PR c++/19564
	PR c++/19756
gcc/:
	* c-typeck.c (parser_build_binary_op): Move parentheses warnings
	to warn_about_parentheses in c-common.c.
	* c-common.c (warn_about_parentheses): New function.
	* c-common.h (warn_about_parentheses): Declare.
	* doc/invoke.texi (Warning Options): Update -Wparentheses
	description.
gcc/cp/:
	* parser.c (cp_parser_expression_stack_entry): Add field
	lhs_type.
	(cp_parser_binary_expression): Track tree code of left hand side
	of expression.  Use it when calling build_x_binary_op.
	(cp_parser_selection_statement): Add if_p parameter.  Change all
	callers.  Warn about ambiguous else.
	(cp_parser_statement): Add if_p parameter.  Change all callers.
	(cp_parser_implicitly_scoped_statement): Likewise.
	* typeck.c (build_x_binary_op): Add parameters arg1_code and
	arg2_code.  Change all callers.  Call warn_about_parentheses.
	* cp-tree.h (build_x_binary_op): Update declaration.
gcc/testsuite/:
	* g++.dg/warn/Wparentheses-5.C: New test.
	* g++.dg/warn/Wparentheses-6.C: New test.
	* g++.dg/warn/Wparentheses-7.C: New test.
	* g++.dg/warn/Wparentheses-8.C: New test.
	* g++.dg/warn/Wparentheses-9.C: New test.
	* g++.dg/warn/Wparentheses-10.C: New test.
	* g++.dg/warn/Wparentheses-11.C: New test.
	* g++.dg/warn/Wparentheses-12.C: New test.
	* g++.dg/warn/Wparentheses-13.C: New test.
	* g++.dg/warn/Wparentheses-14.C: New test.
	* g++.dg/warn/Wparentheses-15.C: New test.
	* g++.dg/warn/Wparentheses-16.C: New test.
	* g++.dg/warn/Wparentheses-17.C: New test.
	* g++.dg/warn/Wparentheses-18.C: New test.
	* g++.dg/warn/Wparentheses-19.C: New test.
	* g++.dg/warn/Wparentheses-20.C: New test.
	* g++.dg/warn/Wparentheses-21.C: New test.
libstdc++-v3/:
	* include/bits/locale_facets.tcc (num_get<>::_M_extract_float):
	Add parentheses around && within || to avoid warning.
	(num_get<>::_M_extract_int): Likewise.
	(money_get<>::_M_extract): Likewise.
	(num_get<>::do_get(iter_type, iter_type, ios_base&,
	ios_base::iostate&, void*&)): Add parentheses around & within | to
	avoid warning.
	(num_put<>::do_put(iter_type, ios_base&, char_type, const void*)):
	Likewise.
	* include/bits/streambuf_iterator.h (istreambuf_iterator::equal):
	Add parentheses around && within || to avoid warning.
	* libsupc++/tinfo.cc (__do_dyncast): Likewise.
	* src/locale.cc (locale::_S_normalize_category): Likewise.
	* include/bits/stl_tree.h (_Rb_tree<>::_M_insert_unique): Add
	braces to avoid ambiguous else warning.
	* src/strstream.cc (strstreambuf::_M_free): Likewise.
	* src/tree.cc (_Rb_tree_rebalance_for_erase): Likewise.

From-SVN: r119855