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Diffstat (limited to 'lib/CodeGen/CGCoroutine.cpp')
-rw-r--r-- | lib/CodeGen/CGCoroutine.cpp | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/lib/CodeGen/CGCoroutine.cpp b/lib/CodeGen/CGCoroutine.cpp new file mode 100644 index 000000000000..2fdb1279ece9 --- /dev/null +++ b/lib/CodeGen/CGCoroutine.cpp @@ -0,0 +1,116 @@ +//===----- CGCoroutine.cpp - Emit LLVM Code for C++ coroutines ------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This contains code dealing with C++ code generation of coroutines. +// +//===----------------------------------------------------------------------===// + +#include "CodeGenFunction.h" +#include "clang/AST/StmtCXX.h" + +using namespace clang; +using namespace CodeGen; + +namespace clang { +namespace CodeGen { + +struct CGCoroData { + // Stores the llvm.coro.id emitted in the function so that we can supply it + // as the first argument to coro.begin, coro.alloc and coro.free intrinsics. + // Note: llvm.coro.id returns a token that cannot be directly expressed in a + // builtin. + llvm::CallInst *CoroId = nullptr; + // If coro.id came from the builtin, remember the expression to give better + // diagnostic. If CoroIdExpr is nullptr, the coro.id was created by + // EmitCoroutineBody. + CallExpr const *CoroIdExpr = nullptr; +}; +} +} + +clang::CodeGen::CodeGenFunction::CGCoroInfo::CGCoroInfo() {} +CodeGenFunction::CGCoroInfo::~CGCoroInfo() {} + +static void createCoroData(CodeGenFunction &CGF, + CodeGenFunction::CGCoroInfo &CurCoro, + llvm::CallInst *CoroId, + CallExpr const *CoroIdExpr = nullptr) { + if (CurCoro.Data) { + if (CurCoro.Data->CoroIdExpr) + CGF.CGM.Error(CoroIdExpr->getLocStart(), + "only one __builtin_coro_id can be used in a function"); + else if (CoroIdExpr) + CGF.CGM.Error(CoroIdExpr->getLocStart(), + "__builtin_coro_id shall not be used in a C++ coroutine"); + else + llvm_unreachable("EmitCoroutineBodyStatement called twice?"); + + return; + } + + CurCoro.Data = std::unique_ptr<CGCoroData>(new CGCoroData); + CurCoro.Data->CoroId = CoroId; + CurCoro.Data->CoroIdExpr = CoroIdExpr; +} + +void CodeGenFunction::EmitCoroutineBody(const CoroutineBodyStmt &S) { + auto *NullPtr = llvm::ConstantPointerNull::get(Builder.getInt8PtrTy()); + auto &TI = CGM.getContext().getTargetInfo(); + unsigned NewAlign = TI.getNewAlign() / TI.getCharWidth(); + + auto *CoroId = Builder.CreateCall( + CGM.getIntrinsic(llvm::Intrinsic::coro_id), + {Builder.getInt32(NewAlign), NullPtr, NullPtr, NullPtr}); + createCoroData(*this, CurCoro, CoroId); + + EmitScalarExpr(S.getAllocate()); + // FIXME: Emit the rest of the coroutine. + EmitStmt(S.getDeallocate()); +} + +// Emit coroutine intrinsic and patch up arguments of the token type. +RValue CodeGenFunction::EmitCoroutineIntrinsic(const CallExpr *E, + unsigned int IID) { + SmallVector<llvm::Value *, 8> Args; + switch (IID) { + default: + break; + // The following three intrinsics take a token parameter referring to a token + // returned by earlier call to @llvm.coro.id. Since we cannot represent it in + // builtins, we patch it up here. + case llvm::Intrinsic::coro_alloc: + case llvm::Intrinsic::coro_begin: + case llvm::Intrinsic::coro_free: { + if (CurCoro.Data && CurCoro.Data->CoroId) { + Args.push_back(CurCoro.Data->CoroId); + break; + } + CGM.Error(E->getLocStart(), "this builtin expect that __builtin_coro_id has" + " been used earlier in this function"); + // Fallthrough to the next case to add TokenNone as the first argument. + } + // @llvm.coro.suspend takes a token parameter. Add token 'none' as the first + // argument. + case llvm::Intrinsic::coro_suspend: + Args.push_back(llvm::ConstantTokenNone::get(getLLVMContext())); + break; + } + for (auto &Arg : E->arguments()) + Args.push_back(EmitScalarExpr(Arg)); + + llvm::Value *F = CGM.getIntrinsic(IID); + llvm::CallInst *Call = Builder.CreateCall(F, Args); + + // If we see @llvm.coro.id remember it in the CoroData. We will update + // coro.alloc, coro.begin and coro.free intrinsics to refer to it. + if (IID == llvm::Intrinsic::coro_id) { + createCoroData(*this, CurCoro, Call, E); + } + return RValue::get(Call); +} |