* lisp.h (make_uninit_vector): New function.

[bpt/emacs.git] / src / lisp.h

diff --git a/src/lisp.h b/src/lisp.h
index 251b5e0..c15e83b 100644 (file)
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -3043,6 +3043,27 @@ extern void make_byte_code (struct Lisp_Vector *);
 extern Lisp_Object Qautomatic_gc;
 extern Lisp_Object Qchar_table_extra_slots;
 extern struct Lisp_Vector *allocate_vector (EMACS_INT);
+
+/* Make an unitialized vector for SIZE objects.  NOTE: you must
+   be sure that GC cannot happen until the vector is completely
+   initialized.  E.g. the following code is likely to crash:
+
+   v = make_uninit_vector (3);
+   ASET (v, 0, obj0);
+   ASET (v, 1, Ffunction_can_gc ());
+   ASET (v, 2, obj1);  */
+
+LISP_INLINE Lisp_Object
+make_uninit_vector (ptrdiff_t size)
+{
+  Lisp_Object v;
+  struct Lisp_Vector *p;
+
+  p = allocate_vector (size);
+  XSETVECTOR (v, p);
+  return v;
+}
+
 extern struct Lisp_Vector *allocate_pseudovector (int, int, enum pvec_type);
 #define ALLOCATE_PSEUDOVECTOR(typ,field,tag)                           \
   ((typ*)                                                              \