From 84e8e185cdabbe547cb2b724c2ca1014a73efcfc Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Fri, 7 Oct 2011 09:42:32 -0700 Subject: [PATCH] * alloc.c: Add comment. --- src/alloc.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/src/alloc.c b/src/alloc.c index f4db3abbd93..09ef4b085df 100644 --- a/src/alloc.c +++ b/src/alloc.c @@ -4235,6 +4235,11 @@ mark_maybe_pointer (void *p) } +/* Alignment of Lisp_Object and pointer values. Use offsetof, as it + sometimes returns a smaller alignment than GCC's __alignof__ and + mark_memory might miss objects if __alignof__ were used. For + example, on x86 with WIDE_EMACS_INT, __alignof__ (Lisp_Object) is 8 + but GC_LISP_OBJECT_ALIGNMENT should be 4. */ #ifndef GC_LISP_OBJECT_ALIGNMENT # define GC_LISP_OBJECT_ALIGNMENT offsetof (struct {char a; Lisp_Object b;}, b) #endif -- 2.39.2