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 /* Variable length record files on VMS will have a stat size that includes
77 record control characters that won't be included in the read size. */
79 # define FAB_C_VAR 2 /* variable length records (see Starlet fabdef.h) */
80 # define STAT_SIZE_TOO_BIG(ST) ((ST).st_fab_rfm == FAB_C_VAR)
82 # define STAT_SIZE_TOO_BIG(ST) 0
85 /* The cmacro works like this: If it's NULL, the file is to be
86 included again. If it's NEVER_REREAD, the file is never to be
87 included again. Otherwise it is a macro hashnode, and the file is
88 to be included again if the macro is defined. */
89 #define NEVER_REREAD ((const cpp_hashnode *)-1)
90 #define DO_NOT_REREAD(inc) \
91 ((inc)->cmacro && ((inc)->cmacro == NEVER_REREAD \
92 || (inc)->cmacro->type == NT_MACRO))
93 #define NO_INCLUDE_PATH ((struct include_file *) -1)
95 static struct file_name_map *read_name_map
96 PARAMS ((cpp_reader *, const char *));
97 static char *read_filename_string PARAMS ((int, FILE *));
98 static char *remap_filename PARAMS ((cpp_reader *, char *,
99 struct search_path *));
100 static struct search_path *search_from PARAMS ((cpp_reader *,
102 static struct include_file *
103 find_include_file PARAMS ((cpp_reader *, const cpp_token *,
105 static struct include_file *open_file PARAMS ((cpp_reader *, const char *));
106 static int read_include_file PARAMS ((cpp_reader *, struct include_file *));
107 static bool stack_include_file PARAMS ((cpp_reader *, struct include_file *));
108 static void purge_cache PARAMS ((struct include_file *));
109 static void destroy_node PARAMS ((splay_tree_value));
110 static int report_missing_guard PARAMS ((splay_tree_node, void *));
111 static splay_tree_node find_or_create_entry PARAMS ((cpp_reader *,
113 static void handle_missing_header PARAMS ((cpp_reader *, const char *, int));
114 static int remove_component_p PARAMS ((const char *));
116 /* Set up the splay tree we use to store information about all the
117 file names seen in this compilation. We also have entries for each
118 file we tried to open but failed; this saves system calls since we
119 don't try to open it again in future.
121 The key of each node is the file name, after processing by
122 _cpp_simplify_pathname. The path name may or may not be absolute.
123 The path string has been malloced, as is automatically freed by
124 registering free () as the splay tree key deletion function.
126 A node's value is a pointer to a struct include_file, and is never
129 _cpp_init_includes (pfile)
132 pfile->all_include_files
133 = splay_tree_new ((splay_tree_compare_fn) strcmp,
134 (splay_tree_delete_key_fn) free,
138 /* Tear down the splay tree. */
140 _cpp_cleanup_includes (pfile)
143 splay_tree_delete (pfile->all_include_files);
146 /* Free a node. The path string is automatically freed. */
151 struct include_file *f = (struct include_file *)v;
160 /* Mark a file to not be reread (e.g. #import, read failure). */
162 _cpp_never_reread (file)
163 struct include_file *file;
165 file->cmacro = NEVER_REREAD;
168 /* Lookup a filename, which is simplified after making a copy, and
169 create an entry if none exists. errno is nonzero iff a (reported)
170 stat() error occurred during simplification. */
171 static splay_tree_node
172 find_or_create_entry (pfile, fname)
176 splay_tree_node node;
177 struct include_file *file;
178 char *name = xstrdup (fname);
180 _cpp_simplify_pathname (name);
181 node = splay_tree_lookup (pfile->all_include_files, (splay_tree_key) name);
186 file = xcnew (struct include_file);
188 file->err_no = errno;
189 node = splay_tree_insert (pfile->all_include_files,
190 (splay_tree_key) file->name,
191 (splay_tree_value) file);
197 /* Enter a file name in the splay tree, for the sake of cpp_included. */
199 _cpp_fake_include (pfile, fname)
203 find_or_create_entry (pfile, fname);
206 /* Given a file name, look it up in the cache; if there is no entry,
207 create one with a non-NULL value (regardless of success in opening
208 the file). If the file doesn't exist or is inaccessible, this
209 entry is flagged so we don't attempt to open it again in the
210 future. If the file isn't open, open it. The empty string is
211 interpreted as stdin.
213 Returns an include_file structure with an open file descriptor on
214 success, or NULL on failure. */
216 static struct include_file *
217 open_file (pfile, filename)
219 const char *filename;
221 splay_tree_node nd = find_or_create_entry (pfile, filename);
222 struct include_file *file = (struct include_file *) nd->value;
226 /* Ugh. handle_missing_header () needs errno to be set. */
227 errno = file->err_no;
231 /* Don't reopen an idempotent file. */
232 if (DO_NOT_REREAD (file))
235 /* Don't reopen one which is already loaded. */
236 if (file->buffer != NULL)
239 /* We used to open files in nonblocking mode, but that caused more
240 problems than it solved. Do take care not to acquire a
241 controlling terminal by mistake (this can't happen on sane
242 systems, but paranoia is a virtue).
244 Use the three-argument form of open even though we aren't
245 specifying O_CREAT, to defend against broken system headers.
247 O_BINARY tells some runtime libraries (notably DJGPP) not to do
248 newline translation; we can handle DOS line breaks just fine
251 Special case: the empty string is translated to stdin. */
253 if (filename[0] == '\0')
256 file->fd = open (file->name, O_RDONLY | O_NOCTTY | O_BINARY, 0666);
258 if (file->fd != -1 && fstat (file->fd, &file->st) == 0)
260 if (!S_ISDIR (file->st.st_mode))
262 /* If it's a directory, we return null and continue the search
263 as the file we're looking for may appear elsewhere in the
268 file->err_no = errno;
272 /* Place the file referenced by INC into a new buffer on the buffer
273 stack, unless there are errors, or the file is not re-included
274 because of e.g. multiple-include guards. Returns true if a buffer
278 stack_include_file (pfile, inc)
280 struct include_file *inc;
284 const char *filename;
286 if (DO_NOT_REREAD (inc))
289 sysp = MAX ((pfile->map ? pfile->map->sysp : 0),
290 (inc->foundhere ? inc->foundhere->sysp : 0));
292 /* For -M, add the file to the dependencies on its first inclusion. */
293 if (CPP_OPTION (pfile, print_deps) > sysp && !inc->include_count)
294 deps_add_dep (pfile->deps, inc->name);
299 /* Mark a regular, zero-length file never-reread. Zero-length
300 files are stacked the first time, so preprocessing a main
301 file of zero length does not raise an error. */
302 if (S_ISREG (inc->st.st_mode) && inc->st.st_size == 0)
303 _cpp_never_reread (inc);
304 else if (read_include_file (pfile, inc))
306 /* If an error occurs, do not try to read this file again. */
307 _cpp_never_reread (inc);
315 /* We don't want MI guard advice for the main file. */
316 inc->include_count++;
319 fp = cpp_push_buffer (pfile, inc->buffer, inc->st.st_size,
320 /* from_stage3 */ CPP_OPTION (pfile, preprocessed), 0);
324 /* Initialise controlling macro state. */
325 pfile->mi_valid = true;
326 pfile->mi_cmacro = 0;
328 /* Generate the call back. */
329 filename = inc->name;
330 if (*filename == '\0')
331 filename = _("<stdin>");
332 _cpp_do_file_change (pfile, LC_ENTER, filename, 1, sysp);
337 /* Read the file referenced by INC into the file cache.
339 If fd points to a plain file, we might be able to mmap it; we can
340 definitely allocate the buffer all at once. If fd is a pipe or
341 terminal, we can't do either. If fd is something weird, like a
342 block device, we don't want to read it at all.
344 Unfortunately, different systems use different st.st_mode values
345 for pipes: some have S_ISFIFO, some S_ISSOCK, some are buggy and
346 zero the entire struct stat except a couple fields. Hence we don't
347 even try to figure out what something is, except for plain files
350 FIXME: Flush file cache and try again if we run out of memory. */
353 read_include_file (pfile, inc)
355 struct include_file *inc;
357 ssize_t size, offset, count;
360 static int pagesize = -1;
363 if (S_ISREG (inc->st.st_mode))
365 /* off_t might have a wider range than ssize_t - in other words,
366 the max size of a file might be bigger than the address
367 space. We can't handle a file that large. (Anyone with
368 a single source file bigger than 2GB needs to rethink
369 their coding style.) Some systems (e.g. AIX 4.1) define
370 SSIZE_MAX to be much smaller than the actual range of the
371 type. Use INTTYPE_MAXIMUM unconditionally to ensure this
373 if (inc->st.st_size > INTTYPE_MAXIMUM (ssize_t))
375 cpp_error (pfile, "%s is too large", inc->name);
378 size = inc->st.st_size;
383 pagesize = getpagesize ();
385 if (size / pagesize >= MMAP_THRESHOLD)
387 buf = (U_CHAR *) mmap (0, size, PROT_READ, MAP_PRIVATE, inc->fd, 0);
388 if (buf == (U_CHAR *)-1)
395 buf = (U_CHAR *) xmalloc (size);
397 while (offset < size)
399 count = read (inc->fd, buf + offset, size - offset);
404 if (!STAT_SIZE_TOO_BIG (inc->st))
406 (pfile, "%s is shorter than expected", inc->name);
407 buf = xrealloc (buf, offset);
408 inc->st.st_size = offset;
415 else if (S_ISBLK (inc->st.st_mode))
417 cpp_error (pfile, "%s is a block device", inc->name);
422 /* 8 kilobytes is a sensible starting size. It ought to be
423 bigger than the kernel pipe buffer, and it's definitely
424 bigger than the majority of C source files. */
427 buf = (U_CHAR *) xmalloc (size);
429 while ((count = read (inc->fd, buf + offset, size - offset)) > 0)
433 buf = xrealloc (buf, (size *= 2));
439 buf = xrealloc (buf, offset);
440 inc->st.st_size = offset;
447 cpp_error_from_errno (pfile, inc->name);
454 struct include_file *inc;
460 munmap ((PTR) inc->buffer, inc->st.st_size);
463 free ((PTR) inc->buffer);
468 /* Return 1 if the file named by FNAME has been included before in
469 any context, 0 otherwise. */
471 cpp_included (pfile, fname)
475 struct search_path *path;
479 if (IS_ABSOLUTE_PATHNAME (fname))
481 /* Just look it up. */
482 nd = splay_tree_lookup (pfile->all_include_files, (splay_tree_key) fname);
483 return (nd && nd->value);
486 /* Search directory path for the file. */
487 name = (char *) alloca (strlen (fname) + pfile->max_include_len + 2);
488 for (path = CPP_OPTION (pfile, quote_include); path; path = path->next)
490 memcpy (name, path->name, path->len);
491 name[path->len] = '/';
492 strcpy (&name[path->len + 1], fname);
493 if (CPP_OPTION (pfile, remap))
494 n = remap_filename (pfile, name, path);
498 nd = splay_tree_lookup (pfile->all_include_files, (splay_tree_key) n);
505 /* Search for HEADER. Return 0 if there is no such file (or it's
506 un-openable), in which case an error code will be in errno. If
507 there is no include path to use it returns NO_INCLUDE_PATH,
508 otherwise an include_file structure. If this request originates
509 from a #include_next directive, set INCLUDE_NEXT to true. */
511 static struct include_file *
512 find_include_file (pfile, header, type)
514 const cpp_token *header;
515 enum include_type type;
517 const char *fname = (const char *) header->val.str.text;
518 struct search_path *path;
519 struct include_file *file;
522 if (IS_ABSOLUTE_PATHNAME (fname))
523 return open_file (pfile, fname);
525 /* For #include_next, skip in the search path past the dir in which
526 the current file was found, but if it was found via an absolute
527 path use the normal search logic. */
528 if (type == IT_INCLUDE_NEXT && pfile->buffer->inc->foundhere)
529 path = pfile->buffer->inc->foundhere->next;
530 else if (header->type == CPP_HEADER_NAME)
531 path = CPP_OPTION (pfile, bracket_include);
533 path = search_from (pfile, type);
537 cpp_error (pfile, "No include path in which to find %s", fname);
538 return NO_INCLUDE_PATH;
541 /* Search directory path for the file. */
542 name = (char *) alloca (strlen (fname) + pfile->max_include_len + 2);
543 for (; path; path = path->next)
545 memcpy (name, path->name, path->len);
546 name[path->len] = '/';
547 strcpy (&name[path->len + 1], fname);
548 if (CPP_OPTION (pfile, remap))
549 n = remap_filename (pfile, name, path);
553 file = open_file (pfile, n);
556 file->foundhere = path;
564 /* Not everyone who wants to set system-header-ness on a buffer can
565 see the details of a buffer. This is an exported interface because
566 fix-header needs it. */
568 cpp_make_system_header (pfile, syshdr, externc)
574 /* 1 = system header, 2 = system header to be treated as C. */
576 flags = 1 + (externc != 0);
577 _cpp_do_file_change (pfile, LC_RENAME, pfile->map->to_file,
578 SOURCE_LINE (pfile->map, pfile->line), flags);
581 /* Report on all files that might benefit from a multiple include guard.
584 _cpp_report_missing_guards (pfile)
588 splay_tree_foreach (pfile->all_include_files, report_missing_guard,
593 report_missing_guard (n, b)
597 struct include_file *f = (struct include_file *) n->value;
598 int *bannerp = (int *)b;
600 if (f && f->cmacro == 0 && f->include_count == 1)
604 fputs (_("Multiple include guards may be useful for:\n"), stderr);
607 fputs (f->name, stderr);
613 /* Create a dependency, or issue an error message as appropriate. */
615 handle_missing_header (pfile, fname, angle_brackets)
620 int print_dep = CPP_PRINT_DEPS(pfile) > (angle_brackets || pfile->map->sysp);
622 if (CPP_OPTION (pfile, print_deps_missing_files) && print_dep)
624 if (!angle_brackets || IS_ABSOLUTE_PATHNAME (fname))
625 deps_add_dep (pfile->deps, fname);
628 /* If requested as a system header, assume it belongs in
629 the first system header directory. */
630 struct search_path *ptr = CPP_OPTION (pfile, bracket_include);
632 int len = 0, fname_len = strlen (fname);
637 p = (char *) alloca (len + fname_len + 2);
640 memcpy (p, ptr->name, len);
643 memcpy (p + len, fname, fname_len + 1);
644 deps_add_dep (pfile->deps, p);
647 /* If -M was specified, then don't count this as an error, because
648 we can still produce correct output. Otherwise, we can't produce
649 correct output, because there may be dependencies we need inside
650 the missing file, and we don't know what directory this missing
651 file exists in. FIXME: Use a future cpp_diagnostic_with_errno ()
652 for both of these cases. */
653 else if (CPP_PRINT_DEPS (pfile) && ! print_dep)
654 cpp_warning (pfile, "%s: %s", fname, xstrerror (errno));
656 cpp_error_from_errno (pfile, fname);
659 /* Handles #include-family directives, and the command line -imacros
660 and -include. Returns true if a buffer was stacked. */
662 _cpp_execute_include (pfile, header, type)
664 const cpp_token *header;
665 enum include_type type;
667 bool stacked = false;
668 struct include_file *inc = find_include_file (pfile, header, type);
671 handle_missing_header (pfile, (const char *) header->val.str.text,
672 header->type == CPP_HEADER_NAME);
673 else if (inc != NO_INCLUDE_PATH)
675 stacked = stack_include_file (pfile, inc);
677 if (type == IT_IMPORT)
678 _cpp_never_reread (inc);
684 /* Locate HEADER, and determine whether it is newer than the current
685 file. If it cannot be located or dated, return -1, if it is newer
686 newer, return 1, otherwise 0. */
688 _cpp_compare_file_date (pfile, header)
690 const cpp_token *header;
692 struct include_file *inc = find_include_file (pfile, header, 0);
694 if (inc == NULL || inc == NO_INCLUDE_PATH)
703 return inc->st.st_mtime > pfile->buffer->inc->st.st_mtime;
707 /* Push an input buffer and load it up with the contents of FNAME. If
708 FNAME is "", read standard input. Return true if a buffer was
711 _cpp_read_file (pfile, fname)
715 struct include_file *f = open_file (pfile, fname);
719 cpp_error_from_errno (pfile, fname);
723 return stack_include_file (pfile, f);
726 /* Do appropriate cleanup when a file buffer is popped off the input
727 stack. Push the next -include file, if any remain. */
729 _cpp_pop_file_buffer (pfile, inc)
731 struct include_file *inc;
733 /* Record the inclusion-preventing macro, which could be NULL
734 meaning no controlling macro. */
735 if (pfile->mi_valid && inc->cmacro == NULL)
736 inc->cmacro = pfile->mi_cmacro;
738 /* Invalidate control macros in the #including file. */
739 pfile->mi_valid = false;
742 if (inc->refcnt == 0 && DO_NOT_REREAD (inc))
745 /* Don't generate a callback for popping the main file. */
748 _cpp_do_file_change (pfile, LC_LEAVE, 0, 0, 0);
750 /* Finally, push the next -included file, if any. */
751 if (!pfile->buffer->prev)
752 _cpp_push_next_buffer (pfile);
756 /* Returns the first place in the include chain to start searching for
757 "" includes. This involves stripping away the basename of the
758 current file, unless -I- was specified.
760 If we're handling -include or -imacros, use the "" chain, but with
761 the preprocessor's cwd prepended. */
762 static struct search_path *
763 search_from (pfile, type)
765 enum include_type type;
767 cpp_buffer *buffer = pfile->buffer;
770 /* Command line uses the cwd, and does not cache the result. */
771 if (type == IT_CMDLINE)
774 /* Ignore the current file's directory if -I- was given. */
775 if (CPP_OPTION (pfile, ignore_srcdir))
776 return CPP_OPTION (pfile, quote_include);
778 if (! buffer->search_cached)
780 buffer->search_cached = 1;
782 dlen = lbasename (buffer->inc->name) - buffer->inc->name;
786 /* We don't guarantee NAME is null-terminated. This saves
787 allocating and freeing memory. Drop a trailing '/'. */
788 buffer->dir.name = buffer->inc->name;
795 buffer->dir.name = ".";
799 if (dlen > pfile->max_include_len)
800 pfile->max_include_len = dlen;
802 buffer->dir.len = dlen;
803 buffer->dir.next = CPP_OPTION (pfile, quote_include);
804 buffer->dir.sysp = pfile->map->sysp;
810 /* The file_name_map structure holds a mapping of file names for a
811 particular directory. This mapping is read from the file named
812 FILE_NAME_MAP_FILE in that directory. Such a file can be used to
813 map filenames on a file system with severe filename restrictions,
814 such as DOS. The format of the file name map file is just a series
815 of lines with two tokens on each line. The first token is the name
816 to map, and the second token is the actual name to use. */
820 struct file_name_map *map_next;
825 #define FILE_NAME_MAP_FILE "header.gcc"
827 /* Read a space delimited string of unlimited length from a stdio
831 read_filename_string (ch, f)
839 set = alloc = xmalloc (len + 1);
843 while ((ch = getc (f)) != EOF && ! is_space(ch))
845 if (set - alloc == len)
848 alloc = xrealloc (alloc, len + 1);
849 set = alloc + len / 2;
859 /* This structure holds a linked list of file name maps, one per directory. */
861 struct file_name_map_list
863 struct file_name_map_list *map_list_next;
865 struct file_name_map *map_list_map;
868 /* Read the file name map file for DIRNAME. */
870 static struct file_name_map *
871 read_name_map (pfile, dirname)
875 struct file_name_map_list *map_list_ptr;
879 /* Check the cache of directories, and mappings in their remap file. */
880 for (map_list_ptr = CPP_OPTION (pfile, map_list); map_list_ptr;
881 map_list_ptr = map_list_ptr->map_list_next)
882 if (! strcmp (map_list_ptr->map_list_name, dirname))
883 return map_list_ptr->map_list_map;
885 map_list_ptr = ((struct file_name_map_list *)
886 xmalloc (sizeof (struct file_name_map_list)));
887 map_list_ptr->map_list_name = xstrdup (dirname);
889 /* The end of the list ends in NULL. */
890 map_list_ptr->map_list_map = NULL;
892 name = (char *) alloca (strlen (dirname) + strlen (FILE_NAME_MAP_FILE) + 2);
893 strcpy (name, dirname);
896 strcat (name, FILE_NAME_MAP_FILE);
897 f = fopen (name, "r");
899 /* Silently return NULL if we cannot open. */
903 int dirlen = strlen (dirname);
905 while ((ch = getc (f)) != EOF)
908 struct file_name_map *ptr;
912 from = read_filename_string (ch, f);
913 while ((ch = getc (f)) != EOF && is_hspace(ch))
915 to = read_filename_string (ch, f);
917 ptr = ((struct file_name_map *)
918 xmalloc (sizeof (struct file_name_map)));
919 ptr->map_from = from;
921 /* Make the real filename absolute. */
922 if (IS_ABSOLUTE_PATHNAME (to))
926 ptr->map_to = xmalloc (dirlen + strlen (to) + 2);
927 strcpy (ptr->map_to, dirname);
928 ptr->map_to[dirlen] = '/';
929 strcpy (ptr->map_to + dirlen + 1, to);
933 ptr->map_next = map_list_ptr->map_list_map;
934 map_list_ptr->map_list_map = ptr;
936 while ((ch = getc (f)) != '\n')
943 /* Add this information to the cache. */
944 map_list_ptr->map_list_next = CPP_OPTION (pfile, map_list);
945 CPP_OPTION (pfile, map_list) = map_list_ptr;
947 return map_list_ptr->map_list_map;
950 /* Remap an unsimplified path NAME based on the file_name_map (if any)
953 remap_filename (pfile, name, loc)
956 struct search_path *loc;
958 struct file_name_map *map;
959 const char *from, *p;
964 /* Get a null-terminated path. */
965 char *dname = alloca (loc->len + 1);
966 memcpy (dname, loc->name, loc->len);
967 dname[loc->len] = '\0';
969 loc->name_map = read_name_map (pfile, dname);
974 /* This works since NAME has not been simplified yet. */
975 from = name + loc->len + 1;
977 for (map = loc->name_map; map; map = map->map_next)
978 if (!strcmp (map->map_from, from))
981 /* Try to find a mapping file for the particular directory we are
982 looking in. Thus #include <sys/types.h> will look up sys/types.h
983 in /usr/include/header.gcc and look up types.h in
984 /usr/include/sys/header.gcc. */
985 p = strrchr (name, '/');
989 /* We know p != name as absolute paths don't call remap_filename. */
991 cpp_ice (pfile, "absolute file name in remap_filename");
993 dir = (char *) alloca (p - name + 1);
994 memcpy (dir, name, p - name);
995 dir[p - name] = '\0';
998 for (map = read_name_map (pfile, dir); map; map = map->map_next)
999 if (! strcmp (map->map_from, from))
1005 /* Returns true if it is safe to remove the final component of path,
1006 when it is followed by a ".." component. We use lstat to avoid
1007 symlinks if we have it. If not, we can still catch errors with
1010 remove_component_p (path)
1017 result = lstat (path, &s);
1019 result = stat (path, &s);
1022 /* There's no guarantee that errno will be unchanged, even on
1023 success. Cygwin's lstat(), for example, will often set errno to
1024 ENOSYS. In case of success, reset errno to zero. */
1028 return result == 0 && S_ISDIR (s.st_mode);
1031 /* Simplify a path name in place, deleting redundant components. This
1032 reduces OS overhead and guarantees that equivalent paths compare
1033 the same (modulo symlinks).
1036 foo/bar/../quux foo/quux
1040 //quux //quux (POSIX allows leading // as a namespace escape)
1042 Guarantees no trailing slashes. All transforms reduce the length
1043 of the string. Returns PATH. errno is 0 if no error occurred;
1044 nonzero if an error occurred when using stat () or lstat (). */
1047 _cpp_simplify_pathname (path)
1052 char *base, *orig_base;
1056 /* Don't overflow the empty path by putting a '.' in it below. */
1060 #if defined (HAVE_DOS_BASED_FILE_SYSTEM)
1061 /* Convert all backslashes to slashes. */
1062 for (from = path; *from; from++)
1063 if (*from == '\\') *from = '/';
1065 /* Skip over leading drive letter if present. */
1066 if (ISALPHA (path[0]) && path[1] == ':')
1067 from = to = &path[2];
1074 /* Remove redundant leading /s. */
1083 /* 3 or more initial /s are equivalent to 1 /. */
1084 while (*++from == '/');
1086 /* On some hosts // differs from /; Posix allows this. */
1091 base = orig_base = to;
1096 while (*from == '/')
1104 if (from[1] == '\0')
1111 else if (from[1] == '.' && (from[2] == '/' || from[2] == '\0'))
1113 /* Don't simplify if there was no previous component. */
1114 if (absolute && orig_base == to)
1119 /* Don't simplify if the previous component was "../",
1120 or if an error has already occurred with (l)stat. */
1121 if (base != to && errno == 0)
1123 /* We don't back up if it's a symlink. */
1125 if (remove_component_p (path))
1127 while (to > base && *to != '/')
1137 /* Add the component separator. */
1141 /* Copy this component until the trailing null or '/'. */
1142 while (*from != '\0' && *from != '/')
1149 /* Change the empty string to "." so that it is not treated as stdin.