c-common.c (binary_op_error): Do not allow NOP_EXPR.

* c-common.c (binary_op_error): Do not allow NOP_EXPR.
	(c_common_truthvalue_conversion): Handle NOP_EXPR the same as
	CONVERT_EXPR.
	(check_function_arguments_recurse): Allow both NOP_EXPR and
	CONVERT_EXPR but check conversions preserve precision.
	* c-typeck.c (pointer_diff): Allow both NOP_EXPR and CONVERT_EXPR
	but check conversions preserve precision.
	(build_unary_op): Don't allow NOP_EXPR.  Use gcc_unreachable () in
	default case.

testsuite:
	* gcc.dg/format/cast-1.c: New test.

From-SVN: r108020

gcc/ChangeLog

@@ -1,3 +1,15 @@
+2005-12-04  Joseph S. Myers  <joseph@codesourcery.com>
+
+	* c-common.c (binary_op_error): Do not allow NOP_EXPR.
+	(c_common_truthvalue_conversion): Handle NOP_EXPR the same as
+	CONVERT_EXPR.
+	(check_function_arguments_recurse): Allow both NOP_EXPR and
+	CONVERT_EXPR but check conversions preserve precision.
+	* c-typeck.c (pointer_diff): Allow both NOP_EXPR and CONVERT_EXPR
+	but check conversions preserve precision.
+	(build_unary_op): Don't allow NOP_EXPR.  Use gcc_unreachable () in
+	default case.
+
 2005-12-04  Roger Sayle  <roger@eyesopen.com>
 
 	PR c/7776

gcc/c-common.c

@@ -1862,8 +1862,7 @@ min_precision (tree value, int unsignedp)
 }
 
 /* Print an error message for invalid operands to arith operation
-   CODE.  NOP_EXPR is used as a special case (see
+   CODE.  */
-   c_common_truthvalue_conversion).  */
 
 void
 binary_op_error (enum tree_code code)
@@ -1872,10 +1871,6 @@ binary_op_error (enum tree_code code)
 
   switch (code)
     {
-    case NOP_EXPR:
-      error ("invalid truth-value expression");
-      return;
-
     case PLUS_EXPR:
       opname = "+"; break;
     case MINUS_EXPR:
@@ -2467,13 +2462,12 @@ c_common_truthvalue_conversion (tree expr)
 		c_common_truthvalue_conversion (TREE_OPERAND (expr, 2)));
 
     case CONVERT_EXPR:
+    case NOP_EXPR:
       /* Don't cancel the effect of a CONVERT_EXPR from a REFERENCE_TYPE,
 	 since that affects how `default_conversion' will behave.  */
       if (TREE_CODE (TREE_TYPE (expr)) == REFERENCE_TYPE
 	  || TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == REFERENCE_TYPE)
 	break;
-      /* Fall through....  */
-    case NOP_EXPR:
       /* If this is widening the argument, we can ignore it.  */
       if (TYPE_PRECISION (TREE_TYPE (expr))
 	  >= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (expr, 0))))
@@ -5614,7 +5608,9 @@ check_function_arguments_recurse (void (*callback)
 				  void *ctx, tree param,
 				  unsigned HOST_WIDE_INT param_num)
 {
-  if (TREE_CODE (param) == NOP_EXPR)
+  if ((TREE_CODE (param) == NOP_EXPR || TREE_CODE (param) == CONVERT_EXPR)
+      && (TYPE_PRECISION (TREE_TYPE (param))
+	  == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (param, 0)))))
     {
       /* Strip coercion.  */
       check_function_arguments_recurse (callback, ctx,

gcc/c-typeck.c

@@ -2601,8 +2601,18 @@ pointer_diff (tree op0, tree op1)
      different mode in place.)
      So first try to find a common term here 'by hand'; we want to cover
      at least the cases that occur in legal static initializers.  */
-  con0 = TREE_CODE (op0) == NOP_EXPR ? TREE_OPERAND (op0, 0) : op0;
+  if ((TREE_CODE (op0) == NOP_EXPR || TREE_CODE (op0) == CONVERT_EXPR)
-  con1 = TREE_CODE (op1) == NOP_EXPR ? TREE_OPERAND (op1, 0) : op1;
+      && (TYPE_PRECISION (TREE_TYPE (op0))
+	  == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op0, 0)))))
+    con0 = TREE_OPERAND (op0, 0);
+  else
+    con0 = op0;
+  if ((TREE_CODE (op1) == NOP_EXPR || TREE_CODE (op1) == CONVERT_EXPR)
+      && (TYPE_PRECISION (TREE_TYPE (op1))
+	  == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op1, 0)))))
+    con1 = TREE_OPERAND (op1, 0);
+  else
+    con1 = op1;
 
   if (TREE_CODE (con0) == PLUS_EXPR)
     {
@@ -2761,9 +2771,6 @@ build_unary_op (enum tree_code code, tree xarg, int flag)
       arg = c_objc_common_truthvalue_conversion (arg);
       return invert_truthvalue (arg);
 
-    case NOP_EXPR:
-      break;
-
     case REALPART_EXPR:
       if (TREE_CODE (arg) == COMPLEX_CST)
 	return TREE_REALPART (arg);
@@ -2941,7 +2948,7 @@ build_unary_op (enum tree_code code, tree xarg, int flag)
       return val;
 
     default:
-      break;
+      gcc_unreachable ();
     }
 
   if (argtype == 0)

gcc/testsuite/ChangeLog

@@ -1,3 +1,7 @@
+2005-12-04  Joseph S. Myers  <joseph@codesourcery.com>
+
+	* gcc.dg/format/cast-1.c: New test.
+
 2005-12-04  Roger Sayle  <roger@eyesopen.com>
 
 	PR c/7776

gcc/testsuite/gcc.dg/format/cast-1.c

@@ -0,0 +1,16 @@
+/* Test for strings cast through integer types: should not be treated
+   as format strings unless the types are of the same width as
+   pointers (intptr_t or similar).  */
+/* Origin: Joseph Myers <joseph@codesourcery.com> */
+/* { dg-do compile } */
+/* { dg-options "-Wformat" } */
+
+#include "format.h"
+
+void
+f (int x)
+{
+  printf("%s", x); /* { dg-warning "format" } */
+  printf((char *)(size_t)"%s", x); /* { dg-warning "format" } */
+  printf((char *)(char)"%s", x);
+}