/*
 * $Id: fixincl.c,v 1.1 1998/03/20 16:19:41 korbb Exp $
 *
 * Install modified versions of certain ANSI-incompatible system header
 * files which are fixed to work correctly with ANSI C and placed in a
 * directory that GNU C will search.
 *
 * See README-fixinc for more information.
 *
 *  fixincl is free software.
 *  
 *  You may 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, or (at your option) any later version.
 *  
 *  fixincl 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 fixincl.  See the file "COPYING".  If not,
 *  write to:  The Free Software Foundation, Inc.,
 *             59 Temple Place - Suite 330,
 *             Boston,  MA  02111-1307, USA.
 */

#include <sys/param.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/stropts.h>
#include <sys/wait.h>
#include <signal.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <stropts.h>
#include <poll.h>
#include <fcntl.h>
#include <ctype.h>

#include "regex.h"
#include "server.h"

#define tSCC static const char
#define tCC  const char
#define tSC  static char

typedef int tSuccess;

#define FAILURE  ((tSuccess)-1)
#define SUCCESS  ((tSuccess) 0)
#define PROBLEM  ((tSuccess) 1)

#define SUCCEEDED( p )     ((p) == SUCCESS)
#define SUCCESSFUL( p )    SUCCEEDED( p )
#define FAILED( p )        ((p) <  SUCCESS)
#define HADGLITCH( p )     ((p) >  SUCCESS)

#define NUL '\0'

typedef enum
  {
    TT_TEST, TT_EGREP, TT_NEGREP
  }
teTestType;

typedef struct test_desc tTestDesc;

struct test_desc
  {
    teTestType type;
    const char *pzTest;
    regex_t *pTestRegex;
  };

typedef enum
  {
    PATCH_SED, PATCH_SHELL
  }
tePatch;

typedef struct patch_desc tPatchDesc;

typedef struct fix_desc tFixDesc;
struct fix_desc
  {
    const char *pzFixName;
    const char *pzFileList;
    regex_t *pListRegex;
    int testCt;
    tTestDesc *pTestDesc;
    const char **papzPatchArgs;
  };

char *pzDestDir = (char *) NULL;
char *pzSrcDir = (char *) NULL;

pid_t chainHead = (pid_t) - 1;

const char zInclQuote[] = "^[ \t]*#[ \t]*include[ \t]*\"[^/]";
regex_t inclQuoteRegex;

char zFileNameBuf[0x8000];

char *loadFile (const char *pzFile);
void process (char *data, const char *dir, const char *file);
void runCompiles (void);

#include "fixincl.x"


int
main (argc, argv)
     int argc;
     char **argv;
{
  static const char zGnuLib[] =
  "This file is part of the GNU C Library";

#ifndef NO_BOGOSITY_LIMITS
  size_t loopCt;
#endif

  char *apzNames[128];
  size_t fileNameCt;

  if (argc != 1)
    {
      if (argc != 2)
	{
	  fputs ("fixincl ERROR:  files specified on command line (not stdin)\n",
		 stderr);
	  exit (EXIT_FAILURE);
	}

      if (strcmp (argv[1], "-v") == 0)
	{
	  fputs ("$Id: fixincl.c,v 1.1 1998/03/20 16:19:41 korbb Exp $\n", stderr);
	  exit (EXIT_SUCCESS);
        }

      freopen (argv[1], "r", stdin);
    }

  pzDestDir = getenv ("DESTDIR");
  if (pzDestDir == (char *) NULL)
    {
      fprintf (stderr, "fixincl ERROR:  %s cannot find destination dir\n"
	       "\t(`DESTDIR' must be an environment variable)\n", *argv);
      exit (EXIT_FAILURE);
    }

  pzSrcDir = getenv ("SRCDIR");
  if (pzSrcDir == (char *) NULL)
    {
      fprintf (stderr, "fixincl ERROR:  %s cannot find source dir\n"
	       "\t(`SRCDIR' must be an environment variable)\n", *argv);
      exit (EXIT_FAILURE);
    }

  runCompiles ();

#ifndef NO_BOGOSITY_LIMITS
  for (;;)
    {
      char *pzBuf;
      pid_t child;

      /*
       *  Only the parent process can read from stdin without
       *  confusing the world.  (How does the child tell the
       *  parent to skip forward?  Pipes and files behave differently.)
       */
      for (fileNameCt = 0, pzBuf = zFileNameBuf;
	   (fileNameCt < 128)
	   && (pzBuf
	       < (zFileNameBuf + sizeof (zFileNameBuf) - MAXPATHLEN));
	)
	{

	  if (fgets (pzBuf, MAXPATHLEN, stdin) == (char *) NULL)
	    break;
	  while (isspace (*pzBuf))
	    pzBuf++;
	  apzNames[fileNameCt++] = pzBuf;
	  pzBuf += strlen (pzBuf);
	  while (isspace (pzBuf[-1]))
	    pzBuf--;
	  *pzBuf++ = '\0';
	}

      if (fileNameCt == 0)
	return EXIT_SUCCESS;

      child = fork ();
      if (child == NULLPROCESS)
	break;

      if (child == NOPROCESS)
	{
	  fprintf (stderr, "Error %d (%s) forking in main\n",
		   errno, strerror (errno));
	  exit (EXIT_FAILURE);
	}

      waitpid (child, (int *) NULL, 0);
    }
#else
#error "NON-BOGUS LIMITS NOT SUPPORTED?!?!"
#endif

  /*
   *  For every file specified in stdandard in
   *  (except as throttled for bogus reasons)...
   */
  for (loopCt = 0; loopCt < fileNameCt; loopCt++)
    {
      char *pzData;
      char *pzFile = apzNames[loopCt];

      if (access (pzFile, R_OK) != 0)
	{
	  int erno = errno;
	  fprintf (stderr, "Cannot access %s from %s\n\terror %d (%s)\n",
		   pzFile, getcwd ((char *) NULL, MAXPATHLEN),
		   erno, strerror (erno));
	}
      else if (pzData = loadFile (pzFile),
	       (pzData != (char *) NULL))
	{

	  if (strstr (pzData, zGnuLib) == (char *) NULL)
	    process (pzData, pzDestDir, pzFile);

	  free ((void *) pzData);
	}
    }

  return EXIT_SUCCESS;
}


char *
loadFile (pzFile)
     const char *pzFile;
{
  char *pzDta;
  size_t fileSize;

  {
    struct stat stbf;
    if (stat (pzFile, &stbf) != 0)
      {
	fprintf (stderr, "error %d (%s) stat-ing %s\n",
		 errno, strerror (errno), pzFile);
	return (char *) NULL;
      }
    fileSize = stbf.st_size;
  }
  if (fileSize == 0)
    return (char *) NULL;

  pzDta = (char *) malloc ((fileSize + 16) & ~0x00F);
  if (pzDta == (char *) NULL)
    {
      fprintf (stderr, "error:  could not malloc %d bytes\n",
	       fileSize);
      exit (EXIT_FAILURE);
    }

  {
    FILE *fp = fopen (pzFile, "r");
    size_t sizeLeft = fileSize;
    char *readPtr = pzDta;

    if (fp == (FILE *) NULL)
      {
	fprintf (stderr, "error %d (%s) opening %s\n", errno,
		 strerror (errno), pzFile);
	free ((void *) pzDta);
	return (char *) NULL;
      }

    do
      {
	size_t sizeRead = fread ((void *) readPtr, 1, sizeLeft, fp);

	if (sizeRead == 0)
	  {
	    if (feof (fp))
	      break;

	    if (ferror (fp))
	      {
		fprintf (stderr, "error %d (%s) reading %s\n", errno,
			 strerror (errno), pzFile);
		free ((void *) pzDta);
		fclose (fp);
		return (char *) NULL;
	      }
	  }

	readPtr += sizeRead;
	sizeLeft -= sizeRead;
      }
    while (sizeLeft != 0);

    *readPtr = '\0';
    fclose (fp);
    return pzDta;
  }
}


void
runCompiles ()
{
  tSCC zBadComp[] = "fixincl ERROR:  cannot compile %s regex for %s\n"
  "\texpr = `%s'\n" "\terror %s\n";
  tFixDesc *pFD = fixDescList;
  int fixCt = FIX_COUNT;
  tTestDesc *pTD;
  int tstCt;
  int reCt = REGEX_COUNT;
  const char *pzErr;
  regex_t *pRegex = (regex_t *) malloc (REGEX_COUNT * sizeof (regex_t));

  if (pRegex == (regex_t *) NULL)
    {
      fprintf (stderr, "fixincl ERROR:  cannot allocate %d bytes for regex\n",
	       REGEX_COUNT * sizeof (regex_t));
      exit (EXIT_FAILURE);
    }

  re_set_syntax (RE_SYNTAX_EGREP);
  pzErr = re_compile_pattern (zInclQuote, strlen (zInclQuote),
			      &inclQuoteRegex);
  if (pzErr != (char *) NULL)
    {
      fprintf (stderr, zBadComp, "quoted include", "runCompiles",
	       zInclQuote, pzErr);
      exit (EXIT_FAILURE);
    }

  /*
   *  FOR every fixup, ...
   */
  for (;;)
    {
      pTD = pFD->pTestDesc;
      tstCt = pFD->testCt;

      /*
       *  FOR every test for the fixup, ...
       */
      while (--tstCt >= 0)
	{
	  switch (pTD->type)
	    {
	    case TT_EGREP:
	    case TT_NEGREP:
	      if (--reCt < 0)
		{
		  fputs ("out of RE's\n", stderr);
		  exit (EXIT_FAILURE);
		}

	      pTD->pTestRegex = pRegex++;
	      pzErr = re_compile_pattern (pTD->pzTest,
					  strlen (pTD->pzTest),
					  pTD->pTestRegex);
	      if (pzErr != (char *) NULL)
		{
		  fprintf (stderr, zBadComp, "select test", pFD->pzFixName,
			   pTD->pzTest, pzErr);
		  exit (EXIT_FAILURE);
		}
	    }
	  pTD++;
	}

      if (--fixCt <= 0)
	break;
      pFD++;
    }
}


FILE *
createFile (pzFile)
     const char *pzFile;
{
  int fd;
  FILE *pf;
  char fname[MAXPATHLEN];

  sprintf (fname, "%s/%s", pzDestDir, pzFile);
  unlink (fname);

  fd = open (fname, O_WRONLY | O_CREAT);

  if ((fd < 0) && (errno == ENOENT))
    {
      char *pzDir = strchr (fname + 1, '/');
      struct stat stbf;

      while (pzDir != (char *) NULL)
	{
	  *pzDir = NUL;
	  if (stat (fname, &stbf) < 0)
	    {
	      mkdir (fname, S_IFDIR | S_IRWXU | S_IRGRP | S_IXGRP
		     | S_IROTH | S_IXOTH);
	    }

	  *pzDir = '/';
	  pzDir = strchr (pzDir + 1, '/');
	}
      fd = open (fname, O_WRONLY | O_CREAT);
    }
  if (fd < 0)
    {
      fprintf (stderr, "Error %d (%s) creating %s\n",
	       errno, strerror (errno), fname);
      exit (EXIT_FAILURE);
    }
  fprintf (stderr, "Fixed:  %s\n", pzFile);
  pf = fdopen (fd, "w");

#ifdef LATER
  {
    static const char zHdr[] =
    "/*\n"
    " *  DO NOT EDIT THIS FILE.\n"
    " *\n"
    " *  It has been auto-edited by fixincludes from /usr/include/%s\n"
    " *  This had to be done to correct non-standard usages in the\n"
    " *  original, manufacturer supplied header file.\n"
    " */\n\n";

    fprintf (pf, zHdr, pzFile);
  }
#endif
  return pf;
}

tSuccess
testTest (pTest)
     tTestDesc *pTest;
{
  char *pzRes;
  tSuccess res = FAILURE;

  static char zCmdBuf[4096];
  tSCC zCmdFmt[] = "if ( test %s ) > /dev/null 2>&1\n"
  "then echo TRUE\n" "else echo FALSE\n" "fi";

  sprintf (zCmdBuf, zCmdFmt, pTest->pzTest);
  pzRes = runShell (zCmdBuf);
  if (*pzRes == 'T')
    res = SUCCESS;
  free ((void *) pzRes);
  return res;
}


tSuccess
egrepTest (pzDta, pTest)
     char *pzDta;
     tTestDesc *pTest;
{
  regmatch_t match;
#ifndef NO_BOGOSITY
  if (pTest->pTestRegex == 0)
    fprintf (stderr, "fixincl ERROR RE not compiled:  `%s'\n", pTest->pzTest);
#endif
  if (regexec (pTest->pTestRegex, pzDta, 1, &match, 0) == 0)
    return SUCCESS;
  return FAILURE;
}



void
extractQuotedFiles (pzDta, pzFile, pMatch)
     char *pzDta;
     const char *pzFile;
     regmatch_t *pMatch;
{
  char *pzDirEnd = strrchr (pzFile, '/');
  char *pzInclQuot = pzDta;

  fprintf (stderr, "Quoted includes in %s\n", pzFile);

  /*
   *  Set "pzFile" to point to the containing subdirectory of the source
   *  If there is none, then it is in our current direcory, ".".
   */
  if (pzDirEnd == (char *) NULL)
    pzFile = ".";
  else
    *pzDirEnd = '\0';

  for (;;)
    {
      pzInclQuot += pMatch->rm_so;

      /*
       *  Skip forward to the included file name
       */
      while (isspace (*pzInclQuot))
	pzInclQuot++;
      while (isspace (*++pzInclQuot));
      pzInclQuot += sizeof ("include") - 1;
      while (*pzInclQuot++ != '"');

      /*
       *  Print the source directory and the subdirectory of the file
       *  in question.
       */
      printf ("%s  %s/", pzSrcDir, pzFile);
      pzDirEnd = pzInclQuot;

      /*
       *  Append to the directory the relative path of the desired file
       */
      while (*pzInclQuot != '"')
	putc (*pzInclQuot++, stdout);

      /*
       *  Now print the destination directory appended with the relative
       *  path of the desired file
       */
      printf ("  %s/%s/", pzDestDir, pzFile);
      while (*pzDirEnd != '"')
	putc (*pzDirEnd++, stdout);

      /*
       *  End of entry
       */
      putc ('\n', stdout);

      /*
       *  Find the next entry
       */
      if (regexec (&inclQuoteRegex, pzInclQuot, 1, pMatch, 0) != 0)
	break;
    }
}


/*
 *  Process the potential fixes for a particular include file
 */
void
process (pzDta, pzDir, pzFile)
     char *pzDta;
     const char *pzDir;
     const char *pzFile;
{
  static char zEnvFile[1024] =
  {"file="};
  tFixDesc *pFD = fixDescList;
  int todoCt = FIX_COUNT;
  tFdPair fdp =
  {-1, -1};

  /*
   *  IF this is the first time through,
   *  THEN put the 'file' environment variable into the environment.
   *       This is used by some of the subject shell scripts and tests.
   */
  if (zEnvFile[5] == NUL)
    putenv (zEnvFile);

  /*
   *  Ghastly as it is, this actually updates the value of the variable:
   *
   *    putenv(3C)             C Library Functions             putenv(3C)
   *
   *    DESCRIPTION
   *         putenv() makes the value of the  environment  variable  name
   *         equal  to value by altering an existing variable or creating
   *         a new one.  In either case, the string pointed to by  string
   *         becomes part of the environment, so altering the string will
   *         change the environment.  string points to a  string  of  the
   *         form  ``name=value.''  The space used by string is no longer
   *         used once a new string-defining name is passed to putenv().
   */
  strcpy (zEnvFile + 5, pzFile);
  chainHead = NOPROCESS;

  /*
   *  For every fix in our fix list, ...
   */
  for (; todoCt > 0; pFD++, todoCt--)
    {
      tTestDesc *pTD;
      int tstCt;
      tSuccess egrepRes;

      /*
       *  IF there is a file name restriction,
       *  THEN ensure the current file name matches one in the pattern
       */
      if (pFD->pzFileList != (char *) NULL)
	{
	  const char *pzFil = pzFile;
	  const char *pzScn = pFD->pzFileList;
	  size_t nmLen;

	  while ((pzFil[0] == '.') && (pzFil[1] == '/'))
	    pzFil += 2;
	  nmLen = strlen (pzFil);

	  for (;;)
	    {
	      pzScn = strstr (pzScn + 1, pzFil);
	      if (pzScn == (char *) NULL)
		goto nextFix;
	      if ((pzScn[-1] == '|') && (pzScn[nmLen] == '|'))
		break;
	    }
	}

      egrepRes = PROBLEM;

      /*
       *  IF there are no tests
       *  THEN we always run the fixup
       */
      for (pTD = pFD->pTestDesc, tstCt = pFD->testCt;
	   tstCt-- > 0;
	   pTD++)
	{
	  switch (pTD->type)
	    {
	    case TT_TEST:
	      /*
	       *  IF *any* of the shell tests fail,
	       *  THEN do not process the fix.
	       */
	      if (!SUCCESSFUL (testTest (pTD)))
		goto nextFix;
	      break;

	    case TT_EGREP:
	      /*
	       *  IF       we have not had a successful egrep test
	       *    *AND*  this test does not pass,
	       *  THEN mark the egrep test as failing.  It starts
	       *       out as a "PROBLEM", meaning that if we do not
	       *       encounter any egrep tests, then we will let it pass.
	       */
	      if ((!SUCCESSFUL (egrepRes))
		  && (!SUCCESSFUL (egrepTest (pzDta, pTD))))

		egrepRes = FAILURE;

	      break;

	    case TT_NEGREP:
	      /*
	       *  IF *any* of the negative egrep tests fail,
	       *  THEN do not process the fix.
	       */
	      if (SUCCESSFUL (egrepTest (pzDta, pTD)))
		goto nextFix;
	      break;
	    }
	}

      /*
       *  IF there were no egrep tests *OR* at least one passed, ...
       */
      if (!FAILED (egrepRes))
	{
	  fprintf (stderr, "Applying %-32s to %s\n",
		   pFD->pzFixName, pzFile);

	  if (fdp.readFd == -1)
	    {
	      fdp.readFd = open (pzFile, O_RDONLY);
	      if (fdp.readFd < 0)
		{
		  fprintf (stderr, "Error %d (%s) opening %s\n", errno,
			   strerror (errno), pzFile);
		  exit (EXIT_FAILURE);
		}
	    }

	  for (;;)
	    {
	      int newFd = chainOpen (fdp.readFd,
				     (tpChar *) pFD->papzPatchArgs,
				     (chainHead == -1)
				     ? &chainHead : (pid_t *) NULL);
	      if (newFd != -1)
		{
		  fdp.readFd = newFd;
		  break;
		}

	      fprintf (stderr, "Error %d (%s) starting filter process "
		       "for %s\n", errno, strerror (errno),
		       pFD->pzFixName);

	      if (errno != EAGAIN)
		exit (EXIT_FAILURE);
	      sleep (1);
	    }
	}

    nextFix:;
    }

  /*
   *  IF after all the tests we did not start any patch programs,
   *  THEN quit now.
   */
  if (fdp.readFd < 0)
    return;

  {
    FILE *inFp = fdopen (fdp.readFd, "r");
    FILE *oFp = (FILE *) NULL;
    char *pzCmp = pzDta;

    for (;;)
      {
	int ch;

	ch = getc (inFp);
	if (ch == EOF)
	  break;

	if (oFp != (FILE *) NULL)
	  putc (ch, oFp);

	else if (ch != *pzCmp)
	  {
	    oFp = createFile (pzFile);
	    if (pzCmp != pzDta)
	      {
		char c = *pzCmp;
		*pzCmp = NUL;
		fputs (pzDta, oFp);
		*pzCmp = c;
	      }
	    putc (ch, oFp);

	  }
	else
	  pzCmp++;
      }

    if (oFp != (FILE *) NULL)
      {
	regmatch_t match;

	fchmod (fileno (oFp), S_IRUSR | S_IRGRP | S_IROTH);
	fclose (oFp);
	if (regexec (&inclQuoteRegex, pzDta, 1, &match, 0) == 0)
	  extractQuotedFiles (pzDta, pzFile, &match);
      }

    fclose (inFp);
  }

  close (fdp.readFd);
}