* diagnostic.h (diagnostic_override_option_index): New macro to
	set a diagnostic's option_index.
	* c-tree.h (c_cpp_error): Add warning reason argument.
	* opts.c (_warning_as_error_callback): New.
	(register_warning_as_error_callback): Store callback for
	warnings enabled via enable_warning_as_error.
	(enable_warning_as_error): Call callback, minor code tidy.
	* opts.h (register_warning_as_error_callback): Declare.
	* c-opts.c (warning_as_error_callback): New, set cpp_opts flag in
	response to -Werror=.
	(c_common_init_options): Register warning_as_error_callback in opts.c.
	* common.opt: Add -Wno-cpp option.
	* c-common.c (struct reason_option_codes_t): Map cpp warning
	reason codes to gcc option indexes.
	* (c_option_controlling_cpp_error): New function, lookup the gcc
	option index for a cpp warning reason code.
	* (c_cpp_error): Add warning reason argument, call
	c_option_controlling_cpp_error for diagnostic_override_option_index.
	* doc/invoke.texi: Document -Wno-cpp.

	* cpp.c (cb_cpp_error): Add warning reason argument, set a value
	for diagnostic_override_option_index if CPP_W_WARNING_DIRECTIVE.

	* directives.c (do_diagnostic): Add warning reason argument,
	call appropriate error reporting function for code.
	(directive_diagnostics): Call specific warning functions with
	warning reason where appropriate.
	(do_error, do_warning, do_pragma_dependency): Add warning reason
	argument to do_diagnostic calls.
	* macro.c (_cpp_warn_if_unused_macro, enter_macro_context,
	_cpp_create_definition): Call specific warning functions with
        warning reason where appropriate.
	* Makefile.in: Add new diagnostic functions to gettext translations.
	* include/cpplib.h (struct cpp_callbacks): Add warning reason code
	to error callback.
	(CPP_DL_WARNING, CPP_DL_WARNING_SYSHDR, CPP_DL_PEDWARN, CPP_DL_ERROR,
	CPP_DL_ICE, CPP_DL_NOTE, CPP_DL_FATAL): Replace macros with enums.
	(CPP_W_NONE, CPP_W_DEPRECATED, CPP_W_COMMENTS,
	CPP_W_MISSING_INCLUDE_DIRS, CPP_W_TRIGRAPHS, CPP_W_MULTICHAR,
	CPP_W_TRADITIONAL, CPP_W_LONG_LONG, CPP_W_ENDIF_LABELS,
	CPP_W_NUM_SIGN_CHANGE, CPP_W_VARIADIC_MACROS,
	CPP_W_BUILTIN_MACRO_REDEFINED, CPP_W_DOLLARS, CPP_W_UNDEF,
	CPP_W_UNUSED_MACROS, CPP_W_CXX_OPERATOR_NAMES, CPP_W_NORMALIZE,
	CPP_W_INVALID_PCH, CPP_W_WARNING_DIRECTIVE): New enums for cpp
	warning reason codes.
	(cpp_warning, cpp_pedwarning, cpp_warning_syshdr,
	cpp_warning_with_line, cpp_pedwarning_with_line,
	cpp_warning_with_line_syshdr): New specific error reporting functions.
	* pch.c (cpp_valid_state): Call specific warning functions with
        warning reason where appropriate.
	* errors.c (cpp_diagnostic, cpp_diagnostic_with_line): New central
	diagnostic handlers.
	(cpp_warning, cpp_pedwarning, cpp_warning_syshdr,
	cpp_warning_with_line, cpp_pedwarning_with_line,
	cpp_warning_with_line_syshdr): New specific error reporting functions.
	* expr.c (cpp_classify_number, eval_token, num_unary_op): Call
	specific warning functions with warning reason where appropriate.
	* lex.c (_cpp_process_line_notes, _cpp_skip_block_comment,
	warn_about_normalization, lex_identifier_intern, lex_identifier,
	_cpp_lex_direct): Ditto.
	* charset.c (_cpp_valid_ucn, convert_hex, convert_escape,
	narrow_str_to_charconst): Ditto.

	* gcc.dg/cpp/warn-undef-2.c: New.
	* gcc.dg/cpp/warn-traditional-2.c: New.
	* gcc.dg/cpp/warn-comments-2.c: New.
	* gcc.dg/cpp/warning-directive-1.c: New.
	* gcc.dg/cpp/warn-long-long.c: New.
	* gcc.dg/cpp/warn-traditional.c: New.
	* gcc.dg/cpp/warn-variadic-2.c: New.
	* gcc.dg/cpp/warn-undef.c: New.
	* gcc.dg/cpp/warn-normalized-1.c: New.
	* gcc.dg/cpp/warning-directive-2.c: New.
	* gcc.dg/cpp/warn-long-long-2.c: New.
	* gcc.dg/cpp/warn-variadic.c: New.
	* gcc.dg/cpp/warn-normalized-2.c: New.
	* gcc.dg/cpp/warning-directive-3.c: New.
	* gcc.dg/cpp/warn-deprecated-2.c: New.
	* gcc.dg/cpp/warn-trigraphs-1.c: New.
	* gcc.dg/cpp/warn-multichar-2.c: New.
	* gcc.dg/cpp/warn-normalized-3.c: New.
	* gcc.dg/cpp/warning-directive-4.c: New.
	* gcc.dg/cpp/warn-unused-macros.c: New.
	* gcc.dg/cpp/warn-trigraphs-2.c: New.
	* gcc.dg/cpp/warn-cxx-compat-2.c: New.
	* gcc.dg/cpp/warn-cxx-compat.c: New.
	* gcc.dg/cpp/warn-redefined.c: New.
	* gcc.dg/cpp/warn-trigraphs-3.c: New.
	* gcc.dg/cpp/warn-unused-macros-2.c: New.
	* gcc.dg/cpp/warn-deprecated.c: New.
	* gcc.dg/cpp/warn-trigraphs-4.c: New.
	* gcc.dg/cpp/warn-redefined-2.c: New.
	* gcc.dg/cpp/warn-comments.c: New.
	* gcc.dg/cpp/warn-multichar.c: New.
	* g++.dg/cpp/warning-directive-1.C: New.
	* g++.dg/cpp/warning-directive-2.C: New.
	* g++.dg/cpp/warning-directive-3.C: New.
	* g++.dg/cpp/warning-directive-4.C: New.
	* gfortran.dg/warning-directive-1.F90: New.
	* gfortran.dg/warning-directive-3.F90: New.
	* gfortran.dg/warning-directive-2.F90: New.
	* gfortran.dg/warning-directive-4.F90: New.

From-SVN: r158079