/// 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;
}
virtual void expandGraph(ExplodedNodeSet &Dst, ExplodedNode *Pred) {
ProgramStateRef state = getReplayWithoutInliningState(Pred, CE);
// First, try to inline the call.
if (state == 0 && Eng.InlineCall(Dst, CE, Pred))
return;
// First handle the return value.
StmtNodeBuilder Bldr(Pred, Dst, *Eng.currentBuilderContext);
// Get the callee.
const Expr *Callee = CE->getCallee()->IgnoreParens();
if (state == 0)
state = Pred->getState();
SVal L = state->getSVal(Callee, Pred->getLocationContext());
// Figure out the result type. We do this dance to handle references.
QualType ResultTy;
if (const FunctionDecl *FD = L.getAsFunctionDecl())
ResultTy = FD->getResultType();
else
ResultTy = CE->getType();
if (CE->isLValue())
ResultTy = Eng.getContext().getPointerType(ResultTy);
// Conjure a symbol value to use as the result.
SValBuilder &SVB = Eng.getSValBuilder();
unsigned Count = Eng.currentBuilderContext->getCurrentBlockCount();
const LocationContext *LCtx = Pred->getLocationContext();
SVal RetVal = SVB.getConjuredSymbolVal(0, CE, LCtx, ResultTy, Count);
// Generate a new state with the return value set.
state = state->BindExpr(CE, LCtx, RetVal);
// Invalidate the arguments.
state = Eng.invalidateArguments(state, CallOrObjCMessage(CE, state, LCtx),
LCtx);
// And make the result node.
Bldr.generateNode(CE, Pred, state);
}