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->map ? pfile->map->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, 0);
333 /* Initialise controlling macro state. */
334 pfile->mi_valid = true;
335 pfile->mi_cmacro = 0;
336 pfile->include_depth++;
338 /* Generate the call back. */
339 _cpp_do_file_change (pfile, LC_ENTER, fp->nominal_fname, 1, sysp);
342 /* Read the file referenced by INC into the file cache.
344 If fd points to a plain file, we might be able to mmap it; we can
345 definitely allocate the buffer all at once. If fd is a pipe or
346 terminal, we can't do either. If fd is something weird, like a
347 block device, we don't want to read it at all.
349 Unfortunately, different systems use different st.st_mode values
350 for pipes: some have S_ISFIFO, some S_ISSOCK, some are buggy and
351 zero the entire struct stat except a couple fields. Hence we don't
352 even try to figure out what something is, except for plain files
355 FIXME: Flush file cache and try again if we run out of memory. */
358 read_include_file (pfile, inc)
360 struct include_file *inc;
362 ssize_t size, offset, count;
365 static int pagesize = -1;
368 if (S_ISREG (inc->st.st_mode))
370 /* off_t might have a wider range than ssize_t - in other words,
371 the max size of a file might be bigger than the address
372 space. We can't handle a file that large. (Anyone with
373 a single source file bigger than 2GB needs to rethink
374 their coding style.) Some systems (e.g. AIX 4.1) define
375 SSIZE_MAX to be much smaller than the actual range of the
376 type. Use INTTYPE_MAXIMUM unconditionally to ensure this
378 if (inc->st.st_size > INTTYPE_MAXIMUM (ssize_t))
380 cpp_error (pfile, "%s is too large", inc->name);
383 size = inc->st.st_size;
388 pagesize = getpagesize ();
390 if (size / pagesize >= MMAP_THRESHOLD)
392 buf = (U_CHAR *) mmap (0, size, PROT_READ, MAP_PRIVATE, inc->fd, 0);
393 if (buf == (U_CHAR *)-1)
400 buf = (U_CHAR *) xmalloc (size);
402 while (offset < size)
404 count = read (inc->fd, buf + offset, size - offset);
409 cpp_warning (pfile, "%s is shorter than expected", inc->name);
416 else if (S_ISBLK (inc->st.st_mode))
418 cpp_error (pfile, "%s is a block device", inc->name);
423 /* 8 kilobytes is a sensible starting size. It ought to be
424 bigger than the kernel pipe buffer, and it's definitely
425 bigger than the majority of C source files. */
428 buf = (U_CHAR *) xmalloc (size);
430 while ((count = read (inc->fd, buf + offset, size - offset)) > 0)
434 buf = xrealloc (buf, (size *= 2));
440 buf = xrealloc (buf, offset);
441 inc->st.st_size = offset;
448 cpp_error_from_errno (pfile, inc->name);
455 struct include_file *inc;
461 munmap ((PTR) inc->buffer, inc->st.st_size);
464 free ((PTR) inc->buffer);
469 /* Return 1 if the file named by FNAME has been included before in
470 any context, 0 otherwise. */
472 cpp_included (pfile, fname)
476 struct search_path *path;
480 if (IS_ABSOLUTE_PATHNAME (fname))
482 /* Just look it up. */
483 nd = splay_tree_lookup (pfile->all_include_files, (splay_tree_key) fname);
484 return (nd && nd->value);
487 /* Search directory path for the file. */
488 name = (char *) alloca (strlen (fname) + pfile->max_include_len + 2);
489 for (path = CPP_OPTION (pfile, quote_include); path; path = path->next)
491 memcpy (name, path->name, path->len);
492 name[path->len] = '/';
493 strcpy (&name[path->len + 1], fname);
494 if (CPP_OPTION (pfile, remap))
495 n = remap_filename (pfile, name, path);
499 nd = splay_tree_lookup (pfile->all_include_files, (splay_tree_key) n);
506 /* Search for HEADER. Return 0 if there is no such file (or it's
507 un-openable), in which case an error code will be in errno. If
508 there is no include path to use it returns NO_INCLUDE_PATH,
509 otherwise an include_file structure. If this request originates
510 from a #include_next directive, set INCLUDE_NEXT to true. */
512 static struct include_file *
513 find_include_file (pfile, header, type)
515 const cpp_token *header;
516 enum include_type type;
518 const char *fname = (const char *) header->val.str.text;
519 struct search_path *path;
520 struct include_file *file;
523 if (IS_ABSOLUTE_PATHNAME (fname))
524 return open_file (pfile, fname);
526 /* For #include_next, skip in the search path past the dir in which
527 the current file was found, but if it was found via an absolute
528 path use the normal search logic. */
529 if (type == IT_INCLUDE_NEXT && pfile->buffer->inc->foundhere)
530 path = pfile->buffer->inc->foundhere->next;
531 else if (header->type == CPP_HEADER_NAME)
532 path = CPP_OPTION (pfile, bracket_include);
534 path = search_from (pfile, type);
538 cpp_error (pfile, "No include path in which to find %s", fname);
539 return NO_INCLUDE_PATH;
542 /* Search directory path for the file. */
543 name = (char *) alloca (strlen (fname) + pfile->max_include_len + 2);
544 for (; path; path = path->next)
546 memcpy (name, path->name, path->len);
547 name[path->len] = '/';
548 strcpy (&name[path->len + 1], fname);
549 if (CPP_OPTION (pfile, remap))
550 n = remap_filename (pfile, name, path);
554 file = open_file (pfile, n);
557 file->foundhere = path;
565 /* Not everyone who wants to set system-header-ness on a buffer can
566 see the details of a buffer. This is an exported interface because
567 fix-header needs it. */
569 cpp_make_system_header (pfile, syshdr, externc)
575 /* 1 = system header, 2 = system header to be treated as C. */
577 flags = 1 + (externc != 0);
578 _cpp_do_file_change (pfile, LC_RENAME, pfile->map->to_file,
579 SOURCE_LINE (pfile->map, pfile->line), flags);
582 /* Report on all files that might benefit from a multiple include guard.
585 _cpp_report_missing_guards (pfile)
589 splay_tree_foreach (pfile->all_include_files, report_missing_guard,
594 report_missing_guard (n, b)
598 struct include_file *f = (struct include_file *) n->value;
599 int *bannerp = (int *)b;
601 if (f && f->cmacro == 0 && f->include_count == 1)
605 fputs (_("Multiple include guards may be useful for:\n"), stderr);
608 fputs (f->name, stderr);
614 /* Create a dependency, or issue an error message as appropriate. */
616 handle_missing_header (pfile, fname, angle_brackets)
621 /* We will try making the RHS pfile->buffer->sysp after 3.0. */
622 int print_dep = CPP_PRINT_DEPS(pfile) > (angle_brackets
623 || pfile->system_include_depth);
625 if (CPP_OPTION (pfile, print_deps_missing_files) && print_dep)
627 if (!angle_brackets || IS_ABSOLUTE_PATHNAME (fname))
628 deps_add_dep (pfile->deps, fname);
631 /* If requested as a system header, assume it belongs in
632 the first system header directory. */
633 struct search_path *ptr = CPP_OPTION (pfile, bracket_include);
635 int len = 0, fname_len = strlen (fname);
640 p = (char *) alloca (len + fname_len + 2);
643 memcpy (p, ptr->name, len);
646 memcpy (p + len, fname, fname_len + 1);
647 deps_add_dep (pfile->deps, p);
650 /* If -M was specified, then don't count this as an error, because
651 we can still produce correct output. Otherwise, we can't produce
652 correct output, because there may be dependencies we need inside
653 the missing file, and we don't know what directory this missing
654 file exists in. FIXME: Use a future cpp_diagnotic_with_errno ()
655 for both of these cases. */
656 else if (CPP_PRINT_DEPS (pfile) && ! print_dep)
657 cpp_warning (pfile, "%s: %s", fname, xstrerror (errno));
659 cpp_error_from_errno (pfile, fname);
662 /* Returns non-zero if a buffer was stacked. */
664 _cpp_execute_include (pfile, header, type)
666 const cpp_token *header;
667 enum include_type type;
669 struct include_file *inc = find_include_file (pfile, header, type);
672 handle_missing_header (pfile, (const char *) header->val.str.text,
673 header->type == CPP_HEADER_NAME);
674 else if (inc != NO_INCLUDE_PATH)
676 if (header->type == CPP_HEADER_NAME)
677 pfile->system_include_depth++;
679 stack_include_file (pfile, inc);
681 if (type == IT_IMPORT)
682 _cpp_never_reread (inc);
690 /* Locate HEADER, and determine whether it is newer than the current
691 file. If it cannot be located or dated, return -1, if it is newer
692 newer, return 1, otherwise 0. */
694 _cpp_compare_file_date (pfile, header)
696 const cpp_token *header;
698 struct include_file *inc = find_include_file (pfile, header, 0);
700 if (inc == NULL || inc == NO_INCLUDE_PATH)
709 return inc->st.st_mtime > pfile->buffer->inc->st.st_mtime;
713 /* Push an input buffer and load it up with the contents of FNAME.
714 If FNAME is "", read standard input. */
716 _cpp_read_file (pfile, fname)
720 struct include_file *f = open_file (pfile, fname);
724 cpp_error_from_errno (pfile, fname);
728 stack_include_file (pfile, f);
732 /* Do appropriate cleanup when a file buffer is popped off the input
735 _cpp_pop_file_buffer (pfile, buf)
739 struct include_file *inc = buf->inc;
741 if (pfile->system_include_depth)
742 pfile->system_include_depth--;
743 if (pfile->include_depth)
744 pfile->include_depth--;
746 /* Record the inclusion-preventing macro, which could be NULL
747 meaning no controlling macro. */
748 if (pfile->mi_valid && inc->cmacro == NULL)
749 inc->cmacro = pfile->mi_cmacro;
751 /* Invalidate control macros in the #including file. */
752 pfile->mi_valid = false;
755 if (inc->refcnt == 0 && DO_NOT_REREAD (inc))
759 /* Returns the first place in the include chain to start searching for
760 "" includes. This involves stripping away the basename of the
761 current file, unless -I- was specified.
763 If we're handling -include or -imacros, use the "" chain, but with
764 the preprocessor's cwd prepended. */
765 static struct search_path *
766 search_from (pfile, type)
768 enum include_type type;
770 cpp_buffer *buffer = pfile->buffer;
773 /* Command line uses the cwd, and does not cache the result. */
774 if (type == IT_CMDLINE)
777 /* Ignore the current file's directory if -I- was given. */
778 if (CPP_OPTION (pfile, ignore_srcdir))
779 return CPP_OPTION (pfile, quote_include);
781 if (! buffer->search_cached)
783 buffer->search_cached = 1;
785 dlen = lbasename (buffer->inc->name) - buffer->inc->name;
789 /* We don't guarantee NAME is null-terminated. This saves
790 allocating and freeing memory, and duplicating it when faking
791 buffers in cpp_push_buffer. Drop a trailing '/'. */
792 buffer->dir.name = buffer->inc->name;
799 buffer->dir.name = ".";
803 if (dlen > pfile->max_include_len)
804 pfile->max_include_len = dlen;
806 buffer->dir.len = dlen;
807 buffer->dir.next = CPP_OPTION (pfile, quote_include);
808 buffer->dir.sysp = pfile->map->sysp;
814 /* The file_name_map structure holds a mapping of file names for a
815 particular directory. This mapping is read from the file named
816 FILE_NAME_MAP_FILE in that directory. Such a file can be used to
817 map filenames on a file system with severe filename restrictions,
818 such as DOS. The format of the file name map file is just a series
819 of lines with two tokens on each line. The first token is the name
820 to map, and the second token is the actual name to use. */
824 struct file_name_map *map_next;
829 #define FILE_NAME_MAP_FILE "header.gcc"
831 /* Read a space delimited string of unlimited length from a stdio
835 read_filename_string (ch, f)
843 set = alloc = xmalloc (len + 1);
847 while ((ch = getc (f)) != EOF && ! is_space(ch))
849 if (set - alloc == len)
852 alloc = xrealloc (alloc, len + 1);
853 set = alloc + len / 2;
863 /* This structure holds a linked list of file name maps, one per directory. */
865 struct file_name_map_list
867 struct file_name_map_list *map_list_next;
869 struct file_name_map *map_list_map;
872 /* Read the file name map file for DIRNAME. */
874 static struct file_name_map *
875 read_name_map (pfile, dirname)
879 register struct file_name_map_list *map_list_ptr;
883 /* Check the cache of directories, and mappings in their remap file. */
884 for (map_list_ptr = CPP_OPTION (pfile, map_list); map_list_ptr;
885 map_list_ptr = map_list_ptr->map_list_next)
886 if (! strcmp (map_list_ptr->map_list_name, dirname))
887 return map_list_ptr->map_list_map;
889 map_list_ptr = ((struct file_name_map_list *)
890 xmalloc (sizeof (struct file_name_map_list)));
891 map_list_ptr->map_list_name = xstrdup (dirname);
893 /* The end of the list ends in NULL. */
894 map_list_ptr->map_list_map = NULL;
896 name = (char *) alloca (strlen (dirname) + strlen (FILE_NAME_MAP_FILE) + 2);
897 strcpy (name, dirname);
900 strcat (name, FILE_NAME_MAP_FILE);
901 f = fopen (name, "r");
903 /* Silently return NULL if we cannot open. */
907 int dirlen = strlen (dirname);
909 while ((ch = getc (f)) != EOF)
912 struct file_name_map *ptr;
916 from = read_filename_string (ch, f);
917 while ((ch = getc (f)) != EOF && is_hspace(ch))
919 to = read_filename_string (ch, f);
921 ptr = ((struct file_name_map *)
922 xmalloc (sizeof (struct file_name_map)));
923 ptr->map_from = from;
925 /* Make the real filename absolute. */
926 if (IS_ABSOLUTE_PATHNAME (to))
930 ptr->map_to = xmalloc (dirlen + strlen (to) + 2);
931 strcpy (ptr->map_to, dirname);
932 ptr->map_to[dirlen] = '/';
933 strcpy (ptr->map_to + dirlen + 1, to);
937 ptr->map_next = map_list_ptr->map_list_map;
938 map_list_ptr->map_list_map = ptr;
940 while ((ch = getc (f)) != '\n')
947 /* Add this information to the cache. */
948 map_list_ptr->map_list_next = CPP_OPTION (pfile, map_list);
949 CPP_OPTION (pfile, map_list) = map_list_ptr;
951 return map_list_ptr->map_list_map;
954 /* Remap an unsimplified path NAME based on the file_name_map (if any)
957 remap_filename (pfile, name, loc)
960 struct search_path *loc;
962 struct file_name_map *map;
963 const char *from, *p;
968 /* Get a null-terminated path. */
969 char *dname = alloca (loc->len + 1);
970 memcpy (dname, loc->name, loc->len);
971 dname[loc->len] = '\0';
973 loc->name_map = read_name_map (pfile, dname);
978 /* This works since NAME has not been simplified yet. */
979 from = name + loc->len + 1;
981 for (map = loc->name_map; map; map = map->map_next)
982 if (!strcmp (map->map_from, from))
985 /* Try to find a mapping file for the particular directory we are
986 looking in. Thus #include <sys/types.h> will look up sys/types.h
987 in /usr/include/header.gcc and look up types.h in
988 /usr/include/sys/header.gcc. */
989 p = strrchr (name, '/');
993 /* We know p != name as absolute paths don't call remap_filename. */
995 cpp_ice (pfile, "absolute file name in remap_filename");
997 dir = (char *) alloca (p - name + 1);
998 memcpy (dir, name, p - name);
999 dir[p - name] = '\0';
1002 for (map = read_name_map (pfile, dir); map; map = map->map_next)
1003 if (! strcmp (map->map_from, from))
1009 /* Returns true if it is safe to remove the final component of path,
1010 when it is followed by a ".." component. We use lstat to avoid
1011 symlinks if we have it. If not, we can still catch errors with
1014 remove_component_p (path)
1021 result = lstat (path, &s);
1023 result = stat (path, &s);
1026 /* There's no guarantee that errno will be unchanged, even on
1027 success. Cygwin's lstat(), for example, will often set errno to
1028 ENOSYS. In case of success, reset errno to zero. */
1032 return result == 0 && S_ISDIR (s.st_mode);
1035 /* Simplify a path name in place, deleting redundant components. This
1036 reduces OS overhead and guarantees that equivalent paths compare
1037 the same (modulo symlinks).
1040 foo/bar/../quux foo/quux
1044 //quux //quux (POSIX allows leading // as a namespace escape)
1046 Guarantees no trailing slashes. All transforms reduce the length
1047 of the string. Returns PATH. errno is 0 if no error occurred;
1048 nonzero if an error occurred when using stat () or lstat (). */
1051 _cpp_simplify_pathname (path)
1056 char *base, *orig_base;
1060 /* Don't overflow the empty path by putting a '.' in it below. */
1064 #if defined (HAVE_DOS_BASED_FILE_SYSTEM)
1065 /* Convert all backslashes to slashes. */
1066 for (from = path; *from; from++)
1067 if (*from == '\\') *from = '/';
1069 /* Skip over leading drive letter if present. */
1070 if (ISALPHA (path[0]) && path[1] == ':')
1071 from = to = &path[2];
1078 /* Remove redundant leading /s. */
1087 /* 3 or more initial /s are equivalent to 1 /. */
1088 while (*++from == '/');
1090 /* On some hosts // differs from /; Posix allows this. */
1095 base = orig_base = to;
1100 while (*from == '/')
1108 if (from[1] == '\0')
1115 else if (from[1] == '.' && (from[2] == '/' || from[2] == '\0'))
1117 /* Don't simplify if there was no previous component. */
1118 if (absolute && orig_base == to)
1123 /* Don't simplify if the previous component was "../",
1124 or if an error has already occurred with (l)stat. */
1125 if (base != to && errno == 0)
1127 /* We don't back up if it's a symlink. */
1129 if (remove_component_p (path))
1131 while (to > base && *to != '/')
1141 /* Add the component separator. */
1145 /* Copy this component until the trailing null or '/'. */
1146 while (*from != '\0' && *from != '/')
1153 /* Change the empty string to "." so that it is not treated as stdin.