From 659fc6b55e28740c74d66dbe3bda765d1004a12e Mon Sep 17 00:00:00 2001
From: Boris Kolpackov <boris@kolpackov.net>
Date: Sun, 27 Feb 2005 21:40:23 +0000
Subject: Implementation of the second expansion in explicit rules, static
 pattern rules and implicit rules.

---
 file.c | 109 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 97 insertions(+), 12 deletions(-)

(limited to 'file.c')

diff --git a/file.c b/file.c
index ae99745..70e5358 100644
--- a/file.c
+++ b/file.c
@@ -416,12 +416,14 @@ snap_deps (void)
 {
   register struct file *f;
   register struct file *f2;
-  register struct dep *d;
+  register struct dep *d, *d1;
   register struct file **file_slot_0;
   register struct file **file_slot;
   register struct file **file_end;
 
-  /* Enter each dependency name as a file.  */
+  /* Perform second expansion and enter each dependency
+     name as a file. */
+
   /* We must use hash_dump (), because within this loop
      we might add new files to the table, possibly causing
      an in-situ table expansion.  */
@@ -429,16 +431,99 @@ snap_deps (void)
   file_end = file_slot_0 + files.ht_fill;
   for (file_slot = file_slot_0; file_slot < file_end; file_slot++)
     for (f2 = *file_slot; f2 != 0; f2 = f2->prev)
-      for (d = f2->deps; d != 0; d = d->next)
-	if (d->name != 0)
-	  {
-	    d->file = lookup_file (d->name);
-	    if (d->file == 0)
-	      d->file = enter_file (d->name);
-	    else
-	      free (d->name);
-	    d->name = 0;
-	  }
+      {
+        struct dep *new = 0;
+        struct dep *old = f2->deps;
+        unsigned int last_dep_has_cmds = f2->updating;
+
+        f2->updating = 0;
+        f2->deps = 0;
+
+        /* We are going to do second expansion so initialize file
+           variables for the file. */
+        initialize_file_variables (f2, 0);
+
+        for (d = old; d != 0; d = d->next)
+          {
+            if (d->name != 0)
+              {
+                char *p;
+                struct dep **d_ptr;
+
+                set_file_variables (f2);
+
+                p = variable_expand_for_file (d->name, f2);
+
+                /* Parse the dependencies.  */
+                new = (struct dep *)
+                  multi_glob (
+                    parse_file_seq (&p, '|', sizeof (struct dep), 1),
+                    sizeof (struct dep));
+
+                if (*p)
+                  {
+                    /* Files that follow '|' are special prerequisites that
+                       need only exist in order to satisfy the dependency.
+                       Their modification times are irrelevant.  */
+
+                    struct dep *d;
+                    for (d_ptr = &new; *d_ptr; d_ptr = &(*d_ptr)->next)
+                      ;
+                    ++p;
+
+                    *d_ptr = (struct dep *)
+                      multi_glob (
+                        parse_file_seq (&p, '\0', sizeof (struct dep), 1),
+                        sizeof (struct dep));
+
+                    for (d = *d_ptr; d != 0; d = d->next)
+                      d->ignore_mtime = 1;
+                  }
+
+                /* Enter them as files. */
+                for (d1 = new; d1 != 0; d1 = d1->next)
+                  {
+                    d1->file = lookup_file (d1->name);
+                    if (d1->file == 0)
+                      d1->file = enter_file (d1->name);
+                    else
+                      free (d1->name);
+                    d1->name = 0;
+                  }
+
+                /* Add newly parsed deps to f2->deps. If this is the last
+                   dependency line and this target has commands then put
+                   it in front so the last dependency line (the one with
+                   commands) ends up being the first. This is important
+                   because people expect $< to hold first prerequisite
+                   from the rule with commands. If it is not the last
+                   dependency line or the rule does not have commands
+                   then link it at the end so it appears in makefile
+                   order.  */
+
+                if (new != 0)
+                  {
+                    if (d->next == 0 && last_dep_has_cmds)
+                    {
+                      for (d_ptr = &new; *d_ptr; d_ptr = &(*d_ptr)->next)
+                        ;
+
+                      *d_ptr = f2->deps;
+                      f2->deps = new;
+                    }
+                    else
+                    {
+                      for (d_ptr = &(f2->deps); *d_ptr; d_ptr = &(*d_ptr)->next)
+                        ;
+
+                      *d_ptr = new;
+                    }
+                  }
+              }
+          }
+
+        free_dep_chain (old);
+      }
   free (file_slot_0);
 
   for (f = lookup_file (".PRECIOUS"); f != 0; f = f->prev)
-- 
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