re PR c/3170 (bogus "suggest parentheses" warning)

	PR c/3170
	PR c/3422
	* c-typeck.c (default_conversion): Retain the original expression
	codes.
	* gcc.dg/Wparentheses-1.c: New tests.

From-SVN: r46705

gcc/ChangeLog

+2001-11-01  Neil Booth  <neil@daikokuya.demon.co.uk>
+
+	* c-typeck.c (default_conversion): Retain the original expression
+	codes.
+	* gcc.dg/Wparentheses.c: New tests.
+
 2001-11-01  David S. Miller  <davem@redhat.com>
 
 	* doc/install.texi (Specific, sparc-sun-solaris2*): Bring

gcc/c-typeck.c

@@ -847,6 +847,7 @@ tree
 default_conversion (exp)
      tree exp;
 {
+  tree orig_exp;
   tree type = TREE_TYPE (exp);
   enum tree_code code = TREE_CODE (type);
 
@@ -868,11 +869,16 @@ default_conversion (exp)
 
      Do not use STRIP_NOPS here!  It will remove conversions from pointer
      to integer and cause infinite recursion.  */
+  orig_exp = exp;
   while (TREE_CODE (exp) == NON_LVALUE_EXPR
 	 || (TREE_CODE (exp) == NOP_EXPR
 	     && TREE_TYPE (TREE_OPERAND (exp, 0)) == TREE_TYPE (exp)))
     exp = TREE_OPERAND (exp, 0);
 
+  /* Preserve the original expression code.  */
+  if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (TREE_CODE (exp))))
+    C_SET_EXP_ORIGINAL_CODE (exp, C_EXP_ORIGINAL_CODE (orig_exp));
+
   /* Normally convert enums to int,
      but convert wide enums to something wider.  */
   if (code == ENUMERAL_TYPE)

gcc/testsuite/gcc.dg/Wparentheses-1.c

+/* Copyright (C) 2001 Free Software Foundation, Inc.  */
+
+/* { dg-do compile } */
+/* { dg-options -Wparentheses } */
+
+/* Source: Neil Booth, 1 Nov 2001.  PR 3170, 3422 - bogus warnings
+   about suggesting parentheses.  */
+
+int foo (int a, int b)
+{
+  int c = (a && b) || 0;	/* { dg-bogus "suggest parentheses" }  */
+  c = a && b || 0;		/* { dg-warning "suggest parentheses" }  */
+
+  return (a && b && 1) || 0;	/* { dg-bogus "suggest parentheses" }  */
+}