cpplex.c: Don't include sys/mman.h.

toplevel:
	* cpplex.c: Don't include sys/mman.h.
	(cpp_push_buffer, cpp_pop_buffer): Moved to cpplib.c.

	* cpplib.c: Include sys/mman.h and obstack.h.
	(cpp_push_buffer): Moved from cpplex.c; allocate buffers on an
	obstack.
	(cpp_pop_buffer): Moved from cpplex.c; free buffers from an obstack.
	(_cpp_unwind_if_stack): Now static, unwind_if_stack.  Don't
	bother freeing if stack entries (they will be freed with their buffer).
	(do_endif): Free if stack entries from the buffer obstack.
	(push_conditional): Allocate if stack entries from the buffer obstack.

	(find_answer): Rename to _cpp_find_answer.
	(do_assert, do_unassert): Update.

	* cpphash.h: Update prototypes.
	(xobnew): New convenience macro.
	* cpplib.h (struct cpp_reader): Add hash_ob and buffer_ob fields.
	Update comments.
	(struct cpp_hashnode): Remove disabled field.

	* cppinit.c: Don't include hashtab.h or splay-tree.h.
	(report_missing_guard): Moved to cppfiles.c.
	(cpp_reader_init): Call cpp_init_stacks, cpp_init_macros,
	cpp_init_includes.
	(cpp_cleanup): Call cpp_cleanup_stacks, cpp_cleanup_macros,
	cpp_cleanup_includes.  Don't destroy hashtab or
	all_include_files here.
	(cpp_finish): Use _cpp_report_missing_guards.

	* cppfiles.c (report_missing_guard): Moved from cppinit.c.
	(_cpp_init_include_table): Rename _cpp_init_includes.
	(_cpp_cleanup_includes, _cpp_report_missing_guards): New.

	* cppexp.c (parse_assertion): Update for new name of
	find_answer.

	* Makefile.in (cpplib.o, cpphash.o, cppinit.o): Update deps.

	* cpplib.c (do_ident): s/VSPACE/EOF/

testsuite:
	* gcc.dg/cpp/ident.c: New test.

From-SVN: r34870

gcc/ChangeLog

+2000-07-04  Zack Weinberg  <zack@wolery.cumb.org>
+
+	* cpplex.c: Don't include sys/mman.h.
+	(cpp_push_buffer, cpp_pop_buffer): Moved to cpplib.c.
+
+	* cpplib.c: Include sys/mman.h and obstack.h.
+	(cpp_push_buffer): Moved from cpplex.c; allocate buffers on an
+	obstack.
+	(cpp_pop_buffer): Moved from cpplex.c; free buffers from an obstack.
+	(_cpp_unwind_if_stack): Now static, unwind_if_stack.  Don't
+	bother freeing if stack entries (they will be freed with their buffer).
+	(do_endif): Free if stack entries from the buffer obstack.
+	(push_conditional): Allocate if stack entries from the buffer obstack.
+
+	(find_answer): Rename to _cpp_find_answer.
+	(do_assert, do_unassert): Update.
+
+	* cpphash.h: Update prototypes.
+	(xobnew): New convenience macro.
+	* cpplib.h (struct cpp_reader): Add hash_ob and buffer_ob fields.
+	Update comments.
+	(struct cpp_hashnode): Remove disabled field.
+
+	* cppinit.c: Don't include hashtab.h or splay-tree.h.
+	(report_missing_guard): Moved to cppfiles.c.
+	(cpp_reader_init): Call cpp_init_stacks, cpp_init_macros,
+	cpp_init_includes.
+	(cpp_cleanup): Call cpp_cleanup_stacks, cpp_cleanup_macros,
+	cpp_cleanup_includes.  Don't destroy hashtab or
+	all_include_files here.
+	(cpp_finish): Use _cpp_report_missing_guards.
+
+	* cppfiles.c (report_missing_guard): Moved from cppinit.c.
+	(_cpp_init_include_table): Rename _cpp_init_includes.
+	(_cpp_cleanup_includes, _cpp_report_missing_guards): New.
+
+	* cppexp.c (parse_assertion): Update for new name of
+	find_answer.
+
+	* Makefile.in (cpplib.o, cpphash.o, cppinit.o): Update deps.
+
+2000-07-04  Zack Weinberg  <zack@wolery.cumb.org>
+
+	* cpplib.c (do_ident): s/VSPACE/EOF/
+
 2000-07-05  Neil Booth  <NeilB@earthling.net>
 
 	* cpplex.c: Fix trigraph replacement within strings.

gcc/Makefile.in

@@ -1801,11 +1801,11 @@ cppulp.o:   cppulp.c   $(CONFIG_H) system.h output.h
 cpperror.o: cpperror.c $(CONFIG_H) $(LIBCPP_DEPS)
 cppexp.o:   cppexp.c   $(CONFIG_H) $(LIBCPP_DEPS)
 cpplex.o:   cpplex.c   $(CONFIG_H) $(LIBCPP_DEPS)
-cpplib.o:   cpplib.c   $(CONFIG_H) $(LIBCPP_DEPS)
-cpphash.o:  cpphash.c  $(CONFIG_H) $(LIBCPP_DEPS) $(HASHTAB_H)
+cpplib.o:   cpplib.c   $(CONFIG_H) $(LIBCPP_DEPS) $(OBSTACK_H)
+cpphash.o:  cpphash.c  $(CONFIG_H) $(LIBCPP_DEPS) $(OBSTACK_H) $(HASHTAB_H)
 cppfiles.o: cppfiles.c $(CONFIG_H) $(LIBCPP_DEPS) $(SPLAY_TREE_H) mkdeps.h
 
-cppinit.o: cppinit.c $(CONFIG_H) $(LIBCPP_DEPS) $(HASHTAB_H) $(SPLAY_TREE_H) \
+cppinit.o: cppinit.c $(CONFIG_H) $(LIBCPP_DEPS) \
 		mkdeps.h prefix.h output.h Makefile version.h
 	$(CC) $(ALL_CFLAGS) $(ALL_CPPFLAGS) $(INCLUDES) \
 	  $(PREPROCESSOR_DEFINES) \

gcc/cppexp.c

@@ -404,7 +404,7 @@ parse_assertion (pfile)
       /* If we get here, the syntax is valid.  */
       op.op = INT;
       op.value = (hp->type == T_ASSERTION &&
-		  (answer == 0 || *find_answer (hp, &answer->list) != 0));
+		  (answer == 0 || *_cpp_find_answer (hp, &answer->list) != 0));
 
       if (answer)
 	FREE_ANSWER (answer);

gcc/cppfiles.c

@@ -60,7 +60,8 @@ static ssize_t read_with_read	PARAMS ((cpp_buffer *, int, ssize_t));
 static ssize_t read_file	PARAMS ((cpp_buffer *, int, ssize_t));
 
 static void destroy_include_file_node	PARAMS ((splay_tree_value));
-static int close_cached_fd	PARAMS ((splay_tree_node, void *));
+static int close_cached_fd		PARAMS ((splay_tree_node, void *));
+static int report_missing_guard		PARAMS ((splay_tree_node, void *));
 
 #if 0
 static void hack_vms_include_specification PARAMS ((char *));
@@ -103,7 +104,7 @@ close_cached_fd (n, dummy)
 }
 
 void
-_cpp_init_include_table (pfile)
+_cpp_init_includes (pfile)
      cpp_reader *pfile;
 {
   pfile->all_include_files
@@ -112,6 +113,13 @@ _cpp_init_include_table (pfile)
 		      destroy_include_file_node);
 }
 
+void
+_cpp_cleanup_includes (pfile)
+     cpp_reader *pfile;
+{
+  splay_tree_delete (pfile->all_include_files);
+}
+
 /* Given a filename, look it up and possibly open it.  If the file
    does not exist, return NULL.  If the file does exist but doesn't
    need to be reread, return an include_file entry with fd == -1.
@@ -358,6 +366,38 @@ cpp_make_system_header (pfile, pbuf, flag)
     pbuf->inc->sysp = flag;
 }
 
+/* Report on all files that might benefit from a multiple include guard.
+   Triggered by -H.  */
+void
+_cpp_report_missing_guards (pfile)
+     cpp_reader *pfile;
+{
+  int banner = 0;
+  splay_tree_foreach (pfile->all_include_files, report_missing_guard,
+		      (PTR) &banner);
+}
+
+static int
+report_missing_guard (n, b)
+     splay_tree_node n;
+     void *b;
+{
+  struct include_file *f = (struct include_file *) n->value;
+  int *bannerp = (int *)b;
+
+  if (f && f->cmacro == 0 && f->include_count == 1)
+    {
+      if (*bannerp == 0)
+	{
+	  fputs (_("Multiple include guards may be useful for:\n"), stderr);
+	  *bannerp = 1;
+	}
+      fputs (f->name, stderr);
+      putc ('\n', stderr);
+    }
+  return 0;
+}
+
 #define PRINT_THIS_DEP(p, b) (CPP_PRINT_DEPS(p) > (b||p->system_include_depth))
 void
 _cpp_execute_include (pfile, f, len, no_reinclude, search_start, angle_brackets)

gcc/cpphash.c

@@ -26,10 +26,12 @@ Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 #include "config.h"
 #include "system.h"
 #include "cpplib.h"
-#include "hashtab.h"
 #include "cpphash.h"
+#include "hashtab.h"
+#include "obstack.h"
 
-#undef abort
+#define obstack_chunk_alloc xmalloc
+#define obstack_chunk_free free
 
 /* This is the second argument to eq_HASHNODE.  */
 struct hashdummy
@@ -43,9 +45,6 @@ struct hashdummy
 
 static unsigned int hash_HASHNODE PARAMS ((const void *));
 static int eq_HASHNODE		  PARAMS ((const void *, const void *));
-static void del_HASHNODE	  PARAMS ((void *));
-static cpp_hashnode *make_HASHNODE	  PARAMS ((const U_CHAR *, size_t,
-					   enum node_type, unsigned int));
 static int dump_hash_helper	  PARAMS ((void **, void *));
 
 static void dump_funlike_macro	PARAMS ((cpp_reader *, cpp_hashnode *));
@@ -105,41 +104,6 @@ eq_HASHNODE (x, y)
 	  && !ustrncmp (a->name, b->name, a->length));
 }
 
-/* Destroy a cpp_hashnode.  */
-static void
-del_HASHNODE (x)
-     void *x;
-{
-  cpp_hashnode *h = (cpp_hashnode *)x;
-
-  _cpp_free_definition (h);
-  free (h);
-}
-
-/* Allocate and initialize a cpp_hashnode structure.
-   Caller must fill in the value field.  */
-
-static cpp_hashnode *
-make_HASHNODE (name, len, type, hash)
-     const U_CHAR *name;
-     size_t len;
-     enum node_type type;
-     unsigned int hash;
-{
-  cpp_hashnode *hp = (cpp_hashnode *) xmalloc (sizeof (cpp_hashnode) + len);
-  U_CHAR *p = (U_CHAR *)hp + offsetof (cpp_hashnode, name);
-
-  hp->type = type;
-  hp->length = len;
-  hp->hash = hash;
-  hp->disabled = 0;
-
-  memcpy (p, name, len);
-  p[len] = 0;
-
-  return hp;
-}
-
 /* Find the hash node for name "name", of length LEN.  */
 
 cpp_hashnode *
@@ -151,6 +115,7 @@ cpp_lookup (pfile, name, len)
   struct hashdummy dummy;
   cpp_hashnode *new, **slot;
   unsigned int hash;
+  U_CHAR *p;
 
   dummy.name = name;
   dummy.length = len;
@@ -161,20 +126,42 @@ cpp_lookup (pfile, name, len)
   if (*slot)
     return *slot;
 
-  new = make_HASHNODE (name, len, T_VOID, hash);
+  /* Create a new hash node.  */
+  p = obstack_alloc (pfile->hash_ob, sizeof (cpp_hashnode) + len);
+  new = (cpp_hashnode *)p;
+  p += offsetof (cpp_hashnode, name);
+  
+  new->type = T_VOID;
+  new->length = len;
+  new->hash = hash;
+  new->fe_value = 0;
   new->value.expansion = NULL;
 
+  memcpy (p, name, len);
+  p[len] = 0;
+
   *slot = new;
   return new;
 }
 
-/* Init the hash table.  In here so it can see the hash and eq functions.  */
+/* Set up and tear down internal structures for macro expansion.  */
 void
-_cpp_init_macro_hash (pfile)
+_cpp_init_macros (pfile)
      cpp_reader *pfile;
 {
   pfile->hashtab = htab_create (HASHSIZE, hash_HASHNODE,
-				eq_HASHNODE, del_HASHNODE);
+				eq_HASHNODE, (htab_del) _cpp_free_definition);
+  pfile->hash_ob = xnew (struct obstack);
+  obstack_init (pfile->hash_ob);
+}
+
+void
+_cpp_cleanup_macros (pfile)
+     cpp_reader *pfile;
+{
+  htab_delete (pfile->hashtab);
+  obstack_free (pfile->hash_ob, 0);
+  free (pfile->hash_ob);
 }
 
 /* Free the definition of macro H.  */

gcc/cpphash.h

@@ -188,7 +188,8 @@ extern unsigned int _cpp_calc_hash	PARAMS ((const U_CHAR *, size_t));
 extern void _cpp_free_definition	PARAMS ((cpp_hashnode *));
 extern int _cpp_create_definition	PARAMS ((cpp_reader *, cpp_hashnode *));
 extern void _cpp_dump_definition	PARAMS ((cpp_reader *, cpp_hashnode *));
-extern void _cpp_init_macro_hash	PARAMS ((cpp_reader *));
+extern void _cpp_init_macros		PARAMS ((cpp_reader *));
+extern void _cpp_cleanup_macros		PARAMS ((cpp_reader *));
 extern void _cpp_dump_macro_hash	PARAMS ((cpp_reader *));
 
 /* In cppfiles.c */
@@ -199,7 +200,9 @@ extern void _cpp_execute_include	PARAMS ((cpp_reader *, const U_CHAR *,
 						 int));
 extern int _cpp_compare_file_date       PARAMS ((cpp_reader *, const U_CHAR *,
                                                  unsigned int, int));
-extern void _cpp_init_include_table	PARAMS ((cpp_reader *));
+extern void _cpp_report_missing_guards	PARAMS ((cpp_reader *));
+extern void _cpp_init_includes		PARAMS ((cpp_reader *));
+extern void _cpp_cleanup_includes	PARAMS ((cpp_reader *));
 extern const char *_cpp_fake_include	PARAMS ((cpp_reader *, const char *));
 
 /* In cppexp.c */
@@ -241,15 +244,17 @@ extern const struct directive *_cpp_check_directive
 			PARAMS ((cpp_reader *, const cpp_token *, int));
 extern const struct directive *_cpp_check_linemarker
 			PARAMS ((cpp_reader *, const cpp_token *, int));
-extern void _cpp_unwind_if_stack	PARAMS ((cpp_reader *, cpp_buffer *));
-extern cpp_hashnode * _cpp_parse_assertion PARAMS ((cpp_reader *,
+extern cpp_hashnode *_cpp_parse_assertion PARAMS ((cpp_reader *,
 						    struct answer **));
-extern struct answer** find_answer	PARAMS ((cpp_hashnode *,
+extern struct answer **_cpp_find_answer	PARAMS ((cpp_hashnode *,
 						 const cpp_toklist *));
+extern void _cpp_init_stacks	PARAMS ((cpp_reader *));
+extern void _cpp_cleanup_stacks	PARAMS ((cpp_reader *));
 
 /* Utility routines and macros.  */
 #define xnew(T)		(T *) xmalloc (sizeof(T))
 #define xnewvec(T, N)	(T *) xmalloc (sizeof(T) * (N))
+#define xobnew(O, T)	(T *) obstack_alloc (O, sizeof(T))
 
 /* These are inline functions instead of macros so we can get type
    checking.  */

gcc/cppinit.c

@@ -21,8 +21,6 @@ Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
 
 #include "config.h"
 #include "system.h"
-#include "hashtab.h"
-#include "splay-tree.h"
 #include "cpplib.h"
 #include "cpphash.h"
 #include "output.h"
@@ -225,7 +223,6 @@ static int opt_comp			PARAMS ((const void *, const void *));
 #endif
 static int parse_option			PARAMS ((const char *));
 static int handle_option		PARAMS ((cpp_reader *, int, char **));
-static int report_missing_guard		PARAMS ((splay_tree_node, void *));
 
 /* Fourth argument to append_include_chain: chain to use */
 enum { QUOTE = 0, BRACKET, SYSTEM, AFTER };
@@ -533,8 +530,9 @@ cpp_reader_init (pfile)
   CPP_OPTION (pfile, pending) =
     (struct cpp_pending *) xcalloc (1, sizeof (struct cpp_pending));
 
-  _cpp_init_macro_hash (pfile);
-  _cpp_init_include_table (pfile);
+  _cpp_init_stacks (pfile);
+  _cpp_init_macros (pfile);
+  _cpp_init_includes (pfile);
 }
 
 /* Initialize a cpp_printer structure.  As a side effect, open the
@@ -580,8 +578,9 @@ cpp_cleanup (pfile)
   if (pfile->deps)
     deps_free (pfile->deps);
 
-  htab_delete (pfile->hashtab);
-  splay_tree_delete (pfile->all_include_files);
+  _cpp_cleanup_stacks (pfile);
+  _cpp_cleanup_macros (pfile);
+  _cpp_cleanup_includes (pfile);
   _cpp_free_temp_tokens (pfile);
 }
 
@@ -1009,27 +1008,6 @@ cpp_start_read (pfile, print, fname)
   return 1;
 }
 
-static int
-report_missing_guard (n, b)
-     splay_tree_node n;
-     void *b;
-{
-  struct include_file *f = (struct include_file *) n->value;
-  int *bannerp = (int *)b;
-
-  if (f && f->cmacro == 0 && f->include_count == 1)
-    {
-      if (*bannerp == 0)
-	{
-	  fputs (_("Multiple include guards may be useful for:\n"), stderr);
-	  *bannerp = 1;
-	}
-      fputs (f->name, stderr);
-      putc ('\n', stderr);
-    }
-  return 0;
-}
-
 /* This is called at the end of preprocessing.  It pops the
    last buffer and writes dependency output.  It should also
    clear macro definitions, such that you could call cpp_start_read
@@ -1085,11 +1063,7 @@ cpp_finish (pfile, print)
 
   /* Report on headers that could use multiple include guards.  */
   if (CPP_OPTION (pfile, print_include_names))
-    {
-      int banner = 0;
-      splay_tree_foreach (pfile->all_include_files, report_missing_guard,
-			  (void *) &banner);
-    }
+    _cpp_report_missing_guards (pfile);
 }
 
 static void

gcc/cpplex.c

@@ -56,10 +56,6 @@ o Correct pastability test for CPP_NAME and CPP_NUMBER.
 #include "cpphash.h"
 #include "symcat.h"
 
-#ifdef HAVE_MMAP_FILE
-# include <sys/mman.h>
-#endif
-
 #define auto_expand_name_space(list) \
     _cpp_expand_name_space ((list), 1 + (list)->name_cap / 2)
 static void safe_fwrite		PARAMS ((cpp_reader *, const U_CHAR *,
@@ -227,78 +223,6 @@ _cpp_grow_token_buffer (pfile, n)
   CPP_SET_WRITTEN (pfile, old_written);
 }
 
-/* Allocate a new cpp_buffer for PFILE, and push it on the input buffer stack.
-   If BUFFER != NULL, then use the LENGTH characters in BUFFER
-   as the new input buffer.
-   Return the new buffer, or NULL on failure.  */
-
-cpp_buffer *
-cpp_push_buffer (pfile, buffer, length)
-     cpp_reader *pfile;
-     const U_CHAR *buffer;
-     long length;
-{
-  cpp_buffer *buf = CPP_BUFFER (pfile);
-  cpp_buffer *new;
-  if (++pfile->buffer_stack_depth == CPP_STACK_MAX)
-    {
-      cpp_fatal (pfile, "macro or #include recursion too deep");
-      return NULL;
-    }
-
-  new = (cpp_buffer *) xcalloc (1, sizeof (cpp_buffer));
-
-  new->buf = new->cur = buffer;
-  new->rlimit = buffer + length;
-  new->prev = buf;
-  new->line_base = NULL;
-
-  CPP_BUFFER (pfile) = new;
-  return new;
-}
-
-cpp_buffer *
-cpp_pop_buffer (pfile)
-     cpp_reader *pfile;
-{
-  cpp_buffer *buf = CPP_BUFFER (pfile);
-
-  if (buf->inc)
-    {
-      _cpp_unwind_if_stack (pfile, buf);
-      if (buf->buf)
-	{
-#ifdef HAVE_MMAP_FILE
-	  if (buf->mapped)
-	    munmap ((caddr_t) buf->buf, buf->rlimit - buf->buf);
-	  else
-#endif
-	    free ((PTR) buf->buf);
-	}
-      if (pfile->system_include_depth)
-	pfile->system_include_depth--;
-      if (pfile->include_depth)
-	pfile->include_depth--;
-      if (pfile->potential_control_macro)
-	{
-	  if (buf->inc->cmacro != NEVER_REREAD)
-	    buf->inc->cmacro = pfile->potential_control_macro;
-	  pfile->potential_control_macro = 0;
-	}
-      pfile->input_stack_listing_current = 0;
-      /* If the file will not be included again, then close it.  */
-      if (DO_NOT_REREAD (buf->inc))
-	{
-	  close (buf->inc->fd);
-	  buf->inc->fd = -1;
-	}
-    }
-  CPP_BUFFER (pfile) = CPP_PREV_BUFFER (buf);
-  free (buf);
-  pfile->buffer_stack_depth--;
-  return CPP_BUFFER (pfile);
-}
-
 /* Deal with the annoying semantics of fwrite.  */
 static void
 safe_fwrite (pfile, buf, len, fp)

gcc/cpplib.c

@@ -25,8 +25,13 @@ Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
 #include "cpplib.h"
 #include "cpphash.h"
 #include "intl.h"
+#include "obstack.h"
 #include "symcat.h"
 
+#ifdef HAVE_MMAP_FILE
+# include <sys/mman.h>
+#endif
+
 /* Stack of conditionals currently in progress
    (including both successful and failing conditionals).  */
 
@@ -43,21 +48,24 @@ struct if_stack
 /* Forward declarations.  */
 
 static void validate_else	PARAMS ((cpp_reader *, const U_CHAR *));
-static int parse_include	PARAMS ((cpp_reader *, const U_CHAR *, int,
+static int  parse_include	PARAMS ((cpp_reader *, const U_CHAR *, int,
 					 const U_CHAR **, unsigned int *,
 					 int *));
 static void push_conditional	PARAMS ((cpp_reader *, int, int,
 					 const cpp_hashnode *));
 static void pass_thru_directive	PARAMS ((cpp_reader *));
-static int read_line_number	PARAMS ((cpp_reader *, int *));
-static int strtoul_for_line	PARAMS ((const U_CHAR *, unsigned int,
+static int  read_line_number	PARAMS ((cpp_reader *, int *));
+static int  strtoul_for_line	PARAMS ((const U_CHAR *, unsigned int,
 					 unsigned long *));
 
-static const cpp_hashnode *parse_ifdef	PARAMS ((cpp_reader *, const U_CHAR *));
-static const cpp_hashnode *detect_if_not_defined
-					PARAMS ((cpp_reader *));
-static cpp_hashnode *get_define_node	PARAMS ((cpp_reader *));
-static void dump_macro_name PARAMS ((cpp_reader *, cpp_hashnode *));
+static const cpp_hashnode *
+	    parse_ifdef		PARAMS ((cpp_reader *, const U_CHAR *));
+static const cpp_hashnode *
+	    detect_if_not_defined PARAMS ((cpp_reader *));
+static cpp_hashnode *
+	    get_define_node	PARAMS ((cpp_reader *));
+static void dump_macro_name 	PARAMS ((cpp_reader *, cpp_hashnode *));
+static void unwind_if_stack	PARAMS ((cpp_reader *, cpp_buffer *));
 
 /* Utility.  */
 #define str_match(sym, len, str) \
@@ -644,7 +652,7 @@ do_ident (pfile)
   /* Next token should be a string constant.  */
   if (cpp_get_token (pfile)->type == CPP_STRING)
     /* And then a newline.  */
-    if (cpp_get_token (pfile)->type == CPP_VSPACE)
+    if (cpp_get_token (pfile)->type == CPP_EOF)
       {
 	/* Good - ship it.  */
 	pass_thru_directive (pfile);
@@ -1150,7 +1158,7 @@ do_endif (pfile)
       CPP_BUFFER (pfile)->if_stack = ifs->next;
       pfile->skipping = ifs->was_skipping;
       pfile->potential_control_macro = ifs->cmacro;
-      free (ifs);
+      obstack_free (pfile->buffer_ob, ifs);
     }
   return 0;
 }
@@ -1169,7 +1177,7 @@ push_conditional (pfile, skip, type, cmacro)
 {
   struct if_stack *ifs;
 
-  ifs = (struct if_stack *) xmalloc (sizeof (struct if_stack));
+  ifs = xobnew (pfile->buffer_ob, struct if_stack);
   ifs->lineno = _cpp_get_line (pfile, &ifs->colno);
   ifs->next = CPP_BUFFER (pfile)->if_stack;
   ifs->cmacro = cmacro;
@@ -1197,8 +1205,8 @@ validate_else (pfile, directive)
 /* Called when we reach the end of a file.  Walk back up the
    conditional stack till we reach its level at entry to this file,
    issuing error messages.  Then force skipping off.  */
-void
-_cpp_unwind_if_stack (pfile, pbuf)
+static void
+unwind_if_stack (pfile, pbuf)
      cpp_reader *pfile;
      cpp_buffer *pbuf;
 {
@@ -1209,7 +1217,7 @@ _cpp_unwind_if_stack (pfile, pbuf)
       cpp_error_with_line (pfile, ifs->lineno, ifs->colno, "unterminated #%s",
 			   dtable[ifs->type].name);
       nifs = ifs->next;
-      free (ifs);
+      /* No need to free - they'll all go away with the buffer.  */
     }
   pfile->skipping = 0;
 }
@@ -1330,7 +1338,7 @@ _cpp_parse_assertion (pfile, answerp)
 /* Returns a pointer to the pointer to the answer in the answer chain,
    or a pointer to NULL if the answer is not in the chain.  */
 struct answer **
-find_answer (node, candidate)
+_cpp_find_answer (node, candidate)
      cpp_hashnode *node;
      const cpp_toklist *candidate;
 {
@@ -1362,7 +1370,7 @@ do_assert (pfile)
 
       if (node->type == T_ASSERTION)
 	{
-	  if (*find_answer (node, &new_answer->list))
+	  if (*_cpp_find_answer (node, &new_answer->list))
 	    goto err;
 	  new_answer->next = node->value.answers;
 	}
@@ -1393,7 +1401,7 @@ do_unassert (pfile)
 	{
 	  if (answer)
 	    {
-	      struct answer **p = find_answer (node, &answer->list);
+	      struct answer **p = _cpp_find_answer (node, &answer->list);
 
 	      temp = *p;
 	      if (temp)
@@ -1503,3 +1511,93 @@ cpp_defined (pfile, id, len)
     }
   return (hp->type != T_VOID);
 }
+
+/* Allocate a new cpp_buffer for PFILE, and push it on the input buffer stack.
+   If BUFFER != NULL, then use the LENGTH characters in BUFFER
+   as the new input buffer.
+   Return the new buffer, or NULL on failure.  */
+
+cpp_buffer *
+cpp_push_buffer (pfile, buffer, length)
+     cpp_reader *pfile;
+     const U_CHAR *buffer;
+     long length;
+{
+  cpp_buffer *buf = CPP_BUFFER (pfile);
+  cpp_buffer *new;
+  if (++pfile->buffer_stack_depth == CPP_STACK_MAX)
+    {
+      cpp_fatal (pfile, "#include recursion too deep");
+      return NULL;
+    }
+
+  new = xobnew (pfile->buffer_ob, cpp_buffer);
+  memset (new, 0, sizeof (cpp_buffer));
+
+  new->buf = new->cur = buffer;
+  new->rlimit = buffer + length;
+  new->prev = buf;
+
+  CPP_BUFFER (pfile) = new;
+  return new;
+}
+
+cpp_buffer *
+cpp_pop_buffer (pfile)
+     cpp_reader *pfile;
+{
+  cpp_buffer *buf = CPP_BUFFER (pfile);
+
+  unwind_if_stack (pfile, buf);
+#ifdef HAVE_MMAP_FILE
+  if (buf->mapped)
+    munmap ((caddr_t) buf->buf, buf->rlimit - buf->buf);
+  else
+#endif
+    if (buf->inc)
+      free ((PTR) buf->buf);
+
+  if (buf->inc)
+    {
+      if (pfile->system_include_depth)
+	pfile->system_include_depth--;
+      if (pfile->include_depth)
+	pfile->include_depth--;
+      if (pfile->potential_control_macro)
+	{
+	  if (buf->inc->cmacro != NEVER_REREAD)
+	    buf->inc->cmacro = pfile->potential_control_macro;
+	  pfile->potential_control_macro = 0;
+	}
+      pfile->input_stack_listing_current = 0;
+      /* If the file will not be included again, then close it.  */
+      if (DO_NOT_REREAD (buf->inc))
+	{
+	  close (buf->inc->fd);
+	  buf->inc->fd = -1;
+	}
+    }
+
+  CPP_BUFFER (pfile) = CPP_PREV_BUFFER (buf);
+  obstack_free (pfile->buffer_ob, buf);
+  pfile->buffer_stack_depth--;
+  return CPP_BUFFER (pfile);
+}
+
+#define obstack_chunk_alloc xmalloc
+#define obstack_chunk_free free
+void
+_cpp_init_stacks (pfile)
+     cpp_reader *pfile;
+{
+  pfile->buffer_ob = xnew (struct obstack);
+  obstack_init (pfile->buffer_ob);
+}
+
+void
+_cpp_cleanup_stacks (pfile)
+     cpp_reader *pfile;
+{
+  obstack_free (pfile->buffer_ob, 0);
+  free (pfile->buffer_ob);
+}

gcc/cpplib.h

@@ -476,7 +476,7 @@ struct cpp_reader
   /* Hash table of macros and assertions.  See cpphash.c */
   struct htab *hashtab;
 
-  /* Hash table of other included files.  See cppfiles.c */
+  /* Tree of other included files.  See cppfiles.c */
   struct splay_tree_s *all_include_files;
 
   /* Chain of `actual directory' file_name_list entries,
@@ -527,6 +527,14 @@ struct cpp_reader
   /* Buffer of -M output.  */
   struct deps *deps;
 
+  /* Obstack holding all macro hash nodes.  This never shrinks.
+     See cpphash.c */
+  struct obstack *hash_ob;
+
+  /* Obstack holding buffer and conditional structures.  This is a
+     real stack.  See cpplib.c */
+  struct obstack *buffer_ob;
+
   /* User visible options.  */
   struct cpp_options opts;
 
@@ -625,7 +633,6 @@ struct cpp_hashnode
   unsigned int hash;			/* cached hash value */
   unsigned short length;		/* length of name */
   ENUM_BITFIELD(node_type) type : 8;	/* node type */
-  char disabled;			/* macro turned off for rescan? */
 
   union
   {

gcc/testsuite/ChangeLog

+2000-07-04  Zack Weinberg  <zack@wolery.cumb.org>
+
+	* gcc.dg/cpp/ident.c: New test.
+
 2000-07-05  Neil Booth  <NeilB@earthling.net>
 
 	* gcc.dg/cpp/lexident.c, gcc.dg/cpp/lexnum.c,

gcc/testsuite/gcc.dg/cpp/ident.c

+/* Test #ident.  */
+/* { dg-do compile } */
+/* { dg-options "" } */ /* shut off -pedantic */
+
+#ident "this is an ident"
+
+int dummy(void) { return 12; }
+
+/* { dg-final { scan-assembler ident.c "this is an ident" } } */