feat(zend, opcache, reflection): bound checks and parametric substitution for generics

Signed-off-by: azjezz <[email protected]>

Author: azjezz

Zend/Optimizer/optimize_func_calls.c

@@ -74,6 +74,46 @@ static void zend_delete_call_instructions(const zend_op_array *op_array, zend_op
 	}
 }
 
+/* Returns true if a VERIFY_GENERIC_ARGUMENTS sits between this call's INIT and
+ * DO opcodes; such a call cannot be inlined because the verify opcode reads
+ * EX(call), which goes away once the frame is dropped. */
+static bool zend_call_has_generic_arguments_check(zend_op *opline)
+{
+	int call = 0;
+	while (1) {
+		switch (opline->opcode) {
+			case ZEND_INIT_FCALL_BY_NAME:
+			case ZEND_INIT_NS_FCALL_BY_NAME:
+			case ZEND_INIT_STATIC_METHOD_CALL:
+			case ZEND_INIT_METHOD_CALL:
+			case ZEND_INIT_FCALL:
+			case ZEND_INIT_PARENT_PROPERTY_HOOK_CALL:
+				if (call == 0) {
+					return false;
+				}
+				ZEND_FALLTHROUGH;
+			case ZEND_NEW:
+			case ZEND_INIT_DYNAMIC_CALL:
+			case ZEND_INIT_USER_CALL:
+				call--;
+				break;
+			case ZEND_DO_FCALL:
+			case ZEND_DO_ICALL:
+			case ZEND_DO_UCALL:
+			case ZEND_DO_FCALL_BY_NAME:
+				call++;
+				break;
+			case ZEND_VERIFY_GENERIC_ARGUMENTS:
+				if (call == 0) {
+					return true;
+				}
+				break;
+		}
+
+		opline--;
+	}
+}
+
 static void zend_try_inline_call(zend_op_array *op_array, const zend_op *fcall, zend_op *opline, const zend_function *func)
 {
 	const uint32_t no_discard = RETURN_VALUE_USED(opline) ? 0 : ZEND_ACC_NODISCARD;
@@ -97,6 +137,11 @@ static void zend_try_inline_call(zend_op_array *op_array, const zend_op *fcall,
 				return;
 			}
 
+			if (zend_call_has_generic_arguments_check(opline - 1)) {
+				/* The verify opcode must run; inlining would orphan it. */
+				return;
+			}
+
 			for (i = 0; i < num_args; i++) {
 				/* Don't inline functions with by-reference arguments. This would require
 				 * correct handling of INDIRECT arguments. */

Zend/tests/generics/declaration/default_satisfies_bound.phpt

@@ -0,0 +1,18 @@
+--TEST--
+Declaration: type-parameter default that satisfies its bound is accepted
+--FILE--
+<?php
+class A {}
+class B extends A {}
+
+class Box<T : A = B> {}
+function f<T : A = B>(): void {}
+trait Tr<T : A = B> {}
+interface I<T : A = B> {}
+
+new Box;
+f();
+echo "OK\n";
+?>
+--EXPECT--
+OK

Zend/tests/generics/declaration/default_violates_bound_class.phpt

@@ -0,0 +1,9 @@
+--TEST--
+Declaration: class type-parameter default that does not satisfy its bound is rejected
+--FILE--
+<?php
+class Animal {}
+class Box<T : Animal = int> {}
+?>
+--EXPECTF--
+Fatal error: Default int for type parameter T does not satisfy its bound Animal in %s on line %d

Zend/tests/generics/declaration/default_violates_bound_function.phpt

@@ -0,0 +1,9 @@
+--TEST--
+Declaration: function type-parameter default that does not satisfy its bound is rejected
+--FILE--
+<?php
+class Animal {}
+function id<T : Animal = int>(): void {}
+?>
+--EXPECTF--
+Fatal error: Default int for type parameter T does not satisfy its bound Animal in %s on line %d

Zend/tests/generics/declaration/default_violates_bound_interface.phpt

@@ -0,0 +1,9 @@
+--TEST--
+Declaration: interface type-parameter default that does not satisfy its bound is rejected
+--FILE--
+<?php
+class Animal {}
+interface I<T : Animal = int> {}
+?>
+--EXPECTF--
+Fatal error: Default int for type parameter T does not satisfy its bound Animal in %s on line %d

Zend/tests/generics/declaration/default_violates_bound_trait.phpt

@@ -0,0 +1,9 @@
+--TEST--
+Declaration: trait type-parameter default that does not satisfy its bound is rejected
+--FILE--
+<?php
+class Animal {}
+trait Holder<T : Animal = int> {}
+?>
+--EXPECTF--
+Fatal error: Default int for type parameter T does not satisfy its bound Animal in %s on line %d

Zend/tests/generics/declaration/default_with_intersection_bound.phpt

@@ -0,0 +1,8 @@
+--TEST--
+Declaration: default checked against intersection bound when types are concrete
+--FILE--
+<?php
+class Box<T : Traversable & Countable = int> {}
+?>
+--EXPECTF--
+Fatal error: Default int for type parameter T does not satisfy its bound Traversable&Countable in %s on line %d

Zend/tests/generics/declaration/default_with_union_bound.phpt

@@ -0,0 +1,8 @@
+--TEST--
+Declaration: default checked against union bound when types are concrete
+--FILE--
+<?php
+class Box<T : int | string = float> {}
+?>
+--EXPECTF--
+Fatal error: Default float for type parameter T does not satisfy its bound string|int in %s on line %d

Zend/tests/generics/declaration/error_renders_default_args.phpt

@@ -0,0 +1,9 @@
+--TEST--
+Bound error message: declaration-time default-vs-bound error renders NAMED_WITH_ARGS in the bound
+--FILE--
+<?php
+interface Comparable<T> {}
+class Box<T : Comparable<T> = int> {}
+?>
+--EXPECTF--
+Fatal error: Default int for type parameter T does not satisfy its bound Comparable<T> in %s on line %d

Zend/tests/generics/inheritance/bounds/bound_on_bound_pass.phpt

@@ -0,0 +1,18 @@
+--TEST--
+Bound check: forwarded T-ref where child's bound is at least as tight as parent's
+--FILE--
+<?php
+class Animal {}
+class Dog extends Animal {}
+
+interface A<T : Animal> {}
+interface B<Y : Dog> extends A<Y> {}
+interface C<Z : Animal> extends A<Z> {}
+
+class IntBox<T : int> {}
+class IntSubBox<X : int> extends IntBox<X> {}
+
+echo "OK\n";
+?>
+--EXPECT--
+OK