add finalizers to ggc

This implements finalizers by keeping a list of registered finalizers
and after every mark but before sweeping check to see if any of them are
for unmarked blocks.

gcc/ChangeLog:

	* ggc-common.c (ggc_internal_cleared_alloc): Adjust.
	* ggc-none.c (ggc_internal_alloc): Assert if a finalizer is passed.
	(ggc_internal_cleared_alloc): Likewise.
	* ggc-page.c (finalizer): New class.
(vec_finalizer): Likewise.
	(globals::finalizers): New member.
(globals::vec_finalizers): Likewise.
	(ggc_internal_alloc): Record the finalizer if any for the block being
	allocated.
	(ggc_handle_finalizers): New function.
	(ggc_collect): Call ggc_handle_finalizers.
	* ggc.h (ggc_internal_alloc): Add arguments to allow installing a
	finalizer.
	(ggc_internal_cleared_alloc): Likewise.
	(finalize): New function.
	(need_finalization_p): Likewise.
	(ggc_alloc): Install the type's destructor as the finalizer if it
	might do something.
	(ggc_cleared_alloc): Likewise.
	(ggc_vec_alloc): Likewise.
	(ggc_cleared_vec_alloc): Likewise.

From-SVN: r210568

1 files changed, 6 insertions, 2 deletions

diff --git a/gcc/ggc-none.c b/gcc/ggc-none.c
index aad89bf..97d3566 100644
--- a/gcc/ggc-none.c
+++ b/gcc/ggc-none.c
@@ -41,14 +41,18 @@ ggc_round_alloc_size (size_t requested_size)
 }
 
 void *
-ggc_internal_alloc (size_t size MEM_STAT_DECL)
+ggc_internal_alloc (size_t size, void (*f)(void *), size_t, size_t
+		    MEM_STAT_DECL)
 {
+  gcc_assert (!f); // ggc-none doesn't support finalizers
   return xmalloc (size);
 }
 
 void *
-ggc_internal_cleared_alloc (size_t size MEM_STAT_DECL)
+ggc_internal_cleared_alloc (size_t size, void (*f)(void *), size_t, size_t
+			    MEM_STAT_DECL)
 {
+  gcc_assert (!f); // ggc-none doesn't support finalizers
   return xcalloc (size, 1);
 }