[k2] fix coro frame alignment

compiler/compiler-settings.cpp

@@ -340,6 +340,11 @@ void CompilerSettings::init() {
     if (!dynamic_incremental_linkage.get()) {
       ss << " -fvisibility=hidden";
     }
+    if (vk::contains(cxx.get(), "clang")) {
+      // To avoid undefined behavior, the coroutine frame must be allocated using the aligned operator new overload (the one that takes a std::align_val_t)
+      // Details: https://github.com/llvm/llvm-project/commit/327141fb1d8ca35b323107a43d57886eb77e7384
+      ss << " -fcoro-aligned-allocation";
+    }
     // Temporary solution. Required for allocator functions replacement in timelib
     ss << " -DTIMELIB_ALLOC_FUNC_PREFIX=timelib_";
   } else {

runtime-light/coroutine/detail/await-set.h

@@ -61,6 +61,11 @@ class await_broker {
     return kphp::memory::script::alloc(n);
   }
 
+  template<typename... Args>
+  auto operator new(size_t n, std::align_val_t al, [[maybe_unused]] Args&&... args) noexcept -> void* {
+    return kphp::memory::script::alloc_aligned(n, al);
+  }
+
   void operator delete(void* ptr, [[maybe_unused]] size_t n) noexcept {
     kphp::memory::script::free(ptr);
   }
@@ -168,6 +173,11 @@ class await_set_task_promise_base : public kphp::coro::async_stack_element {
     return kphp::memory::script::alloc(n);
   }
 
+  template<typename... Args>
+  auto operator new(size_t n, std::align_val_t al, [[maybe_unused]] Args&&... args) noexcept -> void* {
+    return kphp::memory::script::alloc_aligned(n, al);
+  }
+
   void operator delete(void* ptr, [[maybe_unused]] size_t n) noexcept {
     kphp::memory::script::free(ptr);
   }

runtime-light/coroutine/detail/task-self-deleting.h

@@ -35,6 +35,11 @@ struct promise_self_deleting : kphp::coro::async_stack_element {
     return kphp::memory::script::alloc(n);
   }
 
+  template<typename... Args>
+  auto operator new(size_t n, std::align_val_t al, [[maybe_unused]] Args&&... args) noexcept -> void* {
+    return kphp::memory::script::alloc_aligned(n, al);
+  }
+
   auto operator delete(void* ptr, [[maybe_unused]] size_t n) noexcept -> void {
     kphp::memory::script::free(ptr);
   }

runtime-light/coroutine/detail/when-all.h

@@ -155,6 +155,11 @@ class when_all_task_promise_base : public kphp::coro::async_stack_element {
     return kphp::memory::script::alloc(n);
   }
 
+  template<typename... Args>
+  auto operator new(size_t n, std::align_val_t al, [[maybe_unused]] Args&&... args) noexcept -> void* {
+    return kphp::memory::script::alloc_aligned(n, al);
+  }
+
   auto operator delete(void* ptr, [[maybe_unused]] size_t n) noexcept -> void {
     kphp::memory::script::free(ptr);
   }

runtime-light/coroutine/detail/when-any.h

@@ -165,6 +165,11 @@ class when_any_task_promise_base : public kphp::coro::async_stack_element {
     return kphp::memory::script::alloc(n);
   }
 
+  template<typename... Args>
+  auto operator new(size_t n, std::align_val_t al, [[maybe_unused]] Args&&... args) noexcept -> void* {
+    return kphp::memory::script::alloc_aligned(n, al);
+  }
+
   auto operator delete(void* ptr, [[maybe_unused]] size_t n) noexcept -> void {
     kphp::memory::script::free(ptr);
   }

runtime-light/coroutine/shared-task.h

@@ -148,6 +148,11 @@ struct promise_base : kphp::coro::async_stack_element {
     return kphp::memory::script::alloc(n);
   }
 
+  template<typename... Args>
+  auto operator new(size_t n, std::align_val_t al, [[maybe_unused]] Args&&... args) noexcept -> void* {
+    return kphp::memory::script::alloc_aligned(n, al);
+  }
+
   auto operator delete(void* ptr, [[maybe_unused]] size_t n) noexcept -> void {
     kphp::memory::script::free(ptr);
   }

runtime-light/coroutine/task.h

@@ -69,6 +69,11 @@ struct promise_base : kphp::coro::async_stack_element {
     return kphp::memory::script::alloc(n);
   }
 
+  template<typename... Args>
+  auto operator new(size_t n, std::align_val_t al, [[maybe_unused]] Args&&... args) noexcept -> void* {
+    return kphp::memory::script::alloc_aligned(n, al);
+  }
+
   auto operator delete(void* ptr, [[maybe_unused]] size_t n) noexcept -> void {
     kphp::memory::script::free(ptr);
   }

runtime-light/runtime-light.cmake

@@ -2,7 +2,7 @@ include(${THIRD_PARTY_DIR}/pcre2-cmake/pcre2.cmake)
 
 # =================================================================================================
 
-set(RUNTIME_LIGHT_COMPILE_FLAGS -stdlib=libc++ ${RUNTIME_LIGHT_VISIBILITY})
+set(RUNTIME_LIGHT_COMPILE_FLAGS -stdlib=libc++ -fcoro-aligned-allocation ${RUNTIME_LIGHT_VISIBILITY})
 
 set(RUNTIME_LIGHT_PLATFORM_SPECIFIC_LINK_FLAGS)
 if(APPLE)

tests/phpt/fork/043_sched_yield_in_callback.php

@@ -0,0 +1,21 @@
+@ok
+<?php
+require_once 'kphp_tester_include.php';
+
+/**
+ * @kphp-required
+ * @param int $a
+ * @param int $b
+ * @return int
+ */
+function cmp(int $a, int $b) {
+#ifndef KPHP
+  sched_yield();
+#endif
+  return $b - $a;
+}
+function main() {
+  $arr = [3, 2, 1];
+  uasort($arr, 'cmp');
+}
+main();