[clang] [llvm] Implement llvm.coro.await.suspend intrinsic (PR #79712)
via cfe-commits
cfe-commits at lists.llvm.org
Sat Jan 27 14:48:37 PST 2024
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-coroutines
@llvm/pr-subscribers-clang
Author: None (fpasserby)
<details>
<summary>Changes</summary>
Implement `llvm.coro.await.suspend` intrinsics, to deal with performance regression after prohibiting `.await_suspend` inlining, as suggested in #<!-- -->64945.
Actually, there are three new intrinsics, which directly correspond to each of three forms of `await_suspend`:
```
void llvm.coro.await.suspend(ptr %awaiter, ptr %frame, ptr @<!-- -->helperFunction)
i1 llvm.coro.await.suspend.bool(ptr %awaiter, ptr %frame, ptr @<!-- -->helperFunction)
ptr llvm.coro.await.suspend.handle(ptr %awaiter, ptr %frame, ptr @<!-- -->helperFunction)
```
There are three different versions instead of one, because in `bool` case it's result is used for resuming via a branch, and in `coroutine_handle` case exceptions from `await_suspend` are handled in the coroutine, and exceptions from the subsequent `.resume()` are propagated to the caller.
Await-suspend block is simplified down to intrinsic calls only, for example for the symmetric transfer case:
```
%id = call token @<!-- -->llvm.coro.save(ptr null)
%handle = call ptr @<!-- -->llvm.coro.await.suspend.handle(ptr %awaiter, ptr %frame, ptr @<!-- -->helperFunction)
call void @<!-- -->llvm.coro.resume(%handle)
%result = call i8 @<!-- -->llvm.coro.suspend(token %id, i1 false)
switch i8 %result, ...
```
All the await-suspend logic is moved out into a helper function, generated for each suspension point.
The signature of the function is `<type> helperFunction(ptr %awaiter, ptr %frame)` where `<type>` is one of `void` `i1` or `ptr`, depending on the return type of `await_suspend`.
The intrinsic calls are lowered and helper functions bodies are inlined during `CoroSplit` pass, right after the split.
Because I'm new to LLVM, I'm not sure if the helper function generation, calls to them and lowering are implemented in the right way, especially with regard to various metadata and attributes, i. e. for TBAA. All things, that seemed questionable, are marked with `FIXME` comments.
There is another detail: in case of symmetric transfer raw pointer to the frame of coroutine, that should be resumed, is returned from the helper function and a direct call to `@<!-- -->llvm.coro.resume` is generated. C++ standard demands, that `.resume()` method is evaluated. Not sure how important is this, because code has been generated in the same way before, sans helper function.
---
Patch is 58.82 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/79712.diff
20 Files Affected:
- (modified) clang/include/clang/AST/ExprCXX.h (+20-8)
- (modified) clang/lib/CodeGen/CGCoroutine.cpp (+132-11)
- (modified) clang/lib/CodeGen/CodeGenFunction.h (+4)
- (modified) clang/lib/Sema/SemaCoroutine.cpp (+84-76)
- (modified) clang/test/AST/coroutine-locals-cleanup.cpp (+2-8)
- (modified) clang/test/CodeGenCoroutines/coro-always-inline.cpp (+1-1)
- (modified) clang/test/CodeGenCoroutines/coro-await.cpp (+62-17)
- (removed) clang/test/CodeGenCoroutines/coro-awaiter-noinline-suspend.cpp (-168)
- (modified) clang/test/CodeGenCoroutines/coro-dwarf.cpp (+12)
- (modified) clang/test/CodeGenCoroutines/coro-function-try-block.cpp (+1-1)
- (added) clang/test/CodeGenCoroutines/coro-simplify-suspend-point.cpp (+67)
- (modified) clang/test/CodeGenCoroutines/coro-symmetric-transfer-01.cpp (+2-6)
- (modified) clang/test/CodeGenCoroutines/coro-symmetric-transfer-02.cpp (+4-8)
- (modified) clang/test/CodeGenCoroutines/pr59181.cpp (+5-4)
- (modified) clang/test/SemaCXX/co_await-ast.cpp (+4-3)
- (modified) llvm/include/llvm/IR/Intrinsics.td (+12)
- (modified) llvm/lib/IR/Verifier.cpp (+3)
- (modified) llvm/lib/Transforms/Coroutines/CoroInstr.h (+30)
- (modified) llvm/lib/Transforms/Coroutines/CoroSplit.cpp (+142-25)
- (modified) llvm/lib/Transforms/Coroutines/Coroutines.cpp (+3)
``````````diff
diff --git a/clang/include/clang/AST/ExprCXX.h b/clang/include/clang/AST/ExprCXX.h
index a0e467b35778c5c..57a505036def409 100644
--- a/clang/include/clang/AST/ExprCXX.h
+++ b/clang/include/clang/AST/ExprCXX.h
@@ -5035,15 +5035,19 @@ class CoroutineSuspendExpr : public Expr {
enum SubExpr { Operand, Common, Ready, Suspend, Resume, Count };
Stmt *SubExprs[SubExpr::Count];
+ bool IsSuspendNoThrow = false;
OpaqueValueExpr *OpaqueValue = nullptr;
+ OpaqueValueExpr *OpaqueFramePtr = nullptr;
public:
CoroutineSuspendExpr(StmtClass SC, SourceLocation KeywordLoc, Expr *Operand,
Expr *Common, Expr *Ready, Expr *Suspend, Expr *Resume,
- OpaqueValueExpr *OpaqueValue)
+ bool IsSuspendNoThrow, OpaqueValueExpr *OpaqueValue,
+ OpaqueValueExpr *OpaqueFramePtr)
: Expr(SC, Resume->getType(), Resume->getValueKind(),
Resume->getObjectKind()),
- KeywordLoc(KeywordLoc), OpaqueValue(OpaqueValue) {
+ KeywordLoc(KeywordLoc), IsSuspendNoThrow(IsSuspendNoThrow),
+ OpaqueValue(OpaqueValue), OpaqueFramePtr(OpaqueFramePtr) {
SubExprs[SubExpr::Operand] = Operand;
SubExprs[SubExpr::Common] = Common;
SubExprs[SubExpr::Ready] = Ready;
@@ -5080,6 +5084,9 @@ class CoroutineSuspendExpr : public Expr {
/// getOpaqueValue - Return the opaque value placeholder.
OpaqueValueExpr *getOpaqueValue() const { return OpaqueValue; }
+ /// getOpaqueFramePtr - Return coroutine frame pointer placeholder.
+ OpaqueValueExpr *getOpaqueFramePtr() const { return OpaqueFramePtr; }
+
Expr *getReadyExpr() const {
return static_cast<Expr*>(SubExprs[SubExpr::Ready]);
}
@@ -5097,6 +5104,8 @@ class CoroutineSuspendExpr : public Expr {
return static_cast<Expr *>(SubExprs[SubExpr::Operand]);
}
+ bool isSuspendNoThrow() const { return IsSuspendNoThrow; }
+
SourceLocation getKeywordLoc() const { return KeywordLoc; }
SourceLocation getBeginLoc() const LLVM_READONLY { return KeywordLoc; }
@@ -5125,10 +5134,12 @@ class CoawaitExpr : public CoroutineSuspendExpr {
public:
CoawaitExpr(SourceLocation CoawaitLoc, Expr *Operand, Expr *Common,
- Expr *Ready, Expr *Suspend, Expr *Resume,
- OpaqueValueExpr *OpaqueValue, bool IsImplicit = false)
+ Expr *Ready, Expr *Suspend, Expr *Resume, bool IsSuspendNoThrow,
+ OpaqueValueExpr *OpaqueValue, OpaqueValueExpr *OpaqueFramePtr,
+ bool IsImplicit = false)
: CoroutineSuspendExpr(CoawaitExprClass, CoawaitLoc, Operand, Common,
- Ready, Suspend, Resume, OpaqueValue) {
+ Ready, Suspend, Resume, IsSuspendNoThrow,
+ OpaqueValue, OpaqueFramePtr) {
CoawaitBits.IsImplicit = IsImplicit;
}
@@ -5206,10 +5217,11 @@ class CoyieldExpr : public CoroutineSuspendExpr {
public:
CoyieldExpr(SourceLocation CoyieldLoc, Expr *Operand, Expr *Common,
- Expr *Ready, Expr *Suspend, Expr *Resume,
- OpaqueValueExpr *OpaqueValue)
+ Expr *Ready, Expr *Suspend, Expr *Resume, bool IsSuspendNoThrow,
+ OpaqueValueExpr *OpaqueValue, OpaqueValueExpr *OpaqueFramePtr)
: CoroutineSuspendExpr(CoyieldExprClass, CoyieldLoc, Operand, Common,
- Ready, Suspend, Resume, OpaqueValue) {}
+ Ready, Suspend, Resume, IsSuspendNoThrow,
+ OpaqueValue, OpaqueFramePtr) {}
CoyieldExpr(SourceLocation CoyieldLoc, QualType Ty, Expr *Operand,
Expr *Common)
: CoroutineSuspendExpr(CoyieldExprClass, CoyieldLoc, Ty, Operand,
diff --git a/clang/lib/CodeGen/CGCoroutine.cpp b/clang/lib/CodeGen/CGCoroutine.cpp
index 888d30bfb3e1d6a..1c768df41d43c09 100644
--- a/clang/lib/CodeGen/CGCoroutine.cpp
+++ b/clang/lib/CodeGen/CGCoroutine.cpp
@@ -212,9 +212,10 @@ static LValueOrRValue emitSuspendExpression(CodeGenFunction &CGF, CGCoroData &Co
bool ignoreResult, bool forLValue) {
auto *E = S.getCommonExpr();
- auto Binder =
+ auto CommonBinder =
CodeGenFunction::OpaqueValueMappingData::bind(CGF, S.getOpaqueValue(), E);
- auto UnbindOnExit = llvm::make_scope_exit([&] { Binder.unbind(CGF); });
+ auto UnbindCommonOnExit =
+ llvm::make_scope_exit([&] { CommonBinder.unbind(CGF); });
auto Prefix = buildSuspendPrefixStr(Coro, Kind);
BasicBlock *ReadyBlock = CGF.createBasicBlock(Prefix + Twine(".ready"));
@@ -232,16 +233,57 @@ static LValueOrRValue emitSuspendExpression(CodeGenFunction &CGF, CGCoroData &Co
auto *NullPtr = llvm::ConstantPointerNull::get(CGF.CGM.Int8PtrTy);
auto *SaveCall = Builder.CreateCall(CoroSave, {NullPtr});
- CGF.CurCoro.InSuspendBlock = true;
- auto *SuspendRet = CGF.EmitScalarExpr(S.getSuspendExpr());
- CGF.CurCoro.InSuspendBlock = false;
+ auto SuspendHelper = CodeGenFunction(CGF.CGM).generateAwaitSuspendHelper(
+ CGF.CurFn->getName(), Prefix, S);
- if (SuspendRet != nullptr && SuspendRet->getType()->isIntegerTy(1)) {
- // Veto suspension if requested by bool returning await_suspend.
- BasicBlock *RealSuspendBlock =
- CGF.createBasicBlock(Prefix + Twine(".suspend.bool"));
- CGF.Builder.CreateCondBr(SuspendRet, RealSuspendBlock, ReadyBlock);
- CGF.EmitBlock(RealSuspendBlock);
+ llvm::CallBase *SuspendRet = nullptr;
+
+ {
+ CGF.CurCoro.InSuspendBlock = true;
+
+ auto FramePtrBinder = CodeGenFunction::OpaqueValueMappingData::bind(
+ CGF, S.getOpaqueFramePtr(), S.getOpaqueFramePtr()->getSourceExpr());
+ auto UnbindFramePtrOnExit =
+ llvm::make_scope_exit([&] { FramePtrBinder.unbind(CGF); });
+
+ SmallVector<llvm::Value *, 3> SuspendHelperCallArgs;
+ SuspendHelperCallArgs.push_back(
+ CGF.getOrCreateOpaqueLValueMapping(S.getOpaqueValue()).getPointer(CGF));
+ SuspendHelperCallArgs.push_back(
+ CGF.getOrCreateOpaqueRValueMapping(S.getOpaqueFramePtr())
+ .getScalarVal());
+ SuspendHelperCallArgs.push_back(SuspendHelper);
+
+ auto IID = llvm::Intrinsic::coro_await_suspend;
+ if (S.getSuspendExpr()->getType()->isBooleanType())
+ IID = llvm::Intrinsic::coro_await_suspend_bool;
+ else if (S.getSuspendExpr()->getType()->isVoidPointerType())
+ IID = llvm::Intrinsic::coro_await_suspend_handle;
+
+ llvm::Function *AwaitSuspendIntrinsic = CGF.CGM.getIntrinsic(IID);
+ // FIXME: add call attributes?
+ if (S.isSuspendNoThrow()) {
+ SuspendRet = CGF.EmitNounwindRuntimeCall(AwaitSuspendIntrinsic,
+ SuspendHelperCallArgs);
+ } else {
+ SuspendRet =
+ CGF.EmitCallOrInvoke(AwaitSuspendIntrinsic, SuspendHelperCallArgs);
+ }
+
+ CGF.CurCoro.InSuspendBlock = false;
+ }
+
+ if (SuspendRet != nullptr) {
+ if (SuspendRet->getType()->isIntegerTy(1)) {
+ // Veto suspension if requested by bool returning await_suspend.
+ BasicBlock *RealSuspendBlock =
+ CGF.createBasicBlock(Prefix + Twine(".suspend.bool"));
+ CGF.Builder.CreateCondBr(SuspendRet, RealSuspendBlock, ReadyBlock);
+ CGF.EmitBlock(RealSuspendBlock);
+ } else if (SuspendRet->getType()->isPointerTy()) {
+ auto ResumeIntrinsic = CGF.CGM.getIntrinsic(llvm::Intrinsic::coro_resume);
+ Builder.CreateCall(ResumeIntrinsic, SuspendRet);
+ }
}
// Emit the suspend point.
@@ -338,6 +380,85 @@ static QualType getCoroutineSuspendExprReturnType(const ASTContext &Ctx,
}
#endif
+llvm::Function *
+CodeGenFunction::generateAwaitSuspendHelper(Twine const &CoroName,
+ Twine const &SuspendPointName,
+ CoroutineSuspendExpr const &S) {
+ std::string FuncName = "__await_suspend_helper_";
+ FuncName += CoroName.str();
+ FuncName += SuspendPointName.str();
+
+ ASTContext &C = getContext();
+
+ FunctionArgList args;
+
+ ImplicitParamDecl AwaiterDecl(C, C.VoidPtrTy, ImplicitParamKind::Other);
+ ImplicitParamDecl FrameDecl(C, C.VoidPtrTy, ImplicitParamKind::Other);
+ QualType ReturnTy = S.getSuspendExpr()->getType();
+
+ if (ReturnTy->isBooleanType()) {
+ ReturnTy = C.BoolTy;
+ } else if (ReturnTy->isVoidPointerType()) {
+ ReturnTy = C.VoidPtrTy;
+ } else {
+ ReturnTy = C.VoidTy;
+ }
+
+ args.push_back(&AwaiterDecl);
+ args.push_back(&FrameDecl);
+
+ const CGFunctionInfo &FI =
+ CGM.getTypes().arrangeBuiltinFunctionDeclaration(ReturnTy, args);
+
+ llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
+
+ llvm::Function *Fn = llvm::Function::Create(
+ LTy, llvm::GlobalValue::PrivateLinkage, FuncName, &CGM.getModule());
+
+ Fn->addParamAttr(0, llvm::Attribute::AttrKind::NonNull);
+ Fn->addParamAttr(0, llvm::Attribute::AttrKind::NoUndef);
+
+ Fn->addParamAttr(1, llvm::Attribute::AttrKind::NoUndef);
+
+ Fn->setMustProgress();
+ Fn->addFnAttr(llvm::Attribute::AttrKind::AlwaysInline);
+
+ if (S.isSuspendNoThrow()) {
+ Fn->addFnAttr(llvm::Attribute::AttrKind::NoUnwind);
+ }
+
+ StartFunction(GlobalDecl(), ReturnTy, Fn, FI, args);
+
+ llvm::Value *AwaiterPtr = Builder.CreateLoad(GetAddrOfLocalVar(&AwaiterDecl));
+ auto AwaiterLValue =
+ MakeNaturalAlignAddrLValue(AwaiterPtr, AwaiterDecl.getType());
+
+ // FIXME: mark as aliasing with awaiter?
+ // FIXME: TBAA?
+ // FIXME: emit in a better way (maybe egenerate AST in SemaCoroutine)?
+ auto FramePtrRValue =
+ RValue::get(Builder.CreateLoad(GetAddrOfLocalVar(&FrameDecl)));
+
+ auto AwaiterBinder = CodeGenFunction::OpaqueValueMappingData::bind(
+ *this, S.getOpaqueValue(), AwaiterLValue);
+ auto FramePtrBinder = CodeGenFunction::OpaqueValueMappingData::bind(
+ *this, S.getOpaqueFramePtr(), FramePtrRValue);
+
+ auto *SuspendRet = EmitScalarExpr(S.getSuspendExpr());
+
+ auto UnbindCommonOnExit =
+ llvm::make_scope_exit([&] { AwaiterBinder.unbind(*this); });
+ auto UnbindFramePtrOnExit =
+ llvm::make_scope_exit([&] { FramePtrBinder.unbind(*this); });
+ if (SuspendRet != nullptr) {
+ Fn->addRetAttr(llvm::Attribute::AttrKind::NoUndef);
+ Builder.CreateStore(SuspendRet, ReturnValue);
+ }
+
+ FinishFunction();
+ return Fn;
+}
+
LValue
CodeGenFunction::EmitCoawaitLValue(const CoawaitExpr *E) {
assert(getCoroutineSuspendExprReturnType(getContext(), E)->isReferenceType() &&
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index 143ad64e8816b12..811dbd9aed44e46 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -350,6 +350,10 @@ class CodeGenFunction : public CodeGenTypeCache {
return isCoroutine() && CurCoro.InSuspendBlock;
}
+ llvm::Function *generateAwaitSuspendHelper(Twine const &CoroName,
+ Twine const &SuspendPointName,
+ CoroutineSuspendExpr const &S);
+
/// CurGD - The GlobalDecl for the current function being compiled.
GlobalDecl CurGD;
diff --git a/clang/lib/Sema/SemaCoroutine.cpp b/clang/lib/Sema/SemaCoroutine.cpp
index a969b9383563b22..a46744205d0f298 100644
--- a/clang/lib/Sema/SemaCoroutine.cpp
+++ b/clang/lib/Sema/SemaCoroutine.cpp
@@ -31,6 +31,8 @@
using namespace clang;
using namespace sema;
+static bool isNoThrow(Sema &S, const Stmt *E);
+
static LookupResult lookupMember(Sema &S, const char *Name, CXXRecordDecl *RD,
SourceLocation Loc, bool &Res) {
DeclarationName DN = S.PP.getIdentifierInfo(Name);
@@ -266,7 +268,7 @@ static ExprResult buildOperatorCoawaitCall(Sema &SemaRef, Scope *S,
}
static ExprResult buildCoroutineHandle(Sema &S, QualType PromiseType,
- SourceLocation Loc) {
+ Expr *FramePtr, SourceLocation Loc) {
QualType CoroHandleType = lookupCoroutineHandleType(S, PromiseType, Loc);
if (CoroHandleType.isNull())
return ExprError();
@@ -280,9 +282,6 @@ static ExprResult buildCoroutineHandle(Sema &S, QualType PromiseType,
return ExprError();
}
- Expr *FramePtr =
- S.BuildBuiltinCallExpr(Loc, Builtin::BI__builtin_coro_frame, {});
-
CXXScopeSpec SS;
ExprResult FromAddr =
S.BuildDeclarationNameExpr(SS, Found, /*NeedsADL=*/false);
@@ -296,6 +295,8 @@ struct ReadySuspendResumeResult {
enum AwaitCallType { ACT_Ready, ACT_Suspend, ACT_Resume };
Expr *Results[3];
OpaqueValueExpr *OpaqueValue;
+ OpaqueValueExpr *OpaqueFramePtr;
+ bool IsSuspendNoThrow;
bool IsInvalid;
};
@@ -380,66 +381,7 @@ static Expr *maybeTailCall(Sema &S, QualType RetType, Expr *E,
// __builtin_coro_resume so that the cleanup code are not inserted in-between
// the resume call and return instruction, which would interfere with the
// musttail call contract.
- JustAddress = S.MaybeCreateExprWithCleanups(JustAddress);
- return S.BuildBuiltinCallExpr(Loc, Builtin::BI__builtin_coro_resume,
- JustAddress);
-}
-
-/// The await_suspend call performed by co_await is essentially asynchronous
-/// to the execution of the coroutine. Inlining it normally into an unsplit
-/// coroutine can cause miscompilation because the coroutine CFG misrepresents
-/// the true control flow of the program: things that happen in the
-/// await_suspend are not guaranteed to happen prior to the resumption of the
-/// coroutine, and things that happen after the resumption of the coroutine
-/// (including its exit and the potential deallocation of the coroutine frame)
-/// are not guaranteed to happen only after the end of await_suspend.
-///
-/// See https://github.com/llvm/llvm-project/issues/56301 and
-/// https://reviews.llvm.org/D157070 for the example and the full discussion.
-///
-/// The short-term solution to this problem is to mark the call as uninlinable.
-/// But we don't want to do this if the call is known to be trivial, which is
-/// very common.
-///
-/// The long-term solution may introduce patterns like:
-///
-/// call @llvm.coro.await_suspend(ptr %awaiter, ptr %handle,
-/// ptr @awaitSuspendFn)
-///
-/// Then it is much easier to perform the safety analysis in the middle end.
-/// If it is safe to inline the call to awaitSuspend, we can replace it in the
-/// CoroEarly pass. Otherwise we could replace it in the CoroSplit pass.
-static void tryMarkAwaitSuspendNoInline(Sema &S, OpaqueValueExpr *Awaiter,
- CallExpr *AwaitSuspend) {
- // The method here to extract the awaiter decl is not precise.
- // This is intentional. Since it is hard to perform the analysis in the
- // frontend due to the complexity of C++'s type systems.
- // And we prefer to perform such analysis in the middle end since it is
- // easier to implement and more powerful.
- CXXRecordDecl *AwaiterDecl =
- Awaiter->getType().getNonReferenceType()->getAsCXXRecordDecl();
-
- if (AwaiterDecl && AwaiterDecl->field_empty())
- return;
-
- FunctionDecl *FD = AwaitSuspend->getDirectCallee();
-
- assert(FD);
-
- // If the `await_suspend()` function is marked as `always_inline` explicitly,
- // we should give the user the right to control the codegen.
- if (FD->hasAttr<NoInlineAttr>() || FD->hasAttr<AlwaysInlineAttr>())
- return;
-
- // This is problematic if the user calls the await_suspend standalone. But on
- // the on hand, it is not incorrect semantically since inlining is not part
- // of the standard. On the other hand, it is relatively rare to call
- // the await_suspend function standalone.
- //
- // And given we've already had the long-term plan, the current workaround
- // looks relatively tolerant.
- FD->addAttr(
- NoInlineAttr::CreateImplicit(S.getASTContext(), FD->getLocation()));
+ return S.MaybeCreateExprWithCleanups(JustAddress);
}
/// Build calls to await_ready, await_suspend, and await_resume for a co_await
@@ -461,7 +403,11 @@ static ReadySuspendResumeResult buildCoawaitCalls(Sema &S, VarDecl *CoroPromise,
// Assume valid until we see otherwise.
// Further operations are responsible for setting IsInalid to true.
- ReadySuspendResumeResult Calls = {{}, Operand, /*IsInvalid=*/false};
+ ReadySuspendResumeResult Calls = {{},
+ Operand,
+ /*OpaqueFramePtr=*/nullptr,
+ /*IsSuspendNoThrow=*/false,
+ /*IsInvalid=*/false};
using ACT = ReadySuspendResumeResult::AwaitCallType;
@@ -495,8 +441,17 @@ static ReadySuspendResumeResult buildCoawaitCalls(Sema &S, VarDecl *CoroPromise,
Calls.Results[ACT::ACT_Ready] = S.MaybeCreateExprWithCleanups(Conv.get());
}
+ Expr *GetFramePtr =
+ S.BuildBuiltinCallExpr(Loc, Builtin::BI__builtin_coro_frame, {});
+
+ OpaqueValueExpr *FramePtr = new (S.Context)
+ OpaqueValueExpr(Loc, GetFramePtr->getType(), VK_PRValue,
+ GetFramePtr->getObjectKind(), GetFramePtr);
+
+ Calls.OpaqueFramePtr = FramePtr;
+
ExprResult CoroHandleRes =
- buildCoroutineHandle(S, CoroPromise->getType(), Loc);
+ buildCoroutineHandle(S, CoroPromise->getType(), FramePtr, Loc);
if (CoroHandleRes.isInvalid()) {
Calls.IsInvalid = true;
return Calls;
@@ -513,10 +468,6 @@ static ReadySuspendResumeResult buildCoawaitCalls(Sema &S, VarDecl *CoroPromise,
// type Z.
QualType RetType = AwaitSuspend->getCallReturnType(S.Context);
- // We need to mark await_suspend as noinline temporarily. See the comment
- // of tryMarkAwaitSuspendNoInline for details.
- tryMarkAwaitSuspendNoInline(S, Operand, AwaitSuspend);
-
// Support for coroutine_handle returning await_suspend.
if (Expr *TailCallSuspend =
maybeTailCall(S, RetType, AwaitSuspend, Loc))
@@ -542,6 +493,10 @@ static ReadySuspendResumeResult buildCoawaitCalls(Sema &S, VarDecl *CoroPromise,
}
}
+ if (Calls.Results[ACT::ACT_Suspend]) {
+ Calls.IsSuspendNoThrow = isNoThrow(S, Calls.Results[ACT::ACT_Suspend]);
+ }
+
BuildSubExpr(ACT::ACT_Resume, "await_resume", std::nullopt);
// Make sure the awaiter object gets a chance to be cleaned up.
@@ -694,6 +649,59 @@ static FunctionScopeInfo *checkCoroutineContext(Sema &S, SourceLocation Loc,
return ScopeInfo;
}
+/// Recursively check \p E and all its children to see if any call target
+/// (including constructor call) is declared noexcept. Also any value returned
+/// from the call has a noexcept destructor.
+static bool isNoThrow(Sema &S, const Stmt *E) {
+ auto isDeclNoexcept = [&](const Decl *D, bool IsDtor = false) -> bool {
+ // In the case of dtor, the call to dtor is implicit and hence we should
+ // pass nullptr to canCalleeThrow.
+ if (Sema::canCalleeThrow(S, IsDtor ? nullptr : cast<Expr>(E), D)) {
+ return false;
+ }
+ return true;
+ };
+
+ if (auto *CE = dyn_cast<CXXConstructExpr>(E)) {
+ CXXConstructorDecl *Ctor = CE->getConstructor();
+ if (!isDeclNoexcept(Ctor)) {
+ return false;
+ }
+ // Check the corresponding destructor of the constructor.
+ if (!isDeclNoexcept(Ctor->getParent()->getDestructor(), /*IsDtor=*/true)) {
+ return false;
+ }
+ } else if (auto *CE = dyn_cast<CallExpr>(E)) {
+ if (CE->isTypeDependent())
+ return false;
+
+ if (!isDeclNoexcept(CE->getCalleeDecl())) {
+ return false;
+ }
+
+ QualType ReturnType = CE->getCallReturnType(S.getASTContext());
+ // Check the destructor of the call return type, if any.
+ if (ReturnType.isDestructedType() ==
+ QualType::DestructionKind::DK_cxx_destructor) {
+ const auto *T =
+ cast<RecordType>(ReturnType.getCanonicalType().getTypePtr());
+ if (!isDeclNoexcept(cast<CXXRecordDecl>(T->getDecl())->getDestructor(),
+ /*IsDtor=*/true)) {
+ return false;
+ }
+ }
+ }
+ for (const auto *Child : E->children()) {
+ if (!Child)
+ continue;
+ if (!isNoThrow(S, Child)) {
+ return false;
+ }
+ }
+
+ return true;
+}
+
/// Recursively check \p E and all its children to see if any call target
/// (including constructor call) is declared noexcept. Also any value returned
/// from the call has a noexcept destructor.
@@ -992,9 +1000,9 @@ ExprResult Sema::BuildR...
[truncated]
``````````
</details>
https://github.com/llvm/llvm-project/pull/79712
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