[DRAFT] [WIP] Initial zend_class_alias

Zend/Optimizer/zend_optimizer.c

@@ -30,6 +30,7 @@
 #include "zend_call_graph.h"
 #include "zend_inference.h"
 #include "zend_dump.h"
+#include "zend_class_alias.h"
 #include "php.h"
 
 #ifndef ZEND_OPTIMIZER_MAX_REGISTERED_PASSES
@@ -773,7 +774,8 @@ void zend_optimizer_shift_jump(zend_op_array *op_array, zend_op *opline, uint32_
 
 static bool zend_optimizer_ignore_class(zval *ce_zv, zend_string *filename)
 {
-	zend_class_entry *ce = Z_PTR_P(ce_zv);
+	zend_class_entry *ce;
+	Z_CE_FROM_ZVAL_P(ce, ce_zv);
 
 	if (ce->ce_flags & ZEND_ACC_PRELOADED) {
 		Bucket *ce_bucket = (Bucket*)((uintptr_t)ce_zv - XtOffsetOf(Bucket, val));
@@ -809,14 +811,22 @@ static bool zend_optimizer_ignore_function(zval *fbc_zv, zend_string *filename)
 
 zend_class_entry *zend_optimizer_get_class_entry(
 		const zend_script *script, const zend_op_array *op_array, zend_string *lcname) {
-	zend_class_entry *ce = script ? zend_hash_find_ptr(&script->class_table, lcname) : NULL;
-	if (ce) {
-		return ce;
+	zval *ce_or_alias = script ? zend_hash_find(&script->class_table, lcname) : NULL;
+	if (ce_or_alias) {
+		if (EXPECTED(Z_TYPE_P(ce_or_alias) == IS_PTR)) {
+			return Z_PTR_P(ce_or_alias);
+		}
+		ZEND_ASSERT(Z_TYPE_P(ce_or_alias) == IS_ALIAS_PTR);
+		return Z_CLASS_ALIAS_P(ce_or_alias)->ce;
 	}
 
 	zval *ce_zv = zend_hash_find(CG(class_table), lcname);
 	if (ce_zv && !zend_optimizer_ignore_class(ce_zv, op_array ? op_array->filename : NULL)) {
-		return Z_PTR_P(ce_zv);
+		if (EXPECTED(Z_TYPE_P(ce_zv) == IS_PTR)) {
+			return Z_PTR_P(ce_zv);
+		}
+		ZEND_ASSERT(Z_TYPE_P(ce_zv) == IS_ALIAS_PTR);
+		return Z_CLASS_ALIAS_P(ce_zv)->ce;
 	}
 
 	if (op_array && op_array->scope && zend_string_equals_ci(op_array->scope->name, lcname)) {

Zend/tests/attributes/034_target_values.phpt

@@ -16,24 +16,26 @@ showFlag("TARGET_PROPERTY", Attribute::TARGET_PROPERTY);
 showFlag("TARGET_CLASS_CONSTANT", Attribute::TARGET_CLASS_CONSTANT);
 showFlag("TARGET_PARAMETER", Attribute::TARGET_PARAMETER);
 showFlag("TARGET_CONSTANT", Attribute::TARGET_CONSTANT);
+showFlag("TARGET_CLASS_ALIAS", Attribute::TARGET_CLASS_ALIAS);
 showFlag("IS_REPEATABLE", Attribute::IS_REPEATABLE);
 
 $all = Attribute::TARGET_CLASS | Attribute::TARGET_FUNCTION
     | Attribute::TARGET_METHOD | Attribute::TARGET_PROPERTY
     | Attribute::TARGET_CLASS_CONSTANT | Attribute::TARGET_PARAMETER
-    | Attribute::TARGET_CONSTANT;
+    | Attribute::TARGET_CONSTANT | Attribute::TARGET_CLASS_ALIAS;
 var_dump($all, Attribute::TARGET_ALL, $all === Attribute::TARGET_ALL);
 
 ?>
 --EXPECT--
-Attribute::TARGET_CLASS = 1 (127 & 1 === 1)
-Attribute::TARGET_FUNCTION = 2 (127 & 2 === 2)
-Attribute::TARGET_METHOD = 4 (127 & 4 === 4)
-Attribute::TARGET_PROPERTY = 8 (127 & 8 === 8)
-Attribute::TARGET_CLASS_CONSTANT = 16 (127 & 16 === 16)
-Attribute::TARGET_PARAMETER = 32 (127 & 32 === 32)
-Attribute::TARGET_CONSTANT = 64 (127 & 64 === 64)
-Attribute::IS_REPEATABLE = 128 (127 & 128 === 0)
-int(127)
-int(127)
+Attribute::TARGET_CLASS = 1 (255 & 1 === 1)
+Attribute::TARGET_FUNCTION = 2 (255 & 2 === 2)
+Attribute::TARGET_METHOD = 4 (255 & 4 === 4)
+Attribute::TARGET_PROPERTY = 8 (255 & 8 === 8)
+Attribute::TARGET_CLASS_CONSTANT = 16 (255 & 16 === 16)
+Attribute::TARGET_PARAMETER = 32 (255 & 32 === 32)
+Attribute::TARGET_CONSTANT = 64 (255 & 64 === 64)
+Attribute::TARGET_CLASS_ALIAS = 128 (255 & 128 === 128)
+Attribute::IS_REPEATABLE = 256 (255 & 256 === 0)
+int(255)
+int(255)
 bool(true)

Zend/tests/attributes/class_alias/attributes_dict.phpt

@@ -0,0 +1,19 @@
+--TEST--
+Alias attributes must not be associative
+--FILE--
+<?php
+
+#[ClassAlias('Other', ['test' => new Deprecated()])]
+class Demo {}
+
+$attr = new ReflectionClass( Demo::class )->getAttributes()[0];
+$attr->newInstance();
+
+?>
+--EXPECTF--
+Fatal error: Uncaught Error: ClassAlias::__construct(): Argument #2 ($attributes) must be a list, not an associative array in %s:%d
+Stack trace:
+#0 %s(%d): ClassAlias->__construct('Other', Array)
+#1 %s(%d): ReflectionAttribute->newInstance()
+#2 {main}
+  thrown in %s on line %d

Zend/tests/attributes/class_alias/attributes_nonarray.phpt

@@ -0,0 +1,14 @@
+--TEST--
+Alias attributes must be an array
+--FILE--
+<?php
+
+#[ClassAlias('Other', true)]
+class Demo {}
+
+$attr = new ReflectionClass( Demo::class )->getAttributes()[0];
+$attr->newInstance();
+
+?>
+--EXPECTF--
+Fatal error: ClassAlias::__construct(): Argument #2 ($attributes) must be of type array, true given in %s on line %d

Zend/tests/attributes/class_alias/attributes_valid.phpt

@@ -0,0 +1,12 @@
+--TEST--
+Alias attributes do not need to exist for declaration
+--FILE--
+<?php
+
+#[ClassAlias('Other', [new MissingAttribute()])]
+class Demo {}
+
+echo "Done\n"
+?>
+--EXPECT--
+Done

Zend/tests/attributes/class_alias/name_invalid.phpt

@@ -0,0 +1,11 @@
+--TEST--
+Alias name must be valid
+--FILE--
+<?php
+
+#[ClassAlias('never')]
+class Demo {}
+
+?>
+--EXPECTF--
+Fatal error: Cannot use "never" as a class alias as it is reserved in %s on line %d

Zend/tests/attributes/class_alias/name_nonstring.phpt

@@ -0,0 +1,11 @@
+--TEST--
+Parameter must be a string
+--FILE--
+<?php
+
+#[ClassAlias([])]
+class Demo {}
+
+?>
+--EXPECTF--
+Fatal error: ClassAlias::__construct(): Argument #1 ($alias) must be of type string, array given in %s on line %d

Zend/tests/attributes/class_alias/name_required.phpt

@@ -0,0 +1,15 @@
+--TEST--
+Parameter is required
+--FILE--
+<?php
+
+#[ClassAlias]
+class Demo {}
+
+?>
+--EXPECTF--
+Fatal error: Uncaught ArgumentCountError: ClassAlias::__construct() expects at least 1 argument, 0 given in %s:%d
+Stack trace:
+#0 %s(%d): ClassAlias->__construct()
+#1 {main}
+  thrown in %s on line %d

Zend/tests/attributes/class_alias/redeclaration_error.phpt

@@ -0,0 +1,11 @@
+--TEST--
+Cannot redeclare an existing class
+--FILE--
+<?php
+
+#[ClassAlias('Attribute')]
+class Demo {}
+
+?>
+--EXPECTF--
+Fatal error: Unable to declare alias 'Attribute' for 'Demo' in %s on line %d

Zend/tests/attributes/class_alias/repeated_attribute.phpt

@@ -0,0 +1,25 @@
+--TEST--
+Attribute can be repeated
+--FILE--
+<?php
+
+#[ClassAlias('First')]
+#[ClassAlias('Second')]
+class Demo {}
+
+var_dump( class_exists( 'First' ) );
+var_dump( class_exists( 'Second' ) );
+
+$obj1 = new First();
+var_dump( $obj1 );
+
+$obj2 = new Second();
+var_dump( $obj2 );
+?>
+--EXPECTF--
+bool(true)
+bool(true)
+object(Demo)#%d (0) {
+}
+object(Demo)#%d (0) {
+}

Zend/tests/attributes/class_alias/target_validation.phpt

@@ -0,0 +1,11 @@
+--TEST--
+Can only be used on classes
+--FILE--
+<?php
+
+#[ClassAlias]
+function demo() {}
+
+?>
+--EXPECTF--
+Fatal error: Attribute "ClassAlias" cannot target function (allowed targets: class) in %s on line %d

Zend/tests/attributes/class_alias/working_example.phpt

@@ -0,0 +1,17 @@
+--TEST--
+Working usage
+--FILE--
+<?php
+
+#[ClassAlias('Other')]
+class Demo {}
+
+var_dump( class_exists( 'Other' ) );
+
+$obj = new Other();
+var_dump( $obj );
+?>
+--EXPECTF--
+bool(true)
+object(Demo)#%d (0) {
+}

Zend/tests/attributes/class_alias_target/class_alias_listed_as_target-internal.phpt

@@ -0,0 +1,11 @@
+--TEST--
+Class alias listed in valid targets when used wrong (internal attribute)
+--FILE--
+<?php
+
+#[Deprecated]
+class Example {}
+
+?>
+--EXPECTF--
+Fatal error: Attribute "Deprecated" cannot target class (allowed targets: function, method, class constant, constant, class alias) in %s on line %d

Zend/tests/attributes/class_alias_target/class_alias_listed_as_target-userland.phpt

@@ -0,0 +1,31 @@
+--TEST--
+Class alias listed in valid targets when used wrong (userland attribute)
+--FILE--
+<?php
+
+#[Attribute(Attribute::TARGET_CLASS_ALIAS)]
+class MyAliasAttribute {}
+
+#[MyAliasAttribute]
+class Example {}
+
+$ref = new ReflectionClass(Example::class);
+$attribs = $ref->getAttributes();
+var_dump($attribs);
+$attribs[0]->newInstance();
+
+?>
+--EXPECTF--
+array(1) {
+  [0]=>
+  object(ReflectionAttribute)#%d (1) {
+    ["name"]=>
+    string(16) "MyAliasAttribute"
+  }
+}
+
+Fatal error: Uncaught Error: Attribute "MyAliasAttribute" cannot target class (allowed targets: class alias) in %s:%d
+Stack trace:
+#0 %s(%d): ReflectionAttribute->newInstance()
+#1 {main}
+  thrown in %s on line %d

Zend/tests/attributes/class_alias_target/must_target_class_alias-internal.phpt

@@ -0,0 +1,11 @@
+--TEST--
+Error when attribute does not target class alias (internal attribute)
+--FILE--
+<?php
+
+#[ClassAlias('Other', [new Override()])]
+class Demo {}
+
+?>
+--EXPECTF--
+Fatal error: Attribute "Override" cannot target class alias (allowed targets: method) in %s on line %d

Zend/tests/attributes/class_alias_target/must_target_class_alias-userland.phpt

@@ -0,0 +1,31 @@
+--TEST--
+Error when attribute does not target class alias (useland attribute)
+--FILE--
+<?php
+
+#[Attribute(Attribute::TARGET_FUNCTION)]
+class MyFunctionAttribute {}
+
+#[ClassAlias('Other', [new MyFunctionAttribute()])]
+class Demo {}
+
+$ref = new ReflectionClassAlias('Other');
+$attribs = $ref->getAttributes();
+var_dump($attribs);
+$attribs[0]->newInstance();
+
+?>
+--EXPECTF--
+array(1) {
+  [0]=>
+  object(ReflectionAttribute)#%d (1) {
+    ["name"]=>
+    string(19) "MyFunctionAttribute"
+  }
+}
+
+Fatal error: Uncaught Error: Attribute "MyFunctionAttribute" cannot target class alias (allowed targets: function) in %s:%d
+Stack trace:
+#0 %s(%d): ReflectionAttribute->newInstance()
+#1 {main}
+  thrown in %s on line %d

Zend/tests/attributes/class_alias_target/not_repeatable-internal.phpt

@@ -0,0 +1,11 @@
+--TEST--
+Validation of attribute repetition (not allowed; internal attribute)
+--FILE--
+<?php
+
+#[ClassAlias('Other', [new Deprecated(), new Deprecated()])]
+class Demo {}
+
+?>
+--EXPECTF--
+Fatal error: Attribute "Deprecated" must not be repeated in %s on line %d

Zend/tests/attributes/class_alias_target/not_repeatable-userland.phpt

@@ -0,0 +1,35 @@
+--TEST--
+Validation of attribute repetition (not allowed; userland attribute)
+--FILE--
+<?php
+
+#[Attribute]
+class MyAttribute {}
+
+#[ClassAlias('Other', [new MyAttribute(), new MyAttribute()])]
+class Demo {}
+
+$attributes = new ReflectionClassAlias('Other')->getAttributes();
+var_dump($attributes);
+$attributes[0]->newInstance();
+
+?>
+--EXPECTF--
+array(2) {
+  [0]=>
+  object(ReflectionAttribute)#%d (1) {
+    ["name"]=>
+    string(11) "MyAttribute"
+  }
+  [1]=>
+  object(ReflectionAttribute)#%d (1) {
+    ["name"]=>
+    string(11) "MyAttribute"
+  }
+}
+
+Fatal error: Uncaught Error: Attribute "MyAttribute" must not be repeated in %s:%d
+Stack trace:
+#0 %s(%d): ReflectionAttribute->newInstance()
+#1 {main}
+  thrown in %s on line %d

Zend/tests/attributes/class_alias_target/repeatable-internal.phpt

@@ -0,0 +1,15 @@
+--TEST--
+Validation of attribute repetition (is allowed; internal attribute)
+--EXTENSIONS--
+zend_test
+--FILE--
+<?php
+
+#[ClassAlias('Other', [new ZendTestRepeatableAttribute(), new ZendTestRepeatableAttribute()])]
+class Demo {}
+
+echo "Done\n";
+
+?>
+--EXPECT--
+Done