage {qmake Manual}{Contents}
    \previouspage qmake Reference
    \nextpage qmake Function Reference

    \c{qmake}'s fundamental behavior is influenced by variable declarations that
    define the build process of each project. Some of these declare resources,
    such as headers and source files, that are common to each platform; others
    are used to customize the behavior of compilers and linkers on specific
    platforms.

    Platform-specific variables follow the naming pattern of the
    variables which they extend or modify, but include the name of the relevant
    platform in their name. For example, \c QMAKE_LIBS can be used to specify a list
    of libraries that a project needs to link against, and \c QMAKE_LIBS_X11 can be
    used to extend or override this list.

    \tableofcontents{3}

    \target CONFIG
    \section1 CONFIG

    The \c CONFIG variable specifies project configuration and
    compiler options.  The values will be recognized internally by
    \c qmake and have special meaning.  They are as follows.

    These \c CONFIG values control compilation flags:

    \table 95%
    \header \o Option   \o Description
    \row    \o release  \o The project is to be built in release mode.
            This is ignored if \c debug is also specified.
    \row    \o debug    \o The project is to be built in debug mode.
    \row    \o debug_and_release \o The project is built in \e both debug and
            release modes. This can have some unexpected side effects (see
            below for more information).
    \row    \o build_all \o If \c debug_and_release is specified, the project is
            built in both debug and release modes by default.
    \row    \o ordered  \o When using the \c subdirs template, this option
            specifies that the directories listed should be processed in the
            order in which they are given.
    \row    \o precompile_header \o Enables support for the use of
            \l{Using Precompiled Headers}{precompiled headers} in projects.
    \row    \o warn_on  \o The compiler should output as many warnings as possible.
            This is ignored if \c warn_off is specified.
    \row    \o warn_off \o The compiler should output as few warnings as possible.
    \omit
    \row    \o qt_debug \o Specifies that the project should be built against
            debug versions of the Qt libraries specified using the
            \l{#QT}{QT} variable.
    \row    \o qt_release \o Specifies that the project should be built against
            release versions of the Qt libraries specified using the
            \l{#QT}{QT} variable.
    \endomit
    \endtable

    Since the \c debug option overrides the \c release option when both are
    defined in the \c CONFIG variable, it is necessary to use the
    \c debug_and_release option if you want to allow both debug and release
    versions of a project to be built. In such a case, the Makefile that
    \c qmake generates includes a rule that builds both versions, and this can
    be invoked in the following way:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 24

    On Windows (or if Qt is configured with \c{-debug_and_release}, adding the
    \c build_all option to the \c CONFIG variable makes this rule the default
    when building the project, and installation targets will be created for
    both debug and release builds.

    Additionally, adding \c debug_and_release to the \c CONFIG variable will
    cause both \c debug and \c release to be defined in the contents of
    \c CONFIG. When the project file is processed, the
    \l{qmake Advanced Usage#Scopes}{scopes} that test for each value will be
    processed for \e both debug and release modes. The \c{build_pass} variable
    will be set for each of these mode, and you can test for this to perform
    build-specific tasks. For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 25

    As a result, it may be useful to define mode-specific variables, such as
    \l{#QMAKE_LFLAGS_RELEASE}{QMAKE_LFLAGS_RELEASE}, instead of general
    variables, such as \l{#QMAKE_LFLAGS}{QMAKE_LFLAGS}, where possible.

    The following options define the application/library type:

    \table 95%
    \header \o Option \o Description
    \row \o qt \o The target is a Qt application/library and requires the Qt
         library and header files. The proper include and library paths for the
         Qt library will automatically be added to the project. This is defined
         by default, and can be fine-tuned with the \c{\l{#qt}{QT}} variable.
    \row \o thread \o The target is a multi-threaded application or library.  The
        proper defines and compiler flags will automatically be added to
        the project.
    \row \o x11 \o The target is a X11 application or library. The proper
        include paths and libraries will automatically be added to the
        project.
    \row \o windows \o The target is a Win32 window application (app only). The
        proper include paths, compiler flags and libraries will
        automatically be added to the project.
    \row \o console \o The target is a Win32 console application (app only). The
        proper include paths, compiler flags and libraries will
        automatically be added to the
        project.
    \row \o shared \o{1,3} The target is a shared object/DLL. The proper
        include paths, compiler flags and libraries will automatically be
        added to the project.
    \row \o dll \o
    \row \o dylib \o
    \row \o static \o{1,2} The target is a static library (lib only).  The proper
        compiler flags will automatically be added to the project.
    \row \o staticlib \o
    \row \o plugin \o The target is a plugin (lib only). This enables dll as well.
    \row \o designer \o The target is a plugin for \QD.
    \row \o uic3 \o Configures qmake to run uic3 on the content of \c FORMS3 if
         defined; otherwise the contents of \c FORMS will be processed instead.
    \row \o no_lflags_merge \o Ensures that the list of libraries stored in the
         \c LIBS variable is not reduced to a list of unique values before it is used.
    \row \o resources \o Configures qmake to run rcc on the content of \c RESOURCES
         if defined.
    \endtable

    These options are used to set the compiler flags:

    \table 95%
    \header \o Option \o Description
    \row \o 3dnow \o AMD 3DNow! instruction support is enabled.
    \row \o exceptions \o Exception support is enabled.
    \row \o mmx \o Intel MMX instruction support is enabled.
    \row \o rtti \o RTTI support is enabled.
    \row \o stl \o STL support is enabled.
    \row \o sse \o SSE support is enabled.
    \row \o sse2 \o SSE2 support is enabled.
    \endtable

    These options define specific features on Windows only:

    \table 95%
    \header \o Option \o Description
    \row \o flat \o When using the vcapp template this will put all the source
         files into the source group and the header files into the header group
         regardless of what directory they reside in.  Turning this
         option off will group the files within the source/header group depending
         on the directory they reside. This is turned on by default.
    \row \o embed_manifest_dll \o Embeds a manifest file in the DLL created
         as part of a library project.
    \row \o embed_manifest_exe \o Embeds a manifest file in the DLL created
         as part of an application project.
    \row \o incremental \o Used to enable or disable incremental linking in Visual
         C++, depending on whether this feature is enabled or disabled by default.
    \endtable

    See \l{qmake Platform Notes#Visual Studio 2005 Manifest Files}{qmake Platform Notes}
    for more information on the options for embedding manifest files.

    These options only have an effect on Mac OS X:

    \table 95%
    \header \o Option \o Description
    \row \o ppc \o Builds a PowerPC binary.
    \row \o x86 \o Builds an i386 compatible binary.
    \row \o app_bundle \o Puts the executable into a bundle (this is the default).
    \row \o lib_bundle \o Puts the library into a library bundle.
    \endtable

    The build process for bundles is also influenced by
    the contents of the \l{#QMAKE_BUNDLE_DATA}{QMAKE_BUNDLE_DATA} variable.

    These options have an effect on Linux/Unix platforms:

    \table 95%
    \header \o Option \o Description
    \row \o largefile \o Includes support for large files.
    \row \o separate_debug_info \o Puts debugging information for libraries in
    separate files.
    \endtable

    The \c CONFIG variable will also be checked when resolving scopes. You may
    assign anything to this variable.

    For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 26

    \target DEFINES
    \section1 DEFINES

    \c qmake adds the values of this variable as compiler C
    preprocessor macros (-D option).

    For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 27

    \target DEF_FILE
    \section1 DEF_FILE

    \e {This is only used on Windows when using the \c app template}.

    Specifies a \c .def file to be included in the project.

    \target DEPENDPATH
    \section1 DEPENDPATH

    This variable contains the list of all directories to look in to
    resolve dependencies. This will be used when crawling through
    \c included files.

    \target DEPLOYMENT
    \section1 DEPLOYMENT

    \e {This is only used on Windows CE.}

    Specifies which additional files will be deployed. Deployment means the
    transfer of files from the development system to the target device or
    emulator.

    Files can be deployed by either creating a Visual Studio project or using
    the \l {Using QTestLib remotely on Windows CE}{cetest} executable.

    For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 28

    This will upload all PNG images in \c path to the same directory your
    build target will be deployed to.

    The default deployment target path for Windows CE is
    \c{%CSIDL_PROGRAM_FILES%\target}, which usually gets expanded to
    \c{\Program Files\target}.

    It is also possible to specify multiple \c sources to be deployed on
    target \c paths. In addition, different variables can be used for
    deployment to different directories.

    For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 29

    \note All linked Qt libraries will be deployed to the path specified
    by \c{myFiles.path}.

    \target DEPLOYMENT_PLUGIN
    \section1 DEPLOYMENT_PLUGIN

    \e {This is only used on Windows CE.}

    This variable specifies the Qt plugins that will be deployed. All plugins
    available in Qt can be explicitly deployed to the device. See
    \l{Static Plugins}{Static Plugins} for a complete list.

    \note No plugins will be deployed automatically. If the application
    depends on plugins, these plugins have to be specified manually.

    For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 128

    This will upload the jpeg imageformat plugin to the plugins directory
    on the Windows CE device.

    \target DESTDIR
    \section1 DESTDIR

    Specifies where to put the \l{#TARGET}{target} file.

    For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 30

    \target DESTDIR_TARGET
    \section1 DESTDIR_TARGET

    This variable is set internally by \c qmake, which is basically the
    \c DESTDIR variable with the \c TARGET variable appened at the end.
    The value of this variable is typically handled by \c qmake or
    \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \target DLLDESTDIR
    \section1 DLLDESTDIR

    Specifies where to copy the \l{#TARGET}{target} dll.

    \target DISTFILES
    \section1 DISTFILES

    This variable contains a list of files to be included in the dist
    target. This feature is supported by UnixMake specs only.

    For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 31

    \target DSP_TEMPLATE
    \section1 DSP_TEMPLATE

    This variable is set internally by \c qmake, which specifies where the
    dsp template file for basing generated dsp files is stored. The value
    of this variable is typically handled by \c qmake or
    \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \target FORMS
    \section1 FORMS

    This variable specifies the .ui files (see \link
    designer-manual.html Qt Designer \endlink) to be processed through \c uic
    before compiling.  All dependencies, headers and source files required
    to build these .ui files will automatically be added to the project.

    For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 32

    If FORMS3 is defined in your project, then this variable must contain
    forms for uic, and not uic3. If CONFIG contains uic3, and FORMS3 is not
    defined, the this variable must contain only uic3 type forms.

    \target FORMS3
    \section1 FORMS3

    This variable specifies the old style .ui files to be processed
    through \c uic3 before compiling, when \c CONFIG contains uic3.
    All dependencies, headers and source files required to build these
    .ui files will automatically be added to the project.

    For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 33

    \target GUID
    \section1 GUID

    Specifies the GUID that is set inside a \c{.vcproj} file. The GUID is
    usually randomly determined. However, should you require a fixed GUID,
    it can be set using this variable.

    This variable is specific to \c{.vcproj} files only; it is ignored
    otherwise.

    \target HEADERS
    \section1 HEADERS

    Defines the header files for the project.

    \c qmake will generate dependency information (unless \c -nodepend
    is specified on the \l{Running qmake#Commands}{command line})
    for the specified headers. \c qmake will also automatically detect if
    \c moc is required by the classes in these headers, and add the
    appropriate dependencies and files to the project for generating and
    linking the moc files.

    For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 34

    See also \l{#SOURCES}{SOURCES}.

    \target INCLUDEPATH
    \section1 INCLUDEPATH

    This variable specifies the #include directories which should be
    searched when compiling the project. Use ';' or a space as the
    directory separator.

    For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 35

    \target INSTALLS
    \section1 INSTALLS

    This variable contains a list of resources that will be installed when
    \c{make install} or a similar installation procedure is executed. Each
    item in the list is typically defined with attributes that provide
    information about where it will be installed.

    For example, the following \c{target.path} definition describes where the
    build target will be installed, and the \c INSTALLS assignment adds the
    build target to the list of existing resources to be installed:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 36

    \target LEXIMPLS
    \section1 LEXIMPLS

    This variable contains a list of lex implementation files.  The value
    of this variable is typically handled by \c qmake or \l{#QMAKESPEC}{qmake.conf} and rarely
    needs to be modified.

    \target LEXOBJECTS
    \section1 LEXOBJECTS

    This variable contains the names of intermediate lex object
    files.The value of this variable is typically handled by
    \c qmake and rarely needs to be modified.

    \target LEXSOURCES
    \section1 LEXSOURCES

    This variable contains a list of lex source files.  All
    dependencies, headers and source files will automatically be added to
    the project for building these lex files.

    For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 37

    \target LIBS
    \section1 LIBS

    This variable contains a list of libraries to be linked into the project.
    You can use the Unix \c -l (library) and -L (library path) flags and qmake
    will do the correct thing with these libraries on Windows (namely this
    means passing the full path of the library to the linker). The only
    limitation to this is the library must exist, for qmake to find which
    directory a \c -l lib lives in.

    For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 38

    \bold{Note:} On Windows, specifying libraries with the \c{-l} option,
    as in the above example, will cause the library with the highest version
    number to be used; for example, \c{libmath2.lib} could potentially be used
    instead of \c{libmathlib}. To avoid this ambiguity, we recommend that you
    explicitly specify the library to be used by including the \c{.lib}
    file name suffix.

    By default, the list of libraries stored in \c LIBS is reduced to a list of
    unique names before it is used. To change this behavior, add the
    \c no_lflags_merge option to the \c CONFIG variable:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 39

    \target LITERAL_HASH
    \section1 LITERAL_HASH

    This variable is used whenever a literal hash character (\c{#}) is needed in
    a variable declaration, perhaps as part of a file name or in a string passed
    to some external application.

    For example:

    \snippet doc/src/snippets/qmake/comments.pro 1

    By using \c LITERAL_HASH in this way, the \c # character can be used
    to construct a URL for the \c message() function to print to the console.

    \target MAKEFILE
    \section1 MAKEFILE

    This variable specifies the name of the Makefile which
    \c qmake should use when outputting the dependency information
    for building a project.  The value of this variable is typically
    handled by \c qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \target MAKEFILE_GENERATOR
    \section1 MAKEFILE_GENERATOR

    This variable contains the name of the Makefile generator to use
    when generating a Makefile.  The value of this variable is typically
    handled internally by \c qmake and rarely needs to be modified.

    \target MOC_DIR
    \section1 MOC_DIR

    This variable specifies the directory where all intermediate moc
    files should be placed.

    For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 40

    \target OBJECTS
    \section1 OBJECTS

    This variable is generated from the \link #SOURCES SOURCES
    \endlink variable.  The extension of each source file will have been
    replaced by .o (Unix) or .obj (Win32).  The value of this variable is
    typically handled by \c qmake or \l{#QMAKESPEC}{qmake.conf} and
    rarely needs to be modified.

    \target OBJECTS_DIR
    \section1 OBJECTS_DIR

    This variable specifies the directory where all intermediate
    objects should be placed.

    For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 41

    \target OBJMOC
    \section1 OBJMOC

    This variable is set by \c qmake if files can be found that
    contain the Q_OBJECT macro.  \c OBJMOC contains the
    name of all intermediate moc object files. The value of this variable
    is typically handled by \c qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs to be
    modified.

    \target POST_TARGETDEPS
    \section1 POST_TARGETDEPS

    All libraries that the \l{#TARGET}{target} depends on can be
    listed in this variable. Some backends do not support this, these include
    MSVC Dsp, and ProjectBuilder .pbproj files. Generally this is supported
    internally by these build tools, this is useful for explicitly listing
    dependant static libraries.

    This list will go after all builtin (and \link #PRE_TARGETDEPS
    $$PRE_TARGETDEPS \endlink) dependencies.

    \target PRE_TARGETDEPS
    \section1 PRE_TARGETDEPS

    All libraries that the \l{#TARGET}{target} depends on can be
    listed in this variable. Some backends do not support this, these include
    MSVC Dsp, and ProjectBuilder .pbproj files. Generally this is supported
    internally by these build tools, this is useful for explicitly listing
    dependant static libraries.

    This list will go before all builtin dependencies.

    \target PRECOMPILED_HEADER
    \section1 PRECOMPILED_HEADER

    This variable indicates the header file for creating a precompiled
    header file, to increase the compilation speed of a project.
    Precompiled headers are currently only supported on some platforms
    (Windows - all MSVC project types, Mac OS X - Xcode, Makefile,
    Unix - gcc 3.3 and up).

    On other platforms, this variable has different meaning, as noted
    below.

    This variable contains a list of header files that require some
    sort of pre-compilation step (such as with moc). The value of this
    variable is typically handled by \c qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs to be
    modified.

    \target PWD
    \section1 PWD

    This variable contains the full path leading to the directory where
    the \c qmake project file (project.pro) is located.

    \target OUT_PWD
    \section1 OUT_PWD

    This variable contains the full path leading to the directory where
    \c qmake places the generated Makefile.

    \target QMAKE_systemvariable
    \section1 QMAKE

    This variable contains the name of the \c qmake program
    itself and is placed in generated Makefiles.  The value of this
    variable is typically handled by \c qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs to be
    modified.

    \target QMAKESPEC_systemvariable
    \section1 QMAKESPEC

    This variable contains the name of the \c qmake
    configuration to use when generating Makefiles.  The value of this
    variable is typically handled by \c qmake and rarely needs to be modified.

    Use the \c{QMAKESPEC} environment variable to override the \c qmake configuration.
    Note that, due to the way \c qmake reads project files, setting the \c{QMAKESPEC}
    environment variable from within a project file will have no effect.

    \target QMAKE_APP_FLAG
    \section1 QMAKE_APP_FLAG

    This variable is empty unless the \c app
    \l{#TEMPLATE}{TEMPLATE} is specified.  The value of this
    variable is typically handled by \c qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs to be
    modified.  Use the following instead:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 42

    \target QMAKE_APP_OR_DLL
    \section1 QMAKE_APP_OR_DLL

    This variable is empty unless the \c app or \c dll
    \l{#TEMPLATE}{TEMPLATE} is specified.  The value of this
    variable is typically handled by \c qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs to be
    modified.

    \target QMAKE_AR_CMD
    \section1 QMAKE_AR_CMD

    \e {This is used on Unix platforms only.}

    This variable contains the command for invoking the program which
    creates, modifies and extracts archives. The value of this variable is
    typically handled by \c qmake or \l{#QMAKESPEC}{qmake.conf}
    and rarely needs to be modified.

    \target QMAKE_BUNDLE_DATA
    \section1 QMAKE_BUNDLE_DATA

    This variable is used to hold the data that will be installed with a library
    bundle, and is often used to specify a collection of header files.

    For example, the following lines add \c path/to/header_one.h
    and \c path/to/header_two.h to a group containing information about the
    headers supplied with the framework:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 43

    The last line adds the information about the headers to the collection of
    resources that will be installed with the library bundle.

    Library bundles are created when the \c lib_bundle option is added to the
    \l{#CONFIG}{CONFIG} variable.

    See \l{qmake Platform Notes#Creating Frameworks}{qmake Platform Notes} for
    more information about creating library bundles.

    \e{This is used on Mac OS X only.}

    \section1 QMAKE_BUNDLE_EXTENSION

    This variable defines the extension to be used for library bundles.
    This allows frameworks to be created with custom extensions instead of the
    standard \c{.framework} directory name extension.

    For example, the following definition will result in a framework with the
    \c{.myframework} extension:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 44

    \e{This is used on Mac OS X only.}

    \section1 QMAKE_CC

    This variable specifies the C compiler that will be used when building
    projects containing C source code. Only the file name of the compiler
    executable needs to be specified as long as it is on a path contained
    in the \c PATH variable when the Makefile is processed.

    \target QMAKE_CFLAGS_DEBUG
    \section1 QMAKE_CFLAGS_DEBUG

    This variable contains the flags for the C compiler in debug mode.The value of this variable is
    typically handled by \c qmake or \l{#QMAKESPEC}{qmake.conf}
    and rarely needs to be modified.

    \target QMAKE_CFLAGS_MT
    \section1 QMAKE_CFLAGS_MT

    This variable contains the compiler flags for creating a
    multi-threaded application or when the version of Qt that you link
    against is a multi-threaded statically linked library.  The value of
    this variable is typically handled by \c qmake or
    \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \target QMAKE_CFLAGS_MT_DBG
    \section1 QMAKE_CFLAGS_MT_DBG

    This variable contains the compiler flags for creating a debuggable
    multi-threaded application or when the version of Qt that you link
    against is a debuggable multi-threaded statically linked library.  The
    value of this variable is typically handled by \c qmake or
    \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \target QMAKE_CFLAGS_MT_DLL
    \section1 QMAKE_CFLAGS_MT_DLL

    \e {This is used on Windows only.}

    This variable contains the compiler flags for creating a
    multi-threaded dll or when the version of Qt that you link
    against is a multi-threaded dll.  The value of this variable is typically
    handled by \c qmake or \l{#QMAKESPEC}{qmake.conf} and
    rarely needs to be modified.

    \target QMAKE_CFLAGS_MT_DLLDBG
    \section1 QMAKE_CFLAGS_MT_DLLDBG

    \e {This is used on Windows only.}

    This variable contains the compiler flags for creating a debuggable
    multi-threaded dll or when the version of Qt that you link
    against is a debuggable multi-threaded statically linked library.
    The value of this variable is typically handled by \c qmake or
    \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \target QMAKE_CFLAGS_RELEASE
    \section1 QMAKE_CFLAGS_RELEASE

    This variable contains the compiler flags for creating a non-debuggable
    application.  The value of this variable is typically
    handled by \c qmake or \l{#QMAKESPEC}{qmake.conf} and
    rarely needs to be modified.

    \target QMAKE_CFLAGS_SHLIB
    \section1 QMAKE_CFLAGS_SHLIB

    \e {This is used on Unix platforms only.}

    This variable contains the compiler flags for creating a shared
    library. The value of this variable is typically handled by
    \c qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs
    to be modified.

    \target QMAKE_CFLAGS_THREAD
    \section1 QMAKE_CFLAGS_THREAD

    This variable contains the compiler flags for creating a multi-threaded
    application. The value of this variable is typically handled by
    \c qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs
    to be modified.

    \target QMAKE_CFLAGS_WARN_OFF
    \section1 QMAKE_CFLAGS_WARN_OFF

    This variable is not empty if the warn_off
    \l{#TEMPLATE}{TEMPLATE} option is specified.  The value of this
    variable is typically handled by \c qmake or \l{#QMAKESPEC}{qmake.conf}
    and rarely needs to be modified.

    \target QMAKE_CFLAGS_WARN_ON
    \section1 QMAKE_CFLAGS_WARN_ON

    This variable is not empty if the warn_on
    \l{#TEMPLATE}{TEMPLATE} option is specified.
    The value of this variable is typically handled by
    \c qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs
    to be modified.

    \target QMAKE_CLEAN
    \section1 QMAKE_CLEAN

    This variable contains any files which are not generated files (such as moc and uic
    generated files) and object files that should be removed when using "make clean".

    \section1 QMAKE_CXX

    This variable specifies the C++ compiler that will be used when building
    projects containing C++ source code. Only the file name of the compiler
    executable needs to be specified as long as it is on a path contained
    in the \c PATH variable when the Makefile is processed.

    \section1 QMAKE_CXXFLAGS

    This variable contains the C++ compiler flags that are used when building
    a project. The value of this variable is typically handled by \c qmake or
    \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified. The flags
    specific to debug and release modes can be adjusted by modifying
    the \c QMAKE_CXXFLAGS_DEBUG and \c QMAKE_CXXFLAGS_RELEASE variables,
    respectively.

    \target QMAKE_CXXFLAGS_DEBUG
    \section1 QMAKE_CXXFLAGS_DEBUG

    This variable contains the C++ compiler flags for creating a debuggable
    application. The value of this variable is typically handled by
    \c qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs
    to be modified.

    \target QMAKE_CXXFLAGS_MT
    \section1 QMAKE_CXXFLAGS_MT

    This variable contains the C++ compiler flags for creating a multi-threaded
    application. The value of this variable is typically handled by
    \c qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs
    to be modified.

    \target QMAKE_CXXFLAGS_MT_DBG
    \section1 QMAKE_CXXFLAGS_MT_DBG

    This variable contains the C++ compiler flags for creating a debuggable multi-threaded
    application. The value of this variable is typically handled by
    \c qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs
    to be modified.

    \target QMAKE_CXXFLAGS_MT_DLL
    \section1 QMAKE_CXXFLAGS_MT_DLL

    \c {This is used on Windows only.}

    This variable contains the C++ compiler flags for creating a multi-threaded
    dll. The value of this variable is typically handled by
    \c qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs
    to be modified.

    \target QMAKE_CXXFLAGS_MT_DLLDBG
    \section1 QMAKE_CXXFLAGS_MT_DLLDBG

    \c {This is used on Windows only.}

    This variable contains the C++ compiler flags for creating a multi-threaded debuggable
    dll. The value of this variable is typically handled by
    \c qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs
    to be modified.

    \target QMAKE_CXXFLAGS_RELEASE
    \section1 QMAKE_CXXFLAGS_RELEASE

    This variable contains the C++ compiler flags for creating an
    application. The value of this variable is typically handled by
    \c qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs
    to be modified.

    \target QMAKE_CXXFLAGS_SHLIB
    \section1 QMAKE_CXXFLAGS_SHLIB

    This variable contains the C++ compiler flags for creating a
    shared library.  The value of this variable is typically handled by
    \c qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs
    to be modified.

    \target QMAKE_CXXFLAGS_THREAD
    \section1 QMAKE_CXXFLAGS_THREAD

    This variable contains the C++ compiler flags for creating a
    multi-threaded application.  The value of this variable is typically handled by
    \c qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs
    to be modified.

    \target QMAKE_CXXFLAGS_WARN_OFF
    \section1 QMAKE_CXXFLAGS_WARN_OFF

    This variable contains the C++ compiler flags for suppressing compiler warnings.
    The value of this variable is typically handled by \c qmake or
    \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \target QMAKE_CXXFLAGS_WARN_ON
    \section1 QMAKE_CXXFLAGS_WARN_ON

    This variable contains C++ compiler flags for generating compiler warnings.
    The value of this variable is typically handled by \c qmake or
    \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \target QMAKE_DISTCLEAN
    \section1 QMAKE_DISTCLEAN

    This variable removes extra files upon the invocation of \c{make distclean}.

    \target QMAKE_EXTENSION_SHLIB
    \section1 QMAKE_EXTENSION_SHLIB

    This variable contains the extention for shared libraries.  The value of this
    variable is typically handled by \c qmake or \l{#QMAKESPEC}{qmake.conf}
    and rarely needs to be modified.

    Note that platform-specific variables that change the extension will override
    the contents of this variable.

    \section1 QMAKE_EXT_MOC

    This variable changes the extention used on included moc files.

    See also \l{Configuring qmake's Environment#Extensions}{File Extensions}.

    \section1 QMAKE_EXT_UI

    This variable changes the extention used on /e Designer UI files.

    See also \l{Configuring qmake's Environment#Extensions}{File Extensions}.

    \section1 QMAKE_EXT_PRL

    This variable changes the extention used on created PRL files.

    See also \l{Configuring qmake's Environment#Extensions}{File Extensions},
             \l{Configuring qmake's Environment#libdepend}{Library Dependencies}.

    \section1 QMAKE_EXT_LEX

    This variable changes the extention used on files given to lex.

    See also \l{Configuring qmake's Environment#Extensions}{File Extensions},
             \l{#LEXSOURCES}{LEXSOURCES}.

    \section1 QMAKE_EXT_YACC
    This variable changes the extention used on files given to yacc.

    See also \l{Configuring qmake's Environment#Extensions}{File Extensions},
             \l{#YACCSOURCES}{YACCSOURCES}.

    \section1 QMAKE_EXT_OBJ

    This variable changes the extention used on generated object files.

    See also \l{Configuring qmake's Environment#Extensions}{File Extensions}.

    \section1 QMAKE_EXT_CPP

    This variable changes the interpretation of all suffixes in this
    list of values as files of type C++ source code.

    See also \l{Configuring qmake's Environment#Extensions}{File Extensions}.

    \section1 QMAKE_EXT_H

    This variable changes the interpretation of all suffixes in this
    list of values as files of type C header files.

    See also \l{Configuring qmake's Environment#Extensions}{File Extensions}.

        \section1 QMAKE_EXTRA_COMPILERS

        This variable contains the extra compilers/preprocessors that have been added

        See also \l{Configuring qmake's Environment#Customizing}{Customizing Makefile Output}

        \section1 QMAKE_EXTRA_TARGETS

        This variable contains the extra targets that have been added

        See also \l{Configuring qmake's Environment#Customizing}{Customizing Makefile Output}

    \target QMAKE_FAILED_REQUIREMENTS
    \section1 QMAKE_FAILED_REQUIREMENTS

    This variable contains the list of requirements that were failed to be met when
    \c qmake was used.  For example, the sql module is needed and wasn't compiled into Qt.  The
    value of this variable is typically handled by \c qmake or \l{#QMAKESPEC}{qmake.conf}
    and rarely needs to be modified.

    \target QMAKE_FILETAGS
    \section1 QMAKE_FILETAGS

    This variable contains the file tags needed to be entered into the Makefile, such as SOURCES
    and HEADERS.  The value of this variable is typically handled by \c qmake or
    \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_FRAMEWORK_BUNDLE_NAME

    In a framework project, this variable contains the name to be used for the
    framework that is built.

    By default, this variable contains the same value as the \l{#TARGET}{TARGET}
    variable.

    See \l{qmake Platform Notes#Creating Frameworks}{qmake Platform Notes} for
    more information about creating frameworks and library bundles.

    \e{This is used on Mac OS X only.}

    \target QMAKE_FRAMEWORK_VERSION
    \section1 QMAKE_FRAMEWORK_VERSION

    For projects where the build target is a Mac OS X framework, this variable
    is used to specify the version number that will be applied to the framework
    that is built.

    By default, this variable contains the same value as the \l{#VERSION}{VERSION}
    variable.

    See \l{qmake Platform Notes#Creating Frameworks}{qmake Platform Notes} for
    more information about creating frameworks.

    \e{This is used on Mac OS X only.}

    \target QMAKE_INCDIR
    \section1 QMAKE_INCDIR

    This variable contains the location of all known header files to be added to
    INCLUDEPATH when building an application.  The value of this variable is
    typically handled by \c qmake or \l{#QMAKESPEC}{qmake.conf} and rarely
    needs to be modified.

    \target QMAKE_INCDIR_OPENGL
    \section1 QMAKE_INCDIR_OPENGL

    This variable contains the location of OpenGL header files to be added
    to INCLUDEPATH when building an application with OpenGL support. The
    value of this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \target QMAKE_INCDIR_QT
    \section1 QMAKE_INCDIR_QT

    This variable contains the location of all known header file
    paths to be added to INCLUDEPATH when building a Qt application. The value
    of this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \target QMAKE_INCDIR_THREAD
    \section1 QMAKE_INCDIR_THREAD

    This variable contains the location of all known header file
    paths to be added to INCLUDEPATH when building a multi-threaded application.
    The value of this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \target QMAKE_INCDIR_X11
    \section1 QMAKE_INCDIR_X11

    \e {This is used on Unix platforms only.}

    This variable contains the location of X11 header file paths to be
    added to INCLUDEPATH when building a X11 application.  The
    value of this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \target QMAKE_INFO_PLIST
    \section1 QMAKE_INFO_PLIST

    \e {This is used on Mac OS X platforms only.}

    This variable contains the name of the property list file, \c{.plist}, you
    would like to include in your Mac OS X application bundle.

    In the \c{.plist} file, you can define some variables, e.g., @EXECUTABLE@,
    which qmake will replace with the actual executable name. Other variables
    include @ICON@, @TYPEINFO@, @LIBRARY@, and @SHORT_VERSION@.

    \note Most of the time, the default \c{Info.plist} is good enough.

    \section1 QMAKE_LFLAGS

    This variable contains a general set of flags that are passed to
    the linker. If you need to change the flags used for a particular
    platform or type of project, use one of the specialized variables
    for that purpose instead of this variable.

    \target QMAKE_LFLAGS_CONSOLE
    \section1 QMAKE_LFLAGS_CONSOLE

    \e {This is used on Windows only.}

    This variable contains link flags when building console
    programs.  The value of this variable is typically handled by
    \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LFLAGS_CONSOLE_DLL

    \e {This is used on Windows only.}

    This variable contains link flags when building console
    dlls.  The value of this variable is typically handled by
    \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LFLAGS_DEBUG

    This variable contains link flags when building debuggable applications.  The
    value of this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LFLAGS_PLUGIN

    This variable contains link flags when building plugins. The value
    of this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LFLAGS_QT_DLL

    This variable contains link flags when building programs that
    use the Qt library built as a dll. The value of this variable is
    typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LFLAGS_RELEASE

    This variable contains link flags when building applications for
    release. The value of this variable is typically handled by
    \c qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LFLAGS_SHAPP

    This variable contains link flags when building applications which are using
    the \c app template.  The value of this variable is typically handled by
    \c qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LFLAGS_SHLIB

    This variable contains link flags when building shared libraries
    The value of this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LFLAGS_SONAME

    This variable specifies the link flags to set the name of shared objects,
    such as .so or .dll.  The value of this variable is typically handled by \c
    qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LFLAGS_THREAD

    This variable contains link flags when building multi-threaded projects.
    The value of this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LFLAGS_WINDOWS

    \e {This is used on Windows only.}

    This variable contains link flags when building Windows GUI projects
    (i.e. non-console applications).
    The value of this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LFLAGS_WINDOWS_DLL

    \e {This is used on Windows only.}

    This variable contains link flags when building Windows DLL projects.
    The value of this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LIBDIR

    This variable contains the location of all known library
    directories.The value of this variable is typically handled by
    \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LIBDIR_FLAGS

    \e {This is used on Unix platforms only.}

    This variable contains the location of all library
    directory with -L prefixed.  The value of this variable is typically handled by
    \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LIBDIR_OPENGL

    This variable contains the location of the OpenGL library
    directory.The value of this variable is typically handled by
    \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LIBDIR_QT

    This variable contains the location of the Qt library
    directory.The value of this variable is typically handled by
    \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LIBDIR_X11

    \e {This is used on Unix platforms only.}

    This variable contains the location of the X11 library
    directory.The value of this variable is typically handled by
    \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LIBS

    This variable contains all project libraries.  The value of this
    variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LIBS_CONSOLE

    \e {This Windows-specific variable is no longer used.}

    Prior to Qt 4.2, this variable was used to list the libraries
    that should be linked against when building a console application
    project on Windows. \l{#QMAKE_LIBS_WINDOW}{QMAKE_LIBS_WINDOW}
    should now be used instead.

    \section1 QMAKE_LIBS_OPENGL

    This variable contains all OpenGL libraries.  The value of this
    variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LIBS_OPENGL_QT

    This variable contains all OpenGL Qt libraries.The value of this
    variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LIBS_QT

    This variable contains all Qt libraries.The value of this
    variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LIBS_QT_DLL

    \e {This is used on Windows only.}

    This variable contains all Qt libraries when Qt is built as a dll.  The
    value of this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LIBS_QT_OPENGL

    This variable contains all the libraries needed to link against if
    OpenGL support is turned on. The
    value of this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LIBS_QT_THREAD

    This variable contains all the libraries needed to link against if
    thread support is turned on.  The
    value of this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LIBS_RT

    \e {This is used with Borland compilers only.}

    This variable contains the runtime library needed to link against when
    building an application.  The
    value of this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LIBS_RTMT

    \e {This is used with Borland compilers only.}

    This variable contains the runtime library needed to link against when
    building a multi-threaded application.  The
    value of this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LIBS_THREAD

    \e {This is used on Unix platforms only.}

    This variable contains all libraries that need to be linked against
    when building a multi-threaded application.  The
    value of this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LIBS_WINDOWS

    \e {This is used on Windows only.}

    This variable contains all windows libraries.The value of this
    variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LIBS_X11

    \e {This is used on Unix platforms only.}

    This variable contains all X11 libraries.The value of this
    variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LIBS_X11SM

    \e {This is used on Unix platforms only.}

    This variable contains all X11 session management libraries.  The
    value of this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LIB_FLAG

    This variable is not empty if the \c lib template is specified.  The
    value of this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_LINK_SHLIB_CMD

    This variable contains the command to execute when creating a
    shared library. The
    value of this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_POST_LINK

    This variable contains the command to execute after linking the TARGET
    together. This variable is normally empty and therefore nothing is
    executed, additionally some backends will not support this - mostly only
    Makefile backends.

    \section1 QMAKE_PRE_LINK

    This variable contains the command to execute before linking the TARGET
    together. This variable is normally empty and therefore nothing is
    executed, additionally some backends will not support this - mostly only
    Makefile backends.

    \section1 QMAKE_LN_SHLIB

    This variable contains the command to execute when creating a link
    to a shared library. The
    value of this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_MAC_SDK

    This variable is used on Mac OS X when building universal binaries.
    This process is described in more detail in the
    \l{Deploying an Application on Mac OS X#Architecture Dependencies}{Deploying
    an Application on Mac OS X} document.

    \section1 QMAKE_MACOSX_DEPLOYMENT_TARGET
    This variable only has an effect when building on Mac OS X. On that
    platform, the variable will be forwarded to the MACOSX_DEPLOYMENT_TARGET
    environment variable, which is interpreted by the compiler or linker.
    For more information, see the
    \l{Deploying an Application on Mac OS X#Mac OS X Version Dependencies}{Deploying
    an Application on Mac OS X} document.

    \section1 QMAKE_MAKEFILE

    This variable contains the name of the Makefile to create. The
    value of this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_MOC_SRC

    This variable contains the names of all moc source files to
    generate and include in the project. The value of this variable is
    typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_QMAKE

    This variable contains the location of qmake if it is not in the path.
    The value of this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_QT_DLL

    This variable is not empty if Qt was built as a dll.  The
    value of this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_RESOURCE_FLAGS

    This variable is used to customize the list of options passed to the
    \l{rcc}{Resource Compiler} in each of the build rules where it is used.
    For example, the following line ensures that the \c{-threshold} and
    \c{-compress} options are used with particular values each time that
    \c rcc is invoked:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 45

    \section1 QMAKE_RUN_CC

    This variable specifies the individual rule needed to build an object.
    The value of this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_RUN_CC_IMP

    This variable specifies the individual rule needed to build an object.
    The value of this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_RUN_CXX

    This variable specifies the individual rule needed to build an object.
    The value of this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_RUN_CXX_IMP

    This variable specifies the individual rule needed to build an object.
    The value of this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_TARGET

    This variable contains the name of the project target.  The value of
    this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 QMAKE_UIC

    This variable contains the location of uic if it is not in the path.
    The value of this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    It can be used to specify arguments to uic as well, such as additional plugin
    paths.  For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 46

    \section1 QT

    The values stored in the \c QT variable control which of the Qt modules are
    used by your project.

    The table below shows the options that can be used with the \c QT variable
    and the features that are associated with each of them:

    \table
    \header \o Option                     \o Features
    \row    \o core (included by default) \o QtCore module
    \row    \o gui  (included by default) \o QtGui module
    \row    \o network                    \o QtNetwork module
    \row    \o opengl                     \o QtOpenGL module
    \row    \o phonon                     \o Phonon Multimedia Framework
    \row    \o sql                        \o QtSql module
    \row    \o svg                        \o QtSvg module
    \row    \o xml                        \o QtXml module
    \row    \o webkit                     \o WebKit integration
    \row    \o qt3support                 \o Qt3Support module
    \endtable

    By default, \c QT contains both \c core and \c gui, ensuring that standard
    GUI applications can be built without further configuration.

    If you want to build a project \e without the QtGui module, you need to
    exclude the \c gui value with the "-=" operator; the following line will
    result in a minimal Qt project being built:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 47

    Note that adding the \c opengl option to the \c QT variable automatically
    causes the equivalent option to be added to the \c CONFIG variable.
    Therefore, for Qt applications, it is not necessary to add the \c opengl
    option to both \c CONFIG and \c{QT}.

    \section1 QTPLUGIN

    This variable contains a list of names of static plugins that are to be
    compiled with an application so that they are available as built-in
    resources.

    \target QT_VERSION
    \section1 QT_VERSION

    This variable contains the current version of Qt.

    \target QT_MAJOR_VERSION
    \section1 QT_MAJOR_VERSION

    This variable contains the current major version of Qt.

    \target QT_MINOR_VERSION
    \section1 QT_MINOR_VERSION

    This variable contains the current minor version of Qt.

    \target QT_PATCH_VERSION
    \section1 QT_PATCH_VERSION

    This variable contains the current patch version of Qt.

    \section1 RC_FILE

    This variable contains the name of the resource file for the application.
    The value of this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \target RCC_DIR
    \section1 RCC_DIR

    This variable specifies the directory where all intermediate
    resource files should be placed.

    For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 48

    \target REQUIRES
    \section1 REQUIRES

    This is a special variable processed by \c qmake.  If the
    contents of this variable do not appear in CONFIG by the time this
    variable is assigned, then a minimal Makefile will be generated that
    states what dependencies (the values assigned to REQUIRES) are
    missing.

    This is mainly used in Qt's build system for building the examples.

    \section1 RES_FILE

    This variable contains the name of the resource file for the application.
    The value of this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \target SIGNATURE_FILE
    \section1 SIGNATURE_FILE

    \e {This is only used on Windows CE.}

    Specifies which signature file should be used to sign the project target.

    \note This variable will overwrite the setting you have specified in configure,
    with the \c -signature option.

    \target SOURCES
    \section1 SOURCES

    This variable contains the name of all source files in the project.

    For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 49

    See also \l{#HEADERS}{HEADERS}

    \section1 SRCMOC

    This variable is set by \c qmake if files can be found that
    contain the Q_OBJECT macro.  \c SRCMOC contains the
    name of all the generated moc files. The value of this variable
    is typically handled by \c qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs to be
    modified.

    \target SUBDIRS
    \section1 SUBDIRS

    This variable, when used with the \l{#TEMPLATE}{\c subdirs template}
    contains the names of all subdirectories that contain parts of the project
    that need be built. Each subdirectory must contain its own project file.

    For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 50

    It is essential that the project file in each subdirectory has the same
    name as the subdirectory itself, so that \c qmake can find it.
    For example, if the subdirectory is called \c myapp then the project file
    in that directory should be called \c myapp.pro.

    If you need to ensure that the subdirectories are built in the order in
    which they are specified, update the \l{#CONFIG}{CONFIG} variable to
    include the \c ordered option:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 51

    \target TARGET
    \section1 TARGET

    This specifies the name of the target file.

    For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 52

    The project file above would produce an executable named \c myapp on
    unix and 'myapp.exe' on windows.

    \section1 TARGET_EXT

    This variable specifies the target's extension.  The value of this variable
    is typically handled by \c qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs to be
    modified.

    \section1 TARGET_x

    This variable specifies the target's extension with a major version number.  The value of this variable
    is typically handled by \c qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs to be
    modified.

    \section1 TARGET_x.y.z

    This variable specifies the target's extension with version number.  The value of this variable
    is typically handled by \c qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs to be
    modified.

    \target TEMPLATE
    \section1 TEMPLATE

    This variable contains the name of the template to use when
    generating the project.  The allowed values are:

    \table
    \header \o Option \o Description
    \row    \o app    \o Creates a Makefile for building applications (the default). (See
            \l{qmake Common Projects#Application}{qmake Common Projects} for more information.)
    \row    \o lib    \o Creates a Makefile for building libraries. (See
            \l{qmake Common Projects#Library}{qmake Common Projects} for more information.)
    \row    \o subdirs \o Creates a Makefile for building targets in subdirectories.
            The subdirectories are specified using the \l{#SUBDIRS}{SUBDIRS}
            variable.
    \row    \o vcapp  \o \e {Windows only} Creates an application project for Visual Studio.
            (See \l{qmake Platform Notes#Creating Visual Studio Project Files}{qmake Platform Notes}
            for more information.)
    \row    \o vclib  \o \e {Windows only} Creates a library project for Visual Studio.
            (See \l{qmake Platform Notes#Creating Visual Studio Project Files}{qmake Platform Notes}
            for more information.)
    \endtable

    For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 53

    The template can be overridden by specifying a new template type with the
    \c -t command line option. This overrides the template type \e after the .pro
    file has been processed. With .pro files that use the template type to
    determine how the project is built, it is necessary to declare TEMPLATE on
    the command line rather than use the \c -t option.

    \section1 TRANSLATIONS

    This variable contains a list of translation (.ts) files that contain
    translations of the user interface text into non-native languages.

    See the \l{Qt Linguist Manual} for more information about
    internationalization (i18n) and localization (l10n) with Qt.

    \section1 UICIMPLS

    This variable contains a list of the generated implementation files by UIC.
    The value of this variable
    is typically handled by \c qmake or \l{#QMAKESPEC}{qmake.conf} and rarely needs to be
    modified.

    \section1 UICOBJECTS

    This variable is generated from the UICIMPLS variable.  The extension of each
    file will have been replaced by .o (Unix) or .obj (Win32).  The value of this variable is
    typically handled by \c qmake or \l{#QMAKESPEC}{qmake.conf} and
    rarely needs to be modified.

    \target UI_DIR
    \section1 UI_DIR

    This variable specifies the directory where all intermediate files from uic
    should be placed. This variable overrides both UI_SOURCES_DIR and
    UI_HEADERS_DIR.

    For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 54

    \target UI_HEADERS_DIR
    \section1 UI_HEADERS_DIR

    This variable specifies the directory where all declaration files (as
    generated by uic) should be placed.

    For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 55

    \target UI_SOURCES_DIR
    \section1 UI_SOURCES_DIR

    This variable specifies the directory where all implementation files (as generated
    by uic) should be placed.

    For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 56

    \target VERSION
    \section1 VERSION

    This variable contains the version number of the application or library if
    either the \c app \l{#TEMPLATE}{TEMPLATE} or the \c lib \l{#TEMPLATE}{TEMPLATE}
    is specified.

    For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 57

    \section1 VER_MAJ

    This variable contains the major version number of the library, if the
    \c lib \l{#TEMPLATE}{template} is specified.

    \section1 VER_MIN

    This variable contains the minor version number of the library, if the
    \c lib \l{#TEMPLATE}{template} is specified.

    \section1 VER_PAT

    This variable contains the patch version number of the library, if the
    \c lib \l{#TEMPLATE}{template} is specified.

    \section1 VPATH

    This variable tells \c qmake where to search for files it cannot
    open. With this you may tell \c qmake where it may look for things
    like SOURCES, and if it finds an entry in SOURCES that cannot be
    opened it will look through the entire VPATH list to see if it can
    find the file on its own.

    See also \l{#DEPENDPATH}{DEPENDPATH}.

    \section1 YACCIMPLS

    This variable contains a list of yacc source files. The value of
    this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \section1 YACCOBJECTS

    This variable contains a list of yacc object files. The value of
    this variable is typically handled by \c qmake or
     \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.

    \target YACCSOURCES
    \section1 YACCSOURCES

    This variable contains a list of yacc source files to be included
    in the project.  All dependencies, headers and source files will
    automatically be included in the project.

    For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 58

    \section1 _PRO_FILE_

    This variable contains the path to the project file in use.

    For example, the following line causes the location of the project
    file to be written to the console:

    \snippet doc/src/snippets/qmake/project_location.pro project file

    \section1 _PRO_FILE_PWD_

    This variable contains the path to the directory containing the project
    file in use.

    For example, the following line causes the location of the directory
    containing the project file to be written to the console:

    \snippet doc/src/snippets/qmake/project_location.pro project file directory
*/

/*!
    \page qmake-function-reference.html
    \title qmake Function Reference
    \contentspage {qmake Manual}{Contents}
    \previouspage qmake Variable Reference
    \nextpage Configuring qmake's Environment

    \c qmake provides built-in functions to allow the contents of
    variables to be processed, and to enable tests to be performed
    during the configuration process. Functions that process the
    contents of variables typically return values that can be assigned
    to other variables, and these values are obtained by prefixing
    function with the \c $$ operator. Functions that perform tests
    are usually used as the conditional parts of scopes; these are
    indicated in the function descriptions below.

    \tableofcontents{2}

    \section1 basename(variablename)

    Returns the basename of the file specified. For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 59

    \section1 CONFIG(config)
    [Conditional]

    This function can be used to test for variables placed into the
    \c CONFIG variable. This is the same as regular old style (tmake) scopes,
    but has the added advantage a second parameter can be passed to test for
    the active config. As the order of values is important in \c CONFIG
    variables (i.e. the last one set will be considered the active config for
    mutually exclusive values) a second parameter can be used to specify a set
    of values to consider. For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 60

    Because release is considered the active setting (for feature parsing)
    it will be the CONFIG used to generate the build file. In the common
    case a second parameter is not needed, but for specific mutual
    exclusive tests it is invaluable.

    \section1 contains(variablename, value)
    [Conditional]

    Succeeds if the variable \e variablename contains the value \e value;
    otherwise fails. You can check the return value of this function using
    a scope.

    For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 61

    The contents of the scope are only processed if the \c drivers
    variable contains the value, \c network. If this is the case, the
    appropriate files are added to the \c SOURCES and \c HEADERS
    variables.

    \section1 count(variablename, number)
    [Conditional]

    Succeeds if the variable \e variablename contains a list with the
    specified \e number of value; otherwise fails.

    This function is used to ensure that declarations inside a scope are
    only processed if the variable contains the correct number of values;
    for example:

    \snippet doc/src/snippets/qmake/functions.pro 2

    \section1 dirname(file)

    Returns the directory name part of the specified file. For example:

    \snippet doc/src/snippets/qmake/dirname.pro 0

    \section1 error(string)

    This function never returns a value. \c qmake displays the given
    \e string to the user, and exits. This function should only be used
    for unrecoverable errors.

    For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 62

    \section1 eval(string)
    [Conditional]

    Evaluates the contents of the string using \c qmake's syntax rules
    and returns true.
    Definitions and assignments can be used in the string to modify the
    values of existing variables or create new definitions.

    For example:
    \snippet doc/src/snippets/qmake/functions.pro 4

    Note that quotation marks can be used to delimit the string, and that
    the return value can be discarded if it is not needed.

    \section1 exists(filename)
    [Conditional]

    Tests whether a file with the given \e filename exists.
    If the file exists, the function succeeds; otherwise it fails.
    If a regular expression is specified for the filename, this function
    succeeds if any file matches the regular expression specified.

    For example:
    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 63

    Note that "/" can be used as a directory separator, regardless of the
    platform in use.

    \section1 find(variablename, substr)

    Places all the values in \e variablename that match \e substr. \e
    substr may be a regular expression, and will be matched accordingly.

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 64

    MY_VAR2 will contain '-Lone -Ltwo -Lthree -Lfour -Lfive', and MY_VAR3 will
    contains 'three two three'.

    \section1 for(iterate, list)

    This special test function will cause a loop to be started that
    iterates over all values in \e list, setting \e iterate to each
    value in turn. As a convenience, if \e list is 1..10 then iterate will
    iterate over the values 1 through 10.

    The use of an else scope afer a condition line with a for() loop is
    disallowed.

    For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 65

    \section1 include(filename)
    [Conditional]

    Includes the contents of the file specified by \e filename into the
    current project at the point where it is included. This function
    succeeds if \e filename is included; otherwise it fails. The included
    file is processed immediately.

    You can check whether the file was included by using this function as
    the condition for a scope; for example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 66

    \section1 infile(filename, var, val)
    [Conditional]

    Succeeds if the file \e filename (when parsed by \c qmake itself)
    contains the variable \e var with a value of \e val; otherwise fails.
    If you do not specify a third argument (\e val), the function will
    only test whether \e var has been declared in the file.

    \section1 isEmpty(variablename)
    [Conditional]

    Succeeds if the variable \e variablename is empty; otherwise fails.
    This is the equivalent of \c{count( variablename, 0 )}.

    For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 67

    \section1 join(variablename, glue, before, after)

    Joins the value of \e variablename with \c glue. If this value is
    non-empty it prefixes the value with \e before and suffix it with \e
    after. \e variablename is the only required field, the others default
    to empty strings. If you need to encode spaces in \e glue, \e before, or \e
    after you must quote them.

    \section1 member(variablename, position)

    Returns the value at the given \e position in the list of items in
    \e variablename.
    If an item cannot be found at the position specified, an empty string is
    returned. \e variablename is the only required field. If not specified,
    \c position defaults to 0, causing the first value in the list to be
    returned.

    \section1 message(string)

    This function simply writes a message to the console. Unlike the
    \c error() function, this function allows processing to continue.

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 68

    The above line causes "This is a message" to be written to the console.
    The use of quotation marks is optional.

    \note By default, messages are written out for each Makefile generated by
    qmake for a given project. If you want to ensure that messages only appear
    once for each project, test the \c build_pass variable
    \l{qmake Advanced Usage}{in conjunction with a scope} to filter out
    messages during builds; for example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 69

    \section1 prompt(question)

    Displays the specified \e question, and returns a value read from stdin.

    \section1 quote(string)

    Converts a whole \e string into a single entity and returns the result.
    Newlines, carriage returns, and tabs can be specified in the string
    with \\n \\r and \\t. The return value does not contain either single
    or double quotation marks unless you explicitly include them yourself,
    but will be placed into a single entry (for literal expansion).

    \section1 replace(string, old_string, new_string)

    Replaces each instance of \c old_string with \c new_string in the
    contents of the variable supplied as \c string. For example, the
    code

    \snippet doc/src/snippets/qmake/replace.pro 0

    prints the message:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 70

    \section1 sprintf(string, arguments...)

    Replaces %1-%9 with the arguments passed in the comma-separated list
    of function \e arguments and returns the processed string.

    \section1 system(command)
    [Conditional]

    Executes the given \c command in a secondary shell, and succeeds
    if the command returns with a zero exit status; otherwise fails.
    You can check the return value of this function using a scope:

    For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 71

    Alternatively, you can use this function to obtain stdout and stderr
    from the command, and assign it to a variable. For example, you can
    use this to interrogate information about the platform:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 72

    \target unique
    \section1 unique(variablename)

    This will return a list of values in variable that are unique (that is
    with repetitive entries removed). For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 73

    \section1 warning(string)

    This function will always succeed, and will display the given
    \e string to the user. message() is a synonym for warning().
*/

/*!
    \page qmake-environment-reference.html
    \contentspage {qmake Manual}{Contents}
    \previouspage qmake Function Reference

    \title Configuring qmake's Environment

    \tableofcontents

    \target Properties
    \section1 Properties

    \c qmake has a system of persistant information, this allows you to
    \c set a variable in qmake once, and each time qmake is invoked this
    value can be queried. Use the following to set a property in qmake:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 74

    The appropriate variable and value should be substituted for
    \c VARIABLE and \c VALUE.

    To retrieve this information back from qmake you can do:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 75

    \note \c{qmake -query} will only list variables that you have
    previously set with \c{qmake -set VARIABLE VALUE}.

    This information will be saved into a QSettings object (meaning it
    will be stored in different places for different platforms). As
    \c VARIABLE is versioned as well, you can set one value in an older
    version of \c qmake, and newer versions will retrieve this value. However,
    if you set \c VARIABLE for a newer version of \c qmake, the older version
    will not use this value. You can however query a specific version of a
    variable if you prefix that version of \c qmake to \c VARIABLE, as in
    the following example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 76

    \c qmake also has the notion of \c builtin properties, for example you can
    query the installation of Qt for this version of \c qmake with the
    \c QT_INSTALL_PREFIX property:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 77

    These built-in properties cannot have a version prefixed to them as
    they are not versioned, and each version of \c qmake will have its own
    built-in set of these values. The list below outlines the built-in
    properties:

    \list
    \o \c QT_INSTALL_PREFIX - Where the version of Qt this qmake is built for resides
    \o \c QT_INSTALL_DATA - Where data for this version of Qt resides
    \o \c QMAKE_VERSION - The current version of qmake
    \endlist

    Finally, these values can be queried in a project file with a special
    notation such as:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 78

    \target QMAKESPEC
    \section1 QMAKESPEC

    \c qmake requires a platform and compiler description file which
    contains many default values used to generate appropriate Makefiles.
    The standard Qt distribution comes with many of these files, located
    in the \c mkspecs subdirectory of the Qt installation.

    The \c QMAKESPEC environment variable can contain any of the following:

    \list
    \o A complete path to a directory containing a \c{qmake.conf} file.
       In this case \c qmake will open the \c{qmake.conf} file from within that
       directory.  If the file does not exist, \c qmake will exit with an
       error.
    \o The name of a platform-compiler combination. In this case, \c qmake
       will search in the directory specified by the \c mkspecs subdirectory
       of the data path specified when Qt was compiled (see
       QLibraryInfo::DataPath).
    \endlist

    \bold{Note:} The \c QMAKESPEC path will automatically be added to the
    \l{qmake Variable Reference#INCLUDEPATH}{INCLUDEPATH} system variable.

    \target INSTALLS
    \section1 INSTALLS

    It is common on Unix to also use the build tool to install applications
    and libraries; for example, by invoking \c{make install}. For this reason,
    \c qmake has the concept of an install set, an object which contains
    instructions about the way part of a project is to be installed.
    For example, a collection of documentation files can be described in the
    following way:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 79

    The \c path member informs \c qmake that the files should be installed in
    \c /usr/local/program/doc (the path member), and the \c files member
    specifies the files that should be copied to the installation directory.
    In this case, everything in the \c docs directory will be coped to
    \c /usr/local/program/doc.

    Once an install set has been fully described, you can append it to the
    install list with a line like this:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 80

    \c qmake will ensure that the specified files are copied to the installation
    directory. If you require greater control over this process, you can also
    provide a definition for the \c extra member of the object. For example,
    the following line tells \c qmake to execute a series of commands for this
    install set:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 81

    The \c unix scope
    (see \l{qmake Advanced Usage#Scopes and Conditions}{Scopes and Conditions})
    ensures that these particular commands are only executed on Unix platforms.
    Appropriate commands for other platforms can be defined using other scope
    rules.

    Commands specified in the \c extra member are executed before the instructions
    in the other members of the object are performed.

    If you append a built-in install set to the \c INSTALLS variable and do
    not specify \c files or \c extra members, \c qmake will decide what needs to
    be copied for you. Currently, the only supported built-in install set is
    \c target:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 82

    In the above lines, \c qmake knows what needs to be copied, and will handle
    the installation process automatically.

    \target cache
    \section1 Cache File

    The cache file is a special file \c qmake reads to find settings not specified
    in the \c qmake.conf file, project files, or at the command line. If
    \c -nocache is not specified when \c qmake is run, it will try to find a file
    called \c{.qmake.cache} in parent directories of the current directory. If
    it fails to find this file, it will silently ignore this step of processing.

    If it finds a \c{.qmake.cache} file then it will process this file first before
    it processes the project file.

    \target LibDepend
    \section1 Library Dependencies

    Often when linking against a library, \c qmake relies on the underlying
    platform to know what other libraries this library links against, and
    lets the platform pull them in. In many cases, however, this is not
    sufficent. For example, when statically linking a library, no other
    libraries are linked to, and therefore no dependencies to those
    libraries are created. However, an application that later links
    against this library will need to know where to find the symbols that
    the static library will require. To help with this situation, \c qmake
    attempts to follow a library's dependencies where appropriate, but
    this behavior must be explicitly enabled by following two steps.

    The first step is to enable dependency tracking in the library itself.
    To do this you must tell \c qmake to save information about the library:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 83

    This is only relevant to the \c lib template, and will be ignored for
    all others. When this option is enabled, \c qmake will create a file
    ending in .prl which will save some meta-information about the
    library. This metafile is just like an ordinary project file, but only
    contains internal variable declarations. You are free to view this file
    and, if it is deleted, \c qmake will know to recreate it when necessary,
    either when the project file is later read, or if a dependent library
    (described below) has changed. When installing this library, by
    specifying it as a target in an \c INSTALLS declaration, \c qmake will
    automatically copy the .prl file to the installation path.

    The second step in this process is to enable reading of this meta
    information in the applications that use the static library:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 84

    When this is enabled, \c qmake will process all libraries linked to
    by the application and find their meta-information. \c qmake will use
    this to determine the relevant linking information, specifically adding
    values to the application project file's list of \c DEFINES as well as
    \c LIBS. Once \c qmake has processed this file, it will then look through
    the newly introduced libraries in the \c LIBS variable, and find their
    dependent .prl files, continuing until all libraries have been resolved.
    At this point, the Makefile is created as usual, and the libraries are
    linked explicitlyy against the application.

    The internals of the .prl file are left closed so they can easily
    change later. They are not designed to be changed by hand, should only
    be created by \c qmake, and should not be transferred between operating
    systems as they may contain platform-dependent information.

    \target Extensions
    \section1 File Extensions

    Under normal circumstances \c qmake will try to use appropriate file extensions
    for your platform. However, it is sometimes necessary to override the default
    choices for each platform and explicitly define file extensions for \c qmake to use.
    This is achieved by redefining certain built-in variables; for example the extension
    used for \l moc files can be redefined with the following assignment in a project
    file:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 85

    The following variables can be used to redefine common file extensions recognized
    by \c qmake:

    \list
    \o QMAKE_EXT_MOC - This modifies the extension placed on included moc files.
    \o QMAKE_EXT_UI - This modifies the extension used for designer UI files (usually
                      in \c FORMS).
    \o QMAKE_EXT_PRL - This modifies the extension placed on
                       \l{#LibDepend}{library dependency files}.
    \o QMAKE_EXT_LEX - This changes the suffix used in files (usually in \c LEXSOURCES).
    \o QMAKE_EXT_YACC - This changes the suffix used in files (usually in \c YACCSOURCES).
    \o QMAKE_EXT_OBJ - This changes the suffix used on generated object files.
    \endlist

    All of the above accept just the first value, so you must assign to it just one
    value that will be used throughout your project file. There are two variables that
    accept a list of values:

    \list
    \o QMAKE_EXT_CPP - Causes \c qmake to interpret all files with these suffixes as
                       C++ source files.
    \o QMAKE_EXT_H - Causes \c qmake to interpret all files with these suffixes as
                     C and C++ header files.
    \endlist

    \target Customizing
    \section1 Customizing Makefile Output

    \c qmake tries to do everything expected of a cross-platform build tool.
    This is often less than ideal when you really need to run special
    platform-dependent commands. This can be achieved with specific instructions
    to the different \c qmake backends.

    Customization of the Makefile output is performed through an object-style
    API as found in other places in \c qmake. Objects are defined automatically
    by specifying their members; for example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 86

    The definitions above define a \c qmake target called \c mytarget, containing
    a Makefile target called \c{.buildfile} which in turn is generated with
    the \c touch command. Finally, the \c{.depends} member specifies that
    \c mytarget depends on \c mytarget2, another target that is defined afterwards.
    \c mytarget2 is a dummy target; it is only defined to echo some text to
    the console.

    The final step is to instruct \c qmake that this object is a target to be built:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 87

    This is all you need to do to actually build custom targets. Of course, you may
    want to tie one of these targets to the
    \l{qmake Variable Reference#TARGET}{qmake build target}. To do this, you simply need to
    include your Makefile target in the list of
    \l{qmake Variable Reference#PRE_TARGETDEPS}{PRE_TARGETDEPS}.

    The following tables are an overview of the options available to you with the QMAKE_EXTRA_TARGETS
    variable.

    \table
    \header
        \o Member
        \o Description
    \row
        \o commands
        \o The commands for generating the custom build target.
    \row
        \o CONFIG
        \o Specific configuration options for the custom build target.  See the CONFIG table for details.
    \row
        \o depends
        \o The existing build targets that the custom build target depends on.
    \row
        \o recurse
        \o Specifies which sub-targets should used when creating the rules in the Makefile to call in
           the sub-target specific Makefile.  This is only used when \c recursive is set in the CONFIG.
    \row
        \o recurse_target
        \o Specifies the target that should be built via the sub-target Makefile for the rule in the Makefile.
           This adds something like $(MAKE) -f Makefile.[subtarget] [recurse_target].  This is only used when
           \c recursive is set in the CONFIG.
    \row
        \o target
        \o The file being created by the custom build target.
    \endtable

    List of members specific to the CONFIG option:

    \table
    \header
        \o Member
        \o Description
    \row
        \o recursive
        \o Indicates that rules should be created in the Makefile and thus call
           the relevant target inside the sub-target specific Makefile.  This defaults to creating
           an entry for each of the sub-targets.
    \endtable

    For convenience, there is also a method of customizing projects
    for new compilers or preprocessors:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 88

    With the above definitions, you can use a drop-in replacement for moc if one
    is available. The commands is executed on all arguments given to the
    \c NEW_HEADERS variable (from the \c input member), and the result is written
    to the file defined by the \c output member; this file is added to the
    other source files in the project.
    Additionally, \c qmake will execute \c depend_command to generate dependency
    information, and place this information in the project as well.

    These commands can easily be placed into a cache file, allowing subsequent
    project files to add arguments to \c NEW_HEADERS.

    The following tables are an overview of the options available to you with the QMAKE_EXTRA_COMPILERS
    variable.

    \table
    \header
        \o Member
        \o Description
    \row
        \o commands
        \o The commands used for for generating the output from the input.
    \row
        \o CONFIG
        \o Specific configuration options for the custom compiler.  See the CONFIG table for details.
    \row
        \o depend_command
        \o Specifies a command used to generate the list of dependencies for the output.
    \row
        \o dependency_type
        \o Specifies the type of file the output is, if it is a known type (such as TYPE_C,
           TYPE_UI, TYPE_QRC) then it is handled as one of those type of files.
    \row
        \o depends
        \o Specifies the dependencies of the output file.
    \row
        \o input
        \o The variable that contains the files that should be processed with the custom compiler.
    \row
        \o name
        \o A description of what the custom compiler is doing.  This is only used in some backends.
    \row
        \o output
        \o The filename that is created from the custom compiler.
    \row
        \o output_function
        \o Specifies a custom qmake function that is used to specify the filename to be created.
    \row
        \o variables
        \o Indicates that the variables specified here are replaced with $(QMAKE_COMP_VARNAME) when refered to
           in the pro file as $(VARNAME).
    \row
        \o variable_out
        \o The variable that the files created from the output should be added to.
    \endtable

    List of members specific to the CONFIG option:

    \table
    \header
        \o Member
        \o Description
    \row
        \o combine
        \o Indicates that all of the input files are combined into a single output file.
    \row
        \o target_predeps
        \o Indicates that the output should be added to the list of PRE_TARGETDEPS.
    \row
        \o explicit_dependencies
        \o The dependencies for the output only get generated from the depends member and from
           nowhere else.
    \row
        \o no_link
        \o Indicates that the output should not be added to the list of objects to be linked in
    \endtable
*/

/*!
    \page qmake-advanced-usage.html
    \title qmake Advanced Usage
    \contentspage {qmake Manual}{Contents}
    \previouspage qmake Platform Notes
    \nextpage Using Precompiled Headers

    Many \c qmake project files simply describe the sources and header files used
    by the project, using a list of \c{name = value} and \c{name += value}
    definitions. \c qmake also provides other operators, functions, and scopes
    that can be used to process the information supplied in variable declarations.
    These advanced features allow Makefiles to be generated for multiple platforms
    from a single project file.

    \tableofcontents

    \section1 Operators

    In many project files, the assignment (\c{=}) and append (\c{+=}) operators can
    be used to include all the information about a project. The typical pattern of
    use is to assign a list of values to a variable, and append more values
    depending on the result of various tests. Since \c qmake defines certain
    variables using default values, it is sometimes necessary to use the removal
    (\c{-=}) operator to filter out values that are not required. The following
    operators can be used to manipulate the contents of variables.

    The \c = operator assigns a value to a variable:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 89

    The above line sets the \c TARGET variable to \c myapp. This will overwrite any
    values previously set for \c TARGET with \c myapp.

    The \c += operator appends a new value to the list of values in a variable:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 90

    The above line appends \c QT_DLL to the list of pre-processor defines to be put
    in the generated Makefile.

    The \c -= operator removes a value from the list of values in a variable:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 91

    The above line removes \c QT_DLL from the list of pre-processor defines to be
    put in the generated Makefile.

    The \c *= operator adds a value to the list of values in a variable, but only
    if it is not already present. This prevents values from being included many
    times in a variable. For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 92

    In the above line, \c QT_DLL will only be added to the list of pre-processor
    defines if it is not already defined. Note that the
    \l{qmake Function Reference#unique}{unique()}
    function can also be used to ensure that a variables only contains one
    instance of each value.

    The \c ~= operator replaces any values that match a regular expression with
    the specified value:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 93

    In the above line, any values in the list that start with \c QT_D or \c QT_T are
    replaced with \c QT.

    The \c $$ operator is used to extract the contents of a variable, and can be
    used to pass values between variables or supply them to functions:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 94

    \target Scopes
    \section1 Scopes

    Scopes are similar to \c if statements in procedural programming languages.
    If a certain condition is true, the declarations inside the scope are processed.

    \section2 Syntax

    Scopes consist of a condition followed by an opening brace on the same line,
    a sequence of commands and definitions, and a closing brace on a new line:

    \snippet doc/src/snippets/qmake/scopes.pro syntax

    The opening brace \e{must be written on the same line as the condition}.
    Scopes may be concatenated to include more than one condition; see below
    for examples.

    \section2 Scopes and Conditions

    A scope is written as a condition followed by a series of declarations
    contained within a pair of braces; for example:

    \snippet doc/src/snippets/qmake/scopes.pro 0

    The above code will add the \c paintwidget_win.cpp file to the sources listed
    in the generated Makefile if \c qmake is used on a Windows platform.
    If \c qmake is used on a platform other than Windows, the define will be
    ignored.

    The conditions used in a given scope can also be negated to provide an
    alternative set of declarations that will be processed only if the
    original condition is false. For example, suppose we want to process
    something on all platforms \e except for Windows. We can achieve this by
    negating the scope like this:

    \snippet doc/src/snippets/qmake/scopes.pro 1

    Scopes can be nested to combine more than one condition. For instance, if
    you want to include a particular file for a certain platform only if
    debugging is enabled then you write the following:

    \snippet doc/src/snippets/qmake/scopes.pro 2

    To save writing many nested scopes, you can nest scopes using the \c :
    operator. The nested scopes in the above example can be rewritten in
    the following way:

    \snippet doc/src/snippets/qmake/scopes.pro 3

    You may also use the \c : operator to perform single line conditional
    assignments; for example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 95

    The above line adds \c QT_DLL to the \c DEFINES variable only on the
    Windows platform.
    Generally, the \c : operator behaves like a logical AND operator, joining
    together a number of conditions, and requiring all of them to be true.

        There is also the \c | operator to act like a logical OR operator, joining 
        together a number of conditions, and requiring only one of them to be true.

        \snippet doc/src/snippets/qmake/scopes.pro 4

    You can also provide alternative declarations to those within a scope by
    using an \c else scope. Each \c else scope is processed if the conditions
    for the preceding scopes are false.
    This allows you to write complex tests when combined with other scopes
    (separated by the \c : operator as above). For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 96

    \section2 Configuration and Scopes

    The values stored in the
    \l{qmake-project-files.html#GeneralConfiguration}{\c CONFIG variable}
    are treated specially by \c qmake. Each of the possible values can be
    used as the condition for a scope. For example, the list of values
    held by \c CONFIG can be extended with the \c opengl value:

    \snippet doc/src/snippets/qmake/configscopes.pro 0

    As a result of this operation, any scopes that test for \c opengl will
    be processed. We can use this feature to give the final executable an
    appropriate name:

    \snippet doc/src/snippets/qmake/configscopes.pro 1
    \snippet doc/src/snippets/qmake/configscopes.pro 2
    \snippet doc/src/snippets/qmake/configscopes.pro 3

    This feature makes it easy to change the configuration for a project
    without losing all the custom settings that might be needed for a specific
    configuration. In the above code, the declarations in the first scope are
    processed, and the final executable will be called \c application-gl.
    However, if \c opengl is not specified, the declarations in the second
    scope are processed instead, and the final executable will be called
    \c application.

    Since it is possible to put your own values on the \c CONFIG
    line, this provides you with a convenient way to customize project files
    and fine-tune the generated Makefiles.

    \section2 Platform Scope Values

    In addition to the \c win32, \c macx, and \c unix values used in many
    scope conditions, various other built-in platform and compiler-specific
    values can be tested with scopes. These are based on platform
    specifications provided in Qt's \c mkspecs directory. For example, the
    following lines from a project file show the current specification in
    use and test for the \c linux-g++ specification:

    \snippet doc/src/snippets/qmake/specifications.pro 0

    You can test for any other platform-compiler combination as long as a
    specification exists for it in the \c mkspecs directory.

    \section1 Variables

    Many of the variables used in project files are special variables that
    \c qmake uses when generating Makefiles, such as \c DEFINES, \c SOURCES,
    and \c HEADERS. It is possible for you to create variables for your own
    use; \c qmake creates new variables with a given name when it encounters
    an assignment to that name. For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 97

    There are no restricitions on what you do to your own variables, as \c
    qmake will ignore them unless it needs to evaluate them when processing
    a scope.

    You can also assign the value of a current variable to another
    variable by prefixing $$ to the variable name. For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 98

    Now the MY_DEFINES variable contains what is in the DEFINES variable at
    this point in the project file.  This is also equivalent to:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 99

    The second notation allows you to append the contents of the variable to
    another value without separating the two with a space. For example, the
    following will ensure that the final executable will be given a name
    that includes the project template being used:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 100

    Variables can be used to store the contents of environment variables.
    These can be evaluated at the time that \c qmake is run, or included
    in the generated Makefile for evaluation when the project is built.

    To obtain the contents of an environment value when \c qmake is run,
    use the \c $$(...) operator:

    \snippet doc/src/snippets/qmake/environment.pro 0

    In the above assignment, the value of the \c PWD environment variable
    is read when the project file is processed.

    To obtain the contents of an environment value at the time when the
    generated Makefile is processed, use the \c $(...) operator:

    \snippet doc/src/snippets/qmake/environment.pro 1

    In the above assignment, the value of \c PWD is read immediately
    when the project file is processed, but \c $(PWD) is assigned to
    \c DESTDIR in the generated Makefile. This makes the build process
    more flexible as long as the environment variable is set correctly
    when the Makefile is processed.

    The special \c $$[...] operator can be used to access various
    configuration options that were set when Qt was built:

    \snippet doc/src/snippets/qmake/qtconfiguration.pro 0

    The variables accessible with this operator are typically used to
    enable third party plugins and components to be integrated with Qt.
    For example, a \QD plugin can be installed alongside \QD's built-in
    plugins if the following declaration is made in its project file:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 101

    \target VariableProcessingFunctions
    \section1 Variable Processing Functions

    \c qmake provides a selection of built-in functions to allow the
    contents of variables to be processed. These functions process the
    arguments supplied to them and return a value, or list of values, as
    a result. In order to assign a result to a variable, it is necessary
    to use the \c $$ operator with this type of function in the same way
    used to assign contents of one variable to another:

    \snippet doc/src/snippets/qmake/functions.pro 1

    This type of function should be used on the right-hand side of
    assignments (i.e, as an operand).

    It is possible to define your own functions for processing the
    contents of variables. These functions can be defined in the following
    way:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 102

    The following example function takes a variable name as its only
    argument, extracts a list of values from the variable with the
    \l{qmake-function-reference.html}{eval()} built-in function,
    and compiles a list of files:

    \snippet doc/src/snippets/qmake/replacefunction.pro 0

    \target ConditionalFunctions
    \section1 Conditional Functions

    \c qmake provides built-in functions that can be used as conditions
    when writing scopes. These functions do not return a value, but
    instead indicate "success" or "failure":

    \snippet doc/src/snippets/qmake/functions.pro 3

    This type of function should be used in conditional expressions
    only.

    It is possible to define your own functions to provide conditions
    for scopes. The following example tests whether each file in a list
    exists and returns true if they all exist, or false if not:

    \snippet doc/src/snippets/qmake/testfunction.pro 0

    \section1 Adding New Configuration Features

    \c qmake lets you create your own \e features that can be included in
    project files by adding their names to the list of values specified by
    the \c CONFIG variable. Features are collections of custom functions and
    definitions in \c{.prf} files that can reside in one of many standard
    directories. The locations of these directories are defined in a number
    of places, and \c qmake checks each of them in the following order when
    it looks for \c{.prf} files:

    \list 1
    \o In a directory listed in the \c QMAKEFEATURES environment variable;
       this contains a colon-separated list of directories.
    \o In a directory listed in the \c QMAKEFEATURES property variable; this
       contains a colon-spearated list of directories.
    \omit
    \o In a features directory beneath the project's root directory (where
       the \c{.qmake.cache} file is generated).
    \endomit
    \o In a features directory residing within a \c mkspecs directory.
       \c mkspecs directories can be located beneath any of the directories
       listed in the \c QMAKEPATH environment variable (a colon-separated list
       of directories). (\c{$QMAKEPATH/mkspecs/<features>})
    \o In a features directory residing beneath the directory provided by the
       \c QMAKESPEC environment variable. (\c{$QMAKESPEC/<features>})
    \o In a features directory residing in the \c data_install/mkspecs directory.
       (\c{data_install/mkspecs/<features>})
    \o In a features directory that exists as a sibling of the directory
       specified by the \c QMAKESPEC environment variable.
       (\c{$QMAKESPEC/../<features>})
    \endlist

    The following features directories are searched for features files:

    \list 1
    \o \c{features/unix}, \c{features/win32}, or \c{features/macx}, depending on
       the platform in use
    \o \c features/
    \endlist

    For example, consider the following assignment in a project file:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 103

    With this addition to the \c CONFIG variable, \c qmake will search the
    locations listed above for the \c myfeatures.prf file after it has
    finished parsing your project file. On Unix systems, it will look for
    the following file:

    \list 1
    \o \c $QMAKEFEATURES/myfeatures.prf (for each directory listed in the
       \c QMAKEFEATURES environment variable)
    \o \c $$QMAKEFEATURES/myfeatures.prf (for each directory listed in the
       \c QMAKEFEATURES property variable)
    \o \c myfeatures.prf (in the project's root directory)
    \o \c $QMAKEPATH/mkspecs/features/unix/myfeatures.prf and
       \c $QMAKEPATH/mkspecs/features/myfeatures.prf (for each directory
       listed in the \c QMAKEPATH environment variable)
    \o \c $QMAKESPEC/features/unix/myfeatures.prf and
       \c $QMAKESPEC/features/myfeatures.prf
    \o \c data_install/mkspecs/features/unix/myfeatures.prf and
       \c data_install/mkspecs/features/myfeatures.prf
    \o \c $QMAKESPEC/../features/unix/myfeatures.prf and
       \c $QMAKESPEC/../features/myfeatures.prf
    \endlist

    \note The \c{.prf} files must have names in lower case.


*/

/*!
    \page qmake-precompiledheaders.html
    \title Using Precompiled Headers
    \contentspage {qmake Manual}{Contents}
    \previouspage qmake Advanced Usage
    \nextpage qmake Reference
    \ingroup buildsystem

    \target Introduction

    Precompiled headers are a performance feature supported by some
    compilers to compile a stable body of code, and store the compiled
    state of the code in a binary file. During subsequent compilations,
    the compiler will load the stored state, and continue compiling the
    specified file. Each subsequent compilation is faster because the
    stable code does not need to be recompiled.

    \c qmake supports the use of precompiled headers (PCH) on some
    platforms and build environments, including:
    \list
    \o Windows
        \list
        \o nmake
        \o Dsp projects (VC 6.0)
        \o Vcproj projects (VC 7.0 \& 7.1)
        \endlist
    \o Mac OS X
        \list
        \o Makefile
        \o Xcode
        \endlist
    \o Unix
        \list
        \o GCC 3.4 and above
        \endlist
    \endlist

    \target ADD_PCH
    \section1 Adding Precompiled Headers to Your Project

    \target PCH_CONTENTS
    \section2 Contents of the Precompiled Header File

    The precompiled header must contain code which is \e stable
    and \e static throughout your project. A typical PCH might look
    like this:

    \section3 Example: \c stable.h

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 104

    Note that a precompiled header file needs to separate C includes from
    C++ includes, since the precompiled header file for C files may not
    contain C++ code.

    \target PROJECT_OPTIONS
    \section2 Project Options

    To make your project use PCH, you only need to define the
    \c PRECOMPILED_HEADER variable in your project file:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 105

    \c qmake will handle the rest, to ensure the creation and use of the
    precompiled header file. You do not need to include the precompiled
    header file in \c HEADERS, as \c qmake will do this if the configuration
    supports PCH.

    All platforms that support precompiled headers have the configuration
    option \c precompile_header set. Using this option, you may trigger
    conditional blocks in your project file to add settings when using PCH.
    For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 106

    \section1 Notes on Possible Issues

    On some platforms, the file name suffix for precompiled header files is
    the same as that for other object files. For example, the following
    declarations may cause two different object files with the same name to
    be generated:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 107

    To avoid potential conflicts like these, it is good practice to ensure
    that header files that will be precompiled are given distinctive names.

    \target EXAMPLE_PROJECT
    \section1 Example Project

    You can find the following source code in the
    \c{examples/qmake/precompile} directory in the Qt distribution:

    \section2 \c mydialog.ui

    \quotefromfile examples/qmake/precompile/mydialog.ui
    \printuntil

    \section2 \c stable.h

    \snippet examples/qmake/precompile/stable.h 0

    \section2 \c myobject.h

    \snippet examples/qmake/precompile/myobject.h 0

    \section2 \c myobject.cpp

    \snippet examples/qmake/precompile/myobject.cpp 0

    \section2 \c util.cpp

    \snippet examples/qmake/precompile/util.cpp 0

    \section2 \c main.cpp

    \snippet examples/qmake/precompile/main.cpp 0

    \section2 \c precompile.pro

    \snippet examples/qmake/precompile/precompile.pro 0
*/

/*!
    \page qmake-tutorial.html
    \title qmake Tutorial
    \contentspage {qmake Manual}{Contents}
    \previouspage qmake Manual
    \nextpage qmake Common Projects

    This tutorial teaches you how to use \c qmake.  We recommend that
    you read the \c qmake user guide after completing this tutorial.

    \section1 Starting off Simple

    Let's assume that you have just finished a basic implementation of
    your application, and you have created the following files:

    \list
    \o hello.cpp
    \o hello.h
    \o main.cpp
    \endlist

    You will find these files in the \c{examples/qmake/tutorial} directory
    of the Qt distribution. The only other thing you know about the setup of
    the application is that it's written in Qt.  First, using your favorite
    plain text editor, create a file called \c hello.pro in
    \c{examples/qmake/tutorial}. The first thing you need to do is add the
    lines that tell \c qmake about the source and header files that are part
    of your development project.

    We'll add the source files to the project file first.  To do this you
    need to use the \l{qmake Variable Reference#SOURCES}{SOURCES} variable.
    Just start a new line with \c {SOURCES +=} and put hello.cpp after it.
    You should have something like this:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 108

    We repeat this for each source file in the project, until we end up
    with the following:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 109

    If you prefer to use a Make-like syntax, with all the files listed in
    one go you can use the newline escaping like this:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 110

    Now that the source files are listed in the project file, the header
    files must be added. These are added in exactly the same way as source
    files, except that the variable name we use is
    \l{qmake Variable Reference#HEADERS}{HEADERS}.

    Once you have done this, your project file should look something like
    this:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 111

    The target name is set automatically; it is the same as the project
    file, but with the suffix appropriate to the platform. For example, if
    the project file is called \c hello.pro, the target will be \c hello.exe
    on Windows and \c hello on Unix. If you want to use a different name
    you can set it in the project file:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 112

    The final step is to set the \l{qmake Variable Reference#CONFIG}{CONFIG}
    variable. Since this is a Qt application, we need to put \c qt on the
    \c CONFIG line so that \c qmake will add the relevant libraries to be
    linked against and ensure that build lines for \c moc and \c uic are
    included in the generated Makefile.

    The finished project file should look like this:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 113

    You can now use \c qmake to generate a Makefile for your application.
    On the command line, in your project's directory, type the following:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 114

    Then type \c make or \c nmake depending on the compiler you use.

    For Visual Studio users, \c qmake can also generate \c .dsp or
    \c .vcproj files, for example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 115

    \section1 Making an Application Debuggable

    The release version of an application doesn't contain any debugging
    symbols or other debugging information. During development it is useful
    to produce a debugging version of the application that has the
    relevant information. This is easily achieved by adding \c debug to the
    \c CONFIG variable in the project file.

    For example:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 116

    Use \c qmake as before to generate a Makefile and you will be able to
    obtain useful information about your application when running it in
    a debugging environment.

    \section1 Adding Platform-Specific Source Files

    After a few hours of coding, you might have made a start on the
    platform-specific part of your application, and decided to keep the
    platform-dependent code separate.  So you now have two new files to
    include into your project file: \c hellowin.cpp and \c
    hellounix.cpp.  We can't just add these to the \c SOURCES
    variable since this will put both files in the Makefile. So, what we
    need to do here is to use a scope which will be processed depending on
    which platform \c qmake is run on.

    A simple scope that will add in the platform-dependent file for
    Windows looks like this:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 117

    So if \c qmake is run on Windows, it will add \c hellowin.cpp to the
    list of source files.  If \c qmake is run on any other platform, it
    will simply ignore it. Now all that is left to be done is to create a
    scope for the Unix-specific file.

    When you have done that, your project file should now look
    something like this:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 118

    Use \c qmake as before to generate a Makefile.

    \section1 Stopping qmake If a File Doesn't Exist

    You may not want to create a Makefile if a certain file doesn't exist.
    We can check if a file exists by using the exists() function.  We can
    stop \c qmake from processing by using the error() function.  This
    works in the same way as scopes do.  Simply replace the scope condition
    with the function. A check for a \c main.cpp file looks like this:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 119

    The \c{!} symbol is used to negate the test; i.e. \c{exists( main.cpp )}
    is true if the file exists, and \c{!exists( main.cpp )} is true if the
    file doesn't exist.

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 120

    Use \c qmake as before to generate a makefile.  If you rename \c
    main.cpp temporarily, you will see the message and \c qmake will stop
    processing.

    \section1 Checking for More than One Condition

    Suppose you use Windows and you want to be able to see statement
    output with qDebug() when you run your application on the command line.
    Unless you build your application with the appropriate console setting,
    you won't see the output. We can easily put \c console on the \c CONFIG
    line so that on Windows the makefile will have this setting. However,
    let's say that we only want to add the \c CONFIG line if we are running
    on Windows \e and when \c debug is already on the \c CONFIG line.
    This requires using two nested scopes; just create one scope, then create
    the other inside it. Put the settings to be processed inside the last
    scope, like this:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 121

    Nested scopes can be joined together using colons, so the final
    project file looks like this:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 122

    That's it! You have now completed the tutorial for \c qmake, and are
    ready to write project files for your development projects.
*/

/*!
    \page qmake-common-projects.html
    \title qmake Common Projects
    \contentspage {qmake Manual}{Contents}
    \previouspage qmake Tutorial
    \nextpage Using qmake

    This chapter describes how to set up \c qmake project files for three
    common project types that are based on Qt. Although all kinds of
    projects use many of the same variables, each of them use project-specific
    variables to customize output files.

    Platform-specific variables are not described here; we refer the reader to
    the \l{Deploying Qt Applications} document for information on issues such as
    \l{Deploying an Application on Mac OS X#Architecture Dependencies}{building
    universal binaries for Mac OS X} and
    \l{Deploying an Application on Windows#Visual Studio 2005 Onwards}
    {handling Visual Studio manifest files}.

    \tableofcontents

    \target Application
    \section1 Building an Application

    \section2 The app Template

    The \c app template tells \c qmake to generate a Makefile that will build
    an application. With this template, the type of application can be specified
    by adding one of the following options to the \c CONFIG variable definition:

    \table
    \header \o Option  \o Description
    \row    \o windows \o The application is a Windows GUI application.
    \row    \o console \o \c app template only: the application is a Windows console
                       application.
    \endtable

    When using this template the following \c qmake system variables are recognized.
    You should use these in your .pro file to specify information about your
    application.

    \list
    \o HEADERS - A list of all the header files for the application.
    \o SOURCES - A list of all the source files for the application.
    \o FORMS - A list of all the .ui files (created using \c{Qt Designer})
    for the application.
    \o LEXSOURCES - A list of all the lex source files for the application.
    \o YACCSOURCES - A list of all the yacc source files for the application.
    \o TARGET - Name of the executable for the application. This defaults
    to the name of the project file. (The extension, if any, is added
    automatically).
    \o DESTDIR - The directory in which the target executable is placed.
    \o DEFINES - A list of any additional pre-processor defines needed for the application.
    \o INCLUDEPATH - A list of any additional include paths needed for the application.
    \o DEPENDPATH - The dependency search path for the application.
    \o VPATH - The search path to find supplied files.
    \o DEF_FILE - Windows only: A .def file to be linked against for the application.
    \o RC_FILE - Windows only: A resource file for the application.
    \o RES_FILE - Windows only: A resource file to be linked against for the application.
    \endlist

    You only need to use the system variables that you have values for,
    for instance, if you don't have any extra INCLUDEPATHs then you don't
    need to specify any, \c qmake will add in the default ones needed.
    For instance, an example project file might look like this:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 123

    For items that are single valued, e.g. the template or the destination
    directory, we use "="; but for multi-valued items we use "+=" to \e
    add to the existing items of that type. Using "=" replaces the item's
    value with the new value, for example if we wrote \c{DEFINES=QT_DLL},
    all other definitions would be deleted.

    \target Library
    \section1 Building a Library

    \section2 The lib Template

    The \c lib template tells \c qmake to generate a Makefile that will
    build a library.  When using this template, in addition to the system variables
    mentioned above for the \c app template the \c VERSION variable is
    supported.  You should use these in your .pro file to specify
    information about the library.

    When using the \c lib template, the following options can be added to the
    \c CONFIG variable to determine the type of library that is built:

    \table
    \header \o Option    \o Description
    \row    \o dll       \o The library is a shared library (dll).
    \row    \o staticlib \o The library is a static library.
    \row    \o plugin    \o The library is a plugin; this also enables the dll option.
    \endtable

    The following option can also be defined to provide additional information about
    the library.

    \list
    \o VERSION - The version number of the target library, for example, 2.3.1.
    \endlist

    The target file name for the library is platform-dependent. For example, on
    X11 and Mac OS X, the library name will be prefixed by \c lib; on Windows,
    no prefix is added to the file name.

    \target Plugin
    \section1 Building a Plugin

    Plugins are built using the \c lib template, as described in the previous
    section. This tells \c qmake to generate a Makefile for the project that will
    build a plugin in a suitable form for each platform, usually in the form of a
    library. As with ordinary libraries, the \c VERSION variable is used to specify
    information about the plugin.

    \list
    \o VERSION - The version number of the target library, for example, 2.3.1.
    \endlist

    \section2 Building a Qt Designer Plugin

    \QD plugins are built using a specific set of configuration settings that
    depend on the way Qt was configured for your system. For convenience, these
    settings can be enabled by adding \c designer to the project's \c CONFIG
    variable. For example:

    \snippet examples/designer/worldtimeclockplugin/worldtimeclockplugin.pro 0

    See the \l{Qt Examples#Qt Designer}{Qt Designer examples} for more
    examples of plugin-based projects.

    \section1 Building and Installing in Debug and Release Modes

    Sometimes, it is necessary to build a project in both debug and release
    modes. Although the \c CONFIG variable can hold both \c debug and \c release
    options, the \c debug option overrides the \c release option.

    \section2 Building in Both Modes

    To enable a project to be built in both modes, you must add the
    \c debug_and_release option to your project's \c CONFIG definition:

    \snippet doc/src/snippets/qmake/debug_and_release.pro 0
    \snippet doc/src/snippets/qmake/debug_and_release.pro 1

    The scope in the above snippet modifies the build target in each mode to
    ensure that the resulting targets have different names. Providing different
    names for targets ensures that one will not overwrite the other.

    When \c qmake processes the project file, it will generate a Makefile rule
    to allow the project to be built in both modes. This can be invoked in the
    following way:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 124

    The \c build_all option can be added to the \c CONFIG variable in the
    project file to ensure that the project is built in both modes by default:

    \snippet doc/src/snippets/qmake/debug_and_release.pro 2

    This allows the Makefile to be processed using the default rule:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 125

    \section2 Installing in Both Modes

    The \c build_all option also ensures that both versions of the target
    will be installed when the installation rule is invoked:

    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 126

    It is possible to customize the names of the build targets depending on
    the target platform. For example, a library or plugin may be named using a
    different convention on Windows to the one used on Unix platforms:

    \omit
    Note: This was originally used in the customwidgetplugin.pro file, but is
    no longer needed there.
    \endomit
    \snippet doc/src/snippets/code/doc_src_qmake-manual.qdoc 127

    The default behavior in the above snippet is to modify the name used for
    the build target when building in debug mode. An \c else clause could be
    added to the scope to do the same for release mode; left as it is, the
    target name remains unmodified.
*/