std::vector<CallExpr *> Utils::callListForChain(CallExpr *lastCallExpr)
{
if (!lastCallExpr)
return {};
const bool isOperator = isa<CXXOperatorCallExpr>(lastCallExpr);
vector<CallExpr *> callexprs = { lastCallExpr };
Stmt *s = lastCallExpr;
do {
const int childCount = std::distance(s->child_begin(), s->child_end());
if (isOperator && childCount > 1) {
// for operator case, the chained call childs are in the second child
s = *(++s->child_begin());
} else {
s = childCount > 0 ? *s->child_begin() : nullptr;
}
if (s) {
CallExpr *callExpr = dyn_cast<CallExpr>(s);
if (callExpr && callExpr->getCalleeDecl()) {
callexprs.push_back(callExpr);
} else if (MemberExpr *memberExpr = dyn_cast<MemberExpr>(s)) {
if (isa<FieldDecl>(memberExpr->getMemberDecl()))
break; // accessing a public member via . or -> breaks the chain
}
}
} while (s);
return callexprs;
}
/// Build calls to await_ready, await_suspend, and await_resume for a 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 invalid until we see otherwise.
ReadySuspendResumeResult Calls = {{}, Operand, /*IsInvalid=*/true};
ExprResult CoroHandleRes = buildCoroutineHandle(S, CoroPromise->getType(), Loc);
if (CoroHandleRes.isInvalid())
return Calls;
Expr *CoroHandle = CoroHandleRes.get();
const StringRef Funcs[] = {"await_ready", "await_suspend", "await_resume"};
MultiExprArg Args[] = {None, CoroHandle, None};
for (size_t I = 0, N = llvm::array_lengthof(Funcs); I != N; ++I) {
ExprResult Result = buildMemberCall(S, Operand, Loc, Funcs[I], Args[I]);
if (Result.isInvalid())
return Calls;
Calls.Results[I] = Result.get();
}
// Assume the calls are valid; all further checking should make them invalid.
Calls.IsInvalid = false;
using ACT = ReadySuspendResumeResult::AwaitCallType;
CallExpr *AwaitReady = cast<CallExpr>(Calls.Results[ACT::ACT_Ready]);
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()->getLocStart(),
diag::note_await_ready_no_bool_conversion);
S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required)
<< AwaitReady->getDirectCallee() << E->getSourceRange();
Calls.IsInvalid = true;
}
Calls.Results[ACT::ACT_Ready] = Conv.get();
}
CallExpr *AwaitSuspend = cast<CallExpr>(Calls.Results[ACT::ACT_Suspend]);
if (!AwaitSuspend->getType()->isDependentType()) {
// [expr.await]p3 [...]
// - await-suspend is the expression e.await_suspend(h), which shall be
// a prvalue of type void or bool.
QualType RetType = AwaitSuspend->getType();
if (RetType != S.Context.BoolTy && RetType != S.Context.VoidTy) {
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;
}
}
return Calls;
}
