bpo-44297: Fix missing line number in generator expressions (GH-26801)

markshannon · web-flow · commit 82e5c28af704 · 2021-06-21T10:55:15.000+01:00
* Make sure that line number is set when entering comprehension scope in compiler.
diff --git a/Lib/test/test_compile.py b/Lib/test/test_compile.py
@@ -895,6 +895,21 @@ def aug_store_attr():
                               for (_, _, line) in func.__code__.co_lines() ]
                 self.assertEqual(lines, code_lines)
 
+    def test_line_number_genexp(self):
+
+        def return_genexp():
+            return (1
+                    for
+                    x
+                    in
+                    y)
+        genexp_lines = [None, 1, 3, 1]
+
+        genexp_code = return_genexp.__code__.co_consts[1]
+        code_lines = [None if line is None else line-return_genexp.__code__.co_firstlineno
+                      for (_, _, line) in genexp_code.co_lines() ]
+        self.assertEqual(genexp_lines, code_lines)
+
 
     def test_big_dict_literal(self):
         # The compiler has a flushing point in "compiler_dict" that calls compiles
diff --git a/Misc/NEWS.d/next/Core and Builtins/2021-06-19-12-41-13.bpo-44297.F53vHj.rst b/Misc/NEWS.d/next/Core and Builtins/2021-06-19-12-41-13.bpo-44297.F53vHj.rst
@@ -0,0 +1,3 @@
+Make sure that the line number is set when entering a comprehension scope.
+Ensures that backtraces inclusing generator expressions show the correct
+line number.
diff --git a/Python/compile.c b/Python/compile.c
@@ -4900,6 +4900,7 @@ compiler_comprehension(struct compiler *c, expr_ty e, int type,
     {
         goto error;
     }
+    SET_LOC(c, e);
 
     is_async_generator = c->u->u_ste->ste_coroutine;
 
diff --git a/Python/importlib_external.h b/Python/importlib_external.h

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	`+Make sure that the line number is set when entering a comprehension scope.`
	`2`	`+Ensures that backtraces inclusing generator expressions show the correct`
	`3`	`+line number.`
Original file line number	Diff line number	Diff line change
`@@ -4900,6 +4900,7 @@ compiler_comprehension(struct compiler *c, expr_ty e, int type,`
`4900`	`4900`	`{`
`4901`	`4901`	`goto error;`
`4902`	`4902`	`}`
	`4903`	`+ SET_LOC(c, e);`
`4903`	`4904`
`4904`	`4905`	`is_async_generator = c->u->u_ste->ste_coroutine;`
`4905`	`4906`