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 #ifndef INCLUDE_LEN_FUDGE
47 # define INCLUDE_LEN_FUDGE 0
50 /* If errno is inspected immediately after a system call fails, it will be
51 nonzero, and no error number will ever be zero. */
62 /* Suppress warning about function macros used w/o arguments in traditional
63 C. It is unlikely that glibc's strcmp macro helps this file at all. */
66 /* This structure is used for the table of all includes. */
69 const char *name; /* actual path name of file */
70 const cpp_hashnode *cmacro; /* macro, if any, preventing reinclusion. */
71 const struct file_name_list *foundhere;
72 /* location in search path where file was
73 found, for #include_next and sysp. */
74 const unsigned char *buffer; /* pointer to cached file contents */
75 struct stat st; /* copy of stat(2) data for file */
76 int fd; /* fd open on file (short term storage only) */
77 unsigned short include_count; /* number of times file has been read */
78 unsigned short refcnt; /* number of stacked buffers using this file */
79 unsigned char mapped; /* file buffer is mmapped */
80 unsigned char defined; /* cmacro prevents inclusion in this state */
83 /* The cmacro works like this: If it's NULL, the file is to be
84 included again. If it's NEVER_REREAD, the file is never to be
85 included again. Otherwise it is a macro hashnode, and the file is
86 to be included again if the macro is defined or not as specified by
88 #define NEVER_REREAD ((const cpp_hashnode *)-1)
89 #define DO_NOT_REREAD(inc) \
90 ((inc)->cmacro && ((inc)->cmacro == NEVER_REREAD \
91 || ((inc)->cmacro->type == NT_MACRO) == (inc)->defined))
93 static struct file_name_map *read_name_map
94 PARAMS ((cpp_reader *, const char *));
95 static char *read_filename_string PARAMS ((int, FILE *));
96 static char *remap_filename PARAMS ((cpp_reader *, char *,
97 struct file_name_list *));
98 static struct file_name_list *actual_directory
99 PARAMS ((cpp_reader *, const char *));
100 static struct include_file *find_include_file
101 PARAMS ((cpp_reader *, const char *,
102 struct file_name_list *));
103 static struct include_file *open_file PARAMS ((cpp_reader *, const char *));
104 static void read_include_file PARAMS ((cpp_reader *, struct include_file *));
105 static void stack_include_file PARAMS ((cpp_reader *, struct include_file *));
106 static void purge_cache PARAMS ((struct include_file *));
107 static void destroy_include_file_node PARAMS ((splay_tree_value));
108 static int report_missing_guard PARAMS ((splay_tree_node, void *));
110 /* We use a splay tree to store information about all the include
111 files seen in this compilation. The key of each tree node is the
112 physical path to the file. The value is 0 if the file does not
113 exist, or a struct include_file pointer. */
116 destroy_include_file_node (v)
119 struct include_file *f = (struct include_file *)v;
124 free (f); /* The tree is registered with free to free f->name. */
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,
135 destroy_include_file_node);
139 _cpp_cleanup_includes (pfile)
142 splay_tree_delete (pfile->all_include_files);
145 /* Mark a file to not be reread (e.g. #import, read failure). */
147 _cpp_never_reread (file)
148 struct include_file *file;
150 file->cmacro = NEVER_REREAD;
153 /* Put a file name in the splay tree, for the sake of cpp_included ().
154 Assume that FNAME has already had its path simplified. */
156 _cpp_fake_include (pfile, fname)
162 nd = splay_tree_lookup (pfile->all_include_files, (splay_tree_key) fname);
165 struct include_file *file = xcnew (struct include_file);
166 file->name = xstrdup (fname);
167 splay_tree_insert (pfile->all_include_files,
168 (splay_tree_key) file->name,
169 (splay_tree_value) file);
173 /* Given a file name, look it up in the cache; if there is no entry,
174 create one with a non-NULL value (regardless of success in opening
175 the file). If the file doesn't exist or is inaccessible, this
176 entry is flagged so we don't attempt to open it again in the
177 future. If the file isn't open, open it.
179 Returns an include_file structure with an open file descriptor on
180 success, or NULL on failure. */
182 static struct include_file *
183 open_file (pfile, filename)
185 const char *filename;
188 struct include_file *file;
190 nd = splay_tree_lookup (pfile->all_include_files, (splay_tree_key) filename);
194 file = (struct include_file *) nd->value;
196 /* Don't retry opening if we failed previously. */
200 /* Don't reopen an idempotent file. */
201 if (DO_NOT_REREAD (file))
204 /* Don't reopen one which is already loaded. */
205 if (file->buffer != NULL)
210 /* In particular, this clears foundhere. */
211 file = xcnew (struct include_file);
212 file->name = xstrdup (filename);
213 splay_tree_insert (pfile->all_include_files,
214 (splay_tree_key) file->name,
215 (splay_tree_value) file);
218 /* We used to open files in nonblocking mode, but that caused more
219 problems than it solved. Do take care not to acquire a
220 controlling terminal by mistake (this can't happen on sane
221 systems, but paranoia is a virtue).
223 Use the three-argument form of open even though we aren't
224 specifying O_CREAT, to defend against broken system headers.
226 O_BINARY tells some runtime libraries (notably DJGPP) not to do
227 newline translation; we can handle DOS line breaks just fine
230 Special case: the empty string is translated to stdin. */
232 if (filename[0] == '\0')
235 file->fd = open (filename, O_RDONLY | O_NOCTTY | O_BINARY, 0666);
237 if (file->fd != -1 && fstat (file->fd, &file->st) == 0)
239 /* Mark a regular, zero-length file never-reread now. */
240 if (S_ISREG (file->st.st_mode) && file->st.st_size == 0)
242 _cpp_never_reread (file);
250 /* Don't issue an error message if the file doesn't exist. */
251 if (errno != ENOENT && errno != ENOTDIR)
252 cpp_error_from_errno (pfile, filename);
254 /* Create a negative node for this path, and return null. */
260 /* Place the file referenced by INC into a new buffer on PFILE's
261 stack. If there are errors, or the file should not be re-included,
262 a null buffer is pushed. */
265 stack_include_file (pfile, inc)
267 struct include_file *inc;
274 read_include_file (pfile, inc);
276 if (! DO_NOT_REREAD (inc))
277 len = inc->st.st_size;
280 fp = cpp_push_buffer (pfile, inc->buffer, len, BUF_FILE, inc->name);
284 fp->sysp = inc->foundhere->sysp;
286 /* The ->actual_dir field is only used when ignore_srcdir is not in effect;
288 if (!CPP_OPTION (pfile, ignore_srcdir))
289 fp->actual_dir = actual_directory (pfile, inc->name);
291 /* Initialise controlling macro state. */
292 pfile->mi_state = MI_OUTSIDE;
293 pfile->mi_cmacro = 0;
294 pfile->include_depth++;
296 /* Generate the call back. */
298 _cpp_do_file_change (pfile, FC_ENTER, 0, 0);
302 /* Read the file referenced by INC into the file cache.
304 If fd points to a plain file, we might be able to mmap it; we can
305 definitely allocate the buffer all at once. If fd is a pipe or
306 terminal, we can't do either. If fd is something weird, like a
307 block device or a directory, we don't want to read it at all.
309 Unfortunately, different systems use different st.st_mode values
310 for pipes: some have S_ISFIFO, some S_ISSOCK, some are buggy and
311 zero the entire struct stat except a couple fields. Hence we don't
312 even try to figure out what something is, except for plain files,
313 directories, and block devices.
315 FIXME: Flush file cache and try again if we run out of memory. */
318 read_include_file (pfile, inc)
320 struct include_file *inc;
322 ssize_t size, offset, count;
325 static int pagesize = -1;
328 if (DO_NOT_REREAD (inc))
331 if (S_ISREG (inc->st.st_mode))
333 /* off_t might have a wider range than ssize_t - in other words,
334 the max size of a file might be bigger than the address
335 space. We can't handle a file that large. (Anyone with
336 a single source file bigger than 2GB needs to rethink
337 their coding style.) Some systems (e.g. AIX 4.1) define
338 SSIZE_MAX to be much smaller than the actual range of the
339 type. Use INTTYPE_MAXIMUM unconditionally to ensure this
341 if (inc->st.st_size > INTTYPE_MAXIMUM (ssize_t))
343 cpp_error (pfile, "%s is too large", inc->name);
346 size = inc->st.st_size;
351 pagesize = getpagesize ();
353 if (size / pagesize >= MMAP_THRESHOLD)
355 buf = (U_CHAR *) mmap (0, size, PROT_READ, MAP_PRIVATE, inc->fd, 0);
356 if (buf == (U_CHAR *)-1)
363 buf = (U_CHAR *) xmalloc (size);
365 while (offset < size)
367 count = read (inc->fd, buf + offset, size - offset);
372 cpp_warning (pfile, "%s is shorter than expected", inc->name);
379 else if (S_ISBLK (inc->st.st_mode))
381 cpp_error (pfile, "%s is a block device", inc->name);
384 else if (S_ISDIR (inc->st.st_mode))
386 cpp_error (pfile, "%s is a directory", inc->name);
391 /* 8 kilobytes is a sensible starting size. It ought to be
392 bigger than the kernel pipe buffer, and it's definitely
393 bigger than the majority of C source files. */
396 buf = (U_CHAR *) xmalloc (size);
398 while ((count = read (inc->fd, buf + offset, size - offset)) > 0)
402 buf = xrealloc (buf, (size *= 2));
408 buf = xrealloc (buf, offset);
409 inc->st.st_size = offset;
418 cpp_error_from_errno (pfile, inc->name);
420 /* Do not try to read this file again. */
423 _cpp_never_reread (inc);
429 struct include_file *inc;
435 munmap ((PTR) inc->buffer, inc->st.st_size);
438 free ((PTR) inc->buffer);
443 /* Return 1 if the file named by FNAME has been included before in
444 any context, 0 otherwise. */
446 cpp_included (pfile, fname)
450 struct file_name_list *path;
454 if (IS_ABSOLUTE_PATHNAME (fname))
456 /* Just look it up. */
457 nd = splay_tree_lookup (pfile->all_include_files, (splay_tree_key) fname);
458 return (nd && nd->value);
461 /* Search directory path for the file. */
462 name = (char *) alloca (strlen (fname) + pfile->max_include_len
463 + 2 + INCLUDE_LEN_FUDGE);
464 for (path = CPP_OPTION (pfile, quote_include); path; path = path->next)
466 memcpy (name, path->name, path->nlen);
467 name[path->nlen] = '/';
468 strcpy (&name[path->nlen+1], fname);
469 _cpp_simplify_pathname (name);
470 if (CPP_OPTION (pfile, remap))
471 name = remap_filename (pfile, name, path);
473 nd = splay_tree_lookup (pfile->all_include_files, (splay_tree_key) name);
480 /* Search for include file FNAME in the include chain starting at
481 SEARCH_START. Return 0 if there is no such file (or it's un-openable),
482 otherwise an include_file structure. */
484 static struct include_file *
485 find_include_file (pfile, fname, search_start)
488 struct file_name_list *search_start;
490 struct file_name_list *path;
492 struct include_file *file;
494 if (IS_ABSOLUTE_PATHNAME (fname))
495 return open_file (pfile, fname);
497 /* Search directory path for the file. */
498 name = (char *) alloca (strlen (fname) + pfile->max_include_len
499 + 2 + INCLUDE_LEN_FUDGE);
500 for (path = search_start; path; path = path->next)
502 memcpy (name, path->name, path->nlen);
503 name[path->nlen] = '/';
504 strcpy (&name[path->nlen+1], fname);
505 _cpp_simplify_pathname (name);
506 if (CPP_OPTION (pfile, remap))
507 name = remap_filename (pfile, name, path);
509 file = open_file (pfile, name);
512 file->foundhere = path;
519 /* Not everyone who wants to set system-header-ness on a buffer can
520 see the details of a buffer. This is an exported interface because
521 fix-header needs it. */
523 cpp_make_system_header (pfile, syshdr, externc)
529 /* 1 = system header, 2 = system header to be treated as C. */
531 flags = 1 + (externc != 0);
532 pfile->buffer->sysp = flags;
533 _cpp_do_file_change (pfile, FC_RENAME, pfile->buffer->nominal_fname,
534 pfile->buffer->lineno);
537 /* Report on all files that might benefit from a multiple include guard.
540 _cpp_report_missing_guards (pfile)
544 splay_tree_foreach (pfile->all_include_files, report_missing_guard,
549 report_missing_guard (n, b)
553 struct include_file *f = (struct include_file *) n->value;
554 int *bannerp = (int *)b;
556 if (f && f->cmacro == 0 && f->include_count == 1)
560 fputs (_("Multiple include guards may be useful for:\n"), stderr);
563 fputs (f->name, stderr);
569 #define PRINT_THIS_DEP(p, b) (CPP_PRINT_DEPS(p) > (b||p->system_include_depth))
571 _cpp_execute_include (pfile, header, no_reinclude, include_next)
573 const cpp_token *header;
577 struct file_name_list *search_start = 0;
578 unsigned int len = header->val.str.len;
579 unsigned int angle_brackets = header->type == CPP_HEADER_NAME;
580 struct include_file *inc;
583 /* Help protect #include or similar from recursion. */
584 if (pfile->buffer_stack_depth >= CPP_STACK_MAX)
586 cpp_fatal (pfile, "#include nested too deeply");
590 /* Check we've tidied up #include before entering the buffer. */
591 if (pfile->context->prev)
593 cpp_ice (pfile, "attempt to push file buffer with contexts stacked");
597 /* For #include_next, skip in the search path past the dir in which
598 the current file was found. If this is the last directory in the
599 search path, don't include anything. If the current file was
600 specified with an absolute path, use the normal search logic. If
601 this is the primary source file, use the normal search logic and
602 generate a warning. */
605 if (! pfile->buffer->prev)
606 cpp_warning (pfile, "#include_next in primary source file");
609 if (pfile->buffer->inc->foundhere)
611 search_start = pfile->buffer->inc->foundhere->next;
618 fname = alloca (len + 1);
619 memcpy (fname, header->val.str.text, len);
625 search_start = CPP_OPTION (pfile, bracket_include);
626 else if (CPP_OPTION (pfile, ignore_srcdir))
627 search_start = CPP_OPTION (pfile, quote_include);
629 search_start = CPP_BUFFER (pfile)->actual_dir;
633 cpp_error (pfile, "No include path in which to find %s", fname);
638 inc = find_include_file (pfile, fname, search_start);
642 /* For -M, add the file to the dependencies on its first inclusion. */
643 if (!inc->include_count && PRINT_THIS_DEP (pfile, angle_brackets))
644 deps_add_dep (pfile->deps, inc->name);
645 inc->include_count++;
647 /* Actually process the file. */
648 stack_include_file (pfile, inc);
651 pfile->system_include_depth++;
653 if (! DO_NOT_REREAD (inc))
656 _cpp_never_reread (inc);
658 /* Handle -H option. */
659 if (CPP_OPTION (pfile, print_include_names))
661 cpp_buffer *fp = CPP_BUFFER (pfile);
662 while ((fp = CPP_PREV_BUFFER (fp)) != NULL)
664 fprintf (stderr, " %s\n", inc->name);
671 if (CPP_OPTION (pfile, print_deps_missing_files)
672 && PRINT_THIS_DEP (pfile, angle_brackets))
674 if (!angle_brackets || IS_ABSOLUTE_PATHNAME (fname))
675 deps_add_dep (pfile->deps, fname);
679 struct file_name_list *ptr;
682 /* If requested as a system header, assume it belongs in
683 the first system header directory. */
684 if (CPP_OPTION (pfile, bracket_include))
685 ptr = CPP_OPTION (pfile, bracket_include);
687 ptr = CPP_OPTION (pfile, quote_include);
689 len = strlen (ptr->name);
690 p = (char *) alloca (len + strlen (fname) + 2);
693 memcpy (p, ptr->name, len);
696 strcpy (p + len, fname);
697 _cpp_simplify_pathname (p);
698 deps_add_dep (pfile->deps, p);
701 /* If -M was specified, and this header file won't be added to
702 the dependency list, then don't count this as an error,
703 because we can still produce correct output. Otherwise, we
704 can't produce correct output, because there may be
705 dependencies we need inside the missing file, and we don't
706 know what directory this missing file exists in. */
707 else if (CPP_PRINT_DEPS (pfile)
708 && ! PRINT_THIS_DEP (pfile, angle_brackets))
709 cpp_warning (pfile, "No include path in which to find %s", fname);
711 cpp_error_from_errno (pfile, fname);
714 /* Locate file F, and determine whether it is newer than PFILE. Return -1,
715 if F cannot be located or dated, 1, if it is newer and 0 if older. */
717 _cpp_compare_file_date (pfile, f)
721 unsigned int len = f->val.str.len;
723 struct file_name_list *search_start;
724 struct include_file *inc;
726 if (f->type == CPP_HEADER_NAME)
727 search_start = CPP_OPTION (pfile, bracket_include);
728 else if (CPP_OPTION (pfile, ignore_srcdir))
729 search_start = CPP_OPTION (pfile, quote_include);
731 search_start = CPP_BUFFER (pfile)->actual_dir;
733 fname = alloca (len + 1);
734 memcpy (fname, f->val.str.text, len);
736 inc = find_include_file (pfile, fname, search_start);
746 return inc->st.st_mtime > CPP_BUFFER (pfile)->inc->st.st_mtime;
750 /* Push an input buffer and load it up with the contents of FNAME.
751 If FNAME is "" or NULL, read standard input. */
753 _cpp_read_file (pfile, fname)
757 struct include_file *f;
762 f = open_file (pfile, fname);
766 cpp_error_from_errno (pfile, fname);
770 if (CPP_OPTION (pfile, print_deps))
771 deps_add_dep (pfile->deps, f->name);
773 stack_include_file (pfile, f);
777 /* Do appropriate cleanup when a file buffer is popped off the input
780 _cpp_pop_file_buffer (pfile, buf)
784 struct include_file *inc = buf->inc;
786 if (pfile->system_include_depth)
787 pfile->system_include_depth--;
788 if (pfile->include_depth)
789 pfile->include_depth--;
791 /* Record the inclusion-preventing macro and its definedness. */
792 if (pfile->mi_state == MI_OUTSIDE && inc->cmacro != NEVER_REREAD)
794 /* This could be NULL meaning no controlling macro. */
795 inc->cmacro = pfile->mi_cmacro;
799 /* Invalidate control macros in the #including file. */
800 pfile->mi_state = MI_FAILED;
803 if (inc->refcnt == 0 && DO_NOT_REREAD (inc))
807 /* The file_name_map structure holds a mapping of file names for a
808 particular directory. This mapping is read from the file named
809 FILE_NAME_MAP_FILE in that directory. Such a file can be used to
810 map filenames on a file system with severe filename restrictions,
811 such as DOS. The format of the file name map file is just a series
812 of lines with two tokens on each line. The first token is the name
813 to map, and the second token is the actual name to use. */
817 struct file_name_map *map_next;
822 #define FILE_NAME_MAP_FILE "header.gcc"
824 /* Read a space delimited string of unlimited length from a stdio
828 read_filename_string (ch, f)
836 set = alloc = xmalloc (len + 1);
840 while ((ch = getc (f)) != EOF && ! is_space(ch))
842 if (set - alloc == len)
845 alloc = xrealloc (alloc, len + 1);
846 set = alloc + len / 2;
856 /* This structure holds a linked list of file name maps, one per directory. */
858 struct file_name_map_list
860 struct file_name_map_list *map_list_next;
862 struct file_name_map *map_list_map;
865 /* Read the file name map file for DIRNAME. */
867 static struct file_name_map *
868 read_name_map (pfile, dirname)
872 register struct file_name_map_list *map_list_ptr;
876 /* Check the cache of directories, and mappings in their remap file. */
877 for (map_list_ptr = CPP_OPTION (pfile, map_list); map_list_ptr;
878 map_list_ptr = map_list_ptr->map_list_next)
879 if (! strcmp (map_list_ptr->map_list_name, dirname))
880 return map_list_ptr->map_list_map;
882 map_list_ptr = ((struct file_name_map_list *)
883 xmalloc (sizeof (struct file_name_map_list)));
884 map_list_ptr->map_list_name = xstrdup (dirname);
886 /* The end of the list ends in NULL. */
887 map_list_ptr->map_list_map = NULL;
889 name = (char *) alloca (strlen (dirname) + strlen (FILE_NAME_MAP_FILE) + 2);
890 strcpy (name, dirname);
893 strcat (name, FILE_NAME_MAP_FILE);
894 f = fopen (name, "r");
896 /* Silently return NULL if we cannot open. */
900 int dirlen = strlen (dirname);
902 while ((ch = getc (f)) != EOF)
905 struct file_name_map *ptr;
909 from = read_filename_string (ch, f);
910 while ((ch = getc (f)) != EOF && is_hspace(ch))
912 to = read_filename_string (ch, f);
914 ptr = ((struct file_name_map *)
915 xmalloc (sizeof (struct file_name_map)));
916 ptr->map_from = from;
918 /* Make the real filename absolute. */
919 if (IS_ABSOLUTE_PATHNAME (to))
923 ptr->map_to = xmalloc (dirlen + strlen (to) + 2);
924 strcpy (ptr->map_to, dirname);
925 ptr->map_to[dirlen] = '/';
926 strcpy (ptr->map_to + dirlen + 1, to);
930 ptr->map_next = map_list_ptr->map_list_map;
931 map_list_ptr->map_list_map = ptr;
933 while ((ch = getc (f)) != '\n')
940 /* Add this information to the cache. */
941 map_list_ptr->map_list_next = CPP_OPTION (pfile, map_list);
942 CPP_OPTION (pfile, map_list) = map_list_ptr;
944 return map_list_ptr->map_list_map;
947 /* Remap NAME based on the file_name_map (if any) for LOC. */
950 remap_filename (pfile, name, loc)
953 struct file_name_list *loc;
955 struct file_name_map *map;
956 const char *from, *p;
961 loc->name_map = read_name_map (pfile, loc->name ? loc->name : ".");
966 from = name + strlen (loc->name) + 1;
968 for (map = loc->name_map; map; map = map->map_next)
969 if (!strcmp (map->map_from, from))
972 /* Try to find a mapping file for the particular directory we are
973 looking in. Thus #include <sys/types.h> will look up sys/types.h
974 in /usr/include/header.gcc and look up types.h in
975 /usr/include/sys/header.gcc. */
976 p = strrchr (name, '/');
980 /* We know p != name as absolute paths don't call remap_filename. */
982 cpp_ice (pfile, "absolute file name in remap_filename");
984 dir = (char *) alloca (p - name + 1);
985 memcpy (dir, name, p - name);
986 dir[p - name] = '\0';
989 for (map = read_name_map (pfile, dir); map; map = map->map_next)
990 if (! strcmp (map->map_from, from))
996 /* Given a path FNAME, extract the directory component and place it
997 onto the actual_dirs list. Return a pointer to the allocated
998 file_name_list structure. These structures are used to implement
999 current-directory "" include searching. */
1001 static struct file_name_list *
1002 actual_directory (pfile, fname)
1006 char *last_slash, *dir;
1008 struct file_name_list *x;
1010 dir = xstrdup (fname);
1011 last_slash = strrchr (dir, '/');
1014 if (last_slash == dir)
1017 last_slash[1] = '\0';
1021 dlen = last_slash - dir;
1028 dir = xstrdup (".");
1032 if (dlen > pfile->max_include_len)
1033 pfile->max_include_len = dlen;
1035 for (x = pfile->actual_dirs; x; x = x->alloc)
1036 if (!strcmp (x->name, dir))
1042 /* Not found, make a new one. */
1043 x = (struct file_name_list *) xmalloc (sizeof (struct file_name_list));
1046 x->next = CPP_OPTION (pfile, quote_include);
1047 x->alloc = pfile->actual_dirs;
1048 x->sysp = pfile->buffer->sysp;
1051 pfile->actual_dirs = x;
1055 /* Simplify a path name in place, deleting redundant components. This
1056 reduces OS overhead and guarantees that equivalent paths compare
1057 the same (modulo symlinks).
1060 foo/bar/../quux foo/quux
1064 //quux //quux (POSIX allows leading // as a namespace escape)
1066 Guarantees no trailing slashes. All transforms reduce the length
1070 _cpp_simplify_pathname (path)
1077 #if defined (HAVE_DOS_BASED_FILE_SYSTEM)
1078 /* Convert all backslashes to slashes. */
1079 for (from = path; *from; from++)
1080 if (*from == '\\') *from = '/';
1082 /* Skip over leading drive letter if present. */
1083 if (ISALPHA (path[0]) && path[1] == ':')
1084 from = to = &path[2];
1091 /* Remove redundant initial /s. */
1100 /* 3 or more initial /s are equivalent to 1 /. */
1101 while (*++from == '/');
1103 /* On some hosts // differs from /; Posix allows this. */
1111 while (*from == '/')
1114 if (from[0] == '.' && from[1] == '/')
1116 else if (from[0] == '.' && from[1] == '\0')
1118 else if (from[0] == '.' && from[1] == '.' && from[2] == '/')
1135 while (to > base && *to != '/') to--;
1141 else if (from[0] == '.' && from[1] == '.' && from[2] == '\0')
1154 while (to > base && *to != '/') to--;
1161 /* Copy this component and trailing /, if any. */
1162 while ((*to++ = *from++) != '/')
1174 /* Trim trailing slash */
1175 if (to[0] == '/' && (!absolute || to > path+1))
1178 /* Change the empty string to "." so that stat() on the result
1179 will always work. */