From: Zeev Suraski <zeev@php.net>
Date: Sun, 14 Dec 2003 16:09:07 +0000 (+0000)
Subject: Fix behavior of return-by-reference functions.  Remove erroneous warnings,
X-Git-Tag: php-5.0.0b3RC1~77
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=3a42babad6b6d8d39310df94f49b34f03e20e244;p=php

Fix behavior of return-by-reference functions.  Remove erroneous warnings,
add E_STRICT warnings in case you return something by reference that you're
not supposed to (anything that's not a variable, or a return-value of a
function that returned by reference).
---

diff --git a/Zend/zend_compile.c b/Zend/zend_compile.c
index d121d677d0..9b0cdb93a4 100644
--- a/Zend/zend_compile.c
+++ b/Zend/zend_compile.c
@@ -739,7 +739,7 @@ void zend_check_writable_variable(znode *variable)
 	}
 }
 
-zend_bool zend_is_function_or_method_call(znode *variable)
+static inline zend_bool zend_is_function_or_method_call(znode *variable)
 {
 	zend_uint type = variable->u.EA.type;
 
@@ -1475,10 +1475,6 @@ void zend_do_return(znode *expr, int do_end_vparse TSRMLS_DC)
 		} else {
 			zend_do_end_variable_parse(BP_VAR_R, 0 TSRMLS_CC);
 		}
-#if 0
-	} else if (expr && CG(active_op_array)->return_reference) {
-		zend_error(E_COMPILE_ERROR, "Only variables may be returned by reference");
-#endif
 	}
 
 #ifdef ZTS
@@ -1499,6 +1495,15 @@ void zend_do_return(znode *expr, int do_end_vparse TSRMLS_DC)
 		opline->op1.op_type = IS_CONST;
 		INIT_ZVAL(opline->op1.u.constant);
 	}
+
+	if (do_end_vparse) {
+		if (zend_is_function_or_method_call(expr)) {
+			opline->extended_value = ZEND_RETURNS_FUNCTION;	
+		} else {
+			opline->extended_value = 0;
+		}
+	}
+
 	SET_UNUSED(opline->op2);
 }
 
diff --git a/Zend/zend_compile.h b/Zend/zend_compile.h
index 381b82190e..67fe568c1b 100644
--- a/Zend/zend_compile.h
+++ b/Zend/zend_compile.h
@@ -790,6 +790,9 @@ int zendlex(znode *zendlval TSRMLS_DC);
 #define ZEND_RETURN_VAL 0
 #define ZEND_RETURN_REF 1
 
+
+#define ZEND_RETURNS_FUNCTION 1<<0
+
 END_EXTERN_C()
 
 #define ZEND_CLONE_FUNC_NAME		"__clone"
diff --git a/Zend/zend_execute.c b/Zend/zend_execute.c
index 3491e76cc0..4c42e48344 100644
--- a/Zend/zend_execute.c
+++ b/Zend/zend_execute.c
@@ -2512,6 +2512,8 @@ int zend_do_fcall_common_helper(ZEND_OPCODE_HANDLER_ARGS)
 		should_change_scope = 0;
 	}
 
+	EX_T(EX(opline)->result.u.var).var.fcall_returned_reference = 0;
+
 	if (EX(function_state).function->type == ZEND_INTERNAL_FUNCTION) {	
 		ALLOC_ZVAL(EX_T(EX(opline)->result.u.var).var.ptr);
 		INIT_ZVAL(*(EX_T(EX(opline)->result.u.var).var.ptr));
@@ -2561,6 +2563,7 @@ int zend_do_fcall_common_helper(ZEND_OPCODE_HANDLER_ARGS)
 		EG(active_op_array) = (zend_op_array *) EX(function_state).function;
 
 		zend_execute(EG(active_op_array) TSRMLS_CC);
+		EX_T(EX(opline)->result.u.var).var.fcall_returned_reference = EG(active_op_array)->return_reference;
 
 		if (return_value_used && !EX_T(EX(opline)->result.u.var).var.ptr) {
 			if (!EG(exception)) {
@@ -2685,20 +2688,28 @@ int zend_return_handler(ZEND_OPCODE_HANDLER_ARGS)
 {
 	zval *retval_ptr;
 	zval **retval_ptr_ptr;
-	
-	if ((EG(active_op_array)->return_reference == ZEND_RETURN_REF) &&
-		(EX(opline)->op1.op_type != IS_CONST) && 
-		(EX(opline)->op1.op_type != IS_TMP_VAR)) {
-		
+			
+	if (EG(active_op_array)->return_reference == ZEND_RETURN_REF) {
+		if (EX(opline)->op1.op_type == IS_CONST || EX(opline)->op1.op_type == IS_TMP_VAR) {
+			/* Not supposed to happen, but we'll allow it */
+			zend_error(E_STRICT, "Only variable references should be returned by reference");
+			goto return_by_value;
+		}
+
 		retval_ptr_ptr = get_zval_ptr_ptr(&EX(opline)->op1, EX(Ts), BP_VAR_W);
 
 		if (!retval_ptr_ptr) {
-			zend_error(E_ERROR, "Cannot return overloaded elements or string offsets by reference");
+			zend_error(E_ERROR, "Cannot return string offsets by reference");
 		}
 
 		if (!(*retval_ptr_ptr)->is_ref
-			&& EX_T(EX(opline)->op1.u.var).var.ptr_ptr == &EX_T(EX(opline)->op1.u.var).var.ptr) {
-			zend_error(E_ERROR, "Only variables or references can be returned by reference");
+			/*&& EX_T(EX(opline)->op1.u.var).var.ptr_ptr == &EX_T(EX(opline)->op1.u.var).var.ptr*/) {
+			if (EX(opline)->extended_value == ZEND_RETURNS_FUNCTION
+				&& !EX_T(EX(opline)->op1.u.var).var.fcall_returned_reference) {
+				zend_error(E_STRICT, "Only variable references should be returned by reference");
+				PZVAL_LOCK(*retval_ptr_ptr); /* undo the effect of get_zval_ptr_ptr() */
+				goto return_by_value;
+			}
 		}
 		
 		SEPARATE_ZVAL_TO_MAKE_IS_REF(retval_ptr_ptr);
@@ -2706,6 +2717,7 @@ int zend_return_handler(ZEND_OPCODE_HANDLER_ARGS)
 		
 		(*EG(return_value_ptr_ptr)) = (*retval_ptr_ptr);
 	} else {
+return_by_value:
 		retval_ptr = get_zval_ptr(&EX(opline)->op1, EX(Ts), &EG(free_op1), BP_VAR_R);
 	
 		if (!EG(free_op1)) { /* Not a temp var */
diff --git a/Zend/zend_execute.h b/Zend/zend_execute.h
index ce7541f546..087fcf1911 100644
--- a/Zend/zend_execute.h
+++ b/Zend/zend_execute.h
@@ -36,6 +36,7 @@ typedef union _temp_variable {
 			zval *str;
 			zend_uint offset;
 		} str_offset;
+		zend_bool fcall_returned_reference;
 	} var;
 	zend_class_entry *class_entry;
 } temp_variable;