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2ba7090fe8
This is essentially a long-belated follow-up to Arnold's #12606. The key observation here is that the enum-tag-single-payload witnesses are strictly more powerful than the XI witnesses: you can simulate the XI witnesses by using an extra case count that's <= the XI count. Of course the result is less efficient than the XI witnesses, but that's less important than overall code size, and we can work on fast-paths for that. The extra inhabitant count is stored in a 32-bit field (always present) following the ValueWitnessFlags, which now occupy a fixed 32 bits. This inflates non-XI VWTs on 32-bit targets by a word, but the net effect on XI VWTs is to shrink them by two words, which is likely to be the more important change. Also, being able to access the XI count directly should be a nice win.
961 lines
38 KiB
C++
961 lines
38 KiB
C++
//===--- GenStruct.cpp - Swift IR Generation For 'struct' Types -----------===//
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//
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// This source file is part of the Swift.org open source project
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//
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// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
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// Licensed under Apache License v2.0 with Runtime Library Exception
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//
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// See https://swift.org/LICENSE.txt for license information
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// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements IR generation for struct types.
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//
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//===----------------------------------------------------------------------===//
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#include "GenStruct.h"
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#include "swift/AST/Types.h"
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#include "swift/AST/Decl.h"
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#include "swift/AST/IRGenOptions.h"
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#include "swift/AST/Pattern.h"
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#include "swift/AST/SubstitutionMap.h"
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#include "swift/IRGen/Linking.h"
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#include "swift/SIL/SILModule.h"
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#include "llvm/IR/DerivedTypes.h"
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#include "llvm/IR/Function.h"
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#include "clang/AST/ASTContext.h"
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#include "clang/AST/Decl.h"
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#include "clang/AST/RecordLayout.h"
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#include "clang/CodeGen/SwiftCallingConv.h"
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#include "GenMeta.h"
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#include "GenRecord.h"
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#include "GenType.h"
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#include "IRGenFunction.h"
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#include "IRGenModule.h"
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#include "IndirectTypeInfo.h"
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#include "MemberAccessStrategy.h"
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#include "NonFixedTypeInfo.h"
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#include "ResilientTypeInfo.h"
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#include "StructMetadataVisitor.h"
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#include "MetadataLayout.h"
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#pragma clang diagnostic ignored "-Winconsistent-missing-override"
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using namespace swift;
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using namespace irgen;
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/// The kinds of TypeInfos implementing struct types.
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enum class StructTypeInfoKind {
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LoadableStructTypeInfo,
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FixedStructTypeInfo,
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ClangRecordTypeInfo,
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NonFixedStructTypeInfo,
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ResilientStructTypeInfo
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};
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static StructTypeInfoKind getStructTypeInfoKind(const TypeInfo &type) {
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return (StructTypeInfoKind) type.getSubclassKind();
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}
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namespace {
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class StructFieldInfo : public RecordField<StructFieldInfo> {
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public:
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StructFieldInfo(VarDecl *field, const TypeInfo &type)
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: RecordField(type), Field(field) {}
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/// The field.
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VarDecl * const Field;
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StringRef getFieldName() const {
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return Field->getName().str();
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}
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SILType getType(IRGenModule &IGM, SILType T) const {
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return T.getFieldType(Field, IGM.getSILModule());
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}
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};
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/// A field-info implementation for fields of Clang types.
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class ClangFieldInfo : public RecordField<ClangFieldInfo> {
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public:
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ClangFieldInfo(VarDecl *swiftField, const ElementLayout &layout,
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unsigned explosionBegin, unsigned explosionEnd)
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: RecordField(layout, explosionBegin, explosionEnd),
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Field(swiftField) {}
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VarDecl * const Field;
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StringRef getFieldName() const {
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if (Field) return Field->getName().str();
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return "<unimported>";
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}
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SILType getType(IRGenModule &IGM, SILType T) const {
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if (Field)
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return T.getFieldType(Field, IGM.getSILModule());
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// The Swift-field-less cases use opaque storage, which is
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// guaranteed to ignore the type passed to it.
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return {};
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}
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};
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/// A common base class for structs.
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template <class Impl, class Base, class FieldInfoType = StructFieldInfo>
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class StructTypeInfoBase :
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public RecordTypeInfo<Impl, Base, FieldInfoType> {
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using super = RecordTypeInfo<Impl, Base, FieldInfoType>;
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protected:
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template <class... As>
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StructTypeInfoBase(StructTypeInfoKind kind, As &&...args)
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: super(std::forward<As>(args)...) {
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super::setSubclassKind((unsigned) kind);
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}
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using super::asImpl;
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public:
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const FieldInfoType &getFieldInfo(VarDecl *field) const {
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// FIXME: cache the physical field index in the VarDecl.
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for (auto &fieldInfo : asImpl().getFields()) {
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if (fieldInfo.Field == field)
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return fieldInfo;
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}
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llvm_unreachable("field not in struct?");
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}
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/// Given a full struct explosion, project out a single field.
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void projectFieldFromExplosion(IRGenFunction &IGF,
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Explosion &in,
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VarDecl *field,
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Explosion &out) const {
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auto &fieldInfo = getFieldInfo(field);
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// If the field requires no storage, there's nothing to do.
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if (fieldInfo.isEmpty())
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return;
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// Otherwise, project from the base.
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auto fieldRange = fieldInfo.getProjectionRange();
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auto elements = in.getRange(fieldRange.first, fieldRange.second);
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out.add(elements);
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}
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/// Given the address of a struct value, project out the address of a
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/// single field.
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Address projectFieldAddress(IRGenFunction &IGF,
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Address addr,
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SILType T,
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const FieldInfoType &field) const {
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return asImpl().projectFieldAddress(IGF, addr, T, field.Field);
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}
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/// Given the address of a struct value, project out the address of a
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/// single field.
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Address projectFieldAddress(IRGenFunction &IGF,
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Address addr,
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SILType T,
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VarDecl *field) const {
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auto &fieldInfo = getFieldInfo(field);
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if (fieldInfo.isEmpty())
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return fieldInfo.getTypeInfo().getUndefAddress();
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auto offsets = asImpl().getNonFixedOffsets(IGF, T);
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return fieldInfo.projectAddress(IGF, addr, offsets);
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}
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/// Return the constant offset of a field as a Int32Ty, or nullptr if the
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/// field is not at a fixed offset.
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llvm::Constant *getConstantFieldOffset(IRGenModule &IGM,
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VarDecl *field) const {
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auto &fieldInfo = getFieldInfo(field);
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if (fieldInfo.getKind() == ElementLayout::Kind::Fixed
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|| fieldInfo.getKind() == ElementLayout::Kind::Empty) {
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return llvm::ConstantInt::get(
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IGM.Int32Ty, fieldInfo.getFixedByteOffset().getValue());
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}
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return nullptr;
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}
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MemberAccessStrategy getFieldAccessStrategy(IRGenModule &IGM,
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SILType T, VarDecl *field) const {
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auto &fieldInfo = getFieldInfo(field);
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switch (fieldInfo.getKind()) {
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case ElementLayout::Kind::Fixed:
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case ElementLayout::Kind::Empty:
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return MemberAccessStrategy::getDirectFixed(
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fieldInfo.getFixedByteOffset());
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case ElementLayout::Kind::InitialNonFixedSize:
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return MemberAccessStrategy::getDirectFixed(Size(0));
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case ElementLayout::Kind::NonFixed:
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return asImpl().getNonFixedFieldAccessStrategy(IGM, T, fieldInfo);
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}
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llvm_unreachable("bad field layout kind");
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}
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unsigned getFieldIndex(IRGenModule &IGM, VarDecl *field) const {
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auto &fieldInfo = getFieldInfo(field);
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return fieldInfo.getStructIndex();
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}
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Optional<unsigned> getFieldIndexIfNotEmpty(IRGenModule &IGM,
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VarDecl *field) const {
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auto &fieldInfo = getFieldInfo(field);
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if (fieldInfo.isEmpty())
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return None;
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return fieldInfo.getStructIndex();
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}
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bool isSingleRetainablePointer(ResilienceExpansion expansion,
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ReferenceCounting *rc) const override {
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auto fields = asImpl().getFields();
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if (fields.size() != 1)
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return false;
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return fields[0].getTypeInfo().isSingleRetainablePointer(expansion, rc);
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}
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void verify(IRGenTypeVerifierFunction &IGF,
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llvm::Value *metadata,
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SILType structType) const override {
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// Check that constant field offsets we know match
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for (auto &field : asImpl().getFields()) {
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switch (field.getKind()) {
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case ElementLayout::Kind::Fixed: {
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// We know the offset at compile time. See whether there's also an
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// entry for this field in the field offset vector.
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class FindOffsetOfFieldOffsetVector
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: public StructMetadataScanner<FindOffsetOfFieldOffsetVector> {
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public:
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VarDecl *FieldToFind;
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Size AddressPoint = Size::invalid();
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Size FieldOffset = Size::invalid();
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FindOffsetOfFieldOffsetVector(IRGenModule &IGM, VarDecl *Field)
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: StructMetadataScanner<FindOffsetOfFieldOffsetVector>(
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IGM, cast<StructDecl>(Field->getDeclContext())),
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FieldToFind(Field) {}
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void noteAddressPoint() {
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AddressPoint = this->NextOffset;
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}
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void addFieldOffset(VarDecl *Field) {
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if (Field == FieldToFind) {
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FieldOffset = this->NextOffset;
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}
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StructMetadataScanner<
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FindOffsetOfFieldOffsetVector>::addFieldOffset(Field);
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}
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};
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FindOffsetOfFieldOffsetVector scanner(IGF.IGM, field.Field);
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scanner.layout();
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if (scanner.FieldOffset == Size::invalid()
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|| scanner.AddressPoint == Size::invalid())
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continue;
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// Load the offset from the field offset vector and ensure it matches
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// the compiler's idea of the offset.
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auto metadataBytes =
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IGF.Builder.CreateBitCast(metadata, IGF.IGM.Int8PtrTy);
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auto fieldOffsetPtr =
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IGF.Builder.CreateInBoundsGEP(metadataBytes,
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IGF.IGM.getSize(scanner.FieldOffset - scanner.AddressPoint));
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fieldOffsetPtr =
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IGF.Builder.CreateBitCast(fieldOffsetPtr,
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IGF.IGM.Int32Ty->getPointerTo());
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llvm::Value *fieldOffset =
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IGF.Builder.CreateLoad(fieldOffsetPtr, Alignment(4));
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fieldOffset = IGF.Builder.CreateZExtOrBitCast(fieldOffset,
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IGF.IGM.SizeTy);
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IGF.verifyValues(metadata, fieldOffset,
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IGF.IGM.getSize(field.getFixedByteOffset()),
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Twine("offset of struct field ") + field.getFieldName());
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break;
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}
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case ElementLayout::Kind::Empty:
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case ElementLayout::Kind::InitialNonFixedSize:
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case ElementLayout::Kind::NonFixed:
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continue;
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}
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}
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}
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};
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/// A type implementation for loadable record types imported from Clang.
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class ClangRecordTypeInfo final :
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public StructTypeInfoBase<ClangRecordTypeInfo, LoadableTypeInfo,
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ClangFieldInfo> {
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const clang::RecordDecl *ClangDecl;
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public:
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ClangRecordTypeInfo(ArrayRef<ClangFieldInfo> fields,
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unsigned explosionSize,
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llvm::Type *storageType, Size size,
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SpareBitVector &&spareBits, Alignment align,
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const clang::RecordDecl *clangDecl)
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: StructTypeInfoBase(StructTypeInfoKind::ClangRecordTypeInfo,
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fields, explosionSize,
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storageType, size, std::move(spareBits),
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align, IsPOD, IsFixedSize),
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ClangDecl(clangDecl)
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{
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}
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void initializeFromParams(IRGenFunction &IGF, Explosion ¶ms,
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Address addr, SILType T,
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bool isOutlined) const override {
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ClangRecordTypeInfo::initialize(IGF, params, addr, isOutlined);
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}
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void addToAggLowering(IRGenModule &IGM, SwiftAggLowering &lowering,
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Size offset) const override {
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lowering.addTypedData(ClangDecl, offset.asCharUnits());
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}
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llvm::NoneType getNonFixedOffsets(IRGenFunction &IGF) const {
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return None;
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}
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llvm::NoneType getNonFixedOffsets(IRGenFunction &IGF, SILType T) const {
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return None;
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}
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MemberAccessStrategy
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getNonFixedFieldAccessStrategy(IRGenModule &IGM, SILType T,
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const ClangFieldInfo &field) const {
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llvm_unreachable("non-fixed field in Clang type?");
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}
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};
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/// A type implementation for loadable struct types.
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class LoadableStructTypeInfo final
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: public StructTypeInfoBase<LoadableStructTypeInfo, LoadableTypeInfo> {
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public:
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LoadableStructTypeInfo(ArrayRef<StructFieldInfo> fields,
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unsigned explosionSize,
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llvm::Type *storageType, Size size,
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SpareBitVector &&spareBits,
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Alignment align, IsPOD_t isPOD,
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IsFixedSize_t alwaysFixedSize)
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: StructTypeInfoBase(StructTypeInfoKind::LoadableStructTypeInfo,
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fields, explosionSize,
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storageType, size, std::move(spareBits),
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align, isPOD, alwaysFixedSize)
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{}
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void addToAggLowering(IRGenModule &IGM, SwiftAggLowering &lowering,
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Size offset) const override {
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for (auto &field : getFields()) {
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auto fieldOffset = offset + field.getFixedByteOffset();
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cast<LoadableTypeInfo>(field.getTypeInfo())
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.addToAggLowering(IGM, lowering, fieldOffset);
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}
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}
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void initializeFromParams(IRGenFunction &IGF, Explosion ¶ms,
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Address addr, SILType T,
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bool isOutlined) const override {
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LoadableStructTypeInfo::initialize(IGF, params, addr, isOutlined);
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}
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llvm::NoneType getNonFixedOffsets(IRGenFunction &IGF) const {
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return None;
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}
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llvm::NoneType getNonFixedOffsets(IRGenFunction &IGF, SILType T) const {
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return None;
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}
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MemberAccessStrategy
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getNonFixedFieldAccessStrategy(IRGenModule &IGM, SILType T,
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const StructFieldInfo &field) const {
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llvm_unreachable("non-fixed field in loadable type?");
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}
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};
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/// A type implementation for non-loadable but fixed-size struct types.
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class FixedStructTypeInfo final
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: public StructTypeInfoBase<FixedStructTypeInfo,
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IndirectTypeInfo<FixedStructTypeInfo,
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FixedTypeInfo>> {
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public:
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// FIXME: Spare bits between struct members.
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FixedStructTypeInfo(ArrayRef<StructFieldInfo> fields, llvm::Type *T,
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Size size, SpareBitVector &&spareBits,
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Alignment align, IsPOD_t isPOD, IsBitwiseTakable_t isBT,
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IsFixedSize_t alwaysFixedSize)
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: StructTypeInfoBase(StructTypeInfoKind::FixedStructTypeInfo,
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fields, T, size, std::move(spareBits), align,
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isPOD, isBT, alwaysFixedSize)
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{}
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llvm::NoneType getNonFixedOffsets(IRGenFunction &IGF) const {
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return None;
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}
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llvm::NoneType getNonFixedOffsets(IRGenFunction &IGF, SILType T) const {
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return None;
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}
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MemberAccessStrategy
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getNonFixedFieldAccessStrategy(IRGenModule &IGM, SILType T,
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const StructFieldInfo &field) const {
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llvm_unreachable("non-fixed field in fixed struct?");
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}
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};
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/// Accessor for the non-fixed offsets of a struct type.
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class StructNonFixedOffsets : public NonFixedOffsetsImpl {
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SILType TheStruct;
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public:
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StructNonFixedOffsets(SILType type) : TheStruct(type) {
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assert(TheStruct.getStructOrBoundGenericStruct());
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}
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llvm::Value *getOffsetForIndex(IRGenFunction &IGF, unsigned index) override {
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// TODO: do this with StructMetadataLayout::getFieldOffset
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// Get the field offset vector from the struct metadata.
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llvm::Value *metadata = IGF.emitTypeMetadataRefForLayout(TheStruct);
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Address fieldVector = emitAddressOfFieldOffsetVector(IGF, metadata,
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TheStruct.getStructOrBoundGenericStruct());
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// Grab the indexed offset.
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fieldVector = IGF.Builder.CreateConstArrayGEP(fieldVector, index,
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IGF.IGM.getPointerSize());
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return IGF.Builder.CreateLoad(fieldVector);
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}
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MemberAccessStrategy getFieldAccessStrategy(IRGenModule &IGM,
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unsigned nonFixedIndex) {
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auto start =
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IGM.getMetadataLayout(TheStruct.getStructOrBoundGenericStruct())
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.getFieldOffsetVectorOffset();
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// FIXME: Handle resilience
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auto indirectOffset = start.getStatic() +
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(IGM.getPointerSize() * nonFixedIndex);
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return MemberAccessStrategy::getIndirectFixed(indirectOffset,
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MemberAccessStrategy::OffsetKind::Bytes_Word);
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}
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};
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/// A type implementation for non-fixed struct types.
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class NonFixedStructTypeInfo final
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: public StructTypeInfoBase<NonFixedStructTypeInfo,
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WitnessSizedTypeInfo<NonFixedStructTypeInfo>>
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{
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public:
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NonFixedStructTypeInfo(ArrayRef<StructFieldInfo> fields,
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FieldsAreABIAccessible_t fieldsAccessible,
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llvm::Type *T,
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Alignment align,
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IsPOD_t isPOD, IsBitwiseTakable_t isBT,
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IsABIAccessible_t structAccessible)
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: StructTypeInfoBase(StructTypeInfoKind::NonFixedStructTypeInfo,
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fields, fieldsAccessible,
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T, align, isPOD, isBT, structAccessible) {
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}
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// We have an indirect schema.
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void getSchema(ExplosionSchema &s) const override {
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s.add(ExplosionSchema::Element::forAggregate(getStorageType(),
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getBestKnownAlignment()));
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}
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StructNonFixedOffsets
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getNonFixedOffsets(IRGenFunction &IGF, SILType T) const {
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return StructNonFixedOffsets(T);
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}
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MemberAccessStrategy
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getNonFixedFieldAccessStrategy(IRGenModule &IGM, SILType T,
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const StructFieldInfo &field) const {
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return StructNonFixedOffsets(T).getFieldAccessStrategy(IGM,
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field.getNonFixedElementIndex());
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}
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llvm::Value *getEnumTagSinglePayload(IRGenFunction &IGF,
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llvm::Value *numEmptyCases,
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Address structAddr,
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SILType structType,
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bool isOutlined) const override {
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// If we're not emitting the value witness table's implementation,
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// just call that.
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if (!isOutlined) {
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return emitGetEnumTagSinglePayloadCall(IGF, structType, numEmptyCases,
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structAddr);
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}
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return emitGetEnumTagSinglePayloadGenericCall(IGF, structType, *this,
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numEmptyCases, structAddr,
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[this,structType](IRGenFunction &IGF, Address structAddr) {
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return withExtraInhabitantProvidingField(IGF, structAddr, structType,
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IGF.IGM.Int32Ty,
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[&](const FieldImpl &field, llvm::Value *numXI) -> llvm::Value* {
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Address fieldAddr = asImpl().projectFieldAddress(
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IGF, structAddr, structType, field);
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auto fieldTy = field.getType(IGF.IGM, structType);
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return field.getTypeInfo()
|
|
.getExtraInhabitantTagDynamic(IGF, fieldAddr, fieldTy,
|
|
numXI, /*outlined*/ false);
|
|
});
|
|
});
|
|
}
|
|
|
|
void storeEnumTagSinglePayload(IRGenFunction &IGF,
|
|
llvm::Value *whichCase,
|
|
llvm::Value *numEmptyCases,
|
|
Address structAddr,
|
|
SILType structType,
|
|
bool isOutlined) const override {
|
|
// If we're not emitting the value witness table's implementation,
|
|
// just call that.
|
|
if (!isOutlined) {
|
|
return emitStoreEnumTagSinglePayloadCall(IGF, structType, whichCase,
|
|
numEmptyCases, structAddr);
|
|
}
|
|
|
|
emitStoreEnumTagSinglePayloadGenericCall(IGF, structType, *this,
|
|
whichCase, numEmptyCases,
|
|
structAddr,
|
|
[this,structType](IRGenFunction &IGF, Address structAddr,
|
|
llvm::Value *tag) {
|
|
withExtraInhabitantProvidingField(IGF, structAddr, structType,
|
|
IGF.IGM.VoidTy,
|
|
[&](const FieldImpl &field, llvm::Value *numXI) -> llvm::Value* {
|
|
Address fieldAddr = asImpl().projectFieldAddress(
|
|
IGF, structAddr, structType, field);
|
|
auto fieldTy = field.getType(IGF.IGM, structType);
|
|
field.getTypeInfo()
|
|
.storeExtraInhabitantTagDynamic(IGF, tag, fieldAddr, fieldTy,
|
|
/*outlined*/ false);
|
|
return nullptr;
|
|
});
|
|
});
|
|
}
|
|
};
|
|
|
|
class StructTypeBuilder :
|
|
public RecordTypeBuilder<StructTypeBuilder, StructFieldInfo, VarDecl*> {
|
|
|
|
llvm::StructType *StructTy;
|
|
CanType TheStruct;
|
|
public:
|
|
StructTypeBuilder(IRGenModule &IGM, llvm::StructType *structTy,
|
|
CanType type) :
|
|
RecordTypeBuilder(IGM), StructTy(structTy), TheStruct(type) {
|
|
}
|
|
|
|
LoadableStructTypeInfo *createLoadable(ArrayRef<StructFieldInfo> fields,
|
|
StructLayout &&layout,
|
|
unsigned explosionSize) {
|
|
return LoadableStructTypeInfo::create(fields,
|
|
explosionSize,
|
|
layout.getType(),
|
|
layout.getSize(),
|
|
std::move(layout.getSpareBits()),
|
|
layout.getAlignment(),
|
|
layout.isPOD(),
|
|
layout.isAlwaysFixedSize());
|
|
}
|
|
|
|
FixedStructTypeInfo *createFixed(ArrayRef<StructFieldInfo> fields,
|
|
StructLayout &&layout) {
|
|
return FixedStructTypeInfo::create(fields, layout.getType(),
|
|
layout.getSize(),
|
|
std::move(layout.getSpareBits()),
|
|
layout.getAlignment(),
|
|
layout.isPOD(),
|
|
layout.isBitwiseTakable(),
|
|
layout.isAlwaysFixedSize());
|
|
}
|
|
|
|
NonFixedStructTypeInfo *createNonFixed(ArrayRef<StructFieldInfo> fields,
|
|
FieldsAreABIAccessible_t fieldsAccessible,
|
|
StructLayout &&layout) {
|
|
auto structAccessible = IsABIAccessible_t(
|
|
IGM.getSILModule().isTypeMetadataAccessible(TheStruct));
|
|
return NonFixedStructTypeInfo::create(fields, fieldsAccessible,
|
|
layout.getType(),
|
|
layout.getAlignment(),
|
|
layout.isPOD(),
|
|
layout.isBitwiseTakable(),
|
|
structAccessible);
|
|
}
|
|
|
|
StructFieldInfo getFieldInfo(unsigned index,
|
|
VarDecl *field, const TypeInfo &fieldTI) {
|
|
return StructFieldInfo(field, fieldTI);
|
|
}
|
|
|
|
SILType getType(VarDecl *field) {
|
|
assert(field->getDeclContext() == TheStruct->getAnyNominal());
|
|
auto silType = SILType::getPrimitiveAddressType(TheStruct);
|
|
return silType.getFieldType(field, IGM.getSILModule());
|
|
}
|
|
|
|
StructLayout performLayout(ArrayRef<const TypeInfo *> fieldTypes) {
|
|
return StructLayout(IGM, TheStruct->getAnyNominal(),
|
|
LayoutKind::NonHeapObject,
|
|
LayoutStrategy::Optimal, fieldTypes, StructTy);
|
|
}
|
|
};
|
|
|
|
/// A class for lowering Clang records.
|
|
class ClangRecordLowering {
|
|
IRGenModule &IGM;
|
|
StructDecl *SwiftDecl;
|
|
SILType SwiftType;
|
|
const clang::RecordDecl *ClangDecl;
|
|
const clang::ASTContext &ClangContext;
|
|
const clang::ASTRecordLayout &ClangLayout;
|
|
const Size TotalStride;
|
|
const Alignment TotalAlignment;
|
|
SpareBitVector SpareBits;
|
|
|
|
SmallVector<llvm::Type *, 8> LLVMFields;
|
|
SmallVector<ClangFieldInfo, 8> FieldInfos;
|
|
Size NextOffset = Size(0);
|
|
unsigned NextExplosionIndex = 0;
|
|
public:
|
|
ClangRecordLowering(IRGenModule &IGM, StructDecl *swiftDecl,
|
|
const clang::RecordDecl *clangDecl,
|
|
SILType swiftType)
|
|
: IGM(IGM), SwiftDecl(swiftDecl), SwiftType(swiftType),
|
|
ClangDecl(clangDecl), ClangContext(clangDecl->getASTContext()),
|
|
ClangLayout(ClangContext.getASTRecordLayout(clangDecl)),
|
|
TotalStride(Size(ClangLayout.getSize().getQuantity())),
|
|
TotalAlignment(IGM.getCappedAlignment(
|
|
Alignment(ClangLayout.getAlignment()))) {
|
|
SpareBits.reserve(TotalStride.getValue() * 8);
|
|
}
|
|
|
|
void collectRecordFields() {
|
|
if (ClangDecl->isUnion()) {
|
|
collectUnionFields();
|
|
} else {
|
|
collectStructFields();
|
|
}
|
|
}
|
|
|
|
const TypeInfo *createTypeInfo(llvm::StructType *llvmType) {
|
|
llvmType->setBody(LLVMFields, /*packed*/ true);
|
|
return ClangRecordTypeInfo::create(FieldInfos, NextExplosionIndex,
|
|
llvmType, TotalStride,
|
|
std::move(SpareBits), TotalAlignment,
|
|
ClangDecl);
|
|
}
|
|
|
|
private:
|
|
/// Collect all the fields of a union.
|
|
void collectUnionFields() {
|
|
addOpaqueField(Size(0), TotalStride);
|
|
}
|
|
|
|
static bool isImportOfClangField(VarDecl *swiftField,
|
|
const clang::FieldDecl *clangField) {
|
|
assert(swiftField->hasClangNode());
|
|
return (swiftField->getClangNode().castAsDecl() == clangField);
|
|
}
|
|
|
|
void collectStructFields() {
|
|
auto cfi = ClangDecl->field_begin(), cfe = ClangDecl->field_end();
|
|
auto swiftProperties = SwiftDecl->getStoredProperties();
|
|
auto sfi = swiftProperties.begin(), sfe = swiftProperties.end();
|
|
|
|
while (cfi != cfe) {
|
|
const clang::FieldDecl *clangField = *cfi++;
|
|
|
|
// Bitfields are currently never mapped, but that doesn't mean
|
|
// we don't have to copy them.
|
|
if (clangField->isBitField()) {
|
|
// Collect all of the following bitfields.
|
|
unsigned bitStart =
|
|
ClangLayout.getFieldOffset(clangField->getFieldIndex());
|
|
unsigned bitEnd = bitStart + clangField->getBitWidthValue(ClangContext);
|
|
|
|
while (cfi != cfe && (*cfi)->isBitField()) {
|
|
clangField = *cfi++;
|
|
unsigned nextStart =
|
|
ClangLayout.getFieldOffset(clangField->getFieldIndex());
|
|
assert(nextStart >= bitEnd && "laying out bit-fields out of order?");
|
|
|
|
// In a heuristic effort to reduce the number of weird-sized
|
|
// fields, whenever we see a bitfield starting on a 32-bit
|
|
// boundary, start a new storage unit.
|
|
if (nextStart % 32 == 0) {
|
|
addOpaqueBitField(bitStart, bitEnd);
|
|
bitStart = nextStart;
|
|
}
|
|
|
|
bitEnd = nextStart + clangField->getBitWidthValue(ClangContext);
|
|
}
|
|
|
|
addOpaqueBitField(bitStart, bitEnd);
|
|
continue;
|
|
}
|
|
|
|
VarDecl *swiftField;
|
|
if (sfi != sfe) {
|
|
swiftField = *sfi;
|
|
if (isImportOfClangField(swiftField, clangField)) {
|
|
++sfi;
|
|
} else {
|
|
swiftField = nullptr;
|
|
}
|
|
} else {
|
|
swiftField = nullptr;
|
|
}
|
|
|
|
// Try to position this field. If this fails, it's because we
|
|
// didn't lay out padding correctly.
|
|
addStructField(clangField, swiftField);
|
|
}
|
|
|
|
assert(sfi == sfe && "more Swift fields than there were Clang fields?");
|
|
|
|
// We never take advantage of tail padding, because that would prevent
|
|
// us from passing the address of the object off to C, which is a pretty
|
|
// likely scenario for imported C types.
|
|
assert(NextOffset <= TotalStride);
|
|
assert(SpareBits.size() <= TotalStride.getValueInBits());
|
|
if (NextOffset < TotalStride) {
|
|
addPaddingField(TotalStride);
|
|
}
|
|
}
|
|
|
|
/// Place the next struct field at its appropriate offset.
|
|
void addStructField(const clang::FieldDecl *clangField,
|
|
VarDecl *swiftField) {
|
|
unsigned fieldOffset = ClangLayout.getFieldOffset(clangField->getFieldIndex());
|
|
assert(!clangField->isBitField());
|
|
Size offset(fieldOffset / 8);
|
|
|
|
// If we have a Swift import of this type, use our lowered information.
|
|
if (swiftField) {
|
|
auto &fieldTI = cast<LoadableTypeInfo>(
|
|
IGM.getTypeInfo(SwiftType.getFieldType(swiftField, IGM.getSILModule())));
|
|
addField(swiftField, offset, fieldTI);
|
|
return;
|
|
}
|
|
|
|
// Otherwise, add it as an opaque blob.
|
|
auto fieldSize = ClangContext.getTypeSizeInChars(clangField->getType());
|
|
return addOpaqueField(offset, Size(fieldSize.getQuantity()));
|
|
}
|
|
|
|
/// Add opaque storage for bitfields spanning the given range of bits.
|
|
void addOpaqueBitField(unsigned bitBegin, unsigned bitEnd) {
|
|
assert(bitBegin <= bitEnd);
|
|
|
|
// No need to add storage for zero-width bitfields.
|
|
if (bitBegin == bitEnd) return;
|
|
|
|
// Round up to an even number of bytes.
|
|
assert(bitBegin % 8 == 0);
|
|
Size offset = Size(bitBegin / 8);
|
|
Size byteLength = Size((bitEnd - bitBegin + 7) / 8);
|
|
|
|
addOpaqueField(offset, byteLength);
|
|
}
|
|
|
|
/// Add opaque storage at the given offset.
|
|
void addOpaqueField(Size offset, Size fieldSize) {
|
|
// No need to add storage for zero-size fields (e.g. incomplete array
|
|
// decls).
|
|
if (fieldSize.isZero()) return;
|
|
|
|
auto &opaqueTI = IGM.getOpaqueStorageTypeInfo(fieldSize, Alignment(1));
|
|
addField(nullptr, offset, opaqueTI);
|
|
}
|
|
|
|
/// Add storage for an (optional) Swift field at the given offset.
|
|
void addField(VarDecl *swiftField, Size offset,
|
|
const LoadableTypeInfo &fieldType) {
|
|
assert(offset >= NextOffset && "adding fields out of order");
|
|
|
|
// Add a padding field if required.
|
|
if (offset != NextOffset)
|
|
addPaddingField(offset);
|
|
|
|
addFieldInfo(swiftField, fieldType);
|
|
}
|
|
|
|
/// Add information to track a value field at the current offset.
|
|
void addFieldInfo(VarDecl *swiftField, const LoadableTypeInfo &fieldType) {
|
|
unsigned explosionSize = fieldType.getExplosionSize();
|
|
unsigned explosionBegin = NextExplosionIndex;
|
|
NextExplosionIndex += explosionSize;
|
|
unsigned explosionEnd = NextExplosionIndex;
|
|
|
|
ElementLayout layout = ElementLayout::getIncomplete(fieldType);
|
|
auto isEmpty = fieldType.isKnownEmpty(ResilienceExpansion::Maximal);
|
|
if (isEmpty)
|
|
layout.completeEmpty(fieldType.isPOD(ResilienceExpansion::Maximal),
|
|
NextOffset);
|
|
else
|
|
layout.completeFixed(fieldType.isPOD(ResilienceExpansion::Maximal),
|
|
NextOffset, LLVMFields.size());
|
|
|
|
FieldInfos.push_back(
|
|
ClangFieldInfo(swiftField, layout, explosionBegin, explosionEnd));
|
|
|
|
if (!isEmpty) {
|
|
LLVMFields.push_back(fieldType.getStorageType());
|
|
NextOffset += fieldType.getFixedSize();
|
|
SpareBits.append(fieldType.getSpareBits());
|
|
}
|
|
}
|
|
|
|
/// Add padding to get up to the given offset.
|
|
void addPaddingField(Size offset) {
|
|
assert(offset > NextOffset);
|
|
Size count = offset - NextOffset;
|
|
LLVMFields.push_back(llvm::ArrayType::get(IGM.Int8Ty, count.getValue()));
|
|
NextOffset = offset;
|
|
SpareBits.appendSetBits(count.getValueInBits());
|
|
}
|
|
};
|
|
|
|
} // end anonymous namespace
|
|
|
|
/// A convenient macro for delegating an operation to all of the
|
|
/// various struct implementations.
|
|
#define FOR_STRUCT_IMPL(IGF, type, op, ...) do { \
|
|
auto &structTI = IGF.getTypeInfo(type); \
|
|
switch (getStructTypeInfoKind(structTI)) { \
|
|
case StructTypeInfoKind::ClangRecordTypeInfo: \
|
|
return structTI.as<ClangRecordTypeInfo>().op(IGF, __VA_ARGS__); \
|
|
case StructTypeInfoKind::LoadableStructTypeInfo: \
|
|
return structTI.as<LoadableStructTypeInfo>().op(IGF, __VA_ARGS__); \
|
|
case StructTypeInfoKind::FixedStructTypeInfo: \
|
|
return structTI.as<FixedStructTypeInfo>().op(IGF, __VA_ARGS__); \
|
|
case StructTypeInfoKind::NonFixedStructTypeInfo: \
|
|
return structTI.as<NonFixedStructTypeInfo>().op(IGF, __VA_ARGS__); \
|
|
case StructTypeInfoKind::ResilientStructTypeInfo: \
|
|
llvm_unreachable("resilient structs are opaque"); \
|
|
} \
|
|
llvm_unreachable("bad struct type info kind!"); \
|
|
} while (0)
|
|
|
|
Address irgen::projectPhysicalStructMemberAddress(IRGenFunction &IGF,
|
|
Address base,
|
|
SILType baseType,
|
|
VarDecl *field) {
|
|
FOR_STRUCT_IMPL(IGF, baseType, projectFieldAddress, base,
|
|
baseType, field);
|
|
}
|
|
|
|
void irgen::projectPhysicalStructMemberFromExplosion(IRGenFunction &IGF,
|
|
SILType baseType,
|
|
Explosion &base,
|
|
VarDecl *field,
|
|
Explosion &out) {
|
|
FOR_STRUCT_IMPL(IGF, baseType, projectFieldFromExplosion, base, field, out);
|
|
}
|
|
|
|
llvm::Constant *irgen::emitPhysicalStructMemberFixedOffset(IRGenModule &IGM,
|
|
SILType baseType,
|
|
VarDecl *field) {
|
|
FOR_STRUCT_IMPL(IGM, baseType, getConstantFieldOffset, field);
|
|
}
|
|
|
|
MemberAccessStrategy
|
|
irgen::getPhysicalStructMemberAccessStrategy(IRGenModule &IGM,
|
|
SILType baseType, VarDecl *field) {
|
|
FOR_STRUCT_IMPL(IGM, baseType, getFieldAccessStrategy, baseType, field);
|
|
}
|
|
|
|
Optional<unsigned> irgen::getPhysicalStructFieldIndex(IRGenModule &IGM,
|
|
SILType baseType,
|
|
VarDecl *field) {
|
|
FOR_STRUCT_IMPL(IGM, baseType, getFieldIndexIfNotEmpty, field);
|
|
}
|
|
|
|
void IRGenModule::emitStructDecl(StructDecl *st) {
|
|
if (!IRGen.tryEnableLazyTypeMetadata(st))
|
|
emitStructMetadata(*this, st);
|
|
|
|
emitNestedTypeDecls(st->getMembers());
|
|
|
|
if (shouldEmitOpaqueTypeMetadataRecord(st)) {
|
|
emitOpaqueTypeMetadataRecord(st);
|
|
} else {
|
|
emitFieldMetadataRecord(st);
|
|
}
|
|
}
|
|
|
|
namespace {
|
|
/// A type implementation for resilient struct types. This is not a
|
|
/// StructTypeInfoBase at all, since we don't know anything about
|
|
/// the struct's fields.
|
|
class ResilientStructTypeInfo
|
|
: public ResilientTypeInfo<ResilientStructTypeInfo>
|
|
{
|
|
public:
|
|
ResilientStructTypeInfo(llvm::Type *T, IsABIAccessible_t abiAccessible)
|
|
: ResilientTypeInfo(T, abiAccessible) {
|
|
setSubclassKind((unsigned) StructTypeInfoKind::ResilientStructTypeInfo);
|
|
}
|
|
};
|
|
} // end anonymous namespace
|
|
|
|
const TypeInfo *
|
|
TypeConverter::convertResilientStruct(IsABIAccessible_t abiAccessible) {
|
|
llvm::Type *storageType = IGM.OpaquePtrTy->getElementType();
|
|
return new ResilientStructTypeInfo(storageType, abiAccessible);
|
|
}
|
|
|
|
const TypeInfo *TypeConverter::convertStructType(TypeBase *key, CanType type,
|
|
StructDecl *D){
|
|
// All resilient structs have the same opaque lowering, since they are
|
|
// indistinguishable as values --- except that we have to track
|
|
// ABI-accessibility.
|
|
if (IGM.isResilient(D, ResilienceExpansion::Maximal)) {
|
|
auto structAccessible =
|
|
IsABIAccessible_t(IGM.getSILModule().isTypeMetadataAccessible(type));
|
|
return &getResilientStructTypeInfo(structAccessible);
|
|
}
|
|
|
|
// Create the struct type.
|
|
auto ty = IGM.createNominalType(type);
|
|
|
|
// Register a forward declaration before we look at any of the child types.
|
|
addForwardDecl(key);
|
|
|
|
// Use different rules for types imported from C.
|
|
if (D->hasClangNode()) {
|
|
const clang::Decl *clangDecl = D->getClangNode().getAsDecl();
|
|
assert(clangDecl && "Swift struct from an imported C macro?");
|
|
|
|
if (auto clangRecord = dyn_cast<clang::RecordDecl>(clangDecl)) {
|
|
ClangRecordLowering lowering(IGM, D, clangRecord,
|
|
SILType::getPrimitiveObjectType(type));
|
|
lowering.collectRecordFields();
|
|
return lowering.createTypeInfo(ty);
|
|
|
|
} else if (isa<clang::EnumDecl>(clangDecl)) {
|
|
// Fall back to Swift lowering for the enum's representation as a struct.
|
|
assert(std::distance(D->getStoredProperties().begin(),
|
|
D->getStoredProperties().end()) == 1 &&
|
|
"Struct representation of a Clang enum should wrap one value");
|
|
} else if (clangDecl->hasAttr<clang::SwiftNewtypeAttr>()) {
|
|
// Fall back to Swift lowering for the underlying type's
|
|
// representation as a struct member.
|
|
assert(std::distance(D->getStoredProperties().begin(),
|
|
D->getStoredProperties().end()) == 1 &&
|
|
"Struct representation of a swift_newtype should wrap one value");
|
|
} else {
|
|
llvm_unreachable("Swift struct represents unexpected imported type");
|
|
}
|
|
}
|
|
|
|
// Collect all the fields from the type.
|
|
SmallVector<VarDecl*, 8> fields;
|
|
for (VarDecl *VD : D->getStoredProperties())
|
|
fields.push_back(VD);
|
|
|
|
// Build the type.
|
|
StructTypeBuilder builder(IGM, ty, type);
|
|
return builder.layout(fields);
|
|
}
|