Re: appending target-specific variables: make 3.79 bug or feature?

[Paul D. Smith]

%% "William F. Dowling" <address@hidden> writes:

  wfd> I have come across a difference between gnu make 3.78 and 3.79 that
  wfd> may be a bug, and is certainly an incompatibility.  Consider this
  wfd> Makefile:

  wfd> foo : a += b
  wfd> foo : a += c
  wfd> foo :
  wfd>  @echo $(a)

  wfd> In 3.78 and earlier, the output of make is 'b c'; in 3.79 it is 'c'.

Did I reply to this already?  I can't recall.

Anyway, this is a known bug, and it's been fixed in the development
sources.  Unfortunately, there was some work done on the FSF's servers
and the web-based bug database browser hasn't come back up yet, so you
can't go find the patch there.

I'll include it below; it might not apply cleanly but you should be able
to apply it by hand if not (it's not very big).

--- make-3.79.1/variable.c      Fri May 19 12:36:08 2000
+++ make/variable.c     Mon Aug 21 02:18:36 2000
@@ -201,9 +201,6 @@
          sptr = value;
          scnt = 0;
 
-          if (listp)
-            *listp = current_variable_set_list;
-
          while ((sptr = strchr (sptr, '$')))
            {
              scnt++;
@@ -903,19 +900,23 @@
       value = p;
       break;
     case f_append:
-      /* If we have += but we're in a target variable context, defer the
-         append until the context expansion.  */
+      {
+        struct variable_set_list *saved_next = current_variable_set_list->next;
+
+        /* If we have += but we're in a target variable context, we want to
+           append only with other variables in the context of this target.  */
       if (target_var)
         {
           append = 1;
-          flavor = f_recursive;
-          value = p;
-          break;
+            current_variable_set_list->next = 0;
         }
 
       /* An appending variable definition "var += value".
         Extract the old value and append the new one.  */
       v = lookup_variable (expanded_name, strlen (expanded_name));
+
+        current_variable_set_list->next = saved_next;
+
       if (v == 0)
        {
          /* There was no old value.
@@ -931,7 +932,7 @@
 
          if (v->recursive)
            /* The previous definition of the variable was recursive.
-              The new value comes from the unexpanded old and new values.  */
+                 The new value is the unexpanded old and new values. */
            flavor = f_recursive;
          else
            /* The previous definition of the variable was simple.
@@ -949,6 +950,7 @@
          bcopy (p, &value[oldlen + 1], newlen + 1);
        }
     }
+    }
 
 #ifdef __MSDOS__
   /* Many Unix Makefiles include a line saying "SHELL=/bin/sh", but


-- 
-------------------------------------------------------------------------------
 Paul D. Smith <address@hidden>          Find some GNU make tips at:
 http://www.gnu.org                      http://www.paulandlesley.org/gmake/
 "Please remain calm...I may be mad, but I am a professional." --Mad Scientist