84 lines
2.9 KiB
C++
84 lines
2.9 KiB
C++
//===- NonRelocatableStringpool.h -------------------------------*- 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_NONRELOCATABLESTRINGPOOL_H
|
|
#define LLVM_CODEGEN_NONRELOCATABLESTRINGPOOL_H
|
|
|
|
#include "llvm/CodeGen/DwarfStringPoolEntry.h"
|
|
#include "llvm/Support/Allocator.h"
|
|
#include <cstdint>
|
|
#include <vector>
|
|
|
|
namespace llvm {
|
|
|
|
/// A string table that doesn't need relocations.
|
|
///
|
|
/// Use this class when a string table doesn't need relocations.
|
|
/// This class provides this ability by just associating offsets with strings.
|
|
class NonRelocatableStringpool {
|
|
public:
|
|
/// Entries are stored into the StringMap and simply linked together through
|
|
/// the second element of this pair in order to keep track of insertion
|
|
/// order.
|
|
using MapTy = StringMap<DwarfStringPoolEntry, BumpPtrAllocator>;
|
|
|
|
NonRelocatableStringpool(
|
|
std::function<StringRef(StringRef Input)> Translator = nullptr,
|
|
bool PutEmptyString = false)
|
|
: Translator(Translator) {
|
|
if (PutEmptyString)
|
|
EmptyString = getEntry("");
|
|
}
|
|
|
|
DwarfStringPoolEntryRef getEntry(StringRef S);
|
|
|
|
/// Get the offset of string \p S in the string table. This can insert a new
|
|
/// element or return the offset of a pre-existing one.
|
|
uint64_t getStringOffset(StringRef S) { return getEntry(S).getOffset(); }
|
|
|
|
/// Get permanent storage for \p S (but do not necessarily emit \p S in the
|
|
/// output section). A latter call to getStringOffset() with the same string
|
|
/// will chain it though.
|
|
///
|
|
/// \returns The StringRef that points to permanent storage to use
|
|
/// in place of \p S.
|
|
StringRef internString(StringRef S);
|
|
|
|
uint64_t getSize() { return CurrentEndOffset; }
|
|
|
|
/// Return the list of strings to be emitted. This does not contain the
|
|
/// strings which were added via internString only.
|
|
std::vector<DwarfStringPoolEntryRef> getEntriesForEmission() const;
|
|
|
|
private:
|
|
MapTy Strings;
|
|
uint64_t CurrentEndOffset = 0;
|
|
unsigned NumEntries = 0;
|
|
DwarfStringPoolEntryRef EmptyString;
|
|
std::function<StringRef(StringRef Input)> Translator;
|
|
};
|
|
|
|
/// Helper for making strong types.
|
|
template <typename T, typename S> class StrongType : public T {
|
|
public:
|
|
template <typename... Args>
|
|
explicit StrongType(Args... A) : T(std::forward<Args>(A)...) {}
|
|
};
|
|
|
|
/// It's very easy to introduce bugs by passing the wrong string pool.
|
|
/// By using strong types the interface enforces that the right
|
|
/// kind of pool is used.
|
|
struct UniqueTag {};
|
|
struct OffsetsTag {};
|
|
using UniquingStringPool = StrongType<NonRelocatableStringpool, UniqueTag>;
|
|
using OffsetsStringPool = StrongType<NonRelocatableStringpool, OffsetsTag>;
|
|
|
|
} // end namespace llvm
|
|
|
|
#endif // LLVM_CODEGEN_NONRELOCATABLESTRINGPOOL_H
|