From fc35a6b93cfbd5be83d61b226e1286254e4cbf73 Mon Sep 17 00:00:00 2001
From: Dmitry Stogov <dmitry@zend.com>
Date: Mon, 15 Nov 2021 23:25:16 +0300
Subject: [PATCH] Tracing JIT: Fixed abstract stack consistency for [QM_]ASSIGN
 of CV to itself

---
 ext/opcache/jit/zend_jit_trace.c         | 10 ++++++--
 ext/opcache/tests/jit/qm_assign_002.phpt | 29 ++++++++++++++++++++++++
 2 files changed, 37 insertions(+), 2 deletions(-)
 create mode 100644 ext/opcache/tests/jit/qm_assign_002.phpt

diff --git a/ext/opcache/jit/zend_jit_trace.c b/ext/opcache/jit/zend_jit_trace.c
index d20e7060290..fa29a039977 100644
--- a/ext/opcache/jit/zend_jit_trace.c
+++ b/ext/opcache/jit/zend_jit_trace.c
@@ -5904,7 +5904,10 @@ done:
 						ssa->var_info[ssa_op->result_def].has_range = 1;
 					}
 				}
-				if (ssa_op->op1_def >= 0) {
+				if (ssa_op->op1_def >= 0
+				 && (opline->opcode != ZEND_QM_ASSIGN
+				  || opline->result_type != IS_CV
+				  || opline->result.var != opline->op1.var)) {
 					zend_uchar type = IS_UNKNOWN;
 
 					if (!(ssa->var_info[ssa_op->op1_def].type & MAY_BE_GUARD)
@@ -5963,7 +5966,10 @@ done:
 						ssa->var_info[ssa_op->op1_def].has_range = 1;
 					}
 				}
-				if (ssa_op->op2_def >= 0) {
+				if (ssa_op->op2_def >= 0
+				 && (opline->opcode != ZEND_ASSIGN
+				  || opline->op1_type != IS_CV
+				  || opline->op1.var != opline->op2.var)) {
 					zend_uchar type = IS_UNKNOWN;
 
 					if (!(ssa->var_info[ssa_op->op2_def].type & MAY_BE_GUARD)
diff --git a/ext/opcache/tests/jit/qm_assign_002.phpt b/ext/opcache/tests/jit/qm_assign_002.phpt
new file mode 100644
index 00000000000..ebfb46e227e
--- /dev/null
+++ b/ext/opcache/tests/jit/qm_assign_002.phpt
@@ -0,0 +1,29 @@
+--TEST--
+JIT QM_ASSIGN: 002 assign to it self
+--INI--
+opcache.enable=1
+opcache.enable_cli=1
+opcache.file_update_protection=0
+opcache.jit_buffer_size=1M
+--FILE--
+<?php
+function test() {
+    for ($i = 0; $i < 2; $i++) {
+        $a = $a;
+        "-" . $b;
+        $b = [];
+        unset($a);
+    }
+}
+test();
+?>
+DONE
+--EXPECTF--
+Warning: Undefined variable $a in %sqm_assign_002.php on line 4
+
+Warning: Undefined variable $b in %sqm_assign_002.php on line 5
+
+Warning: Undefined variable $a in %sqm_assign_002.php on line 4
+
+Warning: Array to string conversion in %sqm_assign_002.php on line 5
+DONE
\ No newline at end of file