llvm-project/llvm/tools/dsymutil/NonRelocatableStringpool.h

71 lines
2.2 KiB
C++

//===-- NonRelocatableStringpool.h - A simple stringpool -----------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_TOOLS_DSYMUTIL_NONRELOCATABLESTRINGPOOL_H
#define LLVM_TOOLS_DSYMUTIL_NONRELOCATABLESTRINGPOOL_H
#include "llvm/ADT/StringMap.h"
namespace llvm {
namespace dsymutil {
/// \brief A string table that doesn't need relocations.
///
/// We are doing a final link, no need for a string table that
/// has relocation entries for every reference to it. This class
/// provides this ablitity by just associating offsets with
/// strings.
class NonRelocatableStringpool {
public:
/// \brief 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.
typedef StringMap<std::pair<uint32_t, StringMapEntryBase *>, BumpPtrAllocator>
MapTy;
NonRelocatableStringpool()
: CurrentEndOffset(0), Sentinel(0), Last(&Sentinel) {
// Legacy dsymutil puts an empty string at the start of the line
// table.
getStringOffset("");
}
/// \brief Get the offset of string \p S in the string table. This
/// can insert a new element or return the offset of a preexisitng
/// one.
uint32_t getStringOffset(StringRef S);
/// \brief Get permanent storage for \p S (but do not necessarily
/// emit \p S in the output section).
/// \returns The StringRef that points to permanent storage to use
/// in place of \p S.
StringRef internString(StringRef S);
// \brief Return the first entry of the string table.
const MapTy::MapEntryTy *getFirstEntry() const {
return getNextEntry(&Sentinel);
}
// \brief Get the entry following \p E in the string table or null
// if \p E was the last entry.
const MapTy::MapEntryTy *getNextEntry(const MapTy::MapEntryTy *E) const {
return static_cast<const MapTy::MapEntryTy *>(E->getValue().second);
}
uint64_t getSize() { return CurrentEndOffset; }
private:
MapTy Strings;
uint32_t CurrentEndOffset;
MapTy::MapEntryTy Sentinel, *Last;
};
}
}
#endif