[coroutines] Add support for coroutines with non-scalar parameters

Summary:
Simple types like int are handled by LLVM Coroutines just fine.
But for non-scalar parameters we need to create copies of those parameters in the coroutine frame and make all uses of those parameters to refer to parameter copies.

Reviewers: rsmith, EricWF, GorNishanov

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D33507

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@303803 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 95 insertions, 0 deletions

diff --git a/test/CodeGenCoroutines/coro-params.cpp b/test/CodeGenCoroutines/coro-params.cpp
new file mode 100644
index 0000000000..c88e503a65
--- /dev/null
+++ b/test/CodeGenCoroutines/coro-params.cpp
@@ -0,0 +1,95 @@
+// Verifies that parameters are copied with move constructors
+// Verifies that parameter copies are destroyed
+// Vefifies that parameter copies are used in the body of the coroutine
+// RUN: %clang_cc1 -std=c++1z -fcoroutines-ts -triple=x86_64-unknown-linux-gnu -emit-llvm -o - %s -disable-llvm-passes -fexceptions | FileCheck %s
+
+namespace std::experimental {
+template <typename... T> struct coroutine_traits;
+
+template <class Promise = void> struct coroutine_handle {
+  coroutine_handle() = default;
+  static coroutine_handle from_address(void *) noexcept;
+};
+template <> struct coroutine_handle<void> {
+  static coroutine_handle from_address(void *) noexcept;
+  coroutine_handle() = default;
+  template <class PromiseType>
+  coroutine_handle(coroutine_handle<PromiseType>) noexcept;
+};
+}
+
+struct suspend_always {
+  bool await_ready() noexcept;
+  void await_suspend(std::experimental::coroutine_handle<>) noexcept;
+  void await_resume() noexcept;
+};
+
+template <typename... Args> struct std::experimental::coroutine_traits<void, Args...> {
+  struct promise_type {
+    void get_return_object() noexcept;
+    suspend_always initial_suspend() noexcept;
+    suspend_always final_suspend() noexcept;
+    void return_void() noexcept;
+    promise_type();
+    ~promise_type() noexcept;
+    void unhandled_exception() noexcept;
+  };
+};
+
+// TODO: Not supported yet
+struct CopyOnly {
+  int val;
+  CopyOnly(const CopyOnly&) noexcept;
+  CopyOnly(CopyOnly&&) = delete;
+  ~CopyOnly();
+};
+
+struct MoveOnly {
+  int val;
+  MoveOnly(const MoveOnly&) = delete;
+  MoveOnly(MoveOnly&&) noexcept;
+  ~MoveOnly();
+};
+
+struct MoveAndCopy {
+  int val;
+  MoveAndCopy(const MoveAndCopy&)noexcept;
+  MoveAndCopy(MoveAndCopy&&) noexcept;
+  ~MoveAndCopy();
+};
+
+void consume(int,int,int) noexcept;
+
+// TODO: Add support for CopyOnly params
+// CHECK: define void @_Z1fi8MoveOnly11MoveAndCopy(i32 %val, %struct.MoveOnly* %[[MoParam:.+]], %struct.MoveAndCopy* %[[McParam:.+]]) #0 personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*
+void f(int val, MoveOnly moParam, MoveAndCopy mcParam) {
+  // CHECK: %[[MoCopy:.+]] = alloca %struct.MoveOnly
+  // CHECK: %[[McCopy:.+]] = alloca %struct.MoveAndCopy
+  // CHECK: store i32 %val, i32* %[[ValAddr:.+]]
+
+  // CHECK: call i8* @llvm.coro.begin(
+  // CHECK-NEXT: call void @_ZN8MoveOnlyC1EOS_(%struct.MoveOnly* %[[MoCopy]], %struct.MoveOnly* dereferenceable(4) %[[MoParam]])
+  // CHECK-NEXT: call void @_ZN11MoveAndCopyC1EOS_(%struct.MoveAndCopy* %[[McCopy]], %struct.MoveAndCopy* dereferenceable(4) %[[McParam]]) #
+  // CHECK-NEXT: invoke void @_ZNSt12experimental16coroutine_traitsIJvi8MoveOnly11MoveAndCopyEE12promise_typeC1Ev(
+
+  // CHECK: call void @_ZN14suspend_always12await_resumeEv(
+  // CHECK: %[[IntParam:.+]] = load i32, i32* %val.addr
+  // CHECK: %[[MoGep:.+]] = getelementptr inbounds %struct.MoveOnly, %struct.MoveOnly* %[[MoCopy]], i32 0, i32 0
+  // CHECK: %[[MoVal:.+]] = load i32, i32* %[[MoGep]]
+  // CHECK: %[[McGep:.+]] =  getelementptr inbounds %struct.MoveAndCopy, %struct.MoveAndCopy* %[[McCopy]], i32 0, i32 0
+  // CHECK: %[[McVal:.+]] = load i32, i32* %[[McGep]]
+  // CHECK: call void @_Z7consumeiii(i32 %[[IntParam]], i32 %[[MoVal]], i32 %[[McVal]])
+
+  consume(val, moParam.val, mcParam.val);
+  co_return;
+
+  // Skip to final suspend:
+  // CHECK: call void @_ZNSt12experimental16coroutine_traitsIJvi8MoveOnly11MoveAndCopyEE12promise_type13final_suspendEv(
+  // CHECK: call void @_ZN14suspend_always12await_resumeEv(
+
+  // Destroy promise, then parameter copies:
+  // CHECK: call void @_ZNSt12experimental16coroutine_traitsIJvi8MoveOnly11MoveAndCopyEE12promise_typeD1Ev(%"struct.std::experimental::coroutine_traits<void, int, MoveOnly, MoveAndCopy>::promise_type"* %__promise) #2
+  // CHECK-NEXT: call void @_ZN11MoveAndCopyD1Ev(%struct.MoveAndCopy* %[[McCopy]])
+  // CHECK-NEXT: call void @_ZN8MoveOnlyD1Ev(%struct.MoveOnly* %[[MoCopy]]
+  // CHECK-NEXT: call i8* @llvm.coro.free(
+}