PR c/10604
* c-common.c (warn_sign_compare): Initialize to -1.
* c-opts.c (c_common_init_options): Don't set warn_sign_compare here.
(c_common_decode_option <OPT_Wall>): Set warn_sign_compare
for C++ only.
(c_common_post_options): Set warn_sign_compare from extra_warnings
if it's still -1 at this point.
* toplev.c (maybe_warn_unused_parameter): New static variable.
(set_Wextra): New static function.
(W_options): Remove "extra".
(decode_W_option): Call set_Wextra.
(independent_decode_option): Likewise.
(set_Wunused): Cooperate with set_Wextra in setting
warn_unused_parameter.
(rest_of_compilation): No need to check extra_warnings as
well as warn_uninitialized.
* c-typeck.c (build_binary_op, build_conditional_expr):
No need to check extra_warnings as well as warn_sign_compare.
(internal_build_compound_expr): No need to check extra_warnings
as well as warn_unused_value.
* function.c (expand_function_end): No need to check extra_warnings
as well as warn_unused_parameter.
* stmt.c (expand_expr_stmt_value): No need to check extra_warnings
as well as warn_unused_value.
* cp/typeck.c (build_x_compound_expr): No need to check
extra_warnings as well as warn_unused_value.
* doc/invoke.texi: Clarify documentation of -Wsign-compare.
* gcc.dg/compare7.c, g++.dg/warn/compare1.C: New testcases.
* Makefile.in: Disable -Werror for gengtype-lex.o.
From-SVN: r66436
