--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libcpp/directives.c	Fri Jul 17 14:47:48 2009 +0900
@@ -0,0 +1,2410 @@
+/* CPP Library. (Directive handling.)
+   Copyright (C) 1986, 1987, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
+   1999, 2000, 2001, 2002, 2003, 2004, 2005,
+   2007, 2008, 2009 Free Software Foundation, Inc.
+   Contributed by Per Bothner, 1994-95.
+   Based on CCCP program by Paul Rubin, June 1986
+   Adapted to ANSI C, Richard Stallman, Jan 1987
+
+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 3, 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; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#include "config.h"
+#include "system.h"
+#include "cpplib.h"
+#include "internal.h"
+#include "mkdeps.h"
+#include "obstack.h"
+
+/* Stack of conditionals currently in progress
+   (including both successful and failing conditionals).  */
+struct if_stack
+{
+  struct if_stack *next;
+  linenum_type line;		/* Line where condition started.  */
+  const cpp_hashnode *mi_cmacro;/* macro name for #ifndef around entire file */
+  bool skip_elses;		/* Can future #else / #elif be skipped?  */
+  bool was_skipping;		/* If were skipping on entry.  */
+  int type;			/* Most recent conditional for diagnostics.  */
+};
+
+/* Contains a registered pragma or pragma namespace.  */
+typedef void (*pragma_cb) (cpp_reader *);
+struct pragma_entry
+{
+  struct pragma_entry *next;
+  const cpp_hashnode *pragma;	/* Name and length.  */
+  bool is_nspace;
+  bool is_internal;
+  bool is_deferred;
+  bool allow_expansion;
+  union {
+    pragma_cb handler;
+    struct pragma_entry *space;
+    unsigned int ident;
+  } u;
+};
+
+/* Values for the origin field of struct directive.  KANDR directives
+   come from traditional (K&R) C.  STDC89 directives come from the
+   1989 C standard.  EXTENSION directives are extensions.  */
+#define KANDR		0
+#define STDC89		1
+#define EXTENSION	2
+
+/* Values for the flags field of struct directive.  COND indicates a
+   conditional; IF_COND an opening conditional.  INCL means to treat
+   "..." and <...> as q-char and h-char sequences respectively.  IN_I
+   means this directive should be handled even if -fpreprocessed is in
+   effect (these are the directives with callback hooks).
+
+   EXPAND is set on directives that are always macro-expanded.  */
+#define COND		(1 << 0)
+#define IF_COND		(1 << 1)
+#define INCL		(1 << 2)
+#define IN_I		(1 << 3)
+#define EXPAND		(1 << 4)
+#define DEPRECATED	(1 << 5)
+
+/* Defines one #-directive, including how to handle it.  */
+typedef void (*directive_handler) (cpp_reader *);
+typedef struct directive directive;
+struct directive
+{
+  directive_handler handler;	/* Function to handle directive.  */
+  const uchar *name;		/* Name of directive.  */
+  unsigned short length;	/* Length of name.  */
+  unsigned char origin;		/* Origin of directive.  */
+  unsigned char flags;	        /* Flags describing this directive.  */
+};
+
+/* Forward declarations.  */
+
+static void skip_rest_of_line (cpp_reader *);
+static void check_eol (cpp_reader *);
+static void start_directive (cpp_reader *);
+static void prepare_directive_trad (cpp_reader *);
+static void end_directive (cpp_reader *, int);
+static void directive_diagnostics (cpp_reader *, const directive *, int);
+static void run_directive (cpp_reader *, int, const char *, size_t);
+static char *glue_header_name (cpp_reader *);
+static const char *parse_include (cpp_reader *, int *, const cpp_token ***);
+static void push_conditional (cpp_reader *, int, int, const cpp_hashnode *);
+static unsigned int read_flag (cpp_reader *, unsigned int);
+static bool strtolinenum (const uchar *, size_t, linenum_type *, bool *);
+static void do_diagnostic (cpp_reader *, int, int);
+static cpp_hashnode *lex_macro_node (cpp_reader *, bool);
+static int undefine_macros (cpp_reader *, cpp_hashnode *, void *);
+static void do_include_common (cpp_reader *, enum include_type);
+static struct pragma_entry *lookup_pragma_entry (struct pragma_entry *,
+                                                 const cpp_hashnode *);
+static int count_registered_pragmas (struct pragma_entry *);
+static char ** save_registered_pragmas (struct pragma_entry *, char **);
+static char ** restore_registered_pragmas (cpp_reader *, struct pragma_entry *,
+                                           char **);
+static void do_pragma_once (cpp_reader *);
+static void do_pragma_poison (cpp_reader *);
+static void do_pragma_system_header (cpp_reader *);
+static void do_pragma_dependency (cpp_reader *);
+static void do_linemarker (cpp_reader *);
+static const cpp_token *get_token_no_padding (cpp_reader *);
+static const cpp_token *get__Pragma_string (cpp_reader *);
+static void destringize_and_run (cpp_reader *, const cpp_string *);
+static int parse_answer (cpp_reader *, struct answer **, int);
+static cpp_hashnode *parse_assertion (cpp_reader *, struct answer **, int);
+static struct answer ** find_answer (cpp_hashnode *, const struct answer *);
+static void handle_assertion (cpp_reader *, const char *, int);
+
+/* This is the table of directive handlers.  It is ordered by
+   frequency of occurrence; the numbers at the end are directive
+   counts from all the source code I have lying around (egcs and libc
+   CVS as of 1999-05-18, plus grub-0.5.91, linux-2.2.9, and
+   pcmcia-cs-3.0.9).  This is no longer important as directive lookup
+   is now O(1).  All extensions other than #warning, #include_next,
+   and #import are deprecated.  The name is where the extension
+   appears to have come from.  */
+
+#define DIRECTIVE_TABLE							\
+D(define,	T_DEFINE = 0,	KANDR,     IN_I)	   /* 270554 */ \
+D(include,	T_INCLUDE,	KANDR,     INCL | EXPAND)  /*  52262 */ \
+D(endif,	T_ENDIF,	KANDR,     COND)	   /*  45855 */ \
+D(ifdef,	T_IFDEF,	KANDR,     COND | IF_COND) /*  22000 */ \
+D(if,		T_IF,		KANDR, COND | IF_COND | EXPAND) /*  18162 */ \
+D(else,		T_ELSE,		KANDR,     COND)	   /*   9863 */ \
+D(ifndef,	T_IFNDEF,	KANDR,     COND | IF_COND) /*   9675 */ \
+D(undef,	T_UNDEF,	KANDR,     IN_I)	   /*   4837 */ \
+D(line,		T_LINE,		KANDR,     EXPAND)	   /*   2465 */ \
+D(elif,		T_ELIF,		STDC89,    COND | EXPAND)  /*    610 */ \
+D(error,	T_ERROR,	STDC89,    0)		   /*    475 */ \
+D(pragma,	T_PRAGMA,	STDC89,    IN_I)	   /*    195 */ \
+D(warning,	T_WARNING,	EXTENSION, 0)		   /*     22 */ \
+D(include_next,	T_INCLUDE_NEXT,	EXTENSION, INCL | EXPAND)  /*     19 */ \
+D(ident,	T_IDENT,	EXTENSION, IN_I | DEPRECATED) /*     11 */ \
+D(import,	T_IMPORT,	EXTENSION, INCL | EXPAND)  /* 0 ObjC */	\
+D(assert,	T_ASSERT,	EXTENSION, DEPRECATED)	   /* 0 SVR4 */	\
+D(unassert,	T_UNASSERT,	EXTENSION, DEPRECATED)	   /* 0 SVR4 */	\
+D(sccs,		T_SCCS,		EXTENSION, IN_I | DEPRECATED) /* 0 SVR4? */
+
+/* #sccs is synonymous with #ident.  */
+#define do_sccs do_ident
+
+/* Use the table to generate a series of prototypes, an enum for the
+   directive names, and an array of directive handlers.  */
+
+#define D(name, t, o, f) static void do_##name (cpp_reader *);
+DIRECTIVE_TABLE
+#undef D
+
+#define D(n, tag, o, f) tag,
+enum
+{
+  DIRECTIVE_TABLE
+  N_DIRECTIVES
+};
+#undef D
+
+#define D(name, t, origin, flags) \
+{ do_##name, (const uchar *) #name, \
+  sizeof #name - 1, origin, flags },
+static const directive dtable[] =
+{
+DIRECTIVE_TABLE
+};
+#undef D
+#undef DIRECTIVE_TABLE
+
+/* Wrapper struct directive for linemarkers.
+   The origin is more or less true - the original K+R cpp
+   did use this notation in its preprocessed output.  */
+static const directive linemarker_dir =
+{
+  do_linemarker, UC"#", 1, KANDR, IN_I
+};
+
+#define SEEN_EOL() (pfile->cur_token[-1].type == CPP_EOF)
+
+/* Skip any remaining tokens in a directive.  */
+static void
+skip_rest_of_line (cpp_reader *pfile)
+{
+  /* Discard all stacked contexts.  */
+  while (pfile->context->prev)
+    _cpp_pop_context (pfile);
+
+  /* Sweep up all tokens remaining on the line.  */
+  if (! SEEN_EOL ())
+    while (_cpp_lex_token (pfile)->type != CPP_EOF)
+      ;
+}
+
+/* Ensure there are no stray tokens at the end of a directive.  */
+static void
+check_eol (cpp_reader *pfile)
+{
+  if (! SEEN_EOL () && _cpp_lex_token (pfile)->type != CPP_EOF)
+    cpp_error (pfile, CPP_DL_PEDWARN, "extra tokens at end of #%s directive",
+	       pfile->directive->name);
+}
+
+/* Ensure there are no stray tokens other than comments at the end of
+   a directive, and gather the comments.  */
+static const cpp_token **
+check_eol_return_comments (cpp_reader *pfile)
+{
+  size_t c;
+  size_t capacity = 8;
+  const cpp_token **buf;
+
+  buf = XNEWVEC (const cpp_token *, capacity);
+  c = 0;
+  if (! SEEN_EOL ())
+    {
+      while (1)
+	{
+	  const cpp_token *tok;
+
+	  tok = _cpp_lex_token (pfile);
+	  if (tok->type == CPP_EOF)
+	    break;
+	  if (tok->type != CPP_COMMENT)
+	    cpp_error (pfile, CPP_DL_PEDWARN,
+		       "extra tokens at end of #%s directive",
+		       pfile->directive->name);
+	  else
+	    {
+	      if (c + 1 >= capacity)
+		{
+		  capacity *= 2;
+		  buf = XRESIZEVEC (const cpp_token *, buf, capacity);
+		}
+	      buf[c] = tok;
+	      ++c;
+	    }
+	}
+    }
+  buf[c] = NULL;
+  return buf;
+}
+
+/* Called when entering a directive, _Pragma or command-line directive.  */
+static void
+start_directive (cpp_reader *pfile)
+{
+  /* Setup in-directive state.  */
+  pfile->state.in_directive = 1;
+  pfile->state.save_comments = 0;
+  pfile->directive_result.type = CPP_PADDING;
+
+  /* Some handlers need the position of the # for diagnostics.  */
+  pfile->directive_line = pfile->line_table->highest_line;
+}
+
+/* Called when leaving a directive, _Pragma or command-line directive.  */
+static void
+end_directive (cpp_reader *pfile, int skip_line)
+{
+  if (pfile->state.in_deferred_pragma)
+    ;
+  else if (CPP_OPTION (pfile, traditional))
+    {
+      /* Revert change of prepare_directive_trad.  */
+      pfile->state.prevent_expansion--;
+
+      if (pfile->directive != &dtable[T_DEFINE])
+	_cpp_remove_overlay (pfile);
+    }
+  /* We don't skip for an assembler #.  */
+  else if (skip_line)
+    {
+      skip_rest_of_line (pfile);
+      if (!pfile->keep_tokens)
+	{
+	  pfile->cur_run = &pfile->base_run;
+	  pfile->cur_token = pfile->base_run.base;
+	}
+    }
+
+  /* Restore state.  */
+  pfile->state.save_comments = ! CPP_OPTION (pfile, discard_comments);
+  pfile->state.in_directive = 0;
+  pfile->state.in_expression = 0;
+  pfile->state.angled_headers = 0;
+  pfile->directive = 0;
+}
+
+/* Prepare to handle the directive in pfile->directive.  */
+static void
+prepare_directive_trad (cpp_reader *pfile)
+{
+  if (pfile->directive != &dtable[T_DEFINE])
+    {
+      bool no_expand = (pfile->directive
+			&& ! (pfile->directive->flags & EXPAND));
+      bool was_skipping = pfile->state.skipping;
+
+      pfile->state.in_expression = (pfile->directive == &dtable[T_IF]
+				    || pfile->directive == &dtable[T_ELIF]);
+      if (pfile->state.in_expression)
+	pfile->state.skipping = false;
+
+      if (no_expand)
+	pfile->state.prevent_expansion++;
+      _cpp_scan_out_logical_line (pfile, NULL);
+      if (no_expand)
+	pfile->state.prevent_expansion--;
+
+      pfile->state.skipping = was_skipping;
+      _cpp_overlay_buffer (pfile, pfile->out.base,
+			   pfile->out.cur - pfile->out.base);
+    }
+
+  /* Stop ISO C from expanding anything.  */
+  pfile->state.prevent_expansion++;
+}
+
+/* Output diagnostics for a directive DIR.  INDENTED is nonzero if
+   the '#' was indented.  */
+static void
+directive_diagnostics (cpp_reader *pfile, const directive *dir, int indented)
+{
+  /* Issue -pedantic or deprecated warnings for extensions.  We let
+     -pedantic take precedence if both are applicable.  */
+  if (! pfile->state.skipping)
+    {
+      if (dir->origin == EXTENSION
+	  && !(dir == &dtable[T_IMPORT] && CPP_OPTION (pfile, objc))
+	  && CPP_PEDANTIC (pfile))
+	cpp_error (pfile, CPP_DL_PEDWARN, "#%s is a GCC extension", dir->name);
+      else if (((dir->flags & DEPRECATED) != 0
+		|| (dir == &dtable[T_IMPORT] && !CPP_OPTION (pfile, objc)))
+	       && CPP_OPTION (pfile, warn_deprecated))
+	cpp_error (pfile, CPP_DL_WARNING, "#%s is a deprecated GCC extension",
+		   dir->name);
+    }
+
+  /* Traditionally, a directive is ignored unless its # is in
+     column 1.  Therefore in code intended to work with K+R
+     compilers, directives added by C89 must have their #
+     indented, and directives present in traditional C must not.
+     This is true even of directives in skipped conditional
+     blocks.  #elif cannot be used at all.  */
+  if (CPP_WTRADITIONAL (pfile))
+    {
+      if (dir == &dtable[T_ELIF])
+	cpp_error (pfile, CPP_DL_WARNING,
+		   "suggest not using #elif in traditional C");
+      else if (indented && dir->origin == KANDR)
+	cpp_error (pfile, CPP_DL_WARNING,
+		   "traditional C ignores #%s with the # indented",
+		   dir->name);
+      else if (!indented && dir->origin != KANDR)
+	cpp_error (pfile, CPP_DL_WARNING,
+		   "suggest hiding #%s from traditional C with an indented #",
+		   dir->name);
+    }
+}
+
+/* Check if we have a known directive.  INDENTED is nonzero if the
+   '#' of the directive was indented.  This function is in this file
+   to save unnecessarily exporting dtable etc. to lex.c.  Returns
+   nonzero if the line of tokens has been handled, zero if we should
+   continue processing the line.  */
+int
+_cpp_handle_directive (cpp_reader *pfile, int indented)
+{
+  const directive *dir = 0;
+  const cpp_token *dname;
+  bool was_parsing_args = pfile->state.parsing_args;
+  bool was_discarding_output = pfile->state.discarding_output;
+  int skip = 1;
+
+  if (was_discarding_output)
+    pfile->state.prevent_expansion = 0;
+
+  if (was_parsing_args)
+    {
+      if (CPP_OPTION (pfile, pedantic))
+	cpp_error (pfile, CPP_DL_PEDWARN,
+	     "embedding a directive within macro arguments is not portable");
+      pfile->state.parsing_args = 0;
+      pfile->state.prevent_expansion = 0;
+    }
+  start_directive (pfile);
+  dname = _cpp_lex_token (pfile);
+
+  if (dname->type == CPP_NAME)
+    {
+      if (dname->val.node->is_directive)
+	dir = &dtable[dname->val.node->directive_index];
+    }
+  /* We do not recognize the # followed by a number extension in
+     assembler code.  */
+  else if (dname->type == CPP_NUMBER && CPP_OPTION (pfile, lang) != CLK_ASM)
+    {
+      dir = &linemarker_dir;
+      if (CPP_PEDANTIC (pfile) && ! CPP_OPTION (pfile, preprocessed)
+	  && ! pfile->state.skipping)
+	cpp_error (pfile, CPP_DL_PEDWARN,
+		   "style of line directive is a GCC extension");
+    }
+
+  if (dir)
+    {
+      /* If we have a directive that is not an opening conditional,
+	 invalidate any control macro.  */
+      if (! (dir->flags & IF_COND))
+	pfile->mi_valid = false;
+
+      /* Kluge alert.  In order to be sure that code like this
+
+	 #define HASH #
+	 HASH define foo bar
+
+	 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.
+	 
+	 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;
+	  dir = 0;
+	}
+      else
+	{
+	  /* In failed conditional groups, all non-conditional
+	     directives are ignored.  Before doing that, whether
+	     skipping or not, we should lex angle-bracketed headers
+	     correctly, and maybe output some diagnostics.  */
+	  pfile->state.angled_headers = dir->flags & INCL;
+	  pfile->state.directive_wants_padding = dir->flags & INCL;
+	  if (! CPP_OPTION (pfile, preprocessed))
+	    directive_diagnostics (pfile, dir, indented);
+	  if (pfile->state.skipping && !(dir->flags & COND))
+	    dir = 0;
+	}
+    }
+  else if (dname->type == CPP_EOF)
+    ;	/* CPP_EOF is the "null directive".  */
+  else
+    {
+      /* An unknown directive.  Don't complain about it in assembly
+	 source: we don't know where the comments are, and # may
+	 introduce assembler pseudo-ops.  Don't complain about invalid
+	 directives in skipped conditional groups (6.10 p4).  */
+      if (CPP_OPTION (pfile, lang) == CLK_ASM)
+	skip = 0;
+      else if (!pfile->state.skipping)
+	cpp_error (pfile, CPP_DL_ERROR, "invalid preprocessing directive #%s",
+		   cpp_token_as_text (pfile, dname));
+    }
+
+  pfile->directive = dir;
+  if (CPP_OPTION (pfile, traditional))
+    prepare_directive_trad (pfile);
+
+  if (dir)
+    pfile->directive->handler (pfile);
+  else if (skip == 0)
+    _cpp_backup_tokens (pfile, 1);
+
+  end_directive (pfile, skip);
+  if (was_parsing_args && !pfile->state.in_deferred_pragma)
+    {
+      /* Restore state when within macro args.  */
+      pfile->state.parsing_args = 2;
+      pfile->state.prevent_expansion = 1;
+    }
+  if (was_discarding_output)
+    pfile->state.prevent_expansion = 1;
+  return skip;
+}
+
+/* Directive handler wrapper used by the command line option
+   processor.  BUF is \n terminated.  */
+static void
+run_directive (cpp_reader *pfile, int dir_no, const char *buf, size_t count)
+{
+  cpp_push_buffer (pfile, (const uchar *) buf, count,
+		   /* from_stage3 */ true);
+  start_directive (pfile);
+
+  /* This is a short-term fix to prevent a leading '#' being
+     interpreted as a directive.  */
+  _cpp_clean_line (pfile);
+
+  pfile->directive = &dtable[dir_no];
+  if (CPP_OPTION (pfile, traditional))
+    prepare_directive_trad (pfile);
+  pfile->directive->handler (pfile);
+  end_directive (pfile, 1);
+  _cpp_pop_buffer (pfile);
+}
+
+/* Checks for validity the macro name in #define, #undef, #ifdef and
+   #ifndef directives.  IS_DEF_OR_UNDEF is true if this call is
+   processing a #define or #undefine directive, and false
+   otherwise.  */
+static cpp_hashnode *
+lex_macro_node (cpp_reader *pfile, bool is_def_or_undef)
+{
+  const cpp_token *token = _cpp_lex_token (pfile);
+
+  /* The token immediately after #define must be an identifier.  That
+     identifier may not be "defined", per C99 6.10.8p4.
+     In C++, it may not be any of the "named operators" either,
+     per C++98 [lex.digraph], [lex.key].
+     Finally, the identifier may not have been poisoned.  (In that case
+     the lexer has issued the error message for us.)  */
+
+  if (token->type == CPP_NAME)
+    {
+      cpp_hashnode *node = token->val.node;
+
+      if (is_def_or_undef && node == pfile->spec_nodes.n_defined)
+	cpp_error (pfile, CPP_DL_ERROR,
+		   "\"defined\" cannot be used as a macro name");
+      else if (! (node->flags & NODE_POISONED))
+	return node;
+    }
+  else if (token->flags & NAMED_OP)
+    cpp_error (pfile, CPP_DL_ERROR,
+       "\"%s\" cannot be used as a macro name as it is an operator in C++",
+	       NODE_NAME (token->val.node));
+  else if (token->type == CPP_EOF)
+    cpp_error (pfile, CPP_DL_ERROR, "no macro name given in #%s directive",
+	       pfile->directive->name);
+  else
+    cpp_error (pfile, CPP_DL_ERROR, "macro names must be identifiers");
+
+  return NULL;
+}
+
+/* Process a #define directive.  Most work is done in macro.c.  */
+static void
+do_define (cpp_reader *pfile)
+{
+  cpp_hashnode *node = lex_macro_node (pfile, true);
+
+  if (node)
+    {
+      /* If we have been requested to expand comments into macros,
+	 then re-enable saving of comments.  */
+      pfile->state.save_comments =
+	! CPP_OPTION (pfile, discard_comments_in_macro_exp);
+
+      if (pfile->cb.before_define)
+	pfile->cb.before_define (pfile);
+
+      if (_cpp_create_definition (pfile, node))
+	if (pfile->cb.define)
+	  pfile->cb.define (pfile, pfile->directive_line, node);
+
+      node->flags &= ~NODE_USED;
+    }
+}
+
+/* Handle #undef.  Mark the identifier NT_VOID in the hash table.  */
+static void
+do_undef (cpp_reader *pfile)
+{
+  cpp_hashnode *node = lex_macro_node (pfile, true);
+
+  if (node)
+    {
+      if (pfile->cb.before_define)
+	pfile->cb.before_define (pfile);
+
+      if (pfile->cb.undef)
+	pfile->cb.undef (pfile, pfile->directive_line, node);
+
+      /* 6.10.3.5 paragraph 2: [#undef] is ignored if the specified
+	 identifier is not currently defined as a macro name.  */
+      if (node->type == NT_MACRO)
+	{
+	  if (node->flags & NODE_WARN)
+	    cpp_error (pfile, CPP_DL_WARNING,
+		       "undefining \"%s\"", NODE_NAME (node));
+
+	  if (CPP_OPTION (pfile, warn_unused_macros))
+	    _cpp_warn_if_unused_macro (pfile, node, NULL);
+
+	  _cpp_free_definition (node);
+	}
+    }
+
+  check_eol (pfile);
+}
+
+/* Undefine a single macro/assertion/whatever.  */
+
+static int
+undefine_macros (cpp_reader *pfile ATTRIBUTE_UNUSED, cpp_hashnode *h,
+		 void *data_p ATTRIBUTE_UNUSED)
+{
+  /* Body of _cpp_free_definition inlined here for speed.
+     Macros and assertions no longer have anything to free.  */
+  h->type = NT_VOID;
+  h->flags &= ~(NODE_POISONED|NODE_BUILTIN|NODE_DISABLED|NODE_USED);
+  return 1;
+}
+
+/* Undefine all macros and assertions.  */
+
+void
+cpp_undef_all (cpp_reader *pfile)
+{
+  cpp_forall_identifiers (pfile, undefine_macros, NULL);
+}
+
+
+/* Helper routine used by parse_include.  Reinterpret the current line
+   as an h-char-sequence (< ... >); we are looking at the first token
+   after the <.  Returns a malloced filename.  */
+static char *
+glue_header_name (cpp_reader *pfile)
+{
+  const cpp_token *token;
+  char *buffer;
+  size_t len, total_len = 0, capacity = 1024;
+
+  /* To avoid lexed tokens overwriting our glued name, we can only
+     allocate from the string pool once we've lexed everything.  */
+  buffer = XNEWVEC (char, capacity);
+  for (;;)
+    {
+      token = get_token_no_padding (pfile);
+
+      if (token->type == CPP_GREATER)
+	break;
+      if (token->type == CPP_EOF)
+	{
+	  cpp_error (pfile, CPP_DL_ERROR, "missing terminating > character");
+	  break;
+	}
+
+      len = cpp_token_len (token) + 2; /* Leading space, terminating \0.  */
+      if (total_len + len > capacity)
+	{
+	  capacity = (capacity + len) * 2;
+	  buffer = XRESIZEVEC (char, buffer, capacity);
+	}
+
+      if (token->flags & PREV_WHITE)
+	buffer[total_len++] = ' ';
+
+      total_len = (cpp_spell_token (pfile, token, (uchar *) &buffer[total_len],
+				    true)
+		   - (uchar *) buffer);
+    }
+
+  buffer[total_len] = '\0';
+  return buffer;
+}
+
+/* Returns the file name of #include, #include_next, #import and
+   #pragma dependency.  The string is malloced and the caller should
+   free it.  Returns NULL on error.  */
+static const char *
+parse_include (cpp_reader *pfile, int *pangle_brackets,
+	       const cpp_token ***buf)
+{
+  char *fname;
+  const cpp_token *header;
+
+  /* Allow macro expansion.  */
+  header = get_token_no_padding (pfile);
+  if (header->type == CPP_STRING || header->type == CPP_HEADER_NAME)
+    {
+      fname = XNEWVEC (char, header->val.str.len - 1);
+      memcpy (fname, header->val.str.text + 1, header->val.str.len - 2);
+      fname[header->val.str.len - 2] = '\0';
+      *pangle_brackets = header->type == CPP_HEADER_NAME;
+    }
+  else if (header->type == CPP_LESS)
+    {
+      fname = glue_header_name (pfile);
+      *pangle_brackets = 1;
+    }
+  else
+    {
+      const unsigned char *dir;
+
+      if (pfile->directive == &dtable[T_PRAGMA])
+	dir = UC"pragma dependency";
+      else
+	dir = pfile->directive->name;
+      cpp_error (pfile, CPP_DL_ERROR, "#%s expects \"FILENAME\" or <FILENAME>",
+		 dir);
+
+      return NULL;
+    }
+
+  if (pfile->directive == &dtable[T_PRAGMA])
+    {
+      /* This pragma allows extra tokens after the file name.  */
+    }
+  else if (buf == NULL || CPP_OPTION (pfile, discard_comments))
+    check_eol (pfile);
+  else
+    {
+      /* If we are not discarding comments, then gather them while
+	 doing the eol check.  */
+      *buf = check_eol_return_comments (pfile);
+    }
+
+  return fname;
+}
+
+/* Handle #include, #include_next and #import.  */
+static void
+do_include_common (cpp_reader *pfile, enum include_type type)
+{
+  const char *fname;
+  int angle_brackets;
+  const cpp_token **buf = NULL;
+
+  /* Re-enable saving of comments if requested, so that the include
+     callback can dump comments which follow #include.  */
+  pfile->state.save_comments = ! CPP_OPTION (pfile, discard_comments);
+
+  fname = parse_include (pfile, &angle_brackets, &buf);
+  if (!fname)
+    {
+      if (buf)
+	XDELETEVEC (buf);
+      return;
+    }
+
+  if (!*fname)
+  {
+    cpp_error (pfile, CPP_DL_ERROR, "empty filename in #%s",
+               pfile->directive->name);
+    XDELETEVEC (fname);
+    if (buf)
+      XDELETEVEC (buf);
+    return;
+  }
+
+  /* Prevent #include recursion.  */
+  if (pfile->line_table->depth >= CPP_STACK_MAX)
+    cpp_error (pfile, CPP_DL_ERROR, "#include nested too deeply");
+  else
+    {
+      /* Get out of macro context, if we are.  */
+      skip_rest_of_line (pfile);
+
+      if (pfile->cb.include)
+	pfile->cb.include (pfile, pfile->directive_line,
+			   pfile->directive->name, fname, angle_brackets,
+			   buf);
+
+      _cpp_stack_include (pfile, fname, angle_brackets, type);
+    }
+
+  XDELETEVEC (fname);
+  if (buf)
+    XDELETEVEC (buf);
+}
+
+static void
+do_include (cpp_reader *pfile)
+{
+  do_include_common (pfile, IT_INCLUDE);
+}
+
+static void
+do_import (cpp_reader *pfile)
+{
+  do_include_common (pfile, IT_IMPORT);
+}
+
+static void
+do_include_next (cpp_reader *pfile)
+{
+  enum include_type type = IT_INCLUDE_NEXT;
+
+  /* If this is the primary source file, warn and use the normal
+     search logic.  */
+  if (cpp_in_primary_file (pfile))
+    {
+      cpp_error (pfile, CPP_DL_WARNING,
+		 "#include_next in primary source file");
+      type = IT_INCLUDE;
+    }
+  do_include_common (pfile, type);
+}
+
+/* Subroutine of do_linemarker.  Read possible flags after file name.
+   LAST is the last flag seen; 0 if this is the first flag. Return the
+   flag if it is valid, 0 at the end of the directive. Otherwise
+   complain.  */
+static unsigned int
+read_flag (cpp_reader *pfile, unsigned int last)
+{
+  const cpp_token *token = _cpp_lex_token (pfile);
+
+  if (token->type == CPP_NUMBER && token->val.str.len == 1)
+    {
+      unsigned int flag = token->val.str.text[0] - '0';
+
+      if (flag > last && flag <= 4
+	  && (flag != 4 || last == 3)
+	  && (flag != 2 || last == 0))
+	return flag;
+    }
+
+  if (token->type != CPP_EOF)
+    cpp_error (pfile, CPP_DL_ERROR, "invalid flag \"%s\" in line directive",
+	       cpp_token_as_text (pfile, token));
+  return 0;
+}
+
+/* Subroutine of do_line and do_linemarker.  Convert a number in STR,
+   of length LEN, to binary; store it in NUMP, and return false if the
+   number was well-formed, true if not. WRAPPED is set to true if the
+   number did not fit into 'unsigned long'.  */
+static bool
+strtolinenum (const uchar *str, size_t len, linenum_type *nump, bool *wrapped)
+{
+  linenum_type reg = 0;
+  linenum_type reg_prev = 0;
+
+  uchar c;
+  *wrapped = false;
+  while (len--)
+    {
+      c = *str++;
+      if (!ISDIGIT (c))
+	return true;
+      reg *= 10;
+      reg += c - '0';
+      if (reg < reg_prev) 
+	*wrapped = true;
+      reg_prev = reg;
+    }
+  *nump = reg;
+  return false;
+}
+
+/* Interpret #line command.
+   Note that the filename string (if any) is a true string constant
+   (escapes are interpreted), unlike in #line.  */
+static void
+do_line (cpp_reader *pfile)
+{
+  const struct line_maps *line_table = pfile->line_table;
+  const struct line_map *map = &line_table->maps[line_table->used - 1];
+
+  /* skip_rest_of_line() may cause line table to be realloc()ed so note down
+     sysp right now.  */
+
+  unsigned char map_sysp = map->sysp;
+  const cpp_token *token;
+  const char *new_file = map->to_file;
+  linenum_type new_lineno;
+
+  /* C99 raised the minimum limit on #line numbers.  */
+  linenum_type cap = CPP_OPTION (pfile, c99) ? 2147483647 : 32767;
+  bool wrapped;
+
+  /* #line commands expand macros.  */
+  token = cpp_get_token (pfile);
+  if (token->type != CPP_NUMBER
+      || strtolinenum (token->val.str.text, token->val.str.len,
+		       &new_lineno, &wrapped))
+    {
+      if (token->type == CPP_EOF)
+	cpp_error (pfile, CPP_DL_ERROR, "unexpected end of file after #line");
+      else
+	cpp_error (pfile, CPP_DL_ERROR,
+		   "\"%s\" after #line is not a positive integer",
+		   cpp_token_as_text (pfile, token));
+      return;
+    }
+
+  if (CPP_PEDANTIC (pfile) && (new_lineno == 0 || new_lineno > cap || wrapped))
+    cpp_error (pfile, CPP_DL_PEDWARN, "line number out of range");
+  else if (wrapped)
+    cpp_error (pfile, CPP_DL_WARNING, "line number out of range");
+
+  token = cpp_get_token (pfile);
+  if (token->type == CPP_STRING)
+    {
+      cpp_string s = { 0, 0 };
+      if (cpp_interpret_string_notranslate (pfile, &token->val.str, 1,
+					    &s, false))
+	new_file = (const char *)s.text;
+      check_eol (pfile);
+    }
+  else if (token->type != CPP_EOF)
+    {
+      cpp_error (pfile, CPP_DL_ERROR, "\"%s\" is not a valid filename",
+		 cpp_token_as_text (pfile, token));
+      return;
+    }
+
+  skip_rest_of_line (pfile);
+  _cpp_do_file_change (pfile, LC_RENAME, new_file, new_lineno,
+		       map_sysp);
+}
+
+/* Interpret the # 44 "file" [flags] notation, which has slightly
+   different syntax and semantics from #line:  Flags are allowed,
+   and we never complain about the line number being too big.  */
+static void
+do_linemarker (cpp_reader *pfile)
+{
+  const struct line_maps *line_table = pfile->line_table;
+  const struct line_map *map = &line_table->maps[line_table->used - 1];
+  const cpp_token *token;
+  const char *new_file = map->to_file;
+  linenum_type new_lineno;
+  unsigned int new_sysp = map->sysp;
+  enum lc_reason reason = LC_RENAME;
+  int flag;
+  bool wrapped;
+
+  /* Back up so we can get the number again.  Putting this in
+     _cpp_handle_directive risks two calls to _cpp_backup_tokens in
+     some circumstances, which can segfault.  */
+  _cpp_backup_tokens (pfile, 1);
+
+  /* #line commands expand macros.  */
+  token = cpp_get_token (pfile);
+  if (token->type != CPP_NUMBER
+      || strtolinenum (token->val.str.text, token->val.str.len,
+		       &new_lineno, &wrapped))
+    {
+      /* Unlike #line, there does not seem to be a way to get an EOF
+	 here.  So, it should be safe to always spell the token.  */
+      cpp_error (pfile, CPP_DL_ERROR,
+		 "\"%s\" after # is not a positive integer",
+		 cpp_token_as_text (pfile, token));
+      return;
+    }
+
+  token = cpp_get_token (pfile);
+  if (token->type == CPP_STRING)
+    {
+      cpp_string s = { 0, 0 };
+      if (cpp_interpret_string_notranslate (pfile, &token->val.str,
+					    1, &s, false))
+	new_file = (const char *)s.text;
+
+      new_sysp = 0;
+      flag = read_flag (pfile, 0);
+      if (flag == 1)
+	{
+	  reason = LC_ENTER;
+	  /* Fake an include for cpp_included ().  */
+	  _cpp_fake_include (pfile, new_file);
+	  flag = read_flag (pfile, flag);
+	}
+      else if (flag == 2)
+	{
+	  reason = LC_LEAVE;
+	  flag = read_flag (pfile, flag);
+	}
+      if (flag == 3)
+	{
+	  new_sysp = 1;
+	  flag = read_flag (pfile, flag);
+	  if (flag == 4)
+	    new_sysp = 2;
+	}
+      pfile->buffer->sysp = new_sysp;
+
+      check_eol (pfile);
+    }
+  else if (token->type != CPP_EOF)
+    {
+      cpp_error (pfile, CPP_DL_ERROR, "\"%s\" is not a valid filename",
+		 cpp_token_as_text (pfile, token));
+      return;
+    }
+
+  skip_rest_of_line (pfile);
+  _cpp_do_file_change (pfile, reason, new_file, new_lineno, new_sysp);
+}
+
+/* Arrange the file_change callback.  pfile->line has changed to
+   FILE_LINE of TO_FILE, for reason REASON.  SYSP is 1 for a system
+   header, 2 for a system header that needs to be extern "C" protected,
+   and zero otherwise.  */
+void
+_cpp_do_file_change (cpp_reader *pfile, enum lc_reason reason,
+		     const char *to_file, linenum_type file_line,
+		     unsigned int sysp)
+{
+  const struct line_map *map = linemap_add (pfile->line_table, reason, sysp,
+					    to_file, file_line);
+  if (map != NULL)
+    linemap_line_start (pfile->line_table, map->to_line, 127);
+
+  if (pfile->cb.file_change)
+    pfile->cb.file_change (pfile, map);
+}
+
+/* Report a warning or error detected by the program we are
+   processing.  Use the directive's tokens in the error message.  */
+static void
+do_diagnostic (cpp_reader *pfile, int code, int print_dir)
+{
+  const unsigned char *dir_name;
+  unsigned char *line;
+  source_location src_loc = pfile->cur_token[-1].src_loc;
+
+  if (print_dir)
+    dir_name = pfile->directive->name;
+  else
+    dir_name = NULL;
+  pfile->state.prevent_expansion++;
+  line = cpp_output_line_to_string (pfile, dir_name);
+  pfile->state.prevent_expansion--;
+
+  cpp_error_with_line (pfile, code, src_loc, 0, "%s", line);
+  free (line);
+}
+
+static void
+do_error (cpp_reader *pfile)
+{
+  do_diagnostic (pfile, CPP_DL_ERROR, 1);
+}
+
+static void
+do_warning (cpp_reader *pfile)
+{
+  /* We want #warning diagnostics to be emitted in system headers too.  */
+  do_diagnostic (pfile, CPP_DL_WARNING_SYSHDR, 1);
+}
+
+/* Report program identification.  */
+static void
+do_ident (cpp_reader *pfile)
+{
+  const cpp_token *str = cpp_get_token (pfile);
+
+  if (str->type != CPP_STRING)
+    cpp_error (pfile, CPP_DL_ERROR, "invalid #%s directive",
+	       pfile->directive->name);
+  else if (pfile->cb.ident)
+    pfile->cb.ident (pfile, pfile->directive_line, &str->val.str);
+
+  check_eol (pfile);
+}
+
+/* Lookup a PRAGMA name in a singly-linked CHAIN.  Returns the
+   matching entry, or NULL if none is found.  The returned entry could
+   be the start of a namespace chain, or a pragma.  */
+static struct pragma_entry *
+lookup_pragma_entry (struct pragma_entry *chain, const cpp_hashnode *pragma)
+{
+  while (chain && chain->pragma != pragma)
+    chain = chain->next;
+
+  return chain;
+}
+
+/* Create and insert a blank pragma entry at the beginning of a
+   singly-linked CHAIN.  */
+static struct pragma_entry *
+new_pragma_entry (cpp_reader *pfile, struct pragma_entry **chain)
+{
+  struct pragma_entry *new_entry;
+
+  new_entry = (struct pragma_entry *)
+    _cpp_aligned_alloc (pfile, sizeof (struct pragma_entry));
+
+  memset (new_entry, 0, sizeof (struct pragma_entry));
+  new_entry->next = *chain;
+
+  *chain = new_entry;
+  return new_entry;
+}
+
+/* Register a pragma NAME in namespace SPACE.  If SPACE is null, it
+   goes in the global namespace.  */
+static struct pragma_entry *
+register_pragma_1 (cpp_reader *pfile, const char *space, const char *name,
+		   bool allow_name_expansion)
+{
+  struct pragma_entry **chain = &pfile->pragmas;
+  struct pragma_entry *entry;
+  const cpp_hashnode *node;
+
+  if (space)
+    {
+      node = cpp_lookup (pfile, UC space, strlen (space));
+      entry = lookup_pragma_entry (*chain, node);
+      if (!entry)
+	{
+	  entry = new_pragma_entry (pfile, chain);
+	  entry->pragma = node;
+	  entry->is_nspace = true;
+	  entry->allow_expansion = allow_name_expansion;
+	}
+      else if (!entry->is_nspace)
+	goto clash;
+      else if (entry->allow_expansion != allow_name_expansion)
+	{
+	  cpp_error (pfile, CPP_DL_ICE,
+		     "registering pragmas in namespace \"%s\" with mismatched "
+		     "name expansion", space);
+	  return NULL;
+	}
+      chain = &entry->u.space;
+    }
+  else if (allow_name_expansion)
+    {
+      cpp_error (pfile, CPP_DL_ICE,
+		 "registering pragma \"%s\" with name expansion "
+		 "and no namespace", name);
+      return NULL;
+    }
+
+  /* Check for duplicates.  */
+  node = cpp_lookup (pfile, UC name, strlen (name));
+  entry = lookup_pragma_entry (*chain, node);
+  if (entry == NULL)
+    {
+      entry = new_pragma_entry (pfile, chain);
+      entry->pragma = node;
+      return entry;
+    }
+
+  if (entry->is_nspace)
+    clash:
+    cpp_error (pfile, CPP_DL_ICE,
+	       "registering \"%s\" as both a pragma and a pragma namespace",
+	       NODE_NAME (node));
+  else if (space)
+    cpp_error (pfile, CPP_DL_ICE, "#pragma %s %s is already registered",
+	       space, name);
+  else
+    cpp_error (pfile, CPP_DL_ICE, "#pragma %s is already registered", name);
+
+  return NULL;
+}
+
+/* Register a cpplib internal pragma SPACE NAME with HANDLER.  */
+static void
+register_pragma_internal (cpp_reader *pfile, const char *space,
+			  const char *name, pragma_cb handler)
+{
+  struct pragma_entry *entry;
+
+  entry = register_pragma_1 (pfile, space, name, false);
+  entry->is_internal = true;
+  entry->u.handler = handler;
+}
+
+/* Register a pragma NAME in namespace SPACE.  If SPACE is null, it
+   goes in the global namespace.  HANDLER is the handler it will call,
+   which must be non-NULL.  If ALLOW_EXPANSION is set, allow macro
+   expansion while parsing pragma NAME.  This function is exported
+   from libcpp. */
+void
+cpp_register_pragma (cpp_reader *pfile, const char *space, const char *name,
+		     pragma_cb handler, bool allow_expansion)
+{
+  struct pragma_entry *entry;
+
+  if (!handler)
+    {
+      cpp_error (pfile, CPP_DL_ICE, "registering pragma with NULL handler");
+      return;
+    }
+
+  entry = register_pragma_1 (pfile, space, name, false);
+  if (entry)
+    {
+      entry->allow_expansion = allow_expansion;
+      entry->u.handler = handler;
+    }
+}
+
+/* Similarly, but create mark the pragma for deferred processing.
+   When found, a CPP_PRAGMA token will be insertted into the stream
+   with IDENT in the token->u.pragma slot.  */
+void
+cpp_register_deferred_pragma (cpp_reader *pfile, const char *space,
+			      const char *name, unsigned int ident,
+			      bool allow_expansion, bool allow_name_expansion)
+{
+  struct pragma_entry *entry;
+
+  entry = register_pragma_1 (pfile, space, name, allow_name_expansion);
+  if (entry)
+    {
+      entry->is_deferred = true;
+      entry->allow_expansion = allow_expansion;
+      entry->u.ident = ident;
+    }
+}  
+
+/* Register the pragmas the preprocessor itself handles.  */
+void
+_cpp_init_internal_pragmas (cpp_reader *pfile)
+{
+  /* Pragmas in the global namespace.  */
+  register_pragma_internal (pfile, 0, "once", do_pragma_once);
+
+  /* New GCC-specific pragmas should be put in the GCC namespace.  */
+  register_pragma_internal (pfile, "GCC", "poison", do_pragma_poison);
+  register_pragma_internal (pfile, "GCC", "system_header",
+			    do_pragma_system_header);
+  register_pragma_internal (pfile, "GCC", "dependency", do_pragma_dependency);
+}
+
+/* Return the number of registered pragmas in PE.  */
+
+static int
+count_registered_pragmas (struct pragma_entry *pe)
+{
+  int ct = 0;
+  for (; pe != NULL; pe = pe->next)
+    {
+      if (pe->is_nspace)
+	ct += count_registered_pragmas (pe->u.space);
+      ct++;
+    }
+  return ct;
+}
+
+/* Save into SD the names of the registered pragmas referenced by PE,
+   and return a pointer to the next free space in SD.  */
+
+static char **
+save_registered_pragmas (struct pragma_entry *pe, char **sd)
+{
+  for (; pe != NULL; pe = pe->next)
+    {
+      if (pe->is_nspace)
+	sd = save_registered_pragmas (pe->u.space, sd);
+      *sd++ = (char *) xmemdup (HT_STR (&pe->pragma->ident),
+                                HT_LEN (&pe->pragma->ident),
+                                HT_LEN (&pe->pragma->ident) + 1);
+    }
+  return sd;
+}
+
+/* Return a newly-allocated array which saves the names of the
+   registered pragmas.  */
+
+char **
+_cpp_save_pragma_names (cpp_reader *pfile)
+{
+  int ct = count_registered_pragmas (pfile->pragmas);
+  char **result = XNEWVEC (char *, ct);
+  (void) save_registered_pragmas (pfile->pragmas, result);
+  return result;
+}
+
+/* Restore from SD the names of the registered pragmas referenced by PE,
+   and return a pointer to the next unused name in SD.  */
+
+static char **
+restore_registered_pragmas (cpp_reader *pfile, struct pragma_entry *pe,
+			    char **sd)
+{
+  for (; pe != NULL; pe = pe->next)
+    {
+      if (pe->is_nspace)
+	sd = restore_registered_pragmas (pfile, pe->u.space, sd);
+      pe->pragma = cpp_lookup (pfile, UC *sd, strlen (*sd));
+      free (*sd);
+      sd++;
+    }
+  return sd;
+}
+
+/* Restore the names of the registered pragmas from SAVED.  */
+
+void
+_cpp_restore_pragma_names (cpp_reader *pfile, char **saved)
+{
+  (void) restore_registered_pragmas (pfile, pfile->pragmas, saved);
+  free (saved);
+}
+
+/* Pragmata handling.  We handle some, and pass the rest on to the
+   front end.  C99 defines three pragmas and says that no macro
+   expansion is to be performed on them; whether or not macro
+   expansion happens for other pragmas is implementation defined.
+   This implementation allows for a mix of both, since GCC did not
+   traditionally macro expand its (few) pragmas, whereas OpenMP
+   specifies that macro expansion should happen.  */
+static void
+do_pragma (cpp_reader *pfile)
+{
+  const struct pragma_entry *p = NULL;
+  const cpp_token *token, *pragma_token = pfile->cur_token;
+  cpp_token ns_token;
+  unsigned int count = 1;
+
+  pfile->state.prevent_expansion++;
+
+  token = cpp_get_token (pfile);
+  ns_token = *token;
+  if (token->type == CPP_NAME)
+    {
+      p = lookup_pragma_entry (pfile->pragmas, token->val.node);
+      if (p && p->is_nspace)
+	{
+	  bool allow_name_expansion = p->allow_expansion;
+	  if (allow_name_expansion)
+	    pfile->state.prevent_expansion--;
+	  token = cpp_get_token (pfile);
+	  if (token->type == CPP_NAME)
+	    p = lookup_pragma_entry (p->u.space, token->val.node);
+	  else
+	    p = NULL;
+	  if (allow_name_expansion)
+	    pfile->state.prevent_expansion++;
+	  count = 2;
+	}
+    }
+
+  if (p)
+    {
+      if (p->is_deferred)
+	{
+	  pfile->directive_result.src_loc = pragma_token->src_loc;
+	  pfile->directive_result.type = CPP_PRAGMA;
+	  pfile->directive_result.flags = pragma_token->flags;
+	  pfile->directive_result.val.pragma = p->u.ident;
+	  pfile->state.in_deferred_pragma = true;
+	  pfile->state.pragma_allow_expansion = p->allow_expansion;
+	  if (!p->allow_expansion)
+	    pfile->state.prevent_expansion++;
+	}
+      else
+	{
+	  /* Since the handler below doesn't get the line number, that
+	     it might need for diagnostics, make sure it has the right
+	     numbers in place.  */
+	  if (pfile->cb.line_change)
+	    (*pfile->cb.line_change) (pfile, pragma_token, false);
+	  if (p->allow_expansion)
+	    pfile->state.prevent_expansion--;
+	  (*p->u.handler) (pfile);
+	  if (p->allow_expansion)
+	    pfile->state.prevent_expansion++;
+	}
+    }
+  else if (pfile->cb.def_pragma)
+    {
+      if (count == 1 || pfile->context->prev == NULL)
+	_cpp_backup_tokens (pfile, count);
+      else
+	{
+	  /* Invalid name comes from macro expansion, _cpp_backup_tokens
+	     won't allow backing 2 tokens.  */
+	  /* ??? The token buffer is leaked.  Perhaps if def_pragma hook
+	     reads both tokens, we could perhaps free it, but if it doesn't,
+	     we don't know the exact lifespan.  */
+	  cpp_token *toks = XNEWVEC (cpp_token, 2);
+	  toks[0] = ns_token;
+	  toks[0].flags |= NO_EXPAND;
+	  toks[1] = *token;
+	  toks[1].flags |= NO_EXPAND;
+	  _cpp_push_token_context (pfile, NULL, toks, 2);
+	}
+      pfile->cb.def_pragma (pfile, pfile->directive_line);
+    }
+
+  pfile->state.prevent_expansion--;
+}
+
+/* Handle #pragma once.  */
+static void
+do_pragma_once (cpp_reader *pfile)
+{
+  if (cpp_in_primary_file (pfile))
+    cpp_error (pfile, CPP_DL_WARNING, "#pragma once in main file");
+
+  check_eol (pfile);
+  _cpp_mark_file_once_only (pfile, pfile->buffer->file);
+}
+
+/* Handle #pragma GCC poison, to poison one or more identifiers so
+   that the lexer produces a hard error for each subsequent usage.  */
+static void
+do_pragma_poison (cpp_reader *pfile)
+{
+  const cpp_token *tok;
+  cpp_hashnode *hp;
+
+  pfile->state.poisoned_ok = 1;
+  for (;;)
+    {
+      tok = _cpp_lex_token (pfile);
+      if (tok->type == CPP_EOF)
+	break;
+      if (tok->type != CPP_NAME)
+	{
+	  cpp_error (pfile, CPP_DL_ERROR,
+		     "invalid #pragma GCC poison directive");
+	  break;
+	}
+
+      hp = tok->val.node;
+      if (hp->flags & NODE_POISONED)
+	continue;
+
+      if (hp->type == NT_MACRO)
+	cpp_error (pfile, CPP_DL_WARNING, "poisoning existing macro \"%s\"",
+		   NODE_NAME (hp));
+      _cpp_free_definition (hp);
+      hp->flags |= NODE_POISONED | NODE_DIAGNOSTIC;
+    }
+  pfile->state.poisoned_ok = 0;
+}
+
+/* Mark the current header as a system header.  This will suppress
+   some categories of warnings (notably those from -pedantic).  It is
+   intended for use in system libraries that cannot be implemented in
+   conforming C, but cannot be certain that their headers appear in a
+   system include directory.  To prevent abuse, it is rejected in the
+   primary source file.  */
+static void
+do_pragma_system_header (cpp_reader *pfile)
+{
+  if (cpp_in_primary_file (pfile))
+    cpp_error (pfile, CPP_DL_WARNING,
+	       "#pragma system_header ignored outside include file");
+  else
+    {
+      check_eol (pfile);
+      skip_rest_of_line (pfile);
+      cpp_make_system_header (pfile, 1, 0);
+    }
+}
+
+/* Check the modified date of the current include file against a specified
+   file. Issue a diagnostic, if the specified file is newer. We use this to
+   determine if a fixed header should be refixed.  */
+static void
+do_pragma_dependency (cpp_reader *pfile)
+{
+  const char *fname;
+  int angle_brackets, ordering;
+
+  fname = parse_include (pfile, &angle_brackets, NULL);
+  if (!fname)
+    return;
+
+  ordering = _cpp_compare_file_date (pfile, fname, angle_brackets);
+  if (ordering < 0)
+    cpp_error (pfile, CPP_DL_WARNING, "cannot find source file %s", fname);
+  else if (ordering > 0)
+    {
+      cpp_error (pfile, CPP_DL_WARNING,
+		 "current file is older than %s", fname);
+      if (cpp_get_token (pfile)->type != CPP_EOF)
+	{
+	  _cpp_backup_tokens (pfile, 1);
+	  do_diagnostic (pfile, CPP_DL_WARNING, 0);
+	}
+    }
+
+  free ((void *) fname);
+}
+
+/* Get a token but skip padding.  */
+static const cpp_token *
+get_token_no_padding (cpp_reader *pfile)
+{
+  for (;;)
+    {
+      const cpp_token *result = cpp_get_token (pfile);
+      if (result->type != CPP_PADDING)
+	return result;
+    }
+}
+
+/* Check syntax is "(string-literal)".  Returns the string on success,
+   or NULL on failure.  */
+static const cpp_token *
+get__Pragma_string (cpp_reader *pfile)
+{
+  const cpp_token *string;
+  const cpp_token *paren;
+
+  paren = get_token_no_padding (pfile);
+  if (paren->type == CPP_EOF)
+    _cpp_backup_tokens (pfile, 1);
+  if (paren->type != CPP_OPEN_PAREN)
+    return NULL;
+
+  string = get_token_no_padding (pfile);
+  if (string->type == CPP_EOF)
+    _cpp_backup_tokens (pfile, 1);
+  if (string->type != CPP_STRING && string->type != CPP_WSTRING
+      && string->type != CPP_STRING32 && string->type != CPP_STRING16)
+    return NULL;
+
+  paren = get_token_no_padding (pfile);
+  if (paren->type == CPP_EOF)
+    _cpp_backup_tokens (pfile, 1);
+  if (paren->type != CPP_CLOSE_PAREN)
+    return NULL;
+
+  return string;
+}
+
+/* Destringize IN into a temporary buffer, by removing the first \ of
+   \" and \\ sequences, and process the result as a #pragma directive.  */
+static void
+destringize_and_run (cpp_reader *pfile, const cpp_string *in)
+{
+  const unsigned char *src, *limit;
+  char *dest, *result;
+  cpp_context *saved_context;
+  cpp_token *saved_cur_token;
+  tokenrun *saved_cur_run;
+  cpp_token *toks;
+  int count;
+  const struct directive *save_directive;
+
+  dest = result = (char *) alloca (in->len - 1);
+  src = in->text + 1 + (in->text[0] == 'L');
+  limit = in->text + in->len - 1;
+  while (src < limit)
+    {
+      /* We know there is a character following the backslash.  */
+      if (*src == '\\' && (src[1] == '\\' || src[1] == '"'))
+	src++;
+      *dest++ = *src++;
+    }
+  *dest = '\n';
+
+  /* Ugh; an awful kludge.  We are really not set up to be lexing
+     tokens when in the middle of a macro expansion.  Use a new
+     context to force cpp_get_token to lex, and so skip_rest_of_line
+     doesn't go beyond the end of the text.  Also, remember the
+     current lexing position so we can return to it later.
+
+     Something like line-at-a-time lexing should remove the need for
+     this.  */
+  saved_context = pfile->context;
+  saved_cur_token = pfile->cur_token;
+  saved_cur_run = pfile->cur_run;
+
+  pfile->context = XNEW (cpp_context);
+  pfile->context->macro = 0;
+  pfile->context->prev = 0;
+  pfile->context->next = 0;
+
+  /* Inline run_directive, since we need to delay the _cpp_pop_buffer
+     until we've read all of the tokens that we want.  */
+  cpp_push_buffer (pfile, (const uchar *) result, dest - result,
+		   /* from_stage3 */ true);
+  /* ??? Antique Disgusting Hack.  What does this do?  */
+  if (pfile->buffer->prev)
+    pfile->buffer->file = pfile->buffer->prev->file;
+
+  start_directive (pfile);
+  _cpp_clean_line (pfile);
+  save_directive = pfile->directive;
+  pfile->directive = &dtable[T_PRAGMA];
+  do_pragma (pfile);
+  end_directive (pfile, 1);
+  pfile->directive = save_directive;
+
+  /* We always insert at least one token, the directive result.  It'll
+     either be a CPP_PADDING or a CPP_PRAGMA.  In the later case, we 
+     need to insert *all* of the tokens, including the CPP_PRAGMA_EOL.  */
+
+  /* If we're not handling the pragma internally, read all of the tokens from
+     the string buffer now, while the string buffer is still installed.  */
+  /* ??? Note that the token buffer allocated here is leaked.  It's not clear
+     to me what the true lifespan of the tokens are.  It would appear that
+     the lifespan is the entire parse of the main input stream, in which case
+     this may not be wrong.  */
+  if (pfile->directive_result.type == CPP_PRAGMA)
+    {
+      int maxcount;
+
+      count = 1;
+      maxcount = 50;
+      toks = XNEWVEC (cpp_token, maxcount);
+      toks[0] = pfile->directive_result;
+
+      do
+	{
+	  if (count == maxcount)
+	    {
+	      maxcount = maxcount * 3 / 2;
+	      toks = XRESIZEVEC (cpp_token, toks, maxcount);
+	    }
+	  toks[count] = *cpp_get_token (pfile);
+	  /* Macros have been already expanded by cpp_get_token
+	     if the pragma allowed expansion.  */
+	  toks[count++].flags |= NO_EXPAND;
+	}
+      while (toks[count-1].type != CPP_PRAGMA_EOL);
+    }
+  else
+    {
+      count = 1;
+      toks = XNEW (cpp_token);
+      toks[0] = pfile->directive_result;
+
+      /* If we handled the entire pragma internally, make sure we get the
+	 line number correct for the next token.  */
+      if (pfile->cb.line_change)
+	pfile->cb.line_change (pfile, pfile->cur_token, false);
+    }
+
+  /* Finish inlining run_directive.  */
+  pfile->buffer->file = NULL;
+  _cpp_pop_buffer (pfile);
+
+  /* Reset the old macro state before ...  */
+  XDELETE (pfile->context);
+  pfile->context = saved_context;
+  pfile->cur_token = saved_cur_token;
+  pfile->cur_run = saved_cur_run;
+
+  /* ... inserting the new tokens we collected.  */
+  _cpp_push_token_context (pfile, NULL, toks, count);
+}
+
+/* Handle the _Pragma operator.  Return 0 on error, 1 if ok.  */
+int
+_cpp_do__Pragma (cpp_reader *pfile)
+{
+  const cpp_token *string = get__Pragma_string (pfile);
+  pfile->directive_result.type = CPP_PADDING;
+
+  if (string)
+    {
+      destringize_and_run (pfile, &string->val.str);
+      return 1;
+    }
+  cpp_error (pfile, CPP_DL_ERROR,
+	     "_Pragma takes a parenthesized string literal");
+  return 0;
+}
+
+/* Handle #ifdef.  */
+static void
+do_ifdef (cpp_reader *pfile)
+{
+  int skip = 1;
+
+  if (! pfile->state.skipping)
+    {
+      cpp_hashnode *node = lex_macro_node (pfile, false);
+
+      if (node)
+	{
+	  skip = node->type != NT_MACRO;
+	  _cpp_mark_macro_used (node);
+	  if (!(node->flags & NODE_USED))
+	    {
+	      node->flags |= NODE_USED;
+	      if (node->type == NT_MACRO)
+		{
+		  if (pfile->cb.used_define)
+		    pfile->cb.used_define (pfile, pfile->directive_line, node);
+		}
+	      else
+		{
+		  if (pfile->cb.used_undef)
+		    pfile->cb.used_undef (pfile, pfile->directive_line, node);
+		}
+	    }
+	  check_eol (pfile);
+	}
+    }
+
+  push_conditional (pfile, skip, T_IFDEF, 0);
+}
+
+/* Handle #ifndef.  */
+static void
+do_ifndef (cpp_reader *pfile)
+{
+  int skip = 1;
+  cpp_hashnode *node = 0;
+
+  if (! pfile->state.skipping)
+    {
+      node = lex_macro_node (pfile, false);
+
+      if (node)
+	{
+	  skip = node->type == NT_MACRO;
+	  _cpp_mark_macro_used (node);
+	  if (!(node->flags & NODE_USED))
+	    {
+	      node->flags |= NODE_USED;
+	      if (node->type == NT_MACRO)
+		{
+		  if (pfile->cb.used_define)
+		    pfile->cb.used_define (pfile, pfile->directive_line, node);
+		}
+	      else
+		{
+		  if (pfile->cb.used_undef)
+		    pfile->cb.used_undef (pfile, pfile->directive_line, node);
+		}
+	    }
+	  check_eol (pfile);
+	}
+    }
+
+  push_conditional (pfile, skip, T_IFNDEF, node);
+}
+
+/* _cpp_parse_expr puts a macro in a "#if !defined ()" expression in
+   pfile->mi_ind_cmacro so we can handle multiple-include
+   optimizations.  If macro expansion occurs in the expression, we
+   cannot treat it as a controlling conditional, since the expansion
+   could change in the future.  That is handled by cpp_get_token.  */
+static void
+do_if (cpp_reader *pfile)
+{
+  int skip = 1;
+
+  if (! pfile->state.skipping)
+    skip = _cpp_parse_expr (pfile, true) == false;
+
+  push_conditional (pfile, skip, T_IF, pfile->mi_ind_cmacro);
+}
+
+/* Flip skipping state if appropriate and continue without changing
+   if_stack; this is so that the error message for missing #endif's
+   etc. will point to the original #if.  */
+static void
+do_else (cpp_reader *pfile)
+{
+  cpp_buffer *buffer = pfile->buffer;
+  struct if_stack *ifs = buffer->if_stack;
+
+  if (ifs == NULL)
+    cpp_error (pfile, CPP_DL_ERROR, "#else without #if");
+  else
+    {
+      if (ifs->type == T_ELSE)
+	{
+	  cpp_error (pfile, CPP_DL_ERROR, "#else after #else");
+	  cpp_error_with_line (pfile, CPP_DL_ERROR, ifs->line, 0,
+			       "the conditional began here");
+	}
+      ifs->type = T_ELSE;
+
+      /* Skip any future (erroneous) #elses or #elifs.  */
+      pfile->state.skipping = ifs->skip_elses;
+      ifs->skip_elses = true;
+
+      /* Invalidate any controlling macro.  */
+      ifs->mi_cmacro = 0;
+
+      /* Only check EOL if was not originally skipping.  */
+      if (!ifs->was_skipping && CPP_OPTION (pfile, warn_endif_labels))
+	check_eol (pfile);
+    }
+}
+
+/* Handle a #elif directive by not changing if_stack either.  See the
+   comment above do_else.  */
+static void
+do_elif (cpp_reader *pfile)
+{
+  cpp_buffer *buffer = pfile->buffer;
+  struct if_stack *ifs = buffer->if_stack;
+
+  if (ifs == NULL)
+    cpp_error (pfile, CPP_DL_ERROR, "#elif without #if");
+  else
+    {
+      if (ifs->type == T_ELSE)
+	{
+	  cpp_error (pfile, CPP_DL_ERROR, "#elif after #else");
+	  cpp_error_with_line (pfile, CPP_DL_ERROR, ifs->line, 0,
+			       "the conditional began here");
+	}
+      ifs->type = T_ELIF;
+
+      if (! ifs->was_skipping)
+	{
+	  bool value;
+	  /* The standard mandates that the expression be parsed even
+	     if we are skipping elses at this point -- the lexical
+	     restrictions on #elif only apply to skipped groups, but
+	     this group is not being skipped.  Temporarily set
+	     skipping to false to get lexer warnings.  */
+	  pfile->state.skipping = 0;
+	  value = _cpp_parse_expr (pfile, false);
+	  if (ifs->skip_elses)
+	    pfile->state.skipping = 1;
+	  else
+	    {
+	      pfile->state.skipping = ! value;
+	      ifs->skip_elses = value;
+	    }
+	}
+
+      /* Invalidate any controlling macro.  */
+      ifs->mi_cmacro = 0;
+    }
+}
+
+/* #endif pops the if stack and resets pfile->state.skipping.  */
+static void
+do_endif (cpp_reader *pfile)
+{
+  cpp_buffer *buffer = pfile->buffer;
+  struct if_stack *ifs = buffer->if_stack;
+
+  if (ifs == NULL)
+    cpp_error (pfile, CPP_DL_ERROR, "#endif without #if");
+  else
+    {
+      /* Only check EOL if was not originally skipping.  */
+      if (!ifs->was_skipping && CPP_OPTION (pfile, warn_endif_labels))
+	check_eol (pfile);
+
+      /* If potential control macro, we go back outside again.  */
+      if (ifs->next == 0 && ifs->mi_cmacro)
+	{
+	  pfile->mi_valid = true;
+	  pfile->mi_cmacro = ifs->mi_cmacro;
+	}
+
+      buffer->if_stack = ifs->next;
+      pfile->state.skipping = ifs->was_skipping;
+      obstack_free (&pfile->buffer_ob, ifs);
+    }
+}
+
+/* Push an if_stack entry for a preprocessor conditional, and set
+   pfile->state.skipping to SKIP.  If TYPE indicates the conditional
+   is #if or #ifndef, CMACRO is a potentially controlling macro, and
+   we need to check here that we are at the top of the file.  */
+static void
+push_conditional (cpp_reader *pfile, int skip, int type,
+		  const cpp_hashnode *cmacro)
+{
+  struct if_stack *ifs;
+  cpp_buffer *buffer = pfile->buffer;
+
+  ifs = XOBNEW (&pfile->buffer_ob, struct if_stack);
+  ifs->line = pfile->directive_line;
+  ifs->next = buffer->if_stack;
+  ifs->skip_elses = pfile->state.skipping || !skip;
+  ifs->was_skipping = pfile->state.skipping;
+  ifs->type = type;
+  /* This condition is effectively a test for top-of-file.  */
+  if (pfile->mi_valid && pfile->mi_cmacro == 0)
+    ifs->mi_cmacro = cmacro;
+  else
+    ifs->mi_cmacro = 0;
+
+  pfile->state.skipping = skip;
+  buffer->if_stack = ifs;
+}
+
+/* Read the tokens of the answer into the macro pool, in a directive
+   of type TYPE.  Only commit the memory if we intend it as permanent
+   storage, i.e. the #assert case.  Returns 0 on success, and sets
+   ANSWERP to point to the answer.  */
+static int
+parse_answer (cpp_reader *pfile, struct answer **answerp, int type)
+{
+  const cpp_token *paren;
+  struct answer *answer;
+  unsigned int acount;
+
+  /* In a conditional, it is legal to not have an open paren.  We
+     should save the following token in this case.  */
+  paren = cpp_get_token (pfile);
+
+  /* If not a paren, see if we're OK.  */
+  if (paren->type != CPP_OPEN_PAREN)
+    {
+      /* In a conditional no answer is a test for any answer.  It
+         could be followed by any token.  */
+      if (type == T_IF)
+	{
+	  _cpp_backup_tokens (pfile, 1);
+	  return 0;
+	}
+
+      /* #unassert with no answer is valid - it removes all answers.  */
+      if (type == T_UNASSERT && paren->type == CPP_EOF)
+	return 0;
+
+      cpp_error (pfile, CPP_DL_ERROR, "missing '(' after predicate");
+      return 1;
+    }
+
+  for (acount = 0;; acount++)
+    {
+      size_t room_needed;
+      const cpp_token *token = cpp_get_token (pfile);
+      cpp_token *dest;
+
+      if (token->type == CPP_CLOSE_PAREN)
+	break;
+
+      if (token->type == CPP_EOF)
+	{
+	  cpp_error (pfile, CPP_DL_ERROR, "missing ')' to complete answer");
+	  return 1;
+	}
+
+      /* struct answer includes the space for one token.  */
+      room_needed = (sizeof (struct answer) + acount * sizeof (cpp_token));
+
+      if (BUFF_ROOM (pfile->a_buff) < room_needed)
+	_cpp_extend_buff (pfile, &pfile->a_buff, sizeof (struct answer));
+
+      dest = &((struct answer *) BUFF_FRONT (pfile->a_buff))->first[acount];
+      *dest = *token;
+
+      /* Drop whitespace at start, for answer equivalence purposes.  */
+      if (acount == 0)
+	dest->flags &= ~PREV_WHITE;
+    }
+
+  if (acount == 0)
+    {
+      cpp_error (pfile, CPP_DL_ERROR, "predicate's answer is empty");
+      return 1;
+    }
+
+  answer = (struct answer *) BUFF_FRONT (pfile->a_buff);
+  answer->count = acount;
+  answer->next = NULL;
+  *answerp = answer;
+
+  return 0;
+}
+
+/* Parses an assertion directive of type TYPE, returning a pointer to
+   the hash node of the predicate, or 0 on error.  If an answer was
+   supplied, it is placed in ANSWERP, otherwise it is set to 0.  */
+static cpp_hashnode *
+parse_assertion (cpp_reader *pfile, struct answer **answerp, int type)
+{
+  cpp_hashnode *result = 0;
+  const cpp_token *predicate;
+
+  /* We don't expand predicates or answers.  */
+  pfile->state.prevent_expansion++;
+
+  *answerp = 0;
+  predicate = cpp_get_token (pfile);
+  if (predicate->type == CPP_EOF)
+    cpp_error (pfile, CPP_DL_ERROR, "assertion without predicate");
+  else if (predicate->type != CPP_NAME)
+    cpp_error (pfile, CPP_DL_ERROR, "predicate must be an identifier");
+  else if (parse_answer (pfile, answerp, type) == 0)
+    {
+      unsigned int len = NODE_LEN (predicate->val.node);
+      unsigned char *sym = (unsigned char *) alloca (len + 1);
+
+      /* Prefix '#' to get it out of macro namespace.  */
+      sym[0] = '#';
+      memcpy (sym + 1, NODE_NAME (predicate->val.node), len);
+      result = cpp_lookup (pfile, sym, len + 1);
+    }
+
+  pfile->state.prevent_expansion--;
+  return result;
+}
+
+/* Returns a pointer to the pointer to CANDIDATE in the answer chain,
+   or a pointer to NULL if the answer is not in the chain.  */
+static struct answer **
+find_answer (cpp_hashnode *node, const struct answer *candidate)
+{
+  unsigned int i;
+  struct answer **result;
+
+  for (result = &node->value.answers; *result; result = &(*result)->next)
+    {
+      struct answer *answer = *result;
+
+      if (answer->count == candidate->count)
+	{
+	  for (i = 0; i < answer->count; i++)
+	    if (! _cpp_equiv_tokens (&answer->first[i], &candidate->first[i]))
+	      break;
+
+	  if (i == answer->count)
+	    break;
+	}
+    }
+
+  return result;
+}
+
+/* Test an assertion within a preprocessor conditional.  Returns
+   nonzero on failure, zero on success.  On success, the result of
+   the test is written into VALUE, otherwise the value 0.  */
+int
+_cpp_test_assertion (cpp_reader *pfile, unsigned int *value)
+{
+  struct answer *answer;
+  cpp_hashnode *node;
+
+  node = parse_assertion (pfile, &answer, T_IF);
+
+  /* For recovery, an erroneous assertion expression is handled as a
+     failing assertion.  */
+  *value = 0;
+
+  if (node)
+    *value = (node->type == NT_ASSERTION &&
+	      (answer == 0 || *find_answer (node, answer) != 0));
+  else if (pfile->cur_token[-1].type == CPP_EOF)
+    _cpp_backup_tokens (pfile, 1);
+
+  /* We don't commit the memory for the answer - it's temporary only.  */
+  return node == 0;
+}
+
+/* Handle #assert.  */
+static void
+do_assert (cpp_reader *pfile)
+{
+  struct answer *new_answer;
+  cpp_hashnode *node;
+
+  node = parse_assertion (pfile, &new_answer, T_ASSERT);
+  if (node)
+    {
+      size_t answer_size;
+
+      /* Place the new answer in the answer list.  First check there
+         is not a duplicate.  */
+      new_answer->next = 0;
+      if (node->type == NT_ASSERTION)
+	{
+	  if (*find_answer (node, new_answer))
+	    {
+	      cpp_error (pfile, CPP_DL_WARNING, "\"%s\" re-asserted",
+			 NODE_NAME (node) + 1);
+	      return;
+	    }
+	  new_answer->next = node->value.answers;
+	}
+
+      answer_size = sizeof (struct answer) + ((new_answer->count - 1)
+					      * sizeof (cpp_token));
+      /* Commit or allocate storage for the object.  */
+      if (pfile->hash_table->alloc_subobject)
+	{
+	  struct answer *temp_answer = new_answer;
+	  new_answer = (struct answer *) pfile->hash_table->alloc_subobject
+            (answer_size);
+	  memcpy (new_answer, temp_answer, answer_size);
+	}
+      else
+	BUFF_FRONT (pfile->a_buff) += answer_size;
+
+      node->type = NT_ASSERTION;
+      node->value.answers = new_answer;
+      check_eol (pfile);
+    }
+}
+
+/* Handle #unassert.  */
+static void
+do_unassert (cpp_reader *pfile)
+{
+  cpp_hashnode *node;
+  struct answer *answer;
+
+  node = parse_assertion (pfile, &answer, T_UNASSERT);
+  /* It isn't an error to #unassert something that isn't asserted.  */
+  if (node && node->type == NT_ASSERTION)
+    {
+      if (answer)
+	{
+	  struct answer **p = find_answer (node, answer), *temp;
+
+	  /* Remove the answer from the list.  */
+	  temp = *p;
+	  if (temp)
+	    *p = temp->next;
+
+	  /* Did we free the last answer?  */
+	  if (node->value.answers == 0)
+	    node->type = NT_VOID;
+
+	  check_eol (pfile);
+	}
+      else
+	_cpp_free_definition (node);
+    }
+
+  /* We don't commit the memory for the answer - it's temporary only.  */
+}
+
+/* These are for -D, -U, -A.  */
+
+/* Process the string STR as if it appeared as the body of a #define.
+   If STR is just an identifier, define it with value 1.
+   If STR has anything after the identifier, then it should
+   be identifier=definition.  */
+void
+cpp_define (cpp_reader *pfile, const char *str)
+{
+  char *buf, *p;
+  size_t count;
+
+  /* Copy the entire option so we can modify it.
+     Change the first "=" in the string to a space.  If there is none,
+     tack " 1" on the end.  */
+
+  count = strlen (str);
+  buf = (char *) alloca (count + 3);
+  memcpy (buf, str, count);
+
+  p = strchr (str, '=');
+  if (p)
+    buf[p - str] = ' ';
+  else
+    {
+      buf[count++] = ' ';
+      buf[count++] = '1';
+    }
+  buf[count] = '\n';
+
+  run_directive (pfile, T_DEFINE, buf, count);
+}
+
+
+/* Use to build macros to be run through cpp_define() as
+   described above.
+   Example: cpp_define_formatted (pfile, "MACRO=%d", value);  */
+
+void
+cpp_define_formatted (cpp_reader *pfile, const char *fmt, ...)
+{
+  char *ptr = NULL;
+
+  va_list ap;
+  va_start (ap, fmt);
+  vasprintf (&ptr, fmt, ap);
+  va_end (ap);
+
+  cpp_define (pfile, ptr);
+  free (ptr);
+}
+
+
+/* Slight variant of the above for use by initialize_builtins.  */
+void
+_cpp_define_builtin (cpp_reader *pfile, const char *str)
+{
+  size_t len = strlen (str);
+  char *buf = (char *) alloca (len + 1);
+  memcpy (buf, str, len);
+  buf[len] = '\n';
+  run_directive (pfile, T_DEFINE, buf, len);
+}
+
+/* Process MACRO as if it appeared as the body of an #undef.  */
+void
+cpp_undef (cpp_reader *pfile, const char *macro)
+{
+  size_t len = strlen (macro);
+  char *buf = (char *) alloca (len + 1);
+  memcpy (buf, macro, len);
+  buf[len] = '\n';
+  run_directive (pfile, T_UNDEF, buf, len);
+}
+
+/* Like lex_macro_node, but read the input from STR.  */
+static cpp_hashnode *
+lex_macro_node_from_str (cpp_reader *pfile, const char *str)
+{
+  size_t len = strlen (str);
+  uchar *buf = (uchar *) alloca (len + 1);
+  cpp_hashnode *node;
+
+  memcpy (buf, str, len);
+  buf[len] = '\n';
+  cpp_push_buffer (pfile, buf, len, true);
+  node = lex_macro_node (pfile, true);
+  _cpp_pop_buffer (pfile);
+
+  return node;
+}
+
+/* If STR is a defined macro, return its definition node, else return NULL.  */
+cpp_macro *
+cpp_push_definition (cpp_reader *pfile, const char *str)
+{
+  cpp_hashnode *node = lex_macro_node_from_str (pfile, str);
+  if (node && node->type == NT_MACRO)
+    return node->value.macro;
+  else
+    return NULL;
+}
+
+/* Replace a previous definition DFN of the macro STR.  If DFN is NULL,
+   then the macro should be undefined.  */
+void
+cpp_pop_definition (cpp_reader *pfile, const char *str, cpp_macro *dfn)
+{
+  cpp_hashnode *node = lex_macro_node_from_str (pfile, str);
+  if (node == NULL)
+    return;
+
+  if (pfile->cb.before_define)
+    pfile->cb.before_define (pfile);
+
+  if (node->type == NT_MACRO)
+    {
+      if (pfile->cb.undef)
+	pfile->cb.undef (pfile, pfile->directive_line, node);
+      if (CPP_OPTION (pfile, warn_unused_macros))
+	_cpp_warn_if_unused_macro (pfile, node, NULL);
+    }
+  if (node->type != NT_VOID)
+    _cpp_free_definition (node);
+
+  if (dfn)
+    {
+      node->type = NT_MACRO;
+      node->value.macro = dfn;
+      if (! ustrncmp (NODE_NAME (node), DSC ("__STDC_")))
+	node->flags |= NODE_WARN;
+
+      if (pfile->cb.define)
+	pfile->cb.define (pfile, pfile->directive_line, node);
+    }
+}
+
+/* Process the string STR as if it appeared as the body of a #assert.  */
+void
+cpp_assert (cpp_reader *pfile, const char *str)
+{
+  handle_assertion (pfile, str, T_ASSERT);
+}
+
+/* Process STR as if it appeared as the body of an #unassert.  */
+void
+cpp_unassert (cpp_reader *pfile, const char *str)
+{
+  handle_assertion (pfile, str, T_UNASSERT);
+}
+
+/* Common code for cpp_assert (-A) and cpp_unassert (-A-).  */
+static void
+handle_assertion (cpp_reader *pfile, const char *str, int type)
+{
+  size_t count = strlen (str);
+  const char *p = strchr (str, '=');
+
+  /* Copy the entire option so we can modify it.  Change the first
+     "=" in the string to a '(', and tack a ')' on the end.  */
+  char *buf = (char *) alloca (count + 2);
+
+  memcpy (buf, str, count);
+  if (p)
+    {
+      buf[p - str] = '(';
+      buf[count++] = ')';
+    }
+  buf[count] = '\n';
+  str = buf;
+
+  run_directive (pfile, type, str, count);
+}
+
+/* The number of errors for a given reader.  */
+unsigned int
+cpp_errors (cpp_reader *pfile)
+{
+  return pfile->errors;
+}
+
+/* The options structure.  */
+cpp_options *
+cpp_get_options (cpp_reader *pfile)
+{
+  return &pfile->opts;
+}
+
+/* The callbacks structure.  */
+cpp_callbacks *
+cpp_get_callbacks (cpp_reader *pfile)
+{
+  return &pfile->cb;
+}
+
+/* Copy the given callbacks structure to our own.  */
+void
+cpp_set_callbacks (cpp_reader *pfile, cpp_callbacks *cb)
+{
+  pfile->cb = *cb;
+}
+
+/* The dependencies structure.  (Creates one if it hasn't already been.)  */
+struct deps *
+cpp_get_deps (cpp_reader *pfile)
+{
+  if (!pfile->deps)
+    pfile->deps = deps_init ();
+  return pfile->deps;
+}
+
+/* Push a new buffer on the buffer stack.  Returns the new buffer; it
+   doesn't fail.  It does not generate a file change call back; that
+   is the responsibility of the caller.  */
+cpp_buffer *
+cpp_push_buffer (cpp_reader *pfile, const uchar *buffer, size_t len,
+		 int from_stage3)
+{
+  cpp_buffer *new_buffer = XOBNEW (&pfile->buffer_ob, cpp_buffer);
+
+  /* Clears, amongst other things, if_stack and mi_cmacro.  */
+  memset (new_buffer, 0, sizeof (cpp_buffer));
+
+  new_buffer->next_line = new_buffer->buf = buffer;
+  new_buffer->rlimit = buffer + len;
+  new_buffer->from_stage3 = from_stage3;
+  new_buffer->prev = pfile->buffer;
+  new_buffer->need_line = true;
+
+  pfile->buffer = new_buffer;
+
+  return new_buffer;
+}
+
+/* Pops a single buffer, with a file change call-back if appropriate.
+   Then pushes the next -include file, if any remain.  */
+void
+_cpp_pop_buffer (cpp_reader *pfile)
+{
+  cpp_buffer *buffer = pfile->buffer;
+  struct _cpp_file *inc = buffer->file;
+  struct if_stack *ifs;
+
+  /* Walk back up the conditional stack till we reach its level at
+     entry to this file, issuing error messages.  */
+  for (ifs = buffer->if_stack; ifs; ifs = ifs->next)
+    cpp_error_with_line (pfile, CPP_DL_ERROR, ifs->line, 0,
+			 "unterminated #%s", dtable[ifs->type].name);
+
+  /* In case of a missing #endif.  */
+  pfile->state.skipping = 0;
+
+  /* _cpp_do_file_change expects pfile->buffer to be the new one.  */
+  pfile->buffer = buffer->prev;
+
+  free (buffer->notes);
+
+  /* Free the buffer object now; we may want to push a new buffer
+     in _cpp_push_next_include_file.  */
+  obstack_free (&pfile->buffer_ob, buffer);
+
+  if (inc)
+    {
+      _cpp_pop_file_buffer (pfile, inc);
+
+      _cpp_do_file_change (pfile, LC_LEAVE, 0, 0, 0);
+    }
+}
+
+/* Enter all recognized directives in the hash table.  */
+void
+_cpp_init_directives (cpp_reader *pfile)
+{
+  unsigned int i;
+  cpp_hashnode *node;
+
+  for (i = 0; i < (unsigned int) N_DIRECTIVES; i++)
+    {
+      node = cpp_lookup (pfile, dtable[i].name, dtable[i].length);
+      node->is_directive = 1;
+      node->directive_index = i;
+    }
+}