re PR c/19031 (#pragma weak handling changes in 4.0.0)

        PR c/19031
        * c-decl.c (pop_file_scope): Call maybe_apply_pending_pragma_weaks.
        * c-lang.c (finish_file): Don't do it here.
        * objc/objc-act.c (objc_finish_file): Likewise.

        * cgraph.c (decl_assembler_name_equal): New.
        (cgraph_node_for_asm, cgraph_varpool_node_for_asm): New.
        (cgraph_varpool_node): Actually link up cgraph_varpool_nodes.
        * cgraph.h (struct cgraph_varpool_node): Add next.
        (cgraph_node_for_asm, cgraph_varpool_node_for_asm): Declare.
        * varasm.c (assemble_alias): Mark the target as needed.

From-SVN: r92803

1 files changed, 39 insertions, 1 deletions

diff --git a/gcc/varasm.c b/gcc/varasm.c
index 362abaf..7c58b98 100644
--- a/gcc/varasm.c
+++ b/gcc/varasm.c
@@ -4344,7 +4344,7 @@ globalize_decl (tree decl)
    the symbol for TARGET.  */
 
 void
-assemble_alias (tree decl, tree target ATTRIBUTE_UNUSED)
+assemble_alias (tree decl, tree target)
 {
   const char *name;
 
@@ -4395,6 +4395,44 @@ assemble_alias (tree decl, tree target ATTRIBUTE_UNUSED)
 #endif
 #endif
 
+  /* Tell cgraph that the aliased symbol is needed.  We *could* be more
+     specific and tell cgraph about the relationship between the two
+     symbols, but given that aliases virtually always exist for a reason,
+     it doesn't seem worthwhile.  */
+  if (flag_unit_at_a_time)
+    {
+      struct cgraph_node *fnode = NULL;
+      struct cgraph_varpool_node *vnode = NULL;
+
+      if (TREE_CODE (decl) == FUNCTION_DECL)
+	{
+	  fnode = cgraph_node_for_asm (target);
+	  if (fnode != NULL)
+	    cgraph_mark_needed_node (fnode);
+	  else
+	    {
+	      vnode = cgraph_varpool_node_for_asm (target);
+	      if (vnode != NULL)
+		cgraph_varpool_mark_needed_node (vnode);
+	    }
+	}
+      else
+	{
+	  vnode = cgraph_varpool_node_for_asm (target);
+	  if (vnode != NULL)
+	    cgraph_varpool_mark_needed_node (vnode);
+	  else
+	    {
+	      fnode = cgraph_node_for_asm (target);
+	      if (fnode != NULL)
+		cgraph_mark_needed_node (fnode);
+	    }
+	}
+
+      if (fnode == NULL && vnode == NULL)
+	warning ("%qD aliased to undefined symbol %qE", decl, target);
+    }
+
   TREE_USED (decl) = 1;
   TREE_ASM_WRITTEN (decl) = 1;
   TREE_ASM_WRITTEN (DECL_ASSEMBLER_NAME (decl)) = 1;