GorNishanov created this revision.
If unhandled_exception member function is present in the coroutine promise,
wrap the body of the coroutine in:
try {
body
} catch(...) { promise.unhandled_exception(); }
https://reviews.llvm.org/D31692
Files:
include/clang/AST/StmtCXX.h
include/clang/Basic/DiagnosticSemaKinds.td
lib/AST/StmtCXX.cpp
lib/CodeGen/CGCoroutine.cpp
lib/Sema/SemaCoroutine.cpp
test/CodeGenCoroutines/coro-cleanup.cpp
test/SemaCXX/coroutine-seh.cpp
Index: test/SemaCXX/coroutine-seh.cpp
===================================================================
--- /dev/null
+++ test/SemaCXX/coroutine-seh.cpp
@@ -0,0 +1,37 @@
+// RUN: %clang_cc1 -std=c++1z -fcoroutines-ts -verify %s -fcxx-exceptions -fexceptions -triple x86_64-windows-msvc -fms-extensions
+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 <> struct std::experimental::coroutine_traits<void> {
+ struct promise_type {
+ void get_return_object() noexcept;
+ suspend_always initial_suspend() noexcept;
+ suspend_always final_suspend() noexcept;
+ void return_void() noexcept;
+ void unhandled_exception() noexcept;
+ };
+};
+
+void SEH_used() {
+ __try { // expected-error {{cannot use SEH '__try' in a coroutine when C++ exceptions are enabled}}
+ co_return; // expected-note {{function is a coroutine due to use of 'co_return' here}}
+ } __except(0) {}
+}
Index: test/CodeGenCoroutines/coro-cleanup.cpp
===================================================================
--- test/CodeGenCoroutines/coro-cleanup.cpp
+++ test/CodeGenCoroutines/coro-cleanup.cpp
@@ -6,38 +6,38 @@
template <class Promise = void> struct coroutine_handle {
coroutine_handle() = default;
- static coroutine_handle from_address(void *) { return {}; }
+ static coroutine_handle from_address(void *) noexcept;
};
template <> struct coroutine_handle<void> {
- static coroutine_handle from_address(void *) { return {}; }
+ static coroutine_handle from_address(void *) noexcept;
coroutine_handle() = default;
template <class PromiseType>
- coroutine_handle(coroutine_handle<PromiseType>) {}
+ coroutine_handle(coroutine_handle<PromiseType>) noexcept;
};
}
struct suspend_always {
- bool await_ready();
- void await_suspend(std::experimental::coroutine_handle<>);
- void await_resume();
+ bool await_ready() noexcept;
+ void await_suspend(std::experimental::coroutine_handle<>) noexcept;
+ void await_resume() noexcept;
};
template <> struct std::experimental::coroutine_traits<void> {
struct promise_type {
- void get_return_object();
- suspend_always initial_suspend();
- suspend_always final_suspend();
- void return_void();
+ void get_return_object() noexcept;
+ suspend_always initial_suspend() noexcept;
+ suspend_always final_suspend() noexcept;
+ void return_void() noexcept;
promise_type();
~promise_type();
- void unhandled_exception();
+ void unhandled_exception() noexcept;
};
};
struct Cleanup { ~Cleanup(); };
void may_throw();
-// CHECK: define void @_Z1fv(
+// CHECK-LABEL: define void @_Z1fv(
void f() {
// CHECK: call i8* @_Znwm(i64
@@ -52,23 +52,46 @@
// if may_throw throws, check that we destroy the promise and free the memory.
// CHECK: invoke void @_Z9may_throwv(
- // CHECK-NEXT: to label %{{.+}} unwind label %[[PromDtorPad:.+]]
+ // CHECK-NEXT: to label %{{.+}} unwind label %[[CatchPad:.+]]
// CHECK: [[DeallocPad]]:
// CHECK-NEXT: landingpad
// CHECK-NEXT: cleanup
// CHECK: br label %[[Dealloc:.+]]
- // CHECK: [[PromDtorPad]]:
- // CHECK-NEXT: landingpad
- // CHECK-NEXT: cleanup
- // CHECK: call void @_ZN7CleanupD1Ev(%struct.Cleanup*
+ // CHECK: [[CatchPad]]:
+ // CHECK-NEXT: landingpad
+ // CHECK-NEXT: catch i8* null
+ // CHECK: call void @_ZN7CleanupD1Ev(
+ // CHECK: br label %[[Catch:.+]]
+
+ // CHECK: [[Catch]]:
+ // CHECK: call i8* @__cxa_begin_catch(
+ // CHECK: call void @_ZNSt12experimental16coroutine_traitsIJvEE12promise_type19unhandled_exceptionEv(
+ // CHECK: invoke void @__cxa_end_catch()
+ // CHECK-NEXT: to label %[[Cont:.+]] unwind
+
+ // CHECK: [[Cont]]:
+ // CHECK-NEXT: br label %[[Cont2:.+]]
+ // CHECK: [[Cont2]]:
+ // CHECK-NEXT: br label %[[Cleanup:.+]]
+
+ // CHECK: [[Cleanup]]:
// CHECK: call void @_ZNSt12experimental16coroutine_traitsIJvEE12promise_typeD1Ev(
- // CHECK: br label %[[Dealloc]]
+ // CHECK: %[[Mem0:.+]] = call i8* @llvm.coro.free(
+ // CHECK: call void @_ZdlPv(i8* %[[Mem0]]
// CHECK: [[Dealloc]]:
// CHECK: %[[Mem:.+]] = call i8* @llvm.coro.free(
// CHECK: call void @_ZdlPv(i8* %[[Mem]])
co_return;
}
+
+// CHECK-LABEL: define void @_Z1gv(
+void g() {
+ for (;;)
+ co_await suspend_always{};
+ // Since this is the endless loop there should be no fallthrough handler (call to 'return_void').
+ // CHECK-NOT: call void @_ZNSt12experimental16coroutine_traitsIJvEE12promise_type11return_voidEv
+}
Index: lib/Sema/SemaCoroutine.cpp
===================================================================
--- lib/Sema/SemaCoroutine.cpp
+++ lib/Sema/SemaCoroutine.cpp
@@ -973,6 +973,15 @@
if (UnhandledException.isInvalid())
return false;
+ // Since the body of the coroutine will be wrapped in try-catch, it will
+ // be incompativle with SEH __try if present in a function.
+ if (!S.getLangOpts().Borland && Fn.FirstSEHTryLoc.isValid()) {
+ S.Diag(Fn.FirstSEHTryLoc, diag::err_seh_in_a_coroutine_with_cxx_exceptions);
+ S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
+ << Fn.getFirstCoroutineStmtKeyword();
+ return false;
+ }
+
this->OnException = UnhandledException.get();
return true;
}
Index: lib/CodeGen/CGCoroutine.cpp
===================================================================
--- lib/CodeGen/CGCoroutine.cpp
+++ lib/CodeGen/CGCoroutine.cpp
@@ -233,6 +233,15 @@
};
}
+static void emitBodyAndFallthrough(CodeGenFunction &CGF,
+ const CoroutineBodyStmt &S, Stmt *Body) {
+ CGF.EmitStmt(Body);
+ const bool CanFallthrough = CGF.Builder.GetInsertBlock();
+ if (CanFallthrough)
+ if (Stmt *OnFallthrough = S.getFallthroughHandler())
+ CGF.EmitStmt(OnFallthrough);
+}
+
void CodeGenFunction::EmitCoroutineBody(const CoroutineBodyStmt &S) {
auto *NullPtr = llvm::ConstantPointerNull::get(Builder.getInt8PtrTy());
auto &TI = CGM.getContext().getTargetInfo();
@@ -278,8 +287,20 @@
// FIXME: Emit initial suspend and more before the body.
CurCoro.Data->CurrentAwaitKind = AwaitKind::Normal;
- EmitStmt(S.getBody());
+ if (auto *OnException = S.getExceptionHandler()) {
+ auto Loc = S.getLocStart();
+ CXXCatchStmt Catch(Loc, /*exDecl=*/nullptr, OnException);
+ CXXTryStmt::OnStack TryStmt(Loc, S.getBody(), &Catch);
+
+ EnterCXXTryStmt(TryStmt);
+ emitBodyAndFallthrough(*this, S, TryStmt.getTryBlock());
+ ExitCXXTryStmt(TryStmt);
+ }
+ else {
+ emitBodyAndFallthrough(*this, S, S.getBody());
+ }
+
// See if we need to generate final suspend.
const bool CanFallthrough = Builder.GetInsertBlock();
const bool HasCoreturns = CurCoro.Data->CoreturnCount > 0;
Index: lib/AST/StmtCXX.cpp
===================================================================
--- lib/AST/StmtCXX.cpp
+++ lib/AST/StmtCXX.cpp
@@ -44,6 +44,7 @@
CXXTryStmt::CXXTryStmt(SourceLocation tryLoc, Stmt *tryBlock,
ArrayRef<Stmt *> handlers)
: Stmt(CXXTryStmtClass), TryLoc(tryLoc), NumHandlers(handlers.size()) {
+ // Must be kept in sync with CXXTryStmt::OnStack.
Stmt **Stmts = reinterpret_cast<Stmt **>(this + 1);
Stmts[0] = tryBlock;
std::copy(handlers.begin(), handlers.end(), Stmts + 1);
Index: include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- include/clang/Basic/DiagnosticSemaKinds.td
+++ include/clang/Basic/DiagnosticSemaKinds.td
@@ -8882,6 +8882,8 @@
InGroup<Coroutine>;
def err_coroutine_promise_get_return_object_on_allocation_failure : Error<
"%0: 'get_return_object_on_allocation_failure()' must be a static member function">;
+def err_seh_in_a_coroutine_with_cxx_exceptions : Error<
+ "cannot use SEH '__try' in a coroutine when C++ exceptions are enabled">;
}
let CategoryName = "Documentation Issue" in {
Index: include/clang/AST/StmtCXX.h
===================================================================
--- include/clang/AST/StmtCXX.h
+++ include/clang/AST/StmtCXX.h
@@ -117,6 +117,17 @@
}
friend class ASTStmtReader;
+ struct OnStack;
+};
+
+/// CXXTryStmt::OnStack - is an AST node for a simple CXXTryStmt
+/// with a single catch handler. It is used to construct an
+/// AST node as a local variable and should never be inserted into an AST tree.
+// Note: It must be kept in sync with CXXTryStmt constructor.
+struct CXXTryStmt::OnStack : CXXTryStmt {
+ alignas(CXXTryStmt) Stmt *Stmts[2];
+ OnStack(SourceLocation tryLoc, Stmt *tryBlock, Stmt *handler)
+ : CXXTryStmt(tryLoc, tryBlock, {handler}) {}
};
/// CXXForRangeStmt - This represents C++0x [stmt.ranged]'s ranged for
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