From: Nikita Popov <nikita.ppv@gmail.com>
Date: Mon, 27 May 2019 15:11:44 +0000 (+0200)
Subject: BIND_STATIC of implicit binding may be undef
X-Git-Tag: php-7.4.0alpha1~185
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=fd23f9104a9772234a3469e341500cf1b9503f63;p=php

BIND_STATIC of implicit binding may be undef

Even though we don't need it at runtime, add the BIND_IMPLICIT
flag to BIND_STATIC as well, so we can distinguish this case in
type inference.

This fixes a JIT miscompile in arrow_functions/002.phpt.
---

diff --git a/Zend/zend_compile.c b/Zend/zend_compile.c
index d0d5c7af19..b4d4012d7f 100644
--- a/Zend/zend_compile.c
+++ b/Zend/zend_compile.c
@@ -4012,7 +4012,7 @@ void zend_compile_global_var(zend_ast *ast) /* {{{ */
 }
 /* }}} */
 
-static void zend_compile_static_var_common(zend_string *var_name, zval *value, uint32_t by_ref) /* {{{ */
+static void zend_compile_static_var_common(zend_string *var_name, zval *value, uint32_t mode) /* {{{ */
 {
 	zend_op *opline;
 	if (!CG(active_op_array)->static_variables) {
@@ -4031,7 +4031,7 @@ static void zend_compile_static_var_common(zend_string *var_name, zval *value, u
 	opline = zend_emit_op(NULL, ZEND_BIND_STATIC, NULL, NULL);
 	opline->op1_type = IS_CV;
 	opline->op1.var = lookup_cv(var_name);
-	opline->extended_value = (uint32_t)((char*)value - (char*)CG(active_op_array)->static_variables->arData) | by_ref;
+	opline->extended_value = (uint32_t)((char*)value - (char*)CG(active_op_array)->static_variables->arData) | mode;
 }
 /* }}} */
 
@@ -5584,7 +5584,7 @@ static void zend_compile_closure_uses(zend_ast *ast) /* {{{ */
 			}
 		}
 
-		zend_compile_static_var_common(var_name, &zv, var_ast->attr);
+		zend_compile_static_var_common(var_name, &zv, var_ast->attr ? ZEND_BIND_REF : 0);
 	}
 }
 /* }}} */
@@ -5595,7 +5595,7 @@ static void zend_compile_implicit_closure_uses(closure_info *info)
 	ZEND_HASH_FOREACH_STR_KEY(&info->uses, var_name)
 		zval zv;
 		ZVAL_NULL(&zv);
-		zend_compile_static_var_common(var_name, &zv, 0);
+		zend_compile_static_var_common(var_name, &zv, ZEND_BIND_IMPLICIT);
 	ZEND_HASH_FOREACH_END();
 }
 
diff --git a/Zend/zend_vm_def.h b/Zend/zend_vm_def.h
index 8fae94fc49..50ce8c1e92 100644
--- a/Zend/zend_vm_def.h
+++ b/Zend/zend_vm_def.h
@@ -8220,7 +8220,7 @@ ZEND_VM_HANDLER(183, ZEND_BIND_STATIC, CV, UNUSED, REF)
 		ZEND_MAP_PTR_SET(EX(func)->op_array.static_variables_ptr, ht);
 	}
 
-	value = (zval*)((char*)ht->arData + (opline->extended_value & ~ZEND_BIND_REF));
+	value = (zval*)((char*)ht->arData + (opline->extended_value & ~(ZEND_BIND_REF|ZEND_BIND_IMPLICIT)));
 
 	if (opline->extended_value & ZEND_BIND_REF) {
 		if (Z_TYPE_P(value) == IS_CONSTANT_AST) {
diff --git a/Zend/zend_vm_execute.h b/Zend/zend_vm_execute.h
index fbcd28de38..26bd027f3f 100644
--- a/Zend/zend_vm_execute.h
+++ b/Zend/zend_vm_execute.h
@@ -50848,7 +50848,7 @@ static ZEND_OPCODE_HANDLER_RET ZEND_FASTCALL ZEND_BIND_STATIC_SPEC_CV_UNUSED_HAN
 		ZEND_MAP_PTR_SET(EX(func)->op_array.static_variables_ptr, ht);
 	}
 
-	value = (zval*)((char*)ht->arData + (opline->extended_value & ~ZEND_BIND_REF));
+	value = (zval*)((char*)ht->arData + (opline->extended_value & ~(ZEND_BIND_REF|ZEND_BIND_IMPLICIT)));
 
 	if (opline->extended_value & ZEND_BIND_REF) {
 		if (Z_TYPE_P(value) == IS_CONSTANT_AST) {
diff --git a/ext/opcache/Optimizer/zend_inference.c b/ext/opcache/Optimizer/zend_inference.c
index d6e3b4fa0d..866cfd06bb 100644
--- a/ext/opcache/Optimizer/zend_inference.c
+++ b/ext/opcache/Optimizer/zend_inference.c
@@ -3025,6 +3025,9 @@ static int zend_update_type_info(const zend_op_array *op_array,
 		case ZEND_BIND_STATIC:
 			tmp = MAY_BE_ANY | MAY_BE_ARRAY_KEY_ANY | MAY_BE_ARRAY_OF_ANY | MAY_BE_ARRAY_OF_REF
 				| ((opline->extended_value & ZEND_BIND_REF) ? MAY_BE_REF : (MAY_BE_RC1 | MAY_BE_RCN));
+			if (opline->extended_value & ZEND_BIND_IMPLICIT) {
+				tmp |= MAY_BE_UNDEF;
+			}
 			UPDATE_SSA_TYPE(tmp, ssa_ops[i].op1_def);
 			break;
 		case ZEND_SEND_VAR: