2006-07-25 Paolo Bonzini <bonzini@gnu.org>

[pf3gnuchains/gcc-fork.git] / gcc / function.c

diff --git a/gcc/function.c b/gcc/function.c
index 4f989dd..e912d6a 100644 (file)
--- a/gcc/function.c
+++ b/gcc/function.c
@@ -1,6 +1,6 @@
 /* Expands front end tree to back end RTL for GCC.
    Copyright (C) 1987, 1988, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
-   1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005
+   1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006
    Free Software Foundation, Inc.
 
 This file is part of GCC.
@@ -1749,15 +1749,21 @@ aggregate_value_p (tree exp, tree fntype)
 
   tree type = (TYPE_P (exp)) ? exp : TREE_TYPE (exp);
 
+  /* DECL node associated with FNTYPE when relevant, which we might need to
+     check for by-invisible-reference returns, typically for CALL_EXPR input
+     EXPressions.  */
+  tree fndecl = NULL_TREE;
+  
   if (fntype)
     switch (TREE_CODE (fntype))
       {
       case CALL_EXPR:
-       fntype = get_callee_fndecl (fntype);
-       fntype = fntype ? TREE_TYPE (fntype) : 0;
+       fndecl = get_callee_fndecl (fntype);
+       fntype = fndecl ? TREE_TYPE (fndecl) : 0;
        break;
       case FUNCTION_DECL:
-       fntype = TREE_TYPE (fntype);
+       fndecl = fntype;
+       fntype = TREE_TYPE (fndecl);
        break;
       case FUNCTION_TYPE:
       case METHOD_TYPE:
@@ -1772,11 +1778,23 @@ aggregate_value_p (tree exp, tree fntype)
 
   if (TREE_CODE (type) == VOID_TYPE)
     return 0;
+
   /* If the front end has decided that this needs to be passed by
      reference, do so.  */
   if ((TREE_CODE (exp) == PARM_DECL || TREE_CODE (exp) == RESULT_DECL)
       && DECL_BY_REFERENCE (exp))
     return 1;
+
+  /* If the EXPression is a CALL_EXPR, honor DECL_BY_REFERENCE set on the
+     called function RESULT_DECL, meaning the function returns in memory by
+     invisible reference.  This check lets front-ends not set TREE_ADDRESSABLE
+     on the function type, which used to be the way to request such a return
+     mechanism but might now be causing troubles at gimplification time if
+     temporaries with the function type need to be created.  */
+  if (TREE_CODE (exp) == CALL_EXPR && fndecl && DECL_RESULT (fndecl)
+      && DECL_BY_REFERENCE (DECL_RESULT (fndecl)))
+    return 1;
+      
   if (targetm.calls.return_in_memory (type, fntype))
     return 1;
   /* Types that are TREE_ADDRESSABLE must be constructed in memory,
@@ -5535,7 +5553,8 @@ record_block_change (tree block)
 }
 
 /* Finishes record of boundaries.  */
-void finalize_block_changes (void)
+void
+finalize_block_changes (void)
 {
   record_block_change (DECL_INITIAL (current_function_decl));
 }