re PR c++/23171 (ICE on pointer initialization with C99 initializer)

	PR c++/23171
	* varasm.c (initializer_constant_valid_p): An ADDR_EXPR of a
	CONSTRUCTOR is invalid.

	PR c++/23171
	* g++.dg/opt/init1.C: New test.

From-SVN: r109035

gcc/ChangeLog

+2005-12-24  Mark Mitchell  <mark@codesourcery.com>
+
+	PR c++/23171
+	* varasm.c (initializer_constant_valid_p): An ADDR_EXPR of a
+	CONSTRUCTOR is invalid.
+
 2005-12-23  Daniel Berlin  <dberlin@dberlin.org>
 
 	* tree-pass.h (pass_eliminate_useless_stores): Remove.

gcc/testsuite/ChangeLog

+2005-12-24  Mark Mitchell  <mark@codesourcery.com>
+
+	PR c++/23171
+	* g++.dg/opt/init1.C: New test.
+
 2005-12-23  Mark Mitchell  <mark@codesourcery.com>
 
 	PR c++/24671

gcc/testsuite/g++.dg/opt/init1.C

+// PR c++/23171
+// { dg-options "-O" }
+
+int *p = (int*)(int[1]){0};

gcc/varasm.c

@@ -3477,18 +3477,24 @@ initializer_constant_valid_p (tree value, tree endtype)
     case ADDR_EXPR:
     case FDESC_EXPR:
       value = staticp (TREE_OPERAND (value, 0));
-      /* "&(*a).f" is like unto pointer arithmetic.  If "a" turns out to
-	 be a constant, this is old-skool offsetof-like nonsense.  */
-      if (value
-	  && TREE_CODE (value) == INDIRECT_REF
-	  && TREE_CONSTANT (TREE_OPERAND (value, 0)))
-	return null_pointer_node;
-      /* Taking the address of a nested function involves a trampoline.  */
-      if (value
-	  && TREE_CODE (value) == FUNCTION_DECL
-	  && ((decl_function_context (value) && !DECL_NO_STATIC_CHAIN (value))
-	      || DECL_DLLIMPORT_P (value)))
-	return NULL_TREE;
+      if (value)
+	{
+	  /* "&(*a).f" is like unto pointer arithmetic.  If "a" turns out to
+	     be a constant, this is old-skool offsetof-like nonsense.  */
+	  if (TREE_CODE (value) == INDIRECT_REF
+	      && TREE_CONSTANT (TREE_OPERAND (value, 0)))
+	    return null_pointer_node;
+	  /* Taking the address of a nested function involves a trampoline.  */
+	  if (TREE_CODE (value) == FUNCTION_DECL
+	      && ((decl_function_context (value) 
+		   && !DECL_NO_STATIC_CHAIN (value))
+		  || DECL_DLLIMPORT_P (value)))
+	    return NULL_TREE;
+	  /* "&{...}" requires a temporary to hold the constructed
+	     object.  */
+	  if (TREE_CODE (value) == CONSTRUCTOR)
+	    return NULL_TREE;
+	}
       return value;
 
     case VIEW_CONVERT_EXPR: