1 //===-- llvm/CodeGen/DwarfStringPool.cpp - Dwarf Debug Framework ----------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 #include "DwarfStringPool.h" 11 #include "llvm/MC/MCStreamer.h" 12 13 using namespace llvm; 14 15 MCSymbol *DwarfStringPool::getSectionSymbol() { return SectionSymbol; } 16 17 static std::pair<MCSymbol *, unsigned> & 18 getEntry(AsmPrinter &Asm, 19 StringMap<std::pair<MCSymbol *, unsigned>, BumpPtrAllocator &> &Pool, 20 StringRef Prefix, StringRef Str) { 21 std::pair<MCSymbol *, unsigned> &Entry = 22 Pool.GetOrCreateValue(Str).getValue(); 23 if (!Entry.first) { 24 Entry.second = Pool.size() - 1; 25 Entry.first = Asm.GetTempSymbol(Prefix, Entry.second); 26 } 27 return Entry; 28 } 29 30 MCSymbol *DwarfStringPool::getSymbol(AsmPrinter &Asm, StringRef Str) { 31 return getEntry(Asm, Pool, Prefix, Str).first; 32 } 33 34 unsigned DwarfStringPool::getIndex(AsmPrinter &Asm, StringRef Str) { 35 return getEntry(Asm, Pool, Prefix, Str).second; 36 } 37 38 void DwarfStringPool::emit(AsmPrinter &Asm, const MCSection *StrSection, 39 const MCSection *OffsetSection, 40 const MCSymbol *StrSecSym) { 41 if (Pool.empty()) 42 return; 43 44 // Start the dwarf str section. 45 Asm.OutStreamer.SwitchSection(StrSection); 46 47 // Get all of the string pool entries and put them in an array by their ID so 48 // we can sort them. 49 SmallVector<const StringMapEntry<std::pair<MCSymbol *, unsigned>> *, 64> 50 Entries(Pool.size()); 51 52 for (const auto &E : Pool) 53 Entries[E.getValue().second] = &E; 54 55 for (const auto &Entry : Entries) { 56 // Emit a label for reference from debug information entries. 57 Asm.OutStreamer.EmitLabel(Entry->getValue().first); 58 59 // Emit the string itself with a terminating null byte. 60 Asm.OutStreamer.EmitBytes( 61 StringRef(Entry->getKeyData(), Entry->getKeyLength() + 1)); 62 } 63 64 // If we've got an offset section go ahead and emit that now as well. 65 if (OffsetSection) { 66 Asm.OutStreamer.SwitchSection(OffsetSection); 67 unsigned offset = 0; 68 unsigned size = 4; // FIXME: DWARF64 is 8. 69 for (const auto &Entry : Entries) { 70 Asm.OutStreamer.EmitIntValue(offset, size); 71 offset += Entry->getKeyLength() + 1; 72 } 73 } 74 } 75
