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, 0);
334 /* Initialise controlling macro state. */
335 pfile->mi_valid = true;
336 pfile->mi_cmacro = 0;
337 pfile->include_depth++;
339 /* Generate the call back. */
340 _cpp_do_file_change (pfile, LC_ENTER, 1);
343 /* Read the file referenced by INC into the file cache.
345 If fd points to a plain file, we might be able to mmap it; we can
346 definitely allocate the buffer all at once. If fd is a pipe or
347 terminal, we can't do either. If fd is something weird, like a
348 block device, we don't want to read it at all.
350 Unfortunately, different systems use different st.st_mode values
351 for pipes: some have S_ISFIFO, some S_ISSOCK, some are buggy and
352 zero the entire struct stat except a couple fields. Hence we don't
353 even try to figure out what something is, except for plain files
356 FIXME: Flush file cache and try again if we run out of memory. */
359 read_include_file (pfile, inc)
361 struct include_file *inc;
363 ssize_t size, offset, count;
366 static int pagesize = -1;
369 if (S_ISREG (inc->st.st_mode))
371 /* off_t might have a wider range than ssize_t - in other words,
372 the max size of a file might be bigger than the address
373 space. We can't handle a file that large. (Anyone with
374 a single source file bigger than 2GB needs to rethink
375 their coding style.) Some systems (e.g. AIX 4.1) define
376 SSIZE_MAX to be much smaller than the actual range of the
377 type. Use INTTYPE_MAXIMUM unconditionally to ensure this
379 if (inc->st.st_size > INTTYPE_MAXIMUM (ssize_t))
381 cpp_error (pfile, "%s is too large", inc->name);
384 size = inc->st.st_size;
389 pagesize = getpagesize ();
391 if (size / pagesize >= MMAP_THRESHOLD)
393 buf = (U_CHAR *) mmap (0, size, PROT_READ, MAP_PRIVATE, inc->fd, 0);
394 if (buf == (U_CHAR *)-1)
401 buf = (U_CHAR *) xmalloc (size);
403 while (offset < size)
405 count = read (inc->fd, buf + offset, size - offset);
410 cpp_warning (pfile, "%s is shorter than expected", inc->name);
417 else if (S_ISBLK (inc->st.st_mode))
419 cpp_error (pfile, "%s is a block device", inc->name);
424 /* 8 kilobytes is a sensible starting size. It ought to be
425 bigger than the kernel pipe buffer, and it's definitely
426 bigger than the majority of C source files. */
429 buf = (U_CHAR *) xmalloc (size);
431 while ((count = read (inc->fd, buf + offset, size - offset)) > 0)
435 buf = xrealloc (buf, (size *= 2));
441 buf = xrealloc (buf, offset);
442 inc->st.st_size = offset;
449 cpp_error_from_errno (pfile, inc->name);
456 struct include_file *inc;
462 munmap ((PTR) inc->buffer, inc->st.st_size);
465 free ((PTR) inc->buffer);
470 /* Return 1 if the file named by FNAME has been included before in
471 any context, 0 otherwise. */
473 cpp_included (pfile, fname)
477 struct search_path *path;
481 if (IS_ABSOLUTE_PATHNAME (fname))
483 /* Just look it up. */
484 nd = splay_tree_lookup (pfile->all_include_files, (splay_tree_key) fname);
485 return (nd && nd->value);
488 /* Search directory path for the file. */
489 name = (char *) alloca (strlen (fname) + pfile->max_include_len + 2);
490 for (path = CPP_OPTION (pfile, quote_include); path; path = path->next)
492 memcpy (name, path->name, path->len);
493 name[path->len] = '/';
494 strcpy (&name[path->len + 1], fname);
495 if (CPP_OPTION (pfile, remap))
496 n = remap_filename (pfile, name, path);
500 nd = splay_tree_lookup (pfile->all_include_files, (splay_tree_key) n);
507 /* Search for HEADER. Return 0 if there is no such file (or it's
508 un-openable), in which case an error code will be in errno. If
509 there is no include path to use it returns NO_INCLUDE_PATH,
510 otherwise an include_file structure. If this request originates
511 from a #include_next directive, set INCLUDE_NEXT to true. */
513 static struct include_file *
514 find_include_file (pfile, header, type)
516 const cpp_token *header;
517 enum include_type type;
519 const char *fname = (const char *) header->val.str.text;
520 struct search_path *path;
521 struct include_file *file;
524 if (IS_ABSOLUTE_PATHNAME (fname))
525 return open_file (pfile, fname);
527 /* For #include_next, skip in the search path past the dir in which
528 the current file was found, but if it was found via an absolute
529 path use the normal search logic. */
530 if (type == IT_INCLUDE_NEXT && pfile->buffer->inc->foundhere)
531 path = pfile->buffer->inc->foundhere->next;
532 else if (header->type == CPP_HEADER_NAME)
533 path = CPP_OPTION (pfile, bracket_include);
535 path = search_from (pfile, type);
539 cpp_error (pfile, "No include path in which to find %s", fname);
540 return NO_INCLUDE_PATH;
543 /* Search directory path for the file. */
544 name = (char *) alloca (strlen (fname) + pfile->max_include_len + 2);
545 for (; path; path = path->next)
547 memcpy (name, path->name, path->len);
548 name[path->len] = '/';
549 strcpy (&name[path->len + 1], fname);
550 if (CPP_OPTION (pfile, remap))
551 n = remap_filename (pfile, name, path);
555 file = open_file (pfile, n);
558 file->foundhere = path;
566 /* Not everyone who wants to set system-header-ness on a buffer can
567 see the details of a buffer. This is an exported interface because
568 fix-header needs it. */
570 cpp_make_system_header (pfile, syshdr, externc)
576 /* 1 = system header, 2 = system header to be treated as C. */
578 flags = 1 + (externc != 0);
579 pfile->buffer->sysp = flags;
580 _cpp_do_file_change (pfile, LC_RENAME,
581 SOURCE_LINE (pfile->map, pfile->line));
584 /* Report on all files that might benefit from a multiple include guard.
587 _cpp_report_missing_guards (pfile)
591 splay_tree_foreach (pfile->all_include_files, report_missing_guard,
596 report_missing_guard (n, b)
600 struct include_file *f = (struct include_file *) n->value;
601 int *bannerp = (int *)b;
603 if (f && f->cmacro == 0 && f->include_count == 1)
607 fputs (_("Multiple include guards may be useful for:\n"), stderr);
610 fputs (f->name, stderr);
616 /* Create a dependency, or issue an error message as appropriate. */
618 handle_missing_header (pfile, fname, angle_brackets)
623 /* We will try making the RHS pfile->buffer->sysp after 3.0. */
624 int print_dep = CPP_PRINT_DEPS(pfile) > (angle_brackets
625 || pfile->system_include_depth);
627 if (CPP_OPTION (pfile, print_deps_missing_files) && print_dep)
629 if (!angle_brackets || IS_ABSOLUTE_PATHNAME (fname))
630 deps_add_dep (pfile->deps, fname);
633 /* If requested as a system header, assume it belongs in
634 the first system header directory. */
635 struct search_path *ptr = CPP_OPTION (pfile, bracket_include);
637 int len = 0, fname_len = strlen (fname);
642 p = (char *) alloca (len + fname_len + 2);
645 memcpy (p, ptr->name, len);
648 memcpy (p + len, fname, fname_len + 1);
649 deps_add_dep (pfile->deps, p);
652 /* If -M was specified, then don't count this as an error, because
653 we can still produce correct output. Otherwise, we can't produce
654 correct output, because there may be dependencies we need inside
655 the missing file, and we don't know what directory this missing
656 file exists in. FIXME: Use a future cpp_diagnotic_with_errno ()
657 for both of these cases. */
658 else if (CPP_PRINT_DEPS (pfile) && ! print_dep)
659 cpp_warning (pfile, "%s: %s", fname, xstrerror (errno));
661 cpp_error_from_errno (pfile, fname);
664 /* Returns non-zero if a buffer was stacked. */
666 _cpp_execute_include (pfile, header, type)
668 const cpp_token *header;
669 enum include_type type;
671 struct include_file *inc = find_include_file (pfile, header, type);
674 handle_missing_header (pfile, (const char *) header->val.str.text,
675 header->type == CPP_HEADER_NAME);
676 else if (inc != NO_INCLUDE_PATH)
678 if (header->type == CPP_HEADER_NAME)
679 pfile->system_include_depth++;
681 pfile->buffer->return_to_line = SOURCE_LINE (pfile->map, pfile->line);
682 stack_include_file (pfile, inc);
684 if (type == IT_IMPORT)
685 _cpp_never_reread (inc);
693 /* Locate HEADER, and determine whether it is newer than the current
694 file. If it cannot be located or dated, return -1, if it is newer
695 newer, return 1, otherwise 0. */
697 _cpp_compare_file_date (pfile, header)
699 const cpp_token *header;
701 struct include_file *inc = find_include_file (pfile, header, 0);
703 if (inc == NULL || inc == NO_INCLUDE_PATH)
712 return inc->st.st_mtime > pfile->buffer->inc->st.st_mtime;
716 /* Push an input buffer and load it up with the contents of FNAME.
717 If FNAME is "", read standard input. */
719 _cpp_read_file (pfile, fname)
723 struct include_file *f = open_file (pfile, fname);
727 cpp_error_from_errno (pfile, fname);
731 stack_include_file (pfile, f);
735 /* Do appropriate cleanup when a file buffer is popped off the input
738 _cpp_pop_file_buffer (pfile, buf)
742 struct include_file *inc = buf->inc;
744 if (pfile->system_include_depth)
745 pfile->system_include_depth--;
746 if (pfile->include_depth)
747 pfile->include_depth--;
749 /* Record the inclusion-preventing macro, which could be NULL
750 meaning no controlling macro. */
751 if (pfile->mi_valid && inc->cmacro == NULL)
752 inc->cmacro = pfile->mi_cmacro;
754 /* Invalidate control macros in the #including file. */
755 pfile->mi_valid = false;
758 if (inc->refcnt == 0 && DO_NOT_REREAD (inc))
762 /* Returns the first place in the include chain to start searching for
763 "" includes. This involves stripping away the basename of the
764 current file, unless -I- was specified.
766 If we're handling -include or -imacros, use the "" chain, but with
767 the preprocessor's cwd prepended. */
768 static struct search_path *
769 search_from (pfile, type)
771 enum include_type type;
773 cpp_buffer *buffer = pfile->buffer;
776 /* Command line uses the cwd, and does not cache the result. */
777 if (type == IT_CMDLINE)
780 /* Ignore the current file's directory if -I- was given. */
781 if (CPP_OPTION (pfile, ignore_srcdir))
782 return CPP_OPTION (pfile, quote_include);
784 if (! buffer->search_cached)
786 buffer->search_cached = 1;
788 dlen = lbasename (buffer->inc->name) - buffer->inc->name;
792 /* We don't guarantee NAME is null-terminated. This saves
793 allocating and freeing memory, and duplicating it when faking
794 buffers in cpp_push_buffer. Drop a trailing '/'. */
795 buffer->dir.name = buffer->inc->name;
802 buffer->dir.name = ".";
806 if (dlen > pfile->max_include_len)
807 pfile->max_include_len = dlen;
809 buffer->dir.len = dlen;
810 buffer->dir.next = CPP_OPTION (pfile, quote_include);
811 buffer->dir.sysp = buffer->sysp;
817 /* The file_name_map structure holds a mapping of file names for a
818 particular directory. This mapping is read from the file named
819 FILE_NAME_MAP_FILE in that directory. Such a file can be used to
820 map filenames on a file system with severe filename restrictions,
821 such as DOS. The format of the file name map file is just a series
822 of lines with two tokens on each line. The first token is the name
823 to map, and the second token is the actual name to use. */
827 struct file_name_map *map_next;
832 #define FILE_NAME_MAP_FILE "header.gcc"
834 /* Read a space delimited string of unlimited length from a stdio
838 read_filename_string (ch, f)
846 set = alloc = xmalloc (len + 1);
850 while ((ch = getc (f)) != EOF && ! is_space(ch))
852 if (set - alloc == len)
855 alloc = xrealloc (alloc, len + 1);
856 set = alloc + len / 2;
866 /* This structure holds a linked list of file name maps, one per directory. */
868 struct file_name_map_list
870 struct file_name_map_list *map_list_next;
872 struct file_name_map *map_list_map;
875 /* Read the file name map file for DIRNAME. */
877 static struct file_name_map *
878 read_name_map (pfile, dirname)
882 register struct file_name_map_list *map_list_ptr;
886 /* Check the cache of directories, and mappings in their remap file. */
887 for (map_list_ptr = CPP_OPTION (pfile, map_list); map_list_ptr;
888 map_list_ptr = map_list_ptr->map_list_next)
889 if (! strcmp (map_list_ptr->map_list_name, dirname))
890 return map_list_ptr->map_list_map;
892 map_list_ptr = ((struct file_name_map_list *)
893 xmalloc (sizeof (struct file_name_map_list)));
894 map_list_ptr->map_list_name = xstrdup (dirname);
896 /* The end of the list ends in NULL. */
897 map_list_ptr->map_list_map = NULL;
899 name = (char *) alloca (strlen (dirname) + strlen (FILE_NAME_MAP_FILE) + 2);
900 strcpy (name, dirname);
903 strcat (name, FILE_NAME_MAP_FILE);
904 f = fopen (name, "r");
906 /* Silently return NULL if we cannot open. */
910 int dirlen = strlen (dirname);
912 while ((ch = getc (f)) != EOF)
915 struct file_name_map *ptr;
919 from = read_filename_string (ch, f);
920 while ((ch = getc (f)) != EOF && is_hspace(ch))
922 to = read_filename_string (ch, f);
924 ptr = ((struct file_name_map *)
925 xmalloc (sizeof (struct file_name_map)));
926 ptr->map_from = from;
928 /* Make the real filename absolute. */
929 if (IS_ABSOLUTE_PATHNAME (to))
933 ptr->map_to = xmalloc (dirlen + strlen (to) + 2);
934 strcpy (ptr->map_to, dirname);
935 ptr->map_to[dirlen] = '/';
936 strcpy (ptr->map_to + dirlen + 1, to);
940 ptr->map_next = map_list_ptr->map_list_map;
941 map_list_ptr->map_list_map = ptr;
943 while ((ch = getc (f)) != '\n')
950 /* Add this information to the cache. */
951 map_list_ptr->map_list_next = CPP_OPTION (pfile, map_list);
952 CPP_OPTION (pfile, map_list) = map_list_ptr;
954 return map_list_ptr->map_list_map;
957 /* Remap an unsimplified path NAME based on the file_name_map (if any)
960 remap_filename (pfile, name, loc)
963 struct search_path *loc;
965 struct file_name_map *map;
966 const char *from, *p;
971 /* Get a null-terminated path. */
972 char *dname = alloca (loc->len + 1);
973 memcpy (dname, loc->name, loc->len);
974 dname[loc->len] = '\0';
976 loc->name_map = read_name_map (pfile, dname);
981 /* This works since NAME has not been simplified yet. */
982 from = name + loc->len + 1;
984 for (map = loc->name_map; map; map = map->map_next)
985 if (!strcmp (map->map_from, from))
988 /* Try to find a mapping file for the particular directory we are
989 looking in. Thus #include <sys/types.h> will look up sys/types.h
990 in /usr/include/header.gcc and look up types.h in
991 /usr/include/sys/header.gcc. */
992 p = strrchr (name, '/');
996 /* We know p != name as absolute paths don't call remap_filename. */
998 cpp_ice (pfile, "absolute file name in remap_filename");
1000 dir = (char *) alloca (p - name + 1);
1001 memcpy (dir, name, p - name);
1002 dir[p - name] = '\0';
1005 for (map = read_name_map (pfile, dir); map; map = map->map_next)
1006 if (! strcmp (map->map_from, from))
1012 /* Returns true if it is safe to remove the final component of path,
1013 when it is followed by a ".." component. We use lstat to avoid
1014 symlinks if we have it. If not, we can still catch errors with
1017 remove_component_p (path)
1024 result = lstat (path, &s);
1026 result = stat (path, &s);
1029 /* There's no guarantee that errno will be unchanged, even on
1030 success. Cygwin's lstat(), for example, will often set errno to
1031 ENOSYS. In case of success, reset errno to zero. */
1035 return result == 0 && S_ISDIR (s.st_mode);
1038 /* Simplify a path name in place, deleting redundant components. This
1039 reduces OS overhead and guarantees that equivalent paths compare
1040 the same (modulo symlinks).
1043 foo/bar/../quux foo/quux
1047 //quux //quux (POSIX allows leading // as a namespace escape)
1049 Guarantees no trailing slashes. All transforms reduce the length
1050 of the string. Returns PATH. errno is 0 if no error occurred;
1051 nonzero if an error occurred when using stat () or lstat (). */
1054 _cpp_simplify_pathname (path)
1059 char *base, *orig_base;
1063 /* Don't overflow the empty path by putting a '.' in it below. */
1067 #if defined (HAVE_DOS_BASED_FILE_SYSTEM)
1068 /* Convert all backslashes to slashes. */
1069 for (from = path; *from; from++)
1070 if (*from == '\\') *from = '/';
1072 /* Skip over leading drive letter if present. */
1073 if (ISALPHA (path[0]) && path[1] == ':')
1074 from = to = &path[2];
1081 /* Remove redundant leading /s. */
1090 /* 3 or more initial /s are equivalent to 1 /. */
1091 while (*++from == '/');
1093 /* On some hosts // differs from /; Posix allows this. */
1098 base = orig_base = to;
1103 while (*from == '/')
1111 if (from[1] == '\0')
1118 else if (from[1] == '.' && (from[2] == '/' || from[2] == '\0'))
1120 /* Don't simplify if there was no previous component. */
1121 if (absolute && orig_base == to)
1126 /* Don't simplify if the previous component was "../",
1127 or if an error has already occurred with (l)stat. */
1128 if (base != to && errno == 0)
1130 /* We don't back up if it's a symlink. */
1132 if (remove_component_p (path))
1134 while (to > base && *to != '/')
1144 /* Add the component separator. */
1148 /* Copy this component until the trailing null or '/'. */
1149 while (*from != '\0' && *from != '/')
1156 /* Change the empty string to "." so that it is not treated as stdin.