From cd37ab8a16ba70cc005a333fdfa4c0620f474fbb Mon Sep 17 00:00:00 2001
From: Benjamin Eberlei <kontakt@beberlei.de>
Date: Mon, 29 Nov 2021 11:00:58 +0100
Subject: [PATCH] Workaround for PHP bug 84130:
 https://bugs.php.net/bug.php?id=81430

---
 tests/php_bug_84130.phpt | 61 ++++++++++++++++++++++++++++++++++++++++
 tideways_xhprof.c        | 21 ++++++++++++++
 2 files changed, 82 insertions(+)
 create mode 100644 tests/php_bug_84130.phpt

diff --git a/tests/php_bug_84130.phpt b/tests/php_bug_84130.phpt
new file mode 100644
index 0000000..394349c
--- /dev/null
+++ b/tests/php_bug_84130.phpt
@@ -0,0 +1,61 @@
+--TEST--
+Workaround for PHP Bug #81430
+--SKIPIF--
+<?php
+if (PHP_VERSION_ID < 80000) {
+    echo "skip requires 8 due to attributes";
+}
+--FILE--
+<?php
+include __DIR__ . "/common.php";
+
+#[\Attribute]
+class A {
+    private $foo;
+    public function __construct($foo)
+    {
+        $this->foo = $foo;
+    }
+}
+
+#[A("baz")]
+class B {
+    public function getBar($input) { return $input * 2; }
+}
+
+#[A("bar")]
+function B() {}
+
+tideways_xhprof_enable();
+
+$foo = new A("foo");
+
+$b = new B();
+var_dump($b->getBar(4));
+
+$r = new \ReflectionFunction("B");
+var_dump($r->getAttributes(A::class)[0]->newInstance());
+var_dump(call_user_func([$r->getAttributes(A::class)[0], 'newInstance']));
+
+$output = tideways_xhprof_disable();
+
+print_canonical($output);
+--EXPECTF--
+int(8)
+object(A)#5 (1) {
+  ["foo":"A":private]=>
+  string(3) "bar"
+}
+object(A)#4 (1) {
+  ["foo":"A":private]=>
+  string(3) "bar"
+}
+call_user_func==>ReflectionAttribute::newInstance: ct=       1; wt=*;
+main()                                  : ct=       1; wt=*;
+main()==>B::getBar                      : ct=       1; wt=*;
+main()==>ReflectionAttribute::newInstance: ct=       1; wt=*;
+main()==>ReflectionFunction::__construct: ct=       1; wt=*;
+main()==>ReflectionFunctionAbstract::getAttributes: ct=       2; wt=*;
+main()==>call_user_func                 : ct=       1; wt=*;
+main()==>tideways_xhprof_disable        : ct=       1; wt=*;
+main()==>var_dump                       : ct=       3; wt=*;
diff --git a/tideways_xhprof.c b/tideways_xhprof.c
index 66e55bd..8487a36 100644
--- a/tideways_xhprof.c
+++ b/tideways_xhprof.c
@@ -26,6 +26,7 @@ ZEND_DLEXPORT void tideways_xhprof_execute_internal(zend_execute_data *execute_d
 
 #if PHP_VERSION_ID >= 80000
 #include "zend_observer.h"
+#include "Zend/zend_attributes.h"
 
 static void tracer_observer_begin(zend_execute_data *ex) {
     if (!TXRG(enabled)) {
@@ -49,6 +50,26 @@ static void tracer_observer_end(zend_execute_data *ex, zval *return_value) {
 static zend_observer_fcall_handlers tracer_observer(zend_execute_data *execute_data) {
     zend_function *func = execute_data->func;
 
+    if (func->common.scope != NULL &&
+        func->common.scope->attributes != NULL &&
+        zend_get_attribute_str(func->common.scope->attributes, "attribute", sizeof("attribute")-1) != NULL) {
+        /*
+         * This condition is a workaround for PHP bug #81430
+         * (https://bugs.php.net/bug.php?id=81430) which was introduced in PHP
+         * 8.0.12. We created a pull request
+         * (https://github.com/php/php-src/pull/7665) which will hopefully be
+         * merged and fix this bug in PHP 8.0.14.
+         *
+         * In PHP 8.0.12 a new check was introduced to
+         * zend_observer_fcall_end() which expects the run_time_cache of
+         * functions to be properly initialized. However, there are dummy
+         * frames where the run_time_cache__ptr is simply NULL, so where the
+         * cache is not properly initialized. This condition ensures that
+         * attribute based dummy frames have no observers.
+         */
+        return (zend_observer_fcall_handlers) {NULL, NULL};
+    }
+
     if (!func->common.function_name) {
         return (zend_observer_fcall_handlers){NULL, NULL};
     }