Formerly vpath.c.~9~

diff --git a/vpath.c b/vpath.c
index 730f989..e58cf07 100644 (file)
--- a/vpath.c
+++ b/vpath.c
@@ -246,13 +246,15 @@ construct_vpath_list (pattern, dirpath)
 }
 \f
 /* Search the VPATH list whose pattern matches *FILE for a directory
-   where the name pointed to by FILE exists.  If it is found, the pointer
-   in FILE is set to the newly malloc'd name of the existing file and
-   we return 1.  Otherwise we return 0.  */
+   where the name pointed to by FILE exists.  If it is found, we set *FILE to
+   the newly malloc'd name of the existing file, *MTIME_PTR (if MTIME_PTR is
+   not NULL) to its modtime (or zero if no stat call was done), and return 1.
+   Otherwise we return 0.  */
 
 int
-vpath_search (file)
+vpath_search (file, mtime_ptr)
      char **file;
+     time_t *mtime_ptr;
 {
   register struct vpath *v;
 
@@ -264,11 +266,11 @@ vpath_search (file)
 
   for (v = vpaths; v != 0; v = v->next)
     if (pattern_matches (v->pattern, v->percent, *file))
-      if (selective_vpath_search (v, file))
+      if (selective_vpath_search (v, file, mtime_ptr))
        return 1;
 
   if (general_vpath != 0
-      && selective_vpath_search (general_vpath, file))
+      && selective_vpath_search (general_vpath, file, mtime_ptr))
     return 1;
 
   return 0;
@@ -276,14 +278,16 @@ vpath_search (file)
 
 
 /* Search the given VPATH list for a directory where the name pointed
-   to by FILE exists.  If it is found, the pointer in FILE
-   is set to the newly malloc'd name of the existing file and we return 1.
+   to by FILE exists.  If it is found, we set *FILE to the newly malloc'd
+   name of the existing file, *MTIME_PTR (if MTIME_PTR is not NULL) to
+   its modtime (or zero if no stat call was done), and we return 1.
    Otherwise we return 0.  */
 
 static int
-selective_vpath_search (path, file)
+selective_vpath_search (path, file, mtime_ptr)
      struct vpath *path;
      char **file;
+     time_t *mtime_ptr;
 {
   int not_target;
   char *name, *n;
@@ -323,6 +327,8 @@ selective_vpath_search (path, file)
   /* Try each VPATH entry.  */
   for (i = 0; vpath[i] != 0; ++i)
     {
+      int exists_in_cache = 0;
+
       n = name;
 
       /* Put the next VPATH entry into NAME at N and increment N past it.  */
@@ -360,20 +366,38 @@ selective_vpath_search (path, file)
          /* We know the directory is in the hash table now because either
             construct_vpath_list or the code just above put it there.
             Does the file we seek exist in it?  */
-         exists = dir_file_exists_p (name, filename);
+         exists_in_cache = exists = dir_file_exists_p (name, filename);
        }
 
       if (exists)
        {
-         /* We have found a file.
-            Store the name we found into *FILE for the caller.  */
+         /* The file is in the directory cache.
+            Now check that it actually exists in the filesystem.
+            The cache may be out of date.  When vpath thinks a file
+            exists, but stat fails for it, confusion results in the
+            higher levels.  */
+
+         struct stat st;
 
          /* Put the slash back in NAME.  */
          *n = '/';
 
-         *file = savestring (name, (n + 1 - name) + flen);
+         if (!exists_in_cache  /* Makefile-mentioned file need not exist.  */
+             || stat (name, &st) == 0) /* Does it really exist?  */
+           {
+             /* We have found a file.
+                Store the name we found into *FILE for the caller.  */
 
-         return 1;
+             *file = savestring (name, (n + 1 - name) + flen);
+
+             if (mtime_ptr != 0)
+               /* Store the modtime into *MTIME_PTR for the caller.
+                  If we have had no need to stat the file here,
+                  we record a zero modtime to indicate this.  */
+               *mtime_ptr = exists_in_cache ? st.st_mtime : (time_t) 0;
+
+             return 1;
+           }
        }
     }