re PR c++/29226 (ICE in make_decl_rtl, at varasm.c:886)

	PR c++/29226
	* typeck.c (cxx_sizeof_or_alignof_type): Tidy.  In templates, do
	not try to actually evaluate sizeof for a VLA type.
	PR c++/29226
	* g++.dg/template/vla1.C: New test.

From-SVN: r117375

2 files changed, 27 insertions, 20 deletions

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index d21bf43..3c2ff36 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2006-10-02  Mark Mitchell  <mark@codesourcery.com>
+
+	PR c++/29226
+	* typeck.c (cxx_sizeof_or_alignof_type): Tidy.  In templates, do
+	not try to actually evaluate sizeof for a VLA type.
+
 2006-10-01  Mark Mitchell  <mark@codesourcery.com>
 
 	PR c++/29105
diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index 4713f05..9f8d5e4 100644
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -1241,38 +1241,39 @@ compparms (tree parms1, tree parms2)
 tree
 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
 {
-  enum tree_code type_code;
   tree value;
-  const char *op_name;
 
   gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
   if (type == error_mark_node)
     return error_mark_node;
 
-  if (dependent_type_p (type))
-    {
-      value = build_min (op, size_type_node, type);
-      TREE_READONLY (value) = 1;
-      return value;
-    }
-
-  op_name = operator_name_info[(int) op].name;
-
   type = non_reference (type);
-  type_code = TREE_CODE (type);
-
-  if (type_code == METHOD_TYPE)
+  if (TREE_CODE (type) == METHOD_TYPE)
     {
       if (complain && (pedantic || warn_pointer_arith))
-	pedwarn ("invalid application of %qs to a member function", op_name);
+	pedwarn ("invalid application of %qs to a member function", 
+		 operator_name_info[(int) op].name);
       value = size_one_node;
     }
-  else
-    value = c_sizeof_or_alignof_type (complete_type (type),
-				      op == SIZEOF_EXPR,
-				      complain);
 
-  return value;
+  if (dependent_type_p (type)
+      /* VLA types will have a non-constant size.  In the body of an
+	 uninstantiated template, we don't need to try to compute the
+	 value, because the sizeof expression is not an integral
+	 constant expression in that case.  And, if we do try to
+	 compute the value, we'll likely end up with SAVE_EXPRs, which
+	 the template substitution machinery does not expect to see.  */
+      || (processing_template_decl && 
+	  TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST))
+    {
+      value = build_min (op, size_type_node, type);
+      TREE_READONLY (value) = 1;
+      return value;
+    }
+
+  return c_sizeof_or_alignof_type (complete_type (type),
+				   op == SIZEOF_EXPR,
+				   complain);
 }
 
 /* Process a sizeof expression where the operand is an expression.  */