Use functions and constants to manipulate Lisp_Save_Value objects.

This replaces code that used macros and strings and token-pasting.
The change makes the C source a bit easier to follow,
and shrinks the Emacs executable a bit.
* alloc.c: Verify some properties of Lisp_Save_Value's representation.
(make_save_value): Change 1st arg from string to enum.  All callers
changed.
(INTX): Remove.
(mark_object): Use if, not #if, for GC_MARK_STACK.
* lisp.h (SAVE_VALUEP, XSAVE_VALUE, XSAVE_POINTER, XSAVE_INTEGER)
(XSAVE_OBJECT): Now functions, not macros.
(STRING_BYTES_BOUND): Now just a macro, not a constant too;
the constant was never used.
(SAVE_SLOT_BITS, SAVE_VALUE_SLOTS, SAVE_TYPE_BITS, SAVE_TYPE_INT_INT)
(SAVE_TYPE_INT_INT_INT, SAVE_TYPE_OBJ_OBJ, SAVE_TYPE_OBJ_OBJ_OBJ)
(SAVE_TYPE_OBJ_OBJ_OBJ_OBJ, SAVE_TYPE_PTR_INT, SAVE_TYPE_PTR_OBJ)
(SAVE_TYPE_PTR_PTR, SAVE_TYPE_PTR_PTR_OBJ, SAVE_TYPE_MEMORY):
New constants.
(struct Lisp_Save_Value): Replace members area, type0, type1, type2,
type3 with a single member save_type.  All uses changed.
(save_type, set_save_pointer, set_save_integer): New functions.
* print.c (PRINTX): Remove.

1 files changed, 40 insertions, 55 deletions

diff --git a/src/alloc.c b/src/alloc.c
index 39379bc3bd7..4245b3069fa 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -3326,56 +3326,50 @@ free_misc (Lisp_Object misc)
   total_free_markers++;
 }
 
+/* Verify properties of Lisp_Save_Value's representation
+   that are assumed here and elsewhere.  */
+
+verify (SAVE_UNUSED == 0);
+verify ((SAVE_INTEGER | SAVE_POINTER | SAVE_OBJECT) >> SAVE_SLOT_BITS == 0);
+
 /* Return a Lisp_Save_Value object with the data saved according to
-   FMT.  Format specifiers are `i' for an integer, `p' for a pointer
-   and `o' for Lisp_Object.  Up to 4 objects can be specified.  */
+   DATA_TYPE.  DATA_TYPE should be one of SAVE_TYPE_INT_INT, etc.  */
 
 Lisp_Object
-make_save_value (const char *fmt, ...)
+make_save_value (enum Lisp_Save_Type save_type, ...)
 {
   va_list ap;
-  int len = strlen (fmt);
+  int i;
   Lisp_Object val = allocate_misc (Lisp_Misc_Save_Value);
   struct Lisp_Save_Value *p = XSAVE_VALUE (val);
 
-  eassert (0 < len && len < 5);
-  va_start (ap, fmt);
-
-#define INITX(index)                                           \
-  do {                                                         \
-    if (len <= index)                                          \
-      p->type ## index = SAVE_UNUSED;                          \
-    else                                                       \
-      {                                                        \
-        if (fmt[index] == 'i')                                 \
-         {                                                     \
-           p->type ## index = SAVE_INTEGER;                    \
-           p->data[index].integer = va_arg (ap, ptrdiff_t);    \
-         }                                                     \
-       else if (fmt[index] == 'p')                             \
-         {                                                     \
-           p->type ## index = SAVE_POINTER;                    \
-           p->data[index].pointer = va_arg (ap, void *);       \
-         }                                                     \
-       else if (fmt[index] == 'o')                             \
-         {                                                     \
-           p->type ## index = SAVE_OBJECT;                     \
-           p->data[index].object = va_arg (ap, Lisp_Object);   \
-         }                                                     \
-       else                                                    \
-         emacs_abort ();                                       \
-      }                                                        \
-  } while (0)
+  eassert (0 < save_type
+           && (save_type < 1 << (SAVE_TYPE_BITS - 1)
+               || save_type == SAVE_TYPE_MEMORY));
+  p->save_type = save_type;
+  va_start (ap, save_type);
+  save_type &= ~ (1 << (SAVE_TYPE_BITS - 1));
+
+  for (i = 0; save_type; i++, save_type >>= SAVE_SLOT_BITS)
+    switch (save_type & ((1 << SAVE_SLOT_BITS) - 1))
+      {
+      case SAVE_POINTER:
+        p->data[i].pointer = va_arg (ap, void *);
+        break;
 
-  INITX (0);
-  INITX (1);
-  INITX (2);
-  INITX (3);
+      case SAVE_INTEGER:
+        p->data[i].integer = va_arg (ap, ptrdiff_t);
+        break;
 
-#undef INITX
+      case SAVE_OBJECT:
+        p->data[i].object = va_arg (ap, Lisp_Object);
+        break;
+
+      default:
+        emacs_abort ();
+      }
 
   va_end (ap);
-  p->area = 0;
   return val;
 }
 
@@ -3386,11 +3380,8 @@ make_save_pointer (void *pointer)
 {
   Lisp_Object val = allocate_misc (Lisp_Misc_Save_Value);
   struct Lisp_Save_Value *p = XSAVE_VALUE (val);
-
-  p->area = 0;
-  p->type0 = SAVE_POINTER;
+  p->save_type = SAVE_POINTER;
   p->data[0].pointer = pointer;
-  p->type1 = p->type2 = p->type3 = SAVE_UNUSED;
   return val;
 }
 
@@ -5958,12 +5949,11 @@ mark_object (Lisp_Object arg)
         case Lisp_Misc_Save_Value:
           XMISCANY (obj)->gcmarkbit = 1;
           {
-            register struct Lisp_Save_Value *ptr = XSAVE_VALUE (obj);
-            /* If `area' is nonzero, `data[0].pointer' is the address
+            struct Lisp_Save_Value *ptr = XSAVE_VALUE (obj);
+            /* If `save_type' is zero, `data[0].pointer' is the address
                of a memory area containing `data[1].integer' potential
                Lisp_Objects.  */
-#if GC_MARK_STACK
-            if (ptr->area)
+            if (GC_MARK_STACK && ptr->save_type == SAVE_TYPE_MEMORY)
               {
                 Lisp_Object *p = ptr->data[0].pointer;
                 ptrdiff_t nelt;
@@ -5971,17 +5961,12 @@ mark_object (Lisp_Object arg)
                   mark_maybe_object (*p);
               }
             else
-#endif /* GC_MARK_STACK */
               {
                 /* Find Lisp_Objects in `data[N]' slots and mark them.  */
-                if (ptr->type0 == SAVE_OBJECT)
-                  mark_object (ptr->data[0].object);
-                if (ptr->type1 == SAVE_OBJECT)
-                  mark_object (ptr->data[1].object);
-                if (ptr->type2 == SAVE_OBJECT)
-                  mark_object (ptr->data[2].object);
-                if (ptr->type3 == SAVE_OBJECT)
-                  mark_object (ptr->data[3].object);
+                int i;
+                for (i = 0; i < SAVE_VALUE_SLOTS; i++)
+                  if (save_type (ptr, i) == SAVE_OBJECT)
+                    mark_object (ptr->data[i].object);
               }
           }
           break;