From: Andi Gutmans <andi@php.net>
Date: Fri, 15 Mar 2002 15:09:46 +0000 (+0000)
Subject: - Fix issues with $this when using it by itself without indirection such as
X-Git-Tag: php-4.3.0dev-ZendEngine2-Preview1~1391
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=0ce019f715c26ef20aa768c08540f6c7d53753ff;p=php

- Fix issues with $this when using it by itself without indirection such as
- $this->foo.
---

diff --git a/Zend/zend_compile.c b/Zend/zend_compile.c
index 235fc5cd0d..674aa0c429 100644
--- a/Zend/zend_compile.c
+++ b/Zend/zend_compile.c
@@ -285,14 +285,7 @@ void fetch_simple_variable_ex(znode *result, znode *varname, int bp, int op TSRM
 	*result = opline_ptr->result;
 	SET_UNUSED(opline_ptr->op2);
 
-	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"))) {
-		opline_ptr->op2.u.EA.type = ZEND_FETCH_THIS;
-		efree(varname->u.constant.value.str.val);
-		memset(&opline_ptr->op1, 0, sizeof(znode));
-		SET_UNUSED(opline_ptr->op1);
-	} else if (varname->op_type == IS_CONST && varname->u.constant.type == IS_STRING
+	if (varname->op_type == IS_CONST && varname->u.constant.type == IS_STRING
 		&& zend_hash_exists(CG(auto_globals), varname->u.constant.value.str.val, varname->u.constant.value.str.len+1)) {
 		opline_ptr->op2.u.EA.type = ZEND_FETCH_GLOBAL;
 	} else {
@@ -722,6 +715,7 @@ void zend_do_end_variable_parse(int type, int arg_offset TSRMLS_DC)
 	zend_llist *fetch_list_ptr;
 	zend_llist_element *le;
 	zend_op *opline, *opline_ptr;
+	int num_of_created_opcodes = 0;
 
 	/*
 	if (zend_variable_buffer_empty(TSRMLS_C) && (type == BP_VAR_W || type == BP_VAR_RW)) {
@@ -763,7 +757,17 @@ void zend_do_end_variable_parse(int type, int arg_offset TSRMLS_DC)
 				break;
 		}
 		le = le->next;
+		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;
+		}
 	}
+
 	zend_llist_destroy(fetch_list_ptr);
 	zend_stack_del_top(&CG(bp_stack));
 }
@@ -2202,7 +2206,10 @@ 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_UNUSED && opline_ptr->op2.u.EA.type == ZEND_FETCH_THIS) {
+		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"))) {
+			efree(opline_ptr->op1.u.constant.value.str.val);
 			opline_ptr->op1 = *property;
 			SET_UNUSED(opline_ptr->op2);
 			opline_ptr->op2.u.EA.type = ZEND_FETCH_FROM_THIS;
diff --git a/Zend/zend_compile.h b/Zend/zend_compile.h
index 330bad464c..4dc3a17261 100644
--- a/Zend/zend_compile.h
+++ b/Zend/zend_compile.h
@@ -103,6 +103,7 @@ struct _zend_op_array {
 
 	zend_bool return_reference;
 	zend_bool done_pass_two;
+	zend_bool uses_this;
 
 	char *filename;
 
@@ -589,7 +590,6 @@ int zendlex(znode *zendlval TSRMLS_DC);
 #define ZEND_FETCH_STATIC			2
 #define ZEND_FETCH_STATIC_MEMBER	3
 #define ZEND_FETCH_FROM_THIS		4
-#define ZEND_FETCH_THIS				5
 
 /* class fetches */
 #define ZEND_FETCH_CLASS_DEFAULT	0
diff --git a/Zend/zend_execute.c b/Zend/zend_execute.c
index 3eba1da4f8..ed3a25bc40 100644
--- a/Zend/zend_execute.c
+++ b/Zend/zend_execute.c
@@ -635,22 +635,6 @@ static inline HashTable *zend_get_target_symbol_table(zend_op *opline, temp_vari
 			/* HACK!! 'this' should be always zend_object */
 			return Z_OBJPROP_P(EG(This));
 			break;
-		case ZEND_FETCH_THIS:
-			{
-				if (!EG(This)) {
-					zend_error(E_ERROR, "Using $this when not in object context");
-				}
-				/* FIXME: Put this error back.
-				//if (type == BP_VAR_RW || type == BP_VAR_W) {
-				//	zend_error(E_ERROR, "Can't overwrite $this");
-				//}
-				*/
-				Ts[opline->result.u.var].var.ptr_ptr = &EG(This);
-				SELECTIVE_PZVAL_LOCK(EG(This), &opline->result);
-				AI_USE_PTR(Ts[opline->result.u.var].var);
-				return NULL;
-				break;
-			}
 		EMPTY_SWITCH_DEFAULT_CASE()
 	}
 	return NULL;
@@ -1179,6 +1163,13 @@ ZEND_API void execute(zend_op_array *op_array TSRMLS_DC)
 		EX(opline) = op_array->opcodes;
 	}
 
+	if (op_array->uses_this && EG(This)) {
+		EG(This)->refcount++; /* For $this pointer */
+		if (zend_hash_add(EG(active_symbol_table), "this", sizeof("this"), &EG(This), sizeof(zval *), NULL)==FAILURE) {
+			EG(This)->refcount--;
+		}
+	}
+
 	EG(opline_ptr) = &EX(opline);
 
 	EX(function_state).function = (zend_function *) op_array;
@@ -2815,42 +2806,27 @@ send_by_ref:
 
 			
 					unset_object = (EX(opline)->extended_value == ZEND_UNSET_OBJ);
-					if (EX(opline)->op2.u.EA.type == ZEND_FETCH_THIS) {
-						if (!EG(This)) {
-							zend_error(E_WARNING, "Using $this in non-object context");
-						} else {
-							object = &EG(This);
-							if(unset_object) {
-								Z_OBJ_HT_PP(object)->delete_obj((*object));
-								zval_ptr_dtor(&EG(This));
-								EG(This) = NULL;
-							} else {
-								zend_error(E_WARNING, "$this cannot be unset");
-							}
-						}
-					} else {
-						if (variable->type != IS_STRING) {
-							tmp = *variable;
-							zval_copy_ctor(&tmp);
-							convert_to_string(&tmp);
-							variable = &tmp;
-						}
+					if (variable->type != IS_STRING) {
+						tmp = *variable;
+						zval_copy_ctor(&tmp);
+						convert_to_string(&tmp);
+						variable = &tmp;
+					}
 
-						if (unset_object) {
-							if (zend_hash_find(EG(active_symbol_table), variable->value.str.val, variable->value.str.len+1, (void **)&object) == FAILURE) {
-								zend_error(E_ERROR, "Cannot delete non-existing object");
-							}
-							if (Z_TYPE_PP(object) != IS_OBJECT) {
-							zend_error(E_ERROR, "Cannot call delete on non-object type");
-							}
-							Z_OBJ_HT_PP(object)->delete_obj((*object));
+					if (unset_object) {
+						if (zend_hash_find(EG(active_symbol_table), variable->value.str.val, variable->value.str.len+1, (void **)&object) == FAILURE) {
+							zend_error(E_ERROR, "Cannot delete non-existing object");
 						}
+						if (Z_TYPE_PP(object) != IS_OBJECT) {
+						zend_error(E_ERROR, "Cannot call delete on non-object type");
+						}
+						Z_OBJ_HT_PP(object)->delete_obj((*object));
+					}
 
-						zend_hash_del(EG(active_symbol_table), variable->value.str.val, variable->value.str.len+1);
+					zend_hash_del(EG(active_symbol_table), variable->value.str.val, variable->value.str.len+1);
 
-						if (variable == &tmp) {
-							zval_dtor(&tmp);
-						}
+					if (variable == &tmp) {
+						zval_dtor(&tmp);
 					}
 					FREE_OP(EX(Ts), &EX(opline)->op1, EG(free_op1));
 				}
@@ -3048,28 +3024,19 @@ send_by_ref:
 					zend_bool isset = 1;
 					HashTable *target_symbol_table;
 		
-					if (EX(opline)->op2.u.EA.type == ZEND_FETCH_THIS) {
-						if (!EG(This)) {
-							isset = 0;
-						} else {
-							isset = 1;
-							value = &EG(This);
-						}
-					} else {
-						target_symbol_table = zend_get_target_symbol_table(EX(opline), EX(Ts), BP_VAR_IS TSRMLS_CC);
+					target_symbol_table = zend_get_target_symbol_table(EX(opline), EX(Ts), BP_VAR_IS TSRMLS_CC);
 
-						if (variable->type != IS_STRING) {
-							tmp = *variable;
-							zval_copy_ctor(&tmp);
-							convert_to_string(&tmp);
-							variable = &tmp;
-						}
-						
-						if (zend_hash_find(target_symbol_table, variable->value.str.val, variable->value.str.len+1, (void **) &value) == FAILURE) {
-							isset = 0;
-						}
+					if (variable->type != IS_STRING) {
+						tmp = *variable;
+						zval_copy_ctor(&tmp);
+						convert_to_string(&tmp);
+						variable = &tmp;
 					}
-						
+					
+					if (zend_hash_find(target_symbol_table, variable->value.str.val, variable->value.str.len+1, (void **) &value) == FAILURE) {
+						isset = 0;
+					}
+					
 					EX(Ts)[EX(opline)->result.u.var].tmp_var.type = IS_BOOL;
 
 					switch (EX(opline)->extended_value) {
diff --git a/Zend/zend_opcode.c b/Zend/zend_opcode.c
index ed10615c83..221dee43ae 100644
--- a/Zend/zend_opcode.c
+++ b/Zend/zend_opcode.c
@@ -87,6 +87,8 @@ void init_op_array(zend_op_array *op_array, int type, int initial_ops_size TSRML
 	op_array->return_reference = 0;
 	op_array->done_pass_two = 0;
 
+	op_array->uses_this = 0;
+
 	op_array->start_op = NULL;
 
 	zend_llist_apply_with_argument(&zend_extensions, (llist_apply_with_arg_func_t) zend_extension_op_array_ctor_handler, op_array TSRMLS_CC);