use RESUME oparg to store exception depth info

python · iritkatriel · Nov 2, 2023 · Oct 26, 2023 · Oct 26, 2023 · Oct 26, 2023
commit 219e6c136ff70382fe643664b071ac4c6d8c0849
diff --git a/Include/internal/pycore_opcode_utils.h b/Include/internal/pycore_opcode_utils.h
@@ -61,8 +61,9 @@ extern "C" {
 /* Values used in the oparg for RESUME */
 #define RESUME_AT_FUNC_START 0
 #define RESUME_AFTER_YIELD 1
-#define RESUME_AFTER_YIELD_FROM 2
-#define RESUME_AFTER_AWAIT 3
+#define RESUME_AFTER_YIELD_EXC_DEPTH_1 2
+#define RESUME_AFTER_YIELD_FROM 3
+#define RESUME_AFTER_AWAIT 4
 
 
 #ifdef __cplusplus

@@ -459,6 +459,7 @@ def _write_atomic(path, data, mode=0o666):
 #     Python 3.13a1 3561 (Add cache entry to branch instructions)
 #     Python 3.13a1 3562 (Assign opcode IDs for internal ops in separate range)
 #     Python 3.13a1 3563 (Add CALL_KW and remove KW_NAMES)
+#     Python 3.13a1 3564 (Shifted some of the oparg values of RESUME to add a new one)
 
 #     Python 3.14 will start with 3600
 
@@ -475,7 +476,7 @@ def _write_atomic(path, data, mode=0o666):
 # Whenever MAGIC_NUMBER is changed, the ranges in the magic_values array
 # in PC/launcher.c must also be updated.
 
-MAGIC_NUMBER = (3563).to_bytes(2, 'little') + b'\r\n'
+MAGIC_NUMBER = (3564).to_bytes(2, 'little') + b'\r\n'
 
 _RAW_MAGIC_NUMBER = int.from_bytes(MAGIC_NUMBER, 'little')  # For import.c
 

diff --git a/Lib/test/test_dis.py b/Lib/test/test_dis.py
@@ -533,7 +533,7 @@ async def _asyncwith(c):
             LOAD_CONST               0 (None)
          >> SEND                     3 (to 24)
             YIELD_VALUE              2
-            RESUME                   3
+            RESUME                   4
             JUMP_BACKWARD_NO_INTERRUPT 5 (to 14)
          >> END_SEND
             POP_TOP
@@ -549,7 +549,7 @@ async def _asyncwith(c):
             LOAD_CONST               0 (None)
          >> SEND                     3 (to 60)
             YIELD_VALUE              2
-            RESUME                   3
+            RESUME                   4
             JUMP_BACKWARD_NO_INTERRUPT 5 (to 50)
          >> END_SEND
             POP_TOP
@@ -572,7 +572,7 @@ async def _asyncwith(c):
             LOAD_CONST               0 (None)
          >> SEND                     4 (to 102)
             YIELD_VALUE              3
-            RESUME                   3
+            RESUME                   4
             JUMP_BACKWARD_NO_INTERRUPT 5 (to 90)
          >> CLEANUP_THROW
          >> END_SEND
@@ -763,7 +763,7 @@ def foo(x):
             LOAD_FAST                1 (z)
             BINARY_OP                0 (+)
             YIELD_VALUE              1
-            RESUME                   1
+            RESUME                   2
             POP_TOP
             JUMP_BACKWARD           12 (to 10)
          >> END_FOR

@@ -343,12 +343,6 @@ is_resume(_Py_CODEUNIT *instr)
     );
 }
 
-static inline bool
-is_yield(_Py_CODEUNIT *instr)
-{
-    return instr->op.code == YIELD_VALUE || instr->op.code == INSTRUMENTED_YIELD_VALUE;
-}
-
 PyObject *
 _PyGen_yf(PyGenObject *gen)
 {
@@ -397,19 +391,11 @@ gen_close(PyGenObject *gen, PyObject *args)
         Py_DECREF(yf);
     }
     _PyInterpreterFrame *frame = (_PyInterpreterFrame *)gen->gi_iframe;
-    /* It is possible for the previous instruction to not be a
-     * YIELD_VALUE if the debugger has changed the lineno. */
-    assert(_PyOpcode_Caches[YIELD_VALUE] == 0);
-    assert(_PyOpcode_Caches[INSTRUMENTED_YIELD_VALUE] == 0);
-    if (err == 0 && is_yield(frame->instr_ptr - 1)) {
-        _Py_CODEUNIT *yield_instr = frame->instr_ptr - 1;
-        assert(is_resume(frame->instr_ptr));
-        int exception_handler_depth = yield_instr->op.arg;
-        assert(exception_handler_depth > 0);
+    if (is_resume(frame->instr_ptr)) {
         /* We can safely ignore the outermost try block
-         * as it automatically generated to handle
+         * as it is automatically generated to handle
          * StopIteration. */
-        if (exception_handler_depth == 1) {
+        if (frame->instr_ptr->op.arg == RESUME_AFTER_YIELD_EXC_DEPTH_1) {
             gen->gi_frame_state = FRAME_COMPLETED;
             Py_RETURN_NONE;
         }

@@ -882,6 +882,12 @@ label_exception_targets(basicblock *entryblock) {
                 if (instr->i_opcode == YIELD_VALUE) {
                     instr->i_oparg = except_stack->depth;
                 }
+                if (instr->i_opcode == RESUME &&
+                    instr->i_oparg == RESUME_AFTER_YIELD &&
+                    except_stack->depth == 1)
+                {
+                    instr->i_oparg = RESUME_AFTER_YIELD_EXC_DEPTH_1;
+                }
                 instr->i_except = handler;
             }
         }