lib/CodeGen/AsmPrinter/DwarfAccelTable.cpp - platform/external/llvm - Gitiles

 //=-- llvm/CodeGen/DwarfAccelTable.cpp - Dwarf Accelerator Tables -*- C++ -*-=//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file contains support for writing dwarf accelerator tables.
 //
 //===----------------------------------------------------------------------===//

 #include "llvm/CodeGen/AsmPrinter.h"
 #include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCStreamer.h"
 #include "llvm/MC/MCSymbol.h"
 #include "llvm/Support/Debug.h"
 #include "DwarfAccelTable.h"
 #include "DwarfDebug.h"
 #include "DIE.h"

 using namespace llvm;

 const char *DwarfAccelTable::Atom::AtomTypeString(enum AtomType AT) {
   switch (AT) {
   default: llvm_unreachable("invalid AtomType!");
   case eAtomTypeNULL: return "eAtomTypeNULL";
   case eAtomTypeDIEOffset: return "eAtomTypeDIEOffset";
   case eAtomTypeCUOffset: return "eAtomTypeCUOffset";
   case eAtomTypeTag: return "eAtomTypeTag";
   case eAtomTypeNameFlags: return "eAtomTypeNameFlags";
   case eAtomTypeTypeFlags: return "eAtomTypeTypeFlags";
   }
 }

 // The general case would need to have a less hard coded size for the
 // length of the HeaderData, however, if we're constructing based on a
 // single Atom then we know it will always be: 4 + 4 + 2 + 2.
 DwarfAccelTable::DwarfAccelTable(DwarfAccelTable::Atom atom) :
   Header(12),
   HeaderData(atom) {
 }

 DwarfAccelTable::~DwarfAccelTable() {
   for (size_t i = 0, e = Data.size() ; i < e; ++i)
     delete Data[i];
 }

 void DwarfAccelTable::AddName(StringRef Name, DIE* die) {
   // If the string is in the list already then add this die to the list
   // otherwise add a new one.
   DIEArray &DIEs = Entries[Name];
   DIEs.push_back(die);
 }

 void DwarfAccelTable::ComputeBucketCount(void) {
   // First get the number of unique hashes.
   std::vector<uint32_t> uniques;
   uniques.resize(Data.size());
   for (size_t i = 0; i < Data.size(); ++i)
     uniques[i] = Data[i]->HashValue;
   std::sort(uniques.begin(), uniques.end());
   std::vector<uint32_t>::iterator p =
     std::unique(uniques.begin(), uniques.end());
   uint32_t num = std::distance(uniques.begin(), p);

   // Then compute the bucket size, minimum of 1 bucket.
   if (num > 1024) Header.bucket_count = num/4;
   if (num > 16) Header.bucket_count = num/2;
   else Header.bucket_count = num > 0 ? num : 1;

   Header.hashes_count = num;
 }

 void DwarfAccelTable::FinalizeTable(AsmPrinter *Asm, const char *Prefix) {
   // Create the individual hash data outputs.
   for (StringMap<DIEArray>::const_iterator
          EI = Entries.begin(), EE = Entries.end(); EI != EE; ++EI) {
     struct HashData *Entry = new HashData((*EI).getKeyData());
     for (DIEArray::const_iterator DI = (*EI).second.begin(),
            DE = (*EI).second.end();
          DI != DE; ++DI)
       Entry->addOffset((*DI)->getOffset());
     Data.push_back(Entry);
   }

   // Figure out how many buckets we need, then compute the bucket
   // contents and the final ordering. We'll emit the hashes and offsets
   // by doing a walk during the emission phase. We add temporary
   // symbols to the data so that we can reference them during the offset
   // later, we'll emit them when we emit the data.
   ComputeBucketCount();

   // Compute bucket contents and final ordering.
   Buckets.resize(Header.bucket_count);
   for (size_t i = 0; i < Data.size(); ++i) {
     uint32_t bucket = Data[i]->HashValue % Header.bucket_count;
     Buckets[bucket].push_back(Data[i]);
     Data[i]->Sym = Asm->GetTempSymbol(Prefix, i);
   }
 }

 // Emits the header for the table via the AsmPrinter.
 void DwarfAccelTable::EmitHeader(AsmPrinter *Asm) {
   Asm->OutStreamer.AddComment("Header Magic");
   Asm->EmitInt32(Header.magic);
   Asm->OutStreamer.AddComment("Header Version");
   Asm->EmitInt16(Header.version);
   Asm->OutStreamer.AddComment("Header Hash Function");
   Asm->EmitInt16(Header.hash_function);
   Asm->OutStreamer.AddComment("Header Bucket Count");
   Asm->EmitInt32(Header.bucket_count);
   Asm->OutStreamer.AddComment("Header Hash Count");
   Asm->EmitInt32(Header.hashes_count);
   Asm->OutStreamer.AddComment("Header Data Length");
   Asm->EmitInt32(Header.header_data_len);
   Asm->OutStreamer.AddComment("HeaderData Die Offset Base");
   Asm->EmitInt32(HeaderData.die_offset_base);
   Asm->OutStreamer.AddComment("HeaderData Atom Count");
   Asm->EmitInt32(HeaderData.Atoms.size());
   for (size_t i = 0; i < HeaderData.Atoms.size(); i++) {
     Atom A = HeaderData.Atoms[i];
     Asm->OutStreamer.AddComment(Atom::AtomTypeString(A.type));
     Asm->EmitInt16(A.type);
     Asm->OutStreamer.AddComment(dwarf::FormEncodingString(A.form));
     Asm->EmitInt16(A.form);
   }
 }

 // Walk through and emit the buckets for the table. This will look
 // like a list of numbers of how many elements are in each bucket.
 void DwarfAccelTable::EmitBuckets(AsmPrinter *Asm) {
   unsigned index = 0;
   for (size_t i = 0; i < Buckets.size(); ++i) {
     Asm->OutStreamer.AddComment("Bucket " + Twine(i));
     if (Buckets[i].size() != 0)
       Asm->EmitInt32(index);
     else
       Asm->EmitInt32(UINT32_MAX);
     index += Buckets[i].size();
   }
 }

 // Walk through the buckets and emit the individual hashes for each
 // bucket.
 void DwarfAccelTable::EmitHashes(AsmPrinter *Asm) {
   for (size_t i = 0; i < Buckets.size(); ++i) {
     for (HashList::const_iterator HI = Buckets[i].begin(),
            HE = Buckets[i].end(); HI != HE; ++HI) {
       Asm->OutStreamer.AddComment("Hash in Bucket " + Twine(i));
       Asm->EmitInt32((*HI)->HashValue);
     }
   }
 }

 // Walk through the buckets and emit the individual offsets for each
 // element in each bucket. This is done via a symbol subtraction from the
 // beginning of the section. The non-section symbol will be output later
 // when we emit the actual data.
 void DwarfAccelTable::EmitOffsets(AsmPrinter *Asm, MCSymbol *SecBegin) {
   for (size_t i = 0; i < Buckets.size(); ++i) {
     for (HashList::const_iterator HI = Buckets[i].begin(),
            HE = Buckets[i].end(); HI != HE; ++HI) {
       Asm->OutStreamer.AddComment("Offset in Bucket " + Twine(i));
       MCContext &Context = Asm->OutStreamer.getContext();
       const MCExpr *Sub =
         MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create((*HI)->Sym, Context),
                                 MCSymbolRefExpr::Create(SecBegin, Context),
                                 Context);
       Asm->OutStreamer.EmitValue(Sub, sizeof(uint32_t), 0);
     }
   }
 }

 // Walk through the buckets and emit the full data for each element in
 // the bucket. For the string case emit the dies and the various offsets.
 // Terminate each HashData bucket with 0.
 void DwarfAccelTable::EmitData(AsmPrinter *Asm, DwarfDebug *D) {
   uint64_t PrevHash = UINT64_MAX;
   for (size_t i = 0; i < Buckets.size(); ++i) {
     for (HashList::const_iterator HI = Buckets[i].begin(),
            HE = Buckets[i].end(); HI != HE; ++HI) {
       // Remember to emit the label for our offset.
       Asm->OutStreamer.EmitLabel((*HI)->Sym);
       Asm->OutStreamer.AddComment((*HI)->Str);
       Asm->EmitSectionOffset(D->getStringPoolEntry((*HI)->Str),
                              D->getStringPool());
       Asm->OutStreamer.AddComment("Num DIEs");
       Asm->EmitInt32((*HI)->DIEOffsets.size());
       for (std::vector<uint32_t>::const_iterator
              DI = (*HI)->DIEOffsets.begin(), DE = (*HI)->DIEOffsets.end();
            DI != DE; ++DI) {
         Asm->EmitInt32((*DI));
       }
       // Emit a 0 to terminate the data unless we have a hash collision.
       if (PrevHash != (*HI)->HashValue)
         Asm->EmitInt32(0);
       PrevHash = (*HI)->HashValue;
     }
   }
 }

 // Emit the entire data structure to the output file.
 void DwarfAccelTable::Emit(AsmPrinter *Asm, MCSymbol *SecBegin,
                            DwarfDebug *D) {
   // Emit the header.
   EmitHeader(Asm);

   // Emit the buckets.
   EmitBuckets(Asm);

   // Emit the hashes.
   EmitHashes(Asm);

   // Emit the offsets.
   EmitOffsets(Asm, SecBegin);

   // Emit the hash data.
   EmitData(Asm, D);
 }

 #ifndef NDEBUG
 void DwarfAccelTable::print(raw_ostream &O) {

   Header.print(O);
   HeaderData.print(O);

   O << "Entries: \n";
   for (StringMap<DIEArray>::const_iterator
          EI = Entries.begin(), EE = Entries.end(); EI != EE; ++EI) {
     O << "Name: " << (*EI).getKeyData() << "\n";
     for (DIEArray::const_iterator DI = (*EI).second.begin(),
            DE = (*EI).second.end();
          DI != DE; ++DI)
       (*DI)->print(O);
   }

   O << "Buckets and Hashes: \n";
   for (size_t i = 0; i < Buckets.size(); ++i)
     for (HashList::const_iterator HI = Buckets[i].begin(),
            HE = Buckets[i].end(); HI != HE; ++HI)
       (*HI)->print(O);

   O << "Data: \n";
     for (std::vector<HashData*>::const_iterator
            DI = Data.begin(), DE = Data.end(); DI != DE; ++DI)
       (*DI)->print(O);


 }
 #endif
	//=-- llvm/CodeGen/DwarfAccelTable.cpp - Dwarf Accelerator Tables -- C++ --=//
	//
	// The LLVM Compiler Infrastructure
	//
	// This file is distributed under the University of Illinois Open Source
	// License. See LICENSE.TXT for details.
	//
	//===----------------------------------------------------------------------===//
	//
	// This file contains support for writing dwarf accelerator tables.
	//
	//===----------------------------------------------------------------------===//

	#include "llvm/CodeGen/AsmPrinter.h"
	#include "llvm/MC/MCExpr.h"
	#include "llvm/MC/MCStreamer.h"
	#include "llvm/MC/MCSymbol.h"
	#include "llvm/Support/Debug.h"
	#include "DwarfAccelTable.h"
	#include "DwarfDebug.h"
	#include "DIE.h"

	using namespace llvm;

	const char *DwarfAccelTable::Atom::AtomTypeString(enum AtomType AT) {
	switch (AT) {
	default: llvm_unreachable("invalid AtomType!");
	case eAtomTypeNULL: return "eAtomTypeNULL";
	case eAtomTypeDIEOffset: return "eAtomTypeDIEOffset";
	case eAtomTypeCUOffset: return "eAtomTypeCUOffset";
	case eAtomTypeTag: return "eAtomTypeTag";
	case eAtomTypeNameFlags: return "eAtomTypeNameFlags";
	case eAtomTypeTypeFlags: return "eAtomTypeTypeFlags";
	}
	}

	// The general case would need to have a less hard coded size for the
	// length of the HeaderData, however, if we're constructing based on a
	// single Atom then we know it will always be: 4 + 4 + 2 + 2.
	DwarfAccelTable::DwarfAccelTable(DwarfAccelTable::Atom atom) :
	Header(12),
	HeaderData(atom) {
	}

	DwarfAccelTable::~DwarfAccelTable() {
	for (size_t i = 0, e = Data.size() ; i < e; ++i)
	delete Data[i];
	}

	void DwarfAccelTable::AddName(StringRef Name, DIE* die) {
	// If the string is in the list already then add this die to the list
	// otherwise add a new one.
	DIEArray &DIEs = Entries[Name];
	DIEs.push_back(die);
	}

	void DwarfAccelTable::ComputeBucketCount(void) {
	// First get the number of unique hashes.
	std::vector<uint32_t> uniques;
	uniques.resize(Data.size());
	for (size_t i = 0; i < Data.size(); ++i)
	uniques[i] = Data[i]->HashValue;
	std::sort(uniques.begin(), uniques.end());
	std::vector<uint32_t>::iterator p =
	std::unique(uniques.begin(), uniques.end());
	uint32_t num = std::distance(uniques.begin(), p);

	// Then compute the bucket size, minimum of 1 bucket.
	if (num > 1024) Header.bucket_count = num/4;
	if (num > 16) Header.bucket_count = num/2;
	else Header.bucket_count = num > 0 ? num : 1;

	Header.hashes_count = num;
	}

	void DwarfAccelTable::FinalizeTable(AsmPrinter Asm, const char Prefix) {
	// Create the individual hash data outputs.
	for (StringMap<DIEArray>::const_iterator
	EI = Entries.begin(), EE = Entries.end(); EI != EE; ++EI) {
	struct HashData Entry = new HashData((EI).getKeyData());
	for (DIEArray::const_iterator DI = (*EI).second.begin(),
	DE = (*EI).second.end();
	DI != DE; ++DI)
	Entry->addOffset((*DI)->getOffset());
	Data.push_back(Entry);
	}

	// Figure out how many buckets we need, then compute the bucket
	// contents and the final ordering. We'll emit the hashes and offsets
	// by doing a walk during the emission phase. We add temporary
	// symbols to the data so that we can reference them during the offset
	// later, we'll emit them when we emit the data.
	ComputeBucketCount();

	// Compute bucket contents and final ordering.
	Buckets.resize(Header.bucket_count);
	for (size_t i = 0; i < Data.size(); ++i) {
	uint32_t bucket = Data[i]->HashValue % Header.bucket_count;
	Buckets[bucket].push_back(Data[i]);
	Data[i]->Sym = Asm->GetTempSymbol(Prefix, i);
	}
	}

	// Emits the header for the table via the AsmPrinter.
	void DwarfAccelTable::EmitHeader(AsmPrinter *Asm) {
	Asm->OutStreamer.AddComment("Header Magic");
	Asm->EmitInt32(Header.magic);
	Asm->OutStreamer.AddComment("Header Version");
	Asm->EmitInt16(Header.version);
	Asm->OutStreamer.AddComment("Header Hash Function");
	Asm->EmitInt16(Header.hash_function);
	Asm->OutStreamer.AddComment("Header Bucket Count");
	Asm->EmitInt32(Header.bucket_count);
	Asm->OutStreamer.AddComment("Header Hash Count");
	Asm->EmitInt32(Header.hashes_count);
	Asm->OutStreamer.AddComment("Header Data Length");
	Asm->EmitInt32(Header.header_data_len);
	Asm->OutStreamer.AddComment("HeaderData Die Offset Base");
	Asm->EmitInt32(HeaderData.die_offset_base);
	Asm->OutStreamer.AddComment("HeaderData Atom Count");
	Asm->EmitInt32(HeaderData.Atoms.size());
	for (size_t i = 0; i < HeaderData.Atoms.size(); i++) {
	Atom A = HeaderData.Atoms[i];
	Asm->OutStreamer.AddComment(Atom::AtomTypeString(A.type));
	Asm->EmitInt16(A.type);
	Asm->OutStreamer.AddComment(dwarf::FormEncodingString(A.form));
	Asm->EmitInt16(A.form);
	}
	}

	// Walk through and emit the buckets for the table. This will look
	// like a list of numbers of how many elements are in each bucket.
	void DwarfAccelTable::EmitBuckets(AsmPrinter *Asm) {
	unsigned index = 0;
	for (size_t i = 0; i < Buckets.size(); ++i) {
	Asm->OutStreamer.AddComment("Bucket " + Twine(i));
	if (Buckets[i].size() != 0)
	Asm->EmitInt32(index);
	else
	Asm->EmitInt32(UINT32_MAX);
	index += Buckets[i].size();
	}
	}

	// Walk through the buckets and emit the individual hashes for each
	// bucket.
	void DwarfAccelTable::EmitHashes(AsmPrinter *Asm) {
	for (size_t i = 0; i < Buckets.size(); ++i) {
	for (HashList::const_iterator HI = Buckets[i].begin(),
	HE = Buckets[i].end(); HI != HE; ++HI) {
	Asm->OutStreamer.AddComment("Hash in Bucket " + Twine(i));
	Asm->EmitInt32((*HI)->HashValue);
	}
	}
	}

	// Walk through the buckets and emit the individual offsets for each
	// element in each bucket. This is done via a symbol subtraction from the
	// beginning of the section. The non-section symbol will be output later
	// when we emit the actual data.
	void DwarfAccelTable::EmitOffsets(AsmPrinter Asm, MCSymbol SecBegin) {
	for (size_t i = 0; i < Buckets.size(); ++i) {
	for (HashList::const_iterator HI = Buckets[i].begin(),
	HE = Buckets[i].end(); HI != HE; ++HI) {
	Asm->OutStreamer.AddComment("Offset in Bucket " + Twine(i));
	MCContext &Context = Asm->OutStreamer.getContext();
	const MCExpr *Sub =
	MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create((*HI)->Sym, Context),
	MCSymbolRefExpr::Create(SecBegin, Context),
	Context);
	Asm->OutStreamer.EmitValue(Sub, sizeof(uint32_t), 0);
	}
	}
	}

	// Walk through the buckets and emit the full data for each element in
	// the bucket. For the string case emit the dies and the various offsets.
	// Terminate each HashData bucket with 0.
	void DwarfAccelTable::EmitData(AsmPrinter Asm, DwarfDebug D) {
	uint64_t PrevHash = UINT64_MAX;
	for (size_t i = 0; i < Buckets.size(); ++i) {
	for (HashList::const_iterator HI = Buckets[i].begin(),
	HE = Buckets[i].end(); HI != HE; ++HI) {
	// Remember to emit the label for our offset.
	Asm->OutStreamer.EmitLabel((*HI)->Sym);
	Asm->OutStreamer.AddComment((*HI)->Str);
	Asm->EmitSectionOffset(D->getStringPoolEntry((*HI)->Str),
	D->getStringPool());
	Asm->OutStreamer.AddComment("Num DIEs");
	Asm->EmitInt32((*HI)->DIEOffsets.size());
	for (std::vector<uint32_t>::const_iterator
	DI = (HI)->DIEOffsets.begin(), DE = (HI)->DIEOffsets.end();
	DI != DE; ++DI) {
	Asm->EmitInt32((*DI));
	}
	// Emit a 0 to terminate the data unless we have a hash collision.
	if (PrevHash != (*HI)->HashValue)
	Asm->EmitInt32(0);
	PrevHash = (*HI)->HashValue;
	}
	}
	}

	// Emit the entire data structure to the output file.
	void DwarfAccelTable::Emit(AsmPrinter Asm, MCSymbol SecBegin,
	DwarfDebug *D) {
	// Emit the header.
	EmitHeader(Asm);

	// Emit the buckets.
	EmitBuckets(Asm);

	// Emit the hashes.
	EmitHashes(Asm);

	// Emit the offsets.
	EmitOffsets(Asm, SecBegin);

	// Emit the hash data.
	EmitData(Asm, D);
	}

	#ifndef NDEBUG
	void DwarfAccelTable::print(raw_ostream &O) {

	Header.print(O);
	HeaderData.print(O);

	O << "Entries: \n";
	for (StringMap<DIEArray>::const_iterator
	EI = Entries.begin(), EE = Entries.end(); EI != EE; ++EI) {
	O << "Name: " << (*EI).getKeyData() << "\n";
	for (DIEArray::const_iterator DI = (*EI).second.begin(),
	DE = (*EI).second.end();
	DI != DE; ++DI)
	(*DI)->print(O);
	}

	O << "Buckets and Hashes: \n";
	for (size_t i = 0; i < Buckets.size(); ++i)
	for (HashList::const_iterator HI = Buckets[i].begin(),
	HE = Buckets[i].end(); HI != HE; ++HI)
	(*HI)->print(O);

	O << "Data: \n";
	for (std::vector<HashData*>::const_iterator
	DI = Data.begin(), DE = Data.end(); DI != DE; ++DI)
	(*DI)->print(O);


	}
	#endif