From: Dino Viehland <dinoviehland@meta.com>
Date: Mon, 8 Sep 2025 20:53:12 +0000 (-0700)
Subject: gh-138679: Opcodes which consume no inputs should indicate they produced the val... 
X-Git-Tag: v3.15.0a1~441
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=1561385863adb3dca0d554633090bc1d13aab415;p=thirdparty%2FPython%2Fcpython.git

gh-138679: Opcodes which consume no inputs should indicate they produced the val… (#138678)

Opcodes which consume no inputs should indicate they produced the value, not an arbitrary local
---

diff --git a/Lib/test/test_peepholer.py b/Lib/test/test_peepholer.py
index 98629df45746..1caf6de4a14e 100644
--- a/Lib/test/test_peepholer.py
+++ b/Lib/test/test_peepholer.py
@@ -1116,6 +1116,13 @@ class TestMarkingVariablesAsUnKnown(BytecodeTestCase):
         self.assertInBytecode(f, "LOAD_FAST_BORROW")
         self.assertNotInBytecode(f, "LOAD_FAST_CHECK")
 
+    def test_import_from_doesnt_clobber_load_fast_borrow(self):
+        def f(self):
+            if x: pass
+            self.x
+            from shutil import ExecError
+            print(ExecError)
+        self.assertInBytecode(f, "LOAD_FAST_BORROW", "self")
 
 class DirectCfgOptimizerTests(CfgOptimizationTestCase):
 
diff --git a/Python/flowgraph.c b/Python/flowgraph.c
index 3a29845db9f7..18594ca2f44c 100644
--- a/Python/flowgraph.c
+++ b/Python/flowgraph.c
@@ -2891,7 +2891,7 @@ optimize_load_fast(cfg_builder *g)
                     int num_pushed = _PyOpcode_num_pushed(opcode, oparg);
                     int net_pushed = num_pushed - num_popped;
                     assert(net_pushed >= 0);
-                    for (int i = 0; i < net_pushed; i++) {
+                    for (int j = 0; j < net_pushed; j++) {
                         PUSH_REF(i, NOT_LOCAL);
                     }
                     break;