gh-94485: Set line number of module's RESUME instruction to 0, as specified by PEP 626 (GH-94552)

Co-authored-by: Mark Shannon <mark@hotpy.org>

Author: iritkatriel

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`.

Programs/test_frozenmain.h

@@ -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;
 }