SILValue SILGenFunction::emitGlobalFunctionRef(SILLocation loc,
SILDeclRef constant,
SILConstantInfo constantInfo) {
assert(constantInfo == getConstantInfo(constant));
// Builtins must be fully applied at the point of reference.
if (constant.hasDecl() &&
isa<BuiltinUnit>(constant.getDecl()->getDeclContext())) {
SGM.diagnose(loc.getSourceLoc(), diag::not_implemented,
"delayed application of builtin");
return SILUndef::get(constantInfo.getSILType(), SGM.M);
}
// If the constant is a thunk we haven't emitted yet, emit it.
if (!SGM.hasFunction(constant)) {
if (constant.isCurried) {
SGM.emitCurryThunk(constant);
} else if (constant.isForeignToNativeThunk()) {
SGM.emitForeignToNativeThunk(constant);
} else if (constant.isNativeToForeignThunk()) {
SGM.emitNativeToForeignThunk(constant);
} else if (constant.kind == SILDeclRef::Kind::EnumElement) {
SGM.emitEnumConstructor(cast<EnumElementDecl>(constant.getDecl()));
}
}
auto f = SGM.getFunction(constant, NotForDefinition);
assert(f->getLoweredFunctionType() == constantInfo.SILFnType);
return B.createFunctionRef(loc, f);
}
/// Given that this is an 'Unknown' value, emit diagnostic notes providing
/// context about what the problem is.
void SymbolicValue::emitUnknownDiagnosticNotes(SILLocation fallbackLoc) {
auto badInst = dyn_cast<SILInstruction>(getUnknownNode());
if (!badInst)
return;
bool emittedFirstNote = emitNoteDiagnostic(badInst, getUnknownReason(),
fallbackLoc);
auto sourceLoc = fallbackLoc.getSourceLoc();
auto &module = badInst->getModule();
if (sourceLoc.isInvalid()) {
diagnose(module.getASTContext(), sourceLoc, diag::constexpr_not_evaluable);
return;
}
for (auto &sourceLoc : llvm::reverse(getUnknownCallStack())) {
// Skip unknown sources.
if (!sourceLoc.isValid())
continue;
auto diag = emittedFirstNote ? diag::constexpr_called_from
: diag::constexpr_not_evaluable;
diagnose(module.getASTContext(), sourceLoc, diag);
emittedFirstNote = true;
}
}
static void diagnoseReturn(const SILInstruction *I, ASTContext &Context) {
auto *TI = dyn_cast<TermInst>(I);
if (!TI || !(isa<BranchInst>(TI) || isa<ReturnInst>(TI)))
return;
const SILBasicBlock *BB = TI->getParent();
const SILFunction *F = BB->getParent();
// Warn if we reach a return inside a noreturn function.
if (F->getLoweredFunctionType()->isNoReturn()) {
SILLocation L = TI->getLoc();
if (L.is<ReturnLocation>())
diagnose(Context, L.getSourceLoc(), diag::return_from_noreturn);
if (L.is<ImplicitReturnLocation>())
diagnose(Context, L.getSourceLoc(), diag::return_from_noreturn);
}
}
SILValue SILGenFunction::emitGlobalFunctionRef(SILLocation loc,
SILDeclRef constant,
SILConstantInfo constantInfo) {
assert(constantInfo == getConstantInfo(constant));
// Builtins must be fully applied at the point of reference.
if (constant.hasDecl() &&
isa<BuiltinUnit>(constant.getDecl()->getDeclContext())) {
SGM.diagnose(loc.getSourceLoc(), diag::not_implemented,
"delayed application of builtin");
return SILUndef::get(constantInfo.getSILType(), SGM.M);
}
// If the constant is a thunk we haven't emitted yet, emit it.
if (!SGM.hasFunction(constant)) {
if (constant.isCurried) {
auto vd = constant.getDecl();
// Reference the next uncurrying level of the function.
SILDeclRef next = SILDeclRef(vd, constant.kind,
SILDeclRef::ConstructAtBestResilienceExpansion,
constant.uncurryLevel + 1);
// If the function is fully uncurried and natively foreign, reference its
// foreign entry point.
if (!next.isCurried) {
if (requiresForeignToNativeThunk(vd))
next = next.asForeign();
}
// Preserve whether the curry thunks lead to a direct reference to the
// method implementation.
next = next.asDirectReference(constant.isDirectReference);
SGM.emitCurryThunk(vd, constant, next);
}
// Otherwise, if this is a calling convention thunk we haven't emitted yet,
// emit it.
else if (constant.isForeignToNativeThunk()) {
SGM.emitForeignToNativeThunk(constant);
} else if (constant.isNativeToForeignThunk()) {
SGM.emitNativeToForeignThunk(constant);
} else if (constant.kind == SILDeclRef::Kind::EnumElement) {
SGM.emitEnumConstructor(cast<EnumElementDecl>(constant.getDecl()));
}
}
auto f = SGM.getFunction(constant, NotForDefinition);
assert(f->getLoweredFunctionType() == constantInfo.SILFnType);
return B.createFunctionRef(loc, f);
}
void swift::printSILLocationDescription(llvm::raw_ostream &out,
SILLocation loc,
ASTContext &Context) {
if (loc.isNull()) {
out << "<<invalid location>>";
} else if (loc.isSILFile()) {
printSourceLocDescription(out, loc.getSourceLoc(), Context);
} else if (auto decl = loc.getAsASTNode<Decl>()) {
printDeclDescription(out, decl, Context);
} else if (auto expr = loc.getAsASTNode<Expr>()) {
printExprDescription(out, expr, Context);
} else if (auto stmt = loc.getAsASTNode<Stmt>()) {
printStmtDescription(out, stmt, Context);
} else if (auto pattern = loc.castToASTNode<Pattern>()) {
printPatternDescription(out, pattern, Context);
}
}
static void emitSourceLocationArgs(SILGenFunction &gen,
SILLocation loc,
ManagedValue (&args)[4]) {
auto &ctx = gen.getASTContext();
auto sourceLoc = loc.getSourceLoc();
StringRef filename = "";
unsigned line = 0;
if (sourceLoc.isValid()) {
unsigned bufferID = ctx.SourceMgr.findBufferContainingLoc(sourceLoc);
filename = ctx.SourceMgr.getIdentifierForBuffer(bufferID);
line = ctx.SourceMgr.getLineAndColumn(sourceLoc).first;
}
bool isASCII = true;
for (unsigned char c : filename) {
if (c > 127) {
isASCII = false;
break;
}
}
auto wordTy = SILType::getBuiltinWordType(ctx);
auto i1Ty = SILType::getBuiltinIntegerType(1, ctx);
// File
SILValue literal = gen.B.createStringLiteral(loc, filename,
StringLiteralInst::Encoding::UTF8);
args[0] = ManagedValue::forUnmanaged(literal);
// File length
literal = gen.B.createIntegerLiteral(loc, wordTy, filename.size());
args[1] = ManagedValue::forUnmanaged(literal);
// File is ascii
literal = gen.B.createIntegerLiteral(loc, i1Ty, isASCII);
args[2] = ManagedValue::forUnmanaged(literal);
// Line
literal = gen.B.createIntegerLiteral(loc, wordTy, line);
args[3] = ManagedValue::forUnmanaged(literal);
}
/// \brief Issue an "unreachable code" diagnostic if the blocks contains or
/// leads to another block that contains user code.
///
/// Note, we rely on SILLocation information to determine if SILInstructions
/// correspond to user code.
static bool diagnoseUnreachableBlock(const SILBasicBlock &B,
SILModule &M,
const SILBasicBlockSet &Reachable,
UnreachableUserCodeReportingState *State,
const SILBasicBlock *TopLevelB,
llvm::SmallPtrSetImpl<const SILBasicBlock*> &Visited){
if (Visited.count(&B))
return false;
Visited.insert(&B);
assert(State);
for (auto I = B.begin(), E = B.end(); I != E; ++I) {
SILLocation Loc = I->getLoc();
// If we've reached an implicit return, we have not found any user code and
// can stop searching for it.
if (Loc.is<ImplicitReturnLocation>() || Loc.isAutoGenerated())
return false;
// Check if the instruction corresponds to user-written code, also make
// sure we don't report an error twice for the same instruction.
if (isUserCode(&*I) && !State->BlocksWithErrors.count(&B)) {
// Emit the diagnostic.
auto BrInfoIter = State->MetaMap.find(TopLevelB);
assert(BrInfoIter != State->MetaMap.end());
auto BrInfo = BrInfoIter->second;
switch (BrInfo.Kind) {
case (UnreachableKind::FoldedBranch):
// Emit the diagnostic on the unreachable block and emit the
// note on the branch responsible for the unreachable code.
diagnose(M.getASTContext(), Loc.getSourceLoc(), diag::unreachable_code);
diagnose(M.getASTContext(), BrInfo.Loc.getSourceLoc(),
diag::unreachable_code_branch, BrInfo.CondIsAlwaysTrue);
break;
case (UnreachableKind::FoldedSwitchEnum): {
// If we are warning about a switch condition being a constant, the main
// emphasis should be on the condition (to ensure we have a single
// message per switch).
const SwitchStmt *SS = BrInfo.Loc.getAsASTNode<SwitchStmt>();
if (!SS)
break;
assert(SS);
const Expr *SE = SS->getSubjectExpr();
diagnose(M.getASTContext(), SE->getLoc(), diag::switch_on_a_constant);
diagnose(M.getASTContext(), Loc.getSourceLoc(),
diag::unreachable_code_note);
break;
}
case (UnreachableKind::NoreturnCall): {
// Specialcase when we are warning about unreachable code after a call
// to a noreturn function.
if (!BrInfo.Loc.isASTNode<ExplicitCastExpr>()) {
assert(BrInfo.Loc.isASTNode<ApplyExpr>());
diagnose(M.getASTContext(), Loc.getSourceLoc(),
diag::unreachable_code);
diagnose(M.getASTContext(), BrInfo.Loc.getSourceLoc(),
diag::call_to_noreturn_note);
}
break;
}
}
// Record that we've reported this unreachable block to avoid duplicates
// in the future.
State->BlocksWithErrors.insert(&B);
return true;
}
}
// This block could be empty if it's terminator has been folded.
if (B.empty())
return false;
// If we have not found user code in this block, inspect it's successors.
// Check if at least one of the successors contains user code.
for (auto I = B.succ_begin(), E = B.succ_end(); I != E; ++I) {
SILBasicBlock *SB = *I;
bool HasReachablePred = false;
for (auto PI = SB->pred_begin(), PE = SB->pred_end(); PI != PE; ++PI) {
if (Reachable.count(*PI))
HasReachablePred = true;
}
// If all of the predecessors of this successor are unreachable, check if
// it contains user code.
if (!HasReachablePred && diagnoseUnreachableBlock(*SB, M, Reachable,
State, TopLevelB, Visited))
return true;
}
return false;
}
ManagedValue
SILGenFunction::emitPreconditionOptionalHasValue(SILLocation loc,
ManagedValue optional) {
// Generate code to the optional is present, and if not, abort with a message
// (provided by the stdlib).
SILBasicBlock *contBB = createBasicBlock();
SILBasicBlock *failBB = createBasicBlock();
bool hadCleanup = optional.hasCleanup();
bool hadLValue = optional.isLValue();
auto noneDecl = getASTContext().getOptionalNoneDecl();
auto someDecl = getASTContext().getOptionalSomeDecl();
if (optional.getType().isAddress()) {
// We forward in the creation routine for
// unchecked_take_enum_data_addr. switch_enum_addr is a +0 operation.
B.createSwitchEnumAddr(loc, optional.getValue(),
/*defaultDest*/ nullptr,
{{someDecl, contBB}, {noneDecl, failBB}});
} else {
B.createSwitchEnum(loc, optional.forward(*this),
/*defaultDest*/ nullptr,
{{someDecl, contBB}, {noneDecl, failBB}});
}
B.emitBlock(failBB);
// Call the standard library implementation of _diagnoseUnexpectedNilOptional.
if (auto diagnoseFailure =
getASTContext().getDiagnoseUnexpectedNilOptional(nullptr)) {
auto args = emitSourceLocationArgs(loc.getSourceLoc(), loc);
emitApplyOfLibraryIntrinsic(loc, diagnoseFailure, SubstitutionMap(),
{
args.filenameStartPointer,
args.filenameLength,
args.filenameIsAscii,
args.line
},
SGFContext());
}
B.createUnreachable(loc);
B.clearInsertionPoint();
B.emitBlock(contBB);
ManagedValue result;
SILType payloadType = optional.getType().getAnyOptionalObjectType();
if (payloadType.isObject()) {
result = B.createOwnedPHIArgument(payloadType);
} else {
result =
B.createUncheckedTakeEnumDataAddr(loc, optional, someDecl, payloadType);
}
if (hadCleanup) {
return result;
}
if (hadLValue) {
return ManagedValue::forLValue(result.forward(*this));
}
return ManagedValue::forUnmanaged(result.forward(*this));
}
static SILInstruction *constantFoldBuiltin(BuiltinInst *BI,
Optional<bool> &ResultsInError) {
const IntrinsicInfo &Intrinsic = BI->getIntrinsicInfo();
SILModule &M = BI->getModule();
// If it's an llvm intrinsic, fold the intrinsic.
if (Intrinsic.ID != llvm::Intrinsic::not_intrinsic)
return constantFoldIntrinsic(BI, Intrinsic.ID, ResultsInError);
// Otherwise, it should be one of the builtin functions.
OperandValueArrayRef Args = BI->getArguments();
const BuiltinInfo &Builtin = BI->getBuiltinInfo();
switch (Builtin.ID) {
default: break;
// Check and fold binary arithmetic with overflow.
#define BUILTIN(id, name, Attrs)
#define BUILTIN_BINARY_OPERATION_WITH_OVERFLOW(id, name, _, attrs, overload) \
case BuiltinValueKind::id:
#include "swift/AST/Builtins.def"
return constantFoldBinaryWithOverflow(BI, Builtin.ID, ResultsInError);
#define BUILTIN(id, name, Attrs)
#define BUILTIN_BINARY_OPERATION(id, name, attrs, overload) \
case BuiltinValueKind::id:
#include "swift/AST/Builtins.def"
return constantFoldBinary(BI, Builtin.ID, ResultsInError);
// Fold comparison predicates.
#define BUILTIN(id, name, Attrs)
#define BUILTIN_BINARY_PREDICATE(id, name, attrs, overload) \
case BuiltinValueKind::id:
#include "swift/AST/Builtins.def"
return constantFoldCompare(BI, Builtin.ID);
case BuiltinValueKind::Trunc:
case BuiltinValueKind::ZExt:
case BuiltinValueKind::SExt:
case BuiltinValueKind::TruncOrBitCast:
case BuiltinValueKind::ZExtOrBitCast:
case BuiltinValueKind::SExtOrBitCast: {
// We can fold if the value being cast is a constant.
auto *V = dyn_cast<IntegerLiteralInst>(Args[0]);
if (!V)
return nullptr;
APInt CastResV = constantFoldCast(V->getValue(), Builtin);
// Add the literal instruction to represent the result of the cast.
SILBuilderWithScope B(BI);
return B.createIntegerLiteral(BI->getLoc(), BI->getType(), CastResV);
}
// Process special builtins that are designed to check for overflows in
// integer conversions.
case BuiltinValueKind::SToSCheckedTrunc:
case BuiltinValueKind::UToUCheckedTrunc:
case BuiltinValueKind::SToUCheckedTrunc:
case BuiltinValueKind::UToSCheckedTrunc:
case BuiltinValueKind::SUCheckedConversion:
case BuiltinValueKind::USCheckedConversion: {
return constantFoldAndCheckIntegerConversions(BI, Builtin, ResultsInError);
}
case BuiltinValueKind::IntToFPWithOverflow: {
// Get the value. It should be a constant in most cases.
// Note, this will not always be a constant, for example, when analyzing
// _convertFromBuiltinIntegerLiteral function itself.
auto *V = dyn_cast<IntegerLiteralInst>(Args[0]);
if (!V)
return nullptr;
APInt SrcVal = V->getValue();
Type DestTy = Builtin.Types[1];
APFloat TruncVal(
DestTy->castTo<BuiltinFloatType>()->getAPFloatSemantics());
APFloat::opStatus ConversionStatus = TruncVal.convertFromAPInt(
SrcVal, /*isSigned=*/true, APFloat::rmNearestTiesToEven);
SILLocation Loc = BI->getLoc();
const ApplyExpr *CE = Loc.getAsASTNode<ApplyExpr>();
// Check for overflow.
if (ConversionStatus & APFloat::opOverflow) {
// If we overflow and are not asked for diagnostics, just return nullptr.
if (!ResultsInError.hasValue())
return nullptr;
SmallString<10> SrcAsString;
SrcVal.toString(SrcAsString, /*radix*/10, true /*isSigned*/);
// Otherwise emit our diagnostics and then return nullptr.
diagnose(M.getASTContext(), Loc.getSourceLoc(),
diag::integer_literal_overflow,
CE ? CE->getType() : DestTy, SrcAsString);
ResultsInError = Optional<bool>(true);
return nullptr;
}
// The call to the builtin should be replaced with the constant value.
SILBuilderWithScope B(BI);
return B.createFloatLiteral(Loc, BI->getType(), TruncVal);
}
case BuiltinValueKind::FPTrunc: {
// Get the value. It should be a constant in most cases.
auto *V = dyn_cast<FloatLiteralInst>(Args[0]);
if (!V)
return nullptr;
APFloat TruncVal = V->getValue();
Type DestTy = Builtin.Types[1];
bool losesInfo;
APFloat::opStatus ConversionStatus = TruncVal.convert(
DestTy->castTo<BuiltinFloatType>()->getAPFloatSemantics(),
APFloat::rmNearestTiesToEven, &losesInfo);
SILLocation Loc = BI->getLoc();
// Check if conversion was successful.
if (ConversionStatus != APFloat::opStatus::opOK &&
ConversionStatus != APFloat::opStatus::opInexact) {
return nullptr;
}
// The call to the builtin should be replaced with the constant value.
SILBuilderWithScope B(BI);
return B.createFloatLiteral(Loc, BI->getType(), TruncVal);
}
case BuiltinValueKind::AssumeNonNegative: {
auto *V = dyn_cast<IntegerLiteralInst>(Args[0]);
if (!V)
return nullptr;
APInt VInt = V->getValue();
if (VInt.isNegative() && ResultsInError.hasValue()) {
diagnose(M.getASTContext(), BI->getLoc().getSourceLoc(),
diag::wrong_non_negative_assumption,
VInt.toString(/*Radix*/ 10, /*Signed*/ true));
ResultsInError = Optional<bool>(true);
}
return V;
}
}
return nullptr;
}
/// \brief Fold arithmetic intrinsics with overflow.
static SILInstruction *
constantFoldBinaryWithOverflow(BuiltinInst *BI, llvm::Intrinsic::ID ID,
bool ReportOverflow,
Optional<bool> &ResultsInError) {
OperandValueArrayRef Args = BI->getArguments();
assert(Args.size() >= 2);
auto *Op1 = dyn_cast<IntegerLiteralInst>(Args[0]);
auto *Op2 = dyn_cast<IntegerLiteralInst>(Args[1]);
// If either Op1 or Op2 is not a literal, we cannot do anything.
if (!Op1 || !Op2)
return nullptr;
// Calculate the result.
APInt LHSInt = Op1->getValue();
APInt RHSInt = Op2->getValue();
bool Overflow;
APInt Res = constantFoldBinaryWithOverflow(LHSInt, RHSInt, Overflow, ID);
// If we can statically determine that the operation overflows,
// warn about it if warnings are not disabled by ResultsInError being null.
if (ResultsInError.hasValue() && Overflow && ReportOverflow) {
// Try to infer the type of the constant expression that the user operates
// on. If the intrinsic was lowered from a call to a function that takes
// two arguments of the same type, use the type of the LHS argument.
// This would detect '+'/'+=' and such.
Type OpType;
SILLocation Loc = BI->getLoc();
const ApplyExpr *CE = Loc.getAsASTNode<ApplyExpr>();
SourceRange LHSRange, RHSRange;
if (CE) {
const auto *Args = dyn_cast_or_null<TupleExpr>(CE->getArg());
if (Args && Args->getNumElements() == 2) {
// Look through inout types in order to handle += well.
CanType LHSTy = Args->getElement(0)->getType()->getInOutObjectType()->
getCanonicalType();
CanType RHSTy = Args->getElement(1)->getType()->getCanonicalType();
if (LHSTy == RHSTy)
OpType = Args->getElement(1)->getType();
LHSRange = Args->getElement(0)->getSourceRange();
RHSRange = Args->getElement(1)->getSourceRange();
}
}
bool Signed = false;
StringRef Operator = "+";
switch (ID) {
default: llvm_unreachable("Invalid case");
case llvm::Intrinsic::sadd_with_overflow:
Signed = true;
break;
case llvm::Intrinsic::uadd_with_overflow:
break;
case llvm::Intrinsic::ssub_with_overflow:
Operator = "-";
Signed = true;
break;
case llvm::Intrinsic::usub_with_overflow:
Operator = "-";
break;
case llvm::Intrinsic::smul_with_overflow:
Operator = "*";
Signed = true;
break;
case llvm::Intrinsic::umul_with_overflow:
Operator = "*";
break;
}
if (!OpType.isNull()) {
diagnose(BI->getModule().getASTContext(),
Loc.getSourceLoc(),
diag::arithmetic_operation_overflow,
LHSInt.toString(/*Radix*/ 10, Signed),
Operator,
RHSInt.toString(/*Radix*/ 10, Signed),
OpType).highlight(LHSRange).highlight(RHSRange);
} else {
// If we cannot get the type info in an expected way, describe the type.
diagnose(BI->getModule().getASTContext(),
Loc.getSourceLoc(),
diag::arithmetic_operation_overflow_generic_type,
LHSInt.toString(/*Radix*/ 10, Signed),
Operator,
RHSInt.toString(/*Radix*/ 10, Signed),
Signed,
LHSInt.getBitWidth()).highlight(LHSRange).highlight(RHSRange);
}
ResultsInError = Optional<bool>(true);
}
return constructResultWithOverflowTuple(BI, Res, Overflow);
}
static SILInstruction *
constantFoldAndCheckIntegerConversions(BuiltinInst *BI,
const BuiltinInfo &Builtin,
Optional<bool> &ResultsInError) {
assert(Builtin.ID == BuiltinValueKind::SToSCheckedTrunc ||
Builtin.ID == BuiltinValueKind::UToUCheckedTrunc ||
Builtin.ID == BuiltinValueKind::SToUCheckedTrunc ||
Builtin.ID == BuiltinValueKind::UToSCheckedTrunc ||
Builtin.ID == BuiltinValueKind::SUCheckedConversion ||
Builtin.ID == BuiltinValueKind::USCheckedConversion);
// Check if we are converting a constant integer.
OperandValueArrayRef Args = BI->getArguments();
auto *V = dyn_cast<IntegerLiteralInst>(Args[0]);
if (!V)
return nullptr;
APInt SrcVal = V->getValue();
// Get source type and bit width.
Type SrcTy = Builtin.Types[0];
uint32_t SrcBitWidth =
Builtin.Types[0]->castTo<BuiltinIntegerType>()->getGreatestWidth();
// Compute the destination (for SrcBitWidth < DestBitWidth) and enough info
// to check for overflow.
APInt Result;
bool OverflowError;
Type DstTy;
// Process conversions signed <-> unsigned for same size integers.
if (Builtin.ID == BuiltinValueKind::SUCheckedConversion ||
Builtin.ID == BuiltinValueKind::USCheckedConversion) {
DstTy = SrcTy;
Result = SrcVal;
// Report an error if the sign bit is set.
OverflowError = SrcVal.isNegative();
// Process truncation from unsigned to signed.
} else if (Builtin.ID != BuiltinValueKind::UToSCheckedTrunc) {
assert(Builtin.Types.size() == 2);
DstTy = Builtin.Types[1];
uint32_t DstBitWidth =
DstTy->castTo<BuiltinIntegerType>()->getGreatestWidth();
// Result = trunc_IntFrom_IntTo(Val)
// For signed destination:
// sext_IntFrom(Result) == Val ? Result : overflow_error
// For signed destination:
// zext_IntFrom(Result) == Val ? Result : overflow_error
Result = SrcVal.trunc(DstBitWidth);
// Get the signedness of the destination.
bool Signed = (Builtin.ID == BuiltinValueKind::SToSCheckedTrunc);
APInt Ext = Signed ? Result.sext(SrcBitWidth) : Result.zext(SrcBitWidth);
OverflowError = (SrcVal != Ext);
// Process the rest of truncations.
} else {
assert(Builtin.Types.size() == 2);
DstTy = Builtin.Types[1];
uint32_t DstBitWidth =
Builtin.Types[1]->castTo<BuiltinIntegerType>()->getGreatestWidth();
// Compute the destination (for SrcBitWidth < DestBitWidth):
// Result = trunc_IntTo(Val)
// Trunc = trunc_'IntTo-1bit'(Val)
// zext_IntFrom(Trunc) == Val ? Result : overflow_error
Result = SrcVal.trunc(DstBitWidth);
APInt TruncVal = SrcVal.trunc(DstBitWidth - 1);
OverflowError = (SrcVal != TruncVal.zext(SrcBitWidth));
}
// Check for overflow.
if (OverflowError) {
// If we are not asked to emit overflow diagnostics, just return nullptr on
// overflow.
if (!ResultsInError.hasValue())
return nullptr;
SILLocation Loc = BI->getLoc();
SILModule &M = BI->getModule();
const ApplyExpr *CE = Loc.getAsASTNode<ApplyExpr>();
Type UserSrcTy;
Type UserDstTy;
// Primitive heuristics to get the user-written type.
// Eventually we might be able to use SILLocation (when it contains info
// about inlined call chains).
if (CE) {
if (const TupleType *RTy = CE->getArg()->getType()->getAs<TupleType>()) {
if (RTy->getNumElements() == 1) {
UserSrcTy = RTy->getElementType(0);
UserDstTy = CE->getType();
}
} else {
UserSrcTy = CE->getArg()->getType();
UserDstTy = CE->getType();
}
}
// Assume that we are converting from a literal if the Source size is
// 2048. Is there a better way to identify conversions from literals?
bool Literal = (SrcBitWidth == 2048);
// FIXME: This will prevent hard error in cases the error is coming
// from ObjC interoperability code. Currently, we treat NSUInteger as
// Int.
if (Loc.getSourceLoc().isInvalid()) {
// Otherwise emit the appropriate diagnostic and set ResultsInError.
if (Literal)
diagnose(M.getASTContext(), Loc.getSourceLoc(),
diag::integer_literal_overflow_warn,
UserDstTy.isNull() ? DstTy : UserDstTy);
else
diagnose(M.getASTContext(), Loc.getSourceLoc(),
diag::integer_conversion_overflow_warn,
UserSrcTy.isNull() ? SrcTy : UserSrcTy,
UserDstTy.isNull() ? DstTy : UserDstTy);
ResultsInError = Optional<bool>(true);
return nullptr;
}
// Otherwise report the overflow error.
if (Literal) {
bool SrcTySigned, DstTySigned;
std::tie(SrcTySigned, DstTySigned) = getTypeSignedness(Builtin);
SmallString<10> SrcAsString;
SrcVal.toString(SrcAsString, /*radix*/10, SrcTySigned);
// Try to print user-visible types if they are available.
if (!UserDstTy.isNull()) {
auto diagID = diag::integer_literal_overflow;
// If this is a negative literal in an unsigned type, use a specific
// diagnostic.
if (SrcTySigned && !DstTySigned && SrcVal.isNegative())
diagID = diag::negative_integer_literal_overflow_unsigned;
diagnose(M.getASTContext(), Loc.getSourceLoc(),
diagID, UserDstTy, SrcAsString);
// Otherwise, print the Builtin Types.
} else {
bool SrcTySigned, DstTySigned;
std::tie(SrcTySigned, DstTySigned) = getTypeSignedness(Builtin);
diagnose(M.getASTContext(), Loc.getSourceLoc(),
diag::integer_literal_overflow_builtin_types,
DstTySigned, DstTy, SrcAsString);
}
} else {
if (Builtin.ID == BuiltinValueKind::SUCheckedConversion) {
diagnose(M.getASTContext(), Loc.getSourceLoc(),
diag::integer_conversion_sign_error,
UserDstTy.isNull() ? DstTy : UserDstTy);
} else {
// Try to print user-visible types if they are available.
if (!UserSrcTy.isNull()) {
diagnose(M.getASTContext(), Loc.getSourceLoc(),
diag::integer_conversion_overflow,
UserSrcTy, UserDstTy);
// Otherwise, print the Builtin Types.
} else {
// Since builtin types are sign-agnostic, print the signedness
// separately.
bool SrcTySigned, DstTySigned;
std::tie(SrcTySigned, DstTySigned) = getTypeSignedness(Builtin);
diagnose(M.getASTContext(), Loc.getSourceLoc(),
diag::integer_conversion_overflow_builtin_types,
SrcTySigned, SrcTy, DstTySigned, DstTy);
}
}
}
ResultsInError = Optional<bool>(true);
return nullptr;
}
// The call to the builtin should be replaced with the constant value.
return constructResultWithOverflowTuple(BI, Result, false);
}