re PR c++/14710 (Warning about useless casts)

re PR c++/14710 (Warning about useless casts)

2012-03-16  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/14710
	* doc/invoke.texi: Document -Wuseless-cast.

/c-family
2012-03-16  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/14710
	* c.opt ([Wuseless-cast]): Add.

/cp
2012-03-16  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/14710
	* cp-tree.h (maybe_warn_about_useless_cast): Declare.
	* typeck.c (maybe_warn_about_useless_cast): Define.
	(build_reinterpret_cast, build_const_cast,
	build_static_cast, cp_build_c_cast): Use it.
	* rtti.c (build_dynamic_cast): Likewise.
	* pt.c (tsubst_copy_and_build, case CAST_EXPR): Increment/decrement
	c_inhibit_evaluation_warnings before/after the build_* calls.

/testsuite
2012-03-16  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/14710
	* g++.dg/warn/Wuseless-cast.C: New.

From-SVN: r185524