From: Irit Katriel <1055913+iritkatriel@users.noreply.github.com>
Date: Tue, 20 Aug 2024 10:39:41 +0000 (+0100)
Subject: gh-123048: Fix missing source location in pattern matching code (#123167)
X-Git-Tag: v3.14.0a1~737
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bffed80230f2617de2ee02bd4bdded1024234dab;p=thirdparty%2FPython%2Fcpython.git

gh-123048: Fix missing source location in pattern matching code (#123167)
---

diff --git a/Lib/test/test_patma.py b/Lib/test/test_patma.py
index 1bdab125dc6e..8325b83a5932 100644
--- a/Lib/test/test_patma.py
+++ b/Lib/test/test_patma.py
@@ -1,6 +1,7 @@
 import array
 import collections
 import dataclasses
+import dis
 import enum
 import inspect
 import sys
@@ -3377,6 +3378,24 @@ class TestValueErrors(unittest.TestCase):
         self.assertIs(y, None)
         self.assertIs(z, None)
 
+class TestSourceLocations(unittest.TestCase):
+    def test_jump_threading(self):
+        # See gh-123048
+        def f():
+            x = 0
+            v = 1
+            match v:
+                case 1:
+                    if x < 0:
+                        x = 1
+                case 2:
+                    if x < 0:
+                        x = 1
+            x += 1
+
+        for inst in dis.get_instructions(f):
+            if inst.opcode in dis.hasjump:
+                self.assertIsNotNone(inst.positions.lineno, "jump without location")
 
 class TestTracing(unittest.TestCase):
 
diff --git a/Misc/NEWS.d/next/Core and Builtins/2024-08-20-11-09-16.gh-issue-123048.2TISpv.rst b/Misc/NEWS.d/next/Core and Builtins/2024-08-20-11-09-16.gh-issue-123048.2TISpv.rst
new file mode 100644
index 000000000000..f0b756febbc1
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2024-08-20-11-09-16.gh-issue-123048.2TISpv.rst	
@@ -0,0 +1,2 @@
+Fix a bug where pattern matching code could emit a :opcode:`JUMP_FORWARD`
+with no source location.
diff --git a/Python/compile.c b/Python/compile.c
index 0a338b169872..c369202d53b3 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -7301,7 +7301,7 @@ codegen_match_inner(struct compiler *c, stmt_ty s, pattern_context *pc)
             ADDOP(c, LOC(m->pattern), POP_TOP);
         }
         VISIT_SEQ(c, stmt, m->body);
-        ADDOP_JUMP(c, NO_LOCATION, JUMP_NO_INTERRUPT, end);
+        ADDOP_JUMP(c, NO_LOCATION, JUMP, end);
         // If the pattern fails to match, we want the line number of the
         // cleanup to be associated with the failed pattern, not the last line
         // of the body