test trampoline functions to ensure stability

Author: lavarou

tests/integration/lang/trampoline/test_trampoline_00.php

@@ -0,0 +1,39 @@
+<?php
+/*
+ * Copyright 2025 New Relic Corporation. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/*DESCRIPTION
+Test that trampoline functions not blow up.
+*/
+
+/*INI
+newrelic.code_level_metrics.enabled = true
+*/
+
+/*EXPECT_TRACED_ERRORS null*/
+
+/*EXPECT
+bool(false)
+*/
+
+class B {}
+class A extends B
+{
+  public function bar($func)
+  {
+    var_dump(is_callable(array('B', 'foo')));
+  }
+
+  public function __call($func, $args) {}
+}
+
+class X
+{
+  public static function __callStatic($func, $args) {}
+}
+
+$a = new A();
+// Extra X::foo() wrapper to force use of allocated trampoline.
+X::foo($a->bar('foo'));

tests/integration/lang/trampoline/test_trampoline_01.php

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+<?php
+/*
+ * Copyright 2025 New Relic Corporation. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/*DESCRIPTION
+Test that trampoline functions not blow up.
+*/
+
+/*INI
+newrelic.code_level_metrics.enabled = true
+*/
+
+/*EXPECT_METRICS_EXIST
+Custom/trampoline_factorial, 42
+*/
+
+/*EXPECT_TRACED_ERRORS null*/
+
+/*EXPECT
+ok - trampoline('trampoline_factorial', 42)
+*/
+
+require_once __DIR__ . '/../../../include/tap.php';
+
+newrelic_add_custom_tracer('trampoline_factorial');
+
+function trampoline_factorial($n, $acc = 1)
+{
+  if ($n == 1) {
+    return $acc;
+  }
+  return function () use ($n, $acc) {
+    return trampoline_factorial($n - 1, $n * $acc);
+  };
+}
+
+function trampoline(callable $c, ...$args)
+{
+  while (is_callable($c)) {
+    $c = $c(...$args);
+  }
+  return $c;
+}
+
+tap_equal(1.4050061177528801E+51, trampoline('trampoline_factorial', 42), "trampoline('trampoline_factorial', 42)");

tests/integration/lang/trampoline/test_trampoline_02.php

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+<?php
+/*
+ * Copyright 2025 New Relic Corporation. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/*DESCRIPTION
+Test that trampoline functions not blow up.
+*/
+
+/*INI
+newrelic.code_level_metrics.enabled = true
+*/
+
+/*EXPECT_METRICS_EXIST
+Custom/class@anonymous::execute, 2
+*/
+
+/*EXPECT_SPAN_EVENTS_LIKE
+[
+  [
+    {
+      "category": "generic",
+      "type": "Span",
+      "guid": "??",
+      "traceId": "??",
+      "transactionId": "??",
+      "name": "Custom\/class@anonymous::execute",
+      "timestamp": "??",
+      "duration": "??",
+      "priority": "??",
+      "sampled": true,
+      "parentId": "??"
+    },
+    {},
+    {
+      "code.lineno": "??",
+      "code.namespace": "class@anonymous",
+      "code.filepath": "__FILE__",
+      "code.function": "execute"
+    }
+  ],
+  [
+    {
+      "category": "generic",
+      "type": "Span",
+      "guid": "??",
+      "traceId": "??",
+      "transactionId": "??",
+      "name": "Custom\/class@anonymous::execute",
+      "timestamp": "??",
+      "duration": "??",
+      "priority": "??",
+      "sampled": true,
+      "parentId": "??"
+    },
+    {},
+    {
+      "code.lineno": "??",
+      "code.namespace": "class@anonymous",
+      "code.filepath": "__FILE__",
+      "code.function": "execute"
+    }
+  ]
+]
+*/
+
+/*EXPECT_TRACED_ERRORS null*/
+
+$anon = new class() {
+  function execute()
+  {
+    new ReflectionClass('Wrapper');
+  }
+};
+
+$anon2 = new class() {
+  function execute()
+  {
+    new ReflectionClass('Wrapper');
+  }
+};
+
+$klass = new ReflectionClass($anon);
+$method = $klass->getMethod('execute');
+$klass_name = $klass->getName();
+$method_name = $method->getName();
+
+newrelic_add_custom_tracer("$klass_name::$method_name");
+
+(new Wrapper($anon))->execute(
+  (new Wrapper($anon))->execute()
+);
+
+class Wrapper
+{
+  protected $wrapped;
+
+  function __construct($wrapped)
+  {
+    $this->wrapped = $wrapped;
+  }
+
+  public function __call($method, $arguments)
+  {
+    return call_user_func([$this->wrapped, $method]);
+  }
+}