gh-128563: Move labels in ceval.c to bytecodes.c (GH-129112)

Author: Fidget-Spinner

Lib/test/test_generated_cases.py

@@ -281,12 +281,12 @@ def run_cases_test(self, input: str, expected: str):
             )
 
         with open(self.temp_output_filename) as temp_output:
-            lines = temp_output.readlines()
-            while lines and lines[0].startswith(("// ", "#", "    #", "\n")):
-                lines.pop(0)
-            while lines and lines[-1].startswith(("#", "\n")):
-                lines.pop(-1)
-        actual = "".join(lines)
+            lines = temp_output.read()
+            _, rest = lines.split(tier1_generator.INSTRUCTION_START_MARKER)
+            instructions, labels_with_prelude_and_postlude = rest.split(tier1_generator.INSTRUCTION_END_MARKER)
+            _, labels_with_postlude = labels_with_prelude_and_postlude.split(tier1_generator.LABEL_START_MARKER)
+            labels, _ = labels_with_postlude.split(tier1_generator.LABEL_END_MARKER)
+            actual = instructions + labels
         # if actual.strip() != expected.strip():
         #     print("Actual:")
         #     print(actual)
@@ -1756,6 +1756,61 @@ def test_kill_in_wrong_order(self):
         with self.assertRaises(SyntaxError):
             self.run_cases_test(input, "")
 
+    def test_complex_label(self):
+        input = """
+        label(my_label) {
+            // Comment
+            do_thing()
+            if (complex) {
+                goto other_label;
+            }
+            goto other_label2;
+        }
+        """
+
+        output = """
+        my_label:
+        {
+            // Comment
+            do_thing()
+            if (complex) {
+                goto other_label;
+            }
+            goto other_label2;
+        }
+        """
+        self.run_cases_test(input, output)
+
+    def test_multiple_labels(self):
+        input = """
+        label(my_label_1) {
+            // Comment
+            do_thing1();
+            goto my_label_2;
+        }
+
+        label(my_label_2) {
+            // Comment
+            do_thing2();
+            goto my_label_3;
+        }
+        """
+
+        output = """
+        my_label_1:
+        {
+            // Comment
+            do_thing1();
+            goto my_label_2;
+        }
+
+        my_label_2:
+        {
+            // Comment
+            do_thing2();
+            goto my_label_3;
+        }
+        """
 
 class TestGeneratedAbstractCases(unittest.TestCase):
     def setUp(self) -> None:

Python/bytecodes.c

@@ -53,6 +53,7 @@
 #define super(name) static int SUPER_##name
 #define family(name, ...) static int family_##name
 #define pseudo(name) static int pseudo_##name
+#define label(name) name:
 
 /* Annotations */
 #define guard
@@ -103,7 +104,6 @@ dummy_func(
     PyObject *codeobj;
     PyObject *cond;
     PyObject *descr;
-    _PyInterpreterFrame  entry_frame;
     PyObject *exc;
     PyObject *exit;
     PyObject *fget;
@@ -5167,6 +5167,125 @@ dummy_func(
             assert(tstate->tracing || eval_breaker == FT_ATOMIC_LOAD_UINTPTR_ACQUIRE(_PyFrame_GetCode(frame)->_co_instrumentation_version));
         }
 
+        label(pop_4_error) {
+            STACK_SHRINK(1);
+            goto pop_3_error;
+        }
+
+        label(pop_3_error) {
+            STACK_SHRINK(1);
+            goto pop_2_error;
+        }
+
+        label(pop_2_error) {
+            STACK_SHRINK(1);
+            goto pop_1_error;
+        }
+
+        label(pop_1_error) {
+            STACK_SHRINK(1);
+            goto error;
+        }
+
+        label(error) {
+            /* Double-check exception status. */
+#ifdef NDEBUG
+            if (!_PyErr_Occurred(tstate)) {
+            _PyErr_SetString(tstate, PyExc_SystemError,
+                             "error return without exception set");
+        }
+#else
+            assert(_PyErr_Occurred(tstate));
+#endif
+
+            /* Log traceback info. */
+            assert(frame->owner != FRAME_OWNED_BY_INTERPRETER);
+            if (!_PyFrame_IsIncomplete(frame)) {
+                PyFrameObject *f = _PyFrame_GetFrameObject(frame);
+                if (f != NULL) {
+                    PyTraceBack_Here(f);
+                }
+            }
+            _PyEval_MonitorRaise(tstate, frame, next_instr-1);
+            goto exception_unwind;
+        }
+
+        label(exception_unwind) {
+            /* We can't use frame->instr_ptr here, as RERAISE may have set it */
+            int offset = INSTR_OFFSET()-1;
+            int level, handler, lasti;
+            if (get_exception_handler(_PyFrame_GetCode(frame), offset, &level, &handler, &lasti) == 0) {
+                // No handlers, so exit.
+                assert(_PyErr_Occurred(tstate));
+
+                /* Pop remaining stack entries. */
+                _PyStackRef *stackbase = _PyFrame_Stackbase(frame);
+                while (stack_pointer > stackbase) {
+                    PyStackRef_XCLOSE(POP());
+                }
+                assert(STACK_LEVEL() == 0);
+                _PyFrame_SetStackPointer(frame, stack_pointer);
+                monitor_unwind(tstate, frame, next_instr-1);
+                goto exit_unwind;
+            }
+
+            assert(STACK_LEVEL() >= level);
+            _PyStackRef *new_top = _PyFrame_Stackbase(frame) + level;
+            while (stack_pointer > new_top) {
+                PyStackRef_XCLOSE(POP());
+            }
+            if (lasti) {
+                int frame_lasti = _PyInterpreterFrame_LASTI(frame);
+                PyObject *lasti = PyLong_FromLong(frame_lasti);
+                if (lasti == NULL) {
+                    goto exception_unwind;
+                }
+                PUSH(PyStackRef_FromPyObjectSteal(lasti));
+            }
+
+            /* Make the raw exception data
+                available to the handler,
+                so a program can emulate the
+                Python main loop. */
+            PyObject *exc = _PyErr_GetRaisedException(tstate);
+            PUSH(PyStackRef_FromPyObjectSteal(exc));
+            next_instr = _PyFrame_GetBytecode(frame) + handler;
+
+            if (monitor_handled(tstate, frame, next_instr, exc) < 0) {
+                goto exception_unwind;
+            }
+            /* Resume normal execution */
+#ifdef LLTRACE
+            if (frame->lltrace >= 5) {
+                lltrace_resume_frame(frame);
+            }
+#endif
+            DISPATCH();
+        }
+
+        label(exit_unwind) {
+            assert(_PyErr_Occurred(tstate));
+            _Py_LeaveRecursiveCallPy(tstate);
+            assert(frame->owner != FRAME_OWNED_BY_INTERPRETER);
+            // GH-99729: We need to unlink the frame *before* clearing it:
+            _PyInterpreterFrame *dying = frame;
+            frame = tstate->current_frame = dying->previous;
+            _PyEval_FrameClearAndPop(tstate, dying);
+            frame->return_offset = 0;
+            if (frame->owner == FRAME_OWNED_BY_INTERPRETER) {
+                /* Restore previous frame and exit */
+                tstate->current_frame = frame->previous;
+                tstate->c_recursion_remaining += PY_EVAL_C_STACK_UNITS;
+                return NULL;
+            }
+            goto resume_with_error;
+        }
+
+        label(resume_with_error) {
+            next_instr = frame->instr_ptr;
+            stack_pointer = _PyFrame_GetStackPointer(frame);
+            goto error;
+        }
 // END BYTECODES //
 
     }

Python/ceval.c

@@ -882,143 +882,9 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, _PyInterpreterFrame *frame, int
 
     DISPATCH();
 
-    {
-    /* Start instructions */
-#if !USE_COMPUTED_GOTOS
-    dispatch_opcode:
-        switch (opcode)
-#endif
-        {
-
 #include "generated_cases.c.h"
 
 
-#if USE_COMPUTED_GOTOS
-        _unknown_opcode:
-#else
-        EXTRA_CASES  // From pycore_opcode_metadata.h, a 'case' for each unused opcode
-#endif
-            /* Tell C compilers not to hold the opcode variable in the loop.
-               next_instr points the current instruction without TARGET(). */
-            opcode = next_instr->op.code;
-            _PyErr_Format(tstate, PyExc_SystemError,
-                          "%U:%d: unknown opcode %d",
-                          _PyFrame_GetCode(frame)->co_filename,
-                          PyUnstable_InterpreterFrame_GetLine(frame),
-                          opcode);
-            goto error;
-
-        } /* End instructions */
-
-        /* This should never be reached. Every opcode should end with DISPATCH()
-           or goto error. */
-        Py_UNREACHABLE();
-
-pop_4_error:
-    STACK_SHRINK(1);
-pop_3_error:
-    STACK_SHRINK(1);
-pop_2_error:
-    STACK_SHRINK(1);
-pop_1_error:
-    STACK_SHRINK(1);
-error:
-        /* Double-check exception status. */
-#ifdef NDEBUG
-        if (!_PyErr_Occurred(tstate)) {
-            _PyErr_SetString(tstate, PyExc_SystemError,
-                             "error return without exception set");
-        }
-#else
-        assert(_PyErr_Occurred(tstate));
-#endif
-
-        /* Log traceback info. */
-        assert(frame != &entry_frame);
-        if (!_PyFrame_IsIncomplete(frame)) {
-            PyFrameObject *f = _PyFrame_GetFrameObject(frame);
-            if (f != NULL) {
-                PyTraceBack_Here(f);
-            }
-        }
-        _PyEval_MonitorRaise(tstate, frame, next_instr-1);
-exception_unwind:
-        {
-            /* We can't use frame->instr_ptr here, as RERAISE may have set it */
-            int offset = INSTR_OFFSET()-1;
-            int level, handler, lasti;
-            if (get_exception_handler(_PyFrame_GetCode(frame), offset, &level, &handler, &lasti) == 0) {
-                // No handlers, so exit.
-                assert(_PyErr_Occurred(tstate));
-
-                /* Pop remaining stack entries. */
-                _PyStackRef *stackbase = _PyFrame_Stackbase(frame);
-                while (stack_pointer > stackbase) {
-                    PyStackRef_XCLOSE(POP());
-                }
-                assert(STACK_LEVEL() == 0);
-                _PyFrame_SetStackPointer(frame, stack_pointer);
-                monitor_unwind(tstate, frame, next_instr-1);
-                goto exit_unwind;
-            }
-
-            assert(STACK_LEVEL() >= level);
-            _PyStackRef *new_top = _PyFrame_Stackbase(frame) + level;
-            while (stack_pointer > new_top) {
-                PyStackRef_XCLOSE(POP());
-            }
-            if (lasti) {
-                int frame_lasti = _PyInterpreterFrame_LASTI(frame);
-                PyObject *lasti = PyLong_FromLong(frame_lasti);
-                if (lasti == NULL) {
-                    goto exception_unwind;
-                }
-                PUSH(PyStackRef_FromPyObjectSteal(lasti));
-            }
-
-            /* Make the raw exception data
-                available to the handler,
-                so a program can emulate the
-                Python main loop. */
-            PyObject *exc = _PyErr_GetRaisedException(tstate);
-            PUSH(PyStackRef_FromPyObjectSteal(exc));
-            next_instr = _PyFrame_GetBytecode(frame) + handler;
-
-            if (monitor_handled(tstate, frame, next_instr, exc) < 0) {
-                goto exception_unwind;
-            }
-            /* Resume normal execution */
-#ifdef LLTRACE
-            if (frame->lltrace >= 5) {
-                lltrace_resume_frame(frame);
-            }
-#endif
-            DISPATCH();
-        }
-    }
-
-exit_unwind:
-    assert(_PyErr_Occurred(tstate));
-    _Py_LeaveRecursiveCallPy(tstate);
-    assert(frame != &entry_frame);
-    // GH-99729: We need to unlink the frame *before* clearing it:
-    _PyInterpreterFrame *dying = frame;
-    frame = tstate->current_frame = dying->previous;
-    _PyEval_FrameClearAndPop(tstate, dying);
-    frame->return_offset = 0;
-    if (frame == &entry_frame) {
-        /* Restore previous frame and exit */
-        tstate->current_frame = frame->previous;
-        tstate->c_recursion_remaining += PY_EVAL_C_STACK_UNITS;
-        return NULL;
-    }
-
-resume_with_error:
-    next_instr = frame->instr_ptr;
-    stack_pointer = _PyFrame_GetStackPointer(frame);
-    goto error;
-
-
 #ifdef _Py_TIER2
 
 // Tier 2 is also here!