I have finished a patch that implements a working version of late static
binding.
I used the notes from the Paris PDM as my guidelines for implementation.
(http://www.php.net/~derick/meeting-notes.html#late-static-binding-using-this-without-or-perhaps-with-a-different-name)
As requested in the notes I reused 'static::'. I also wrote a few tests not
only to test the new functionality but also to make sure 'static' can't be
inherited or extended.
I also added a new function get_caller_class() which returns the name of
the class that static:: would represent.
(borrowing from PDM notes)
In php5.* the following script outputs "A::static2":
<?php
class A {
static function staticA() {
self::static2();
}
static function static2() {
echo "A::static2\n";
}
}
class B extends A {
static function static2() {
echo "B::static2\n";
}
}
B::staticA();
?>
This has somewhat recently been highlighted by different developers to
be somewhat problematic behavior in creating user friendly APIs. If you
want to see a possible use for it you need look no further than the
example ZActiveRecord API that was used in their webcast with php|arch.
(http://blog.joshuaeichorn.com/archives/2006/01/09/zactiverecord-cant-work/)
Currently the code laid out there is impossible short of some ugly use of
debug_backtrace() and file parsing :/. This patch of course would allow that
kind of code too exist.
In a small example based on the one I gave earlier you could change the
code too the following and have it print "B::static2":
<?php
class A {
static function staticA() {
static::static2();
}
static function static2() {
echo "A::static2\n";
}
}
class B extends A {
static function static2() {
echo "B::static2\n";
}
}
B::staticA();
?>
As far as current userland code impact, there is very little as far as I
can tell. No keywords have been added, just another use for an existing
one. No changes were made to self:: or parent:: so the change should be
pretty transparent. The only thing that I see remotely causing any
issues would be the new function (get_caller_class().) I added that just
to complete the set so to speak.
----------
Mike Lively (ds- on irc.efnet.org)
"Our Schwartz is bigger than yours"
diff -Naur php-src/tests/classes/caller_001.phpt php-src-new/tests/classes/caller_001.phpt
--- php-src/tests/classes/caller_001.phpt 1969-12-31 16:00:00.000000000 -0800
+++ php-src-new/tests/classes/caller_001.phpt 2006-02-23 09:22:14.000000000 -0800
@@ -0,0 +1,61 @@
+--TEST--
+ZE2 Late Static Binding in a static function
+--FILE--
+<?php
+
+class TestClass {
+ protected static $staticVar = 'TestClassStatic';
+ const CLASS_CONST = 'TestClassConst';
+
+ protected static function staticFunction() {
+ return 'TestClassFunction';
+ }
+
+ public static function testStaticVar() {
+ return static::$staticVar;
+ }
+
+ public static function testClassConst() {
+ return static::CLASS_CONST;
+ }
+
+ public static function testStaticFunction() {
+ return static::staticFunction();
+ }
+}
+
+class ChildClass1 extends TestClass {
+ protected static $staticVar = 'ChildClassStatic';
+ const CLASS_CONST = 'ChildClassConst';
+
+ protected static function staticFunction() {
+ return 'ChildClassFunction';
+ }
+}
+
+class ChildClass2 extends TestClass {}
+
+echo TestClass::testStaticVar() . "\n";
+echo TestClass::testClassConst() . "\n";
+echo TestClass::testStaticFunction() . "\n";
+
+echo ChildClass1::testStaticVar() . "\n";
+echo ChildClass1::testClassConst() . "\n";
+echo ChildClass1::testStaticFunction() . "\n";
+
+echo ChildClass2::testStaticVar() . "\n";
+echo ChildClass2::testClassConst() . "\n";
+echo ChildClass2::testStaticFunction() . "\n";
+?>
+==DONE==
+--EXPECTF--
+TestClassStatic
+TestClassConst
+TestClassFunction
+ChildClassStatic
+ChildClassConst
+ChildClassFunction
+TestClassStatic
+TestClassConst
+TestClassFunction
+==DONE==
diff -Naur php-src/tests/classes/caller_002.phpt php-src-new/tests/classes/caller_002.phpt
--- php-src/tests/classes/caller_002.phpt 1969-12-31 16:00:00.000000000 -0800
+++ php-src-new/tests/classes/caller_002.phpt 2006-02-23 09:22:14.000000000 -0800
@@ -0,0 +1,66 @@
+--TEST--
+ZE2 Late Static Binding in an instance function
+--FILE--
+<?php
+
+class TestClass {
+ protected static $staticVar = 'TestClassStatic';
+ const CLASS_CONST = 'TestClassConst';
+
+ protected static function staticFunction() {
+ return 'TestClassFunction';
+ }
+
+ public function testStaticVar() {
+ return static::$staticVar;
+ }
+
+ public function testClassConst() {
+ return static::CLASS_CONST;
+ }
+
+ public function testStaticFunction() {
+ return static::staticFunction();
+ }
+}
+
+class ChildClass1 extends TestClass {
+ protected static $staticVar = 'ChildClassStatic';
+ const CLASS_CONST = 'ChildClassConst';
+
+ protected static function staticFunction() {
+ return 'ChildClassFunction';
+ }
+}
+
+class ChildClass2 extends TestClass {}
+
+$testClass = new TestClass();
+$childClass1 = new ChildClass1();
+$childClass2 = new ChildClass2();
+
+
+echo $testClass->testStaticVar() . "\n";
+echo $testClass->testClassConst() . "\n";
+echo $testClass->testStaticFunction() . "\n";
+
+echo $childClass1->testStaticVar() . "\n";
+echo $childClass1->testClassConst() . "\n";
+echo $childClass1->testStaticFunction() . "\n";
+
+echo $childClass2->testStaticVar() . "\n";
+echo $childClass2->testClassConst() . "\n";
+echo $childClass2->testStaticFunction() . "\n";
+?>
+==DONE==
+--EXPECTF--
+TestClassStatic
+TestClassConst
+TestClassFunction
+ChildClassStatic
+ChildClassConst
+ChildClassFunction
+TestClassStatic
+TestClassConst
+TestClassFunction
+==DONE==
diff -Naur php-src/tests/classes/caller_003.phpt php-src-new/tests/classes/caller_003.phpt
--- php-src/tests/classes/caller_003.phpt 1969-12-31 16:00:00.000000000 -0800
+++ php-src-new/tests/classes/caller_003.phpt 2006-02-23 09:22:14.000000000 -0800
@@ -0,0 +1,24 @@
+--TEST--
+ZE2 creating a new class with 'static'
+--FILE--
+<?php
+
+class TestClass {
+ public static function createInstance() {
+ return new static();
+ }
+}
+
+class ChildClass extends TestClass {}
+
+$testClass = TestClass::createInstance();
+$childClass = ChildClass::createInstance();
+
+echo get_class($testClass) . "\n";
+echo get_class($childClass) . "\n";
+?>
+==DONE==
+--EXPECTF--
+TestClass
+ChildClass
+==DONE==
diff -Naur php-src/tests/classes/caller_004.phpt php-src-new/tests/classes/caller_004.phpt
--- php-src/tests/classes/caller_004.phpt 1969-12-31 16:00:00.000000000 -0800
+++ php-src-new/tests/classes/caller_004.phpt 2006-02-23 09:22:14.000000000 -0800
@@ -0,0 +1,21 @@
+--TEST--
+ZE2 testing get_called_class()
+--FILE--
+<?php
+
+class TestClass {
+ public static function getClassName() {
+ return get_caller_class();
+ }
+}
+
+class ChildClass extends TestClass {}
+
+echo TestClass::getClassName() . "\n";
+echo ChildClass::getClassName() . "\n";
+?>
+==DONE==
+--EXPECTF--
+TestClass
+ChildClass
+==DONE==
diff -Naur php-src/tests/classes/caller_005.phpt php-src-new/tests/classes/caller_005.phpt
--- php-src/tests/classes/caller_005.phpt 1969-12-31 16:00:00.000000000 -0800
+++ php-src-new/tests/classes/caller_005.phpt 2006-02-23 09:22:14.000000000 -0800
@@ -0,0 +1,51 @@
+--TEST--
+ZE2 stacking static callers
+--FILE--
+<?php
+
+class TestA {
+ public static function test() {
+ echo get_class(new static()) . "\n";
+ TestB::test();
+ echo get_class(new static()) . "\n";
+ TestC::test();
+ echo get_class(new static()) . "\n";
+ TestBB::test();
+ echo get_class(new static()) . "\n";
+ }
+}
+
+class TestB {
+ public static function test() {
+ echo get_class(new static()) . "\n";
+ TestC::test();
+ echo get_class(new static()) . "\n";
+ }
+}
+
+class TestC {
+ public static function test() {
+ echo get_class(new static()) . "\n";
+ }
+}
+
+class TestBB extends TestB {
+}
+
+TestA::test();
+
+?>
+==DONE==
+--EXPECTF--
+TestA
+TestB
+TestC
+TestB
+TestA
+TestC
+TestA
+TestBB
+TestC
+TestBB
+TestA
+==DONE==
diff -Naur php-src/tests/classes/caller_006.phpt php-src-new/tests/classes/caller_006.phpt
--- php-src/tests/classes/caller_006.phpt 1969-12-31 16:00:00.000000000 -0800
+++ php-src-new/tests/classes/caller_006.phpt 2006-02-23 09:22:14.000000000 -0800
@@ -0,0 +1,12 @@
+--TEST--
+ZE2 ensuring extending 'static' is not allowed
+--FILE--
+<?php
+
+class Foo extends static {
+}
+
+?>
+==DONE==
+--EXPECTF--
+Fatal error: Cannot use 'static' as class name as it is reserved in %s on line %d
diff -Naur php-src/tests/classes/caller_007.phpt php-src-new/tests/classes/caller_007.phpt
--- php-src/tests/classes/caller_007.phpt 1969-12-31 16:00:00.000000000 -0800
+++ php-src-new/tests/classes/caller_007.phpt 2006-02-23 09:22:14.000000000 -0800
@@ -0,0 +1,12 @@
+--TEST--
+ZE2 ensuring implementing 'static' is not allowed
+--FILE--
+<?php
+
+class Foo implements static {
+}
+
+?>
+==DONE==
+--EXPECTF--
+Fatal error: Cannot use 'static' as interface name as it is reserved in %s on line %d
diff -Naur php-src/ZendEngine2/zend_builtin_functions.c php-src-new/ZendEngine2/zend_builtin_functions.c
--- php-src/ZendEngine2/zend_builtin_functions.c 2006-02-22 02:02:15.000000000 -0800
+++ php-src-new/ZendEngine2/zend_builtin_functions.c 2006-02-23 09:22:14.000000000 -0800
@@ -41,6 +41,7 @@
static ZEND_FUNCTION(define);
static ZEND_FUNCTION(defined);
static ZEND_FUNCTION(get_class);
+static ZEND_FUNCTION(get_caller_class);
static ZEND_FUNCTION(get_parent_class);
static ZEND_FUNCTION(method_exists);
static ZEND_FUNCTION(property_exists);
@@ -101,6 +102,7 @@
ZEND_FE(define, NULL)
ZEND_FE(defined, NULL)
ZEND_FE(get_class, NULL)
+ ZEND_FE(get_caller_class, NULL)
ZEND_FE(get_parent_class, NULL)
ZEND_FE(method_exists, NULL)
ZEND_FE(property_exists, NULL)
@@ -592,6 +594,22 @@
}
/* }}} */
+/* {{{ proto string get_caller_class()
+ Retrieves the class that was used to call a static function */
+ZEND_FUNCTION(get_caller_class)
+{
+ if (!ZEND_NUM_ARGS()) {
+ if (EG(active_op_array) && EG(active_op_array)->caller_scope) {
+ RETURN_TEXTL(EG(active_op_array)->caller_scope->name,
+ EG(active_op_array)->caller_scope->name_length, 1);
+ } else {
+ zend_error(E_ERROR, "get_caller_class() called from outside a class");
+ }
+ } else {
+ ZEND_WRONG_PARAM_COUNT();
+ }
+}
+/* }}} */
/* {{{ proto string get_parent_class([mixed object])
Retrieves the parent class name for object or class or current scope. */
diff -Naur php-src/ZendEngine2/zend_compile.c php-src-new/ZendEngine2/zend_compile.c
--- php-src/ZendEngine2/zend_compile.c 2006-02-22 02:56:52.000000000 -0800
+++ php-src-new/ZendEngine2/zend_compile.c 2006-02-23 09:22:14.000000000 -0800
@@ -1514,6 +1514,7 @@
switch (fetch_type) {
case ZEND_FETCH_CLASS_SELF:
case ZEND_FETCH_CLASS_PARENT:
+ case ZEND_FETCH_CLASS_STATIC:
SET_UNUSED(opline->op2);
opline->extended_value = fetch_type;
zval_dtor(&class_name->u.constant);
@@ -2835,7 +2836,9 @@
if ((lcname_len == sizeof("self")-1 &&
ZEND_U_EQUAL(Z_TYPE(class_name->u.constant), lcname, lcname_len, "self", sizeof("self")-1)) ||
(lcname_len == sizeof("parent")-1 &&
- ZEND_U_EQUAL(Z_TYPE(class_name->u.constant), lcname, lcname_len, "parent", sizeof("parent")-1))) {
+ ZEND_U_EQUAL(Z_TYPE(class_name->u.constant), lcname, lcname_len, "parent", sizeof("parent")-1)) ||
+ (lcname_len == sizeof("static")-1 &&
+ ZEND_U_EQUAL(Z_TYPE(class_name->u.constant), lcname, lcname_len, "static", sizeof("static")-1))) {
efree(lcname.v);
zend_error(E_COMPILE_ERROR, "Cannot use '%R' as class name as it is reserved", Z_TYPE(class_name->u.constant), Z_UNIVAL(class_name->u.constant));
}
@@ -2857,6 +2860,9 @@
case ZEND_FETCH_CLASS_PARENT:
zend_error(E_COMPILE_ERROR, "Cannot use 'parent' as class name as it is reserved");
break;
+ case ZEND_FETCH_CLASS_STATIC:
+ zend_error(E_COMPILE_ERROR, "Cannot use 'static' as class name as it is reserved");
+ break;
default:
break;
}
@@ -2966,6 +2972,9 @@
case ZEND_FETCH_CLASS_PARENT:
zend_error(E_COMPILE_ERROR, "Cannot use 'parent' as interface name as it is reserved");
break;
+ case ZEND_FETCH_CLASS_STATIC:
+ zend_error(E_COMPILE_ERROR, "Cannot use 'static' as interface name as it is reserved");
+ break;
default:
if (CG(active_op_array)->last > 0) {
opline = &CG(active_op_array)->opcodes[CG(active_op_array)->last-1];
@@ -4282,6 +4291,9 @@
} else if ((class_name_len == sizeof("parent")-1) &&
ZEND_U_EQUAL(type, class_name, class_name_len, "parent", sizeof("parent")-1)) {
return ZEND_FETCH_CLASS_PARENT;
+ } else if ((class_name_len == sizeof("static")-1) &&
+ ZEND_U_EQUAL(type, class_name, class_name_len, "static", sizeof("static")-1)) {
+ return ZEND_FETCH_CLASS_STATIC;
} else {
return ZEND_FETCH_CLASS_DEFAULT;
}
diff -Naur php-src/ZendEngine2/zend_compile.h php-src-new/ZendEngine2/zend_compile.h
--- php-src/ZendEngine2/zend_compile.h 2006-02-21 12:12:41.000000000 -0800
+++ php-src-new/ZendEngine2/zend_compile.h 2006-02-23 09:22:14.000000000 -0800
@@ -175,6 +175,7 @@
zend_uchar type;
zstr function_name;
zend_class_entry *scope;
+ zend_class_entry *caller_scope; /* to support late static binding */
zend_uint fn_flags;
union _zend_function *prototype;
zend_uint num_args;
@@ -229,6 +230,7 @@
zend_uchar type;
zstr function_name;
zend_class_entry *scope;
+ zend_class_entry *caller_scope; /* to support late static binding */
zend_uint fn_flags;
union _zend_function *prototype;
zend_uint num_args;
@@ -251,6 +253,7 @@
zend_uchar type; /* never used */
zstr function_name;
zend_class_entry *scope;
+ zend_class_entry *caller_scope; /* to support late static binding */
zend_uint fn_flags;
union _zend_function *prototype;
zend_uint num_args;
@@ -602,6 +605,7 @@
#define ZEND_FETCH_CLASS_GLOBAL 4
#define ZEND_FETCH_CLASS_AUTO 5
#define ZEND_FETCH_CLASS_INTERFACE 6
+#define ZEND_FETCH_CLASS_STATIC 7
#define ZEND_FETCH_CLASS_NO_AUTOLOAD 0x80
/* variable parsing type (compile-time) */
diff -Naur php-src/ZendEngine2/zend_execute_API.c php-src-new/ZendEngine2/zend_execute_API.c
--- php-src/ZendEngine2/zend_execute_API.c 2006-02-22 00:54:02.000000000 -0800
+++ php-src-new/ZendEngine2/zend_execute_API.c 2006-02-23 09:22:14.000000000 -0800
@@ -704,6 +704,16 @@
ce = &(EG(active_op_array)->scope->parent);
found = (*ce != NULL?SUCCESS:FAILURE);
fci->object_pp = EG(This)?&EG(This):NULL;
+ } else if (EG(active_op_array) &&
+ Z_UNILEN_PP(fci->object_pp) == sizeof("static")-1 &&
+ ZEND_U_EQUAL(Z_TYPE_PP(fci->object_pp), Z_UNIVAL_PP(fci->object_pp), Z_UNILEN_PP(fci->object_pp), "static", sizeof("static")-1)) {
+
+ if (!EG(active_op_array)->caller_scope) {
+ zend_error(E_ERROR, "Cannot access static:: when no called scope is active");
+ }
+ ce = &(EG(active_op_array)->caller_scope);
+ found = (*ce != NULL?SUCCESS:FAILURE);
+ fci->object_pp = EG(This)?&EG(This):NULL;
} else {
zend_class_entry *scope;
scope = EG(active_op_array) ? EG(active_op_array)->scope : NULL;
@@ -771,6 +781,9 @@
} else if (calling_scope && clen == sizeof("parent") - 1 &&
ZEND_U_EQUAL(Z_TYPE_P(fci->function_name), lcname, clen, "parent", sizeof("parent")-1)) {
ce_child = EG(active_op_array) && EG(active_op_array)->scope ? EG(scope)->parent : NULL;
+ } else if (calling_scope && clen == sizeof("static") - 1 &&
+ ZEND_U_EQUAL(Z_TYPE_P(fci->function_name), lcname, clen, "static", sizeof("static")-1)) {
+ ce_child = EG(active_op_array) && EG(active_op_array)->caller_scope ? EG(active_op_array)->caller_scope : NULL;
} else if (zend_u_lookup_class(Z_TYPE_P(fci->function_name), Z_UNIVAL_P(fci->function_name), clen, &pce TSRMLS_CC) == SUCCESS) {
ce_child = *pce;
}
@@ -1518,6 +1531,11 @@
zend_error(E_ERROR, "Cannot access parent:: when current class scope has no parent");
}
return EG(scope)->parent;
+ case ZEND_FETCH_CLASS_STATIC:
+ if (!EG(active_op_array) || !EG(active_op_array)->caller_scope) {
+ zend_error(E_ERROR, "Cannot access static:: when no called scope is active");
+ }
+ return EG(active_op_array)->caller_scope;
case ZEND_FETCH_CLASS_AUTO: {
fetch_type = zend_get_class_fetch_type(type, class_name, class_name_len);
if (fetch_type!=ZEND_FETCH_CLASS_DEFAULT) {
diff -Naur php-src/ZendEngine2/zend_language_parser.y php-src-new/ZendEngine2/zend_language_parser.y
--- php-src/ZendEngine2/zend_language_parser.y 2006-02-20 11:03:43.000000000 -0800
+++ php-src-new/ZendEngine2/zend_language_parser.y 2006-02-23 09:22:14.000000000 -0800
@@ -642,10 +642,12 @@
fully_qualified_class_name:
T_STRING { zend_do_fetch_class(&$$, &$1 TSRMLS_CC); }
+ | T_STATIC { znode static_string; static_string.op_type = IS_CONST; static_string.u.constant.type = IS_STRING; static_string.u.constant.value.str.val = (char *)estrndup("static", 6); static_string.u.constant.value.str.len = 6; zend_do_fetch_class(&$$, &static_string TSRMLS_CC); }
;
class_name_reference:
T_STRING { zend_do_fetch_class(&$$, &$1 TSRMLS_CC); }
+ | T_STATIC { znode static_string; static_string.op_type = IS_CONST; static_string.u.constant.type = IS_STRING; static_string.u.constant.value.str.val = (char *)estrndup("static", 6); static_string.u.constant.value.str.len = 6; zend_do_fetch_class(&$$, &static_string TSRMLS_CC); }
| dynamic_class_name_reference { zend_do_end_variable_parse(BP_VAR_R, 0 TSRMLS_CC); zend_do_fetch_class(&$$, &$1 TSRMLS_CC); }
;
diff -Naur php-src/ZendEngine2/zend_object_handlers.c php-src-new/ZendEngine2/zend_object_handlers.c
--- php-src/ZendEngine2/zend_object_handlers.c 2006-02-21 12:12:41.000000000 -0800
+++ php-src-new/ZendEngine2/zend_object_handlers.c 2006-02-23 09:22:14.000000000 -0800
@@ -756,6 +756,7 @@
call_user_call->arg_info = NULL;
call_user_call->num_args = 0;
call_user_call->scope = zobj->ce;
+ call_user_call->caller_scope = zobj->ce;
call_user_call->fn_flags = 0;
if (UG(unicode)) {
call_user_call->function_name.u = eustrndup(method_name.u, method_len);
@@ -772,6 +773,7 @@
}
/* Check access level */
+ fbc->op_array.caller_scope = zobj->ce;
if (fbc->op_array.fn_flags & ZEND_ACC_PUBLIC) {
/* Ensure that we haven't overridden a private function and end up calling
* the overriding public function...
@@ -830,6 +832,7 @@
zend_error(E_ERROR, "Cannot call non static method %v::%v() without object", ZEND_FN_SCOPE_NAME(fbc), fbc->common.function_name);
}
#endif
+ fbc->common.caller_scope = ce;
if (fbc->op_array.fn_flags & ZEND_ACC_PUBLIC) {
/* No further checks necessary, most common case */
} else if (fbc->op_array.fn_flags & ZEND_ACC_PRIVATE) {
diff -Naur php-src/ZendEngine2/zend_opcode.c php-src-new/ZendEngine2/zend_opcode.c
--- php-src/ZendEngine2/zend_opcode.c 2006-02-21 12:12:41.000000000 -0800
+++ php-src-new/ZendEngine2/zend_opcode.c 2006-02-23 09:22:14.000000000 -0800
@@ -86,6 +86,7 @@
op_array->required_num_args = 0;
op_array->scope = NULL;
+ op_array->caller_scope = NULL;
op_array->brk_cont_array = NULL;
op_array->try_catch_array = NULL;
--
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