Add macros to allocate temporary Lisp objects with alloca.

Respect MAX_ALLOCA and fall back to regular GC for large objects.
* character.h (parse_str_as_multibyte): Move prototype to ...
* lisp.h (parse_str_as_multibyte): ... here.
(struct Lisp_Cons): Add GCALIGNED attribute if supported.
(scoped_cons, scoped_list2, build_local_vector, build_local_string):
New macros.
(scoped_cons_init, pointer_valid_for_lisp_object, local_vector_init)
(local_string_init): New functions.
* alloc.c (verify_alloca) [ENABLE_CHECKING]: New function.
(init_alloc_once): Call it.

1 files changed, 12 insertions, 0 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index a01c753161c..d1e8314b172 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -5,6 +5,18 @@
         (x_delete_terminal): Do not close X connection fd (Bug#18403).
         Add eassert and mark dpyinfo as dead only if it was alive.
 
+        Add macros to allocate temporary Lisp objects with alloca.
+        Respect MAX_ALLOCA and fall back to regular GC for large objects.
+        * character.h (parse_str_as_multibyte): Move prototype to ...
+        * lisp.h (parse_str_as_multibyte): ... here.
+        (struct Lisp_Cons): Add GCALIGNED attribute if supported.
+        (scoped_cons, scoped_list2, build_local_vector, build_local_string):
+        New macros.
+        (scoped_cons_init, pointer_valid_for_lisp_object, local_vector_init)
+        (local_string_init): New functions.
+        * alloc.c (verify_alloca) [ENABLE_CHECKING]: New function.
+        (init_alloc_once): Call it.
+
 2014-09-08  Eli Zaretskii  <eliz@gnu.org>
 
         * dispnew.c (prepare_desired_row): When MODE_LINE_P is zero,