Fixed bug #75893

It is not sufficient to just add the additional types for aliased
variables at the end of type inference, because types of derived
variables may depend on them. Make sure the additional types are
always added whenever the type of an aliased variable is updated.

Author: nikic

NEWS

@@ -21,6 +21,8 @@ PHP                                                                        NEWS
 
 - Opcache:
   . Fixed bug #75729 (opcache segfault when installing Bitrix). (Nikita)
+  . Fixed bug #75893 (file_get_contents $http_response_header variable bugged
+    with opcache). (Nikita)
 
 - Standard:
   . Fixed bug #75916 (DNS_CAA record results contain garbage). (Mike,

ext/opcache/Optimizer/zend_inference.c

@@ -1734,6 +1734,16 @@ static int zend_infer_ranges(const zend_op_array *op_array, zend_ssa *ssa) /* {{
 }
 /* }}} */
 
+static uint32_t get_ssa_alias_types(zend_ssa_alias_kind alias) {
+	if (alias == PHP_ERRORMSG_ALIAS) {
+		return MAY_BE_STRING | MAY_BE_RC1 | MAY_BE_RCN;
+	} else if (alias == HTTP_RESPONSE_HEADER_ALIAS) {
+		return MAY_BE_ARRAY | MAY_BE_ARRAY_KEY_LONG | MAY_BE_ARRAY_OF_STRING | MAY_BE_RC1 | MAY_BE_RCN;
+	} else {
+		return MAY_BE_UNDEF | MAY_BE_RC1 | MAY_BE_RCN | MAY_BE_REF | MAY_BE_ANY | MAY_BE_ARRAY_KEY_ANY | MAY_BE_ARRAY_OF_ANY | MAY_BE_ARRAY_OF_REF;
+	}
+}
+
 #define UPDATE_SSA_TYPE(_type, _var)									\
 	do {																\
 		uint32_t __type = (_type);										\
@@ -1742,14 +1752,18 @@ static int zend_infer_ranges(const zend_op_array *op_array, zend_ssa *ssa) /* {{
 			__type |= MAY_BE_RC1 | MAY_BE_RCN | MAY_BE_ANY | MAY_BE_ARRAY_KEY_ANY | MAY_BE_ARRAY_OF_ANY | MAY_BE_ARRAY_OF_REF; \
 		}																\
 		if (__var >= 0) {												\
-			if (ssa_vars[__var].var < op_array->last_var) {				\
+			zend_ssa_var *__ssa_var = &ssa_vars[__var];					\
+			if (__ssa_var->var < op_array->last_var) {					\
 				if (__type & (MAY_BE_REF|MAY_BE_RCN)) {					\
 					__type |= MAY_BE_RC1 | MAY_BE_RCN;					\
 				}														\
 				if ((__type & MAY_BE_RC1) && (__type & MAY_BE_STRING)) {\
 					/* TODO: support for array keys and ($str . "")*/   \
 					__type |= MAY_BE_RCN;                               \
 				}                                                       \
+				if (__ssa_var->alias) {									\
+					__type |= get_ssa_alias_types(__ssa_var->alias);	\
+				}														\
 			}															\
 			if (ssa_var_info[__var].type != __type) { 					\
 				if (ssa_var_info[__var].type & ~__type) {				\
@@ -3880,18 +3894,6 @@ static int zend_infer_types(const zend_op_array *op_array, const zend_script *sc
 	/* Narrowing integer initialization to doubles */
 	zend_type_narrowing(op_array, script, ssa);
 
-	for (j = 0; j < ssa_vars_count; j++) {
-		if (ssa->vars[j].alias) {
-			if (ssa->vars[j].alias == PHP_ERRORMSG_ALIAS) {
-				ssa_var_info[j].type |= MAY_BE_STRING | MAY_BE_RC1 | MAY_BE_RCN;
-			} else if (ssa->vars[j].alias == HTTP_RESPONSE_HEADER_ALIAS) {
-				ssa_var_info[j].type |= MAY_BE_ARRAY | MAY_BE_ARRAY_KEY_LONG | MAY_BE_ARRAY_OF_STRING | MAY_BE_RC1 | MAY_BE_RCN;
-			} else {
-				ssa_var_info[j].type = MAY_BE_UNDEF | MAY_BE_RC1 | MAY_BE_RCN | MAY_BE_REF | MAY_BE_ANY | MAY_BE_ARRAY_KEY_ANY | MAY_BE_ARRAY_OF_ANY | MAY_BE_ARRAY_OF_REF;
-			}
-		}
-	}
-
 	if (ZEND_FUNC_INFO(op_array)) {
 		zend_func_return_info(op_array, script, 1, 0, &ZEND_FUNC_INFO(op_array)->return_info);
 	}
@@ -3919,6 +3921,9 @@ int zend_ssa_inference(zend_arena **arena, const zend_op_array *op_array, const
 		for (i = 0; i < op_array->last_var; i++) {
 			ssa_var_info[i].type = MAY_BE_UNDEF;
 			ssa_var_info[i].has_range = 0;
+			if (ssa->vars[i].alias) {
+				ssa_var_info[i].type |= get_ssa_alias_types(ssa->vars[i].alias);
+			}
 		}
 	}
 	for (i = op_array->last_var; i < ssa->vars_count; i++) {

ext/opcache/tests/bug75893.phpt

@@ -0,0 +1,22 @@
+--TEST--
+Bug #75893: file_get_contents $http_response_header variable bugged with opcache
+--INI--
+opcache.enable_cli=1
+track_errors=1
+--FILE--
+<?php
+
+function test() {
+    echo $undef;
+    $foo = $php_errormsg;
+    var_dump($foo[0]);
+}
+
+test();
+
+?>
+--EXPECTF--
+Deprecated: Directive 'track_errors' is deprecated in Unknown on line 0
+
+Notice: Undefined variable: undef in %s on line %d
+string(1) "U"