1 /* Precompiled header implementation for the C languages.
2 Copyright (C) 2000, 2002, 2003 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GCC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING. If not, write to
18 the Free Software Foundation, 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
23 #include "coretypes.h"
33 #include "langhooks.h"
37 unsigned char debug_info_type;
42 unsigned long asm_size;
45 #define IDENT_LENGTH 8
47 static FILE *pch_outfile;
49 static long asm_file_startpos;
51 static const char *get_ident (void);
53 /* Compute an appropriate 8-byte magic number for the PCH file, so that
54 utilities like file(1) can identify it, and so that GCC can quickly
55 ignore non-PCH files and PCH files that are of a completely different
61 static char result[IDENT_LENGTH];
62 static const char template[IDENT_LENGTH] = "gpch.011";
64 memcpy (result, template, IDENT_LENGTH);
65 if (c_language == clk_c)
66 result[4] = flag_objc ? 'o' : 'C';
67 else if (c_language == clk_cplusplus)
68 result[4] = flag_objc ? 'O' : '+';
74 /* Prepare to write a PCH file. This is called at the start of
81 struct c_pch_validity v;
86 f = fopen (pch_file, "w+b");
88 fatal_error ("can't open %s: %m", pch_file);
91 v.debug_info_type = write_symbols;
92 if (fwrite (get_ident(), IDENT_LENGTH, 1, f) != 1
93 || fwrite (&v, sizeof (v), 1, f) != 1)
94 fatal_error ("can't write to %s: %m", pch_file);
96 /* We need to be able to re-read the output. */
97 /* The driver always provides a valid -o option. */
98 if (asm_file_name == NULL
99 || strcmp (asm_file_name, "-") == 0)
100 fatal_error ("`%s' is not a valid output file", asm_file_name);
102 asm_file_startpos = ftell (asm_out_file);
104 /* Let the debugging format deal with the PCHness. */
105 (*debug_hooks->handle_pch) (0);
107 cpp_save_state (parse_in, f);
110 /* Write the PCH file. This is called at the end of a compilation which
111 will produce a PCH file. */
114 c_common_write_pch (void)
119 struct c_pch_header h;
121 (*debug_hooks->handle_pch) (1);
123 cpp_write_pch_deps (parse_in, pch_outfile);
125 asm_file_end = ftell (asm_out_file);
126 h.asm_size = asm_file_end - asm_file_startpos;
128 if (fwrite (&h, sizeof (h), 1, pch_outfile) != 1)
129 fatal_error ("can't write %s: %m", pch_file);
131 buf = xmalloc (16384);
132 fflush (asm_out_file);
134 if (fseek (asm_out_file, asm_file_startpos, SEEK_SET) != 0)
135 fatal_error ("can't seek in %s: %m", asm_file_name);
137 for (written = asm_file_startpos; written < asm_file_end; )
139 long size = asm_file_end - written;
142 if (fread (buf, size, 1, asm_out_file) != 1)
143 fatal_error ("can't read %s: %m", asm_file_name);
144 if (fwrite (buf, size, 1, pch_outfile) != 1)
145 fatal_error ("can't write %s: %m", pch_file);
149 /* asm_out_file can be written afterwards, so must be flushed first. */
150 fflush (asm_out_file);
152 gt_pch_save (pch_outfile);
153 cpp_write_pch_state (parse_in, pch_outfile);
155 fclose (pch_outfile);
158 /* Check the PCH file called NAME, open on FD, to see if it can be used
159 in this compilation. */
162 c_common_valid_pch (cpp_reader *pfile, const char *name, int fd)
166 char ident[IDENT_LENGTH];
167 const char *pch_ident;
168 struct c_pch_validity v;
173 /* Perform a quick test of whether this is a valid
174 precompiled header for the current language. */
176 sizeread = read (fd, ident, IDENT_LENGTH);
178 fatal_error ("can't read %s: %m", name);
179 else if (sizeread != IDENT_LENGTH)
182 pch_ident = get_ident();
183 if (memcmp (ident, pch_ident, IDENT_LENGTH) != 0)
185 if (cpp_get_options (pfile)->warn_invalid_pch)
187 if (memcmp (ident, pch_ident, 5) == 0)
188 /* It's a PCH, for the right language, but has the wrong version.
190 cpp_error (pfile, DL_WARNING,
191 "%s: not compatible with this GCC version", name);
192 else if (memcmp (ident, pch_ident, 4) == 0)
193 /* It's a PCH for the wrong language. */
194 cpp_error (pfile, DL_WARNING, "%s: not for %s", name,
197 /* Not any kind of PCH. */
198 cpp_error (pfile, DL_WARNING, "%s: not a PCH file", name);
203 if (read (fd, &v, sizeof (v)) != sizeof (v))
204 fatal_error ("can't read %s: %m", name);
206 /* The allowable debug info combinations are that either the PCH file
207 was built with the same as is being used now, or the PCH file was
208 built for some kind of debug info but now none is in use. */
209 if (v.debug_info_type != write_symbols
210 && write_symbols != NO_DEBUG)
212 if (cpp_get_options (pfile)->warn_invalid_pch)
213 cpp_error (pfile, DL_WARNING,
214 "%s: created with -g%s, but used with -g%s", name,
215 debug_type_names[v.debug_info_type],
216 debug_type_names[write_symbols]);
220 /* Check the preprocessor macros are the same as when the PCH was
223 result = cpp_valid_state (pfile, name, fd);
230 /* Load in the PCH file NAME, open on FD. It was originally searched for
234 c_common_read_pch (cpp_reader *pfile, const char *name,
235 int fd, const char *orig_name ATTRIBUTE_UNUSED)
238 struct c_pch_header h;
240 unsigned long written;
241 struct save_macro_data *smd;
243 f = fdopen (fd, "rb");
246 cpp_errno (pfile, DL_ERROR, "calling fdopen");
252 if (fread (&h, sizeof (h), 1, f) != 1)
254 cpp_errno (pfile, DL_ERROR, "reading");
258 buf = xmalloc (16384);
259 for (written = 0; written < h.asm_size; )
261 long size = h.asm_size - written;
264 if (fread (buf, size, 1, f) != 1
265 || fwrite (buf, size, 1, asm_out_file) != 1)
266 cpp_errno (pfile, DL_ERROR, "reading");
271 cpp_prepare_state (pfile, &smd);
275 if (cpp_read_state (pfile, name, f, smd) != 0)