llvm-project/llvm/lib/MC/StringTableBuilder.cpp

52 lines
1.4 KiB
C++

//===-- StringTableBuilder.cpp - String table building utility ------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/MC/StringTableBuilder.h"
#include "llvm/ADT/SmallVector.h"
using namespace llvm;
static bool compareBySuffix(StringRef a, StringRef b) {
size_t sizeA = a.size();
size_t sizeB = b.size();
size_t len = std::min(sizeA, sizeB);
for (size_t i = 0; i < len; ++i) {
char ca = a[sizeA - i - 1];
char cb = b[sizeB - i - 1];
if (ca != cb)
return ca > cb;
}
return sizeA > sizeB;
}
void StringTableBuilder::finalize() {
SmallVector<StringRef, 8> Strings;
for (auto i = StringIndexMap.begin(), e = StringIndexMap.end(); i != e; ++i)
Strings.push_back(i->getKey());
std::sort(Strings.begin(), Strings.end(), compareBySuffix);
// FIXME: Starting with a null byte is ELF specific. Generalize this so we
// can use the class with other object formats.
StringTable += '\x00';
StringRef Previous;
for (StringRef s : Strings) {
if (Previous.endswith(s)) {
StringIndexMap[s] = StringTable.size() - 1 - s.size();
continue;
}
StringIndexMap[s] = StringTable.size();
StringTable += s;
StringTable += '\x00';
Previous = s;
}
}