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

gcc/ChangeLog

@@ -1,3 +1,17 @@
+2007-07-30  Ollie Wild  <aaw@google.com>
+
+	* 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.
+
 2007-07-30  Kaveh R. Ghazi  <ghazi@caip.rutgers.edu>
 
 	* alias.c (record_set, memory_modified_1): Constify.

gcc/c-opts.c

@@ -618,6 +618,10 @@ c_common_handle_option (size_t scode, const char *arg, int value)
 	disable_builtin_function (arg);
       break;
 
+    case OPT_fdirectives_only:
+      cpp_opts->directives_only = 1;
+      break;
+
     case OPT_fdollars_in_identifiers:
       cpp_opts->dollars_in_ident = value;
       break;
@@ -1406,6 +1410,11 @@ sanitize_cpp_opts (void)
   if (flag_dump_macros == 'M')
     flag_no_output = 1;
 
+  /* By default, -fdirectives-only implies -dD.  This allows subsequent phases
+     to perform proper macro expansion.  */
+  if (cpp_opts->directives_only && !cpp_opts->preprocessed && !flag_dump_macros)
+    flag_dump_macros = 'D';
+
   /* Disable -dD, -dN and -dI if normal output is suppressed.  Allow
      -dM since at least glibc relies on -M -dM to work.  */
   /* Also, flag_no_output implies flag_no_line_commands, always.  */
@@ -1436,6 +1445,14 @@ sanitize_cpp_opts (void)
      actually output the current directory?  */
   if (flag_working_directory == -1)
     flag_working_directory = (debug_info_level != DINFO_LEVEL_NONE);
+
+  if (cpp_opts->directives_only)
+    {
+      if (warn_unused_macros)
+	error ("-fdirectives-only is incompatible with -Wunused_macros");
+      if (cpp_opts->traditional)
+	error ("-fdirectives-only is incompatible with -traditional");
+    }
 }
 
 /* Add include path with a prefix at the front of its name.  */
@@ -1519,6 +1536,8 @@ finish_options (void)
 	    }
 	}
     }
+  else if (cpp_opts->directives_only)
+    cpp_init_special_builtins (parse_in);
 
   include_cursor = 0;
   push_command_line_include ();

gcc/c-ppoutput.c

@@ -41,6 +41,8 @@ static struct
 
 /* General output routines.  */
 static void scan_translation_unit (cpp_reader *);
+static void print_lines_directives_only (int, const void *, size_t);
+static void scan_translation_unit_directives_only (cpp_reader *);
 static void scan_translation_unit_trad (cpp_reader *);
 static void account_for_newlines (const unsigned char *, size_t);
 static int dump_macro (cpp_reader *, cpp_hashnode *, void *);
@@ -75,6 +77,9 @@ preprocess_file (cpp_reader *pfile)
     }
   else if (cpp_get_options (pfile)->traditional)
     scan_translation_unit_trad (pfile);
+  else if (cpp_get_options (pfile)->directives_only
+	   && !cpp_get_options (pfile)->preprocessed)
+    scan_translation_unit_directives_only (pfile);
   else
     scan_translation_unit (pfile);
 
@@ -179,6 +184,26 @@ scan_translation_unit (cpp_reader *pfile)
     }
 }
 
+static void
+print_lines_directives_only (int lines, const void *buf, size_t size)
+{
+  print.src_line += lines;
+  fwrite (buf, 1, size, print.outf);
+}
+
+/* Writes out the preprocessed file, handling spacing and paste
+   avoidance issues.  */
+static void
+scan_translation_unit_directives_only (cpp_reader *pfile)
+{
+  struct _cpp_dir_only_callbacks cb;
+
+  cb.print_lines = print_lines_directives_only;
+  cb.maybe_print_line = maybe_print_line;
+
+  _cpp_preprocess_dir_only (pfile, &cb);
+}
+
 /* Adjust print.src_line for newlines embedded in output.  */
 static void
 account_for_newlines (const unsigned char *str, size_t len)

gcc/c.opt

@@ -523,6 +523,10 @@ fdefault-inline
 C++ ObjC++
 Inline member functions by default
 
+fdirectives-only
+C ObjC C++ ObjC++
+Preprocess directives only.
+
 fdollars-in-identifiers
 C ObjC C++ ObjC++
 Permit '$' as an identifier character

gcc/doc/cppopts.texi

@@ -518,6 +518,28 @@ Search @var{dir} only for header files requested with
 If @var{dir} begins with @code{=}, then the @code{=} will be replaced
 by the sysroot prefix; see @option{--sysroot} and @option{-isysroot}.
 
+@item -fdirectives-only
+@opindex fdirectives-only
+When preprocessing, handle directives, but do not expand macros.
+
+The option's behavior depends on the @option{-E} and @option{-fpreprocessed}
+options.
+
+With @option{-E}, preprocessing is limited to the handling of directives
+such as @code{#define}, @code{#ifdef}, and @code{#error}.  Other
+preprocessor operations, such as macro expansion and trigraph
+conversion are not performed.  In addition, the @option{-dD} option is
+implicitly enabled.
+
+With @option{-fpreprocessed}, predefinition of command line and most
+builtin macros is disabled.  Macros such as @code{__LINE__}, which are
+contextually dependent, are handled normally.  This enables compilation of
+files previously preprocessed with @code{-E -fdirectives-only}.
+
+With both @option{-E} and @option{-fpreprocessed}, the rules for
+@option{-fpreprocessed} take precedence.  This enables full preprocessing of
+files previously preprocessed with @code{-E -fdirectives-only}.
+
 @item -fdollars-in-identifiers
 @opindex fdollars-in-identifiers
 @anchor{fdollars-in-identifiers}

gcc/testsuite/ChangeLog

@@ -1,3 +1,17 @@
+2007-07-30  Ollie Wild  <aaw@google.com>
+
+	* 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.
+
 2007-07-30  Julian Brown  <julian@codesourcery.com>
 
 	* gcc.target/arm/neon/v*.c: Regenerate.

gcc/testsuite/gcc.dg/cpp/counter-2.c

@@ -0,0 +1,14 @@
+/* Copyright 2007 Free Software Foundation, Inc.
+   Contributed by Ollie Wild <aaw@google.com>.  */
+
+/* { dg-do preprocess } */
+/* { dg-options -fdirectives-only } */
+
+/* Tests __COUNTER__ macro expansion is disabled inside directives with
+   -fdirectives-only. */
+
+#ifdef __COUNTER__  /* Macro not expanded. */
+#endif
+
+#if __COUNTER__ == 0  /* { dg-error "__COUNTER__ expanded inside directive with -fdirectives-only" } */
+#endif

gcc/testsuite/gcc.dg/cpp/counter-3.c

@@ -0,0 +1,10 @@
+/* Copyright 2007 Free Software Foundation, Inc.
+   Contributed by Ollie Wild <aaw@google.com>.  */
+
+/* { dg-do preprocess } */
+/* { dg-options "-fdirectives-only -fpreprocessed" } */
+
+/* Tests __COUNTER__ macro expansion is enabled outside directives with
+   -fdirectives-only. */
+
+int zero = __COUNTER__;

gcc/testsuite/gcc.dg/cpp/dir-only-1.c

@@ -0,0 +1,73 @@
+/* Copyright 2007 Free Software Foundation, Inc.
+   Contributed by Ollie Wild <aaw@google.com>.  */
+
+/* { dg-do preprocess } */
+/* { dg-options -fdirectives-only } */
+
+/* Tests scan_translation_unit_directives_only()'s handling of corner cases. */
+
+/* Ignore directives inside block comments...
+#error directive inside block comment
+*/
+
+// Escaped newline doesn't terminate line comment \
+#error directive inside line comment
+
+/* A comment canot start inside a string. */
+const char *c1 = "/*";
+#define NOT_IN_COMMENT
+const char *c2 = "*/";
+#ifndef NOT_IN_COMMENT
+#error Comment started inside a string literal
+#endif
+
+/* Escaped newline handling. */
+int i; \
+#error ignored escaped newline
+  \
+  \
+#define BOL
+#ifndef BOL
+#error escaped newline did not preserve beginning of line
+#endif
+
+/* Handles \\ properly at the end of a string. */
+"string ends in \\"/*
+#error Missed string terminator.
+*/
+
+/* Handles macro expansion in preprocessing directives. */
+#define HEADER "dir-only-1.h"
+#include HEADER
+#ifndef GOT_HEADER
+#error Failed to include header.
+#endif
+
+/\
+*
+#define IN_COMMENT
+*/
+#ifdef IN_COMMENT
+#error Escaped newline breaks block comment initiator.
+#endif
+
+/*
+*\
+/
+#define NOT_IN_COMMENT2
+/**/
+#ifndef NOT_IN_COMMENT2
+#error Escaped newline breaks block comment terminator.
+#endif
+
+/* Test escaped newline inside character escape sequence. */
+"\\
+\"/*
+#error Missed string terminator
+*/
+
+/* Block comments don't mask trailing preprocessing
+   directive. */ #define NOT_MASKED
+#ifndef NOT_MASKED
+#error Comment masks trailing directive.
+#endif

gcc/testsuite/gcc.dg/cpp/dir-only-1.h

@@ -0,0 +1,3 @@
+/* Copyright 2007 Free Software Foundation, Inc.
+   Contributed by Ollie Wild <aaw@google.com>.  */
+#define GOT_HEADER

gcc/testsuite/gcc.dg/cpp/dir-only-2.c

@@ -0,0 +1,12 @@
+/* Copyright 2007 Free Software Foundation, Inc.
+   Contributed by Ollie Wild <aaw@google.com>.  */
+
+/* { dg-do preprocess } */
+/* { dg-options "-fpreprocessed -fdirectives-only -DNOT_SET" } */
+
+/* Tests -fdirectives-only + -fpreprocessed. */
+
+/* Check this is not defined. */
+#ifdef NOT_SET
+#error Command line macro not disabled.
+#endif

gcc/testsuite/gcc.dg/cpp/dir-only-3.c

@@ -0,0 +1,13 @@
+/* Copyright 2007 Free Software Foundation, Inc.
+   Contributed by Ollie Wild <aaw@google.com>.  */
+
+/* { dg-do preprocess } */
+/* { dg-options "-fdirectives-only -H" } */
+/* { dg-message "dir-only-3a\.h\n\[^\n\]*dir-only-3b\.h\n\[^\n\]*dir-only-3a\.h\n" "include guard check" { target *-*-* } 0 } */
+
+/* Tests include guards. */
+
+#include "dir-only-3a.h"
+#include "dir-only-3b.h"
+#include "dir-only-3b.h"
+#include "dir-only-3a.h"

gcc/testsuite/gcc.dg/cpp/dir-only-3a.h

@@ -0,0 +1,8 @@
+/* Copyright 2007 Free Software Foundation, Inc.
+   Contributed by Ollie Wild <aaw@google.com>.  */
+
+extern int outside_guard
+
+#ifndef DIR_ONLY_3A_H
+#define DIR_ONLY_3A_H
+#endif

gcc/testsuite/gcc.dg/cpp/dir-only-3b.h

@@ -0,0 +1,9 @@
+/* Copyright 2007 Free Software Foundation, Inc.
+   Contributed by Ollie Wild <aaw@google.com>.  */
+
+#ifndef DIR_ONLY_3B_H
+#define DIR_ONLY_3B_H
+
+extern int inside guard;
+
+#endif

gcc/testsuite/gcc.dg/cpp/dir-only-4.c

@@ -0,0 +1,6 @@
+/* Copyright 2007 Free Software Foundation, Inc.
+   Contributed by Ollie Wild <aaw@google.com>.  */
+
+/* { dg-do preprocess } */
+/* { dg-options "-fdirectives-only -Wunused-macros" } */
+/* { dg-error "-fdirectives-only is incompatible with -Wunused_macros\n" "-Wunused-macros check" { target *-*-* } 0 } */

gcc/testsuite/gcc.dg/cpp/dir-only-5.c

@@ -0,0 +1,6 @@
+/* Copyright 2007 Free Software Foundation, Inc.
+   Contributed by Ollie Wild <aaw@google.com>.  */
+
+/* { dg-do preprocess } */
+/* { dg-options "-fdirectives-only -traditional" } */
+/* { dg-error "-fdirectives-only is incompatible with -traditional\n" "-traditional check" { target *-*-* } 0 } */

gcc/testsuite/gcc.dg/cpp/dir-only-6.c

@@ -0,0 +1,7 @@
+/* Copyright 2007 Free Software Foundation, Inc.
+   Contributed by Ollie Wild <aaw@google.com>.  */
+
+/* { dg-do preprocess } */
+/* { dg-options -fdirectives-only } */
+
+/* { dg-error "unterminated comment" }

libcpp/ChangeLog

@@ -1,3 +1,23 @@
+2007-07-30  Ollie Wild  <aaw@google.com>
+
+	* 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.
+
 2007-07-04  Uros Bizjak  <ubizjak@gmail.com>
 
 	* traditional.c (_cpp_scan_out_logical_line): Initialize

libcpp/Makefile.in

@@ -69,14 +69,14 @@ INCLUDES = -I$(srcdir) -I. -I$(srcdir)/../include @INCINTL@ \
 
 ALL_CFLAGS = $(CFLAGS) $(WARN_CFLAGS) $(INCLUDES) $(CPPFLAGS)
 
-libcpp_a_OBJS = charset.o directives.o errors.o expr.o files.o \
-	identifiers.o init.o lex.o line-map.o macro.o mkdeps.o \
-	pch.o symtab.o traditional.o
+libcpp_a_OBJS = charset.o directives.o directives-only.o errors.o \
+	expr.o files.o identifiers.o init.o lex.o line-map.o macro.o \
+	mkdeps.o pch.o symtab.o traditional.o
 makedepend_OBJS = makedepend.o
 
-libcpp_a_SOURCES = charset.c directives.c errors.c expr.c files.c \
-	identifiers.c init.c lex.c line-map.c macro.c mkdeps.c \
-	pch.c symtab.c traditional.c
+libcpp_a_SOURCES = charset.c directives.c directives-only.c errors.c \
+	expr.c files.c identifiers.c init.c lex.c line-map.c macro.c \
+	mkdeps.c pch.c symtab.c traditional.c
 
 all: libcpp.a makedepend$(EXEEXT) $(USED_CATALOGS)
 

libcpp/directives-only.c

@@ -0,0 +1,240 @@
+/* CPP Library - directive only preprocessing for distributed compilation.
+   Copyright (C) 2007
+   Free Software Foundation, Inc.
+   Contributed by Ollie Wild <aaw@google.com>.
+
+This program is free software; you can redistribute it and/or modify it
+under the terms of the GNU General Public License as published by the
+Free Software Foundation; either version 2, or (at your option) any
+later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include "config.h"
+#include "system.h"
+#include "cpplib.h"
+#include "internal.h"
+
+/* DO (Directive only) flags. */
+#define DO_BOL		 (1 << 0) /* At the beginning of a logical line. */
+#define DO_STRING	 (1 << 1) /* In a string constant. */
+#define DO_CHAR		 (1 << 2) /* In a character constant. */
+#define DO_BLOCK_COMMENT (1 << 3) /* In a block comment. */
+#define DO_LINE_COMMENT	 (1 << 4) /* In a single line "//-style" comment. */
+
+#define DO_LINE_SPECIAL (DO_STRING | DO_CHAR | DO_LINE_COMMENT)
+#define DO_SPECIAL	(DO_LINE_SPECIAL | DO_BLOCK_COMMENT)
+
+/* Writes out the preprocessed file, handling spacing and paste
+   avoidance issues.  */
+void
+_cpp_preprocess_dir_only (cpp_reader *pfile,
+			  const struct _cpp_dir_only_callbacks *cb)
+{
+  struct cpp_buffer *buffer;
+  const unsigned char *cur, *base, *next_line, *rlimit;
+  cppchar_t c, last_c;
+  unsigned flags;
+  int lines, col;
+  source_location loc;
+
+ restart:
+  /* Buffer initialization ala _cpp_clean_line(). */
+  buffer = pfile->buffer;
+  buffer->cur_note = buffer->notes_used = 0;
+  buffer->cur = buffer->line_base = buffer->next_line;
+  buffer->need_line = false;
+
+  /* This isn't really needed.  It prevents a compiler warning, though. */
+  loc = pfile->line_table->highest_line;
+
+  /* Scan initialization. */
+  next_line = cur = base = buffer->cur;
+  rlimit = buffer->rlimit;
+  flags = DO_BOL;
+  lines = 0;
+  col = 1;
+
+  for (last_c = '\n', c = *cur; cur < rlimit; last_c = c, c = *++cur, ++col)
+    {
+      /* Skip over escaped newlines. */
+      if (__builtin_expect (c == '\\', false))
+	{
+	  const unsigned char *tmp = cur + 1;
+
+	  while (is_nvspace (*tmp) && tmp < rlimit)
+	    tmp++;
+	  if (*tmp == '\r')
+	    tmp++;
+	  if (*tmp == '\n' && tmp < rlimit)
+	    {
+	      CPP_INCREMENT_LINE (pfile, 0);
+	      lines++;
+	      col = 0;
+	      cur = tmp;
+	      c = last_c;
+	      continue;
+	    }
+	}
+
+      if (__builtin_expect (last_c == '#', false) && !(flags & DO_SPECIAL))
+	{
+	  if (c != '#' && (flags & DO_BOL))
+	  {
+	    struct line_maps *line_table;
+
+	    if (!pfile->state.skipping && next_line != base)
+	      cb->print_lines (lines, base, next_line - base);
+
+	    /* Prep things for directive handling. */
+	    buffer->next_line = cur;
+	    buffer->need_line = true;
+	    _cpp_get_fresh_line (pfile);
+
+	    /* Ensure proper column numbering for generated error messages. */
+	    buffer->line_base -= col - 1;
+
+	    _cpp_handle_directive (pfile, 0 /* ignore indented */);
+
+	    /* Sanitize the line settings.  Duplicate #include's can mess
+	       things up. */
+	    line_table = pfile->line_table;
+	    line_table->highest_location = line_table->highest_line;
+
+	    /* The if block prevents us from outputing line information when
+	       the file ends with a directive and no newline.  Note that we
+	       must use pfile->buffer, not buffer. */
+	    if (pfile->buffer->next_line < pfile->buffer->rlimit)
+	      cb->maybe_print_line (pfile->line_table->highest_line);
+
+	    goto restart;
+	  }
+
+	  flags &= ~DO_BOL;
+	  pfile->mi_valid = false;
+	}
+      else if (__builtin_expect (last_c == '/', false) \
+	       && !(flags & DO_SPECIAL) && c != '*' && c != '/')
+	{
+	  /* If a previous slash is not starting a block comment, clear the
+	     DO_BOL flag.  */
+	  flags &= ~DO_BOL;
+	  pfile->mi_valid = false;
+	}
+
+      switch (c)
+	{
+	case '/':
+	  if ((flags & DO_BLOCK_COMMENT) && last_c == '*')
+	    {
+	      flags &= ~DO_BLOCK_COMMENT;
+	      c = 0;
+	    }
+	  else if (!(flags & DO_SPECIAL) && last_c == '/')
+	    flags |= DO_LINE_COMMENT;
+	  else if (!(flags & DO_SPECIAL))
+	    /* Mark the position for possible error reporting. */
+	    LINEMAP_POSITION_FOR_COLUMN (loc, pfile->line_table, col);
+
+	  break;
+
+	case '*':
+	  if (!(flags & DO_SPECIAL))
+	    {
+	      if (last_c == '/')
+		flags |= DO_BLOCK_COMMENT;
+	      else
+		{
+		  flags &= ~DO_BOL;
+		  pfile->mi_valid = false;
+		}
+	    }
+
+	  break;
+
+	case '\'':
+	case '"':
+	  {
+	    unsigned state = (c == '"') ? DO_STRING : DO_CHAR;
+
+	    if (!(flags & DO_SPECIAL))
+	      {
+		flags |= state;
+		flags &= ~DO_BOL;
+		pfile->mi_valid = false;
+	      }
+	    else if ((flags & state) && last_c != '\\')
+	      flags &= ~state;
+
+	    break;
+	  }
+
+	case '\\':
+	  {
+	    if ((flags & (DO_STRING | DO_CHAR)) && last_c == '\\')
+	      c = 0;
+
+	    if (!(flags & DO_SPECIAL))
+	      {
+		flags &= ~DO_BOL;
+		pfile->mi_valid = false;
+	      }
+
+	    break;
+	  }
+
+	case '\n':
+	  CPP_INCREMENT_LINE (pfile, 0);
+	  lines++;
+	  col = 0;
+	  flags &= ~DO_LINE_SPECIAL;
+	  if (!(flags & DO_SPECIAL))
+	    flags |= DO_BOL;
+	  break;
+
+	case '#':
+	  next_line = cur;
+	  /* Don't update DO_BOL yet. */
+	  break;
+
+	case ' ': case '\t': case '\f': case '\v': case '\0':
+	  break;
+
+	default:
+	  if (!(flags & DO_SPECIAL))
+	    {
+	      flags &= ~DO_BOL;
+	      pfile->mi_valid = false;
+	    }
+	  break;
+	}
+    }
+
+  if (flags & DO_BLOCK_COMMENT)
+    cpp_error_with_line (pfile, CPP_DL_ERROR, loc, 0, "unterminated comment");
+
+  if (!pfile->state.skipping && cur != base)
+    {
+      /* If the file was not newline terminated, add rlimit, which is
+         guaranteed to point to a newline, to the end of our range.  */
+      if (cur[-1] != '\n')
+	{
+	  cur++;
+	  CPP_INCREMENT_LINE (pfile, 0);
+	  lines++;
+	}
+
+      cb->print_lines (lines, base, cur - base);
+    }
+
+  _cpp_pop_buffer (pfile);
+  if (pfile->buffer)
+    goto restart;
+}

libcpp/directives.c

@@ -424,8 +424,13 @@ _cpp_handle_directive (cpp_reader *pfile, int indented)
 	 does not cause '#define foo bar' to get executed when
 	 compiled with -save-temps, we recognize directives in
 	 -fpreprocessed mode only if the # is in column 1.  macro.c
-	 puts a space in front of any '#' at the start of a macro.  */
+	 puts a space in front of any '#' at the start of a macro.
+	 
+	 We exclude the -fdirectives-only case because macro expansion
+	 has not been performed yet, and block comments can cause spaces
+	 to preceed the directive.  */
       if (CPP_OPTION (pfile, preprocessed)
+	  && !CPP_OPTION (pfile, directives_only)
 	  && (indented || !(dir->flags & IN_I)))
 	{
 	  skip = 0;

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;
 

libcpp/include/cpplib.h

@@ -440,6 +440,9 @@ struct cpp_options
 
   /* True means error callback should be used for diagnostics.  */
   bool client_diagnostic;
+
+  /* True disables tokenization outside of preprocessing directives. */
+  bool directives_only;
 };
 
 /* Callback for header lookup for HEADER, which is the name of a
@@ -644,6 +647,10 @@ extern struct deps *cpp_get_deps (cpp_reader *);
    too.  If there was an error opening the file, it returns NULL.  */
 extern const char *cpp_read_main_file (cpp_reader *, const char *);
 
+/* Set up built-ins with special behavior.  Use cpp_init_builtins()
+   instead unless your know what you are doing.  */
+extern void cpp_init_special_builtins (cpp_reader *);
+
 /* Set up built-ins like __FILE__.  */
 extern void cpp_init_builtins (cpp_reader *, int);
 

libcpp/init.c

@@ -350,11 +350,8 @@ mark_named_operators (cpp_reader *pfile)
     }
 }
 
-/* Read the builtins table above and enter them, and language-specific
-   macros, into the hash table.  HOSTED is true if this is a hosted
-   environment.  */
 void
-cpp_init_builtins (cpp_reader *pfile, int hosted)
+cpp_init_special_builtins (cpp_reader *pfile)
 {
   const struct builtin *b;
   size_t n = ARRAY_SIZE (builtin_array);
@@ -363,10 +360,7 @@ cpp_init_builtins (cpp_reader *pfile, int hosted)
     n -= 2;
   else if (! CPP_OPTION (pfile, stdc_0_in_system_headers)
 	   || CPP_OPTION (pfile, std))
-    {
-      n--;
-      _cpp_define_builtin (pfile, "__STDC__ 1");
-    }
+    n--;
 
   for (b = builtin_array; b < builtin_array + n; b++)
     {
@@ -375,6 +369,20 @@ cpp_init_builtins (cpp_reader *pfile, int hosted)
       hp->flags |= NODE_BUILTIN | NODE_WARN;
       hp->value.builtin = (enum builtin_type) b->value;
     }
+}
+
+/* Read the builtins table above and enter them, and language-specific
+   macros, into the hash table.  HOSTED is true if this is a hosted
+   environment.  */
+void
+cpp_init_builtins (cpp_reader *pfile, int hosted)
+{
+  cpp_init_special_builtins (pfile);
+
+  if (!CPP_OPTION (pfile, traditional)
+      && (! CPP_OPTION (pfile, stdc_0_in_system_headers)
+	  || CPP_OPTION (pfile, std)))
+    _cpp_define_builtin (pfile, "__STDC__ 1");
 
   if (CPP_OPTION (pfile, cplusplus))
     _cpp_define_builtin (pfile, "__cplusplus 1");
@@ -622,7 +630,8 @@ post_options (cpp_reader *pfile)
      preprocessed text.  Read preprocesed source in ISO mode.  */
   if (CPP_OPTION (pfile, preprocessed))
     {
-      pfile->state.prevent_expansion = 1;
+      if (!CPP_OPTION (pfile, directives_only))
+	pfile->state.prevent_expansion = 1;
       CPP_OPTION (pfile, traditional) = 0;
     }
 

libcpp/internal.h

@@ -575,6 +575,17 @@ extern void _cpp_do_file_change (cpp_reader *, enum lc_reason, const char *,
 				 unsigned int, unsigned int);
 extern void _cpp_pop_buffer (cpp_reader *);
 
+/* In directives.c */
+struct _cpp_dir_only_callbacks
+{
+  /* Called to print a block of lines. */
+  void (*print_lines) (int, const void *, size_t);
+  void (*maybe_print_line) (source_location);
+};
+
+extern void _cpp_preprocess_dir_only (cpp_reader *,
+				      const struct _cpp_dir_only_callbacks *);
+
 /* In traditional.c.  */
 extern bool _cpp_scan_out_logical_line (cpp_reader *, cpp_macro *);
 extern bool _cpp_read_logical_line_trad (cpp_reader *);

libcpp/macro.c

@@ -265,6 +265,9 @@ _cpp_builtin_macro_text (cpp_reader *pfile, cpp_hashnode *node)
       break;
 
     case BT_COUNTER:
+      if (CPP_OPTION (pfile, directives_only) && pfile->state.in_directive)
+	cpp_error (pfile, CPP_DL_ERROR,
+	    "__COUNTER__ expanded inside directive with -fdirectives-only");
       number = pfile->counter++;
       break;
     }