Store bytecode offset within exec_byte_code

* src/bytecode.c (exec_byte_code): Store offset in the backtrace frame
for the function being executed, before calling Ffuncall.

* src/eval.c (record_in_backtrace): Don't record the offset.
(backtrace_next, backtrace_top): Move declarations to lisp.h.

* src/lisp.h (backtrace_next, backtrace_top): Declare.

1 files changed, 8 insertions, 3 deletions

diff --git a/src/bytecode.c b/src/bytecode.c
index 6b7e9cbc7b9..f4900fc588f 100644
--- a/src/bytecode.c
+++ b/src/bytecode.c
@@ -378,6 +378,8 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
   memcpy (bytestr_data, SDATA (bytestr), bytestr_length);
   unsigned char const *pc = bytestr_data;
   ptrdiff_t count = SPECPDL_INDEX ();
+  union specbinding *bt_frame = specpdl_ptr;
+  bt_frame = backtrace_next (bt_frame);
 
   if (!NILP (args_template))
     {
@@ -424,14 +426,16 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
          Threading provides a performance boost.  These macros are how
          we allow the code to be compiled both ways.  */
 #ifdef BYTE_CODE_THREADED
-#define UPDATE_OFFSET (backtrace_byte_offset = pc - bytestr_data);
+#define UPDATE_OFFSET(to)                                       \
+      if (bt_frame->kind == SPECPDL_BACKTRACE)                  \
+        bt_frame->bt.bytecode_offset = (to);
       /* The CASE macro introduces an instruction's body.  It is
          either a label or a case label.  */
 #define CASE(OP) insn_ ## OP
       /* NEXT is invoked at the end of an instruction to go to the
          next instruction.  It is either a computed goto, or a
          plain break.  */
-#define NEXT UPDATE_OFFSET goto *(targets[op = FETCH])
+#define NEXT goto *(targets[op = FETCH])
       /* FIRST is like NEXT, but is only used at the start of the
          interpreter body.  In the switch-based interpreter it is the
          switch, so the threaded definition must include a semicolon.  */
@@ -633,6 +637,7 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
                   }
               }
 #endif
+            UPDATE_OFFSET(pc - bytestr_data);
             TOP = Ffuncall (op + 1, &TOP);
             NEXT;
           }
@@ -1449,7 +1454,7 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
         unbind_to (count, Qnil);
       error ("binding stack not balanced (serious byte compiler bug)");
     }
-  backtrace_byte_offset = -1;
+  UPDATE_OFFSET(-1);
   Lisp_Object result = TOP;
   SAFE_FREE ();
   return result;