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.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@69944 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 33 insertions, 0 deletions

diff --git a/gcc/doc/hostconfig.texi b/gcc/doc/hostconfig.texi
index 626a893c167..5c38313efd2 100644
--- a/gcc/doc/hostconfig.texi
+++ b/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