2007-02-15  Manuel Lopez-Ibanez  <manu@gcc.gnu.org>

	PR c/26494
	* doc/invoke.texi (Warning Options): Remove
	-Werror-implicit-function-declaration.
	(Wimplicit-function-declaration): Update description.
	* opts.c (common_handle_option): Move handling of -Werror=* to...
	(enable_warning_as_error): ...here.
	* opts.h (enable_warning_as_error): Declare.
	* c-decl.c (implicit_decl_warning): Unless
	-Wno-implicit-function-declaration is given, emit a pedwarn if
	-std=c99 or emit a warning if -Wimplicit-function-declaration.
	* c.opt (Wimplicit-function-declaration): Replace
	mesg_implicit_function_declaration with
	warn_implicit_function_declaration.
	* c-opts.c (c_common_handle_option):
	-Werror-implicit-function-declaration is exactly equal as
	-Werror=implicit-function-declaration.
	(set_Wimplicit): Replace mesg_implicit_function_declaration with
	warn_implicit_function_declaration.
	(c_common_post_options): -Wimplict-function-declaration is enabled
	by default by -std=c99, otherwise is disabled by default.
	* c-objc-common.c (c_objc_common_init): Remove flawed logic.
testsuite/
	* gcc.dg/Wimplicit-function-declaration-c89.c: New.
	* gcc.dg/Wimplicit-function-declaration-c89-default.c: New.
	* gcc.dg/Wimplicit-function-declaration-c89-pedantic.c: New.
	* gcc.dg/Wimplicit-function-declaration-c99.c: New.
	* gcc.dg/Wimplicit-function-declaration-c99-pedantic.c: New.
	* gcc.dg/Werror-implicit-function-declaration.c: New.

From-SVN: r122017