4 files changed, 10 insertions, 5 deletions

diff --git a/src/bytecode.c b/src/bytecode.c
index 6b7e9cbc7b9..8e3cddf7851 100644
--- a/src/bytecode.c
+++ b/src/bytecode.c
@@ -311,6 +311,10 @@ enum byte_code_op
 
 #define TOP (*top)
 
+/* Update the thread's bytecode offset, just before NEXT. */
+
+#define UPDATE_OFFSET (backtrace_byte_offset = pc - bytestr_data)
+
 DEFUN ("byte-code", Fbyte_code, Sbyte_code, 3, 3, 0,
        doc: /* Function used internally in byte-compiled code.
 The first argument, BYTESTR, is a string of byte code;
@@ -424,14 +428,13 @@ 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);
       /* 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 UPDATE_OFFSET; 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.  */
diff --git a/src/eval.c b/src/eval.c
index 5b43b81a6ca..73ad3d3bc90 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -56,8 +56,6 @@ Lisp_Object Vrun_hooks;
 /* FIXME: We should probably get rid of this!  */
 Lisp_Object Vsignaling_function;
 
-int backtrace_byte_offset = -1;
-
 /* These would ordinarily be static, but they need to be visible to GDB.  */
 bool backtrace_p (union specbinding *) EXTERNALLY_VISIBLE;
 Lisp_Object *backtrace_args (union specbinding *) EXTERNALLY_VISIBLE;
diff --git a/src/lisp.h b/src/lisp.h
index ef6302a4670..f413d7a45ec 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -4113,7 +4113,6 @@ extern Lisp_Object Vautoload_queue;
 extern Lisp_Object Vrun_hooks;
 extern Lisp_Object Vsignaling_function;
 extern Lisp_Object inhibit_lisp_code;
-extern int backtrace_byte_offset;
 
 /* To run a normal hook, use the appropriate function from the list below.
    The calling convention:
diff --git a/src/thread.h b/src/thread.h
index a09929fa440..b5e3f0f9c51 100644
--- a/src/thread.h
+++ b/src/thread.h
@@ -103,6 +103,11 @@ struct thread_state
   union specbinding *m_specpdl_ptr;
 #define specpdl_ptr (current_thread->m_specpdl_ptr)
 
+  /* The offset of the current op of the byte-code function being
+     executed. */
+  int m_backtrace_byte_offset;
+#define backtrace_byte_offset (current_thread->m_backtrace_byte_offset)
+
   /* Depth in Lisp evaluations and function calls.  */
   intmax_t m_lisp_eval_depth;
 #define lisp_eval_depth (current_thread->m_lisp_eval_depth)