diff options
Diffstat (limited to 'src/alloc.c')
| -rw-r--r-- | src/alloc.c | 29 |
1 files changed, 28 insertions, 1 deletions
diff --git a/src/alloc.c b/src/alloc.c index c4db234aba5..6e4cfa07fa0 100644 --- a/src/alloc.c +++ b/src/alloc.c @@ -1582,6 +1582,21 @@ make_number (EMACS_INT n) } #endif +/* Convert the pointer-sized word P to EMACS_INT while preserving its + type and ptr fields. */ +static Lisp_Object +widen_to_Lisp_Object (void *p) +{ + intptr_t i = (intptr_t) p; +#ifdef USE_LISP_UNION_TYPE + Lisp_Object obj; + obj.i = i; + return obj; +#else + return i; +#endif +} + /*********************************************************************** String Allocation ***********************************************************************/ @@ -4294,7 +4309,19 @@ mark_memory (void *start, void *end) for (pp = start; (void *) pp < end; pp++) for (i = 0; i < sizeof *pp; i += GC_POINTER_ALIGNMENT) - mark_maybe_pointer (*(void **) ((char *) pp + i)); + { + void *w = *(void **) ((char *) pp + i); + mark_maybe_pointer (w); + +#ifdef USE_LSB_TAG + /* A host where a Lisp_Object is wider than a pointer might + allocate a Lisp_Object in non-adjacent halves. If + USE_LSB_TAG, the bottom half is not a valid pointer, so + widen it to to a Lisp_Object and check it that way. */ + if (sizeof w < sizeof (Lisp_Object)) + mark_maybe_object (widen_to_Lisp_Object (w)); +#endif + } } /* setjmp will work with GCC unless NON_SAVING_SETJMP is defined in |