/* $Id: kLdrHlp.c 2828 2006-10-22 18:21:04Z bird $ */
/** @file
 *
 * kLdr - The Dynamic Loader, Helper Functions.
 *
 * Copyright (c) 2006 knut st. osmundsen <bird-kbuild-src@anduin.net>
 *
 *
 * This file is part of kLdr.
 *
 * kLdr is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * kLdr is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with kLdr; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */


/*******************************************************************************
*   Header Files                                                               *
*******************************************************************************/
#ifdef __OS2__
# define INCL_BASE
# define INCL_ERRORS
# include <os2.h>
#elif defined(__WIN__)
# include <Windows.h>
#else
# error "port me"
#endif

#include <kLdr.h>
#include "kLdrHlp.h"


/**
 * Get an environment variable.
 *
 * @returns 0 on success, on failure an OS specific status code is returned.
 * @param   pszVar      The variable name.
 * @param   pszVal      Where to store the value. NULL is allowed if *pcchVal is 0.
 * @param   pcchVal     On input the size of the buffer pointed to by pszVal.
 *                      On output this contains the string length on success, while on
 *                      failure (including buffer overflow) the require buffer size.
 *                      If the variable wasn't found, it's set to 0.
 */
int     kldrHlpGetEnv(const char *pszVar, char *pszVal, size_t *pcchVal)
{
#ifdef __OS2__
    PSZ pszValue = NULL;
    int rc = DosScanEnv((PCSZ)pszVar, &pszValue);
    if (!rc)
    {
        size_t cch = kLdrHlpStrLen(pszValue);
        if (pszVal)
        {
            if (*pcchVal > cch)
            {
                kLdrHlpMemCopy(pszVal, pszValue, cch + 1);
                *pcchVal = cch;
            }
            else if (*pcchVal)
            {
                kLdrHlpMemCopy(pszVal, pszValue, *pcchVal);
                pszVal[*pcchVal - 1] = '\0';
                rc = ERROR_BUFFER_OVERFLOW;
                *pcchVal = cch + 1;
            }
        }
        else
        {
            rc = ERROR_BUFFER_OVERFLOW;
            *pcchVal = cch + 1;
        }
    }
    else
    {
        if (pszVal)
            *pszVal = '\0';
        *pcchVal = 0;
    }

    return rc;

#elif defined(__WIN__)
    DWORD cch;
    SetLastError(0);
    cch = GetEnvironmentVariable(pszVar, pszVal, *pcchVal);
    if (cch)
    {
        *pcchVal = cch;
        return 0;
    }
    if (!GetLastError() == ERROR_ENVVAR_NOT_FOUND)
    {
        *pcchVal = 0;
        return ERROR_ENVVAR_NOT_FOUND;
    }
    *pcchVal = cch;
    return ERROR_BUFFER_OVERFLOW;

#else
# error "Port me"
#endif
}


/**
 * Terminate the process.
 *
 * @param   rc      The exit status.
 */
void    kldrHlpExit(int rc)
{
    for (;;)
    {
#ifdef __OS2__
        DosExit(EXIT_PROCESS, rc);

#elif defined(__WIN__)
        TerminateProcess(GetCurrentProcess(), rc);

#else
# error "Port me"
#endif
        kldrHlpAssert(!"Impossible");
    }
}

/** Internal worker for kldrHlpAssertMsg. */
static void int2dec(char *pszLine, unsigned iLine)
{
    do
    {
        *pszLine = (iLine % 10) + '0';
        iLine /= 10;
    } while (iLine);
    *pszLine++ = '\0';
}


/**
 * Internal worker for the kLdrHlpAssert() macro.
 *
 * @param   pszExpr         The assert expression.
 * @param   pszFile         The filename.
 * @param   iLine           The line number.
 * @param   pszFunction     The function name.
 */
void    kldrHlpAssertMsg(const char *pszExpr, const char *pszFile, unsigned iLine, const char *pszFunction)
{
#ifdef __OS2__
    static const char   s_szMsg1[] = "\r\n!!!kLdr Assertion Failed!!!\n\rExpression: ";
    static const char   s_szMsg2[] = "\r\nAt: ";
    static const char   s_szMsg3[] = "\r\n";
    ULONG               cbWritten;
    char                szLine[16];

    DosWrite((HFILE)2, s_szMsg1, sizeof(s_szMsg1) - 1, &cbWritten);
    DosWrite((HFILE)2, pszExpr, kLdrHlpStrLen(pszExpr), &cbWritten);
    DosWrite((HFILE)2, s_szMsg2, sizeof(s_szMsg2) - 1, &cbWritten);
    DosWrite((HFILE)2, pszFile, kLdrHlpStrLen(pszFile), &cbWritten);
    DosWrite((HFILE)2, "(", sizeof("(") - 1, &cbWritten);
    int2dec(szLine, iLine);
    DosWrite((HFILE)2, szLine, kLdrHlpStrLen(szLine), &cbWritten);
    DosWrite((HFILE)2, ") ", sizeof(") ") - 1, &cbWritten);
    DosWrite((HFILE)2, pszFunction, kLdrHlpStrLen(pszFunction), &cbWritten);
    DosWrite((HFILE)2, s_szMsg3, sizeof(s_szMsg3) - 1, &cbWritten);

#elif defined(__WIN__)
    static const char   s_szMsg1[] = "\r\n!!!kLdr Assertion Failed!!!\n\rExpression: ";
    static const char   s_szMsg2[] = "\r\nAt: ";
    static const char   s_szMsg3[] = "\r\n";
    DWORD               cbWritten;
    char                szLine[16];
    const HANDLE        hStdErr = (HANDLE)STD_ERROR_HANDLE;

    WriteFile(hStdErr, s_szMsg1, sizeof(s_szMsg1) - 1, &cbWritten, NULL);
    WriteFile(hStdErr, pszExpr, kLdrHlpStrLen(pszExpr), &cbWritten, NULL);
    WriteFile(hStdErr, s_szMsg2, sizeof(s_szMsg2) - 1, &cbWritten, NULL);
    WriteFile(hStdErr, pszFile, kLdrHlpStrLen(pszFile), &cbWritten, NULL);
    WriteFile(hStdErr, "(", sizeof("(") - 1, &cbWritten, NULL);
    int2dec(szLine, iLine);
    WriteFile(hStdErr, szLine, kLdrHlpStrLen(szLine), &cbWritten, NULL);
    WriteFile(hStdErr, ") ", sizeof(") ") - 1, &cbWritten, NULL);
    WriteFile(hStdErr, pszFunction, kLdrHlpStrLen(pszFunction), &cbWritten, NULL);
    WriteFile(hStdErr, s_szMsg3, sizeof(s_szMsg3) - 1, &cbWritten, NULL);

#else
# error "Port me"
#endif
}