GH-122155: Track local variables between pops and pushes in cases generator

Lib/test/test_generated_cases.py

@@ -31,7 +31,7 @@ def skip_if_different_mount_drives():
 with test_tools.imports_under_tool("cases_generator"):
  from analyzer import StackItem
  import parser
- from stack import Stack
+ from stack import Local, Stack
  import tier1_generator
  import optimizer_generator
 
@@ -60,9 +60,9 @@ def test_effect_sizes(self):
  stack.pop(y)
  stack.pop(x)
  for out in outputs:
- stack.push(out)
- self.assertEqual(stack.base_offset.to_c(), "-1 - oparg*2 - oparg")
- self.assertEqual(stack.top_offset.to_c(), "1 - oparg*2 - oparg + oparg*4")
+ stack.push(Local.local(out))
+ self.assertEqual(stack.base_offset.to_c(), "-1 - oparg - oparg*2")
+ self.assertEqual(stack.top_offset.to_c(), "1 - oparg - oparg*2 + oparg*4")
 
 
 class TestGeneratedCases(unittest.TestCase):
@@ -602,7 +602,11 @@ def test_array_error_if(self):
  frame->instr_ptr = next_instr;
  next_instr += 1;
  INSTRUCTION_STATS(OP);
- if (oparg == 0){stack_pointer += -1 - oparg; goto somewhere}
+ if (oparg == 0){
+ stack_pointer += -1 - oparg;
+ assert(WITHIN_STACK_BOUNDS());
+ goto somewhere;
+ }
  stack_pointer += -1 - oparg;
  assert(WITHIN_STACK_BOUNDS());
  DISPATCH();
@@ -908,19 +912,17 @@ def test_used_unused_used(self):
  next_instr += 1;
  INSTRUCTION_STATS(TEST);
  _PyStackRef w;
- _PyStackRef x;
  _PyStackRef y;
  // FIRST
  w = stack_pointer[-1];
 {
  use(w);
  }
  // SECOND
- x = w;
 {
  }
  // THIRD
- y = x;
+ y = w;
 {
  use(y);
  }
@@ -1024,6 +1026,7 @@ def test_pop_on_error_peeks(self):
  }
 
  op(THIRD, (j, k --)){
+ j,k; // Mark j and k as used
  ERROR_IF(cond, error);
  }
 
@@ -1054,6 +1057,7 @@ def test_pop_on_error_peeks(self):
  k = b;
  j = a;
 {
+ j,k; // Mark j and k as used
  if (cond) goto pop_2_error;
  }
  stack_pointer += -2;
@@ -1063,6 +1067,51 @@ def test_pop_on_error_peeks(self):
  """
  self.run_cases_test(input, output)
 
+ def test_push_then_error(self):
+
+ input = """
+ op(FIRST, ( -- a)){
+ a = 1;
+ }
+
+ op(SECOND, (a -- a, b)){
+ b = 1;
+ ERROR_IF(cond, error);
+ }
+
+ macro(TEST) = FIRST + SECOND;
+ """
+
+ output = """
+ TARGET(TEST){
+ frame->instr_ptr = next_instr;
+ next_instr += 1;
+ INSTRUCTION_STATS(TEST);
+ _PyStackRef a;
+ _PyStackRef b;
+ // FIRST
+{
+ a = 1;
+ }
+ // SECOND
+{
+ b = 1;
+ if (cond){
+ stack_pointer[0] = a;
+ stack_pointer += 1;
+ assert(WITHIN_STACK_BOUNDS());
+ goto error;
+ }
+ }
+ stack_pointer[0] = a;
+ stack_pointer[1] = b;
+ stack_pointer += 2;
+ assert(WITHIN_STACK_BOUNDS());
+ DISPATCH();
+ }
+ """
+ self.run_cases_test(input, output)
+
 
 class TestGeneratedAbstractCases(unittest.TestCase):
  def setUp(self) -> None:

Python/bytecodes.c

@@ -1357,8 +1357,8 @@ dummy_func(
  (void)counter;
  }
 
- op(_UNPACK_SEQUENCE, (seq -- unused[oparg])){
- _PyStackRef *top = stack_pointer + oparg - 1;
+ op(_UNPACK_SEQUENCE, (seq -- output[oparg])){
+ _PyStackRef *top = output + oparg;
  int res = _PyEval_UnpackIterableStackRef(tstate, seq, oparg, -1, top);
  DECREF_INPUTS();
  ERROR_IF(res == 0, error);
@@ -1401,9 +1401,8 @@ dummy_func(
  DECREF_INPUTS();
  }
 
- inst(UNPACK_EX, (seq -- unused[oparg & 0xFF], unused, unused[oparg >> 8])){
- int totalargs = 1 + (oparg & 0xFF) + (oparg >> 8);
- _PyStackRef *top = stack_pointer + totalargs - 1;
+ inst(UNPACK_EX, (seq -- left[oparg & 0xFF], unused, right[oparg >> 8])){
+ _PyStackRef *top = right + (oparg >> 8);
  int res = _PyEval_UnpackIterableStackRef(tstate, seq, oparg & 0xFF, oparg >> 8, top);
  DECREF_INPUTS();
  ERROR_IF(res == 0, error);