/* Precompiled header implementation for the C languages.
- Copyright (C) 2000, 2002 Free Software Foundation, Inc.
+ Copyright (C) 2000, 2002, 2003, 2004, 2005, 2007, 2008, 2009
+ Free Software Foundation, Inc.
-This file is part of GNU CC.
+This file is part of GCC.
-GNU CC is free software; you can redistribute it and/or modify
+GCC 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)
+the Free Software Foundation; either version 3, or (at your option)
any later version.
-GNU CC is distributed in the hope that it will be useful,
+GCC 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. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
+#include "version.h"
#include "cpplib.h"
#include "tree.h"
+#include "flags.h"
#include "c-common.h"
#include "output.h"
#include "toplev.h"
#include "c-pragma.h"
#include "ggc.h"
#include "langhooks.h"
+#include "hosthooks.h"
+#include "target.h"
+#include "opts.h"
-struct c_pch_header
+/* This is a list of flag variables that must match exactly, and their
+ names for the error message. The possible values for *flag_var must
+ fit in a 'signed char'. */
+
+static const struct c_pch_matching
+{
+ int *flag_var;
+ const char *flag_name;
+} pch_matching[] = {
+ { &flag_exceptions, "-fexceptions" },
+};
+
+enum {
+ MATCH_SIZE = ARRAY_SIZE (pch_matching)
+};
+
+/* The value of the checksum in the dummy compiler that is actually
+ checksummed. That compiler should never be run. */
+static const char no_checksum[16] = { 0 };
+
+/* Information about flags and suchlike that affect PCH validity.
+
+ Before this structure is read, both an initial 8-character identification
+ string, and a 16-byte checksum, have been read and validated. */
+
+struct c_pch_validity
+{
+ unsigned char debug_info_type;
+ signed char match[MATCH_SIZE];
+ void (*pch_init) (void);
+ size_t target_data_length;
+};
+
+struct c_pch_header
{
unsigned long asm_size;
};
#define IDENT_LENGTH 8
+/* The file we'll be writing the PCH to. */
static FILE *pch_outfile;
-extern char *asm_file_name;
+/* The position in the assembler output file when pch_init was called. */
static long asm_file_startpos;
-static const char * get_ident PARAMS((void));
+static const char *get_ident (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()
+get_ident (void)
{
static char result[IDENT_LENGTH];
- static const char template[IDENT_LENGTH] = "gpch.010";
-
- 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 ();
+ static const char templ[] = "gpch.013";
+ static const char c_language_chars[] = "Co+O";
+
+ memcpy (result, templ, IDENT_LENGTH);
+ result[4] = c_language_chars[c_language];
+
return result;
}
+/* Prepare to write a PCH file, if one is being written. This is
+ called at the start of compilation.
+
+ Also, print out the executable checksum if -fverbose-asm is in effect. */
+
void
-pch_init ()
+pch_init (void)
{
FILE *f;
-
- if (pch_file)
+ struct c_pch_validity v;
+ void *target_validity;
+ static const char partial_pch[] = "gpcWrite";
+
+#ifdef ASM_COMMENT_START
+ if (flag_verbose_asm)
{
- /* We're precompiling a header file, so when it's actually used,
- it'll be at least one level deep. */
- (*debug_hooks->start_source_file) (lineno, input_filename);
-
- f = fopen (pch_file, "w+b");
- if (f == NULL)
- fatal_io_error ("can't open %s", pch_file);
- pch_outfile = f;
-
- if (fwrite (get_ident(), IDENT_LENGTH, 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);
-
- cpp_save_state (parse_in, f);
+ fprintf (asm_out_file, "%s ", ASM_COMMENT_START);
+ c_common_print_pch_checksum (asm_out_file);
+ fputc ('\n', asm_out_file);
}
+#endif
+
+ if (!pch_file)
+ return;
+
+ f = fopen (pch_file, "w+b");
+ if (f == NULL)
+ fatal_error ("can%'t create precompiled header %s: %m", pch_file);
+ pch_outfile = f;
+
+ gcc_assert (memcmp (executable_checksum, no_checksum, 16) != 0);
+
+ v.debug_info_type = write_symbols;
+ {
+ size_t i;
+ for (i = 0; i < MATCH_SIZE; i++)
+ {
+ v.match[i] = *pch_matching[i].flag_var;
+ gcc_assert (v.match[i] == *pch_matching[i].flag_var);
+ }
+ }
+ v.pch_init = &pch_init;
+ target_validity = targetm.get_pch_validity (&v.target_data_length);
+
+ if (fwrite (partial_pch, IDENT_LENGTH, 1, f) != 1
+ || fwrite (executable_checksum, 16, 1, f) != 1
+ || fwrite (&v, sizeof (v), 1, f) != 1
+ || fwrite (target_validity, v.target_data_length, 1, f) != 1)
+ fatal_error ("can%'t write to %s: %m", 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 ("%qs 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 ()
+c_common_write_pch (void)
{
char *buf;
long asm_file_end;
long written;
struct c_pch_header h;
+ (*debug_hooks->handle_pch) (1);
+
cpp_write_pch_deps (parse_in, pch_outfile);
asm_file_end = ftell (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);
+ fatal_error ("can%'t write %s: %m", pch_file);
+
+ buf = XNEWVEC (char, 16384);
if (fseek (asm_out_file, asm_file_startpos, SEEK_SET) != 0)
- fatal_io_error ("can't seek in %s", asm_file_name);
+ fatal_error ("can%'t seek in %s: %m", asm_file_name);
for (written = asm_file_startpos; written < asm_file_end; )
{
if (size > 16384)
size = 16384;
if (fread (buf, size, 1, asm_out_file) != 1)
- fatal_io_error ("can't read %s", asm_file_name);
+ fatal_error ("can%'t read %s: %m", asm_file_name);
if (fwrite (buf, size, 1, pch_outfile) != 1)
- fatal_io_error ("can't write %s", pch_file);
+ fatal_error ("can%'t write %s: %m", pch_file);
written += size;
}
free (buf);
+ /* asm_out_file can be written afterwards, so fseek to clear
+ _IOREAD flag. */
+ if (fseek (asm_out_file, 0, SEEK_END) != 0)
+ fatal_error ("can%'t seek in %s: %m", asm_file_name);
gt_pch_save (pch_outfile);
cpp_write_pch_state (parse_in, pch_outfile);
+ if (fseek (pch_outfile, 0, SEEK_SET) != 0
+ || fwrite (get_ident (), IDENT_LENGTH, 1, pch_outfile) != 1)
+ fatal_error ("can%'t write %s: %m", pch_file);
+
fclose (pch_outfile);
}
+/* Check the PCH file called NAME, open on FD, to see if it can be
+ used in this compilation. Return 1 if valid, 0 if the file can't
+ be used now but might be if it's seen later in the compilation, and
+ 2 if this file could never be used in the compilation. */
+
int
-c_common_valid_pch (pfile, name, fd)
- cpp_reader *pfile;
- const char *name;
- int fd;
+c_common_valid_pch (cpp_reader *pfile, const char *name, int fd)
{
int sizeread;
int result;
- char ident[IDENT_LENGTH];
+ char ident[IDENT_LENGTH + 16];
const char *pch_ident;
-
- if (! allow_pch)
- return 2;
+ struct c_pch_validity v;
/* Perform a quick test of whether this is a valid
- precompiled header for C. */
+ precompiled header for the current language. */
+
+ gcc_assert (memcmp (executable_checksum, no_checksum, 16) != 0);
- sizeread = read (fd, ident, IDENT_LENGTH);
+ sizeread = read (fd, ident, IDENT_LENGTH + 16);
if (sizeread == -1)
+ fatal_error ("can%'t read %s: %m", name);
+ else if (sizeread != IDENT_LENGTH + 16)
{
- fatal_io_error ("can't read %s", name);
+ if (cpp_get_options (pfile)->warn_invalid_pch)
+ cpp_error (pfile, CPP_DL_WARNING, "%s: too short to be a PCH file",
+ name);
return 2;
}
- else if (sizeread != IDENT_LENGTH)
- return 2;
-
+
pch_ident = get_ident();
if (memcmp (ident, pch_ident, IDENT_LENGTH) != 0)
{
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,
+ cpp_error (pfile, CPP_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,
+ cpp_error (pfile, CPP_DL_WARNING, "%s: not for %s", name,
lang_hooks.name);
- else
+ else
/* Not any kind of PCH. */
- cpp_error (pfile, DL_WARNING, "%s: not a PCH file", name);
+ cpp_error (pfile, CPP_DL_WARNING, "%s: not a PCH file", name);
}
return 2;
}
+ if (memcmp (ident + IDENT_LENGTH, executable_checksum, 16) != 0)
+ {
+ if (cpp_get_options (pfile)->warn_invalid_pch)
+ cpp_error (pfile, CPP_DL_WARNING,
+ "%s: created by a different GCC executable", name);
+ return 2;
+ }
+
+ /* At this point, we know it's a PCH file created by this
+ executable, so it ought to be long enough that we can read a
+ c_pch_validity structure. */
+ if (read (fd, &v, sizeof (v)) != sizeof (v))
+ fatal_error ("can%'t read %s: %m", name);
+
+ /* 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, CPP_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 flags that must match exactly. */
+ {
+ size_t i;
+ for (i = 0; i < MATCH_SIZE; i++)
+ if (*pch_matching[i].flag_var != v.match[i])
+ {
+ if (cpp_get_options (pfile)->warn_invalid_pch)
+ cpp_error (pfile, CPP_DL_WARNING,
+ "%s: settings for %s do not match", name,
+ pch_matching[i].flag_name);
+ return 2;
+ }
+ }
+
+ /* If the text segment was not loaded at the same address as it was
+ when the PCH file was created, function pointers loaded from the
+ PCH will not be valid. We could in theory remap all the function
+ pointers, but no support for that exists at present.
+ Since we have the same executable, it should only be necessary to
+ check one function. */
+ if (v.pch_init != &pch_init)
+ {
+ if (cpp_get_options (pfile)->warn_invalid_pch)
+ cpp_error (pfile, CPP_DL_WARNING,
+ "%s: had text segment at different address", name);
+ return 2;
+ }
+
+ /* Check the target-specific validity data. */
+ {
+ void *this_file_data = xmalloc (v.target_data_length);
+ const char *msg;
+
+ if ((size_t) read (fd, this_file_data, v.target_data_length)
+ != v.target_data_length)
+ fatal_error ("can%'t read %s: %m", name);
+ msg = targetm.pch_valid_p (this_file_data, v.target_data_length);
+ free (this_file_data);
+ if (msg != NULL)
+ {
+ if (cpp_get_options (pfile)->warn_invalid_pch)
+ cpp_error (pfile, CPP_DL_WARNING, "%s: %s", name, msg);
+ 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;
return result == 0;
}
+/* If non-NULL, this function is called after a precompile header file
+ is loaded. */
+void (*lang_post_pch_load) (void);
+
+/* 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;
+c_common_read_pch (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;
-
- /* Before we wrote the file, we started a source file, so we have to start
- one here to match. */
- (*debug_hooks->start_source_file) (lineno, orig_name);
-
+ expanded_location saved_loc;
+ bool saved_trace_includes;
+
f = fdopen (fd, "rb");
if (f == NULL)
{
- cpp_errno (pfile, DL_ERROR, "calling fdopen");
+ cpp_errno (pfile, CPP_DL_ERROR, "calling fdopen");
+ close (fd);
return;
}
- allow_pch = 0;
+ cpp_get_callbacks (parse_in)->valid_pch = NULL;
if (fread (&h, sizeof (h), 1, f) != 1)
{
- cpp_errno (pfile, DL_ERROR, "reading");
+ cpp_errno (pfile, CPP_DL_ERROR, "reading");
+ fclose (f);
return;
}
- buf = xmalloc (16384);
- for (written = 0; written < h.asm_size; )
+ if (!flag_preprocess_only)
{
- long size = h.asm_size - written;
- if (size > 16384)
- size = 16384;
- if (fread (buf, size, 1, f) != 1
- || fwrite (buf, size, 1, asm_out_file) != 1)
- cpp_errno (pfile, DL_ERROR, "reading");
- written += size;
+ unsigned long written;
+ char * buf = XNEWVEC (char, 16384);
+
+ for (written = 0; written < h.asm_size; )
+ {
+ long size = h.asm_size - written;
+ if (size > 16384)
+ size = 16384;
+ if (fread (buf, size, 1, f) != 1
+ || fwrite (buf, size, 1, asm_out_file) != 1)
+ cpp_errno (pfile, CPP_DL_ERROR, "reading");
+ written += size;
+ }
+ free (buf);
+ }
+ else
+ {
+ /* If we're preprocessing, don't write to a NULL
+ asm_out_file. */
+ if (fseek (f, h.asm_size, SEEK_CUR) != 0)
+ cpp_errno (pfile, CPP_DL_ERROR, "seeking");
}
- free (buf);
+
+ /* Save the location and then restore it after reading the PCH. */
+ saved_loc = expand_location (line_table->highest_line);
+ saved_trace_includes = line_table->trace_includes;
cpp_prepare_state (pfile, &smd);
gt_pch_restore (f);
if (cpp_read_state (pfile, name, f, smd) != 0)
- return;
+ {
+ fclose (f);
+ return;
+ }
fclose (f);
- (*debug_hooks->end_source_file) (lineno);
+ line_table->trace_includes = saved_trace_includes;
+ cpp_set_line_map (pfile, line_table);
+ linemap_add (line_table, LC_RENAME, 0, saved_loc.file, saved_loc.line);
+
+ /* Give the front end a chance to take action after a PCH file has
+ been loaded. */
+ if (lang_post_pch_load)
+ (*lang_post_pch_load) ();
+}
+
+/* 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, -1, 0);
+ }
+}
+
+/* Handle #pragma GCC pch_preprocess, to load in the PCH file. */
+
+#ifndef O_BINARY
+# define O_BINARY 0
+#endif
+
+void
+c_common_pch_pragma (cpp_reader *pfile, const char *name)
+{
+ int fd;
+
+ if (!cpp_get_options (pfile)->preprocessed)
+ {
+ error ("pch_preprocess pragma should only be used with -fpreprocessed");
+ inform (input_location, "use #include instead");
+ return;
+ }
+
+ fd = open (name, O_RDONLY | O_BINARY, 0666);
+ if (fd == -1)
+ fatal_error ("%s: couldn%'t open PCH file: %m", name);
+
+ if (c_common_valid_pch (pfile, name, fd) != 1)
+ {
+ if (!cpp_get_options (pfile)->warn_invalid_pch)
+ inform (input_location, "use -Winvalid-pch for more information");
+ fatal_error ("%s: PCH file was invalid", name);
+ }
+
+ c_common_read_pch (pfile, name, fd, name);
+
+ close (fd);
+}
+
+/* Print out executable_checksum[]. */
+
+void
+c_common_print_pch_checksum (FILE *f)
+{
+ int i;
+ fputs ("Compiler executable checksum: ", f);
+ for (i = 0; i < 16; i++)
+ fprintf (f, "%02x", executable_checksum[i]);
+ putc ('\n', f);
}