Index: lib/CodeGen/CGCoroutine.cpp =================================================================== --- lib/CodeGen/CGCoroutine.cpp +++ lib/CodeGen/CGCoroutine.cpp @@ -11,6 +11,7 @@ // //===----------------------------------------------------------------------===// +#include "CGCleanup.h" #include "CodeGenFunction.h" #include "llvm/ADT/ScopeExit.h" #include "clang/AST/StmtCXX.h" @@ -326,6 +327,72 @@ }; } +namespace { +struct GetReturnObjectManager { + CodeGenFunction &CGF; + CGBuilderTy &Builder; + const CoroutineBodyStmt &S; + + Address GroActiveFlag; + CodeGenFunction::AutoVarEmission GroEmission; + + GetReturnObjectManager(CodeGenFunction &CGF, const CoroutineBodyStmt &S) + : CGF(CGF), Builder(CGF.Builder), S(S), GroActiveFlag(Address::invalid()), + GroEmission(CodeGenFunction::AutoVarEmission::invalid()) {} + + // The gro variable has to outlive coroutine frame and coroutine promise, but, + // it can only be initialized after coroutine promise was created, thus, we + // split its emission in two parts. EmitGroAlloca emits an alloca and sets up + // cleanups. Later when coroutine promise is available we initialize the gro + // and sets the flag that the cleanup is now active. + + void EmitGroAlloca() { + auto *GroDeclStmt = dyn_cast(S.getResultDecl()); + if (!GroDeclStmt) { + // If get_return_object returns void, no need to do an alloca. + return; + } + + auto *GroVarDecl = cast(GroDeclStmt->getSingleDecl()); + + // Set GRO flag that it is not initialized yet + GroActiveFlag = + CGF.CreateTempAlloca(Builder.getInt1Ty(), CharUnits::One(), "gro.active"); + Builder.CreateStore(Builder.getFalse(), GroActiveFlag); + + GroEmission = CGF.EmitAutoVarAlloca(*GroVarDecl); + + // Remember the top of EHStack before emitting the cleanup. + auto old_top = CGF.EHStack.stable_begin(); + CGF.EmitAutoVarCleanups(GroEmission); + auto top = CGF.EHStack.stable_begin(); + + // Make the cleanup conditional on gro.active + for (auto b = CGF.EHStack.find(top), e = CGF.EHStack.find(old_top); + b != e; b++) { + if (auto *Cleanup = dyn_cast(&*b)) { + assert(!Cleanup->hasActiveFlag() && "cleanup already has active flag?"); + Cleanup->setActiveFlag(GroActiveFlag); + Cleanup->setTestFlagInEHCleanup(); + Cleanup->setTestFlagInNormalCleanup(); + } + } + } + + void EmitGroInit() { + if (!GroActiveFlag.isValid()) { + // No Gro variable was allocated. Simply emit the call to + // get_return_object. + CGF.EmitStmt(S.getResultDecl()); + return; + } + + CGF.EmitAutoVarInit(GroEmission); + Builder.CreateStore(Builder.getTrue(), GroActiveFlag); + } +}; +} + static void emitBodyAndFallthrough(CodeGenFunction &CGF, const CoroutineBodyStmt &S, Stmt *Body) { CGF.EmitStmt(Body); @@ -390,14 +457,18 @@ CGM.getIntrinsic(llvm::Intrinsic::coro_begin), {CoroId, Phi}); CurCoro.Data->CoroBegin = CoroBegin; + GetReturnObjectManager GroManager(*this, S); + GroManager.EmitGroAlloca(); + CurCoro.Data->CleanupJD = getJumpDestInCurrentScope(RetBB); { CodeGenFunction::RunCleanupsScope ResumeScope(*this); EHStack.pushCleanup(NormalAndEHCleanup, S.getDeallocate()); EmitStmt(S.getPromiseDeclStmt()); - EmitStmt(S.getResultDecl()); // FIXME: Gro lifetime is wrong. + // Now we have the promise, initialize the GRO + GroManager.EmitGroInit(); EHStack.pushCleanup(EHCleanup); CurCoro.Data->FinalJD = getJumpDestInCurrentScope(FinalBB); Index: test/CodeGenCoroutines/coro-gro.cpp =================================================================== --- /dev/null +++ test/CodeGenCoroutines/coro-gro.cpp @@ -0,0 +1,86 @@ +// Verifies lifetime of __gro local variable +// Verify that coroutine promise and allocated memory are freed up on exception. +// RUN: %clang_cc1 -std=c++1z -fcoroutines-ts -triple=x86_64-unknown-linux-gnu -emit-llvm -o - %s -disable-llvm-passes | FileCheck %s + +namespace std::experimental { +template struct coroutine_traits; + +template struct coroutine_handle { + coroutine_handle() = default; + static coroutine_handle from_address(void *) noexcept; +}; +template <> struct coroutine_handle { + static coroutine_handle from_address(void *) noexcept; + coroutine_handle() = default; + template + coroutine_handle(coroutine_handle) noexcept; +}; +} + +struct suspend_always { + bool await_ready() noexcept; + void await_suspend(std::experimental::coroutine_handle<>) noexcept; + void await_resume() noexcept; +}; + +struct GroType { + ~GroType(); + operator int() noexcept; +}; + +template <> struct std::experimental::coroutine_traits { + struct promise_type { + GroType 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() noexcept; + }; +}; + +struct Cleanup { ~Cleanup(); }; +void doSomething() noexcept; + +// CHECK: define i32 @_Z1fv( +int f() { + // CHECK: %[[RetVal:.+]] = alloca i32 + // CHECK: %[[GroActive:.+]] = alloca i1 + + // CHECK: %[[Size:.+]] = call i64 @llvm.coro.size.i64() + // CHECK: call i8* @_Znwm(i64 %[[Size]]) + // CHECK: store i1 false, i1* %[[GroActive]] + // CHECK: call void @_ZNSt12experimental16coroutine_traitsIJiEE12promise_typeC1Ev( + // CHECK: call void @_ZNSt12experimental16coroutine_traitsIJiEE12promise_type17get_return_objectEv( + // CHECK: store i1 true, i1* %[[GroActive]] + + Cleanup cleanup; + doSomething(); + co_return; + + // CHECK: call void @_Z11doSomethingv( + // CHECK: call void @_ZNSt12experimental16coroutine_traitsIJiEE12promise_type11return_voidEv( + // CHECK: call void @_ZN7CleanupD1Ev( + + // Destroy promise and free the memory. + + // CHECK: call void @_ZNSt12experimental16coroutine_traitsIJiEE12promise_typeD1Ev( + // CHECK: %[[Mem:.+]] = call i8* @llvm.coro.free( + // CHECK: call void @_ZdlPv(i8* %[[Mem]]) + + // Initialize retval from Gro and destroy Gro + + // CHECK: %[[Conv:.+]] = call i32 @_ZN7GroTypecviEv( + // CHECK: store i32 %[[Conv]], i32* %[[RetVal]] + // CHECK: %[[IsActive:.+]] = load i1, i1* %[[GroActive]] + // CHECK: br i1 %[[IsActive]], label %[[CleanupGro:.+]], label %[[Done:.+]] + + // CHECK: [[CleanupGro]]: + // CHECK: call void @_ZN7GroTypeD1Ev( + // CHECK: br label %[[Done]] + + // CHECK: [[Done]]: + // CHECK: %[[LoadRet:.+]] = load i32, i32* %[[RetVal]] + // CHECK: ret i32 %[[LoadRet]] +}