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2e8d016a56
NFC except that I've also added support for nullable pointers, where 0 is a valid value (not an extra inhabitant). I'll use this for executors.
124 lines
4.4 KiB
C++
124 lines
4.4 KiB
C++
//===--- ExtraInhabitants.h - Extra inhabitant routines ---------*- C++ -*-===//
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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 defines routines for working with extra inhabitants.
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//
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//===----------------------------------------------------------------------===//
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#ifndef SWIFT_IRGEN_EXTRAINHABITANTS_H
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#define SWIFT_IRGEN_EXTRAINHABITANTS_H
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#include "IRGen.h"
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namespace llvm {
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class APInt;
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class ConstantInt;
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class Value;
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}
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namespace swift {
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namespace irgen {
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class Address;
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class Alignment;
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class IRGenFunction;
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class IRGenModule;
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/// Whether the zero pointer is a valid value (i.e. not a valid
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/// extra inhabitant) of a particular pointer type.
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enum IsNullable_t: bool {
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IsNotNullable = false,
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IsNullable = true
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};
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/// Information about a particular pointer type.
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struct PointerInfo {
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Alignment PointeeAlign;
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uint8_t NumReservedLowBits;
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IsNullable_t Nullable;
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static PointerInfo forHeapObject(const IRGenModule &IGM);
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static PointerInfo forFunction(const IRGenModule &IGM);
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static PointerInfo forAligned(Alignment pointeeAlign) {
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return {pointeeAlign, 0, IsNotNullable};
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}
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PointerInfo withNullable(IsNullable_t nullable) const {
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return {PointeeAlign, NumReservedLowBits, nullable};
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}
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/// Return the number of extra inhabitant representations for
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/// pointers with these properties: i.e. the number of values
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/// that do not collide with any valid pointers.
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unsigned getExtraInhabitantCount(const IRGenModule &IGM) const;
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/// Return an indexed extra inhabitant constant for a pointer
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/// with these properties.
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///
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/// If the pointer appears within a larger aggregate, the
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/// 'bits' and 'offset' arguments can be used to position
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/// the inhabitant within the larger integer constant.
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llvm::APInt getFixedExtraInhabitantValue(const IRGenModule &IGM,
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unsigned bits,
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unsigned index,
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unsigned offset) const;
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/// Given the address of storage for a pointer with these
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/// properties, return the extra inhabitant index of the
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/// value, or -1 if the value is a valid pointer. Always
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/// produces an i32.
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llvm::Value *getExtraInhabitantIndex(IRGenFunction &IGF,
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Address src) const;
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/// Store an extra inhabitant representation for the given
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/// dynamic extra inhabitant index into the given storage.
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void storeExtraInhabitant(IRGenFunction &IGF,
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llvm::Value *index,
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Address dest) const;
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};
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/*****************************************************************************/
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/// \group Extra inhabitants of heap object pointers.
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/// Return the number of extra inhabitant representations for heap objects,
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/// that is, the number of invalid heap object pointer values that can be used
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/// to represent enum tags for enums involving a reference type as a payload.
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unsigned getHeapObjectExtraInhabitantCount(const IRGenModule &IGM);
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/// Return an indexed extra inhabitant constant for a heap object pointer.
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///
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/// If the pointer appears within a larger aggregate, the 'bits' and 'offset'
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/// arguments can be used to position the inhabitant within the larger integer
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/// constant.
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llvm::APInt getHeapObjectFixedExtraInhabitantValue(const IRGenModule &IGM,
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unsigned bits,
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unsigned index,
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unsigned offset);
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/// Calculate the index of a heap object extra inhabitant representation stored
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/// in memory.
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llvm::Value *getHeapObjectExtraInhabitantIndex(IRGenFunction &IGF,
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Address src);
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/// Calculate an extra inhabitant representation from an index and store it to
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/// memory.
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void storeHeapObjectExtraInhabitant(IRGenFunction &IGF,
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llvm::Value *index,
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Address dest);
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} // end namespace irgen
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} // end namespace swift
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#endif
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