- Improve $this assignment detection and generalize some code in zend_compile.c

diff --git a/Zend/zend_compile.c b/Zend/zend_compile.c
index 969c15998b284572c9a7fb44c9663e807a9af895..e979bb78835a9bf97d9fd5ccef32f951d68bdd51 100644 (file)
--- a/Zend/zend_compile.c
+++ b/Zend/zend_compile.c
@@ -464,6 +464,17 @@ void zend_do_abstract_method(znode *function_name, znode *modifiers, znode *body
        }
 }
 
+static zend_bool opline_is_fetch_this(zend_op *opline TSRMLS_DC)
+{
+       if (CG(active_class_entry) && (opline->opcode == ZEND_FETCH_W) && (opline->op1.op_type == IS_CONST)
+               && (opline->op1.u.constant.type == IS_STRING)
+               && (opline->op1.u.constant.value.str.len == (sizeof("this")-1))
+               && !memcmp(opline->op1.u.constant.value.str.val, "this", sizeof("this"))) {
+               return 1;
+       } else {
+               return 0;
+       }
+}
 
 void zend_do_assign(znode *result, znode *variable, znode *value TSRMLS_DC)
 {
@@ -487,10 +498,7 @@ void zend_do_assign(znode *result, znode *variable, znode *value TSRMLS_DC)
                SET_UNUSED(opline->result);
                *result = last_op->result;
        } else {
-               if (CG(active_class_entry) && (last_op->opcode == ZEND_FETCH_W) && (last_op->op1.op_type == IS_CONST)
-                       && (last_op->op1.u.constant.type == IS_STRING)
-                       && (last_op->op1.u.constant.value.str.len == (sizeof("this")-1))
-                       && !memcmp(last_op->op1.u.constant.value.str.val, "this", sizeof("this"))) {
+               if (opline_is_fetch_this(last_op TSRMLS_CC)) {
                        zend_error(E_COMPILE_ERROR, "Cannot re-assign $this");
                }
 
@@ -507,9 +515,14 @@ void zend_do_assign(znode *result, znode *variable, znode *value TSRMLS_DC)
 
 void zend_do_assign_ref(znode *result, znode *lvar, znode *rvar TSRMLS_DC)
 {
+       int last_op_number = get_next_op_number(CG(active_op_array))-1;
        zend_op *opline = get_next_op(CG(active_op_array) TSRMLS_CC);
+       zend_op *last_op = &CG(active_op_array)->opcodes[last_op_number];
 
        opline->opcode = ZEND_ASSIGN_REF;
+       if (opline_is_fetch_this(last_op TSRMLS_CC)) {
+               zend_error(E_COMPILE_ERROR, "Cannot re-assign $this");
+       }
        if (result) {
                opline->result.op_type = IS_VAR;
                opline->result.u.EA.type = 0;
@@ -804,12 +817,8 @@ void zend_do_end_variable_parse(int type, int arg_offset TSRMLS_DC)
                num_of_created_opcodes++;
        }
 
-       if (num_of_created_opcodes == 1) {
-               if ((opline_ptr->op1.op_type == IS_CONST) && (opline_ptr->op1.u.constant.type == IS_STRING) &&
-               (opline_ptr->op1.u.constant.value.str.len == (sizeof("this")-1)) &&
-               !memcmp(opline_ptr->op1.u.constant.value.str.val, "this", sizeof("this"))) {
-                       CG(active_op_array)->uses_this = 1;
-               }
+       if (num_of_created_opcodes == 1 && opline_is_fetch_this(opline_ptr TSRMLS_CC)) {
+               CG(active_op_array)->uses_this = 1;
        }
 
        zend_llist_destroy(fetch_list_ptr);
@@ -2582,9 +2591,7 @@ void zend_do_fetch_property(znode *result, znode *object, znode *property TSRMLS
                le = fetch_list_ptr->head;
                opline_ptr = (zend_op *) le->data;
 
-               if ((opline_ptr->op1.op_type == IS_CONST) && (opline_ptr->op1.u.constant.type == IS_STRING) &&
-                       (opline_ptr->op1.u.constant.value.str.len == (sizeof("this")-1)) &&
-                       !memcmp(opline_ptr->op1.u.constant.value.str.val, "this", sizeof("this"))) {
+               if (opline_is_fetch_this(opline_ptr TSRMLS_CC)) {
                        efree(opline_ptr->op1.u.constant.value.str.val);
                        SET_UNUSED(opline_ptr->op1); /* this means $this for objects */
                        opline_ptr->op2 = *property;