[clang] [Clang] Fix ICE when `initial_suspend()`'s `await_resume()` returns a non-trivially destructible type (PR #72935)
Yuxuan Chen via cfe-commits
cfe-commits at lists.llvm.org
Mon Nov 20 17:19:18 PST 2023
https://github.com/yuxuanchen1997 updated https://github.com/llvm/llvm-project/pull/72935
>From 354b4390725f9142838e2c8d3d09b058f9519c10 Mon Sep 17 00:00:00 2001
From: Yuxuan Chen <ych at meta.com>
Date: Mon, 20 Nov 2023 17:01:05 -0800
Subject: [PATCH] remove try stmt around initial suspend, merge with main try
---
clang/lib/CodeGen/CGCoroutine.cpp | 62 ++++---------------------------
1 file changed, 8 insertions(+), 54 deletions(-)
diff --git a/clang/lib/CodeGen/CGCoroutine.cpp b/clang/lib/CodeGen/CGCoroutine.cpp
index 7e449d5af3423cf..1317e075f69fa6b 100644
--- a/clang/lib/CodeGen/CGCoroutine.cpp
+++ b/clang/lib/CodeGen/CGCoroutine.cpp
@@ -129,16 +129,6 @@ static SmallString<32> buildSuspendPrefixStr(CGCoroData &Coro, AwaitKind Kind) {
return Prefix;
}
-static bool memberCallExpressionCanThrow(const Expr *E) {
- if (const auto *CE = dyn_cast<CXXMemberCallExpr>(E))
- if (const auto *Proto =
- CE->getMethodDecl()->getType()->getAs<FunctionProtoType>())
- if (isNoexceptExceptionSpec(Proto->getExceptionSpecType()) &&
- Proto->canThrow() == CT_Cannot)
- return false;
- return true;
-}
-
// Emit suspend expression which roughly looks like:
//
// auto && x = CommonExpr();
@@ -229,23 +219,8 @@ static LValueOrRValue emitSuspendExpression(CodeGenFunction &CGF, CGCoroData &Co
// Emit await_resume expression.
CGF.EmitBlock(ReadyBlock);
- // Exception handling requires additional IR. If the 'await_resume' function
- // is marked as 'noexcept', we avoid generating this additional IR.
- CXXTryStmt *TryStmt = nullptr;
- if (Coro.ExceptionHandler && Kind == AwaitKind::Init &&
- memberCallExpressionCanThrow(S.getResumeExpr())) {
- Coro.ResumeEHVar =
- CGF.CreateTempAlloca(Builder.getInt1Ty(), Prefix + Twine("resume.eh"));
- Builder.CreateFlagStore(true, Coro.ResumeEHVar);
-
- auto Loc = S.getResumeExpr()->getExprLoc();
- auto *Catch = new (CGF.getContext())
- CXXCatchStmt(Loc, /*exDecl=*/nullptr, Coro.ExceptionHandler);
- auto *TryBody = CompoundStmt::Create(CGF.getContext(), S.getResumeExpr(),
- FPOptionsOverride(), Loc, Loc);
- TryStmt = CXXTryStmt::Create(CGF.getContext(), Loc, TryBody, Catch);
- CGF.EnterCXXTryStmt(*TryStmt);
- }
+ // Never create an LValue for an initial suspend.
+ assert(Kind != AwaitKind::Init || !forLValue);
LValueOrRValue Res;
if (forLValue)
@@ -253,11 +228,6 @@ static LValueOrRValue emitSuspendExpression(CodeGenFunction &CGF, CGCoroData &Co
else
Res.RV = CGF.EmitAnyExpr(S.getResumeExpr(), aggSlot, ignoreResult);
- if (TryStmt) {
- Builder.CreateFlagStore(false, Coro.ResumeEHVar);
- CGF.ExitCXXTryStmt(*TryStmt);
- }
-
return Res;
}
@@ -711,38 +681,22 @@ void CodeGenFunction::EmitCoroutineBody(const CoroutineBodyStmt &S) {
EmitStmt(S.getInitSuspendStmt());
CurCoro.Data->FinalJD = getJumpDestInCurrentScope(FinalBB);
- CurCoro.Data->CurrentAwaitKind = AwaitKind::Normal;
-
if (CurCoro.Data->ExceptionHandler) {
- // If we generated IR to record whether an exception was thrown from
- // 'await_resume', then use that IR to determine whether the coroutine
- // body should be skipped.
- // If we didn't generate the IR (perhaps because 'await_resume' was marked
- // as 'noexcept'), then we skip this check.
- BasicBlock *ContBB = nullptr;
- if (CurCoro.Data->ResumeEHVar) {
- BasicBlock *BodyBB = createBasicBlock("coro.resumed.body");
- ContBB = createBasicBlock("coro.resumed.cont");
- Value *SkipBody = Builder.CreateFlagLoad(CurCoro.Data->ResumeEHVar,
- "coro.resumed.eh");
- Builder.CreateCondBr(SkipBody, ContBB, BodyBB);
- EmitBlock(BodyBB);
- }
-
auto Loc = S.getBeginLoc();
CXXCatchStmt Catch(Loc, /*exDecl=*/nullptr,
CurCoro.Data->ExceptionHandler);
+
auto *TryStmt =
CXXTryStmt::Create(getContext(), Loc, S.getBody(), &Catch);
EnterCXXTryStmt(*TryStmt);
+ EmitStmt(S.getInitSuspendStmt());
+ CurCoro.Data->CurrentAwaitKind = AwaitKind::Normal;
emitBodyAndFallthrough(*this, S, TryStmt->getTryBlock());
ExitCXXTryStmt(*TryStmt);
-
- if (ContBB)
- EmitBlock(ContBB);
- }
- else {
+ } else {
+ EmitStmt(S.getInitSuspendStmt());
+ CurCoro.Data->CurrentAwaitKind = AwaitKind::Normal;
emitBodyAndFallthrough(*this, S, S.getBody());
}
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