c-pch.c   [plain text]

/* Precompiled header implementation for the C languages.
   Copyright (C) 2000, 2002 Free Software Foundation, Inc.

This file is part of GNU CC.

GNU CC 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, or (at your option)
any later version.

GNU CC 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 GNU CC; see the file COPYING.  If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

#include "config.h"
#include "system.h"
#include "cpplib.h"
#include "tree.h"
#include "flags.h"
#include "c-common.h"
#include "output.h"
#include "toplev.h"
#include "debug.h"
#include "c-pragma.h"
#include "ggc.h"
#include "langhooks.h"
#include "hosthooks.h"


/* APPLE LOCAL BEGIN pch distcc mrs */
#include "flags.h"
#include "cpphash.h"
/* APPLE LOCAL END pch distcc mrs */

/* APPLE LOCAL indexing dpatel */
#include "genindex.h"

struct c_pch_validity
{
  unsigned char debug_info_type;
};

struct c_pch_header 
{
  unsigned long asm_size;
};

#define IDENT_LENGTH 8

static FILE *pch_outfile;

extern char *asm_file_name;
static off_t asm_file_startpos;

static const char * get_ident PARAMS((void));

/* Compute an appropriate 8-byte magic number for the PCH file, so that
   utilities like file(1) can identify it, and so that GCC can quickly
   ignore non-PCH files and PCH files that are of a completely different
   format.  */

static const char *
get_ident()
{
  static char result[IDENT_LENGTH];
  static const char template[IDENT_LENGTH] = "gpch.011";
  
  memcpy (result, template, IDENT_LENGTH);
  if (c_language == clk_c)
    result[4] = flag_objc ? 'o' : 'C';
  else if (c_language == clk_cplusplus)
    result[4] = flag_objc ? 'O' : '+';
  else
    abort ();
  return result;
}

/* Prepare to write a PCH file.  This is called at the start of 
   compilation.  */

void
pch_init ()
{
  FILE *f;
  struct c_pch_validity v;
  
  if (! pch_file)
    return;
  
  f = fopen (pch_file, "w+b");
  if (f == NULL)
    fatal_io_error ("can't open %s", pch_file);
  pch_outfile = f;
  
  v.debug_info_type = write_symbols;
  if (fwrite (get_ident(), IDENT_LENGTH, 1, f) != 1
      || fwrite (&v, sizeof (v), 1, f) != 1)
    fatal_io_error ("can't write to %s", pch_file);

  /* We need to be able to re-read the output.  */
  /* The driver always provides a valid -o option.  */
  if (asm_file_name == NULL
      || strcmp (asm_file_name, "-") == 0)
    fatal_error ("`%s' is not a valid output file", asm_file_name);
  
  asm_file_startpos = ftell (asm_out_file);
  
  /* Let the debugging format deal with the PCHness.  */
  (*debug_hooks->handle_pch) (0);
  
  cpp_save_state (parse_in, f);
}

/* Write the PCH file.  This is called at the end of a compilation which
   will produce a PCH file.  */

void
c_common_write_pch ()
{
  char *buf;
  off_t asm_file_end;
  off_t written;
  struct c_pch_header h;

  (*debug_hooks->handle_pch) (1);

  cpp_write_pch_deps (parse_in, pch_outfile);

  asm_file_end = ftello (asm_out_file);
  h.asm_size = asm_file_end - asm_file_startpos;
  
  if (fwrite (&h, sizeof (h), 1, pch_outfile) != 1)
    fatal_io_error ("can't write %s", pch_file);
  
  buf = xmalloc (16384);
  fflush (asm_out_file);

  if (fseeko (asm_out_file, asm_file_startpos, SEEK_SET) != 0)
    fatal_io_error ("can't seek in %s", asm_file_name);

  for (written = asm_file_startpos; written < asm_file_end; )
    {
      off_t size = asm_file_end - written;
      if (size > 16384)
	size = 16384;
      if (fread (buf, size, 1, asm_out_file) != 1)
	fatal_io_error ("can't read %s", asm_file_name);
      if (fwrite (buf, size, 1, pch_outfile) != 1)
	fatal_io_error ("can't write %s", pch_file);
      written += size;
    }
  free (buf);

  gt_pch_save (pch_outfile);
  cpp_write_pch_state (parse_in, pch_outfile);

  fclose (pch_outfile);
}

/* Check the PCH file called NAME, open on FD, to see if it can be used
   in this compilation.  */

int
c_common_valid_pch (pfile, name, fd)
     cpp_reader *pfile;
     const char *name;
     int fd;
{
  int sizeread;
  int result;
  char ident[IDENT_LENGTH];
  const char *pch_ident;
  struct c_pch_validity v;

  /* Perform a quick test of whether this is a valid
     precompiled header for the current language.  */

  sizeread = read (fd, ident, IDENT_LENGTH);
  if (sizeread == -1)
    {
      fatal_io_error ("can't read %s", name);
      return 2;
    }
  else if (sizeread != IDENT_LENGTH)
    return 2;
  
  pch_ident = get_ident();
  if (memcmp (ident, pch_ident, IDENT_LENGTH) != 0)
    {
      /* APPLE LOCAL Symbol Separtion */
      if (cpp_get_options (pfile)->warn_invalid_pch 
	  || cpp_get_options (pfile)->warn_invalid_sr)
	{
	  if (memcmp (ident, pch_ident, 5) == 0)
	    /* It's a PCH, for the right language, but has the wrong version.
	     */
	    cpp_error (pfile, DL_WARNING, 
		       "%s: not compatible with this GCC version", name);
	  else if (memcmp (ident, pch_ident, 4) == 0)
	    /* It's a PCH for the wrong language.  */
	    cpp_error (pfile, DL_WARNING, "%s: not for %s", name,
		       lang_hooks.name);
	  else 
	    /* Not any kind of PCH.  */
	    cpp_error (pfile, DL_WARNING, "%s: not a PCH file", name);
	}
      return 2;
    }

  if (read (fd, &v, sizeof (v)) != sizeof (v))
    {
      fatal_io_error ("can't read %s", name);
      return 2;
    }

  /* The allowable debug info combinations are that either the PCH file
     was built with the same as is being used now, or the PCH file was
     built for some kind of debug info but now none is in use.  */
  if (v.debug_info_type != write_symbols
      && write_symbols != NO_DEBUG)
    {
      if (cpp_get_options (pfile)->warn_invalid_pch)
	cpp_error (pfile, DL_WARNING, 
		   "%s: created with -g%s, but used with -g%s", name,
		   debug_type_names[v.debug_info_type],
		   debug_type_names[write_symbols]);
      return 2;
    }

  /* Check the preprocessor macros are the same as when the PCH was
     generated.  */
  
  result = cpp_valid_state (pfile, name, fd);
  if (result == -1)
    return 2;
  else
    return result == 0;
}

/* Load in the PCH file NAME, open on FD.  It was originally searched for
   by ORIG_NAME.  */

void
c_common_read_pch (pfile, name, fd, orig_name)
     cpp_reader *pfile;
     const char *name;
     int fd;
     const char *orig_name ATTRIBUTE_UNUSED;
{
  FILE *f;
  struct c_pch_header h;
  char *buf;
  unsigned long written;
  struct save_macro_data *smd;
  
  /* APPLE LOCAL begin indexing dpatel */
  /* Disable generating indexing information for symbols from PCH. */
  if (flag_gen_index_original)
    flag_gen_index = 0;
  /* APPLE LOCAL end indexing dpatel */

  /* APPLE LOCAL BEGIN pch distcc mrs */
  if (flag_pch_preprocess
      && flag_preprocess_only)
    {
      fprintf (pfile->print.outf, "#include_pch \"%s\"\n", name);
      pfile->print.line++;
      pfile->print.printed = 0;
    }
  /* APPLE LOCAL END pch distcc mrs */

  f = fdopen (fd, "rb");
  if (f == NULL)
    {
      cpp_errno (pfile, DL_ERROR, "calling fdopen");
      return;
    }

  cpp_get_callbacks (parse_in)->valid_pch = NULL;

  if (fread (&h, sizeof (h), 1, f) != 1)
    {
      cpp_errno (pfile, DL_ERROR, "reading");
      return;
    }

  buf = xmalloc (16384);
  for (written = 0; written < h.asm_size; )
    {
      off_t size = h.asm_size - written;
      if (size > 16384)
	size = 16384;
      /* APPLE LOCAL BEGIN pch distcc mrs */
      if (fread (buf, size, 1, f) != 1)
	cpp_errno (pfile, DL_ERROR, "reading");	
      else if (!flag_preprocess_only
	       && fwrite (buf, size, 1, asm_out_file) != 1)
	cpp_errno (pfile, DL_ERROR, "writing");
      /* APPLE LOCAL END pch distcc mrs */
      written += size;
    }
  free (buf);

  cpp_prepare_state (pfile, &smd);

  gt_pch_restore (f);

  if (cpp_read_state (pfile, name, f, smd) != 0)
    return;

  fclose (f);

  /* APPLE LOCAL begin indexing dpatel */
  /* Enable generating indexing information for symbols from PCH. */
  if (flag_gen_index_original)
    flag_gen_index = 1;
  /* APPLE LOCAL end indexing dpatel */
}

/* Indicate that no more PCH files should be read.  */

void
c_common_no_more_pch (void)
{
  if (cpp_get_callbacks (parse_in)->valid_pch)
    {
      cpp_get_callbacks (parse_in)->valid_pch = NULL;
      host_hooks.gt_pch_use_address (NULL, 0);
    }
}