invoke.texi (-Wconversion): Document warnings specific to C++.

2007-03-16  Manuel Lopez-Ibanez  <manu@gcc.gnu.org>

	* doc/invoke.texi (-Wconversion): Document warnings specific to C++.
	* c-common.c (convert_and_check): Move warning logic to...
	(warnings_for_convert_and_check): ...here. Define.
	* c-common.h (warnings_for_convert_and_check): Declare.
cp/
	* cvt.c (cp_convert_and_check) : Define.
	* cp-tree.h (cp_convert_and_check): Declare.
	* call.c (convert_conversion_warnings): Rename to
	conversion_null_warnings.  The warning for floating-point to
	integer is handled by convert_and_check in convert_like_real.
	(convert_like_real): convert_conversion_warnings was renamed as
	conversion_null_warnings.
	* typeck.c (build_binary_op): Use cp_convert_and_check to warn for
	overflow and changes of value during conversion.
testsuite/
	* g++.dg/warn/Wconversion-integer.C: New
	* g++.dg/warn/Wconversion-real.C: New.
	* g++.dg/warn/Wconversion-real-integer.C: New.
	* g++.dg/warn/conv2.C: Updated.

From-SVN: r123005

1 files changed, 6 insertions, 16 deletions

diff --git a/gcc/cp/call.c b/gcc/cp/call.c
index 9d25298..8218ed4 100644
--- a/gcc/cp/call.c
+++ b/gcc/cp/call.c
@@ -4245,11 +4245,12 @@ build_temp (tree expr, tree type, int flags,
   return expr;
 }
 
-/* Perform warnings about conversion of EXPR to type TOTYPE.
+/* Perform warnings about peculiar, but valid, conversions from/to NULL.
+   EXPR is implicitly converted to type TOTYPE.
    FN and ARGNUM are used for diagnostics.  */
 
 static void
-convert_conversion_warnings (tree totype, tree expr, tree fn, int argnum)
+conversion_null_warnings (tree totype, tree expr, tree fn, int argnum)
 {
   tree t = non_reference (totype);
 
@@ -4263,19 +4264,8 @@ convert_conversion_warnings (tree totype, tree expr, tree fn, int argnum)
 	warning (OPT_Wconversion, "converting to non-pointer type %qT from NULL", t);
     }
 
-  /* Warn about assigning a floating-point type to an integer type.  */
-  if (TREE_CODE (TREE_TYPE (expr)) == REAL_TYPE
-      && TREE_CODE (t) == INTEGER_TYPE)
-    {
-      if (fn)
-	warning (OPT_Wconversion, "passing %qT for argument %P to %qD",
-		 TREE_TYPE (expr), argnum, fn);
-      else
-	warning (OPT_Wconversion, "converting to %qT from %qT", t, TREE_TYPE (expr));
-    }
-
   /* Issue warnings if "false" is converted to a NULL pointer */
-  if (expr == boolean_false_node && fn && POINTER_TYPE_P (t))
+  else if (expr == boolean_false_node && fn && POINTER_TYPE_P (t))
     warning (OPT_Wconversion,
 	     "converting %<false%> to pointer type for argument %P of %qD",
 	     argnum, fn);
@@ -4328,7 +4318,7 @@ convert_like_real (conversion *convs, tree expr, tree fn, int argnum,
     }
 
   if (issue_conversion_warnings)
-    convert_conversion_warnings (totype, expr, fn, argnum);
+    conversion_null_warnings (totype, expr, fn, argnum);
 
   switch (convs->kind)
     {
@@ -4415,7 +4405,7 @@ convert_like_real (conversion *convs, tree expr, tree fn, int argnum,
 
   expr = convert_like_real (convs->u.next, expr, fn, argnum,
 			    convs->kind == ck_ref_bind ? -1 : 1,
-			    /*issue_conversion_warnings=*/false,
+			    convs->kind == ck_ref_bind ? issue_conversion_warnings : false, 
 			    c_cast_p);
   if (expr == error_mark_node)
     return error_mark_node;