/// Emit a store of a native error to the foreign-error slot.
static void emitStoreToForeignErrorSlot(SILGenFunction &gen,
SILLocation loc,
SILValue foreignErrorSlot,
const BridgedErrorSource &errorSrc) {
ASTContext &ctx = gen.getASTContext();
// The foreign error slot has type SomePointer<SomeErrorProtocol?>,
// or possibly an optional thereof.
// If the pointer itself is optional, we need to branch based on
// whether it's really there.
// FIXME: this code is written expecting pointer types to actually
// be optional, as opposed to simply having a null inhabitant.
OptionalTypeKind errorPtrOptKind;
if (SILType errorPtrObjectTy =
foreignErrorSlot->getType()
.getAnyOptionalObjectType(gen.SGM.M, errorPtrOptKind)) {
SILBasicBlock *contBB = gen.createBasicBlock();
SILBasicBlock *noSlotBB = gen.createBasicBlock();
SILBasicBlock *hasSlotBB = gen.createBasicBlock();
gen.B.createSwitchEnum(loc, foreignErrorSlot, nullptr,
{ { ctx.getOptionalSomeDecl(errorPtrOptKind), hasSlotBB },
{ ctx.getOptionalNoneDecl(errorPtrOptKind), noSlotBB } });
// If we have the slot, emit a store to it.
gen.B.emitBlock(hasSlotBB);
SILValue slot = hasSlotBB->createBBArg(errorPtrObjectTy);
emitStoreToForeignErrorSlot(gen, loc, slot, errorSrc);
gen.B.createBranch(loc, contBB);
// Otherwise, just release the error.
gen.B.emitBlock(noSlotBB);
errorSrc.emitRelease(gen, loc);
gen.B.createBranch(loc, contBB);
// Continue.
gen.B.emitBlock(contBB);
return;
}
// Okay, break down the components of SomePointer<SomeErrorProtocol?>.
// TODO: this should really be an unlowered AST type?
CanType bridgedErrorPtrType =
foreignErrorSlot->getType().getSwiftRValueType();
PointerTypeKind ptrKind;
CanType bridgedErrorProtocol =
CanType(bridgedErrorPtrType->getAnyPointerElementType(ptrKind));
FullExpr scope(gen.Cleanups, CleanupLocation::get(loc));
WritebackScope writebacks(gen);
// Convert the error to a bridged form.
SILValue bridgedError = errorSrc.emitBridged(gen, loc, bridgedErrorProtocol);
// Store to the "pointee" property.
// If we can't find it, diagnose and then just don't store anything.
VarDecl *pointeeProperty = ctx.getPointerPointeePropertyDecl(ptrKind);
if (!pointeeProperty) {
gen.SGM.diagnose(loc, diag::could_not_find_pointer_pointee_property,
bridgedErrorPtrType);
return;
}
// Otherwise, do a normal assignment.
LValue lvalue =
gen.emitPropertyLValue(loc, ManagedValue::forUnmanaged(foreignErrorSlot),
bridgedErrorPtrType, pointeeProperty,
AccessKind::Write,
AccessSemantics::Ordinary);
RValue rvalue(gen, loc, bridgedErrorProtocol,
gen.emitManagedRValueWithCleanup(bridgedError));
gen.emitAssignToLValue(loc, std::move(rvalue), std::move(lvalue));
}
