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, 0 deletions

diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index fa9ed7f..b3fe752 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -3396,6 +3396,12 @@ like @code{unsigned ui = -1}; and conversions to smaller types, like
 ((int) x)} and @code{ui = (unsigned) -1}, or if the value is not
 changed by the conversion like in @code{abs (2.0)}.
 
+For C++, also warn for conversions between @code{NULL} and non-pointer
+types; confusing overload resolution for user-defined conversions; and
+conversions that will never use a type conversion operator:
+conversions to @code{void}, the same type, a base class or a reference
+to them.
+
 @item -Wempty-body
 @opindex Wempty-body
 An empty body occurs in an @samp{if}, @samp{else} or @samp{do while}