directives-only.c: New file.

libcpp/
	* directives-only.c: New file.
	* internal.h (struct _cpp_dir_only_callbacks): New.
	(_cpp_preprocess_dir_only): New function.
	* directives.c (_cpp_handle_directive): Check directives_only before
	disabling execution of indented directives.
	* files.c (_cpp_stack_file): Add directives_only check.
	* include/cpplib.h (struct cpp_options): Add directives_only.
	(cpp_init_special_builtins): New function.
	* init.c (cpp_init_special_builtins): New function.
	(cpp_init_builtins): Move builtin_array initialization to
	cpp_init_special_builtins.
	(post_options): Check directives_only before setting
	pfile->state.prevent_expansion = 1.
	* macro.c (_cpp_builtin_macro_text): Print an error if __COUNTER__
	is expanded inside a directive while -fdirectives-only is enabled.
	* Makefile.in (libcpp_a_OBJS): Add directives-only.o.
	(libcpp_a_SOURCES): Add directives-only.c.

	gcc/
	* c-ppoutput.c (print_lines_directives_only): New function.
	(scan_translation_unit_directives_only): New function.
	(preprocess_file): Add call to scan_translation_unit_directives_only.
	* c-opts.c (c_common_handle_option): Add OPT_fdirectives_only.
	(sanitize_cpp_opts): Add default flag_dump_macros setting for
	-fdirectives-only.  Add errors for -fdirectives-only conflict with
	-Wunused-macros and -traditional.
	(finish_options): Add builtin macro initialization for
	-fdirectives-only + -fpreprocessed.
	* c.opt (fdirectives-only): New.
	* doc/cppopts.texi (fdirectives-only): New.

	gcc/testsuite/
	* gcc.dg/cpp/counter-2.c: New test.
	* gcc.dg/cpp/counter-3.c: New test.
	* gcc.dg/cpp/dir-only-1.c: New test.
	* gcc.dg/cpp/dir-only-1.h: New file.
	* gcc.dg/cpp/dir-only-2.c: New test.
	* gcc.dg/cpp/dir-only-3.c: New test.
	* gcc.dg/cpp/dir-only-3a.h: New file.
	* gcc.dg/cpp/dir-only-3b.h: New file.
	* gcc.dg/cpp/dir-only-4.c: New test.
	* gcc.dg/cpp/dir-only-5.c: New test.
	* gcc.dg/cpp/dir-only-6.c: New test.

From-SVN: r127066

libcpp/files.c

@@ -791,7 +791,8 @@ _cpp_stack_file (cpp_reader *pfile, _cpp_file *file, bool import)
 
   /* Stack the buffer.  */
   buffer = cpp_push_buffer (pfile, file->buffer, file->st.st_size,
-			    CPP_OPTION (pfile, preprocessed));
+			    CPP_OPTION (pfile, preprocessed)
+			    && !CPP_OPTION (pfile, directives_only));
   buffer->file = file;
   buffer->sysp = sysp;