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#pragma once
#ifdef __GNUC__
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-parameter"
#endif
//===- llvm/CodeGen/DwarfStringPoolEntry.h - String pool entry --*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_DWARFSTRINGPOOLENTRY_H
#define LLVM_CODEGEN_DWARFSTRINGPOOLENTRY_H
#include "llvm/ADT/PointerUnion.h"
#include "llvm/ADT/StringMap.h"
namespace llvm {
class MCSymbol;
/// Data for a string pool entry.
struct DwarfStringPoolEntry {
static constexpr unsigned NotIndexed = -1;
MCSymbol *Symbol = nullptr;
uint64_t Offset = 0;
unsigned Index = 0;
bool isIndexed() const { return Index != NotIndexed; }
};
/// DwarfStringPoolEntryRef: Dwarf string pool entry reference.
///
/// Dwarf string pool entry keeps string value and its data.
/// There are two variants how data are represented:
///
/// 1. By value - StringMapEntry<DwarfStringPoolEntry>.
/// 2. By pointer - StringMapEntry<DwarfStringPoolEntry *>.
///
/// The "By pointer" variant allows for reducing memory usage for the case
/// when string pool entry does not have data: it keeps the null pointer
/// and so no need to waste space for the full DwarfStringPoolEntry.
/// It is recommended to use "By pointer" variant if not all entries
/// of dwarf string pool have corresponding DwarfStringPoolEntry.
class DwarfStringPoolEntryRef {
/// Pointer type for "By value" string entry.
using ByValStringEntryPtr = const StringMapEntry<DwarfStringPoolEntry> *;
/// Pointer type for "By pointer" string entry.
using ByPtrStringEntryPtr = const StringMapEntry<DwarfStringPoolEntry *> *;
/// Pointer to the dwarf string pool Entry.
PointerUnion<ByValStringEntryPtr, ByPtrStringEntryPtr> MapEntry = nullptr;
public:
DwarfStringPoolEntryRef() = default;
/// ASSUMPTION: DwarfStringPoolEntryRef keeps pointer to \p Entry,
/// thus specified entry mustn`t be reallocated.
DwarfStringPoolEntryRef(const StringMapEntry<DwarfStringPoolEntry> &Entry)
: MapEntry(&Entry) {}
/// ASSUMPTION: DwarfStringPoolEntryRef keeps pointer to \p Entry,
/// thus specified entry mustn`t be reallocated.
DwarfStringPoolEntryRef(const StringMapEntry<DwarfStringPoolEntry *> &Entry)
: MapEntry(&Entry) {
assert(MapEntry.get<ByPtrStringEntryPtr>()->second != nullptr);
}
explicit operator bool() const { return !MapEntry.isNull(); }
/// \returns symbol for the dwarf string.
MCSymbol *getSymbol() const {
assert(getEntry().Symbol && "No symbol available!");
return getEntry().Symbol;
}
/// \returns offset for the dwarf string.
uint64_t getOffset() const { return getEntry().Offset; }
/// \returns index for the dwarf string.
unsigned getIndex() const {
assert(getEntry().isIndexed() && "Index is not set!");
return getEntry().Index;
}
/// \returns string.
StringRef getString() const {
if (MapEntry.is<ByValStringEntryPtr>())
return MapEntry.get<ByValStringEntryPtr>()->first();
return MapEntry.get<ByPtrStringEntryPtr>()->first();
}
/// \returns the entire string pool entry for convenience.
const DwarfStringPoolEntry &getEntry() const {
if (MapEntry.is<ByValStringEntryPtr>())
return MapEntry.get<ByValStringEntryPtr>()->second;
return *MapEntry.get<ByPtrStringEntryPtr>()->second;
}
bool operator==(const DwarfStringPoolEntryRef &X) const {
return MapEntry.getOpaqueValue() == X.MapEntry.getOpaqueValue();
}
bool operator!=(const DwarfStringPoolEntryRef &X) const {
return MapEntry.getOpaqueValue() != X.MapEntry.getOpaqueValue();
}
};
} // end namespace llvm
#endif
#ifdef __GNUC__
#pragma GCC diagnostic pop
#endif
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