llvm-project/llvm/lib/CodeGen/AsmPrinter/DwarfStringPool.cpp

72 lines
2.2 KiB
C++

//===-- llvm/CodeGen/DwarfStringPool.cpp - Dwarf Debug Framework ----------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "DwarfStringPool.h"
#include "llvm/MC/MCStreamer.h"
using namespace llvm;
static std::pair<MCSymbol *, unsigned> &
getEntry(AsmPrinter &Asm,
StringMap<std::pair<MCSymbol *, unsigned>, BumpPtrAllocator &> &Pool,
StringRef Prefix, StringRef Str) {
std::pair<MCSymbol *, unsigned> &Entry =
Pool.GetOrCreateValue(Str).getValue();
if (!Entry.first) {
Entry.second = Pool.size() - 1;
Entry.first = Asm.GetTempSymbol(Prefix, Entry.second);
}
return Entry;
}
MCSymbol *DwarfStringPool::getSymbol(AsmPrinter &Asm, StringRef Str) {
return getEntry(Asm, Pool, Prefix, Str).first;
}
unsigned DwarfStringPool::getIndex(AsmPrinter &Asm, StringRef Str) {
return getEntry(Asm, Pool, Prefix, Str).second;
}
void DwarfStringPool::emit(AsmPrinter &Asm, const MCSection *StrSection,
const MCSection *OffsetSection) {
if (Pool.empty())
return;
// Start the dwarf str section.
Asm.OutStreamer.SwitchSection(StrSection);
// Get all of the string pool entries and put them in an array by their ID so
// we can sort them.
SmallVector<const StringMapEntry<std::pair<MCSymbol *, unsigned>> *, 64>
Entries(Pool.size());
for (const auto &E : Pool)
Entries[E.getValue().second] = &E;
for (const auto &Entry : Entries) {
// Emit a label for reference from debug information entries.
Asm.OutStreamer.EmitLabel(Entry->getValue().first);
// Emit the string itself with a terminating null byte.
Asm.OutStreamer.EmitBytes(
StringRef(Entry->getKeyData(), Entry->getKeyLength() + 1));
}
// If we've got an offset section go ahead and emit that now as well.
if (OffsetSection) {
Asm.OutStreamer.SwitchSection(OffsetSection);
unsigned offset = 0;
unsigned size = 4; // FIXME: DWARF64 is 8.
for (const auto &Entry : Entries) {
Asm.OutStreamer.EmitIntValue(offset, size);
offset += Entry->getKeyLength() + 1;
}
}
}