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a0f20f673dab2843f1c65c472748d179662073e5
swift-mirror/lib/IRGen/GenFunc.cpp
John McCall a0f20f673d Switch all of the indirect-call code in IRGen to FunctionPointer. 
To make this stick, I've disallowed direct use of that overload of
CreateCall.  I've left the Constant overloads available, but eventually
we might want to consider fixing those, too, just to get all of this
code out of the business of manually remembering to pass around
attributes and calling conventions.

The test changes reflect the fact that we weren't really setting
attributes consistently at all, in this case on value witnesses.
2017-07-28 23:26:35 -04:00

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//===--- GenFunc.cpp - Swift IR Generation for Function Types -------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
//
// This file implements IR generation for function types in Swift. This
// includes creating the IR type as well as capturing variables and
// performing calls.
//
// Swift supports three representations of functions:
//
// - thin, which are just a function pointer;
//
// - thick, which are a pair of a function pointer and
// an optional ref-counted opaque context pointer; and
//
// - block, which match the Apple blocks extension: a ref-counted
// pointer to a mostly-opaque structure with the function pointer
// stored at a fixed offset.
//
// The order of function parameters is as follows:
//
// - indirect return pointer
// - block context parameter, if applicable
// - expanded formal parameter types
// - implicit generic parameters
// - thick context parameter, if applicable
// - error result out-parameter, if applicable
// - witness_method generic parameters, if applicable
//
// The context and error parameters are last because they are
// optional: we'd like to be able to turn a thin function into a
// thick function, or a non-throwing function into a throwing one,
// without adding a thunk. A thick context parameter is required
// (but can be passed undef) if an error result is required.
//
// The additional generic parameters for witness methods follow the
// same logic: we'd like to be able to use non-generic method
// implementations directly as protocol witnesses if the rest of the
// ABI matches up.
//
// Note that some of this business with context parameters and error
// results is just IR formalism; on most of our targets, both of
// these are passed in registers. This is also why passing them
// as the final argument isn't bad for performance.
//
// For now, function pointer types are always stored as opaque
// pointers in LLVM IR; using a well-typed function type is
// very challenging because of issues with recursive type expansion,
// which can potentially introduce infinite types. For example:
// struct A {
// var fn: (A) -> ()
// }
// Our CC lowering expands the fields of A into the argument list
// of A.fn, which is necessarily infinite. Attempting to use better
// types when not in a situation like this would just make the
// compiler complacent, leading to a long tail of undiscovered
// crashes. So instead we always store as i8* and require the
// bitcast whenever we change representations.
//
//===----------------------------------------------------------------------===//
#include "swift/AST/ASTContext.h"
#include "swift/AST/ASTWalker.h"
#include "swift/AST/Builtins.h"
#include "swift/AST/Decl.h"
#include "swift/AST/IRGenOptions.h"
#include "swift/AST/Module.h"
#include "swift/AST/Pattern.h"
#include "swift/AST/PrettyStackTrace.h"
#include "swift/AST/SubstitutionMap.h"
#include "swift/AST/Types.h"
#include "clang/CodeGen/CodeGenABITypes.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/Module.h"
#include "llvm/ProfileData/InstrProf.h"
#include "llvm/Support/Debug.h"
#include "llvm/ADT/StringSwitch.h"
#include "Callee.h"
#include "ConstantBuilder.h"
#include "EnumPayload.h"
#include "Explosion.h"
#include "FixedTypeInfo.h"
#include "GenCall.h"
#include "GenClass.h"
#include "GenFunc.h"
#include "GenHeap.h"
#include "GenMeta.h"
#include "GenObjC.h"
#include "GenPoly.h"
#include "GenProto.h"
#include "GenType.h"
#include "HeapTypeInfo.h"
#include "IRGenDebugInfo.h"
#include "IRGenFunction.h"
#include "IRGenModule.h"
#include "IndirectTypeInfo.h"
#include "NativeConventionSchema.h"
#include "ScalarTypeInfo.h"
#include "Signature.h"
#include "IRGenMangler.h"
using namespace swift;
using namespace irgen;
namespace {
/// Information about the IR-level signature of a function type.
class FuncSignatureInfo {
private:
/// The SIL function type being represented.
const CanSILFunctionType FormalType;
mutable Signature TheSignature;
public:
FuncSignatureInfo(CanSILFunctionType formalType)
: FormalType(formalType) {}
Signature getSignature(IRGenModule &IGM) const;
};
/// The @thin function type-info class.
class ThinFuncTypeInfo : public PODSingleScalarTypeInfo<ThinFuncTypeInfo,
LoadableTypeInfo>,
public FuncSignatureInfo {
ThinFuncTypeInfo(CanSILFunctionType formalType, llvm::Type *storageType,
Size size, Alignment align,
const SpareBitVector &spareBits)
: PODSingleScalarTypeInfo(storageType, size, spareBits, align),
FuncSignatureInfo(formalType)
{
}
public:
static const ThinFuncTypeInfo *create(CanSILFunctionType formalType,
llvm::Type *storageType,
Size size, Alignment align,
const SpareBitVector &spareBits) {
return new ThinFuncTypeInfo(formalType, storageType, size, align,
spareBits);
}
bool mayHaveExtraInhabitants(IRGenModule &IGM) const override {
return true;
}
unsigned getFixedExtraInhabitantCount(IRGenModule &IGM) const override {
return getFunctionPointerExtraInhabitantCount(IGM);
}
APInt getFixedExtraInhabitantValue(IRGenModule &IGM,
unsigned bits,
unsigned index) const override {
return getFunctionPointerFixedExtraInhabitantValue(IGM, bits, index, 0);
}
llvm::Value *getExtraInhabitantIndex(IRGenFunction &IGF, Address src,
SILType T)
const override {
return getFunctionPointerExtraInhabitantIndex(IGF, src);
}
void storeExtraInhabitant(IRGenFunction &IGF, llvm::Value *index,
Address dest, SILType T) const override {
return storeFunctionPointerExtraInhabitant(IGF, index, dest);
}
};
/// The @thick function type-info class.
class FuncTypeInfo : public ScalarTypeInfo<FuncTypeInfo, ReferenceTypeInfo>,
public FuncSignatureInfo {
FuncTypeInfo(CanSILFunctionType formalType, llvm::StructType *storageType,
Size size, Alignment align, SpareBitVector &&spareBits,
IsPOD_t pod)
: ScalarTypeInfo(storageType, size, std::move(spareBits), align, pod),
FuncSignatureInfo(formalType)
{
}
public:
static const FuncTypeInfo *create(CanSILFunctionType formalType,
llvm::StructType *storageType,
Size size, Alignment align,
SpareBitVector &&spareBits,
IsPOD_t pod) {
return new FuncTypeInfo(formalType, storageType, size, align,
std::move(spareBits), pod);
}
// Function types do not satisfy allowsOwnership.
const WeakTypeInfo *
createWeakStorageType(TypeConverter &TC) const override {
llvm_unreachable("[weak] function type");
}
const TypeInfo *
createUnownedStorageType(TypeConverter &TC) const override {
llvm_unreachable("[unowned] function type");
}
const TypeInfo *
createUnmanagedStorageType(TypeConverter &TC) const override {
llvm_unreachable("@unowned(unsafe) function type");
}
llvm::StructType *getStorageType() const {
return cast<llvm::StructType>(TypeInfo::getStorageType());
}
unsigned getExplosionSize() const override {
return 2;
}
void getSchema(ExplosionSchema &schema) const override {
llvm::StructType *structTy = getStorageType();
schema.add(ExplosionSchema::Element::forScalar(structTy->getElementType(0)));
schema.add(ExplosionSchema::Element::forScalar(structTy->getElementType(1)));
}
void addToAggLowering(IRGenModule &IGM, SwiftAggLowering &lowering,
Size offset) const override {
auto ptrSize = IGM.getPointerSize();
llvm::StructType *structTy = getStorageType();
addScalarToAggLowering(IGM, lowering, structTy->getElementType(0),
offset, ptrSize);
addScalarToAggLowering(IGM, lowering, structTy->getElementType(1),
offset + ptrSize, ptrSize);
}
Address projectFunction(IRGenFunction &IGF, Address address) const {
return IGF.Builder.CreateStructGEP(address, 0, Size(0),
address->getName() + ".fn");
}
Address projectData(IRGenFunction &IGF, Address address) const {
return IGF.Builder.CreateStructGEP(address, 1, IGF.IGM.getPointerSize(),
address->getName() + ".data");
}
void loadAsCopy(IRGenFunction &IGF, Address address,
Explosion &e) const override {
// Load the function.
Address fnAddr = projectFunction(IGF, address);
e.add(IGF.Builder.CreateLoad(fnAddr, fnAddr->getName()+".load"));
Address dataAddr = projectData(IGF, address);
auto data = IGF.Builder.CreateLoad(dataAddr);
if (!isPOD(ResilienceExpansion::Maximal))
IGF.emitNativeStrongRetain(data, IGF.getDefaultAtomicity());
e.add(data);
}
void loadAsTake(IRGenFunction &IGF, Address addr,
Explosion &e) const override {
// Load the function.
Address fnAddr = projectFunction(IGF, addr);
e.add(IGF.Builder.CreateLoad(fnAddr));
Address dataAddr = projectData(IGF, addr);
e.add(IGF.Builder.CreateLoad(dataAddr));
}
void assign(IRGenFunction &IGF, Explosion &e,
Address address) const override {
// Store the function pointer.
Address fnAddr = projectFunction(IGF, address);
IGF.Builder.CreateStore(e.claimNext(), fnAddr);
Address dataAddr = projectData(IGF, address);
auto context = e.claimNext();
if (isPOD(ResilienceExpansion::Maximal))
IGF.Builder.CreateStore(context, dataAddr);
else
IGF.emitNativeStrongAssign(context, dataAddr);
}
void initialize(IRGenFunction &IGF, Explosion &e,
Address address) const override {
// Store the function pointer.
Address fnAddr = projectFunction(IGF, address);
IGF.Builder.CreateStore(e.claimNext(), fnAddr);
// Store the data pointer, if any, transferring the +1.
Address dataAddr = projectData(IGF, address);
auto context = e.claimNext();
if (isPOD(ResilienceExpansion::Maximal))
IGF.Builder.CreateStore(context, dataAddr);
else
IGF.emitNativeStrongInit(context, dataAddr);
}
void copy(IRGenFunction &IGF, Explosion &src,
Explosion &dest, Atomicity atomicity) const override {
src.transferInto(dest, 1);
auto data = src.claimNext();
if (!isPOD(ResilienceExpansion::Maximal))
IGF.emitNativeStrongRetain(data, atomicity);
dest.add(data);
}
void consume(IRGenFunction &IGF, Explosion &src,
Atomicity atomicity) const override {
src.claimNext();
auto context = src.claimNext();
if (!isPOD(ResilienceExpansion::Maximal))
IGF.emitNativeStrongRelease(context, atomicity);
}
void fixLifetime(IRGenFunction &IGF, Explosion &src) const override {
src.claimNext();
IGF.emitFixLifetime(src.claimNext());
}
void strongRetain(IRGenFunction &IGF, Explosion &e,
Atomicity atomicity) const override {
e.claimNext();
auto context = e.claimNext();
if (!isPOD(ResilienceExpansion::Maximal))
IGF.emitNativeStrongRetain(context, atomicity);
}
void strongRelease(IRGenFunction &IGF, Explosion &e,
Atomicity atomicity) const override {
e.claimNext();
auto context = e.claimNext();
if (!isPOD(ResilienceExpansion::Maximal))
IGF.emitNativeStrongRelease(context, atomicity);
}
void strongRetainUnowned(IRGenFunction &IGF, Explosion &e,
Atomicity atomicity) const override {
llvm_unreachable("unowned references to functions are not supported");
}
void strongRetainUnownedRelease(IRGenFunction &IGF,
Explosion &e,
Atomicity atomicity) const override {
llvm_unreachable("unowned references to functions are not supported");
}
void unownedRetain(IRGenFunction &IGF, Explosion &e,
Atomicity atomicity) const override {
llvm_unreachable("unowned references to functions are not supported");
}
void unownedRelease(IRGenFunction &IGF, Explosion &e,
Atomicity atomicity) const override {
llvm_unreachable("unowned references to functions are not supported");
}
void unownedLoadStrong(IRGenFunction &IGF, Address src,
Explosion &out) const override {
llvm_unreachable("unowned references to functions are not supported");
}
void unownedTakeStrong(IRGenFunction &IGF, Address src,
Explosion &out) const override {
llvm_unreachable("unowned references to functions are not supported");
}
void unownedInit(IRGenFunction &IGF, Explosion &in,
Address dest) const override {
llvm_unreachable("unowned references to functions are not supported");
}
void unownedAssign(IRGenFunction &IGF, Explosion &in,
Address dest) const override {
llvm_unreachable("unowned references to functions are not supported");
}
void destroy(IRGenFunction &IGF, Address addr, SILType T) const override {
auto data = IGF.Builder.CreateLoad(projectData(IGF, addr));
if (!isPOD(ResilienceExpansion::Maximal))
IGF.emitNativeStrongRelease(data, IGF.getDefaultAtomicity());
}
void packIntoEnumPayload(IRGenFunction &IGF,
EnumPayload &payload,
Explosion &src,
unsigned offset) const override {
payload.insertValue(IGF, src.claimNext(), offset);
payload.insertValue(IGF, src.claimNext(),
offset + IGF.IGM.getPointerSize().getValueInBits());
}
void unpackFromEnumPayload(IRGenFunction &IGF,
const EnumPayload &payload,
Explosion &dest,
unsigned offset) const override {
auto storageTy = getStorageType();
dest.add(payload.extractValue(IGF, storageTy->getElementType(0), offset));
dest.add(payload.extractValue(IGF, storageTy->getElementType(1),
offset + IGF.IGM.getPointerSize().getValueInBits()));
}
bool mayHaveExtraInhabitants(IRGenModule &IGM) const override {
return true;
}
unsigned getFixedExtraInhabitantCount(IRGenModule &IGM) const override {
return getFunctionPointerExtraInhabitantCount(IGM);
}
APInt getFixedExtraInhabitantValue(IRGenModule &IGM,
unsigned bits,
unsigned index) const override {
return getFunctionPointerFixedExtraInhabitantValue(IGM, bits, index, 0);
}
llvm::Value *getExtraInhabitantIndex(IRGenFunction &IGF, Address src,
SILType T) const override {
src = projectFunction(IGF, src);
return getFunctionPointerExtraInhabitantIndex(IGF, src);
}
APInt getFixedExtraInhabitantMask(IRGenModule &IGM) const override {
// Only the function pointer value is used for extra inhabitants.
auto pointerSize = IGM.getPointerSize().getValueInBits();
APInt bits = APInt::getAllOnesValue(pointerSize);
bits = bits.zext(pointerSize * 2);
return bits;
}
void storeExtraInhabitant(IRGenFunction &IGF, llvm::Value *index,
Address dest, SILType T) const override {
dest = projectFunction(IGF, dest);
return storeFunctionPointerExtraInhabitant(IGF, index, dest);
}
};
/// The type-info class for ObjC blocks, which are represented by an ObjC
/// heap pointer.
class BlockTypeInfo : public HeapTypeInfo<BlockTypeInfo>,
public FuncSignatureInfo
{
public:
BlockTypeInfo(CanSILFunctionType ty,
llvm::PointerType *storageType,
Size size, SpareBitVector spareBits, Alignment align)
: HeapTypeInfo(storageType, size, spareBits, align),
FuncSignatureInfo(ty)
{
}
ReferenceCounting getReferenceCounting() const {
return ReferenceCounting::Block;
}
};
/// The type info class for the on-stack representation of an ObjC block.
///
/// TODO: May not be fixed-layout if we capture generics.
class BlockStorageTypeInfo final
: public IndirectTypeInfo<BlockStorageTypeInfo, FixedTypeInfo>
{
Size CaptureOffset;
public:
BlockStorageTypeInfo(llvm::Type *type, Size size, Alignment align,
SpareBitVector &&spareBits,
IsPOD_t pod, IsBitwiseTakable_t bt, Size captureOffset)
: IndirectTypeInfo(type, size, std::move(spareBits), align, pod, bt,
IsFixedSize),
CaptureOffset(captureOffset)
{}
// The lowered type should be an LLVM struct comprising the block header
// (IGM.ObjCBlockStructTy) as its first element and the capture as its
// second.
Address projectBlockHeader(IRGenFunction &IGF, Address storage) const {
return IGF.Builder.CreateStructGEP(storage, 0, Size(0));
}
Address projectCapture(IRGenFunction &IGF, Address storage) const {
return IGF.Builder.CreateStructGEP(storage, 1, CaptureOffset);
}
// TODO
// The frontend will currently never emit copy_addr or destroy_addr for
// block storage.
void assignWithCopy(IRGenFunction &IGF, Address dest,
Address src, SILType T) const override {
IGF.unimplemented(SourceLoc(), "copying @block_storage");
}
void initializeWithCopy(IRGenFunction &IGF, Address dest,
Address src, SILType T) const override {
IGF.unimplemented(SourceLoc(), "copying @block_storage");
}
void destroy(IRGenFunction &IGF, Address addr, SILType T) const override {
IGF.unimplemented(SourceLoc(), "destroying @block_storage");
}
};
} // end anonymous namespace
const TypeInfo *TypeConverter::convertBlockStorageType(SILBlockStorageType *T) {
// The block storage consists of the block header (ObjCBlockStructTy)
// followed by the lowered type of the capture.
auto &capture = IGM.getTypeInfoForLowered(T->getCaptureType());
// TODO: Support dynamic-sized captures.
const auto *fixedCapture = dyn_cast<FixedTypeInfo>(&capture);
llvm::Type *fixedCaptureTy;
// The block header is pointer aligned. The capture may be worse aligned.
Alignment align = IGM.getPointerAlignment();
Size captureOffset(
IGM.DataLayout.getStructLayout(IGM.ObjCBlockStructTy)->getSizeInBytes());
Size size = captureOffset;
SpareBitVector spareBits =
SpareBitVector::getConstant(size.getValueInBits(), false);
IsPOD_t pod = IsNotPOD;
IsBitwiseTakable_t bt = IsNotBitwiseTakable;
if (!fixedCapture) {
IGM.unimplemented(SourceLoc(), "dynamic @block_storage capture");
fixedCaptureTy = llvm::StructType::get(IGM.getLLVMContext(), {});
} else {
fixedCaptureTy = cast<FixedTypeInfo>(capture).getStorageType();
align = std::max(align, fixedCapture->getFixedAlignment());
captureOffset = captureOffset.roundUpToAlignment(align);
spareBits.extendWithSetBits(captureOffset.getValueInBits());
size = captureOffset + fixedCapture->getFixedSize();
spareBits.append(fixedCapture->getSpareBits());
pod = fixedCapture->isPOD(ResilienceExpansion::Maximal);
bt = fixedCapture->isBitwiseTakable(ResilienceExpansion::Maximal);
}
llvm::Type *storageElts[] = {
IGM.ObjCBlockStructTy,
fixedCaptureTy,
};
auto storageTy = llvm::StructType::get(IGM.getLLVMContext(), storageElts,
/*packed*/ false);
return new BlockStorageTypeInfo(storageTy, size, align, std::move(spareBits),
pod, bt, captureOffset);
}
Address irgen::projectBlockStorageCapture(IRGenFunction &IGF,
Address storageAddr,
CanSILBlockStorageType storageTy) {
auto &tl = IGF.getTypeInfoForLowered(storageTy).as<BlockStorageTypeInfo>();
return tl.projectCapture(IGF, storageAddr);
}
const TypeInfo *TypeConverter::convertFunctionType(SILFunctionType *T) {
switch (T->getRepresentation()) {
case SILFunctionType::Representation::Block:
return new BlockTypeInfo(CanSILFunctionType(T),
IGM.ObjCBlockPtrTy,
IGM.getPointerSize(),
IGM.getHeapObjectSpareBits(),
IGM.getPointerAlignment());
case SILFunctionType::Representation::Thin:
case SILFunctionType::Representation::Method:
case SILFunctionType::Representation::WitnessMethod:
case SILFunctionType::Representation::ObjCMethod:
case SILFunctionType::Representation::CFunctionPointer:
case SILFunctionType::Representation::Closure:
return ThinFuncTypeInfo::create(CanSILFunctionType(T),
IGM.FunctionPtrTy,
IGM.getPointerSize(),
IGM.getPointerAlignment(),
IGM.getFunctionPointerSpareBits());
case SILFunctionType::Representation::Thick: {
SpareBitVector spareBits;
spareBits.append(IGM.getFunctionPointerSpareBits());
spareBits.append(IGM.getHeapObjectSpareBits());
return FuncTypeInfo::create(CanSILFunctionType(T),
IGM.FunctionPairTy,
IGM.getPointerSize() * 2,
IGM.getPointerAlignment(),
std::move(spareBits),
IsNotPOD);
}
}
llvm_unreachable("bad function type representation");
}
Signature FuncSignatureInfo::getSignature(IRGenModule &IGM) const {
// If it's already been filled in, we're done.
if (TheSignature.isValid())
return TheSignature;
// Update the cache and return.
TheSignature = Signature::getUncached(IGM, FormalType);
assert(TheSignature.isValid());
return TheSignature;
}
static const FuncSignatureInfo &
getFuncSignatureInfoForLowered(IRGenModule &IGM, CanSILFunctionType type) {
auto &ti = IGM.getTypeInfoForLowered(type);
switch (type->getRepresentation()) {
case SILFunctionType::Representation::Block:
return ti.as<BlockTypeInfo>();
case SILFunctionType::Representation::Thin:
case SILFunctionType::Representation::CFunctionPointer:
case SILFunctionType::Representation::Method:
case SILFunctionType::Representation::WitnessMethod:
case SILFunctionType::Representation::ObjCMethod:
case SILFunctionType::Representation::Closure:
return ti.as<ThinFuncTypeInfo>();
case SILFunctionType::Representation::Thick:
return ti.as<FuncTypeInfo>();
}
llvm_unreachable("bad function type representation");
}
Signature
IRGenModule::getSignature(CanSILFunctionType type) {
auto &sigInfo = getFuncSignatureInfoForLowered(*this, type);
return sigInfo.getSignature(*this);
}
llvm::FunctionType *
IRGenModule::getFunctionType(CanSILFunctionType type,
llvm::AttributeSet &attrs,
ForeignFunctionInfo *foreignInfo) {
auto &sigInfo = getFuncSignatureInfoForLowered(*this, type);
Signature sig = sigInfo.getSignature(*this);
attrs = sig.getAttributes();
if (foreignInfo) *foreignInfo = sig.getForeignInfo();
return sig.getType();
}
ForeignFunctionInfo
IRGenModule::getForeignFunctionInfo(CanSILFunctionType type) {
if (type->getLanguage() == SILFunctionLanguage::Swift)
return ForeignFunctionInfo();
auto &sigInfo = getFuncSignatureInfoForLowered(*this, type);
return sigInfo.getSignature(*this).getForeignInfo();
}
static void emitApplyArgument(IRGenFunction &IGF,
SILParameterInfo origParam,
SILParameterInfo substParam,
Explosion &in,
Explosion &out) {
auto silConv = IGF.IGM.silConv;
bool isSubstituted =
(silConv.getSILType(substParam) != silConv.getSILType(origParam));
// For indirect arguments, we just need to pass a pointer.
if (silConv.isSILIndirect(origParam)) {
// This address is of the substituted type.
auto addr = in.claimNext();
// If a substitution is in play, just bitcast the address.
if (isSubstituted) {
auto origType =
IGF.IGM.getStoragePointerType(silConv.getSILType(origParam));
addr = IGF.Builder.CreateBitCast(addr, origType);
}
out.add(addr);
return;
}
assert(!silConv.isSILIndirect(origParam)
&& "Unexpected opaque apply parameter.");
// Otherwise, it's an explosion, which we may need to translate,
// both in terms of explosion level and substitution levels.
// Handle the last unsubstituted case.
if (!isSubstituted) {
auto &substArgTI =
cast<LoadableTypeInfo>(IGF.getTypeInfo(silConv.getSILType(substParam)));
substArgTI.reexplode(IGF, in, out);
return;
}
reemitAsUnsubstituted(IGF, silConv.getSILType(origParam),
silConv.getSILType(substParam), in, out);
}
static CanType getArgumentLoweringType(CanType type,
SILParameterInfo paramInfo) {
switch (paramInfo.getConvention()) {
// Capture value parameters by value, consuming them.
case ParameterConvention::Direct_Owned:
case ParameterConvention::Direct_Unowned:
case ParameterConvention::Direct_Guaranteed:
case ParameterConvention::Indirect_In:
case ParameterConvention::Indirect_In_Constant:
case ParameterConvention::Indirect_In_Guaranteed:
return type;
// Capture inout parameters by pointer.
case ParameterConvention::Indirect_Inout:
case ParameterConvention::Indirect_InoutAliasable:
return CanInOutType::get(type);
}
}
static bool isABIIgnoredParameterWithoutStorage(IRGenModule &IGM,
IRGenFunction &IGF,
CanSILFunctionType substType,
unsigned paramIdx) {
auto param = substType->getParameters()[paramIdx];
SILType argType = IGM.silConv.getSILType(param);
auto argLoweringTy =
getArgumentLoweringType(argType.getSwiftRValueType(), param);
auto &ti = IGF.getTypeInfoForLowered(argLoweringTy);
// Empty values don't matter.
return ti.getSchema().size() == 0 && !param.isFormalIndirect();
}
/// Find the parameter index for the one (assuming there was only one) partially
/// applied argument ignoring empty types that are not passed as part of the
/// ABI.
static unsigned findSinglePartiallyAppliedParameterIndexIgnoringEmptyTypes(
IRGenFunction &IGF, CanSILFunctionType substType,
CanSILFunctionType outType) {
auto substParameters = substType->getParameters();
auto outParamters = outType->getParameters();
unsigned firstNonEmpty = -1U;
for (unsigned paramIdx = outParamters.size() ; paramIdx != substParameters.size(); ++paramIdx) {
bool isEmpty =
isABIIgnoredParameterWithoutStorage(IGF.IGM, IGF, substType, paramIdx);
assert((isEmpty || firstNonEmpty == -1U) && "Expect at most one partially "
"applied that is passed as an "
"ABI argument");
if (!isEmpty)
firstNonEmpty = paramIdx;
}
assert(firstNonEmpty != -1U);
return firstNonEmpty;
}
/// Emit the forwarding stub function for a partial application.
///
/// If 'layout' is null, there is a single captured value of
/// Swift-refcountable type that is being used directly as the
/// context object.
static llvm::Function *emitPartialApplicationForwarder(IRGenModule &IGM,
llvm::Function *staticFnPtr,
bool calleeHasContext,
const Signature &origSig,
CanSILFunctionType origType,
CanSILFunctionType substType,
CanSILFunctionType outType,
SubstitutionList subs,
HeapLayout const *layout,
ArrayRef<ParameterConvention> conventions) {
auto outSig = IGM.getSignature(outType);
llvm::AttributeSet outAttrs = outSig.getAttributes();
llvm::FunctionType *fwdTy = outSig.getType();
SILFunctionConventions outConv(outType, IGM.getSILModule());
StringRef FnName;
if (staticFnPtr)
FnName = staticFnPtr->getName();
IRGenMangler Mangler;
std::string thunkName = Mangler.manglePartialApplyForwarder(FnName);
// FIXME: Maybe cache the thunk by function and closure types?.
llvm::Function *fwd =
llvm::Function::Create(fwdTy, llvm::Function::InternalLinkage,
llvm::StringRef(thunkName), &IGM.Module);
fwd->setCallingConv(outSig.getCallingConv());
auto initialAttrs = IGM.constructInitialAttributes();
// Merge initialAttrs with outAttrs.
auto updatedAttrs = outAttrs.addAttributes(IGM.getLLVMContext(),
llvm::AttributeSet::FunctionIndex, initialAttrs);
fwd->setAttributes(updatedAttrs);
IRGenFunction subIGF(IGM, fwd);
if (IGM.DebugInfo)
IGM.DebugInfo->emitArtificialFunction(subIGF, fwd);
Explosion origParams = subIGF.collectParameters();
// Create a new explosion for potentially reabstracted parameters.
Explosion args;
Address resultValueAddr;
{
// Lower the forwarded arguments in the original function's generic context.
GenericContextScope scope(IGM, origType->getGenericSignature());
SILFunctionConventions origConv(origType, IGM.getSILModule());
auto &outResultTI = IGM.getTypeInfo(outConv.getSILResultType());
auto &nativeResultSchema = outResultTI.nativeReturnValueSchema(IGM);
auto &origResultTI = IGM.getTypeInfo(origConv.getSILResultType());
auto &origNativeSchema = origResultTI.nativeReturnValueSchema(IGM);
// Forward the indirect return values. We might have to reabstract the
// return value.
if (nativeResultSchema.requiresIndirect()) {
assert(origNativeSchema.requiresIndirect());
auto resultAddr = origParams.claimNext();
resultAddr = subIGF.Builder.CreateBitCast(
resultAddr, IGM.getStoragePointerType(origConv.getSILResultType()));
args.add(resultAddr);
} else if (origNativeSchema.requiresIndirect()) {
assert(!nativeResultSchema.requiresIndirect());
auto stackAddr = outResultTI.allocateStack(
subIGF, outConv.getSILResultType(), false, "return.temp");
resultValueAddr = stackAddr.getAddress();
auto resultAddr = subIGF.Builder.CreateBitCast(
resultValueAddr,
IGM.getStoragePointerType(origConv.getSILResultType()));
args.add(resultAddr.getAddress());
}
for (auto resultType : origConv.getIndirectSILResultTypes()) {
auto addr = origParams.claimNext();
addr = subIGF.Builder.CreateBitCast(
addr, IGM.getStoragePointerType(resultType));
args.add(addr);
}
// Reemit the parameters as unsubstituted.
for (unsigned i = 0; i < outType->getParameters().size(); ++i) {
auto origParamInfo = origType->getParameters()[i];
auto &ti = IGM.getTypeInfoForLowered(origParamInfo.getType());
auto schema = ti.getSchema();
auto origParamSILType = IGM.silConv.getSILType(origParamInfo);
// Forward the address of indirect value params.
auto &nativeSchemaOrigParam = ti.nativeParameterValueSchema(IGM);
bool isIndirectParam = origConv.isSILIndirect(origParamInfo);
if (!isIndirectParam && nativeSchemaOrigParam.requiresIndirect()) {
auto addr = origParams.claimNext();
if (addr->getType() != ti.getStorageType()->getPointerTo())
addr = subIGF.Builder.CreateBitCast(addr,
ti.getStorageType()->getPointerTo());
args.add(addr);
continue;
}
auto outTypeParamInfo = outType->getParameters()[i];
// Indirect parameters need no mapping through the native calling
// convention.
if (isIndirectParam) {
emitApplyArgument(subIGF, origParamInfo, outTypeParamInfo, origParams,
args);
continue;
}
// Map from the native calling convention into the explosion schema.
auto outTypeParamSILType = IGM.silConv.getSILType(origParamInfo);
auto &nativeSchemaOutTypeParam =
IGM.getTypeInfo(outTypeParamSILType).nativeParameterValueSchema(IGM);
Explosion nativeParam;
origParams.transferInto(nativeParam, nativeSchemaOutTypeParam.size());
bindPolymorphicParameter(subIGF, origType, substType, nativeParam, i);
Explosion nonNativeParam = nativeSchemaOutTypeParam.mapFromNative(
subIGF.IGM, subIGF, nativeParam, outTypeParamSILType);
assert(nativeParam.empty());
// Emit unsubstituted argument for call.
Explosion nonNativeApplyArg;
emitApplyArgument(subIGF, origParamInfo, outTypeParamInfo, nonNativeParam,
nonNativeApplyArg);
assert(nonNativeParam.empty());
// Map back from the explosion scheme to the native calling convention for
// the call.
Explosion nativeApplyArg = nativeSchemaOrigParam.mapIntoNative(
subIGF.IGM, subIGF, nonNativeApplyArg, origParamSILType);
assert(nonNativeApplyArg.empty());
nativeApplyArg.transferInto(args, nativeApplyArg.size());
}
}
struct AddressToDeallocate {
SILType Type;
const TypeInfo &TI;
StackAddress Addr;
};
SmallVector<AddressToDeallocate, 4> addressesToDeallocate;
bool dependsOnContextLifetime = false;
bool consumesContext;
bool needsAllocas = false;
switch (outType->getCalleeConvention()) {
case ParameterConvention::Direct_Owned:
consumesContext = true;
break;
case ParameterConvention::Direct_Unowned:
case ParameterConvention::Direct_Guaranteed:
consumesContext = false;
break;
case ParameterConvention::Indirect_Inout:
case ParameterConvention::Indirect_InoutAliasable:
case ParameterConvention::Indirect_In:
case ParameterConvention::Indirect_In_Constant:
case ParameterConvention::Indirect_In_Guaranteed:
llvm_unreachable("indirect callables not supported");
}
// Lower the captured arguments in the original function's generic context.
GenericContextScope scope(IGM, origType->getGenericSignature());
// This is where the context parameter appears.
llvm::Value *rawData = nullptr;
Address data;
unsigned nextCapturedField = 0;
if (!layout) {
rawData = origParams.claimNext();
} else if (!layout->isKnownEmpty()) {
rawData = origParams.claimNext();
data = layout->emitCastTo(subIGF, rawData);
// Restore type metadata bindings, if we have them.
if (layout->hasBindings()) {
auto bindingLayout = layout->getElement(nextCapturedField++);
// The bindings should be fixed-layout inside the object, so we can
// pass None here. If they weren't, we'd have a chicken-egg problem.
auto bindingsAddr = bindingLayout.project(subIGF, data, /*offsets*/ None);
layout->getBindings().restore(subIGF, bindingsAddr);
}
// There's still a placeholder to claim if the target type is thick
// or there's an error result.
} else if (outType->getRepresentation()==SILFunctionTypeRepresentation::Thick
|| outType->hasErrorResult()) {
llvm::Value *contextPtr = origParams.claimNext(); (void)contextPtr;
assert(contextPtr->getType() == IGM.RefCountedPtrTy);
}
Explosion polyArgs;
// Emit the polymorphic arguments.
assert((subs.empty() != hasPolymorphicParameters(origType) ||
(subs.empty() && origType->getRepresentation() ==
SILFunctionTypeRepresentation::WitnessMethod))
&& "should have substitutions iff original function is generic");
WitnessMetadata witnessMetadata;
// If we have a layout we might have to bind polymorphic arguments from the
// captured arguments which we will do later. Otherwise, we have to
// potentially bind polymorphic arguments from the context if it was a
// partially applied argument.
bool hasPolymorphicParams = hasPolymorphicParameters(origType);
if (!layout && hasPolymorphicParams) {
assert(conventions.size() == 1);
// We could have either partially applied an argument from the function
// signature or otherwise we could have a closure context to forward. We only
// care for the former for the purpose of reconstructing polymorphic
// parameters from regular arguments.
if (!calleeHasContext) {
unsigned paramI =
findSinglePartiallyAppliedParameterIndexIgnoringEmptyTypes(
subIGF, substType, outType);
auto paramInfo = substType->getParameters()[paramI];
auto &ti = IGM.getTypeInfoForLowered(paramInfo.getType());
Explosion param;
param.add(subIGF.Builder.CreateBitCast(rawData, ti.getStorageType()));
bindPolymorphicParameter(subIGF, origType, substType, param, paramI);
(void)param.claimAll();
}
SubstitutionMap subMap;
if (auto genericSig = origType->getGenericSignature())
subMap = genericSig->getSubstitutionMap(subs);
emitPolymorphicArguments(subIGF, origType, subMap,
&witnessMetadata, polyArgs);
}
auto haveContextArgument =
calleeHasContext || hasSelfContextParameter(origType);
// Witness method calls expect self, followed by the self type followed by,
// the witness table at the end of the parameter list. But polymorphic
// arguments come before this.
bool isWitnessMethodCallee = origType->getRepresentation() ==
SILFunctionTypeRepresentation::WitnessMethod;
Explosion witnessMethodSelfValue;
// If there's a data pointer required, but it's a swift-retainable
// value being passed as the context, just forward it down.
if (!layout) {
assert(conventions.size() == 1);
// We need to retain the parameter if:
// - we received at +0 (either) and are passing as owned
// - we received as unowned and are passing as guaranteed
auto argConvention = conventions[nextCapturedField++];
switch (argConvention) {
case ParameterConvention::Indirect_In:
case ParameterConvention::Indirect_In_Constant:
case ParameterConvention::Direct_Owned:
if (!consumesContext) subIGF.emitNativeStrongRetain(rawData, subIGF.getDefaultAtomicity());
break;
case ParameterConvention::Indirect_In_Guaranteed:
case ParameterConvention::Direct_Guaranteed:
dependsOnContextLifetime = true;
if (outType->getCalleeConvention() ==
ParameterConvention::Direct_Unowned) {
subIGF.emitNativeStrongRetain(rawData, subIGF.getDefaultAtomicity());
consumesContext = true;
}
break;
case ParameterConvention::Direct_Unowned:
// Make sure we release later if we received at +1.
if (consumesContext)
dependsOnContextLifetime = true;
break;
case ParameterConvention::Indirect_Inout:
case ParameterConvention::Indirect_InoutAliasable:
llvm_unreachable("should never happen!");
}
// FIXME: The naming and documentation here isn't ideal. This
// parameter is always present which is evident since we always
// grab a type to cast to, but sometimes after the polymorphic
// arguments. This is just following the lead of existing (and not
// terribly easy to follow) code.
// If there is a context argument, it comes after the polymorphic
// arguments.
auto argIndex = args.size();
if (haveContextArgument)
argIndex += polyArgs.size();
llvm::Type *expectedArgTy = origSig.getType()->getParamType(argIndex);
llvm::Value *argValue;
if (isIndirectFormalParameter(argConvention)) {
// We can use rawData's type for the alloca because it is a swift
// retainable value. Defensively, give it that type. We can't use the
// expectedArgType because it might be a generic parameter and therefore
// have opaque storage.
auto RetainableValue = rawData;
if (RetainableValue->getType() != subIGF.IGM.RefCountedPtrTy)
RetainableValue = subIGF.Builder.CreateBitCast(
RetainableValue, subIGF.IGM.RefCountedPtrTy);
auto temporary = subIGF.createAlloca(RetainableValue->getType(),
subIGF.IGM.getPointerAlignment(),
"partial-apply.context");
subIGF.Builder.CreateStore(RetainableValue, temporary);
argValue = temporary.getAddress();
argValue = subIGF.Builder.CreateBitCast(argValue, expectedArgTy);
} else {
argValue = subIGF.Builder.CreateBitCast(rawData, expectedArgTy);
}
args.add(argValue);
// If there's a data pointer required, grab it and load out the
// extra, previously-curried parameters.
} else {
unsigned origParamI = outType->getParameters().size();
assert(layout->getElements().size() == conventions.size()
&& "conventions don't match context layout");
// Calculate non-fixed field offsets.
HeapNonFixedOffsets offsets(subIGF, *layout);
// Perform the loads.
for (unsigned n = layout->getElements().size();
nextCapturedField < n;
++nextCapturedField) {
auto &fieldLayout = layout->getElement(nextCapturedField);
auto &fieldTy = layout->getElementTypes()[nextCapturedField];
auto fieldConvention = conventions[nextCapturedField];
Address fieldAddr = fieldLayout.project(subIGF, data, offsets);
auto &fieldTI = fieldLayout.getType();
auto fieldSchema = fieldTI.getSchema();
Explosion param;
switch (fieldConvention) {
case ParameterConvention::Indirect_In:
case ParameterConvention::Indirect_In_Constant: {
// The +1 argument is passed indirectly, so we need to copy into a
// temporary.
needsAllocas = true;
auto stackAddr = fieldTI.allocateStack(subIGF, fieldTy, false, "arg.temp");
auto addressPointer = stackAddr.getAddress().getAddress();
fieldTI.initializeWithCopy(subIGF, stackAddr.getAddress(), fieldAddr, fieldTy);
param.add(addressPointer);
// Remember to deallocate later.
addressesToDeallocate.push_back(
AddressToDeallocate{fieldTy, fieldTI, stackAddr});
break;
}
case ParameterConvention::Indirect_In_Guaranteed:
// The argument is +0, so we can use the address of the param in
// the context directly.
param.add(fieldAddr.getAddress());
dependsOnContextLifetime = true;
break;
case ParameterConvention::Indirect_Inout:
case ParameterConvention::Indirect_InoutAliasable:
// Load the address of the inout parameter.
cast<LoadableTypeInfo>(fieldTI).loadAsCopy(subIGF, fieldAddr, param);
break;
case ParameterConvention::Direct_Guaranteed:
case ParameterConvention::Direct_Unowned:
// If the type is nontrivial, keep the context alive since the field
// depends on the context to not be deallocated.
if (!fieldTI.isPOD(ResilienceExpansion::Maximal))
dependsOnContextLifetime = true;
// Load these parameters directly. We can "take" since the parameter is
// +0. This can happen since the context will keep the parameter alive.
cast<LoadableTypeInfo>(fieldTI).loadAsTake(subIGF, fieldAddr, param);
break;
case ParameterConvention::Direct_Owned:
// Copy the value out at +1.
cast<LoadableTypeInfo>(fieldTI).loadAsCopy(subIGF, fieldAddr, param);
break;
}
// Reemit the capture params as unsubstituted.
// Skip empty parameters.
while (origParamI < origType->getParameters().size()) {
if (!isABIIgnoredParameterWithoutStorage(IGM, subIGF, substType,
origParamI))
break;
origParamI++;
}
if (origParamI < origType->getParameters().size()) {
Explosion origParam;
auto origParamInfo = origType->getParameters()[origParamI];
if (hasPolymorphicParams)
bindPolymorphicParameter(subIGF, origType, substType, param,
origParamI);
emitApplyArgument(subIGF, origParamInfo,
substType->getParameters()[origParamI],
param, origParam);
bool isWitnessMethodCalleeSelf = (isWitnessMethodCallee &&
origParamI + 1 == origType->getParameters().size());
needsAllocas |= addNativeArgument(
subIGF, origParam, origParamInfo,
isWitnessMethodCalleeSelf ? witnessMethodSelfValue : args);
++origParamI;
} else {
args.add(param.claimAll());
}
}
// If the parameters can live independent of the context, release it now
// so we can tail call. The safety of this assumes that neither this release
// nor any of the loads can throw.
if (consumesContext && !dependsOnContextLifetime && rawData)
subIGF.emitNativeStrongRelease(rawData, subIGF.getDefaultAtomicity());
// Now that we have bound generic parameters from the captured arguments
// emit the polymorphic arguments.
if (hasPolymorphicParameters(origType)) {
SubstitutionMap subMap;
if (auto genericSig = origType->getGenericSignature())
subMap = genericSig->getSubstitutionMap(subs);
emitPolymorphicArguments(subIGF, origType, subMap,
&witnessMetadata, polyArgs);
}
}
// Derive the callee function pointer.
auto fnTy = origSig.getType()->getPointerTo();
FunctionPointer fnPtr = [&] {
// If we found a function pointer statically, great.
if (staticFnPtr) {
assert(staticFnPtr->getType() == fnTy &&
"static function type mismatch?!");
Signature sig(cast<llvm::FunctionType>(fnTy->getElementType()),
staticFnPtr->getAttributes(),
staticFnPtr->getCallingConv());
return FunctionPointer::forDirect(staticFnPtr, sig);
}
// Otherwise, it was the last thing we added to the layout.
// The dynamic function pointer is packed "last" into the context,
// and we pulled it out as an argument. Just pop it off.
auto fnPtr = args.takeLast();
// It comes out of the context as an i8*. Cast to the function type.
fnPtr = subIGF.Builder.CreateBitCast(fnPtr, fnTy);
return FunctionPointer(fnPtr, origSig);
}();
// Derive the context argument if needed. This is either:
// - the saved context argument, in which case it was the last
// thing we added to the layout other than a possible non-static
// function pointer (which we already popped off of 'args'); or
// - 'self', in which case it was the last formal argument.
// In either case, it's the last thing in 'args'.
llvm::Value *fnContext = nullptr;
if (haveContextArgument)
fnContext = args.takeLast();
polyArgs.transferInto(args, polyArgs.size());
// If we have a witness method call, the inner context is the
// witness table. Metadata for Self is derived inside the partial
// application thunk and doesn't need to be stored in the outer
// context.
if (isWitnessMethodCallee) {
assert(fnContext->getType() == IGM.Int8PtrTy);
llvm::Value *wtable = subIGF.Builder.CreateBitCast(
fnContext, IGM.WitnessTablePtrTy);
assert(wtable->getType() == IGM.WitnessTablePtrTy);
witnessMetadata.SelfWitnessTable = wtable;
// Okay, this is where the callee context goes.
} else if (fnContext) {
args.add(fnContext);
// Pass a placeholder for thin function calls.
} else if (origType->hasErrorResult()) {
args.add(llvm::UndefValue::get(IGM.RefCountedPtrTy));
}
// Add the witness methods self argument before the error parameter after the
// polymorphic arguments.
if (isWitnessMethodCallee)
witnessMethodSelfValue.transferInto(args, witnessMethodSelfValue.size());
// Pass down the error result.
if (origType->hasErrorResult()) {
llvm::Value *errorResultPtr = origParams.claimNext();
args.add(errorResultPtr);
}
assert(origParams.empty());
if (isWitnessMethodCallee) {
assert(witnessMetadata.SelfMetadata->getType() == IGM.TypeMetadataPtrTy);
args.add(witnessMetadata.SelfMetadata);
assert(witnessMetadata.SelfWitnessTable->getType() == IGM.WitnessTablePtrTy);
args.add(witnessMetadata.SelfWitnessTable);
}
llvm::CallInst *call = subIGF.Builder.CreateCall(fnPtr, args.claimAll());
if (addressesToDeallocate.empty() && !needsAllocas &&
(!consumesContext || !dependsOnContextLifetime))
call->setTailCall();
// Deallocate everything we allocated above.
// FIXME: exceptions?
for (auto &entry : addressesToDeallocate) {
entry.TI.deallocateStack(subIGF, entry.Addr, entry.Type);
}
// If the parameters depended on the context, consume the context now.
if (rawData && consumesContext && dependsOnContextLifetime)
subIGF.emitNativeStrongRelease(rawData, subIGF.getDefaultAtomicity());
// Reabstract the result value as substituted.
SILFunctionConventions origConv(origType, IGM.getSILModule());
auto &outResultTI = IGM.getTypeInfo(outConv.getSILResultType());
auto &nativeResultSchema = outResultTI.nativeReturnValueSchema(IGM);
if (call->getType()->isVoidTy()) {
if (!resultValueAddr.isValid())
subIGF.Builder.CreateRetVoid();
else {
// Okay, we have called a function that expects an indirect return type
// but the partially applied return type is direct.
assert(!nativeResultSchema.requiresIndirect());
Explosion loadedResult;
cast<LoadableTypeInfo>(outResultTI)
.loadAsTake(subIGF, resultValueAddr, loadedResult);
Explosion nativeResult = nativeResultSchema.mapIntoNative(
IGM, subIGF, loadedResult, outConv.getSILResultType());
outResultTI.deallocateStack(subIGF, resultValueAddr,
outConv.getSILResultType());
if (nativeResult.size() == 1)
subIGF.Builder.CreateRet(nativeResult.claimNext());
else {
llvm::Value *nativeAgg =
llvm::UndefValue::get(nativeResultSchema.getExpandedType(IGM));
for (unsigned i = 0, e = nativeResult.size(); i != e; ++i) {
auto *elt = nativeResult.claimNext();
nativeAgg = subIGF.Builder.CreateInsertValue(nativeAgg, elt, i);
}
subIGF.Builder.CreateRet(nativeAgg);
}
}
} else {
llvm::Value *callResult = call;
// If the result type is dependent on a type parameter we might have to
// cast to the result type - it could be substituted.
if (origConv.getSILResultType().hasTypeParameter()) {
auto ResType = fwd->getReturnType();
callResult = subIGF.Builder.CreateBitCast(callResult, ResType);
}
subIGF.Builder.CreateRet(callResult);
}
return fwd;
}
/// Emit a partial application thunk for a function pointer applied to a partial
/// set of argument values.
void irgen::emitFunctionPartialApplication(IRGenFunction &IGF,
SILFunction &SILFn,
const FunctionPointer &fn,
llvm::Value *fnContext,
Explosion &args,
ArrayRef<SILParameterInfo> params,
SubstitutionList subs,
CanSILFunctionType origType,
CanSILFunctionType substType,
CanSILFunctionType outType,
Explosion &out) {
// If we have a single Swift-refcounted context value, we can adopt it
// directly as our closure context without creating a box and thunk.
enum HasSingleSwiftRefcountedContext { Maybe, Yes, No, Thunkable }
hasSingleSwiftRefcountedContext = Maybe;
Optional<ParameterConvention> singleRefcountedConvention;
SmallVector<const TypeInfo *, 4> argTypeInfos;
SmallVector<SILType, 4> argValTypes;
SmallVector<ParameterConvention, 4> argConventions;
llvm::Value *fnPtr = fn.getPointer();
// Reserve space for polymorphic bindings.
SubstitutionMap subMap;
if (auto genericSig = origType->getGenericSignature())
subMap = genericSig->getSubstitutionMap(subs);
auto bindings = NecessaryBindings::forFunctionInvocations(IGF.IGM,
origType, subMap);
if (!bindings.empty()) {
hasSingleSwiftRefcountedContext = No;
auto bindingsSize = bindings.getBufferSize(IGF.IGM);
auto &bindingsTI = IGF.IGM.getOpaqueStorageTypeInfo(bindingsSize,
IGF.IGM.getPointerAlignment());
argValTypes.push_back(SILType());
argTypeInfos.push_back(&bindingsTI);
argConventions.push_back(ParameterConvention::Direct_Unowned);
}
// Collect the type infos for the context parameters.
for (auto param : params) {
SILType argType = IGF.IGM.silConv.getSILType(param);
auto argLoweringTy =
getArgumentLoweringType(argType.getSwiftRValueType(), param);
auto &ti = IGF.getTypeInfoForLowered(argLoweringTy);
// Empty values don't matter.
auto schema = ti.getSchema();
if (schema.size() == 0 && !param.isFormalIndirect())
continue;
argValTypes.push_back(argType);
argConventions.push_back(param.getConvention());
argTypeInfos.push_back(&ti);
// Update the single-swift-refcounted check, unless we already ruled that
// out.
if (hasSingleSwiftRefcountedContext == No)
continue;
// Adding nonempty values when we already have a single refcounted pointer
// means we don't have a single value anymore.
if (hasSingleSwiftRefcountedContext != Maybe) {
hasSingleSwiftRefcountedContext = No;
continue;
}
if (ti.isSingleSwiftRetainablePointer(ResilienceExpansion::Maximal)) {
hasSingleSwiftRefcountedContext = Yes;
singleRefcountedConvention = param.getConvention();
} else {
hasSingleSwiftRefcountedContext = No;
}
}
// We can't just bitcast if there's an error parameter to forward.
// This is an unfortunate restriction arising from the fact that a
// thin throwing function will have the signature:
// %result (%arg*, %context*, %error*)
// but the output signature needs to be
// %result (%context*, %error*)
//
// 'swifterror' fixes this physically, but there's still a risk of
// miscompiles because the LLVM optimizer may forward arguments
// positionally without considering 'swifterror'.
//
// Note, however, that we will override this decision below if the
// only thing we have to forward is already a context pointer.
// That's fine.
//
// The proper long-term fix is that closure functions should be
// emitted with a convention that takes the closure box as the
// context parameter. When we do that, all of this code will
// disappear.
if (hasSingleSwiftRefcountedContext == Yes &&
origType->hasErrorResult()) {
hasSingleSwiftRefcountedContext = Thunkable;
}
// If the function pointer is a witness method call, include the witness
// table in the context.
if (origType->getRepresentation() ==
SILFunctionTypeRepresentation::WitnessMethod) {
llvm::Value *wtable = fnContext;
assert(wtable->getType() == IGF.IGM.WitnessTablePtrTy);
// TheRawPointerType lowers as i8*, not i8**.
args.add(IGF.Builder.CreateBitCast(wtable, IGF.IGM.Int8PtrTy));
argValTypes.push_back(SILType::getRawPointerType(IGF.IGM.Context));
argTypeInfos.push_back(
&IGF.getTypeInfoForLowered(IGF.IGM.Context.TheRawPointerType));
argConventions.push_back(ParameterConvention::Direct_Unowned);
hasSingleSwiftRefcountedContext = No;
// Otherwise, we might have a reference-counted context pointer.
} else if (fnContext) {
args.add(fnContext);
argValTypes.push_back(SILType::getNativeObjectType(IGF.IGM.Context));
argConventions.push_back(origType->getCalleeConvention());
argTypeInfos.push_back(
&IGF.getTypeInfoForLowered(IGF.IGM.Context.TheNativeObjectType));
// If this is the only context argument we end up with, we can just share
// it.
if (args.size() == 1) {
assert(bindings.empty());
hasSingleSwiftRefcountedContext = Yes;
singleRefcountedConvention = origType->getCalleeConvention();
}
}
// If we have a single refcounted pointer context (and no polymorphic args
// to capture), and the dest ownership semantics match the parameter's,
// skip building the box and thunk and just take the pointer as
// context.
// TODO: We can only do this and use swiftself if all our swiftcc emit the
// last parameter that fits into a register as swiftself.
// We should get this optimization back using the @convention(closure) whose
// box argument should just be swift self.
if (/* DISABLES CODE */ (false) &&
!origType->isPolymorphic() &&
hasSingleSwiftRefcountedContext == Yes &&
outType->getCalleeConvention() == *singleRefcountedConvention) {
assert(args.size() == 1);
fnPtr = IGF.Builder.CreateBitCast(fnPtr, IGF.IGM.Int8PtrTy);
out.add(fnPtr);
llvm::Value *ctx = args.claimNext();
ctx = IGF.Builder.CreateBitCast(ctx, IGF.IGM.RefCountedPtrTy);
out.add(ctx);
return;
}
// If the function pointer is dynamic, include it in the context.
auto staticFn = dyn_cast<llvm::Function>(fnPtr);
if (!staticFn) {
llvm::Value *fnRawPtr = IGF.Builder.CreateBitCast(fnPtr, IGF.IGM.Int8PtrTy);
args.add(fnRawPtr);
argValTypes.push_back(SILType::getRawPointerType(IGF.IGM.Context));
argTypeInfos.push_back(
&IGF.getTypeInfoForLowered(IGF.IGM.Context.TheRawPointerType));
argConventions.push_back(ParameterConvention::Direct_Unowned);
hasSingleSwiftRefcountedContext = No;
}
// If we only need to capture a single Swift-refcounted object, we
// still need to build a thunk, but we don't need to allocate anything.
if ((hasSingleSwiftRefcountedContext == Yes ||
hasSingleSwiftRefcountedContext == Thunkable) &&
*singleRefcountedConvention != ParameterConvention::Indirect_Inout &&
*singleRefcountedConvention !=
ParameterConvention::Indirect_InoutAliasable) {
assert(bindings.empty());
assert(args.size() == 1);
auto origSig = IGF.IGM.getSignature(origType);
llvm::Function *forwarder =
emitPartialApplicationForwarder(IGF.IGM, staticFn, fnContext != nullptr,
origSig, origType, substType,
outType, subs, nullptr, argConventions);
llvm::Value *forwarderValue =
IGF.Builder.CreateBitCast(forwarder, IGF.IGM.Int8PtrTy);
out.add(forwarderValue);
llvm::Value *ctx = args.claimNext();
if (isIndirectFormalParameter(*singleRefcountedConvention))
ctx = IGF.Builder.CreateLoad(ctx, IGF.IGM.getPointerAlignment());
ctx = IGF.Builder.CreateBitCast(ctx, IGF.IGM.RefCountedPtrTy);
out.add(ctx);
return;
}
// Store the context arguments on the heap.
assert(argValTypes.size() == argTypeInfos.size()
&& argTypeInfos.size() == argConventions.size()
&& "argument info lists out of sync");
HeapLayout layout(IGF.IGM, LayoutStrategy::Optimal, argValTypes, argTypeInfos,
/*typeToFill*/ nullptr,
std::move(bindings));
auto descriptor = IGF.IGM.getAddrOfCaptureDescriptor(SILFn, origType,
substType, subs,
layout);
llvm::Value *data;
if (args.empty() && layout.isKnownEmpty()) {
data = IGF.IGM.RefCountedNull;
} else {
// Allocate a new object.
HeapNonFixedOffsets offsets(IGF, layout);
data = IGF.emitUnmanagedAlloc(layout, "closure", descriptor, &offsets);
Address dataAddr = layout.emitCastTo(IGF, data);
unsigned i = 0;
// Store necessary bindings, if we have them.
if (layout.hasBindings()) {
auto &bindingsLayout = layout.getElement(i);
Address bindingsAddr = bindingsLayout.project(IGF, dataAddr, offsets);
layout.getBindings().save(IGF, bindingsAddr);
++i;
}
// Store the context arguments.
for (unsigned end = layout.getElements().size(); i < end; ++i) {
auto &fieldLayout = layout.getElement(i);
auto &fieldTy = layout.getElementTypes()[i];
Address fieldAddr = fieldLayout.project(IGF, dataAddr, offsets);
switch (argConventions[i]) {
// Take indirect value arguments out of memory.
case ParameterConvention::Indirect_In:
case ParameterConvention::Indirect_In_Constant:
case ParameterConvention::Indirect_In_Guaranteed: {
auto addr = fieldLayout.getType().getAddressForPointer(args.claimNext());
fieldLayout.getType().initializeWithTake(IGF, fieldAddr, addr, fieldTy);
break;
}
// Take direct value arguments and inout pointers by value.
case ParameterConvention::Direct_Unowned:
case ParameterConvention::Direct_Owned:
case ParameterConvention::Direct_Guaranteed:
case ParameterConvention::Indirect_Inout:
case ParameterConvention::Indirect_InoutAliasable:
cast<LoadableTypeInfo>(fieldLayout.getType())
.initialize(IGF, args, fieldAddr);
break;
}
}
}
assert(args.empty() && "unused args in partial application?!");
// Create the forwarding stub.
auto origSig = IGF.IGM.getSignature(origType);
llvm::Function *forwarder = emitPartialApplicationForwarder(IGF.IGM,
staticFn,
fnContext != nullptr,
origSig,
origType,
substType,
outType,
subs,
&layout,
argConventions);
llvm::Value *forwarderValue = IGF.Builder.CreateBitCast(forwarder,
IGF.IGM.Int8PtrTy);
out.add(forwarderValue);
out.add(data);
}
/// Emit the block copy helper for a block.
static llvm::Function *emitBlockCopyHelper(IRGenModule &IGM,
CanSILBlockStorageType blockTy,
const BlockStorageTypeInfo &blockTL){
// See if we've produced a block copy helper for this type before.
// TODO
// Create the helper.
llvm::Type *args[] = {
blockTL.getStorageType()->getPointerTo(),
blockTL.getStorageType()->getPointerTo(),
};
auto copyTy = llvm::FunctionType::get(IGM.VoidTy, args, /*vararg*/ false);
// TODO: Give these predictable mangled names and shared linkage.
auto func = llvm::Function::Create(copyTy, llvm::GlobalValue::InternalLinkage,
"block_copy_helper",
IGM.getModule());
func->setAttributes(IGM.constructInitialAttributes());
IRGenFunction IGF(IGM, func);
if (IGM.DebugInfo)
IGM.DebugInfo->emitArtificialFunction(IGF, func);
// Copy the captures from the source to the destination.
Explosion params = IGF.collectParameters();
auto dest = Address(params.claimNext(), blockTL.getFixedAlignment());
auto src = Address(params.claimNext(), blockTL.getFixedAlignment());
auto destCapture = blockTL.projectCapture(IGF, dest);
auto srcCapture = blockTL.projectCapture(IGF, src);
auto &captureTL = IGM.getTypeInfoForLowered(blockTy->getCaptureType());
captureTL.initializeWithCopy(IGF, destCapture, srcCapture,
blockTy->getCaptureAddressType());
IGF.Builder.CreateRetVoid();
return func;
}
/// Emit the block copy helper for a block.
static llvm::Function *emitBlockDisposeHelper(IRGenModule &IGM,
CanSILBlockStorageType blockTy,
const BlockStorageTypeInfo &blockTL){
// See if we've produced a block destroy helper for this type before.
// TODO
// Create the helper.
auto destroyTy = llvm::FunctionType::get(IGM.VoidTy,
blockTL.getStorageType()->getPointerTo(),
/*vararg*/ false);
// TODO: Give these predictable mangled names and shared linkage.
auto func = llvm::Function::Create(destroyTy,
llvm::GlobalValue::InternalLinkage,
"block_destroy_helper",
IGM.getModule());
func->setAttributes(IGM.constructInitialAttributes());
IRGenFunction IGF(IGM, func);
assert(!func->hasFnAttribute(llvm::Attribute::SanitizeThread));
if (IGM.DebugInfo)
IGM.DebugInfo->emitArtificialFunction(IGF, func);
// Destroy the captures.
Explosion params = IGF.collectParameters();
auto storage = Address(params.claimNext(), blockTL.getFixedAlignment());
auto capture = blockTL.projectCapture(IGF, storage);
auto &captureTL = IGM.getTypeInfoForLowered(blockTy->getCaptureType());
captureTL.destroy(IGF, capture, blockTy->getCaptureAddressType());
IGF.Builder.CreateRetVoid();
return func;
}
/// Emit the block header into a block storage slot.
void irgen::emitBlockHeader(IRGenFunction &IGF,
Address storage,
CanSILBlockStorageType blockTy,
llvm::Constant *invokeFunction,
CanSILFunctionType invokeTy,
ForeignFunctionInfo foreignInfo) {
auto &storageTL
= IGF.getTypeInfoForLowered(blockTy).as<BlockStorageTypeInfo>();
Address headerAddr = storageTL.projectBlockHeader(IGF, storage);
//
// Initialize the "isa" pointer, which is _NSConcreteStackBlock.
auto NSConcreteStackBlock =
IGF.IGM.getModule()->getOrInsertGlobal("_NSConcreteStackBlock",
IGF.IGM.ObjCClassStructTy);
if (IGF.IGM.useDllStorage())
cast<llvm::GlobalVariable>(NSConcreteStackBlock)
->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
//
// Set the flags.
// - HAS_COPY_DISPOSE unless the capture type is POD
uint32_t flags = 0;
auto &captureTL
= IGF.getTypeInfoForLowered(blockTy->getCaptureType());
bool isPOD = captureTL.isPOD(ResilienceExpansion::Maximal);
if (!isPOD)
flags |= 1 << 25;
// - HAS_STRET, if the invoke function is sret
assert(foreignInfo.ClangInfo);
if (foreignInfo.ClangInfo->getReturnInfo().isIndirect())
flags |= 1 << 29;
// - HAS_SIGNATURE
flags |= 1 << 30;
auto flagsVal = llvm::ConstantInt::get(IGF.IGM.Int32Ty, flags);
// Collect the reserved and invoke pointer fields.
auto reserved = llvm::ConstantInt::get(IGF.IGM.Int32Ty, 0);
auto invokeVal = llvm::ConstantExpr::getBitCast(invokeFunction,
IGF.IGM.FunctionPtrTy);
// Build the block descriptor.
ConstantInitBuilder builder(IGF.IGM);
auto descriptorFields = builder.beginStruct();
descriptorFields.addInt(IGF.IGM.IntPtrTy, 0);
descriptorFields.addInt(IGF.IGM.IntPtrTy,
storageTL.getFixedSize().getValue());
if (!isPOD) {
// Define the copy and dispose helpers.
descriptorFields.add(emitBlockCopyHelper(IGF.IGM, blockTy, storageTL));
descriptorFields.add(emitBlockDisposeHelper(IGF.IGM, blockTy, storageTL));
}
// Build the descriptor signature.
descriptorFields.add(getBlockTypeExtendedEncoding(IGF.IGM, invokeTy));
// Create the descriptor.
auto descriptor =
descriptorFields.finishAndCreateGlobal("block_descriptor",
IGF.IGM.getPointerAlignment(),
/*constant*/ true);
auto descriptorVal = llvm::ConstantExpr::getBitCast(descriptor,
IGF.IGM.Int8PtrTy);
//
// Store the block header literal.
llvm::Constant *blockFields[] = {
NSConcreteStackBlock,
flagsVal,
reserved,
invokeVal,
descriptorVal,
};
auto blockHeader = llvm::ConstantStruct::get(IGF.IGM.ObjCBlockStructTy,
blockFields);
IGF.Builder.CreateStore(blockHeader, headerAddr);
}
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