1 /* Part of CPP library. (include file handling)
2 Copyright (C) 1986, 1987, 1989, 1992, 1993, 1994, 1995, 1998,
3 1999, 2000, 2001 Free Software Foundation, Inc.
4 Written by Per Bothner, 1994.
5 Based on CCCP program by Paul Rubin, June 1986
6 Adapted to ANSI C, Richard Stallman, Jan 1987
7 Split out of cpplib.c, Zack Weinberg, Oct 1998
9 This program is free software; you can redistribute it and/or modify it
10 under the terms of the GNU General Public License as published by the
11 Free Software Foundation; either version 2, or (at your option) any
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program; if not, write to the Free Software
21 Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
29 #include "splay-tree.h"
32 # include <sys/mman.h>
33 # ifndef MMAP_THRESHOLD
34 # define MMAP_THRESHOLD 3 /* Minimum page count to mmap the file. */
37 #else /* No MMAP_FILE */
38 # undef MMAP_THRESHOLD
39 # define MMAP_THRESHOLD 0
46 /* If errno is inspected immediately after a system call fails, it will be
47 nonzero, and no error number will ever be zero. */
55 /* Suppress warning about function macros used w/o arguments in traditional
56 C. It is unlikely that glibc's strcmp macro helps this file at all. */
59 /* This structure is used for the table of all includes. */
62 const char *name; /* actual path name of file */
63 const cpp_hashnode *cmacro; /* macro, if any, preventing reinclusion. */
64 const struct search_path *foundhere;
65 /* location in search path where file was
66 found, for #include_next and sysp. */
67 const unsigned char *buffer; /* pointer to cached file contents */
68 struct stat st; /* copy of stat(2) data for file */
69 int fd; /* fd open on file (short term storage only) */
70 int err_no; /* errno obtained if opening a file failed */
71 unsigned short include_count; /* number of times file has been read */
72 unsigned short refcnt; /* number of stacked buffers using this file */
73 unsigned char mapped; /* file buffer is mmapped */
76 /* The cmacro works like this: If it's NULL, the file is to be
77 included again. If it's NEVER_REREAD, the file is never to be
78 included again. Otherwise it is a macro hashnode, and the file is
79 to be included again if the macro is defined. */
80 #define NEVER_REREAD ((const cpp_hashnode *)-1)
81 #define DO_NOT_REREAD(inc) \
82 ((inc)->cmacro && ((inc)->cmacro == NEVER_REREAD \
83 || (inc)->cmacro->type == NT_MACRO))
84 #define NO_INCLUDE_PATH ((struct include_file *) -1)
86 static struct file_name_map *read_name_map
87 PARAMS ((cpp_reader *, const char *));
88 static char *read_filename_string PARAMS ((int, FILE *));
89 static char *remap_filename PARAMS ((cpp_reader *, char *,
90 struct search_path *));
91 static struct search_path *search_from PARAMS ((cpp_reader *,
93 static struct include_file *
94 find_include_file PARAMS ((cpp_reader *, const cpp_token *,
96 static struct include_file *open_file PARAMS ((cpp_reader *, const char *));
97 static int read_include_file PARAMS ((cpp_reader *, struct include_file *));
98 static void stack_include_file PARAMS ((cpp_reader *, struct include_file *));
99 static void purge_cache PARAMS ((struct include_file *));
100 static void destroy_node PARAMS ((splay_tree_value));
101 static int report_missing_guard PARAMS ((splay_tree_node, void *));
102 static splay_tree_node find_or_create_entry PARAMS ((cpp_reader *,
104 static void handle_missing_header PARAMS ((cpp_reader *, const char *, int));
105 static int remove_component_p PARAMS ((const char *));
107 /* Set up the splay tree we use to store information about all the
108 file names seen in this compilation. We also have entries for each
109 file we tried to open but failed; this saves system calls since we
110 don't try to open it again in future.
112 The key of each node is the file name, after processing by
113 _cpp_simplify_pathname. The path name may or may not be absolute.
114 The path string has been malloced, as is automatically freed by
115 registering free () as the splay tree key deletion function.
117 A node's value is a pointer to a struct include_file, and is never
120 _cpp_init_includes (pfile)
123 pfile->all_include_files
124 = splay_tree_new ((splay_tree_compare_fn) strcmp,
125 (splay_tree_delete_key_fn) free,
129 /* Tear down the splay tree. */
131 _cpp_cleanup_includes (pfile)
134 splay_tree_delete (pfile->all_include_files);
137 /* Free a node. The path string is automatically freed. */
142 struct include_file *f = (struct include_file *)v;
151 /* Mark a file to not be reread (e.g. #import, read failure). */
153 _cpp_never_reread (file)
154 struct include_file *file;
156 file->cmacro = NEVER_REREAD;
159 /* Lookup a filename, which is simplified after making a copy, and
160 create an entry if none exists. errno is nonzero iff a (reported)
161 stat() error occurred during simplification. */
162 static splay_tree_node
163 find_or_create_entry (pfile, fname)
167 splay_tree_node node;
168 struct include_file *file;
169 char *name = xstrdup (fname);
171 _cpp_simplify_pathname (name);
172 node = splay_tree_lookup (pfile->all_include_files, (splay_tree_key) name);
177 file = xcnew (struct include_file);
179 file->err_no = errno;
180 node = splay_tree_insert (pfile->all_include_files,
181 (splay_tree_key) file->name,
182 (splay_tree_value) file);
188 /* Enter a file name in the splay tree, for the sake of cpp_included. */
190 _cpp_fake_include (pfile, fname)
194 find_or_create_entry (pfile, fname);
197 /* Given a file name, look it up in the cache; if there is no entry,
198 create one with a non-NULL value (regardless of success in opening
199 the file). If the file doesn't exist or is inaccessible, this
200 entry is flagged so we don't attempt to open it again in the
201 future. If the file isn't open, open it. The empty string is
202 interpreted as stdin.
204 Returns an include_file structure with an open file descriptor on
205 success, or NULL on failure. */
207 static struct include_file *
208 open_file (pfile, filename)
210 const char *filename;
212 splay_tree_node nd = find_or_create_entry (pfile, filename);
213 struct include_file *file = (struct include_file *) nd->value;
217 /* Ugh. handle_missing_header () needs errno to be set. */
218 errno = file->err_no;
222 /* Don't reopen an idempotent file. */
223 if (DO_NOT_REREAD (file))
226 /* Don't reopen one which is already loaded. */
227 if (file->buffer != NULL)
230 /* We used to open files in nonblocking mode, but that caused more
231 problems than it solved. Do take care not to acquire a
232 controlling terminal by mistake (this can't happen on sane
233 systems, but paranoia is a virtue).
235 Use the three-argument form of open even though we aren't
236 specifying O_CREAT, to defend against broken system headers.
238 O_BINARY tells some runtime libraries (notably DJGPP) not to do
239 newline translation; we can handle DOS line breaks just fine
242 Special case: the empty string is translated to stdin. */
244 if (filename[0] == '\0')
247 file->fd = open (file->name, O_RDONLY | O_NOCTTY | O_BINARY, 0666);
249 if (file->fd != -1 && fstat (file->fd, &file->st) == 0)
251 /* If it's a directory, we return null and continue the search
252 as the file we're looking for may appear elsewhere in the
254 if (S_ISDIR (file->st.st_mode))
258 /* Mark a regular, zero-length file never-reread now. */
259 if (S_ISREG (file->st.st_mode) && file->st.st_size == 0)
261 _cpp_never_reread (file);
270 /* Don't issue an error message if the file doesn't exist. */
271 file->err_no = errno;
272 if (errno != ENOENT && errno != ENOTDIR)
273 cpp_error_from_errno (pfile, file->name);
278 /* Place the file referenced by INC into a new buffer on PFILE's
279 stack. If there are errors, or the file should not be re-included,
280 a null (zero-length) buffer is pushed. */
283 stack_include_file (pfile, inc)
285 struct include_file *inc;
291 /* We'll try removing deps_sysp after the release of 3.0. */
292 deps_sysp = pfile->system_include_depth != 0;
293 sysp = MAX ((pfile->buffer ? pfile->buffer->sysp : 0),
294 (inc->foundhere ? inc->foundhere->sysp : 0));
296 /* For -M, add the file to the dependencies on its first inclusion. */
297 if (CPP_OPTION (pfile, print_deps) > deps_sysp && !inc->include_count)
298 deps_add_dep (pfile->deps, inc->name);
301 if (! DO_NOT_REREAD (inc) && ! inc->buffer)
303 /* If an error occurs, do not try to read this file again. */
304 if (read_include_file (pfile, inc))
305 _cpp_never_reread (inc);
310 if (! DO_NOT_REREAD (inc))
312 len = inc->st.st_size;
315 /* We don't want MI guard advice for the main file. */
316 inc->include_count++;
318 /* Handle -H option. */
319 if (CPP_OPTION (pfile, print_include_names))
321 for (fp = pfile->buffer; fp; fp = fp->prev)
323 fprintf (stderr, " %s\n", inc->name);
329 fp = cpp_push_buffer (pfile, inc->buffer, len, BUF_FILE, inc->name);
334 /* Initialise controlling macro state. */
335 pfile->mi_state = MI_OUTSIDE;
336 pfile->mi_cmacro = 0;
337 pfile->include_depth++;
339 /* Generate the call back. */
341 _cpp_do_file_change (pfile, FC_ENTER, 0, 0);
345 /* Read the file referenced by INC into the file cache.
347 If fd points to a plain file, we might be able to mmap it; we can
348 definitely allocate the buffer all at once. If fd is a pipe or
349 terminal, we can't do either. If fd is something weird, like a
350 block device, we don't want to read it at all.
352 Unfortunately, different systems use different st.st_mode values
353 for pipes: some have S_ISFIFO, some S_ISSOCK, some are buggy and
354 zero the entire struct stat except a couple fields. Hence we don't
355 even try to figure out what something is, except for plain files
358 FIXME: Flush file cache and try again if we run out of memory. */
361 read_include_file (pfile, inc)
363 struct include_file *inc;
365 ssize_t size, offset, count;
368 static int pagesize = -1;
371 if (S_ISREG (inc->st.st_mode))
373 /* off_t might have a wider range than ssize_t - in other words,
374 the max size of a file might be bigger than the address
375 space. We can't handle a file that large. (Anyone with
376 a single source file bigger than 2GB needs to rethink
377 their coding style.) Some systems (e.g. AIX 4.1) define
378 SSIZE_MAX to be much smaller than the actual range of the
379 type. Use INTTYPE_MAXIMUM unconditionally to ensure this
382 if (inc->st.st_size > INTTYPE_MAXIMUM (ssize_t))
384 cpp_error (pfile, "%s is too large (%lu > %lu)", inc->name,
385 (unsigned long)inc->st.st_size,
386 INTTYPE_MAXIMUM(ssize_t));
390 size = inc->st.st_size;
395 pagesize = getpagesize ();
397 if (size / pagesize >= MMAP_THRESHOLD)
399 buf = (U_CHAR *) mmap (0, size, PROT_READ, MAP_PRIVATE, inc->fd, 0);
400 if (buf == (U_CHAR *)-1)
407 buf = (U_CHAR *) xmalloc (size);
409 while (offset < size)
411 count = read (inc->fd, buf + offset, size - offset);
417 /* For some reason, even though we opened with O_BINARY,
418 * Borland C++ seems to insist on doing CR/LF -> LF
419 * translations for us, which results in the file appearing
420 * shorter than stat told us it should be.
422 * This sucks, but don't bother throwing a warning.
424 cpp_warning (pfile, "%s is shorter than expected (expected %u, got %u)",
425 inc->name, inc->st.st_size, offset);
427 inc->st.st_size = offset;
434 else if (S_ISBLK (inc->st.st_mode))
436 cpp_error (pfile, "%s is a block device", inc->name);
441 /* 8 kilobytes is a sensible starting size. It ought to be
442 bigger than the kernel pipe buffer, and it's definitely
443 bigger than the majority of C source files. */
446 buf = (U_CHAR *) xmalloc (size);
448 while ((count = read (inc->fd, buf + offset, size - offset)) > 0)
452 buf = xrealloc (buf, (size *= 2));
458 buf = xrealloc (buf, offset);
459 inc->st.st_size = offset;
466 cpp_error_from_errno (pfile, inc->name);
473 struct include_file *inc;
479 munmap ((PTR) inc->buffer, inc->st.st_size);
482 free ((PTR) inc->buffer);
487 /* Return 1 if the file named by FNAME has been included before in
488 any context, 0 otherwise. */
490 cpp_included (pfile, fname)
494 struct search_path *path;
498 if (IS_ABSOLUTE_PATHNAME (fname))
500 /* Just look it up. */
501 nd = splay_tree_lookup (pfile->all_include_files, (splay_tree_key) fname);
502 return (nd && nd->value);
505 /* Search directory path for the file. */
506 name = (char *) alloca (strlen (fname) + pfile->max_include_len + 2);
507 for (path = CPP_OPTION (pfile, quote_include); path; path = path->next)
509 memcpy (name, path->name, path->len);
510 name[path->len] = '/';
511 strcpy (&name[path->len + 1], fname);
512 if (CPP_OPTION (pfile, remap))
513 n = remap_filename (pfile, name, path);
517 nd = splay_tree_lookup (pfile->all_include_files, (splay_tree_key) n);
524 /* Search for HEADER. Return 0 if there is no such file (or it's
525 un-openable), in which case an error code will be in errno. If
526 there is no include path to use it returns NO_INCLUDE_PATH,
527 otherwise an include_file structure. If this request originates
528 from a #include_next directive, set INCLUDE_NEXT to true. */
530 static struct include_file *
531 find_include_file (pfile, header, type)
533 const cpp_token *header;
534 enum include_type type;
536 const char *fname = (const char *) header->val.str.text;
537 struct search_path *path;
538 struct include_file *file;
541 if (IS_ABSOLUTE_PATHNAME (fname))
542 return open_file (pfile, fname);
544 /* For #include_next, skip in the search path past the dir in which
545 the current file was found, but if it was found via an absolute
546 path use the normal search logic. */
547 if (type == IT_INCLUDE_NEXT && pfile->buffer->inc->foundhere)
548 path = pfile->buffer->inc->foundhere->next;
549 else if (header->type == CPP_HEADER_NAME)
550 path = CPP_OPTION (pfile, bracket_include);
552 path = search_from (pfile, type);
556 cpp_error (pfile, "No include path in which to find %s", fname);
557 return NO_INCLUDE_PATH;
560 /* Search directory path for the file. */
561 name = (char *) alloca (strlen (fname) + pfile->max_include_len + 2);
562 for (; path; path = path->next)
564 memcpy (name, path->name, path->len);
565 name[path->len] = '/';
566 strcpy (&name[path->len + 1], fname);
567 if (CPP_OPTION (pfile, remap))
568 n = remap_filename (pfile, name, path);
572 file = open_file (pfile, n);
575 file->foundhere = path;
583 /* Not everyone who wants to set system-header-ness on a buffer can
584 see the details of a buffer. This is an exported interface because
585 fix-header needs it. */
587 cpp_make_system_header (pfile, syshdr, externc)
593 /* 1 = system header, 2 = system header to be treated as C. */
595 flags = 1 + (externc != 0);
596 pfile->buffer->sysp = flags;
597 _cpp_do_file_change (pfile, FC_RENAME, pfile->buffer->nominal_fname,
598 pfile->buffer->lineno);
601 /* Report on all files that might benefit from a multiple include guard.
604 _cpp_report_missing_guards (pfile)
608 splay_tree_foreach (pfile->all_include_files, report_missing_guard,
613 report_missing_guard (n, b)
617 struct include_file *f = (struct include_file *) n->value;
618 int *bannerp = (int *)b;
620 if (f && f->cmacro == 0 && f->include_count == 1)
624 fputs (_("Multiple include guards may be useful for:\n"), stderr);
627 fputs (f->name, stderr);
633 /* Create a dependency, or issue an error message as appropriate. */
635 handle_missing_header (pfile, fname, angle_brackets)
640 /* We will try making the RHS pfile->buffer->sysp after 3.0. */
641 int print_dep = CPP_PRINT_DEPS(pfile) > (angle_brackets
642 || pfile->system_include_depth);
644 if (CPP_OPTION (pfile, print_deps_missing_files) && print_dep)
646 if (!angle_brackets || IS_ABSOLUTE_PATHNAME (fname))
647 deps_add_dep (pfile->deps, fname);
650 /* If requested as a system header, assume it belongs in
651 the first system header directory. */
652 struct search_path *ptr = CPP_OPTION (pfile, bracket_include);
654 int len = 0, fname_len = strlen (fname);
659 p = (char *) alloca (len + fname_len + 2);
662 memcpy (p, ptr->name, len);
665 memcpy (p + len, fname, fname_len + 1);
666 deps_add_dep (pfile->deps, p);
669 /* If -M was specified, then don't count this as an error, because
670 we can still produce correct output. Otherwise, we can't produce
671 correct output, because there may be dependencies we need inside
672 the missing file, and we don't know what directory this missing
673 file exists in. FIXME: Use a future cpp_diagnotic_with_errno ()
674 for both of these cases. */
675 else if (CPP_PRINT_DEPS (pfile) && ! print_dep)
676 cpp_warning (pfile, "%s: %s", fname, xstrerror (errno));
678 cpp_error_from_errno (pfile, fname);
681 /* Returns non-zero if a buffer was stacked. */
683 _cpp_execute_include (pfile, header, type)
685 const cpp_token *header;
686 enum include_type type;
688 struct include_file *inc = find_include_file (pfile, header, type);
691 handle_missing_header (pfile, (const char *) header->val.str.text,
692 header->type == CPP_HEADER_NAME);
693 else if (inc != NO_INCLUDE_PATH)
695 if (header->type == CPP_HEADER_NAME)
696 pfile->system_include_depth++;
698 stack_include_file (pfile, inc);
700 if (type == IT_IMPORT)
701 _cpp_never_reread (inc);
709 /* Locate HEADER, and determine whether it is newer than the current
710 file. If it cannot be located or dated, return -1, if it is newer
711 newer, return 1, otherwise 0. */
713 _cpp_compare_file_date (pfile, header)
715 const cpp_token *header;
717 struct include_file *inc = find_include_file (pfile, header, 0);
719 if (inc == NULL || inc == NO_INCLUDE_PATH)
728 return inc->st.st_mtime > pfile->buffer->inc->st.st_mtime;
732 /* Push an input buffer and load it up with the contents of FNAME.
733 If FNAME is "", read standard input. */
735 _cpp_read_file (pfile, fname)
739 struct include_file *f = open_file (pfile, fname);
743 cpp_error_from_errno (pfile, fname);
747 stack_include_file (pfile, f);
751 /* Do appropriate cleanup when a file buffer is popped off the input
754 _cpp_pop_file_buffer (pfile, buf)
758 struct include_file *inc = buf->inc;
760 if (pfile->system_include_depth)
761 pfile->system_include_depth--;
762 if (pfile->include_depth)
763 pfile->include_depth--;
765 /* Record the inclusion-preventing macro, which could be NULL
766 meaning no controlling macro, if we haven't got it already. */
767 if (pfile->mi_state == MI_OUTSIDE && inc->cmacro == NULL)
768 inc->cmacro = pfile->mi_cmacro;
770 /* Invalidate control macros in the #including file. */
771 pfile->mi_state = MI_FAILED;
774 if (inc->refcnt == 0 && DO_NOT_REREAD (inc))
778 /* Returns the first place in the include chain to start searching for
779 "" includes. This involves stripping away the basename of the
780 current file, unless -I- was specified.
782 If we're handling -include or -imacros, use the "" chain, but with
783 the preprocessor's cwd prepended. */
784 static struct search_path *
785 search_from (pfile, type)
787 enum include_type type;
789 cpp_buffer *buffer = pfile->buffer;
792 /* Command line uses the cwd, and does not cache the result. */
793 if (type == IT_CMDLINE)
796 /* Ignore the current file's directory if -I- was given. */
797 if (CPP_OPTION (pfile, ignore_srcdir))
798 return CPP_OPTION (pfile, quote_include);
800 if (! buffer->search_cached)
802 buffer->search_cached = 1;
804 dlen = lbasename (buffer->inc->name) - buffer->inc->name;
808 /* We don't guarantee NAME is null-terminated. This saves
809 allocating and freeing memory, and duplicating it when faking
810 buffers in cpp_push_buffer. Drop a trailing '/'. */
811 buffer->dir.name = buffer->inc->name;
818 buffer->dir.name = ".";
822 if (dlen > pfile->max_include_len)
823 pfile->max_include_len = dlen;
825 buffer->dir.len = dlen;
826 buffer->dir.next = CPP_OPTION (pfile, quote_include);
827 buffer->dir.sysp = buffer->sysp;
833 /* The file_name_map structure holds a mapping of file names for a
834 particular directory. This mapping is read from the file named
835 FILE_NAME_MAP_FILE in that directory. Such a file can be used to
836 map filenames on a file system with severe filename restrictions,
837 such as DOS. The format of the file name map file is just a series
838 of lines with two tokens on each line. The first token is the name
839 to map, and the second token is the actual name to use. */
843 struct file_name_map *map_next;
848 #define FILE_NAME_MAP_FILE "header.gcc"
850 /* Read a space delimited string of unlimited length from a stdio
854 read_filename_string (ch, f)
862 set = alloc = xmalloc (len + 1);
866 while ((ch = getc (f)) != EOF && ! is_space(ch))
868 if (set - alloc == len)
871 alloc = xrealloc (alloc, len + 1);
872 set = alloc + len / 2;
882 /* This structure holds a linked list of file name maps, one per directory. */
884 struct file_name_map_list
886 struct file_name_map_list *map_list_next;
888 struct file_name_map *map_list_map;
891 /* Read the file name map file for DIRNAME. */
893 static struct file_name_map *
894 read_name_map (pfile, dirname)
898 register struct file_name_map_list *map_list_ptr;
902 /* Check the cache of directories, and mappings in their remap file. */
903 for (map_list_ptr = CPP_OPTION (pfile, map_list); map_list_ptr;
904 map_list_ptr = map_list_ptr->map_list_next)
905 if (! strcmp (map_list_ptr->map_list_name, dirname))
906 return map_list_ptr->map_list_map;
908 map_list_ptr = ((struct file_name_map_list *)
909 xmalloc (sizeof (struct file_name_map_list)));
910 map_list_ptr->map_list_name = xstrdup (dirname);
912 /* The end of the list ends in NULL. */
913 map_list_ptr->map_list_map = NULL;
915 name = (char *) alloca (strlen (dirname) + strlen (FILE_NAME_MAP_FILE) + 2);
916 strcpy (name, dirname);
919 strcat (name, FILE_NAME_MAP_FILE);
920 f = fopen (name, "r");
922 /* Silently return NULL if we cannot open. */
926 int dirlen = strlen (dirname);
928 while ((ch = getc (f)) != EOF)
931 struct file_name_map *ptr;
935 from = read_filename_string (ch, f);
936 while ((ch = getc (f)) != EOF && is_hspace(ch))
938 to = read_filename_string (ch, f);
940 ptr = ((struct file_name_map *)
941 xmalloc (sizeof (struct file_name_map)));
942 ptr->map_from = from;
944 /* Make the real filename absolute. */
945 if (IS_ABSOLUTE_PATHNAME (to))
949 ptr->map_to = xmalloc (dirlen + strlen (to) + 2);
950 strcpy (ptr->map_to, dirname);
951 ptr->map_to[dirlen] = '/';
952 strcpy (ptr->map_to + dirlen + 1, to);
956 ptr->map_next = map_list_ptr->map_list_map;
957 map_list_ptr->map_list_map = ptr;
959 while ((ch = getc (f)) != '\n')
966 /* Add this information to the cache. */
967 map_list_ptr->map_list_next = CPP_OPTION (pfile, map_list);
968 CPP_OPTION (pfile, map_list) = map_list_ptr;
970 return map_list_ptr->map_list_map;
973 /* Remap an unsimplified path NAME based on the file_name_map (if any)
976 remap_filename (pfile, name, loc)
979 struct search_path *loc;
981 struct file_name_map *map;
982 const char *from, *p;
987 /* Get a null-terminated path. */
988 char *dname = alloca (loc->len + 1);
989 memcpy (dname, loc->name, loc->len);
990 dname[loc->len] = '\0';
992 loc->name_map = read_name_map (pfile, dname);
997 /* This works since NAME has not been simplified yet. */
998 from = name + loc->len + 1;
1000 for (map = loc->name_map; map; map = map->map_next)
1001 if (!strcmp (map->map_from, from))
1004 /* Try to find a mapping file for the particular directory we are
1005 looking in. Thus #include <sys/types.h> will look up sys/types.h
1006 in /usr/include/header.gcc and look up types.h in
1007 /usr/include/sys/header.gcc. */
1008 p = strrchr (name, '/');
1012 /* We know p != name as absolute paths don't call remap_filename. */
1014 cpp_ice (pfile, "absolute file name in remap_filename");
1016 dir = (char *) alloca (p - name + 1);
1017 memcpy (dir, name, p - name);
1018 dir[p - name] = '\0';
1021 for (map = read_name_map (pfile, dir); map; map = map->map_next)
1022 if (! strcmp (map->map_from, from))
1028 /* Returns true if it is safe to remove the final component of path,
1029 when it is followed by a ".." component. We use lstat to avoid
1030 symlinks if we have it. If not, we can still catch errors with
1033 remove_component_p (path)
1040 result = lstat (path, &s);
1042 result = stat (path, &s);
1045 /* There's no guarantee that errno will be unchanged, even on
1046 success. Cygwin's lstat(), for example, will often set errno to
1047 ENOSYS. In case of success, reset errno to zero. */
1051 return result == 0 && S_ISDIR (s.st_mode);
1054 /* Simplify a path name in place, deleting redundant components. This
1055 reduces OS overhead and guarantees that equivalent paths compare
1056 the same (modulo symlinks).
1059 foo/bar/../quux foo/quux
1063 //quux //quux (POSIX allows leading // as a namespace escape)
1065 Guarantees no trailing slashes. All transforms reduce the length
1066 of the string. Returns PATH. errno is 0 if no error occurred;
1067 nonzero if an error occurred when using stat () or lstat (). */
1070 _cpp_simplify_pathname (path)
1075 char *base, *orig_base;
1079 /* Don't overflow the empty path by putting a '.' in it below. */
1083 #if defined (HAVE_DOS_BASED_FILE_SYSTEM)
1084 /* Convert all backslashes to slashes. */
1085 for (from = path; *from; from++)
1086 if (*from == '\\') *from = '/';
1088 /* Skip over leading drive letter if present. */
1089 if (ISALPHA (path[0]) && path[1] == ':')
1090 from = to = &path[2];
1097 /* Remove redundant leading /s. */
1106 /* 3 or more initial /s are equivalent to 1 /. */
1107 while (*++from == '/');
1109 /* On some hosts // differs from /; Posix allows this. */
1114 base = orig_base = to;
1119 while (*from == '/')
1127 if (from[1] == '\0')
1134 else if (from[1] == '.' && (from[2] == '/' || from[2] == '\0'))
1136 /* Don't simplify if there was no previous component. */
1137 if (absolute && orig_base == to)
1142 /* Don't simplify if the previous component was "../",
1143 or if an error has already occurred with (l)stat. */
1144 if (base != to && errno == 0)
1146 /* We don't back up if it's a symlink. */
1148 if (remove_component_p (path))
1150 while (to > base && *to != '/')
1160 /* Add the component separator. */
1164 /* Copy this component until the trailing null or '/'. */
1165 while (*from != '\0' && *from != '/')
1172 /* Change the empty string to "." so that it is not treated as stdin.