StringTableBuilder.cpp [plain text]
#include "llvm/MC/StringTableBuilder.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Support/COFF.h"
#include "llvm/Support/Endian.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(Kind kind) {
SmallVector<StringRef, 8> Strings;
Strings.reserve(StringIndexMap.size());
for (auto i = StringIndexMap.begin(), e = StringIndexMap.end(); i != e; ++i)
Strings.push_back(i->getKey());
std::sort(Strings.begin(), Strings.end(), compareBySuffix);
switch (kind) {
case ELF:
case MachO:
StringTable += '\x00';
break;
case WinCOFF:
StringTable.append(4, '\x00');
break;
}
StringRef Previous;
for (StringRef s : Strings) {
if (kind == WinCOFF)
assert(s.size() > COFF::NameSize && "Short string in COFF string table!");
if (Previous.endswith(s)) {
StringIndexMap[s] = StringTable.size() - 1 - s.size();
continue;
}
StringIndexMap[s] = StringTable.size();
StringTable += s;
StringTable += '\x00';
Previous = s;
}
switch (kind) {
case ELF:
break;
case MachO:
while (StringTable.size() % 4)
StringTable += '\x00';
break;
case WinCOFF:
assert(StringTable.size() <= std::numeric_limits<uint32_t>::max());
uint32_t size = static_cast<uint32_t>(StringTable.size());
support::endian::write<uint32_t, support::little, support::unaligned>(
StringTable.data(), size);
break;
}
}
void StringTableBuilder::clear() {
StringTable.clear();
StringIndexMap.clear();
}