c-typeck.c (initializer_constant_valid_p): Allow conversion of 0 of any size to a pointer.

	* c-typeck.c (initializer_constant_valid_p): Allow conversion of 0
	of any size to a pointer.

From-SVN: r21697

gcc/ChangeLog

+Thu Aug 13 15:24:48 1998  Jason Merrill  <jason@yorick.cygnus.com>
+
+	* c-typeck.c (initializer_constant_valid_p): Allow conversion of 0
+	of any size to a pointer.
+
 Thu Aug 13 12:53:13 1998  Jim Wilson  <wilson@cygnus.com>
 
 	* i386/winnt.c (i386_pe_asm_file_end): Check TREE_SYMBOL_REFERENCED.
@@ -567,7 +572,7 @@ Tue Jul 28 22:31:12 1998  Craig Burley  <burley@gnu.org>
 	SUBREG, MEM.
 	* rtlanal.c (replace_rtx): Prohibit replaces in	CONST_DOUBLE. 
 
-Tue Jul 28 11:33:09 1998  Mark Mitchell  <mark@markmitchell.com>
+
 
 	* cplus-dem.c (type_kind_t): New type.
 	(demangle_template_value_parm): Add type_kind_t parameter.  Rely

gcc/c-typeck.c

@@ -4423,13 +4423,18 @@ initializer_constant_valid_p (value, endtype)
 	return initializer_constant_valid_p (TREE_OPERAND (value, 0),
 					     endtype);
 
-      /* Likewise conversions from int to pointers.  */
+      /* Likewise conversions from int to pointers, but also allow
+	 conversions from 0.  */
       if (TREE_CODE (TREE_TYPE (value)) == POINTER_TYPE
-	  && TREE_CODE (TREE_TYPE (TREE_OPERAND (value, 0))) == INTEGER_TYPE
-	  && (TYPE_PRECISION (TREE_TYPE (value))
-	      <= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (value, 0)))))
+	  && TREE_CODE (TREE_TYPE (TREE_OPERAND (value, 0))) == INTEGER_TYPE)
+	{
+	  if (integer_zerop (TREE_OPERAND (value, 0)))
+	    return null_pointer_node;
+	  else if (TYPE_PRECISION (TREE_TYPE (value))
+		   <= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (value, 0))))
 	    return initializer_constant_valid_p (TREE_OPERAND (value, 0),
 						 endtype);
+	}
 
       /* Allow conversions to union types if the value inside is okay.  */
       if (TREE_CODE (TREE_TYPE (value)) == UNION_TYPE)