/* $Id: kLdrHlp.c 2944 2007-01-13 15:55:40Z bird $ */
/** @file
 *
 * kLdr - The Dynamic Loader, Misc 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.
 * @returns KLDR_ERR_BUFFER_OVERFLOW on if the buffer is too small.
 * @returns KLDR_ERR_SYMBOL_NOT_FOUND if not found. (Yeah, abusing the status code, but it's only internally...)
 * @returns OS specfic status code on other error.
 * @param   pszVar      The variable name.
 * @param   pszVal      Where to store the value.
 * @param   cchVal      The size of the buffer pointed to by pszVal.
 */
int     kldrHlpGetEnv(const char *pszVar, char *pszVal, size_t cchVal)
{
#ifdef __OS2__
    PSZ pszValue = NULL;
    int rc;

    *pszVal = '\0';
    rc = DosScanEnv((PCSZ)pszVar, &pszValue);
    if (!rc)
    {
        size_t cch = kLdrHlpStrLen((const char *)pszValue);
        if (cchVal > cch)
            kLdrHlpMemCopy(pszVal, pszValue, cch + 1);
        else
            rc = KLDR_ERR_BUFFER_OVERFLOW;
    }
    else
        rc = KLDR_ERR_SYMBOL_NOT_FOUND;
    return rc;

#elif defined(__WIN__)
    DWORD cch;

    SetLastError(0);
    cch = GetEnvironmentVariable(pszVar, pszVal, cchVal);
    if (cch > 0 && cch < cchVal)
        return 0;

    *pszVal = '\0';
    if (cch >= cchVal)
        return KLDR_ERR_BUFFER_OVERFLOW;
    if (GetLastError() == ERROR_ENVVAR_NOT_FOUND)
        return KLDR_ERR_SYMBOL_NOT_FOUND;
    return GetLastError();

#else
# error "Port me"
#endif
}


/**
 * Gets an environment variable and converts it to a size_t.
 *
 * @returns 0 and *pcb on success.
 * @returns On failure see kldrHlpGetEnv.
 * @param   pszVar  The name of the variable.
 * @param   pcb     Where to put the value.
 */
int     kldrHlpGetEnvUZ(const char *pszVar, size_t *pcb)
{
    size_t      cb;
    unsigned    uBase;
    char        szVal[64];
    size_t      cchVal = sizeof(szVal);
    const char *psz;
    int         rc;

    *pcb = 0;
    rc = kldrHlpGetEnv(pszVar, szVal, cchVal);
    if (rc)
        return rc;

    /* figure out the base. */
    uBase = 10;
    psz = szVal;
    if (    *psz == '0'
        &&  (psz[1] == 'x' || psz[1] == 'X'))
    {
        uBase = 16;
        psz += 2;
    }

    /* convert it up to the first unknown char. */
    cb = 0;
    for(;;)
    {
        const char ch = *psz;
        unsigned uDigit;
        if (!ch)
            break;
        else if (ch >= '0' && ch <= '9')
            uDigit = ch - '0';
        else if (ch >= 'a' && ch <= 'z')
            uDigit = ch - 'a' + 10;
        else if (ch >= 'A' && ch <= 'Z')
            uDigit = ch - 'A' + 10;
        else
            break;
        if (uDigit >= uBase)
            break;

        /* add the digit */
        cb *= uBase;
        cb += uDigit;

        psz++;
    }

    /* check for unit */
    if (*psz == 'm' || *psz == 'M')
        cb *= 1024*1024;
    else if (*psz == 'k' ||*psz == 'K')
        cb *= 1024;
    else if (*psz == 'g' || *psz == 'G')
        cb *= 1024*1024*1024;

    *pcb = cb;
    return 0;
}


/**
 * 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");
    }
}


/**
 * Sleep for a number of milliseconds.
 * @param   cMillies    Number of milliseconds to sleep.
 */
void kldrHlpSleep(unsigned cMillies)
{
#ifdef __OS2__
    DosSleep(cMillies);
#elif defined(__WIN__)
    Sleep(cMillies);
#else
    usleep(cMillies * 1000);
#endif
}


/**
 * Writes a assert string with unix lineendings.
 *
 * @param   pszMsg  The string.
 */
static void kldrHlpAssertWrite(const char *pszMsg)
{
#if defined(__OS2__) || defined(__WIN__)
    /*
     * Line by line.
     */
    ULONG       cbWritten;
    const char *pszNl = kLdrHlpStrChr(pszMsg, '\n');
    while (pszNl)
    {
        cbWritten = pszNl - pszMsg;

#ifdef __OS2__
        if (cbWritten)
            DosWrite((HFILE)2, pszMsg, cbWritten, &cbWritten);
        DosWrite((HFILE)2, "\r\n", 2, &cbWritten);
#else /* __WIN32__ */
        if (cbWritten)
            WriteFile((HANDLE)STD_ERROR_HANDLE, pszMsg, cbWritten, &cbWritten, NULL);
        WriteFile((HANDLE)STD_ERROR_HANDLE, "\r\n", 2, &cbWritten, NULL);
#endif

        /* next */
        pszMsg = pszNl + 1;
        pszNl = kLdrHlpStrChr(pszMsg, '\n');
    }

    /*
     * Remaining incomplete line.
     */
    if (*pszMsg)
    {
        cbWritten = kLdrHlpStrLen(pszMsg);
#ifdef __OS2__
        DosWrite((HFILE)2, pszMsg, cbWritten, &cbWritten);
#else /* __WIN32__ */
        WriteFile((HANDLE)STD_ERROR_HANDLE, pszMsg, cbWritten, &cbWritten, NULL);
#endif
    }

#else
# error "port me"
#endif
}


/**
 * 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)
{
    char szLine[16];

    kldrHlpAssertWrite("\n!!!kLdr Assertion Failed!!!\nExpression: ");
    kldrHlpAssertWrite(pszExpr);
    kldrHlpAssertWrite("\nAt: ");
    kldrHlpAssertWrite(pszFile);
    kldrHlpAssertWrite("(");
    kldrHlpAssertWrite(kldrHlpInt2Ascii(szLine, sizeof(szLine), iLine, 10));
    kldrHlpAssertWrite(") ");
    kldrHlpAssertWrite(pszFunction);
    kldrHlpAssertWrite("\n");
}