2004-08-18 David Daney <ddaney@avtrex.com>
[official-gcc.git] / libcpp / pch.c
bloba343cd857f01ddff22ed1512bfe8182a0493a051
1 /* Part of CPP library. (Precompiled header reading/writing.)
2 Copyright (C) 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
4 This program is free software; you can redistribute it and/or modify it
5 under the terms of the GNU General Public License as published by the
6 Free Software Foundation; either version 2, or (at your option) any
7 later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
18 #include "config.h"
19 #include "system.h"
20 #include "cpplib.h"
21 #include "internal.h"
22 #include "hashtab.h"
23 #include "mkdeps.h"
25 static int write_macdef (cpp_reader *, cpp_hashnode *, void *);
26 static int save_idents (cpp_reader *, cpp_hashnode *, void *);
27 static hashval_t hashmem (const void *, size_t);
28 static hashval_t cpp_string_hash (const void *);
29 static int cpp_string_eq (const void *, const void *);
30 static int count_defs (cpp_reader *, cpp_hashnode *, void *);
31 static int comp_hashnodes (const void *, const void *);
32 static int collect_ht_nodes (cpp_reader *, cpp_hashnode *, void *);
33 static int write_defs (cpp_reader *, cpp_hashnode *, void *);
34 static int save_macros (cpp_reader *, cpp_hashnode *, void *);
36 /* This structure represents a macro definition on disk. */
37 struct macrodef_struct
39 unsigned int definition_length;
40 unsigned short name_length;
41 unsigned short flags;
44 /* This is how we write out a macro definition.
45 Suitable for being called by cpp_forall_identifiers. */
47 static int
48 write_macdef (cpp_reader *pfile, cpp_hashnode *hn, void *file_p)
50 FILE *f = (FILE *) file_p;
51 switch (hn->type)
53 case NT_VOID:
54 if (! (hn->flags & NODE_POISONED))
55 return 1;
57 case NT_MACRO:
58 if ((hn->flags & NODE_BUILTIN))
59 return 1;
62 struct macrodef_struct s;
63 const unsigned char *defn;
65 s.name_length = NODE_LEN (hn);
66 s.flags = hn->flags & NODE_POISONED;
68 if (hn->type == NT_MACRO)
70 defn = cpp_macro_definition (pfile, hn);
71 s.definition_length = ustrlen (defn);
73 else
75 defn = NODE_NAME (hn);
76 s.definition_length = s.name_length;
79 if (fwrite (&s, sizeof (s), 1, f) != 1
80 || fwrite (defn, 1, s.definition_length, f) != s.definition_length)
82 cpp_errno (pfile, CPP_DL_ERROR,
83 "while writing precompiled header");
84 return 0;
87 return 1;
89 case NT_ASSERTION:
90 /* Not currently implemented. */
91 return 1;
93 default:
94 abort ();
98 /* This structure records the names of the defined macros.
99 It's also used as a callback structure for size_initial_idents
100 and save_idents. */
102 struct cpp_savedstate
104 /* A hash table of the defined identifiers. */
105 htab_t definedhash;
106 /* The size of the definitions of those identifiers (the size of
107 'definedstrs'). */
108 size_t hashsize;
109 /* Number of definitions */
110 size_t n_defs;
111 /* Array of definitions. In cpp_write_pch_deps it is used for sorting. */
112 cpp_hashnode **defs;
113 /* Space for the next definition. Definitions are null-terminated
114 strings. */
115 unsigned char *definedstrs;
118 /* Save this identifier into the state: put it in the hash table,
119 put the definition in 'definedstrs'. */
121 static int
122 save_idents (cpp_reader *pfile ATTRIBUTE_UNUSED, cpp_hashnode *hn, void *ss_p)
124 struct cpp_savedstate *const ss = (struct cpp_savedstate *)ss_p;
126 if (hn->type != NT_VOID)
128 struct cpp_string news;
129 void **slot;
131 news.len = NODE_LEN (hn);
132 news.text= NODE_NAME (hn);
133 slot = htab_find_slot (ss->definedhash, &news, INSERT);
134 if (*slot == NULL)
136 struct cpp_string *sp;
137 unsigned char *text;
139 sp = xmalloc (sizeof (struct cpp_string));
140 *slot = sp;
142 sp->len = NODE_LEN (hn);
143 sp->text = text = xmalloc (NODE_LEN (hn));
144 memcpy (text, NODE_NAME (hn), NODE_LEN (hn));
148 return 1;
151 /* Hash some memory in a generic way. */
153 static hashval_t
154 hashmem (const void *p_p, size_t sz)
156 const unsigned char *p = (const unsigned char *)p_p;
157 size_t i;
158 hashval_t h;
160 h = 0;
161 for (i = 0; i < sz; i++)
162 h = h * 67 - (*p++ - 113);
163 return h;
166 /* Hash a cpp string for the hashtable machinery. */
168 static hashval_t
169 cpp_string_hash (const void *a_p)
171 const struct cpp_string *a = (const struct cpp_string *) a_p;
172 return hashmem (a->text, a->len);
175 /* Compare two cpp strings for the hashtable machinery. */
177 static int
178 cpp_string_eq (const void *a_p, const void *b_p)
180 const struct cpp_string *a = (const struct cpp_string *) a_p;
181 const struct cpp_string *b = (const struct cpp_string *) b_p;
182 return (a->len == b->len
183 && memcmp (a->text, b->text, a->len) == 0);
186 /* Save the current definitions of the cpp_reader for dependency
187 checking purposes. When writing a precompiled header, this should
188 be called at the same point in the compilation as cpp_valid_state
189 would be called when reading the precompiled header back in. */
192 cpp_save_state (cpp_reader *r, FILE *f)
194 /* Save the list of non-void identifiers for the dependency checking. */
195 r->savedstate = xmalloc (sizeof (struct cpp_savedstate));
196 r->savedstate->definedhash = htab_create (100, cpp_string_hash,
197 cpp_string_eq, NULL);
198 cpp_forall_identifiers (r, save_idents, r->savedstate);
200 /* Write out the list of defined identifiers. */
201 cpp_forall_identifiers (r, write_macdef, f);
203 return 0;
206 /* Calculate the 'hashsize' field of the saved state. */
208 static int
209 count_defs (cpp_reader *pfile ATTRIBUTE_UNUSED, cpp_hashnode *hn, void *ss_p)
211 struct cpp_savedstate *const ss = (struct cpp_savedstate *)ss_p;
213 switch (hn->type)
215 case NT_MACRO:
216 if (hn->flags & NODE_BUILTIN)
217 return 1;
219 /* else fall through. */
221 case NT_VOID:
223 struct cpp_string news;
224 void **slot;
226 news.len = NODE_LEN (hn);
227 news.text = NODE_NAME (hn);
228 slot = htab_find (ss->definedhash, &news);
229 if (slot == NULL)
231 ss->hashsize += NODE_LEN (hn) + 1;
232 ss->n_defs += 1;
235 return 1;
237 case NT_ASSERTION:
238 /* Not currently implemented. */
239 return 1;
241 default:
242 abort ();
246 /* Collect the identifiers into the state's string table. */
247 static int
248 write_defs (cpp_reader *pfile ATTRIBUTE_UNUSED, cpp_hashnode *hn, void *ss_p)
250 struct cpp_savedstate *const ss = (struct cpp_savedstate *)ss_p;
252 switch (hn->type)
254 case NT_MACRO:
255 if (hn->flags & NODE_BUILTIN)
256 return 1;
258 /* else fall through. */
260 case NT_VOID:
262 struct cpp_string news;
263 void **slot;
265 news.len = NODE_LEN (hn);
266 news.text = NODE_NAME (hn);
267 slot = htab_find (ss->definedhash, &news);
268 if (slot == NULL)
270 ss->defs[ss->n_defs] = hn;
271 ss->n_defs += 1;
274 return 1;
276 case NT_ASSERTION:
277 /* Not currently implemented. */
278 return 1;
280 default:
281 abort ();
285 /* Comparison function for qsort. The arguments point to pointers of
286 type ht_hashnode *. */
287 static int
288 comp_hashnodes (const void *px, const void *py)
290 cpp_hashnode *x = *(cpp_hashnode **) px;
291 cpp_hashnode *y = *(cpp_hashnode **) py;
292 return ustrcmp (NODE_NAME (x), NODE_NAME (y));
295 /* Write out the remainder of the dependency information. This should be
296 called after the PCH is ready to be saved. */
299 cpp_write_pch_deps (cpp_reader *r, FILE *f)
301 struct macrodef_struct z;
302 struct cpp_savedstate *const ss = r->savedstate;
303 unsigned char *definedstrs;
304 size_t i;
306 /* Collect the list of identifiers which have been seen and
307 weren't defined to anything previously. */
308 ss->hashsize = 0;
309 ss->n_defs = 0;
310 cpp_forall_identifiers (r, count_defs, ss);
312 ss->defs = xmalloc (ss->n_defs * sizeof (cpp_hashnode *));
313 ss->n_defs = 0;
314 cpp_forall_identifiers (r, write_defs, ss);
316 /* Sort the list, copy it into a buffer, and write it out. */
317 qsort (ss->defs, ss->n_defs, sizeof (cpp_hashnode *), &comp_hashnodes);
318 definedstrs = ss->definedstrs = xmalloc (ss->hashsize);
319 for (i = 0; i < ss->n_defs; ++i)
321 size_t len = NODE_LEN (ss->defs[i]);
322 memcpy (definedstrs, NODE_NAME (ss->defs[i]), len + 1);
323 definedstrs += len + 1;
326 memset (&z, 0, sizeof (z));
327 z.definition_length = ss->hashsize;
328 if (fwrite (&z, sizeof (z), 1, f) != 1
329 || fwrite (ss->definedstrs, ss->hashsize, 1, f) != 1)
331 cpp_errno (r, CPP_DL_ERROR, "while writing precompiled header");
332 return -1;
334 free (ss->definedstrs);
336 /* Free the saved state. */
337 free (ss);
338 r->savedstate = NULL;
339 return 0;
342 /* Write out the definitions of the preprocessor, in a form suitable for
343 cpp_read_state. */
346 cpp_write_pch_state (cpp_reader *r, FILE *f)
348 struct macrodef_struct z;
350 if (!r->deps)
351 r->deps = deps_init ();
353 if (deps_save (r->deps, f) != 0)
355 cpp_errno (r, CPP_DL_ERROR, "while writing precompiled header");
356 return -1;
359 if (! _cpp_save_file_entries (r, f))
361 cpp_errno (r, CPP_DL_ERROR, "while writing precompiled header");
362 return -1;
365 return 0;
369 /* Data structure to transform hash table nodes into a sorted list */
371 struct ht_node_list
373 /* Array of nodes */
374 cpp_hashnode **defs;
375 /* Number of nodes in the array */
376 size_t n_defs;
377 /* Size of the allocated array */
378 size_t asize;
381 /* Callback for collecting identifiers from hash table */
383 static int
384 collect_ht_nodes (cpp_reader *pfile ATTRIBUTE_UNUSED, cpp_hashnode *hn,
385 void *nl_p)
387 struct ht_node_list *const nl = (struct ht_node_list *)nl_p;
389 if (hn->type != NT_VOID || hn->flags & NODE_POISONED)
391 if (nl->n_defs == nl->asize)
393 nl->asize *= 2;
394 nl->defs = xrealloc (nl->defs, nl->asize * sizeof (cpp_hashnode *));
397 nl->defs[nl->n_defs] = hn;
398 ++nl->n_defs;
400 return 1;
404 /* Return nonzero if FD is a precompiled header which is consistent
405 with the preprocessor's current definitions. It will be consistent
406 when:
408 - anything that was defined just before the PCH was generated
409 is defined the same way now; and
410 - anything that was not defined then, but is defined now, was not
411 used by the PCH.
413 NAME is used to print warnings if `warn_invalid_pch' is set in the
414 reader's flags.
418 cpp_valid_state (cpp_reader *r, const char *name, int fd)
420 struct macrodef_struct m;
421 size_t namebufsz = 256;
422 unsigned char *namebuf = xmalloc (namebufsz);
423 unsigned char *undeftab = NULL;
424 struct ht_node_list nl = { 0, 0, 0 };
425 unsigned char *first, *last;
426 unsigned int i;
428 /* Read in the list of identifiers that must be defined
429 Check that they are defined in the same way. */
430 for (;;)
432 cpp_hashnode *h;
433 const unsigned char *newdefn;
435 if (read (fd, &m, sizeof (m)) != sizeof (m))
436 goto error;
438 if (m.name_length == 0)
439 break;
441 /* If this file is already preprocessed, there won't be any
442 macros defined, and that's OK. */
443 if (CPP_OPTION (r, preprocessed))
445 if (lseek (fd, m.definition_length, SEEK_CUR) == -1)
446 goto error;
447 continue;
450 if (m.definition_length > namebufsz)
452 free (namebuf);
453 namebufsz = m.definition_length + 256;
454 namebuf = xmalloc (namebufsz);
457 if ((size_t)read (fd, namebuf, m.definition_length)
458 != m.definition_length)
459 goto error;
461 h = cpp_lookup (r, namebuf, m.name_length);
462 if (m.flags & NODE_POISONED
463 || h->type != NT_MACRO
464 || h->flags & NODE_POISONED)
466 if (CPP_OPTION (r, warn_invalid_pch))
467 cpp_error (r, CPP_DL_WARNING_SYSHDR,
468 "%s: not used because `%.*s' not defined",
469 name, m.name_length, namebuf);
470 goto fail;
473 newdefn = cpp_macro_definition (r, h);
475 if (m.definition_length != ustrlen (newdefn)
476 || memcmp (namebuf, newdefn, m.definition_length) != 0)
478 if (CPP_OPTION (r, warn_invalid_pch))
479 cpp_error (r, CPP_DL_WARNING_SYSHDR,
480 "%s: not used because `%.*s' defined as `%s' not `%.*s'",
481 name, m.name_length, namebuf, newdefn + m.name_length,
482 m.definition_length - m.name_length,
483 namebuf + m.name_length);
484 goto fail;
487 free (namebuf);
488 namebuf = NULL;
490 /* Read in the list of identifiers that must not be defined.
491 Check that they really aren't. */
492 undeftab = xmalloc (m.definition_length);
493 if ((size_t) read (fd, undeftab, m.definition_length) != m.definition_length)
494 goto error;
496 /* Collect identifiers from the current hash table. */
497 nl.n_defs = 0;
498 nl.asize = 10;
499 nl.defs = xmalloc (nl.asize * sizeof (cpp_hashnode *));
500 cpp_forall_identifiers (r, &collect_ht_nodes, &nl);
501 qsort (nl.defs, nl.n_defs, sizeof (cpp_hashnode *), &comp_hashnodes);
503 /* Loop through nl.defs and undeftab, both of which are sorted lists.
504 There should be no matches. */
505 first = undeftab;
506 last = undeftab + m.definition_length;
507 i = 0;
509 while (first < last && i < nl.n_defs)
511 int cmp = ustrcmp (first, NODE_NAME (nl.defs[i]));
513 if (cmp < 0)
514 first += ustrlen (first) + 1;
515 else if (cmp > 0)
516 ++i;
517 else
519 if (CPP_OPTION (r, warn_invalid_pch))
520 cpp_error (r, CPP_DL_WARNING_SYSHDR,
521 "%s: not used because `%s' is defined",
522 name, first);
523 goto fail;
527 free(nl.defs);
528 free (undeftab);
530 /* We win! */
531 return 0;
533 error:
534 cpp_errno (r, CPP_DL_ERROR, "while reading precompiled header");
535 return -1;
537 fail:
538 if (namebuf != NULL)
539 free (namebuf);
540 if (undeftab != NULL)
541 free (undeftab);
542 if (nl.defs != NULL)
543 free (nl.defs);
544 return 1;
547 /* Save all the existing macros. */
549 struct save_macro_data
551 uchar **defns;
552 size_t count;
553 size_t array_size;
554 char **saved_pragmas;
557 /* Save the definition of a single macro, so that it will persist
558 across a PCH restore. Because macro data is in GCed memory, which
559 will be blown away by PCH, it must be temporarily copied to
560 malloced memory. (The macros will refer to identifier nodes which
561 are also GCed and so on, so the copying is done by turning them
562 into self-contained strings.) The assumption is that most macro
563 definitions will come from the PCH file, not from the compilation
564 before the PCH file is loaded, so it doesn't matter that this is
565 a little expensive.
567 It would reduce the cost even further if macros defined in the PCH
568 file were not saved in this way, but this is not done (yet), except
569 for builtins, and for #assert by default. */
571 static int
572 save_macros (cpp_reader *r, cpp_hashnode *h, void *data_p)
574 struct save_macro_data *data = (struct save_macro_data *)data_p;
575 if (h->type != NT_VOID
576 && (h->flags & NODE_BUILTIN) == 0)
578 if (data->count == data->array_size)
580 data->array_size *= 2;
581 data->defns = xrealloc (data->defns, (data->array_size
582 * sizeof (uchar *)));
585 switch (h->type)
587 case NT_ASSERTION:
588 /* Not currently implemented. */
589 return 1;
591 case NT_MACRO:
593 const uchar * defn = cpp_macro_definition (r, h);
594 size_t defnlen = ustrlen (defn);
596 data->defns[data->count] = xmemdup (defn, defnlen, defnlen + 2);
597 data->defns[data->count][defnlen] = '\n';
599 break;
601 default:
602 abort ();
604 data->count++;
606 return 1;
609 /* Prepare to restore the state, by saving the currently-defined
610 macros in 'data'. */
612 void
613 cpp_prepare_state (cpp_reader *r, struct save_macro_data **data)
615 struct save_macro_data *d = xmalloc (sizeof (struct save_macro_data));
617 d->array_size = 512;
618 d->defns = xmalloc (d->array_size * sizeof (d->defns[0]));
619 d->count = 0;
620 cpp_forall_identifiers (r, save_macros, d);
621 d->saved_pragmas = _cpp_save_pragma_names (r);
622 *data = d;
625 /* Given a precompiled header that was previously determined to be valid,
626 apply all its definitions (and undefinitions) to the current state.
627 DEPNAME is passed to deps_restore. */
630 cpp_read_state (cpp_reader *r, const char *name, FILE *f,
631 struct save_macro_data *data)
633 struct macrodef_struct m;
634 struct save_macro_item *d;
635 size_t i, mac_count;
636 struct lexer_state old_state;
638 /* Restore spec_nodes, which will be full of references to the old
639 hashtable entries and so will now be invalid. */
641 struct spec_nodes *s = &r->spec_nodes;
642 s->n_defined = cpp_lookup (r, DSC("defined"));
643 s->n_true = cpp_lookup (r, DSC("true"));
644 s->n_false = cpp_lookup (r, DSC("false"));
645 s->n__VA_ARGS__ = cpp_lookup (r, DSC("__VA_ARGS__"));
648 old_state = r->state;
649 r->state.in_directive = 1;
650 r->state.prevent_expansion = 1;
651 r->state.angled_headers = 0;
653 /* Run through the carefully-saved macros, insert them. */
654 for (i = 0; i < data->count; i++)
656 cpp_hashnode *h;
657 size_t namelen;
658 uchar *defn;
660 namelen = strcspn (data->defns[i], "( \n");
661 h = cpp_lookup (r, data->defns[i], namelen);
662 defn = data->defns[i] + namelen;
664 /* The PCH file is valid, so we know that if there is a definition
665 from the PCH file it must be the same as the one we had
666 originally, and so do not need to restore it. */
667 if (h->type == NT_VOID)
669 if (cpp_push_buffer (r, defn, ustrchr (defn, '\n') - defn, true)
670 != NULL)
672 _cpp_clean_line (r);
673 if (!_cpp_create_definition (r, h))
674 abort ();
675 _cpp_pop_buffer (r);
677 else
678 abort ();
681 free (data->defns[i]);
683 r->state = old_state;
685 _cpp_restore_pragma_names (r, data->saved_pragmas);
687 free (data);
689 if (deps_restore (r->deps, f, CPP_OPTION (r, restore_pch_deps) ? name : NULL)
690 != 0)
691 goto error;
693 if (! _cpp_read_file_entries (r, f))
694 goto error;
696 return 0;
698 error:
699 cpp_errno (r, CPP_DL_ERROR, "while reading precompiled header");
700 return -1;