1 /* Part of CPP library. (include file handling)
2 Copyright (C) 1986, 1987, 1989, 1992, 1993, 1994, 1995, 1998,
3 1999, 2000, 2001, 2002 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 # define TEST_THRESHOLD(size, pagesize) \
38 (size / pagesize >= MMAP_THRESHOLD && (size % pagesize) != 0)
39 /* Use mmap if the file is big enough to be worth it (controlled
40 by MMAP_THRESHOLD) and if we can safely count on there being
41 at least one readable NUL byte after the end of the file's
42 contents. This is true for all tested operating systems when
43 the file size is not an exact multiple of the page size. */
45 # define SHOULD_MMAP(size, pagesize) TEST_THRESHOLD (size, pagesize)
47 # define WIN32_LEAN_AND_MEAN
49 /* Cygwin can't correctly emulate mmap under Windows 9x style systems so
50 disallow use of mmap on those systems. Windows 9x does not zero fill
51 memory at EOF and beyond, as required. */
52 # define SHOULD_MMAP(size, pagesize) ((GetVersion() & 0x80000000) \
53 ? 0 : TEST_THRESHOLD (size, pagesize))
57 #else /* No MMAP_FILE */
58 # undef MMAP_THRESHOLD
59 # define MMAP_THRESHOLD 0
66 /* If errno is inspected immediately after a system call fails, it will be
67 nonzero, and no error number will ever be zero. */
75 /* Suppress warning about function macros used w/o arguments in traditional
76 C. It is unlikely that glibc's strcmp macro helps this file at all. */
79 /* This structure is used for the table of all includes. */
81 const char *name; /* actual path name of file */
82 const cpp_hashnode *cmacro; /* macro, if any, preventing reinclusion. */
83 const struct search_path *foundhere;
84 /* location in search path where file was
85 found, for #include_next and sysp. */
86 const unsigned char *buffer; /* pointer to cached file contents */
87 struct stat st; /* copy of stat(2) data for file */
88 int fd; /* fd open on file (short term storage only) */
89 int err_no; /* errno obtained if opening a file failed */
90 unsigned short include_count; /* number of times file has been read */
91 unsigned short refcnt; /* number of stacked buffers using this file */
92 unsigned char mapped; /* file buffer is mmapped */
95 /* Variable length record files on VMS will have a stat size that includes
96 record control characters that won't be included in the read size. */
98 # define FAB_C_VAR 2 /* variable length records (see Starlet fabdef.h) */
99 # define STAT_SIZE_TOO_BIG(ST) ((ST).st_fab_rfm == FAB_C_VAR)
101 # define STAT_SIZE_TOO_BIG(ST) 0
104 /* The cmacro works like this: If it's NULL, the file is to be
105 included again. If it's NEVER_REREAD, the file is never to be
106 included again. Otherwise it is a macro hashnode, and the file is
107 to be included again if the macro is defined. */
108 #define NEVER_REREAD ((const cpp_hashnode *) -1)
109 #define DO_NOT_REREAD(inc) \
110 ((inc)->cmacro && ((inc)->cmacro == NEVER_REREAD \
111 || (inc)->cmacro->type == NT_MACRO))
112 #define NO_INCLUDE_PATH ((struct include_file *) -1)
114 static struct file_name_map *read_name_map
115 PARAMS ((cpp_reader *, const char *));
116 static char *read_filename_string PARAMS ((int, FILE *));
117 static char *remap_filename PARAMS ((cpp_reader *, char *,
118 struct search_path *));
119 static struct search_path *search_from PARAMS ((cpp_reader *,
121 static struct include_file *
122 find_include_file PARAMS ((cpp_reader *, const cpp_token *,
124 static struct include_file *open_file PARAMS ((cpp_reader *, const char *));
125 static int read_include_file PARAMS ((cpp_reader *, struct include_file *));
126 static bool stack_include_file PARAMS ((cpp_reader *, struct include_file *));
127 static void purge_cache PARAMS ((struct include_file *));
128 static void destroy_node PARAMS ((splay_tree_value));
129 static int report_missing_guard PARAMS ((splay_tree_node, void *));
130 static splay_tree_node find_or_create_entry PARAMS ((cpp_reader *,
132 static void handle_missing_header PARAMS ((cpp_reader *, const char *, int));
133 static int remove_component_p PARAMS ((const char *));
135 /* Set up the splay tree we use to store information about all the
136 file names seen in this compilation. We also have entries for each
137 file we tried to open but failed; this saves system calls since we
138 don't try to open it again in future.
140 The key of each node is the file name, after processing by
141 _cpp_simplify_pathname. The path name may or may not be absolute.
142 The path string has been malloced, as is automatically freed by
143 registering free () as the splay tree key deletion function.
145 A node's value is a pointer to a struct include_file, and is never
148 _cpp_init_includes (pfile)
151 pfile->all_include_files
152 = splay_tree_new ((splay_tree_compare_fn) strcmp,
153 (splay_tree_delete_key_fn) free,
157 /* Tear down the splay tree. */
159 _cpp_cleanup_includes (pfile)
162 splay_tree_delete (pfile->all_include_files);
165 /* Free a node. The path string is automatically freed. */
170 struct include_file *f = (struct include_file *) v;
179 /* Mark a file to not be reread (e.g. #import, read failure). */
181 _cpp_never_reread (file)
182 struct include_file *file;
184 file->cmacro = NEVER_REREAD;
187 /* Lookup a filename, which is simplified after making a copy, and
188 create an entry if none exists. errno is nonzero iff a (reported)
189 stat() error occurred during simplification. */
190 static splay_tree_node
191 find_or_create_entry (pfile, fname)
195 splay_tree_node node;
196 struct include_file *file;
197 char *name = xstrdup (fname);
199 _cpp_simplify_pathname (name);
200 node = splay_tree_lookup (pfile->all_include_files, (splay_tree_key) name);
205 file = xcnew (struct include_file);
207 file->err_no = errno;
208 node = splay_tree_insert (pfile->all_include_files,
209 (splay_tree_key) file->name,
210 (splay_tree_value) file);
216 /* Enter a file name in the splay tree, for the sake of cpp_included. */
218 _cpp_fake_include (pfile, fname)
222 find_or_create_entry (pfile, fname);
225 /* Given a file name, look it up in the cache; if there is no entry,
226 create one with a non-NULL value (regardless of success in opening
227 the file). If the file doesn't exist or is inaccessible, this
228 entry is flagged so we don't attempt to open it again in the
229 future. If the file isn't open, open it. The empty string is
230 interpreted as stdin.
232 Returns an include_file structure with an open file descriptor on
233 success, or NULL on failure. */
234 static struct include_file *
235 open_file (pfile, filename)
237 const char *filename;
239 splay_tree_node nd = find_or_create_entry (pfile, filename);
240 struct include_file *file = (struct include_file *) nd->value;
244 /* Ugh. handle_missing_header () needs errno to be set. */
245 errno = file->err_no;
249 /* Don't reopen an idempotent file. */
250 if (DO_NOT_REREAD (file))
253 /* Don't reopen one which is already loaded. */
254 if (file->buffer != NULL)
257 /* We used to open files in nonblocking mode, but that caused more
258 problems than it solved. Do take care not to acquire a
259 controlling terminal by mistake (this can't happen on sane
260 systems, but paranoia is a virtue).
262 Use the three-argument form of open even though we aren't
263 specifying O_CREAT, to defend against broken system headers.
265 O_BINARY tells some runtime libraries (notably DJGPP) not to do
266 newline translation; we can handle DOS line breaks just fine
269 Special case: the empty string is translated to stdin. */
271 if (filename[0] == '\0')
275 /* For DJGPP redirected input is opened in text mode. Change it
277 if (! isatty (file->fd))
278 setmode (file->fd, O_BINARY);
282 file->fd = open (file->name, O_RDONLY | O_NOCTTY | O_BINARY, 0666);
284 if (file->fd != -1 && fstat (file->fd, &file->st) == 0)
286 if (!S_ISDIR (file->st.st_mode))
289 /* If it's a directory, we return null and continue the search
290 as the file we're looking for may appear elsewhere in the
297 file->err_no = errno;
301 /* Place the file referenced by INC into a new buffer on the buffer
302 stack, unless there are errors, or the file is not re-included
303 because of e.g. multiple-include guards. Returns true if a buffer
306 stack_include_file (pfile, inc)
308 struct include_file *inc;
312 const char *filename;
314 if (DO_NOT_REREAD (inc))
317 sysp = MAX ((pfile->map ? pfile->map->sysp : 0),
318 (inc->foundhere ? inc->foundhere->sysp : 0));
320 /* Add the file to the dependencies on its first inclusion. */
321 if (CPP_OPTION (pfile, deps.style) > !!sysp && !inc->include_count)
323 if (pfile->buffer || CPP_OPTION (pfile, deps.ignore_main_file) == 0)
324 deps_add_dep (pfile->deps, inc->name);
330 if (read_include_file (pfile, inc))
332 /* If an error occurs, do not try to read this file again. */
333 _cpp_never_reread (inc);
336 /* Mark a regular, zero-length file never-reread. We read it,
337 NUL-terminate it, and stack it once, so preprocessing a main
338 file of zero length does not raise an error. */
339 if (S_ISREG (inc->st.st_mode) && inc->st.st_size == 0)
340 _cpp_never_reread (inc);
346 /* We don't want MI guard advice for the main file. */
347 inc->include_count++;
350 fp = cpp_push_buffer (pfile, inc->buffer, inc->st.st_size,
351 /* from_stage3 */ CPP_OPTION (pfile, preprocessed), 0);
355 /* Initialize controlling macro state. */
356 pfile->mi_valid = true;
357 pfile->mi_cmacro = 0;
359 /* Generate the call back. */
360 filename = inc->name;
361 if (*filename == '\0')
362 filename = "<stdin>";
363 _cpp_do_file_change (pfile, LC_ENTER, filename, 1, sysp);
368 /* Read the file referenced by INC into the file cache.
370 If fd points to a plain file, we might be able to mmap it; we can
371 definitely allocate the buffer all at once. If fd is a pipe or
372 terminal, we can't do either. If fd is something weird, like a
373 block device, we don't want to read it at all.
375 Unfortunately, different systems use different st.st_mode values
376 for pipes: some have S_ISFIFO, some S_ISSOCK, some are buggy and
377 zero the entire struct stat except a couple fields. Hence we don't
378 even try to figure out what something is, except for plain files
381 FIXME: Flush file cache and try again if we run out of memory. */
383 read_include_file (pfile, inc)
385 struct include_file *inc;
387 ssize_t size, offset, count;
390 static int pagesize = -1;
393 if (S_ISREG (inc->st.st_mode))
395 /* off_t might have a wider range than ssize_t - in other words,
396 the max size of a file might be bigger than the address
397 space. We can't handle a file that large. (Anyone with
398 a single source file bigger than 2GB needs to rethink
399 their coding style.) Some systems (e.g. AIX 4.1) define
400 SSIZE_MAX to be much smaller than the actual range of the
401 type. Use INTTYPE_MAXIMUM unconditionally to ensure this
403 if (inc->st.st_size > INTTYPE_MAXIMUM (ssize_t))
405 cpp_error (pfile, DL_ERROR, "%s is too large", inc->name);
408 size = inc->st.st_size;
413 pagesize = getpagesize ();
415 if (SHOULD_MMAP (size, pagesize))
417 buf = (uchar *) mmap (0, size, PROT_READ, MAP_PRIVATE, inc->fd, 0);
418 if (buf == (uchar *) -1)
425 buf = (uchar *) xmalloc (size + 1);
427 while (offset < size)
429 count = read (inc->fd, buf + offset, size - offset);
434 if (!STAT_SIZE_TOO_BIG (inc->st))
435 cpp_error (pfile, DL_WARNING,
436 "%s is shorter than expected", inc->name);
438 buf = xrealloc (buf, size + 1);
439 inc->st.st_size = size;
444 /* The lexer requires that the buffer be NUL-terminated. */
448 else if (S_ISBLK (inc->st.st_mode))
450 cpp_error (pfile, DL_ERROR, "%s is a block device", inc->name);
455 /* 8 kilobytes is a sensible starting size. It ought to be
456 bigger than the kernel pipe buffer, and it's definitely
457 bigger than the majority of C source files. */
460 buf = (uchar *) xmalloc (size + 1);
462 while ((count = read (inc->fd, buf + offset, size - offset)) > 0)
468 buf = xrealloc (buf, size + 1);
474 if (offset + 1 < size)
475 buf = xrealloc (buf, offset + 1);
477 /* The lexer requires that the buffer be NUL-terminated. */
479 inc->st.st_size = offset;
486 cpp_errno (pfile, DL_ERROR, inc->name);
491 /* Drop INC's buffer from memory, if we are unlikely to need it again. */
494 struct include_file *inc;
500 munmap ((PTR) inc->buffer, inc->st.st_size);
503 free ((PTR) inc->buffer);
508 /* Return 1 if the file named by FNAME has been included before in
509 any context, 0 otherwise. */
511 cpp_included (pfile, fname)
515 struct search_path *path;
519 if (IS_ABSOLUTE_PATHNAME (fname))
521 /* Just look it up. */
522 nd = splay_tree_lookup (pfile->all_include_files, (splay_tree_key) fname);
523 return (nd && nd->value);
526 /* Search directory path for the file. */
527 name = (char *) alloca (strlen (fname) + pfile->max_include_len + 2);
528 for (path = CPP_OPTION (pfile, quote_include); path; path = path->next)
530 memcpy (name, path->name, path->len);
531 name[path->len] = '/';
532 strcpy (&name[path->len + 1], fname);
533 if (CPP_OPTION (pfile, remap))
534 n = remap_filename (pfile, name, path);
538 nd = splay_tree_lookup (pfile->all_include_files, (splay_tree_key) n);
545 /* Search for HEADER. Return 0 if there is no such file (or it's
546 un-openable), in which case an error code will be in errno. If
547 there is no include path to use it returns NO_INCLUDE_PATH,
548 otherwise an include_file structure. If this request originates
549 from a directive of TYPE #include_next, set INCLUDE_NEXT to true. */
550 static struct include_file *
551 find_include_file (pfile, header, type)
553 const cpp_token *header;
554 enum include_type type;
556 const char *fname = (const char *) header->val.str.text;
557 struct search_path *path;
558 struct include_file *file;
561 if (IS_ABSOLUTE_PATHNAME (fname))
562 return open_file (pfile, fname);
564 /* For #include_next, skip in the search path past the dir in which
565 the current file was found, but if it was found via an absolute
566 path use the normal search logic. */
567 if (type == IT_INCLUDE_NEXT && pfile->buffer->inc->foundhere)
568 path = pfile->buffer->inc->foundhere->next;
569 else if (header->type == CPP_HEADER_NAME)
570 path = CPP_OPTION (pfile, bracket_include);
572 path = search_from (pfile, type);
576 cpp_error (pfile, DL_ERROR, "no include path in which to find %s",
578 return NO_INCLUDE_PATH;
581 /* Search directory path for the file. */
582 name = (char *) alloca (strlen (fname) + pfile->max_include_len + 2);
583 for (; path; path = path->next)
586 memcpy (name, path->name, len);
587 /* Don't turn / into // or // into ///; // may be a namespace
589 if (name[len-1] == '/')
592 strcpy (&name[len + 1], fname);
593 if (CPP_OPTION (pfile, remap))
594 n = remap_filename (pfile, name, path);
598 file = open_file (pfile, n);
601 file->foundhere = path;
609 /* Not everyone who wants to set system-header-ness on a buffer can
610 see the details of a buffer. This is an exported interface because
611 fix-header needs it. */
613 cpp_make_system_header (pfile, syshdr, externc)
619 /* 1 = system header, 2 = system header to be treated as C. */
621 flags = 1 + (externc != 0);
622 _cpp_do_file_change (pfile, LC_RENAME, pfile->map->to_file,
623 SOURCE_LINE (pfile->map, pfile->line), flags);
626 /* Report on all files that might benefit from a multiple include guard.
629 _cpp_report_missing_guards (pfile)
633 splay_tree_foreach (pfile->all_include_files, report_missing_guard,
637 /* Callback function for splay_tree_foreach(). */
639 report_missing_guard (n, b)
643 struct include_file *f = (struct include_file *) n->value;
644 int *bannerp = (int *) b;
646 if (f && f->cmacro == 0 && f->include_count == 1)
650 fputs (_("Multiple include guards may be useful for:\n"), stderr);
653 fputs (f->name, stderr);
659 /* Create a dependency for file FNAME, or issue an error message as
660 appropriate. ANGLE_BRACKETS is nonzero if the file was bracketed
663 handle_missing_header (pfile, fname, angle_brackets)
669 = CPP_OPTION (pfile, deps.style) > (angle_brackets || pfile->map->sysp);
671 if (CPP_OPTION (pfile, deps.missing_files) && print_dep)
672 deps_add_dep (pfile->deps, fname);
673 /* If -M was specified, then don't count this as an error, because
674 we can still produce correct output. Otherwise, we can't produce
675 correct output, because there may be dependencies we need inside
676 the missing file, and we don't know what directory this missing
679 cpp_errno (pfile, CPP_OPTION (pfile, deps.style) && ! print_dep
680 ? DL_WARNING: DL_ERROR, fname);
683 /* Handles #include-family directives (distinguished by TYPE),
684 including HEADER, and the command line -imacros and -include.
685 Returns true if a buffer was stacked. */
687 _cpp_execute_include (pfile, header, type)
689 const cpp_token *header;
690 enum include_type type;
692 bool stacked = false;
693 struct include_file *inc = find_include_file (pfile, header, type);
696 handle_missing_header (pfile, (const char *) header->val.str.text,
697 header->type == CPP_HEADER_NAME);
698 else if (inc != NO_INCLUDE_PATH)
700 stacked = stack_include_file (pfile, inc);
702 if (type == IT_IMPORT)
703 _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. If
733 FNAME is "", read standard input. Return true if a buffer was
736 _cpp_read_file (pfile, fname)
740 struct include_file *f = open_file (pfile, fname);
744 cpp_errno (pfile, DL_ERROR, fname);
748 return stack_include_file (pfile, f);
751 /* Do appropriate cleanup when a file INC's buffer is popped off the
754 _cpp_pop_file_buffer (pfile, inc)
756 struct include_file *inc;
758 /* Record the inclusion-preventing macro, which could be NULL
759 meaning no controlling macro. */
760 if (pfile->mi_valid && inc->cmacro == NULL)
761 inc->cmacro = pfile->mi_cmacro;
763 /* Invalidate control macros in the #including file. */
764 pfile->mi_valid = false;
767 if (inc->refcnt == 0 && DO_NOT_REREAD (inc))
771 /* Returns the first place in the include chain to start searching for
772 "" includes. This involves stripping away the basename of the
773 current file, unless -I- was specified.
775 If we're handling -include or -imacros, use the "" chain, but with
776 the preprocessor's cwd prepended. */
777 static struct search_path *
778 search_from (pfile, type)
780 enum include_type type;
782 cpp_buffer *buffer = pfile->buffer;
785 /* Command line uses the cwd, and does not cache the result. */
786 if (type == IT_CMDLINE)
789 /* Ignore the current file's directory if -I- was given. */
790 if (CPP_OPTION (pfile, ignore_srcdir))
791 return CPP_OPTION (pfile, quote_include);
793 if (! buffer->search_cached)
795 buffer->search_cached = 1;
797 dlen = lbasename (buffer->inc->name) - buffer->inc->name;
801 /* We don't guarantee NAME is null-terminated. This saves
802 allocating and freeing memory. Drop a trailing '/'. */
803 buffer->dir.name = buffer->inc->name;
810 buffer->dir.name = ".";
814 if (dlen > pfile->max_include_len)
815 pfile->max_include_len = dlen;
817 buffer->dir.len = dlen;
818 buffer->dir.next = CPP_OPTION (pfile, quote_include);
819 buffer->dir.sysp = pfile->map->sysp;
825 /* The file_name_map structure holds a mapping of file names for a
826 particular directory. This mapping is read from the file named
827 FILE_NAME_MAP_FILE in that directory. Such a file can be used to
828 map filenames on a file system with severe filename restrictions,
829 such as DOS. The format of the file name map file is just a series
830 of lines with two tokens on each line. The first token is the name
831 to map, and the second token is the actual name to use. */
832 struct file_name_map {
833 struct file_name_map *map_next;
838 #define FILE_NAME_MAP_FILE "header.gcc"
840 /* Read a space delimited string of unlimited length from a stdio
843 read_filename_string (ch, f)
851 set = alloc = xmalloc (len + 1);
855 while ((ch = getc (f)) != EOF && ! is_space (ch))
857 if (set - alloc == len)
860 alloc = xrealloc (alloc, len + 1);
861 set = alloc + len / 2;
871 /* This structure holds a linked list of file name maps, one per directory. */
872 struct file_name_map_list {
873 struct file_name_map_list *map_list_next;
875 struct file_name_map *map_list_map;
878 /* Read the file name map file for DIRNAME. */
879 static struct file_name_map *
880 read_name_map (pfile, dirname)
884 struct file_name_map_list *map_list_ptr;
888 /* Check the cache of directories, and mappings in their remap file. */
889 for (map_list_ptr = CPP_OPTION (pfile, map_list); map_list_ptr;
890 map_list_ptr = map_list_ptr->map_list_next)
891 if (! strcmp (map_list_ptr->map_list_name, dirname))
892 return map_list_ptr->map_list_map;
894 map_list_ptr = ((struct file_name_map_list *)
895 xmalloc (sizeof (struct file_name_map_list)));
896 map_list_ptr->map_list_name = xstrdup (dirname);
898 /* The end of the list ends in NULL. */
899 map_list_ptr->map_list_map = NULL;
901 name = (char *) alloca (strlen (dirname) + strlen (FILE_NAME_MAP_FILE) + 2);
902 strcpy (name, dirname);
905 strcat (name, FILE_NAME_MAP_FILE);
906 f = fopen (name, "r");
908 /* Silently return NULL if we cannot open. */
913 while ((ch = getc (f)) != EOF)
916 struct file_name_map *ptr;
920 from = read_filename_string (ch, f);
921 while ((ch = getc (f)) != EOF && is_hspace (ch))
923 to = read_filename_string (ch, f);
925 ptr = ((struct file_name_map *)
926 xmalloc (sizeof (struct file_name_map)));
927 ptr->map_from = from;
929 /* Make the real filename absolute. */
930 if (IS_ABSOLUTE_PATHNAME (to))
934 ptr->map_to = concat (dirname, "/", to, NULL);
938 ptr->map_next = map_list_ptr->map_list_map;
939 map_list_ptr->map_list_map = ptr;
941 while ((ch = getc (f)) != '\n')
948 /* Add this information to the cache. */
949 map_list_ptr->map_list_next = CPP_OPTION (pfile, map_list);
950 CPP_OPTION (pfile, map_list) = map_list_ptr;
952 return map_list_ptr->map_list_map;
955 /* Remap an unsimplified path NAME based on the file_name_map (if any)
958 remap_filename (pfile, name, loc)
961 struct search_path *loc;
963 struct file_name_map *map;
964 const char *from, *p;
969 /* Get a null-terminated path. */
970 char *dname = alloca (loc->len + 1);
971 memcpy (dname, loc->name, loc->len);
972 dname[loc->len] = '\0';
974 loc->name_map = read_name_map (pfile, dname);
979 /* This works since NAME has not been simplified yet. */
980 from = name + loc->len + 1;
982 for (map = loc->name_map; map; map = map->map_next)
983 if (!strcmp (map->map_from, from))
986 /* Try to find a mapping file for the particular directory we are
987 looking in. Thus #include <sys/types.h> will look up sys/types.h
988 in /usr/include/header.gcc and look up types.h in
989 /usr/include/sys/header.gcc. */
990 p = strrchr (name, '/');
994 /* We know p != name as absolute paths don't call remap_filename. */
996 cpp_error (pfile, DL_ICE, "absolute file name in remap_filename");
998 dir = (char *) alloca (p - name + 1);
999 memcpy (dir, name, p - name);
1000 dir[p - name] = '\0';
1003 for (map = read_name_map (pfile, dir); map; map = map->map_next)
1004 if (! strcmp (map->map_from, from))
1010 /* Returns true if it is safe to remove the final component of path,
1011 when it is followed by a ".." component. We use lstat to avoid
1012 symlinks if we have it. If not, we can still catch errors with
1015 remove_component_p (path)
1022 result = lstat (path, &s);
1024 result = stat (path, &s);
1027 /* There's no guarantee that errno will be unchanged, even on
1028 success. Cygwin's lstat(), for example, will often set errno to
1029 ENOSYS. In case of success, reset errno to zero. */
1033 return result == 0 && S_ISDIR (s.st_mode);
1036 /* Simplify a path name in place, deleting redundant components. This
1037 reduces OS overhead and guarantees that equivalent paths compare
1038 the same (modulo symlinks).
1041 foo/bar/../quux foo/quux
1045 //quux //quux (POSIX allows leading // as a namespace escape)
1047 Guarantees no trailing slashes. All transforms reduce the length
1048 of the string. Returns PATH. errno is 0 if no error occurred;
1049 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.