c-common.c (allow_pch): Remove.

2003-07-29  Geoffrey Keating  <geoffk@apple.com>

	* c-common.c (allow_pch): Remove.
	* c-common.h (allow_pch): Remove.
	(c_common_no_more_pch): Declare.
	* c-lex.c (c_lex): Call c_common_no_more_pch when appropriate.
	* c-pch.c: Include hosthooks.h.
	(c_common_valid_pch): Don't check allow_pch.
	(c_common_read_pch): Clear valid_pch to prevent reading PCH files.
	(c_common_no_more_pch): New.
	* ggc-common.c: Include hosthooks.h.
	(gt_pch_save): Call gt_pch_get_address.
	(gt_pch_restore): Call gt_pch_use_address.
	* hooks.c (hook_voidp_size_t_null): New.
	(hook_bool_voidp_size_t_false): New.
	* hooks.h (hook_voidp_size_t_null): New.
	(hook_bool_voidp_size_t_false): New.
	* hosthooks-def.h (HOST_HOOKS_GT_PCH_GET_ADDRESS): New.
	(HOST_HOOKS_GT_PCH_USE_ADDRESS): New.
	(HOST_HOOKS_INITIALIZER): Add HOST_HOOKS_GT_PCH_GET_ADDRESS,
	HOST_HOOKS_GT_PCH_USE_ADDRESS.
	* hosthooks.h (struct host_hooks): Add gt_pch_get_address,
	gt_pch_use_address.
	* doc/hostconfig.texi (Host Common): Document
	HOST_HOOKS_GT_PCH_GET_ADDRESS, HOST_HOOKS_GT_PCH_USE_ADDRESS.
	* Makefile.in (c-pch.o): Depend on hosthooks.h.
	(ggc-common.o): Likewise.

	* config/rs6000/host-darwin.c (HOST_HOOKS_GT_PCH_GET_ADDRESS): Define.
	(HOST_HOOKS_GT_PCH_USE_ADDRESS): Define.
	(pch_address_space): New.
	(darwin_rs6000_gt_pch_get_address): New.
	(darwin_rs6000_gt_pch_use_address): New.

Index: cp/ChangeLog
2003-07-29  Geoffrey Keating  <geoffk@apple.com>

	* parser.c (cp_lexer_new_main): Use c_common_no_more_pch instead
	of setting valid_pch by hand.

From-SVN: r69944

gcc/ChangeLog

@@ -1,3 +1,37 @@
+2003-07-29  Geoffrey Keating  <geoffk@apple.com>
+
+	* c-common.c (allow_pch): Remove.
+	* c-common.h (allow_pch): Remove.
+	(c_common_no_more_pch): Declare.
+	* c-lex.c (c_lex): Call c_common_no_more_pch when appropriate.
+	* c-pch.c: Include hosthooks.h.
+	(c_common_valid_pch): Don't check allow_pch.
+	(c_common_read_pch): Clear valid_pch to prevent reading PCH files.
+	(c_common_no_more_pch): New.
+	* ggc-common.c: Include hosthooks.h.
+	(gt_pch_save): Call gt_pch_get_address.
+	(gt_pch_restore): Call gt_pch_use_address.
+	* hooks.c (hook_voidp_size_t_null): New.
+	(hook_bool_voidp_size_t_false): New.
+	* hooks.h (hook_voidp_size_t_null): New.
+	(hook_bool_voidp_size_t_false): New.
+	* hosthooks-def.h (HOST_HOOKS_GT_PCH_GET_ADDRESS): New.
+	(HOST_HOOKS_GT_PCH_USE_ADDRESS): New.
+	(HOST_HOOKS_INITIALIZER): Add HOST_HOOKS_GT_PCH_GET_ADDRESS,
+	HOST_HOOKS_GT_PCH_USE_ADDRESS.
+	* hosthooks.h (struct host_hooks): Add gt_pch_get_address,
+	gt_pch_use_address.
+	* doc/hostconfig.texi (Host Common): Document
+	HOST_HOOKS_GT_PCH_GET_ADDRESS, HOST_HOOKS_GT_PCH_USE_ADDRESS.
+	* Makefile.in (c-pch.o): Depend on hosthooks.h.
+	(ggc-common.o): Likewise.
+
+	* config/rs6000/host-darwin.c (HOST_HOOKS_GT_PCH_GET_ADDRESS): Define.
+	(HOST_HOOKS_GT_PCH_USE_ADDRESS): Define.
+	(pch_address_space): New.
+	(darwin_rs6000_gt_pch_get_address): New.
+	(darwin_rs6000_gt_pch_use_address): New.
+
 2003-07-29  Neil Booth  <neil@daikokuya.co.uk>
 
 	* Makefile.in (LIBCPP_DEPS): Add HASHTAB_H.

gcc/Makefile.in

@@ -1351,8 +1351,8 @@ c-dump.o : c-dump.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) $(TREE_H) \
 	$(C_TREE_H) tree-dump.h
 
 c-pch.o : c-pch.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(CPPLIB_H) $(TREE_H) \
-	$(C_COMMON_H) output.h toplev.h c-pragma.h $(GGC_H) debug.h langhooks.h \
+	$(C_COMMON_H) output.h toplev.h c-pragma.h $(GGC_H) debug.h \
-	flags.h
+	langhooks.h flags.h hosthooks.h
 
 # Language-independent files.
 
@@ -1433,7 +1433,7 @@ gtype-desc.o: gtype-desc.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) varray.h
 	ssa.h cselib.h insn-addr.h
 
 ggc-common.o: ggc-common.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(GGC_H) \
-	$(HASHTAB_H) toplev.h $(PARAMS_H)
+	$(HASHTAB_H) toplev.h $(PARAMS_H) hosthooks.h
 
 ggc-simple.o: ggc-simple.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) $(RTL_H) $(TREE_H) \
 	flags.h $(GGC_H) varray.h $(TIMEVAR_H) $(TM_P_H) $(PARAMS_H)

gcc/c-common.c

@@ -187,10 +187,6 @@ tree c_global_trees[CTI_MAX];
    langhook should take care of initialization of this array.  */
 
 bool statement_code_p[MAX_TREE_CODES];
-
-/* Nonzero if we can read a PCH file now.  */
-
-int allow_pch = 1;
 
 /* Switches common to the C front ends.  */
 

gcc/c-common.h

@@ -363,10 +363,6 @@ struct c_lang_decl GTY(()) {
      heuristics regarding optimization.  */
 #define DECL_ESTIMATED_INSNS(NODE) \
   (FUNCTION_DECL_CHECK (NODE)->decl.u1.i)
-
-/* Nonzero if we can read a PCH file now.  */
-
-extern int allow_pch;
 
 /* Switches common to the C front ends.  */
 
@@ -1314,6 +1310,7 @@ extern int c_common_valid_pch (cpp_reader *pfile, const char *name, int fd);
 extern void c_common_read_pch (cpp_reader *pfile, const char *name, int fd,
 			       const char *orig);
 extern void c_common_write_pch (void);
+extern void c_common_no_more_pch (void);
 extern void builtin_define_with_value (const char *, const char *, int);
 extern void c_stddef_cpp_builtins (void);
 extern void fe_file_change (const struct line_map *);

gcc/c-lex.c

@@ -320,6 +320,7 @@ c_lex (tree *value)
 {
   const cpp_token *tok;
   location_t atloc;
+  static bool no_more_pch;
 
  retry:
   tok = get_nonpadding_token ();
@@ -421,6 +422,12 @@ c_lex (tree *value)
       break;
     }
 
+  if (! no_more_pch)
+    {
+      no_more_pch = true;
+      c_common_no_more_pch ();
+    }
+
   return tok->type;
 }
 

gcc/c-pch.c

@@ -31,6 +31,7 @@ Boston, MA 02111-1307, USA.  */
 #include "c-pragma.h"
 #include "ggc.h"
 #include "langhooks.h"
+#include "hosthooks.h"
 
 struct c_pch_validity
 {
@@ -164,9 +165,6 @@ c_common_valid_pch (cpp_reader *pfile, const char *name, int fd)
   const char *pch_ident;
   struct c_pch_validity v;
 
-  if (! allow_pch)
-    return 2;
-
   /* Perform a quick test of whether this is a valid
      precompiled header for the current language.  */
 
@@ -244,7 +242,7 @@ c_common_read_pch (cpp_reader *pfile, const char *name,
       return;
     }
 
-  allow_pch = 0;
+  cpp_get_callbacks (parse_in)->valid_pch = NULL;
 
   if (fread (&h, sizeof (h), 1, f) != 1)
     {
@@ -274,3 +272,15 @@ c_common_read_pch (cpp_reader *pfile, const char *name,
 
   fclose (f);
 }
+
+/* Indicate that no more PCH files should be read.  */
+
+void
+c_common_no_more_pch (void)
+{
+  if (cpp_get_callbacks (parse_in)->valid_pch)
+    {
+      cpp_get_callbacks (parse_in)->valid_pch = NULL;
+      host_hooks.gt_pch_use_address (NULL, 0);
+    }
+}

gcc/config/rs6000/host-darwin.c

@@ -23,6 +23,7 @@
 #include "coretypes.h"
 #include <signal.h>
 #include <sys/ucontext.h>
+#include <sys/mman.h>
 #include "hosthooks.h"
 #include "hosthooks-def.h"
 #include "toplev.h"
@@ -135,5 +136,54 @@ darwin_rs6000_extra_signals (void)
   if (sigaction (SIGSEGV, &sact, 0) < 0) 
     fatal_error ("While setting up signal handler: %m");
 }
+
+static void * darwin_rs6000_gt_pch_get_address (size_t);
+static bool darwin_rs6000_gt_pch_use_address (void *, size_t);
+
+#undef HOST_HOOKS_GT_PCH_GET_ADDRESS
+#define HOST_HOOKS_GT_PCH_GET_ADDRESS darwin_rs6000_gt_pch_get_address
+#undef HOST_HOOKS_GT_PCH_USE_ADDRESS
+#define HOST_HOOKS_GT_PCH_USE_ADDRESS darwin_rs6000_gt_pch_use_address
+
+
+/* Yes, this is really supposed to work.  */
+static char pch_address_space[1024*1024*1024] __attribute__((aligned (4096)));
+
+/* Return the address of the PCH address space, if the PCH will fit in it.  */
+
+static void *
+darwin_rs6000_gt_pch_get_address (size_t sz)
+{
+  if (sz <= sizeof (pch_address_space))
+    return pch_address_space;
+  else
+    return NULL;
+}
+
+/* Check ADDR and SZ for validity, and deallocate (using munmap) that part of
+   pch_address_space beyond SZ.  */
+
+static bool
+darwin_rs6000_gt_pch_use_address (void *addr, size_t sz)
+{
+  const size_t pagesize = getpagesize();
+  bool result;
+
+  if ((size_t)pch_address_space % pagesize != 0
+      || sizeof (pch_address_space) % pagesize != 0)
+    abort ();
+  
+  result = (addr == pch_address_space && sz <= sizeof (pch_address_space));
+  if (! result)
+    sz = 0;
+
+  /* Round the size to a whole page size.  Normally this is a no-op.  */
+  sz = (sz + pagesize - 1) / pagesize * pagesize;
+
+  if (munmap (pch_address_space + sz, sizeof (pch_address_space) - sz) != 0)
+    fatal_error ("couldn't unmap pch_address_space: %m\n");
+
+  return result;
+}
 
 const struct host_hooks host_hooks = HOST_HOOKS_INITIALIZER;

gcc/cp/ChangeLog

@@ -1,3 +1,8 @@
+2003-07-29  Geoffrey Keating  <geoffk@apple.com>
+
+	* parser.c (cp_lexer_new_main): Use c_common_no_more_pch instead
+	of setting valid_pch by hand.
+
 2003-07-29  Rainer Orth  <ro@TechFak.Uni-Bielefeld.DE>
 
 	* decl.c (finish_enum): Initialize underlying_type.

gcc/cp/parser.c

@@ -302,7 +302,7 @@ cp_lexer_new_main (void)
      which is a GC collection point.  So we have to grab the first
      token before allocating any memory.  */
   cp_lexer_get_preprocessor_token (NULL, &first_token);
-  cpp_get_callbacks (parse_in)->valid_pch = NULL;
+  c_common_no_more_pch ();
 
   /* Allocate the memory.  */
   lexer = ggc_alloc_cleared (sizeof (cp_lexer));

gcc/doc/hostconfig.texi

@@ -42,6 +42,39 @@ This host hook is used to set up handling for extra signals.  The most
 common thing to do in this hook is to detect stack overflow.
 @end deftypefn
 
+@deftypefn {Host Hook} void * HOST_HOOKS_GT_PCH_GET_ADDRESS (size_t @var{size})
+This host hook returns the address of some space in which a PCH may be
+loaded with @samp{HOST_HOOKS_PCH_LOAD_PCH}.  The space will need to
+have @var{size} bytes.  If insufficient space is available,
+@samp{NULL} may be returned; the PCH machinery will try to find a
+suitable address using a heuristic.
+
+The memory does not have to be available now.  In fact, usually
+@samp{HOST_HOOKS_PCH_LOAD_PCH} will already have been called.  The memory
+need only be available in future invocations of GCC.
+@end deftypefn
+
+@deftypefn {Host Hook} bool HOST_HOOKS_GT_PCH_USE_ADDRESS (size_t @var{size}, void * @var{address})
+This host hook is called when a PCH file is about to be loaded.  If
+@var{address} is the address that would have been returned by
+@samp{HOST_HOOKS_PCH_MEMORY_ADDRESS}, and @var{size} is smaller than
+the maximum than @samp{HOST_HOOKS_PCH_MEMORY_ADDRESS} would have
+accepted, return true, otherwise return false.
+
+In addition, free any address space reserved that isn't needed to hold
+@var{size} bytes (whether or not true is returned).  The PCH machinery will
+use @samp{mmap} with @samp{MAP_FIXED} to load the PCH if @samp{HAVE_MMAP_FILE},
+or will use @samp{fread} otherwise.
+
+If no PCH will be loaded, this hook may be called with @var{size}
+zero, in which case all reserved address space should be freed.
+
+Do not try to handle values of @var{address} that could not have been
+returned by this executable; just return false.  Such values usually
+indicate an out-of-date PCH file (built by some other GCC executable),
+and such a PCH file won't work.
+@end deftypefn
+
 @node Filesystem
 @section Host Filesystem
 @cindex configuration file

gcc/ggc-common.c

@@ -29,6 +29,7 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 #include "ggc.h"
 #include "toplev.h"
 #include "params.h"
+#include "hosthooks.h"
 
 #ifdef HAVE_SYS_RESOURCE_H
 # include <sys/resource.h>
@@ -450,19 +451,24 @@ gt_pch_save (FILE *f)
 
   mmi.size = ggc_pch_total_size (state.d);
 
-  /* Try to arrange things so that no relocation is necessary,
+  /* Try to arrange things so that no relocation is necessary, but
-     but don't try very hard.  On most platforms, this will always work,
+     don't try very hard.  On most platforms, this will always work,
-     and on the rest it's a lot of work to do better.  */
+     and on the rest it's a lot of work to do better.  
+     (The extra work goes in HOST_HOOKS_GT_PCH_GET_ADDRESS and
+     HOST_HOOKS_GT_PCH_USE_ADDRESS.)  */
+  mmi.preferred_base = host_hooks.gt_pch_get_address (mmi.size);
+      
 #if HAVE_MMAP_FILE
-  mmi.preferred_base = mmap (NULL, mmi.size,
+  if (mmi.preferred_base == NULL)
-			     PROT_READ | PROT_WRITE, MAP_PRIVATE,
+    {
-			     fileno (state.f), 0);
+      mmi.preferred_base = mmap (NULL, mmi.size,
-  if (mmi.preferred_base == (void *) MAP_FAILED)
+				 PROT_READ | PROT_WRITE, MAP_PRIVATE,
-    mmi.preferred_base = NULL;
+				 fileno (state.f), 0);
-  else
+      if (mmi.preferred_base == (void *) MAP_FAILED)
-    munmap (mmi.preferred_base, mmi.size);
+	mmi.preferred_base = NULL;
-#else /* HAVE_MMAP_FILE */
+      else
-  mmi.preferred_base = NULL;
+	munmap (mmi.preferred_base, mmi.size);
+    }
 #endif /* HAVE_MMAP_FILE */
 
   ggc_pch_this_base (state.d, mmi.preferred_base);
@@ -539,6 +545,7 @@ gt_pch_restore (FILE *f)
   size_t i;
   struct mmap_info mmi;
   void *addr;
+  bool needs_read;
 
   /* Delete any deletable objects.  This makes ggc_pch_read much
      faster, as it can be sure that no GCable objects remain other
@@ -571,47 +578,75 @@ gt_pch_restore (FILE *f)
   if (fread (&mmi, sizeof (mmi), 1, f) != 1)
     fatal_error ("can't read PCH file: %m");
 
-#if HAVE_MMAP_FILE
+  if (host_hooks.gt_pch_use_address (mmi.preferred_base, mmi.size))
-  addr = mmap (mmi.preferred_base, mmi.size,
-	       PROT_READ | PROT_WRITE, MAP_PRIVATE,
-	       fileno (f), mmi.offset);
-
-#if HAVE_MINCORE
-  if (addr != mmi.preferred_base)
     {
-      size_t page_size = getpagesize();
+#if HAVE_MMAP_FILE
-      char one_byte;
+      void *mmap_result;
 
-      if (addr != (void *) MAP_FAILED)
+      mmap_result = mmap (mmi.preferred_base, mmi.size,
-	munmap (addr, mmi.size);
+			  PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_FIXED,
+			  fileno (f), mmi.offset);
 
-      /* We really want to be mapped at mmi.preferred_base
+      /* The file might not be mmap-able.  */
-	 so we're going to resort to MAP_FIXED.  But before,
+      needs_read = mmap_result == MAP_FAILED;
-	 make sure that we can do so without destroying a
-	 previously mapped area, by looping over all pages
-	 that would be affected by the fixed mapping.  */
-      errno = 0;
 
-      for (i = 0; i < mmi.size; i+= page_size)
+      /* Sanity check for broken MAP_FIXED.  */
-	if (mincore ((char *)mmi.preferred_base + i, page_size, (void *)&one_byte) == -1
+      if (! needs_read && mmap_result != mmi.preferred_base)
-	    && errno == ENOMEM)
+	abort ();
-	  continue; /* The page is not mapped.  */
+#else
-	else
+      needs_read = true;
-	  break;
+#endif
-
+      addr = mmi.preferred_base;
-      if (i >= mmi.size)
-	addr = mmap (mmi.preferred_base, mmi.size, 
-		     PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_FIXED,
-		     fileno (f), mmi.offset);
     }
+  else
+    {
+#if HAVE_MMAP_FILE
+      addr = mmap (mmi.preferred_base, mmi.size,
+		   PROT_READ | PROT_WRITE, MAP_PRIVATE,
+		   fileno (f), mmi.offset);
+      
+#if HAVE_MINCORE
+      if (addr != mmi.preferred_base)
+	{
+	  size_t page_size = getpagesize();
+	  char one_byte;
+	  
+	  if (addr != (void *) MAP_FAILED)
+	    munmap (addr, mmi.size);
+	  
+	  /* We really want to be mapped at mmi.preferred_base
+	     so we're going to resort to MAP_FIXED.  But before,
+	     make sure that we can do so without destroying a
+	     previously mapped area, by looping over all pages
+	     that would be affected by the fixed mapping.  */
+	  errno = 0;
+	  
+	  for (i = 0; i < mmi.size; i+= page_size)
+	    if (mincore ((char *)mmi.preferred_base + i, page_size, 
+			 (void *)&one_byte) == -1
+		&& errno == ENOMEM)
+	      continue; /* The page is not mapped.  */
+	    else
+	      break;
+	  
+	  if (i >= mmi.size)
+	    addr = mmap (mmi.preferred_base, mmi.size, 
+			 PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_FIXED,
+			 fileno (f), mmi.offset);
+	}
 #endif /* HAVE_MINCORE */
+      
+      needs_read = addr == (void *) MAP_FAILED;
 
 #else /* HAVE_MMAP_FILE */
-  addr = MAP_FAILED;
+      needs_read = true;
 #endif /* HAVE_MMAP_FILE */
-  if (addr == (void *) MAP_FAILED)
+      if (needs_read)
+	addr = xmalloc (mmi.size);
+    }
+
+  if (needs_read)
     {
-      addr = xmalloc (mmi.size);
       if (fseek (f, mmi.offset, SEEK_SET) != 0
 	  || fread (&mmi, mmi.size, 1, f) != 1)
 	fatal_error ("can't read PCH file: %m");

gcc/hooks.c

@@ -192,3 +192,18 @@ hook_rtx_rtx_null (rtx x ATTRIBUTE_UNUSED)
 {
   return 0;
 }
+
+/* Generic hook that takes a size_t and returns NULL.  */
+void *
+hook_voidp_size_t_null (size_t a ATTRIBUTE_UNUSED)
+{
+  return NULL;
+}
+
+/* Generic hook that takes a size_t and a pointer and returns false.  */
+bool
+hook_bool_voidp_size_t_false (void * a ATTRIBUTE_UNUSED,
+			      size_t b ATTRIBUTE_UNUSED)
+{
+  return false;
+}

gcc/hooks.h

@@ -55,5 +55,7 @@ bool hook_bool_tree_tree_false (tree, tree);
 
 rtx hook_rtx_rtx_identity (rtx);
 rtx hook_rtx_rtx_null (rtx);
+void * hook_voidp_size_t_null (size_t);
+bool hook_bool_voidp_size_t_false (void *, size_t);
 
 #endif

gcc/hosthooks-def.h

@@ -24,10 +24,14 @@ Boston, MA 02111-1307, USA.  */
 #include "hooks.h"
 
 #define HOST_HOOKS_EXTRA_SIGNALS hook_void_void
+#define HOST_HOOKS_GT_PCH_GET_ADDRESS hook_voidp_size_t_null
+#define HOST_HOOKS_GT_PCH_USE_ADDRESS hook_bool_voidp_size_t_false
 
 /* The structure is defined in hosthooks.h.  */
 #define HOST_HOOKS_INITIALIZER {		\
-  HOST_HOOKS_EXTRA_SIGNALS			\
+  HOST_HOOKS_EXTRA_SIGNALS,			\
+  HOST_HOOKS_GT_PCH_GET_ADDRESS,		\
+  HOST_HOOKS_GT_PCH_USE_ADDRESS			\
 }
 
 #endif /* GCC_HOST_HOOKS_DEF_H */

gcc/hosthooks.h

@@ -25,6 +25,9 @@ struct host_hooks
 {
   void (*extra_signals) (void);
 
+  void * (*gt_pch_get_address) (size_t);
+  bool (*gt_pch_use_address) (void *, size_t);
+
   /* Whenever you add entries here, make sure you adjust hosthooks-def.h.  */
 };