GH-131498: Cases generator: Parse down to C statement level. (GH-131948)

* Parse down to statement level in the cases generator

* Add handling for #if macros, treating them much like normal ifs.

Author: markshannon

Lib/test/test_generated_cases.py

@@ -457,7 +457,6 @@ def test_error_if_plain_with_comment(self):
             if (cond) {
                 JUMP_TO_LABEL(label);
             }
-            // Comment is ok
             DISPATCH();
         }
     """
@@ -586,7 +585,6 @@ def test_suppress_dispatch(self):
 
         LABEL(somewhere)
         {
-
         }
     """
         self.run_cases_test(input, output)
@@ -1351,7 +1349,6 @@ def test_pop_on_error_peeks(self):
             }
             // THIRD
             {
-                // Mark j and k as used
                 if (cond) {
                     JUMP_TO_LABEL(pop_2_error);
                 }
@@ -1757,17 +1754,14 @@ def test_complex_label(self):
         output = """
         LABEL(other_label)
         {
-
         }
 
         LABEL(other_label2)
         {
-
         }
 
         LABEL(my_label)
         {
-            // Comment
             _PyFrame_SetStackPointer(frame, stack_pointer);
             do_thing();
             stack_pointer = _PyFrame_GetStackPointer(frame);
@@ -1795,7 +1789,6 @@ def test_spilled_label(self):
         output = """
         LABEL(one)
         {
-            /* STACK SPILLED */
             stack_pointer = _PyFrame_GetStackPointer(frame);
             JUMP_TO_LABEL(two);
         }
@@ -1851,7 +1844,6 @@ def test_multiple_labels(self):
         output = """
         LABEL(my_label_1)
         {
-            // Comment
             _PyFrame_SetStackPointer(frame, stack_pointer);
             do_thing1();
             stack_pointer = _PyFrame_GetStackPointer(frame);
@@ -1860,7 +1852,6 @@ def test_multiple_labels(self):
 
         LABEL(my_label_2)
         {
-            // Comment
             _PyFrame_SetStackPointer(frame, stack_pointer);
             do_thing2();
             stack_pointer = _PyFrame_GetStackPointer(frame);

Python/bytecodes.c

@@ -163,7 +163,7 @@ dummy_func(
         op(_CHECK_PERIODIC_IF_NOT_YIELD_FROM, (--)) {
             if ((oparg & RESUME_OPARG_LOCATION_MASK) < RESUME_AFTER_YIELD_FROM) {
                 _Py_CHECK_EMSCRIPTEN_SIGNALS_PERIODICALLY();
-                QSBR_QUIESCENT_STATE(tstate); \
+                QSBR_QUIESCENT_STATE(tstate);
                 if (_Py_atomic_load_uintptr_relaxed(&tstate->eval_breaker) & _PY_EVAL_EVENTS_MASK) {
                     int err = _Py_HandlePending(tstate);
                     ERROR_IF(err != 0, error);
@@ -2245,7 +2245,8 @@ dummy_func(
             PyObject *attr_o = FT_ATOMIC_LOAD_PTR_ACQUIRE(*value_ptr);
             DEOPT_IF(attr_o == NULL);
             #ifdef Py_GIL_DISABLED
-            if (!_Py_TryIncrefCompareStackRef(value_ptr, attr_o, &attr)) {
+            int increfed = _Py_TryIncrefCompareStackRef(value_ptr, attr_o, &attr);
+            if (!increfed) {
                 DEOPT_IF(true);
             }
             #else
@@ -2322,7 +2323,8 @@ dummy_func(
             }
             STAT_INC(LOAD_ATTR, hit);
 #ifdef Py_GIL_DISABLED
-            if (!_Py_TryIncrefCompareStackRef(&ep->me_value, attr_o, &attr)) {
+            int increfed = _Py_TryIncrefCompareStackRef(&ep->me_value, attr_o, &attr);
+            if (!increfed) {
                 DEOPT_IF(true);
             }
 #else