gh-94485: Set line number of module's RESUME instruction to 0, as specified by PEP 626

Lib/importlib/_bootstrap_external.py

@@ -410,6 +410,7 @@ def _write_atomic(path, data, mode=0o666):
 # Python 3.12a1 3504 (Merge LOAD_METHOD back into LOAD_ATTR)
 # Python 3.12a1 3505 (Specialization/Cache for FOR_ITER)
 # Python 3.12a1 3506 (Add BINARY_SLICE and STORE_SLICE instructions)
+# Python 3.12a1 3507 (Set lineno of module's RESUME to 0)
 
 # Python 3.13 will start with 3550
 
@@ -423,7 +424,7 @@ 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 = (3506).to_bytes(2, 'little') + b'\r\n'
+MAGIC_NUMBER = (3507).to_bytes(2, 'little') + b'\r\n'
 
 _RAW_MAGIC_NUMBER = int.from_bytes(MAGIC_NUMBER, 'little') # For import.c
 

Lib/test/test_code.py

@@ -376,7 +376,6 @@ def test_co_positions_artificial_instructions(self):
  for instruction in artificial_instructions
  ],
  [
- ('RESUME', 0),
  ("PUSH_EXC_INFO", None),
  ("LOAD_CONST", None), # artificial 'None'
  ("STORE_NAME", "e"), # XX: we know the location for this

Lib/test/test_compile.py

@@ -161,7 +161,7 @@ def test_leading_newlines(self):
  co = compile(s256, 'fn', 'exec')
  self.assertEqual(co.co_firstlineno, 1)
  lines = list(co.co_lines())
- self.assertEqual(lines[0][2], None)
+ self.assertEqual(lines[0][2], 0)
  self.assertEqual(lines[1][2], 257)
 
  def test_literals_with_leading_zeroes(self):
@@ -1032,8 +1032,8 @@ def test_uses_slice_instructions(self):
  def check_op_count(func, op, expected):
  actual = 0
  for instr in dis.Bytecode(func):
-  if instr.opname == op:
-  actual += 1
+ if instr.opname == op:
+ actual += 1
  self.assertEqual(actual, expected)
 
  def load():
@@ -1090,6 +1090,8 @@ def generic_visit(self, node):
 
  # Check against the positions in the code object.
  for (line, end_line, col, end_col) in code.co_positions():
+ if line == 0:
+ continue # This is an artificial module-start line
  # If the offset is not None (indicating missing data), ensure that
  # it was part of one of the AST nodes.
  if line is not None:

Lib/test/test_dis.py

@@ -267,7 +267,7 @@ def bug42562():
 expr_str = "x + 1"
 
 dis_expr_str = """\
-   RESUME 0
+ 0 RESUME 0
 
  1 LOAD_NAME 0 (x)
  LOAD_CONST 0 (1)
@@ -278,7 +278,7 @@ def bug42562():
 simple_stmt_str = "x = x + 1"
 
 dis_simple_stmt_str = """\
-   RESUME 0
+ 0 RESUME 0
 
  1 LOAD_NAME 0 (x)
  LOAD_CONST 0 (1)
@@ -297,7 +297,7 @@ def bug42562():
 # leading newline is for a reason (tests lineno)
 
 dis_annot_stmt_str = """\
-   RESUME 0
+ 0 RESUME 0
 
  2 SETUP_ANNOTATIONS
  LOAD_CONST 0 (1)
@@ -335,7 +335,7 @@ def bug42562():
 # Trailing newline has been deliberately omitted
 
 dis_compound_stmt_str = """\
-   RESUME 0
+ 0 RESUME 0
 
  1 LOAD_CONST 0 (0)
  STORE_NAME 0 (x)
@@ -1092,7 +1092,7 @@ def test_super_instructions(self):
  @cpython_only
  def test_binary_specialize(self):
  binary_op_quicken = """\
-   0 RESUME_QUICK 0
+ 0 0 RESUME_QUICK 0
 
  1 2 LOAD_NAME 0 (a)
  4 LOAD_NAME 1 (b)
@@ -1110,7 +1110,7 @@ def test_binary_specialize(self):
  self.do_disassembly_compare(got, binary_op_quicken % "BINARY_OP_ADD_UNICODE 0 (+)", True)
 
  binary_subscr_quicken = """\
-   0 RESUME_QUICK 0
+ 0 0 RESUME_QUICK 0
 
  1 2 LOAD_NAME 0 (a)
  4 LOAD_CONST 0 (0)
@@ -1130,7 +1130,7 @@ def test_binary_specialize(self):
  @cpython_only
  def test_load_attr_specialize(self):
  load_attr_quicken = """\
-   0 RESUME_QUICK 0
+ 0 0 RESUME_QUICK 0
 
  1 2 LOAD_CONST 0 ('a')
  4 LOAD_ATTR_SLOT 0 (__class__)
@@ -1144,7 +1144,7 @@ def test_load_attr_specialize(self):
  @cpython_only
  def test_call_specialize(self):
  call_quicken = """\
-   RESUME_QUICK 0
+ 0 RESUME_QUICK 0
 
  1 PUSH_NULL
  LOAD_NAME 0 (str)
@@ -1718,7 +1718,7 @@ def test_co_positions(self):
  for instr in dis.get_instructions(code)
  ]
  expected = [
- (None, None, None, None),
+ (0, 1, 0, 0),
  (1, 1, 0, 1),
  (1, 1, 0, 1),
  (2, 2, 2, 3),

Misc/NEWS.d/next/Core and Builtins/2022-07-01-20-00-19.gh-issue-94485.mo5st7.rst

@@ -0,0 +1,2 @@
+Line number of a module's ``RESUME`` instruction is set to 0 as specified in
+:pep:`626`.

Python/compile.c

@@ -1759,14 +1759,17 @@ compiler_enter_scope(struct compiler *c, identifier name,
  c->u->u_curblock = block;
 
  if (u->u_scope_type == COMPILER_SCOPE_MODULE) {
- c->u->u_loc.lineno = -1;
+ c->u->u_loc.lineno = 0;
  }
  else {
  if (!compiler_set_qualname(c))
  return 0;
  }
  ADDOP_I(c, RESUME, 0);
 
+ if (u->u_scope_type == COMPILER_SCOPE_MODULE) {
+ c->u->u_loc.lineno = -1;
+ }
  return 1;
 }