mirror of
https://github.com/llvm/llvm-project.git
synced 2025-04-29 11:06:06 +00:00
e39ba04617
See the discussion in https://reviews.llvm.org/D100282. The coroutine marked always inline might not be inlined properly in current compiler support. Since the coroutine would be splitted into pieces. And the call to resume() and destroy() functions might be indirect call. Also the ramp function wouldn't get inlined under O0 due to pipeline ordering problems. It might be different to what users expects to. Emit a warning to tell it. This is what GCC does too: https://godbolt.org/z/7eajb1Gf8 Reviewed By: Quuxplusone Differential Revision: https://reviews.llvm.org/D115867
1788 lines
67 KiB
C++
1788 lines
67 KiB
C++
//===-- SemaCoroutine.cpp - Semantic Analysis for Coroutines --------------===//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file implements semantic analysis for C++ Coroutines.
|
|
//
|
|
// This file contains references to sections of the Coroutines TS, which
|
|
// can be found at http://wg21.link/coroutines.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "CoroutineStmtBuilder.h"
|
|
#include "clang/AST/ASTLambda.h"
|
|
#include "clang/AST/Decl.h"
|
|
#include "clang/AST/ExprCXX.h"
|
|
#include "clang/AST/StmtCXX.h"
|
|
#include "clang/Basic/Builtins.h"
|
|
#include "clang/Lex/Preprocessor.h"
|
|
#include "clang/Sema/Initialization.h"
|
|
#include "clang/Sema/Overload.h"
|
|
#include "clang/Sema/ScopeInfo.h"
|
|
#include "clang/Sema/SemaInternal.h"
|
|
#include "llvm/ADT/SmallSet.h"
|
|
|
|
using namespace clang;
|
|
using namespace sema;
|
|
|
|
static LookupResult lookupMember(Sema &S, const char *Name, CXXRecordDecl *RD,
|
|
SourceLocation Loc, bool &Res) {
|
|
DeclarationName DN = S.PP.getIdentifierInfo(Name);
|
|
LookupResult LR(S, DN, Loc, Sema::LookupMemberName);
|
|
// Suppress diagnostics when a private member is selected. The same warnings
|
|
// will be produced again when building the call.
|
|
LR.suppressDiagnostics();
|
|
Res = S.LookupQualifiedName(LR, RD);
|
|
return LR;
|
|
}
|
|
|
|
static bool lookupMember(Sema &S, const char *Name, CXXRecordDecl *RD,
|
|
SourceLocation Loc) {
|
|
bool Res;
|
|
lookupMember(S, Name, RD, Loc, Res);
|
|
return Res;
|
|
}
|
|
|
|
/// Look up the std::coroutine_traits<...>::promise_type for the given
|
|
/// function type.
|
|
static QualType lookupPromiseType(Sema &S, const FunctionDecl *FD,
|
|
SourceLocation KwLoc) {
|
|
const FunctionProtoType *FnType = FD->getType()->castAs<FunctionProtoType>();
|
|
const SourceLocation FuncLoc = FD->getLocation();
|
|
|
|
NamespaceDecl *CoroNamespace = nullptr;
|
|
ClassTemplateDecl *CoroTraits =
|
|
S.lookupCoroutineTraits(KwLoc, FuncLoc, CoroNamespace);
|
|
if (!CoroTraits) {
|
|
return QualType();
|
|
}
|
|
|
|
// Form template argument list for coroutine_traits<R, P1, P2, ...> according
|
|
// to [dcl.fct.def.coroutine]3
|
|
TemplateArgumentListInfo Args(KwLoc, KwLoc);
|
|
auto AddArg = [&](QualType T) {
|
|
Args.addArgument(TemplateArgumentLoc(
|
|
TemplateArgument(T), S.Context.getTrivialTypeSourceInfo(T, KwLoc)));
|
|
};
|
|
AddArg(FnType->getReturnType());
|
|
// If the function is a non-static member function, add the type
|
|
// of the implicit object parameter before the formal parameters.
|
|
if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) {
|
|
if (MD->isInstance()) {
|
|
// [over.match.funcs]4
|
|
// For non-static member functions, the type of the implicit object
|
|
// parameter is
|
|
// -- "lvalue reference to cv X" for functions declared without a
|
|
// ref-qualifier or with the & ref-qualifier
|
|
// -- "rvalue reference to cv X" for functions declared with the &&
|
|
// ref-qualifier
|
|
QualType T = MD->getThisType()->castAs<PointerType>()->getPointeeType();
|
|
T = FnType->getRefQualifier() == RQ_RValue
|
|
? S.Context.getRValueReferenceType(T)
|
|
: S.Context.getLValueReferenceType(T, /*SpelledAsLValue*/ true);
|
|
AddArg(T);
|
|
}
|
|
}
|
|
for (QualType T : FnType->getParamTypes())
|
|
AddArg(T);
|
|
|
|
// Build the template-id.
|
|
QualType CoroTrait =
|
|
S.CheckTemplateIdType(TemplateName(CoroTraits), KwLoc, Args);
|
|
if (CoroTrait.isNull())
|
|
return QualType();
|
|
if (S.RequireCompleteType(KwLoc, CoroTrait,
|
|
diag::err_coroutine_type_missing_specialization))
|
|
return QualType();
|
|
|
|
auto *RD = CoroTrait->getAsCXXRecordDecl();
|
|
assert(RD && "specialization of class template is not a class?");
|
|
|
|
// Look up the ::promise_type member.
|
|
LookupResult R(S, &S.PP.getIdentifierTable().get("promise_type"), KwLoc,
|
|
Sema::LookupOrdinaryName);
|
|
S.LookupQualifiedName(R, RD);
|
|
auto *Promise = R.getAsSingle<TypeDecl>();
|
|
if (!Promise) {
|
|
S.Diag(FuncLoc,
|
|
diag::err_implied_std_coroutine_traits_promise_type_not_found)
|
|
<< RD;
|
|
return QualType();
|
|
}
|
|
// The promise type is required to be a class type.
|
|
QualType PromiseType = S.Context.getTypeDeclType(Promise);
|
|
|
|
auto buildElaboratedType = [&]() {
|
|
auto *NNS = NestedNameSpecifier::Create(S.Context, nullptr, CoroNamespace);
|
|
NNS = NestedNameSpecifier::Create(S.Context, NNS, false,
|
|
CoroTrait.getTypePtr());
|
|
return S.Context.getElaboratedType(ETK_None, NNS, PromiseType);
|
|
};
|
|
|
|
if (!PromiseType->getAsCXXRecordDecl()) {
|
|
S.Diag(FuncLoc,
|
|
diag::err_implied_std_coroutine_traits_promise_type_not_class)
|
|
<< buildElaboratedType();
|
|
return QualType();
|
|
}
|
|
if (S.RequireCompleteType(FuncLoc, buildElaboratedType(),
|
|
diag::err_coroutine_promise_type_incomplete))
|
|
return QualType();
|
|
|
|
return PromiseType;
|
|
}
|
|
|
|
/// Look up the std::coroutine_handle<PromiseType>.
|
|
static QualType lookupCoroutineHandleType(Sema &S, QualType PromiseType,
|
|
SourceLocation Loc) {
|
|
if (PromiseType.isNull())
|
|
return QualType();
|
|
|
|
NamespaceDecl *CoroNamespace = S.getCachedCoroNamespace();
|
|
assert(CoroNamespace && "Should already be diagnosed");
|
|
|
|
LookupResult Result(S, &S.PP.getIdentifierTable().get("coroutine_handle"),
|
|
Loc, Sema::LookupOrdinaryName);
|
|
if (!S.LookupQualifiedName(Result, CoroNamespace)) {
|
|
S.Diag(Loc, diag::err_implied_coroutine_type_not_found)
|
|
<< "std::coroutine_handle";
|
|
return QualType();
|
|
}
|
|
|
|
ClassTemplateDecl *CoroHandle = Result.getAsSingle<ClassTemplateDecl>();
|
|
if (!CoroHandle) {
|
|
Result.suppressDiagnostics();
|
|
// We found something weird. Complain about the first thing we found.
|
|
NamedDecl *Found = *Result.begin();
|
|
S.Diag(Found->getLocation(), diag::err_malformed_std_coroutine_handle);
|
|
return QualType();
|
|
}
|
|
|
|
// Form template argument list for coroutine_handle<Promise>.
|
|
TemplateArgumentListInfo Args(Loc, Loc);
|
|
Args.addArgument(TemplateArgumentLoc(
|
|
TemplateArgument(PromiseType),
|
|
S.Context.getTrivialTypeSourceInfo(PromiseType, Loc)));
|
|
|
|
// Build the template-id.
|
|
QualType CoroHandleType =
|
|
S.CheckTemplateIdType(TemplateName(CoroHandle), Loc, Args);
|
|
if (CoroHandleType.isNull())
|
|
return QualType();
|
|
if (S.RequireCompleteType(Loc, CoroHandleType,
|
|
diag::err_coroutine_type_missing_specialization))
|
|
return QualType();
|
|
|
|
return CoroHandleType;
|
|
}
|
|
|
|
static bool isValidCoroutineContext(Sema &S, SourceLocation Loc,
|
|
StringRef Keyword) {
|
|
// [expr.await]p2 dictates that 'co_await' and 'co_yield' must be used within
|
|
// a function body.
|
|
// FIXME: This also covers [expr.await]p2: "An await-expression shall not
|
|
// appear in a default argument." But the diagnostic QoI here could be
|
|
// improved to inform the user that default arguments specifically are not
|
|
// allowed.
|
|
auto *FD = dyn_cast<FunctionDecl>(S.CurContext);
|
|
if (!FD) {
|
|
S.Diag(Loc, isa<ObjCMethodDecl>(S.CurContext)
|
|
? diag::err_coroutine_objc_method
|
|
: diag::err_coroutine_outside_function) << Keyword;
|
|
return false;
|
|
}
|
|
|
|
// An enumeration for mapping the diagnostic type to the correct diagnostic
|
|
// selection index.
|
|
enum InvalidFuncDiag {
|
|
DiagCtor = 0,
|
|
DiagDtor,
|
|
DiagMain,
|
|
DiagConstexpr,
|
|
DiagAutoRet,
|
|
DiagVarargs,
|
|
DiagConsteval,
|
|
};
|
|
bool Diagnosed = false;
|
|
auto DiagInvalid = [&](InvalidFuncDiag ID) {
|
|
S.Diag(Loc, diag::err_coroutine_invalid_func_context) << ID << Keyword;
|
|
Diagnosed = true;
|
|
return false;
|
|
};
|
|
|
|
// Diagnose when a constructor, destructor
|
|
// or the function 'main' are declared as a coroutine.
|
|
auto *MD = dyn_cast<CXXMethodDecl>(FD);
|
|
// [class.ctor]p11: "A constructor shall not be a coroutine."
|
|
if (MD && isa<CXXConstructorDecl>(MD))
|
|
return DiagInvalid(DiagCtor);
|
|
// [class.dtor]p17: "A destructor shall not be a coroutine."
|
|
else if (MD && isa<CXXDestructorDecl>(MD))
|
|
return DiagInvalid(DiagDtor);
|
|
// [basic.start.main]p3: "The function main shall not be a coroutine."
|
|
else if (FD->isMain())
|
|
return DiagInvalid(DiagMain);
|
|
|
|
// Emit a diagnostics for each of the following conditions which is not met.
|
|
// [expr.const]p2: "An expression e is a core constant expression unless the
|
|
// evaluation of e [...] would evaluate one of the following expressions:
|
|
// [...] an await-expression [...] a yield-expression."
|
|
if (FD->isConstexpr())
|
|
DiagInvalid(FD->isConsteval() ? DiagConsteval : DiagConstexpr);
|
|
// [dcl.spec.auto]p15: "A function declared with a return type that uses a
|
|
// placeholder type shall not be a coroutine."
|
|
if (FD->getReturnType()->isUndeducedType())
|
|
DiagInvalid(DiagAutoRet);
|
|
// [dcl.fct.def.coroutine]p1
|
|
// The parameter-declaration-clause of the coroutine shall not terminate with
|
|
// an ellipsis that is not part of a parameter-declaration.
|
|
if (FD->isVariadic())
|
|
DiagInvalid(DiagVarargs);
|
|
|
|
return !Diagnosed;
|
|
}
|
|
|
|
static ExprResult buildOperatorCoawaitLookupExpr(Sema &SemaRef, Scope *S,
|
|
SourceLocation Loc) {
|
|
DeclarationName OpName =
|
|
SemaRef.Context.DeclarationNames.getCXXOperatorName(OO_Coawait);
|
|
LookupResult Operators(SemaRef, OpName, SourceLocation(),
|
|
Sema::LookupOperatorName);
|
|
SemaRef.LookupName(Operators, S);
|
|
|
|
assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous");
|
|
const auto &Functions = Operators.asUnresolvedSet();
|
|
bool IsOverloaded =
|
|
Functions.size() > 1 ||
|
|
(Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin()));
|
|
Expr *CoawaitOp = UnresolvedLookupExpr::Create(
|
|
SemaRef.Context, /*NamingClass*/ nullptr, NestedNameSpecifierLoc(),
|
|
DeclarationNameInfo(OpName, Loc), /*RequiresADL*/ true, IsOverloaded,
|
|
Functions.begin(), Functions.end());
|
|
assert(CoawaitOp);
|
|
return CoawaitOp;
|
|
}
|
|
|
|
/// Build a call to 'operator co_await' if there is a suitable operator for
|
|
/// the given expression.
|
|
static ExprResult buildOperatorCoawaitCall(Sema &SemaRef, SourceLocation Loc,
|
|
Expr *E,
|
|
UnresolvedLookupExpr *Lookup) {
|
|
UnresolvedSet<16> Functions;
|
|
Functions.append(Lookup->decls_begin(), Lookup->decls_end());
|
|
return SemaRef.CreateOverloadedUnaryOp(Loc, UO_Coawait, Functions, E);
|
|
}
|
|
|
|
static ExprResult buildOperatorCoawaitCall(Sema &SemaRef, Scope *S,
|
|
SourceLocation Loc, Expr *E) {
|
|
ExprResult R = buildOperatorCoawaitLookupExpr(SemaRef, S, Loc);
|
|
if (R.isInvalid())
|
|
return ExprError();
|
|
return buildOperatorCoawaitCall(SemaRef, Loc, E,
|
|
cast<UnresolvedLookupExpr>(R.get()));
|
|
}
|
|
|
|
static ExprResult buildCoroutineHandle(Sema &S, QualType PromiseType,
|
|
SourceLocation Loc) {
|
|
QualType CoroHandleType = lookupCoroutineHandleType(S, PromiseType, Loc);
|
|
if (CoroHandleType.isNull())
|
|
return ExprError();
|
|
|
|
DeclContext *LookupCtx = S.computeDeclContext(CoroHandleType);
|
|
LookupResult Found(S, &S.PP.getIdentifierTable().get("from_address"), Loc,
|
|
Sema::LookupOrdinaryName);
|
|
if (!S.LookupQualifiedName(Found, LookupCtx)) {
|
|
S.Diag(Loc, diag::err_coroutine_handle_missing_member)
|
|
<< "from_address";
|
|
return ExprError();
|
|
}
|
|
|
|
Expr *FramePtr =
|
|
S.BuildBuiltinCallExpr(Loc, Builtin::BI__builtin_coro_frame, {});
|
|
|
|
CXXScopeSpec SS;
|
|
ExprResult FromAddr =
|
|
S.BuildDeclarationNameExpr(SS, Found, /*NeedsADL=*/false);
|
|
if (FromAddr.isInvalid())
|
|
return ExprError();
|
|
|
|
return S.BuildCallExpr(nullptr, FromAddr.get(), Loc, FramePtr, Loc);
|
|
}
|
|
|
|
struct ReadySuspendResumeResult {
|
|
enum AwaitCallType { ACT_Ready, ACT_Suspend, ACT_Resume };
|
|
Expr *Results[3];
|
|
OpaqueValueExpr *OpaqueValue;
|
|
bool IsInvalid;
|
|
};
|
|
|
|
static ExprResult buildMemberCall(Sema &S, Expr *Base, SourceLocation Loc,
|
|
StringRef Name, MultiExprArg Args) {
|
|
DeclarationNameInfo NameInfo(&S.PP.getIdentifierTable().get(Name), Loc);
|
|
|
|
// FIXME: Fix BuildMemberReferenceExpr to take a const CXXScopeSpec&.
|
|
CXXScopeSpec SS;
|
|
ExprResult Result = S.BuildMemberReferenceExpr(
|
|
Base, Base->getType(), Loc, /*IsPtr=*/false, SS,
|
|
SourceLocation(), nullptr, NameInfo, /*TemplateArgs=*/nullptr,
|
|
/*Scope=*/nullptr);
|
|
if (Result.isInvalid())
|
|
return ExprError();
|
|
|
|
// We meant exactly what we asked for. No need for typo correction.
|
|
if (auto *TE = dyn_cast<TypoExpr>(Result.get())) {
|
|
S.clearDelayedTypo(TE);
|
|
S.Diag(Loc, diag::err_no_member)
|
|
<< NameInfo.getName() << Base->getType()->getAsCXXRecordDecl()
|
|
<< Base->getSourceRange();
|
|
return ExprError();
|
|
}
|
|
|
|
return S.BuildCallExpr(nullptr, Result.get(), Loc, Args, Loc, nullptr);
|
|
}
|
|
|
|
// See if return type is coroutine-handle and if so, invoke builtin coro-resume
|
|
// on its address. This is to enable experimental support for coroutine-handle
|
|
// returning await_suspend that results in a guaranteed tail call to the target
|
|
// coroutine.
|
|
static Expr *maybeTailCall(Sema &S, QualType RetType, Expr *E,
|
|
SourceLocation Loc) {
|
|
if (RetType->isReferenceType())
|
|
return nullptr;
|
|
Type const *T = RetType.getTypePtr();
|
|
if (!T->isClassType() && !T->isStructureType())
|
|
return nullptr;
|
|
|
|
// FIXME: Add convertability check to coroutine_handle<>. Possibly via
|
|
// EvaluateBinaryTypeTrait(BTT_IsConvertible, ...) which is at the moment
|
|
// a private function in SemaExprCXX.cpp
|
|
|
|
ExprResult AddressExpr = buildMemberCall(S, E, Loc, "address", None);
|
|
if (AddressExpr.isInvalid())
|
|
return nullptr;
|
|
|
|
Expr *JustAddress = AddressExpr.get();
|
|
|
|
// Check that the type of AddressExpr is void*
|
|
if (!JustAddress->getType().getTypePtr()->isVoidPointerType())
|
|
S.Diag(cast<CallExpr>(JustAddress)->getCalleeDecl()->getLocation(),
|
|
diag::warn_coroutine_handle_address_invalid_return_type)
|
|
<< JustAddress->getType();
|
|
|
|
// Clean up temporary objects so that they don't live across suspension points
|
|
// unnecessarily. We choose to clean up before the call to
|
|
// __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);
|
|
}
|
|
|
|
/// Build calls to await_ready, await_suspend, and await_resume for a co_await
|
|
/// expression.
|
|
/// The generated AST tries to clean up temporary objects as early as
|
|
/// possible so that they don't live across suspension points if possible.
|
|
/// Having temporary objects living across suspension points unnecessarily can
|
|
/// lead to large frame size, and also lead to memory corruptions if the
|
|
/// coroutine frame is destroyed after coming back from suspension. This is done
|
|
/// by wrapping both the await_ready call and the await_suspend call with
|
|
/// ExprWithCleanups. In the end of this function, we also need to explicitly
|
|
/// set cleanup state so that the CoawaitExpr is also wrapped with an
|
|
/// ExprWithCleanups to clean up the awaiter associated with the co_await
|
|
/// expression.
|
|
static ReadySuspendResumeResult buildCoawaitCalls(Sema &S, VarDecl *CoroPromise,
|
|
SourceLocation Loc, Expr *E) {
|
|
OpaqueValueExpr *Operand = new (S.Context)
|
|
OpaqueValueExpr(Loc, E->getType(), VK_LValue, E->getObjectKind(), E);
|
|
|
|
// Assume valid until we see otherwise.
|
|
// Further operations are responsible for setting IsInalid to true.
|
|
ReadySuspendResumeResult Calls = {{}, Operand, /*IsInvalid=*/false};
|
|
|
|
using ACT = ReadySuspendResumeResult::AwaitCallType;
|
|
|
|
auto BuildSubExpr = [&](ACT CallType, StringRef Func,
|
|
MultiExprArg Arg) -> Expr * {
|
|
ExprResult Result = buildMemberCall(S, Operand, Loc, Func, Arg);
|
|
if (Result.isInvalid()) {
|
|
Calls.IsInvalid = true;
|
|
return nullptr;
|
|
}
|
|
Calls.Results[CallType] = Result.get();
|
|
return Result.get();
|
|
};
|
|
|
|
CallExpr *AwaitReady =
|
|
cast_or_null<CallExpr>(BuildSubExpr(ACT::ACT_Ready, "await_ready", None));
|
|
if (!AwaitReady)
|
|
return Calls;
|
|
if (!AwaitReady->getType()->isDependentType()) {
|
|
// [expr.await]p3 [...]
|
|
// — await-ready is the expression e.await_ready(), contextually converted
|
|
// to bool.
|
|
ExprResult Conv = S.PerformContextuallyConvertToBool(AwaitReady);
|
|
if (Conv.isInvalid()) {
|
|
S.Diag(AwaitReady->getDirectCallee()->getBeginLoc(),
|
|
diag::note_await_ready_no_bool_conversion);
|
|
S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required)
|
|
<< AwaitReady->getDirectCallee() << E->getSourceRange();
|
|
Calls.IsInvalid = true;
|
|
} else
|
|
Calls.Results[ACT::ACT_Ready] = S.MaybeCreateExprWithCleanups(Conv.get());
|
|
}
|
|
|
|
ExprResult CoroHandleRes =
|
|
buildCoroutineHandle(S, CoroPromise->getType(), Loc);
|
|
if (CoroHandleRes.isInvalid()) {
|
|
Calls.IsInvalid = true;
|
|
return Calls;
|
|
}
|
|
Expr *CoroHandle = CoroHandleRes.get();
|
|
CallExpr *AwaitSuspend = cast_or_null<CallExpr>(
|
|
BuildSubExpr(ACT::ACT_Suspend, "await_suspend", CoroHandle));
|
|
if (!AwaitSuspend)
|
|
return Calls;
|
|
if (!AwaitSuspend->getType()->isDependentType()) {
|
|
// [expr.await]p3 [...]
|
|
// - await-suspend is the expression e.await_suspend(h), which shall be
|
|
// a prvalue of type void, bool, or std::coroutine_handle<Z> for some
|
|
// type Z.
|
|
QualType RetType = AwaitSuspend->getCallReturnType(S.Context);
|
|
|
|
// Experimental support for coroutine_handle returning await_suspend.
|
|
if (Expr *TailCallSuspend =
|
|
maybeTailCall(S, RetType, AwaitSuspend, Loc))
|
|
// Note that we don't wrap the expression with ExprWithCleanups here
|
|
// because that might interfere with tailcall contract (e.g. inserting
|
|
// clean up instructions in-between tailcall and return). Instead
|
|
// ExprWithCleanups is wrapped within maybeTailCall() prior to the resume
|
|
// call.
|
|
Calls.Results[ACT::ACT_Suspend] = TailCallSuspend;
|
|
else {
|
|
// non-class prvalues always have cv-unqualified types
|
|
if (RetType->isReferenceType() ||
|
|
(!RetType->isBooleanType() && !RetType->isVoidType())) {
|
|
S.Diag(AwaitSuspend->getCalleeDecl()->getLocation(),
|
|
diag::err_await_suspend_invalid_return_type)
|
|
<< RetType;
|
|
S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required)
|
|
<< AwaitSuspend->getDirectCallee();
|
|
Calls.IsInvalid = true;
|
|
} else
|
|
Calls.Results[ACT::ACT_Suspend] =
|
|
S.MaybeCreateExprWithCleanups(AwaitSuspend);
|
|
}
|
|
}
|
|
|
|
BuildSubExpr(ACT::ACT_Resume, "await_resume", None);
|
|
|
|
// Make sure the awaiter object gets a chance to be cleaned up.
|
|
S.Cleanup.setExprNeedsCleanups(true);
|
|
|
|
return Calls;
|
|
}
|
|
|
|
static ExprResult buildPromiseCall(Sema &S, VarDecl *Promise,
|
|
SourceLocation Loc, StringRef Name,
|
|
MultiExprArg Args) {
|
|
|
|
// Form a reference to the promise.
|
|
ExprResult PromiseRef = S.BuildDeclRefExpr(
|
|
Promise, Promise->getType().getNonReferenceType(), VK_LValue, Loc);
|
|
if (PromiseRef.isInvalid())
|
|
return ExprError();
|
|
|
|
return buildMemberCall(S, PromiseRef.get(), Loc, Name, Args);
|
|
}
|
|
|
|
VarDecl *Sema::buildCoroutinePromise(SourceLocation Loc) {
|
|
assert(isa<FunctionDecl>(CurContext) && "not in a function scope");
|
|
auto *FD = cast<FunctionDecl>(CurContext);
|
|
bool IsThisDependentType = [&] {
|
|
if (auto *MD = dyn_cast_or_null<CXXMethodDecl>(FD))
|
|
return MD->isInstance() && MD->getThisType()->isDependentType();
|
|
else
|
|
return false;
|
|
}();
|
|
|
|
QualType T = FD->getType()->isDependentType() || IsThisDependentType
|
|
? Context.DependentTy
|
|
: lookupPromiseType(*this, FD, Loc);
|
|
if (T.isNull())
|
|
return nullptr;
|
|
|
|
auto *VD = VarDecl::Create(Context, FD, FD->getLocation(), FD->getLocation(),
|
|
&PP.getIdentifierTable().get("__promise"), T,
|
|
Context.getTrivialTypeSourceInfo(T, Loc), SC_None);
|
|
VD->setImplicit();
|
|
CheckVariableDeclarationType(VD);
|
|
if (VD->isInvalidDecl())
|
|
return nullptr;
|
|
|
|
auto *ScopeInfo = getCurFunction();
|
|
|
|
// Build a list of arguments, based on the coroutine function's arguments,
|
|
// that if present will be passed to the promise type's constructor.
|
|
llvm::SmallVector<Expr *, 4> CtorArgExprs;
|
|
|
|
// Add implicit object parameter.
|
|
if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) {
|
|
if (MD->isInstance() && !isLambdaCallOperator(MD)) {
|
|
ExprResult ThisExpr = ActOnCXXThis(Loc);
|
|
if (ThisExpr.isInvalid())
|
|
return nullptr;
|
|
ThisExpr = CreateBuiltinUnaryOp(Loc, UO_Deref, ThisExpr.get());
|
|
if (ThisExpr.isInvalid())
|
|
return nullptr;
|
|
CtorArgExprs.push_back(ThisExpr.get());
|
|
}
|
|
}
|
|
|
|
// Add the coroutine function's parameters.
|
|
auto &Moves = ScopeInfo->CoroutineParameterMoves;
|
|
for (auto *PD : FD->parameters()) {
|
|
if (PD->getType()->isDependentType())
|
|
continue;
|
|
|
|
auto RefExpr = ExprEmpty();
|
|
auto Move = Moves.find(PD);
|
|
assert(Move != Moves.end() &&
|
|
"Coroutine function parameter not inserted into move map");
|
|
// If a reference to the function parameter exists in the coroutine
|
|
// frame, use that reference.
|
|
auto *MoveDecl =
|
|
cast<VarDecl>(cast<DeclStmt>(Move->second)->getSingleDecl());
|
|
RefExpr =
|
|
BuildDeclRefExpr(MoveDecl, MoveDecl->getType().getNonReferenceType(),
|
|
ExprValueKind::VK_LValue, FD->getLocation());
|
|
if (RefExpr.isInvalid())
|
|
return nullptr;
|
|
CtorArgExprs.push_back(RefExpr.get());
|
|
}
|
|
|
|
// If we have a non-zero number of constructor arguments, try to use them.
|
|
// Otherwise, fall back to the promise type's default constructor.
|
|
if (!CtorArgExprs.empty()) {
|
|
// Create an initialization sequence for the promise type using the
|
|
// constructor arguments, wrapped in a parenthesized list expression.
|
|
Expr *PLE = ParenListExpr::Create(Context, FD->getLocation(),
|
|
CtorArgExprs, FD->getLocation());
|
|
InitializedEntity Entity = InitializedEntity::InitializeVariable(VD);
|
|
InitializationKind Kind = InitializationKind::CreateForInit(
|
|
VD->getLocation(), /*DirectInit=*/true, PLE);
|
|
InitializationSequence InitSeq(*this, Entity, Kind, CtorArgExprs,
|
|
/*TopLevelOfInitList=*/false,
|
|
/*TreatUnavailableAsInvalid=*/false);
|
|
|
|
// [dcl.fct.def.coroutine]5.7
|
|
// promise-constructor-arguments is determined as follows: overload
|
|
// resolution is performed on a promise constructor call created by
|
|
// assembling an argument list q_1 ... q_n . If a viable constructor is
|
|
// found ([over.match.viable]), then promise-constructor-arguments is ( q_1
|
|
// , ..., q_n ), otherwise promise-constructor-arguments is empty.
|
|
if (InitSeq) {
|
|
ExprResult Result = InitSeq.Perform(*this, Entity, Kind, CtorArgExprs);
|
|
if (Result.isInvalid()) {
|
|
VD->setInvalidDecl();
|
|
} else if (Result.get()) {
|
|
VD->setInit(MaybeCreateExprWithCleanups(Result.get()));
|
|
VD->setInitStyle(VarDecl::CallInit);
|
|
CheckCompleteVariableDeclaration(VD);
|
|
}
|
|
} else
|
|
ActOnUninitializedDecl(VD);
|
|
} else
|
|
ActOnUninitializedDecl(VD);
|
|
|
|
FD->addDecl(VD);
|
|
return VD;
|
|
}
|
|
|
|
/// Check that this is a context in which a coroutine suspension can appear.
|
|
static FunctionScopeInfo *checkCoroutineContext(Sema &S, SourceLocation Loc,
|
|
StringRef Keyword,
|
|
bool IsImplicit = false) {
|
|
if (!isValidCoroutineContext(S, Loc, Keyword))
|
|
return nullptr;
|
|
|
|
assert(isa<FunctionDecl>(S.CurContext) && "not in a function scope");
|
|
|
|
auto *ScopeInfo = S.getCurFunction();
|
|
assert(ScopeInfo && "missing function scope for function");
|
|
|
|
if (ScopeInfo->FirstCoroutineStmtLoc.isInvalid() && !IsImplicit)
|
|
ScopeInfo->setFirstCoroutineStmt(Loc, Keyword);
|
|
|
|
if (ScopeInfo->CoroutinePromise)
|
|
return ScopeInfo;
|
|
|
|
if (!S.buildCoroutineParameterMoves(Loc))
|
|
return nullptr;
|
|
|
|
ScopeInfo->CoroutinePromise = S.buildCoroutinePromise(Loc);
|
|
if (!ScopeInfo->CoroutinePromise)
|
|
return nullptr;
|
|
|
|
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 void checkNoThrow(Sema &S, const Stmt *E,
|
|
llvm::SmallPtrSetImpl<const Decl *> &ThrowingDecls) {
|
|
auto checkDeclNoexcept = [&](const Decl *D, bool IsDtor = false) {
|
|
// 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)) {
|
|
if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
|
|
// co_await promise.final_suspend() could end up calling
|
|
// __builtin_coro_resume for symmetric transfer if await_suspend()
|
|
// returns a handle. In that case, even __builtin_coro_resume is not
|
|
// declared as noexcept and may throw, it does not throw _into_ the
|
|
// coroutine that just suspended, but rather throws back out from
|
|
// whoever called coroutine_handle::resume(), hence we claim that
|
|
// logically it does not throw.
|
|
if (FD->getBuiltinID() == Builtin::BI__builtin_coro_resume)
|
|
return;
|
|
}
|
|
if (ThrowingDecls.empty()) {
|
|
// [dcl.fct.def.coroutine]p15
|
|
// The expression co_await promise.final_suspend() shall not be
|
|
// potentially-throwing ([except.spec]).
|
|
//
|
|
// First time seeing an error, emit the error message.
|
|
S.Diag(cast<FunctionDecl>(S.CurContext)->getLocation(),
|
|
diag::err_coroutine_promise_final_suspend_requires_nothrow);
|
|
}
|
|
ThrowingDecls.insert(D);
|
|
}
|
|
};
|
|
|
|
if (auto *CE = dyn_cast<CXXConstructExpr>(E)) {
|
|
CXXConstructorDecl *Ctor = CE->getConstructor();
|
|
checkDeclNoexcept(Ctor);
|
|
// Check the corresponding destructor of the constructor.
|
|
checkDeclNoexcept(Ctor->getParent()->getDestructor(), /*IsDtor=*/true);
|
|
} else if (auto *CE = dyn_cast<CallExpr>(E)) {
|
|
if (CE->isTypeDependent())
|
|
return;
|
|
|
|
checkDeclNoexcept(CE->getCalleeDecl());
|
|
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());
|
|
checkDeclNoexcept(dyn_cast<CXXRecordDecl>(T->getDecl())->getDestructor(),
|
|
/*IsDtor=*/true);
|
|
}
|
|
} else
|
|
for (const auto *Child : E->children()) {
|
|
if (!Child)
|
|
continue;
|
|
checkNoThrow(S, Child, ThrowingDecls);
|
|
}
|
|
}
|
|
|
|
bool Sema::checkFinalSuspendNoThrow(const Stmt *FinalSuspend) {
|
|
llvm::SmallPtrSet<const Decl *, 4> ThrowingDecls;
|
|
// We first collect all declarations that should not throw but not declared
|
|
// with noexcept. We then sort them based on the location before printing.
|
|
// This is to avoid emitting the same note multiple times on the same
|
|
// declaration, and also provide a deterministic order for the messages.
|
|
checkNoThrow(*this, FinalSuspend, ThrowingDecls);
|
|
auto SortedDecls = llvm::SmallVector<const Decl *, 4>{ThrowingDecls.begin(),
|
|
ThrowingDecls.end()};
|
|
sort(SortedDecls, [](const Decl *A, const Decl *B) {
|
|
return A->getEndLoc() < B->getEndLoc();
|
|
});
|
|
for (const auto *D : SortedDecls) {
|
|
Diag(D->getEndLoc(), diag::note_coroutine_function_declare_noexcept);
|
|
}
|
|
return ThrowingDecls.empty();
|
|
}
|
|
|
|
bool Sema::ActOnCoroutineBodyStart(Scope *SC, SourceLocation KWLoc,
|
|
StringRef Keyword) {
|
|
if (!checkCoroutineContext(*this, KWLoc, Keyword))
|
|
return false;
|
|
auto *ScopeInfo = getCurFunction();
|
|
assert(ScopeInfo->CoroutinePromise);
|
|
|
|
// If we have existing coroutine statements then we have already built
|
|
// the initial and final suspend points.
|
|
if (!ScopeInfo->NeedsCoroutineSuspends)
|
|
return true;
|
|
|
|
ScopeInfo->setNeedsCoroutineSuspends(false);
|
|
|
|
auto *Fn = cast<FunctionDecl>(CurContext);
|
|
SourceLocation Loc = Fn->getLocation();
|
|
// Build the initial suspend point
|
|
auto buildSuspends = [&](StringRef Name) mutable -> StmtResult {
|
|
ExprResult Suspend =
|
|
buildPromiseCall(*this, ScopeInfo->CoroutinePromise, Loc, Name, None);
|
|
if (Suspend.isInvalid())
|
|
return StmtError();
|
|
Suspend = buildOperatorCoawaitCall(*this, SC, Loc, Suspend.get());
|
|
if (Suspend.isInvalid())
|
|
return StmtError();
|
|
Suspend = BuildResolvedCoawaitExpr(Loc, Suspend.get(),
|
|
/*IsImplicit*/ true);
|
|
Suspend = ActOnFinishFullExpr(Suspend.get(), /*DiscardedValue*/ false);
|
|
if (Suspend.isInvalid()) {
|
|
Diag(Loc, diag::note_coroutine_promise_suspend_implicitly_required)
|
|
<< ((Name == "initial_suspend") ? 0 : 1);
|
|
Diag(KWLoc, diag::note_declared_coroutine_here) << Keyword;
|
|
return StmtError();
|
|
}
|
|
return cast<Stmt>(Suspend.get());
|
|
};
|
|
|
|
StmtResult InitSuspend = buildSuspends("initial_suspend");
|
|
if (InitSuspend.isInvalid())
|
|
return true;
|
|
|
|
StmtResult FinalSuspend = buildSuspends("final_suspend");
|
|
if (FinalSuspend.isInvalid() || !checkFinalSuspendNoThrow(FinalSuspend.get()))
|
|
return true;
|
|
|
|
ScopeInfo->setCoroutineSuspends(InitSuspend.get(), FinalSuspend.get());
|
|
|
|
return true;
|
|
}
|
|
|
|
// Recursively walks up the scope hierarchy until either a 'catch' or a function
|
|
// scope is found, whichever comes first.
|
|
static bool isWithinCatchScope(Scope *S) {
|
|
// 'co_await' and 'co_yield' keywords are disallowed within catch blocks, but
|
|
// lambdas that use 'co_await' are allowed. The loop below ends when a
|
|
// function scope is found in order to ensure the following behavior:
|
|
//
|
|
// void foo() { // <- function scope
|
|
// try { //
|
|
// co_await x; // <- 'co_await' is OK within a function scope
|
|
// } catch { // <- catch scope
|
|
// co_await x; // <- 'co_await' is not OK within a catch scope
|
|
// []() { // <- function scope
|
|
// co_await x; // <- 'co_await' is OK within a function scope
|
|
// }();
|
|
// }
|
|
// }
|
|
while (S && !(S->getFlags() & Scope::FnScope)) {
|
|
if (S->getFlags() & Scope::CatchScope)
|
|
return true;
|
|
S = S->getParent();
|
|
}
|
|
return false;
|
|
}
|
|
|
|
// [expr.await]p2, emphasis added: "An await-expression shall appear only in
|
|
// a *potentially evaluated* expression within the compound-statement of a
|
|
// function-body *outside of a handler* [...] A context within a function
|
|
// where an await-expression can appear is called a suspension context of the
|
|
// function."
|
|
static void checkSuspensionContext(Sema &S, SourceLocation Loc,
|
|
StringRef Keyword) {
|
|
// First emphasis of [expr.await]p2: must be a potentially evaluated context.
|
|
// That is, 'co_await' and 'co_yield' cannot appear in subexpressions of
|
|
// \c sizeof.
|
|
if (S.isUnevaluatedContext())
|
|
S.Diag(Loc, diag::err_coroutine_unevaluated_context) << Keyword;
|
|
|
|
// Second emphasis of [expr.await]p2: must be outside of an exception handler.
|
|
if (isWithinCatchScope(S.getCurScope()))
|
|
S.Diag(Loc, diag::err_coroutine_within_handler) << Keyword;
|
|
}
|
|
|
|
ExprResult Sema::ActOnCoawaitExpr(Scope *S, SourceLocation Loc, Expr *E) {
|
|
if (!ActOnCoroutineBodyStart(S, Loc, "co_await")) {
|
|
CorrectDelayedTyposInExpr(E);
|
|
return ExprError();
|
|
}
|
|
|
|
checkSuspensionContext(*this, Loc, "co_await");
|
|
|
|
if (E->hasPlaceholderType()) {
|
|
ExprResult R = CheckPlaceholderExpr(E);
|
|
if (R.isInvalid()) return ExprError();
|
|
E = R.get();
|
|
}
|
|
ExprResult Lookup = buildOperatorCoawaitLookupExpr(*this, S, Loc);
|
|
if (Lookup.isInvalid())
|
|
return ExprError();
|
|
return BuildUnresolvedCoawaitExpr(Loc, E,
|
|
cast<UnresolvedLookupExpr>(Lookup.get()));
|
|
}
|
|
|
|
ExprResult Sema::BuildUnresolvedCoawaitExpr(SourceLocation Loc, Expr *E,
|
|
UnresolvedLookupExpr *Lookup) {
|
|
auto *FSI = checkCoroutineContext(*this, Loc, "co_await");
|
|
if (!FSI)
|
|
return ExprError();
|
|
|
|
if (E->hasPlaceholderType()) {
|
|
ExprResult R = CheckPlaceholderExpr(E);
|
|
if (R.isInvalid())
|
|
return ExprError();
|
|
E = R.get();
|
|
}
|
|
|
|
auto *Promise = FSI->CoroutinePromise;
|
|
if (Promise->getType()->isDependentType()) {
|
|
Expr *Res =
|
|
new (Context) DependentCoawaitExpr(Loc, Context.DependentTy, E, Lookup);
|
|
return Res;
|
|
}
|
|
|
|
auto *RD = Promise->getType()->getAsCXXRecordDecl();
|
|
if (lookupMember(*this, "await_transform", RD, Loc)) {
|
|
ExprResult R = buildPromiseCall(*this, Promise, Loc, "await_transform", E);
|
|
if (R.isInvalid()) {
|
|
Diag(Loc,
|
|
diag::note_coroutine_promise_implicit_await_transform_required_here)
|
|
<< E->getSourceRange();
|
|
return ExprError();
|
|
}
|
|
E = R.get();
|
|
}
|
|
ExprResult Awaitable = buildOperatorCoawaitCall(*this, Loc, E, Lookup);
|
|
if (Awaitable.isInvalid())
|
|
return ExprError();
|
|
|
|
return BuildResolvedCoawaitExpr(Loc, Awaitable.get());
|
|
}
|
|
|
|
ExprResult Sema::BuildResolvedCoawaitExpr(SourceLocation Loc, Expr *E,
|
|
bool IsImplicit) {
|
|
auto *Coroutine = checkCoroutineContext(*this, Loc, "co_await", IsImplicit);
|
|
if (!Coroutine)
|
|
return ExprError();
|
|
|
|
if (E->hasPlaceholderType()) {
|
|
ExprResult R = CheckPlaceholderExpr(E);
|
|
if (R.isInvalid()) return ExprError();
|
|
E = R.get();
|
|
}
|
|
|
|
if (E->getType()->isDependentType()) {
|
|
Expr *Res = new (Context)
|
|
CoawaitExpr(Loc, Context.DependentTy, E, IsImplicit);
|
|
return Res;
|
|
}
|
|
|
|
// If the expression is a temporary, materialize it as an lvalue so that we
|
|
// can use it multiple times.
|
|
if (E->isPRValue())
|
|
E = CreateMaterializeTemporaryExpr(E->getType(), E, true);
|
|
|
|
// The location of the `co_await` token cannot be used when constructing
|
|
// the member call expressions since it's before the location of `Expr`, which
|
|
// is used as the start of the member call expression.
|
|
SourceLocation CallLoc = E->getExprLoc();
|
|
|
|
// Build the await_ready, await_suspend, await_resume calls.
|
|
ReadySuspendResumeResult RSS = buildCoawaitCalls(
|
|
*this, Coroutine->CoroutinePromise, CallLoc, E);
|
|
if (RSS.IsInvalid)
|
|
return ExprError();
|
|
|
|
Expr *Res =
|
|
new (Context) CoawaitExpr(Loc, E, RSS.Results[0], RSS.Results[1],
|
|
RSS.Results[2], RSS.OpaqueValue, IsImplicit);
|
|
|
|
return Res;
|
|
}
|
|
|
|
ExprResult Sema::ActOnCoyieldExpr(Scope *S, SourceLocation Loc, Expr *E) {
|
|
if (!ActOnCoroutineBodyStart(S, Loc, "co_yield")) {
|
|
CorrectDelayedTyposInExpr(E);
|
|
return ExprError();
|
|
}
|
|
|
|
checkSuspensionContext(*this, Loc, "co_yield");
|
|
|
|
// Build yield_value call.
|
|
ExprResult Awaitable = buildPromiseCall(
|
|
*this, getCurFunction()->CoroutinePromise, Loc, "yield_value", E);
|
|
if (Awaitable.isInvalid())
|
|
return ExprError();
|
|
|
|
// Build 'operator co_await' call.
|
|
Awaitable = buildOperatorCoawaitCall(*this, S, Loc, Awaitable.get());
|
|
if (Awaitable.isInvalid())
|
|
return ExprError();
|
|
|
|
return BuildCoyieldExpr(Loc, Awaitable.get());
|
|
}
|
|
ExprResult Sema::BuildCoyieldExpr(SourceLocation Loc, Expr *E) {
|
|
auto *Coroutine = checkCoroutineContext(*this, Loc, "co_yield");
|
|
if (!Coroutine)
|
|
return ExprError();
|
|
|
|
if (E->hasPlaceholderType()) {
|
|
ExprResult R = CheckPlaceholderExpr(E);
|
|
if (R.isInvalid()) return ExprError();
|
|
E = R.get();
|
|
}
|
|
|
|
if (E->getType()->isDependentType()) {
|
|
Expr *Res = new (Context) CoyieldExpr(Loc, Context.DependentTy, E);
|
|
return Res;
|
|
}
|
|
|
|
// If the expression is a temporary, materialize it as an lvalue so that we
|
|
// can use it multiple times.
|
|
if (E->isPRValue())
|
|
E = CreateMaterializeTemporaryExpr(E->getType(), E, true);
|
|
|
|
// Build the await_ready, await_suspend, await_resume calls.
|
|
ReadySuspendResumeResult RSS = buildCoawaitCalls(
|
|
*this, Coroutine->CoroutinePromise, Loc, E);
|
|
if (RSS.IsInvalid)
|
|
return ExprError();
|
|
|
|
Expr *Res =
|
|
new (Context) CoyieldExpr(Loc, E, RSS.Results[0], RSS.Results[1],
|
|
RSS.Results[2], RSS.OpaqueValue);
|
|
|
|
return Res;
|
|
}
|
|
|
|
StmtResult Sema::ActOnCoreturnStmt(Scope *S, SourceLocation Loc, Expr *E) {
|
|
if (!ActOnCoroutineBodyStart(S, Loc, "co_return")) {
|
|
CorrectDelayedTyposInExpr(E);
|
|
return StmtError();
|
|
}
|
|
return BuildCoreturnStmt(Loc, E);
|
|
}
|
|
|
|
StmtResult Sema::BuildCoreturnStmt(SourceLocation Loc, Expr *E,
|
|
bool IsImplicit) {
|
|
auto *FSI = checkCoroutineContext(*this, Loc, "co_return", IsImplicit);
|
|
if (!FSI)
|
|
return StmtError();
|
|
|
|
if (E && E->hasPlaceholderType() &&
|
|
!E->hasPlaceholderType(BuiltinType::Overload)) {
|
|
ExprResult R = CheckPlaceholderExpr(E);
|
|
if (R.isInvalid()) return StmtError();
|
|
E = R.get();
|
|
}
|
|
|
|
VarDecl *Promise = FSI->CoroutinePromise;
|
|
ExprResult PC;
|
|
if (E && (isa<InitListExpr>(E) || !E->getType()->isVoidType())) {
|
|
getNamedReturnInfo(E, SimplerImplicitMoveMode::ForceOn);
|
|
PC = buildPromiseCall(*this, Promise, Loc, "return_value", E);
|
|
} else {
|
|
E = MakeFullDiscardedValueExpr(E).get();
|
|
PC = buildPromiseCall(*this, Promise, Loc, "return_void", None);
|
|
}
|
|
if (PC.isInvalid())
|
|
return StmtError();
|
|
|
|
Expr *PCE = ActOnFinishFullExpr(PC.get(), /*DiscardedValue*/ false).get();
|
|
|
|
Stmt *Res = new (Context) CoreturnStmt(Loc, E, PCE, IsImplicit);
|
|
return Res;
|
|
}
|
|
|
|
/// Look up the std::nothrow object.
|
|
static Expr *buildStdNoThrowDeclRef(Sema &S, SourceLocation Loc) {
|
|
NamespaceDecl *Std = S.getStdNamespace();
|
|
assert(Std && "Should already be diagnosed");
|
|
|
|
LookupResult Result(S, &S.PP.getIdentifierTable().get("nothrow"), Loc,
|
|
Sema::LookupOrdinaryName);
|
|
if (!S.LookupQualifiedName(Result, Std)) {
|
|
// <coroutine> is not requred to include <new>, so we couldn't omit
|
|
// the check here.
|
|
S.Diag(Loc, diag::err_implicit_coroutine_std_nothrow_type_not_found);
|
|
return nullptr;
|
|
}
|
|
|
|
auto *VD = Result.getAsSingle<VarDecl>();
|
|
if (!VD) {
|
|
Result.suppressDiagnostics();
|
|
// We found something weird. Complain about the first thing we found.
|
|
NamedDecl *Found = *Result.begin();
|
|
S.Diag(Found->getLocation(), diag::err_malformed_std_nothrow);
|
|
return nullptr;
|
|
}
|
|
|
|
ExprResult DR = S.BuildDeclRefExpr(VD, VD->getType(), VK_LValue, Loc);
|
|
if (DR.isInvalid())
|
|
return nullptr;
|
|
|
|
return DR.get();
|
|
}
|
|
|
|
// Find an appropriate delete for the promise.
|
|
static FunctionDecl *findDeleteForPromise(Sema &S, SourceLocation Loc,
|
|
QualType PromiseType) {
|
|
FunctionDecl *OperatorDelete = nullptr;
|
|
|
|
DeclarationName DeleteName =
|
|
S.Context.DeclarationNames.getCXXOperatorName(OO_Delete);
|
|
|
|
auto *PointeeRD = PromiseType->getAsCXXRecordDecl();
|
|
assert(PointeeRD && "PromiseType must be a CxxRecordDecl type");
|
|
|
|
// [dcl.fct.def.coroutine]p12
|
|
// The deallocation function's name is looked up by searching for it in the
|
|
// scope of the promise type. If nothing is found, a search is performed in
|
|
// the global scope.
|
|
if (S.FindDeallocationFunction(Loc, PointeeRD, DeleteName, OperatorDelete))
|
|
return nullptr;
|
|
|
|
// FIXME: We didn't implement following selection:
|
|
// [dcl.fct.def.coroutine]p12
|
|
// If both a usual deallocation function with only a pointer parameter and a
|
|
// usual deallocation function with both a pointer parameter and a size
|
|
// parameter are found, then the selected deallocation function shall be the
|
|
// one with two parameters. Otherwise, the selected deallocation function
|
|
// shall be the function with one parameter.
|
|
|
|
if (!OperatorDelete) {
|
|
// Look for a global declaration.
|
|
const bool CanProvideSize = S.isCompleteType(Loc, PromiseType);
|
|
const bool Overaligned = false;
|
|
OperatorDelete = S.FindUsualDeallocationFunction(Loc, CanProvideSize,
|
|
Overaligned, DeleteName);
|
|
}
|
|
S.MarkFunctionReferenced(Loc, OperatorDelete);
|
|
return OperatorDelete;
|
|
}
|
|
|
|
|
|
void Sema::CheckCompletedCoroutineBody(FunctionDecl *FD, Stmt *&Body) {
|
|
FunctionScopeInfo *Fn = getCurFunction();
|
|
assert(Fn && Fn->isCoroutine() && "not a coroutine");
|
|
if (!Body) {
|
|
assert(FD->isInvalidDecl() &&
|
|
"a null body is only allowed for invalid declarations");
|
|
return;
|
|
}
|
|
// We have a function that uses coroutine keywords, but we failed to build
|
|
// the promise type.
|
|
if (!Fn->CoroutinePromise)
|
|
return FD->setInvalidDecl();
|
|
|
|
if (isa<CoroutineBodyStmt>(Body)) {
|
|
// Nothing todo. the body is already a transformed coroutine body statement.
|
|
return;
|
|
}
|
|
|
|
// The always_inline attribute doesn't reliably apply to a coroutine,
|
|
// because the coroutine will be split into pieces and some pieces
|
|
// might be called indirectly, as in a virtual call. Even the ramp
|
|
// function cannot be inlined at -O0, due to pipeline ordering
|
|
// problems (see https://llvm.org/PR53413). Tell the user about it.
|
|
if (FD->hasAttr<AlwaysInlineAttr>())
|
|
Diag(FD->getLocation(), diag::warn_always_inline_coroutine);
|
|
|
|
// [stmt.return.coroutine]p1:
|
|
// A coroutine shall not enclose a return statement ([stmt.return]).
|
|
if (Fn->FirstReturnLoc.isValid()) {
|
|
assert(Fn->FirstCoroutineStmtLoc.isValid() &&
|
|
"first coroutine location not set");
|
|
Diag(Fn->FirstReturnLoc, diag::err_return_in_coroutine);
|
|
Diag(Fn->FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
|
|
<< Fn->getFirstCoroutineStmtKeyword();
|
|
}
|
|
CoroutineStmtBuilder Builder(*this, *FD, *Fn, Body);
|
|
if (Builder.isInvalid() || !Builder.buildStatements())
|
|
return FD->setInvalidDecl();
|
|
|
|
// Build body for the coroutine wrapper statement.
|
|
Body = CoroutineBodyStmt::Create(Context, Builder);
|
|
}
|
|
|
|
CoroutineStmtBuilder::CoroutineStmtBuilder(Sema &S, FunctionDecl &FD,
|
|
sema::FunctionScopeInfo &Fn,
|
|
Stmt *Body)
|
|
: S(S), FD(FD), Fn(Fn), Loc(FD.getLocation()),
|
|
IsPromiseDependentType(
|
|
!Fn.CoroutinePromise ||
|
|
Fn.CoroutinePromise->getType()->isDependentType()) {
|
|
this->Body = Body;
|
|
|
|
for (auto KV : Fn.CoroutineParameterMoves)
|
|
this->ParamMovesVector.push_back(KV.second);
|
|
this->ParamMoves = this->ParamMovesVector;
|
|
|
|
if (!IsPromiseDependentType) {
|
|
PromiseRecordDecl = Fn.CoroutinePromise->getType()->getAsCXXRecordDecl();
|
|
assert(PromiseRecordDecl && "Type should have already been checked");
|
|
}
|
|
this->IsValid = makePromiseStmt() && makeInitialAndFinalSuspend();
|
|
}
|
|
|
|
bool CoroutineStmtBuilder::buildStatements() {
|
|
assert(this->IsValid && "coroutine already invalid");
|
|
this->IsValid = makeReturnObject();
|
|
if (this->IsValid && !IsPromiseDependentType)
|
|
buildDependentStatements();
|
|
return this->IsValid;
|
|
}
|
|
|
|
bool CoroutineStmtBuilder::buildDependentStatements() {
|
|
assert(this->IsValid && "coroutine already invalid");
|
|
assert(!this->IsPromiseDependentType &&
|
|
"coroutine cannot have a dependent promise type");
|
|
this->IsValid = makeOnException() && makeOnFallthrough() &&
|
|
makeGroDeclAndReturnStmt() && makeReturnOnAllocFailure() &&
|
|
makeNewAndDeleteExpr();
|
|
return this->IsValid;
|
|
}
|
|
|
|
bool CoroutineStmtBuilder::makePromiseStmt() {
|
|
// Form a declaration statement for the promise declaration, so that AST
|
|
// visitors can more easily find it.
|
|
StmtResult PromiseStmt =
|
|
S.ActOnDeclStmt(S.ConvertDeclToDeclGroup(Fn.CoroutinePromise), Loc, Loc);
|
|
if (PromiseStmt.isInvalid())
|
|
return false;
|
|
|
|
this->Promise = PromiseStmt.get();
|
|
return true;
|
|
}
|
|
|
|
bool CoroutineStmtBuilder::makeInitialAndFinalSuspend() {
|
|
if (Fn.hasInvalidCoroutineSuspends())
|
|
return false;
|
|
this->InitialSuspend = cast<Expr>(Fn.CoroutineSuspends.first);
|
|
this->FinalSuspend = cast<Expr>(Fn.CoroutineSuspends.second);
|
|
return true;
|
|
}
|
|
|
|
static bool diagReturnOnAllocFailure(Sema &S, Expr *E,
|
|
CXXRecordDecl *PromiseRecordDecl,
|
|
FunctionScopeInfo &Fn) {
|
|
auto Loc = E->getExprLoc();
|
|
if (auto *DeclRef = dyn_cast_or_null<DeclRefExpr>(E)) {
|
|
auto *Decl = DeclRef->getDecl();
|
|
if (CXXMethodDecl *Method = dyn_cast_or_null<CXXMethodDecl>(Decl)) {
|
|
if (Method->isStatic())
|
|
return true;
|
|
else
|
|
Loc = Decl->getLocation();
|
|
}
|
|
}
|
|
|
|
S.Diag(
|
|
Loc,
|
|
diag::err_coroutine_promise_get_return_object_on_allocation_failure)
|
|
<< PromiseRecordDecl;
|
|
S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
|
|
<< Fn.getFirstCoroutineStmtKeyword();
|
|
return false;
|
|
}
|
|
|
|
bool CoroutineStmtBuilder::makeReturnOnAllocFailure() {
|
|
assert(!IsPromiseDependentType &&
|
|
"cannot make statement while the promise type is dependent");
|
|
|
|
// [dcl.fct.def.coroutine]p10
|
|
// If a search for the name get_return_object_on_allocation_failure in
|
|
// the scope of the promise type ([class.member.lookup]) finds any
|
|
// declarations, then the result of a call to an allocation function used to
|
|
// obtain storage for the coroutine state is assumed to return nullptr if it
|
|
// fails to obtain storage, ... If the allocation function returns nullptr,
|
|
// ... and the return value is obtained by a call to
|
|
// T::get_return_object_on_allocation_failure(), where T is the
|
|
// promise type.
|
|
DeclarationName DN =
|
|
S.PP.getIdentifierInfo("get_return_object_on_allocation_failure");
|
|
LookupResult Found(S, DN, Loc, Sema::LookupMemberName);
|
|
if (!S.LookupQualifiedName(Found, PromiseRecordDecl))
|
|
return true;
|
|
|
|
CXXScopeSpec SS;
|
|
ExprResult DeclNameExpr =
|
|
S.BuildDeclarationNameExpr(SS, Found, /*NeedsADL=*/false);
|
|
if (DeclNameExpr.isInvalid())
|
|
return false;
|
|
|
|
if (!diagReturnOnAllocFailure(S, DeclNameExpr.get(), PromiseRecordDecl, Fn))
|
|
return false;
|
|
|
|
ExprResult ReturnObjectOnAllocationFailure =
|
|
S.BuildCallExpr(nullptr, DeclNameExpr.get(), Loc, {}, Loc);
|
|
if (ReturnObjectOnAllocationFailure.isInvalid())
|
|
return false;
|
|
|
|
StmtResult ReturnStmt =
|
|
S.BuildReturnStmt(Loc, ReturnObjectOnAllocationFailure.get());
|
|
if (ReturnStmt.isInvalid()) {
|
|
S.Diag(Found.getFoundDecl()->getLocation(), diag::note_member_declared_here)
|
|
<< DN;
|
|
S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
|
|
<< Fn.getFirstCoroutineStmtKeyword();
|
|
return false;
|
|
}
|
|
|
|
this->ReturnStmtOnAllocFailure = ReturnStmt.get();
|
|
return true;
|
|
}
|
|
|
|
bool CoroutineStmtBuilder::makeNewAndDeleteExpr() {
|
|
// Form and check allocation and deallocation calls.
|
|
assert(!IsPromiseDependentType &&
|
|
"cannot make statement while the promise type is dependent");
|
|
QualType PromiseType = Fn.CoroutinePromise->getType();
|
|
|
|
if (S.RequireCompleteType(Loc, PromiseType, diag::err_incomplete_type))
|
|
return false;
|
|
|
|
const bool RequiresNoThrowAlloc = ReturnStmtOnAllocFailure != nullptr;
|
|
|
|
// According to [dcl.fct.def.coroutine]p9, Lookup allocation functions using a
|
|
// parameter list composed of the requested size of the coroutine state being
|
|
// allocated, followed by the coroutine function's arguments. If a matching
|
|
// allocation function exists, use it. Otherwise, use an allocation function
|
|
// that just takes the requested size.
|
|
|
|
FunctionDecl *OperatorNew = nullptr;
|
|
FunctionDecl *OperatorDelete = nullptr;
|
|
FunctionDecl *UnusedResult = nullptr;
|
|
bool PassAlignment = false;
|
|
SmallVector<Expr *, 1> PlacementArgs;
|
|
|
|
// [dcl.fct.def.coroutine]p9
|
|
// An implementation may need to allocate additional storage for a
|
|
// coroutine.
|
|
// This storage is known as the coroutine state and is obtained by calling a
|
|
// non-array allocation function ([basic.stc.dynamic.allocation]). The
|
|
// allocation function's name is looked up by searching for it in the scope of
|
|
// the promise type.
|
|
// - If any declarations are found, overload resolution is performed on a
|
|
// function call created by assembling an argument list. The first argument is
|
|
// the amount of space requested, and has type std::size_t. The
|
|
// lvalues p1 ... pn are the succeeding arguments.
|
|
//
|
|
// ...where "p1 ... pn" are defined earlier as:
|
|
//
|
|
// [dcl.fct.def.coroutine]p3
|
|
// The promise type of a coroutine is `std::coroutine_traits<R, P1, ...,
|
|
// Pn>`
|
|
// , where R is the return type of the function, and `P1, ..., Pn` are the
|
|
// sequence of types of the non-object function parameters, preceded by the
|
|
// type of the object parameter ([dcl.fct]) if the coroutine is a non-static
|
|
// member function. [dcl.fct.def.coroutine]p4 In the following, p_i is an
|
|
// lvalue of type P_i, where p1 denotes the object parameter and p_i+1 denotes
|
|
// the i-th non-object function parameter for a non-static member function,
|
|
// and p_i denotes the i-th function parameter otherwise. For a non-static
|
|
// member function, q_1 is an lvalue that denotes *this; any other q_i is an
|
|
// lvalue that denotes the parameter copy corresponding to p_i.
|
|
if (auto *MD = dyn_cast<CXXMethodDecl>(&FD)) {
|
|
if (MD->isInstance() && !isLambdaCallOperator(MD)) {
|
|
ExprResult ThisExpr = S.ActOnCXXThis(Loc);
|
|
if (ThisExpr.isInvalid())
|
|
return false;
|
|
ThisExpr = S.CreateBuiltinUnaryOp(Loc, UO_Deref, ThisExpr.get());
|
|
if (ThisExpr.isInvalid())
|
|
return false;
|
|
PlacementArgs.push_back(ThisExpr.get());
|
|
}
|
|
}
|
|
for (auto *PD : FD.parameters()) {
|
|
if (PD->getType()->isDependentType())
|
|
continue;
|
|
|
|
// Build a reference to the parameter.
|
|
auto PDLoc = PD->getLocation();
|
|
ExprResult PDRefExpr =
|
|
S.BuildDeclRefExpr(PD, PD->getOriginalType().getNonReferenceType(),
|
|
ExprValueKind::VK_LValue, PDLoc);
|
|
if (PDRefExpr.isInvalid())
|
|
return false;
|
|
|
|
PlacementArgs.push_back(PDRefExpr.get());
|
|
}
|
|
S.FindAllocationFunctions(Loc, SourceRange(), /*NewScope*/ Sema::AFS_Class,
|
|
/*DeleteScope*/ Sema::AFS_Both, PromiseType,
|
|
/*isArray*/ false, PassAlignment, PlacementArgs,
|
|
OperatorNew, UnusedResult, /*Diagnose*/ false);
|
|
|
|
// [dcl.fct.def.coroutine]p9
|
|
// If no viable function is found ([over.match.viable]), overload resolution
|
|
// is performed again on a function call created by passing just the amount of
|
|
// space required as an argument of type std::size_t.
|
|
if (!OperatorNew && !PlacementArgs.empty()) {
|
|
PlacementArgs.clear();
|
|
S.FindAllocationFunctions(Loc, SourceRange(), /*NewScope*/ Sema::AFS_Class,
|
|
/*DeleteScope*/ Sema::AFS_Both, PromiseType,
|
|
/*isArray*/ false, PassAlignment, PlacementArgs,
|
|
OperatorNew, UnusedResult, /*Diagnose*/ false);
|
|
}
|
|
|
|
// [dcl.fct.def.coroutine]p9
|
|
// The allocation function's name is looked up by searching for it in the
|
|
// scope of the promise type.
|
|
// - If any declarations are found, ...
|
|
// - Otherwise, a search is performed in the global scope.
|
|
if (!OperatorNew) {
|
|
S.FindAllocationFunctions(Loc, SourceRange(), /*NewScope*/ Sema::AFS_Global,
|
|
/*DeleteScope*/ Sema::AFS_Both, PromiseType,
|
|
/*isArray*/ false, PassAlignment, PlacementArgs,
|
|
OperatorNew, UnusedResult);
|
|
}
|
|
|
|
bool IsGlobalOverload =
|
|
OperatorNew && !isa<CXXRecordDecl>(OperatorNew->getDeclContext());
|
|
// If we didn't find a class-local new declaration and non-throwing new
|
|
// was is required then we need to lookup the non-throwing global operator
|
|
// instead.
|
|
if (RequiresNoThrowAlloc && (!OperatorNew || IsGlobalOverload)) {
|
|
auto *StdNoThrow = buildStdNoThrowDeclRef(S, Loc);
|
|
if (!StdNoThrow)
|
|
return false;
|
|
PlacementArgs = {StdNoThrow};
|
|
OperatorNew = nullptr;
|
|
S.FindAllocationFunctions(Loc, SourceRange(), /*NewScope*/ Sema::AFS_Both,
|
|
/*DeleteScope*/ Sema::AFS_Both, PromiseType,
|
|
/*isArray*/ false, PassAlignment, PlacementArgs,
|
|
OperatorNew, UnusedResult);
|
|
}
|
|
|
|
if (!OperatorNew)
|
|
return false;
|
|
|
|
if (RequiresNoThrowAlloc) {
|
|
const auto *FT = OperatorNew->getType()->castAs<FunctionProtoType>();
|
|
if (!FT->isNothrow(/*ResultIfDependent*/ false)) {
|
|
S.Diag(OperatorNew->getLocation(),
|
|
diag::err_coroutine_promise_new_requires_nothrow)
|
|
<< OperatorNew;
|
|
S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required)
|
|
<< OperatorNew;
|
|
return false;
|
|
}
|
|
}
|
|
|
|
if ((OperatorDelete = findDeleteForPromise(S, Loc, PromiseType)) == nullptr) {
|
|
// FIXME: We should add an error here. According to:
|
|
// [dcl.fct.def.coroutine]p12
|
|
// If no usual deallocation function is found, the program is ill-formed.
|
|
return false;
|
|
}
|
|
|
|
Expr *FramePtr =
|
|
S.BuildBuiltinCallExpr(Loc, Builtin::BI__builtin_coro_frame, {});
|
|
|
|
Expr *FrameSize =
|
|
S.BuildBuiltinCallExpr(Loc, Builtin::BI__builtin_coro_size, {});
|
|
|
|
// Make new call.
|
|
|
|
ExprResult NewRef =
|
|
S.BuildDeclRefExpr(OperatorNew, OperatorNew->getType(), VK_LValue, Loc);
|
|
if (NewRef.isInvalid())
|
|
return false;
|
|
|
|
SmallVector<Expr *, 2> NewArgs(1, FrameSize);
|
|
for (auto Arg : PlacementArgs)
|
|
NewArgs.push_back(Arg);
|
|
|
|
ExprResult NewExpr =
|
|
S.BuildCallExpr(S.getCurScope(), NewRef.get(), Loc, NewArgs, Loc);
|
|
NewExpr = S.ActOnFinishFullExpr(NewExpr.get(), /*DiscardedValue*/ false);
|
|
if (NewExpr.isInvalid())
|
|
return false;
|
|
|
|
// Make delete call.
|
|
|
|
QualType OpDeleteQualType = OperatorDelete->getType();
|
|
|
|
ExprResult DeleteRef =
|
|
S.BuildDeclRefExpr(OperatorDelete, OpDeleteQualType, VK_LValue, Loc);
|
|
if (DeleteRef.isInvalid())
|
|
return false;
|
|
|
|
Expr *CoroFree =
|
|
S.BuildBuiltinCallExpr(Loc, Builtin::BI__builtin_coro_free, {FramePtr});
|
|
|
|
SmallVector<Expr *, 2> DeleteArgs{CoroFree};
|
|
|
|
// [dcl.fct.def.coroutine]p12
|
|
// The selected deallocation function shall be called with the address of
|
|
// the block of storage to be reclaimed as its first argument. If a
|
|
// deallocation function with a parameter of type std::size_t is
|
|
// used, the size of the block is passed as the corresponding argument.
|
|
const auto *OpDeleteType =
|
|
OpDeleteQualType.getTypePtr()->castAs<FunctionProtoType>();
|
|
if (OpDeleteType->getNumParams() > 1)
|
|
DeleteArgs.push_back(FrameSize);
|
|
|
|
ExprResult DeleteExpr =
|
|
S.BuildCallExpr(S.getCurScope(), DeleteRef.get(), Loc, DeleteArgs, Loc);
|
|
DeleteExpr =
|
|
S.ActOnFinishFullExpr(DeleteExpr.get(), /*DiscardedValue*/ false);
|
|
if (DeleteExpr.isInvalid())
|
|
return false;
|
|
|
|
this->Allocate = NewExpr.get();
|
|
this->Deallocate = DeleteExpr.get();
|
|
|
|
return true;
|
|
}
|
|
|
|
bool CoroutineStmtBuilder::makeOnFallthrough() {
|
|
assert(!IsPromiseDependentType &&
|
|
"cannot make statement while the promise type is dependent");
|
|
|
|
// [dcl.fct.def.coroutine]/p6
|
|
// If searches for the names return_void and return_value in the scope of
|
|
// the promise type each find any declarations, the program is ill-formed.
|
|
// [Note 1: If return_void is found, flowing off the end of a coroutine is
|
|
// equivalent to a co_return with no operand. Otherwise, flowing off the end
|
|
// of a coroutine results in undefined behavior ([stmt.return.coroutine]). —
|
|
// end note]
|
|
bool HasRVoid, HasRValue;
|
|
LookupResult LRVoid =
|
|
lookupMember(S, "return_void", PromiseRecordDecl, Loc, HasRVoid);
|
|
LookupResult LRValue =
|
|
lookupMember(S, "return_value", PromiseRecordDecl, Loc, HasRValue);
|
|
|
|
StmtResult Fallthrough;
|
|
if (HasRVoid && HasRValue) {
|
|
// FIXME Improve this diagnostic
|
|
S.Diag(FD.getLocation(),
|
|
diag::err_coroutine_promise_incompatible_return_functions)
|
|
<< PromiseRecordDecl;
|
|
S.Diag(LRVoid.getRepresentativeDecl()->getLocation(),
|
|
diag::note_member_first_declared_here)
|
|
<< LRVoid.getLookupName();
|
|
S.Diag(LRValue.getRepresentativeDecl()->getLocation(),
|
|
diag::note_member_first_declared_here)
|
|
<< LRValue.getLookupName();
|
|
return false;
|
|
} else if (!HasRVoid && !HasRValue) {
|
|
// We need to set 'Fallthrough'. Otherwise the other analysis part might
|
|
// think the coroutine has defined a return_value method. So it might emit
|
|
// **false** positive warning. e.g.,
|
|
//
|
|
// promise_without_return_func foo() {
|
|
// co_await something();
|
|
// }
|
|
//
|
|
// Then AnalysisBasedWarning would emit a warning about `foo()` lacking a
|
|
// co_return statements, which isn't correct.
|
|
Fallthrough = S.ActOnNullStmt(PromiseRecordDecl->getLocation());
|
|
if (Fallthrough.isInvalid())
|
|
return false;
|
|
} else if (HasRVoid) {
|
|
Fallthrough = S.BuildCoreturnStmt(FD.getLocation(), nullptr,
|
|
/*IsImplicit*/false);
|
|
Fallthrough = S.ActOnFinishFullStmt(Fallthrough.get());
|
|
if (Fallthrough.isInvalid())
|
|
return false;
|
|
}
|
|
|
|
this->OnFallthrough = Fallthrough.get();
|
|
return true;
|
|
}
|
|
|
|
bool CoroutineStmtBuilder::makeOnException() {
|
|
// Try to form 'p.unhandled_exception();'
|
|
assert(!IsPromiseDependentType &&
|
|
"cannot make statement while the promise type is dependent");
|
|
|
|
const bool RequireUnhandledException = S.getLangOpts().CXXExceptions;
|
|
|
|
if (!lookupMember(S, "unhandled_exception", PromiseRecordDecl, Loc)) {
|
|
auto DiagID =
|
|
RequireUnhandledException
|
|
? diag::err_coroutine_promise_unhandled_exception_required
|
|
: diag::
|
|
warn_coroutine_promise_unhandled_exception_required_with_exceptions;
|
|
S.Diag(Loc, DiagID) << PromiseRecordDecl;
|
|
S.Diag(PromiseRecordDecl->getLocation(), diag::note_defined_here)
|
|
<< PromiseRecordDecl;
|
|
return !RequireUnhandledException;
|
|
}
|
|
|
|
// If exceptions are disabled, don't try to build OnException.
|
|
if (!S.getLangOpts().CXXExceptions)
|
|
return true;
|
|
|
|
ExprResult UnhandledException = buildPromiseCall(S, Fn.CoroutinePromise, Loc,
|
|
"unhandled_exception", None);
|
|
UnhandledException = S.ActOnFinishFullExpr(UnhandledException.get(), Loc,
|
|
/*DiscardedValue*/ false);
|
|
if (UnhandledException.isInvalid())
|
|
return false;
|
|
|
|
// Since the body of the coroutine will be wrapped in try-catch, it will
|
|
// be incompatible 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;
|
|
}
|
|
|
|
bool CoroutineStmtBuilder::makeReturnObject() {
|
|
// [dcl.fct.def.coroutine]p7
|
|
// The expression promise.get_return_object() is used to initialize the
|
|
// returned reference or prvalue result object of a call to a coroutine.
|
|
ExprResult ReturnObject =
|
|
buildPromiseCall(S, Fn.CoroutinePromise, Loc, "get_return_object", None);
|
|
if (ReturnObject.isInvalid())
|
|
return false;
|
|
|
|
this->ReturnValue = ReturnObject.get();
|
|
return true;
|
|
}
|
|
|
|
static void noteMemberDeclaredHere(Sema &S, Expr *E, FunctionScopeInfo &Fn) {
|
|
if (auto *MbrRef = dyn_cast<CXXMemberCallExpr>(E)) {
|
|
auto *MethodDecl = MbrRef->getMethodDecl();
|
|
S.Diag(MethodDecl->getLocation(), diag::note_member_declared_here)
|
|
<< MethodDecl;
|
|
}
|
|
S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
|
|
<< Fn.getFirstCoroutineStmtKeyword();
|
|
}
|
|
|
|
bool CoroutineStmtBuilder::makeGroDeclAndReturnStmt() {
|
|
assert(!IsPromiseDependentType &&
|
|
"cannot make statement while the promise type is dependent");
|
|
assert(this->ReturnValue && "ReturnValue must be already formed");
|
|
|
|
QualType const GroType = this->ReturnValue->getType();
|
|
assert(!GroType->isDependentType() &&
|
|
"get_return_object type must no longer be dependent");
|
|
|
|
QualType const FnRetType = FD.getReturnType();
|
|
assert(!FnRetType->isDependentType() &&
|
|
"get_return_object type must no longer be dependent");
|
|
|
|
if (FnRetType->isVoidType()) {
|
|
ExprResult Res =
|
|
S.ActOnFinishFullExpr(this->ReturnValue, Loc, /*DiscardedValue*/ false);
|
|
if (Res.isInvalid())
|
|
return false;
|
|
|
|
this->ResultDecl = Res.get();
|
|
return true;
|
|
}
|
|
|
|
if (GroType->isVoidType()) {
|
|
// Trigger a nice error message.
|
|
InitializedEntity Entity =
|
|
InitializedEntity::InitializeResult(Loc, FnRetType);
|
|
S.PerformCopyInitialization(Entity, SourceLocation(), ReturnValue);
|
|
noteMemberDeclaredHere(S, ReturnValue, Fn);
|
|
return false;
|
|
}
|
|
|
|
auto *GroDecl = VarDecl::Create(
|
|
S.Context, &FD, FD.getLocation(), FD.getLocation(),
|
|
&S.PP.getIdentifierTable().get("__coro_gro"), GroType,
|
|
S.Context.getTrivialTypeSourceInfo(GroType, Loc), SC_None);
|
|
GroDecl->setImplicit();
|
|
|
|
S.CheckVariableDeclarationType(GroDecl);
|
|
if (GroDecl->isInvalidDecl())
|
|
return false;
|
|
|
|
InitializedEntity Entity = InitializedEntity::InitializeVariable(GroDecl);
|
|
ExprResult Res =
|
|
S.PerformCopyInitialization(Entity, SourceLocation(), ReturnValue);
|
|
if (Res.isInvalid())
|
|
return false;
|
|
|
|
Res = S.ActOnFinishFullExpr(Res.get(), /*DiscardedValue*/ false);
|
|
if (Res.isInvalid())
|
|
return false;
|
|
|
|
S.AddInitializerToDecl(GroDecl, Res.get(),
|
|
/*DirectInit=*/false);
|
|
|
|
S.FinalizeDeclaration(GroDecl);
|
|
|
|
// Form a declaration statement for the return declaration, so that AST
|
|
// visitors can more easily find it.
|
|
StmtResult GroDeclStmt =
|
|
S.ActOnDeclStmt(S.ConvertDeclToDeclGroup(GroDecl), Loc, Loc);
|
|
if (GroDeclStmt.isInvalid())
|
|
return false;
|
|
|
|
this->ResultDecl = GroDeclStmt.get();
|
|
|
|
ExprResult declRef = S.BuildDeclRefExpr(GroDecl, GroType, VK_LValue, Loc);
|
|
if (declRef.isInvalid())
|
|
return false;
|
|
|
|
StmtResult ReturnStmt = S.BuildReturnStmt(Loc, declRef.get());
|
|
if (ReturnStmt.isInvalid()) {
|
|
noteMemberDeclaredHere(S, ReturnValue, Fn);
|
|
return false;
|
|
}
|
|
if (cast<clang::ReturnStmt>(ReturnStmt.get())->getNRVOCandidate() == GroDecl)
|
|
GroDecl->setNRVOVariable(true);
|
|
|
|
this->ReturnStmt = ReturnStmt.get();
|
|
return true;
|
|
}
|
|
|
|
// Create a static_cast\<T&&>(expr).
|
|
static Expr *castForMoving(Sema &S, Expr *E, QualType T = QualType()) {
|
|
if (T.isNull())
|
|
T = E->getType();
|
|
QualType TargetType = S.BuildReferenceType(
|
|
T, /*SpelledAsLValue*/ false, SourceLocation(), DeclarationName());
|
|
SourceLocation ExprLoc = E->getBeginLoc();
|
|
TypeSourceInfo *TargetLoc =
|
|
S.Context.getTrivialTypeSourceInfo(TargetType, ExprLoc);
|
|
|
|
return S
|
|
.BuildCXXNamedCast(ExprLoc, tok::kw_static_cast, TargetLoc, E,
|
|
SourceRange(ExprLoc, ExprLoc), E->getSourceRange())
|
|
.get();
|
|
}
|
|
|
|
/// Build a variable declaration for move parameter.
|
|
static VarDecl *buildVarDecl(Sema &S, SourceLocation Loc, QualType Type,
|
|
IdentifierInfo *II) {
|
|
TypeSourceInfo *TInfo = S.Context.getTrivialTypeSourceInfo(Type, Loc);
|
|
VarDecl *Decl = VarDecl::Create(S.Context, S.CurContext, Loc, Loc, II, Type,
|
|
TInfo, SC_None);
|
|
Decl->setImplicit();
|
|
return Decl;
|
|
}
|
|
|
|
// Build statements that move coroutine function parameters to the coroutine
|
|
// frame, and store them on the function scope info.
|
|
bool Sema::buildCoroutineParameterMoves(SourceLocation Loc) {
|
|
assert(isa<FunctionDecl>(CurContext) && "not in a function scope");
|
|
auto *FD = cast<FunctionDecl>(CurContext);
|
|
|
|
auto *ScopeInfo = getCurFunction();
|
|
if (!ScopeInfo->CoroutineParameterMoves.empty())
|
|
return false;
|
|
|
|
// [dcl.fct.def.coroutine]p13
|
|
// When a coroutine is invoked, after initializing its parameters
|
|
// ([expr.call]), a copy is created for each coroutine parameter. For a
|
|
// parameter of type cv T, the copy is a variable of type cv T with
|
|
// automatic storage duration that is direct-initialized from an xvalue of
|
|
// type T referring to the parameter.
|
|
for (auto *PD : FD->parameters()) {
|
|
if (PD->getType()->isDependentType())
|
|
continue;
|
|
|
|
ExprResult PDRefExpr =
|
|
BuildDeclRefExpr(PD, PD->getType().getNonReferenceType(),
|
|
ExprValueKind::VK_LValue, Loc); // FIXME: scope?
|
|
if (PDRefExpr.isInvalid())
|
|
return false;
|
|
|
|
Expr *CExpr = nullptr;
|
|
if (PD->getType()->getAsCXXRecordDecl() ||
|
|
PD->getType()->isRValueReferenceType())
|
|
CExpr = castForMoving(*this, PDRefExpr.get());
|
|
else
|
|
CExpr = PDRefExpr.get();
|
|
// [dcl.fct.def.coroutine]p13
|
|
// The initialization and destruction of each parameter copy occurs in the
|
|
// context of the called coroutine.
|
|
auto D = buildVarDecl(*this, Loc, PD->getType(), PD->getIdentifier());
|
|
AddInitializerToDecl(D, CExpr, /*DirectInit=*/true);
|
|
|
|
// Convert decl to a statement.
|
|
StmtResult Stmt = ActOnDeclStmt(ConvertDeclToDeclGroup(D), Loc, Loc);
|
|
if (Stmt.isInvalid())
|
|
return false;
|
|
|
|
ScopeInfo->CoroutineParameterMoves.insert(std::make_pair(PD, Stmt.get()));
|
|
}
|
|
return true;
|
|
}
|
|
|
|
StmtResult Sema::BuildCoroutineBodyStmt(CoroutineBodyStmt::CtorArgs Args) {
|
|
CoroutineBodyStmt *Res = CoroutineBodyStmt::Create(Context, Args);
|
|
if (!Res)
|
|
return StmtError();
|
|
return Res;
|
|
}
|
|
|
|
ClassTemplateDecl *Sema::lookupCoroutineTraits(SourceLocation KwLoc,
|
|
SourceLocation FuncLoc,
|
|
NamespaceDecl *&Namespace) {
|
|
if (!StdCoroutineTraitsCache) {
|
|
// Because coroutines moved from std::experimental in the TS to std in
|
|
// C++20, we look in both places to give users time to transition their
|
|
// TS-specific code to C++20. Diagnostics are given when the TS usage is
|
|
// discovered.
|
|
// TODO: Become stricter when <experimental/coroutine> is removed.
|
|
|
|
auto const &TraitIdent = PP.getIdentifierTable().get("coroutine_traits");
|
|
|
|
NamespaceDecl *StdSpace = getStdNamespace();
|
|
LookupResult ResStd(*this, &TraitIdent, FuncLoc, LookupOrdinaryName);
|
|
bool InStd = StdSpace && LookupQualifiedName(ResStd, StdSpace);
|
|
|
|
NamespaceDecl *ExpSpace = lookupStdExperimentalNamespace();
|
|
LookupResult ResExp(*this, &TraitIdent, FuncLoc, LookupOrdinaryName);
|
|
bool InExp = ExpSpace && LookupQualifiedName(ResExp, ExpSpace);
|
|
|
|
if (!InStd && !InExp) {
|
|
// The goggles, they found nothing!
|
|
Diag(KwLoc, diag::err_implied_coroutine_type_not_found)
|
|
<< "std::coroutine_traits";
|
|
return nullptr;
|
|
}
|
|
|
|
// Prefer ::std to std::experimental.
|
|
auto &Result = InStd ? ResStd : ResExp;
|
|
CoroTraitsNamespaceCache = InStd ? StdSpace : ExpSpace;
|
|
|
|
// coroutine_traits is required to be a class template.
|
|
StdCoroutineTraitsCache = Result.getAsSingle<ClassTemplateDecl>();
|
|
if (!StdCoroutineTraitsCache) {
|
|
Result.suppressDiagnostics();
|
|
NamedDecl *Found = *Result.begin();
|
|
Diag(Found->getLocation(), diag::err_malformed_std_coroutine_traits);
|
|
return nullptr;
|
|
}
|
|
|
|
if (InExp) {
|
|
// Found in std::experimental
|
|
Diag(KwLoc, diag::warn_deprecated_coroutine_namespace)
|
|
<< "coroutine_traits";
|
|
ResExp.suppressDiagnostics();
|
|
auto *Found = *ResExp.begin();
|
|
Diag(Found->getLocation(), diag::note_entity_declared_at) << Found;
|
|
|
|
if (InStd &&
|
|
StdCoroutineTraitsCache != ResExp.getAsSingle<ClassTemplateDecl>()) {
|
|
// Also found something different in std
|
|
Diag(KwLoc,
|
|
diag::err_mixed_use_std_and_experimental_namespace_for_coroutine);
|
|
Diag(StdCoroutineTraitsCache->getLocation(),
|
|
diag::note_entity_declared_at)
|
|
<< StdCoroutineTraitsCache;
|
|
|
|
return nullptr;
|
|
}
|
|
}
|
|
}
|
|
Namespace = CoroTraitsNamespaceCache;
|
|
return StdCoroutineTraitsCache;
|
|
}
|