75 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			75 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C++
		
	
	
	
//===-- llvm/CodeGen/DwarfStringPool.cpp - Dwarf Debug Framework ----------===//
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//
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//                     The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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#include "DwarfStringPool.h"
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#include "llvm/CodeGen/AsmPrinter.h"
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#include "llvm/MC/MCAsmInfo.h"
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#include "llvm/MC/MCStreamer.h"
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using namespace llvm;
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DwarfStringPool::DwarfStringPool(BumpPtrAllocator &A, AsmPrinter &Asm,
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                                 StringRef Prefix)
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    : Pool(A), Prefix(Prefix),
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      ShouldCreateSymbols(Asm.MAI->doesDwarfUseRelocationsAcrossSections()) {}
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DwarfStringPool::EntryRef DwarfStringPool::getEntry(AsmPrinter &Asm,
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                                                    StringRef Str) {
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  auto I = Pool.insert(std::make_pair(Str, EntryTy()));
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  if (I.second) {
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    auto &Entry = I.first->second;
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    Entry.Index = Pool.size() - 1;
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    Entry.Offset = NumBytes;
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    Entry.Symbol = ShouldCreateSymbols ? Asm.createTempSymbol(Prefix) : nullptr;
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    NumBytes += Str.size() + 1;
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    assert(NumBytes > Entry.Offset && "Unexpected overflow");
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  }
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  return EntryRef(*I.first);
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}
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void DwarfStringPool::emit(AsmPrinter &Asm, MCSection *StrSection,
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                           MCSection *OffsetSection) {
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  if (Pool.empty())
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    return;
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  // Start the dwarf str section.
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  Asm.OutStreamer->SwitchSection(StrSection);
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  // Get all of the string pool entries and put them in an array by their ID so
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  // we can sort them.
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  SmallVector<const StringMapEntry<EntryTy> *, 64> Entries(Pool.size());
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  for (const auto &E : Pool)
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    Entries[E.getValue().Index] = &E;
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  for (const auto &Entry : Entries) {
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    assert(ShouldCreateSymbols == static_cast<bool>(Entry->getValue().Symbol) &&
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           "Mismatch between setting and entry");
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    // Emit a label for reference from debug information entries.
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    if (ShouldCreateSymbols)
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      Asm.OutStreamer->EmitLabel(Entry->getValue().Symbol);
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    // Emit the string itself with a terminating null byte.
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    Asm.OutStreamer->AddComment("string offset=" +
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                                Twine(Entry->getValue().Offset));
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    Asm.OutStreamer->EmitBytes(
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        StringRef(Entry->getKeyData(), Entry->getKeyLength() + 1));
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  }
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  // If we've got an offset section go ahead and emit that now as well.
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  if (OffsetSection) {
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    Asm.OutStreamer->SwitchSection(OffsetSection);
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    unsigned size = 4; // FIXME: DWARF64 is 8.
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    for (const auto &Entry : Entries)
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      Asm.OutStreamer->EmitIntValue(Entry->getValue().Offset, size);
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  }
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}
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