use std::vector instead of std::list for both Section and Symbol lists because

we care more about random access than insertion/deletion of elements.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75828 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Bruno Cardoso Lopes 2009-07-15 20:49:10 +00:00
parent cf20031f60
commit 4b70fab658
5 changed files with 193 additions and 190 deletions

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@ -52,6 +52,70 @@ namespace llvm {
EV_CURRENT = 1
};
/// ELFSym - This struct contains information about each symbol that is
/// added to logical symbol table for the module. This is eventually
/// turned into a real symbol table in the file.
struct ELFSym {
// The global value this symbol matches. This should be null if the symbol
// is not a global value.
const GlobalValue *GV;
// ELF specific fields
unsigned NameIdx; // Index in .strtab of name, once emitted.
uint64_t Value;
unsigned Size;
uint8_t Info;
uint8_t Other;
unsigned short SectionIdx;
// Symbol index into the Symbol table
unsigned SymTabIdx;
enum {
STB_LOCAL = 0,
STB_GLOBAL = 1,
STB_WEAK = 2
};
enum {
STT_NOTYPE = 0,
STT_OBJECT = 1,
STT_FUNC = 2,
STT_SECTION = 3,
STT_FILE = 4
};
enum {
STV_DEFAULT = 0, // Visibility is specified by binding type
STV_INTERNAL = 1, // Defined by processor supplements
STV_HIDDEN = 2, // Not visible to other components
STV_PROTECTED = 3 // Visible in other components but not preemptable
};
ELFSym(const GlobalValue *gv) : GV(gv), NameIdx(0), Value(0),
Size(0), Info(0), Other(STV_DEFAULT),
SectionIdx(0), SymTabIdx(0) {}
unsigned getBind() const { return (Info >> 4) & 0xf; }
unsigned getType() const { return Info & 0xf; }
bool isLocalBind() const { return getBind() == STB_LOCAL; }
void setBind(unsigned X) {
assert(X == (X & 0xF) && "Bind value out of range!");
Info = (Info & 0x0F) | (X << 4);
}
void setType(unsigned X) {
assert(X == (X & 0xF) && "Type value out of range!");
Info = (Info & 0xF0) | X;
}
void setVisibility(unsigned V) {
assert(V == (V & 0x3) && "Visibility value out of range!");
Other = V;
}
};
/// ELFSection - This struct contains information about each section that is
/// emitted to the file. This is eventually turned into the section header
/// table at the end of the file.
@ -117,73 +181,12 @@ namespace llvm {
/// SectionIdx - The number of the section in the Section Table.
unsigned short SectionIdx;
/// Sym - The symbol to represent this section if it has one.
ELFSym *Sym;
ELFSection(const std::string &name, bool isLittleEndian, bool is64Bit)
: BinaryObject(name, isLittleEndian, is64Bit), Type(0), Flags(0), Addr(0),
Offset(0), Size(0), Link(0), Info(0), Align(0), EntSize(0) {}
};
/// ELFSym - This struct contains information about each symbol that is
/// added to logical symbol table for the module. This is eventually
/// turned into a real symbol table in the file.
struct ELFSym {
// The global value this symbol matches. This should be null if the symbol
// is not a global value.
const GlobalValue *GV;
// ELF specific fields
unsigned NameIdx; // Index in .strtab of name, once emitted.
uint64_t Value;
unsigned Size;
uint8_t Info;
uint8_t Other;
unsigned short SectionIdx;
// Symbol index into the Symbol table
unsigned SymTabIdx;
enum {
STB_LOCAL = 0,
STB_GLOBAL = 1,
STB_WEAK = 2
};
enum {
STT_NOTYPE = 0,
STT_OBJECT = 1,
STT_FUNC = 2,
STT_SECTION = 3,
STT_FILE = 4
};
enum {
STV_DEFAULT = 0, // Visibility is specified by binding type
STV_INTERNAL = 1, // Defined by processor supplements
STV_HIDDEN = 2, // Not visible to other components
STV_PROTECTED = 3 // Visible in other components but not preemptable
};
ELFSym(const GlobalValue *gv) : GV(gv), NameIdx(0), Value(0),
Size(0), Info(0), Other(STV_DEFAULT),
SectionIdx(ELFSection::SHN_UNDEF),
SymTabIdx(0) {}
unsigned getBind() { return (Info >> 4) & 0xf; }
unsigned getType() { return Info & 0xf; }
void setBind(unsigned X) {
assert(X == (X & 0xF) && "Bind value out of range!");
Info = (Info & 0x0F) | (X << 4);
}
void setType(unsigned X) {
assert(X == (X & 0xF) && "Type value out of range!");
Info = (Info & 0xF0) | X;
}
void setVisibility(unsigned V) {
assert(V == (V & 0x3) && "Type value out of range!");
Other = V;
}
Offset(0), Size(0), Link(0), Info(0), Align(0), EntSize(0), Sym(0) {}
};
/// ELFRelocation - This class contains all the information necessary to

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@ -60,23 +60,18 @@ void ELFCodeEmitter::startFunction(MachineFunction &MF) {
bool ELFCodeEmitter::finishFunction(MachineFunction &MF) {
// Add a symbol to represent the function.
const Function *F = MF.getFunction();
ELFSym FnSym(F);
FnSym.setType(ELFSym::STT_FUNC);
FnSym.setBind(EW.getGlobalELFBinding(F));
FnSym.setVisibility(EW.getGlobalELFVisibility(F));
FnSym.SectionIdx = ES->SectionIdx;
FnSym.Size = ES->getCurrentPCOffset()-FnStartOff;
ELFSym *FnSym = new ELFSym(F);
FnSym->setType(ELFSym::STT_FUNC);
FnSym->setBind(EW.getGlobalELFBinding(F));
FnSym->setVisibility(EW.getGlobalELFVisibility(F));
FnSym->SectionIdx = ES->SectionIdx;
FnSym->Size = ES->getCurrentPCOffset()-FnStartOff;
// Offset from start of Section
FnSym.Value = FnStartOff;
FnSym->Value = FnStartOff;
// Locals should go on the symbol list front
if (!F->hasPrivateLinkage()) {
if (FnSym.getBind() == ELFSym::STB_LOCAL)
EW.SymbolList.push_front(FnSym);
else
EW.SymbolList.push_back(FnSym);
}
if (!F->hasPrivateLinkage())
EW.SymbolList.push_back(FnSym);
// Emit constant pool to appropriate section(s)
emitConstantPool(MF.getConstantPool());

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@ -235,13 +235,13 @@ void ELFWriter::EmitGlobal(const GlobalValue *GV) {
// Handle ELF Bind, Visibility and Type for the current symbol
unsigned SymBind = getGlobalELFBinding(GV);
ELFSym GblSym(GV);
GblSym.setBind(SymBind);
GblSym.setVisibility(getGlobalELFVisibility(GV));
GblSym.setType(getGlobalELFType(GV));
ELFSym *GblSym = new ELFSym(GV);
GblSym->setBind(SymBind);
GblSym->setVisibility(getGlobalELFVisibility(GV));
GblSym->setType(getGlobalELFType(GV));
if (isELFUndefSym(GV)) {
GblSym.SectionIdx = ELFSection::SHN_UNDEF;
GblSym->SectionIdx = ELFSection::SHN_UNDEF;
} else {
assert(isa<GlobalVariable>(GV) && "GV not a global variable!");
const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV);
@ -254,41 +254,41 @@ void ELFWriter::EmitGlobal(const GlobalValue *GV) {
const TargetData *TD = TM.getTargetData();
unsigned Align = TD->getPreferredAlignment(GVar);
unsigned Size = TD->getTypeAllocSize(GVar->getInitializer()->getType());
GblSym.Size = Size;
GblSym->Size = Size;
if (isELFCommonSym(GV)) {
GblSym.SectionIdx = ELFSection::SHN_COMMON;
GblSym->SectionIdx = ELFSection::SHN_COMMON;
getSection(S->getName(), ELFSection::SHT_NOBITS, SectionFlags, 1);
// A new linkonce section is created for each global in the
// common section, the default alignment is 1 and the symbol
// value contains its alignment.
GblSym.Value = Align;
GblSym->Value = Align;
} else if (isELFBssSym(GV)) {
ELFSection &ES =
getSection(S->getName(), ELFSection::SHT_NOBITS, SectionFlags);
GblSym.SectionIdx = ES.SectionIdx;
GblSym->SectionIdx = ES.SectionIdx;
// Update the size with alignment and the next object can
// start in the right offset in the section
if (Align) ES.Size = (ES.Size + Align-1) & ~(Align-1);
ES.Align = std::max(ES.Align, Align);
// GblSym.Value should contain the virtual offset inside the section.
// GblSym->Value should contain the virtual offset inside the section.
// Virtual because the BSS space is not allocated on ELF objects
GblSym.Value = ES.Size;
GblSym->Value = ES.Size;
ES.Size += Size;
} else if (isELFDataSym(GV)) {
ELFSection &ES =
getSection(S->getName(), ELFSection::SHT_PROGBITS, SectionFlags);
GblSym.SectionIdx = ES.SectionIdx;
GblSym->SectionIdx = ES.SectionIdx;
// GblSym.Value should contain the symbol offset inside the section,
// GblSym->Value should contain the symbol offset inside the section,
// and all symbols should start on their required alignment boundary
ES.Align = std::max(ES.Align, Align);
GblSym.Value = (ES.size() + (Align-1)) & (-Align);
GblSym->Value = (ES.size() + (Align-1)) & (-Align);
ES.emitAlignment(ES.Align);
// Emit the global to the data section 'ES'
@ -296,13 +296,8 @@ void ELFWriter::EmitGlobal(const GlobalValue *GV) {
}
}
// Local symbols should come first on the symbol table.
if (!GV->hasPrivateLinkage()) {
if (SymBind == ELFSym::STB_LOCAL)
SymbolList.push_front(GblSym);
else
SymbolList.push_back(GblSym);
}
if (!GV->hasPrivateLinkage())
SymbolList.push_back(GblSym);
}
void ELFWriter::EmitGlobalConstantStruct(const ConstantStruct *CVS,
@ -419,23 +414,17 @@ bool ELFWriter::doFinalization(Module &M) {
if (TAI->getNonexecutableStackDirective())
getNonExecStackSection();
// Emit a symbol for each section created until now
for (std::map<std::string, ELFSection*>::iterator I = SectionLookup.begin(),
E = SectionLookup.end(); I != E; ++I) {
ELFSection *ES = I->second;
// Skip null section
if (ES->SectionIdx == 0) continue;
ELFSym SectionSym(0);
SectionSym.SectionIdx = ES->SectionIdx;
SectionSym.Size = 0;
SectionSym.setBind(ELFSym::STB_LOCAL);
SectionSym.setType(ELFSym::STT_SECTION);
SectionSym.setVisibility(ELFSym::STV_DEFAULT);
// Local symbols go in the list front
SymbolList.push_front(SectionSym);
// Emit a symbol for each section created until now, skip null section
for (unsigned i = 1, e = SectionList.size(); i < e; ++i) {
ELFSection &ES = *SectionList[i];
ELFSym *SectionSym = new ELFSym(0);
SectionSym->SectionIdx = ES.SectionIdx;
SectionSym->Size = 0;
SectionSym->setBind(ELFSym::STB_LOCAL);
SectionSym->setType(ELFSym::STT_SECTION);
SectionSym->setVisibility(ELFSym::STV_DEFAULT);
SymbolList.push_back(SectionSym);
ES.Sym = SymbolList.back();
}
// Emit string table
@ -454,6 +443,7 @@ bool ELFWriter::doFinalization(Module &M) {
OutputSectionsAndSectionTable();
// We are done with the abstract symbols.
SymbolList.clear();
SectionList.clear();
NumSections = 0;
@ -466,26 +456,26 @@ bool ELFWriter::doFinalization(Module &M) {
void ELFWriter::EmitRelocations() {
// Create Relocation sections for each section which needs it.
for (std::list<ELFSection>::iterator I = SectionList.begin(),
E = SectionList.end(); I != E; ++I) {
for (unsigned i=0, e=SectionList.size(); i < e; ++i) {
ELFSection &S = *SectionList[i];
// This section does not have relocations
if (!I->hasRelocations()) continue;
if (!S.hasRelocations()) continue;
// Get the relocation section for section 'I'
// Get the relocation section for section 'S'
bool HasRelA = TEW->hasRelocationAddend();
ELFSection &RelSec = getRelocSection(I->getName(), HasRelA,
ELFSection &RelSec = getRelocSection(S.getName(), HasRelA,
TEW->getPrefELFAlignment());
// 'Link' - Section hdr idx of the associated symbol table
// 'Info' - Section hdr idx of the section to which the relocation applies
ELFSection &SymTab = getSymbolTableSection();
RelSec.Link = SymTab.SectionIdx;
RelSec.Info = I->SectionIdx;
RelSec.Info = S.SectionIdx;
RelSec.EntSize = TEW->getRelocationEntrySize();
// Get the relocations from Section
std::vector<MachineRelocation> Relos = I->getRelocations();
std::vector<MachineRelocation> Relos = S.getRelocations();
for (std::vector<MachineRelocation>::iterator MRI = Relos.begin(),
MRE = Relos.end(); MRI != MRE; ++MRI) {
MachineRelocation &MR = *MRI;
@ -510,15 +500,10 @@ void ELFWriter::EmitRelocations() {
SymIdx = GblSymLookup[G];
Addend = TEW->getAddendForRelTy(RelType);
} else {
// Get the symbol index for the section symbol referenced
// by the relocation
unsigned SectionIdx = MR.getConstantVal();
// TODO: use a map for this.
for (std::list<ELFSym>::iterator I = SymbolList.begin(),
E = SymbolList.end(); I != E; ++I)
if ((SectionIdx == I->SectionIdx) &&
(I->getType() == ELFSym::STT_SECTION)) {
SymIdx = I->SymTabIdx;
break;
}
SymIdx = SectionList[SectionIdx]->Sym->SymTabIdx;
Addend = (uint64_t)MR.getResultPointer();
}
@ -596,17 +581,17 @@ void ELFWriter::EmitStringTable() {
// Walk on the symbol list and write symbol names into the
// string table.
unsigned Index = 1;
for (std::list<ELFSym>::iterator I = SymbolList.begin(),
E = SymbolList.end(); I != E; ++I) {
for (unsigned i = 0, e = SymbolList.size(); i < e; ++i) {
ELFSym &Sym = *SymbolList[i];
// Use the name mangler to uniquify the LLVM symbol.
std::string Name;
if (I->GV) Name.append(Mang->getMangledName(I->GV));
if (Sym.GV) Name.append(Mang->getMangledName(Sym.GV));
if (Name.empty()) {
I->NameIdx = 0;
Sym.NameIdx = 0;
} else {
I->NameIdx = Index;
Sym.NameIdx = Index;
StrTab.emitString(Name);
// Keep track of the number of bytes emitted to this section.
@ -617,11 +602,38 @@ void ELFWriter::EmitStringTable() {
StrTab.Size = Index;
}
// SortSymbols - On the symbol table local symbols must come before
// all other symbols with non-local bindings. The return value is
// the position of the first non local symbol.
unsigned ELFWriter::SortSymbols() {
unsigned FirstNonLocalSymbol, i, e;
std::vector<ELFSym*> LocalSyms, OtherSyms;
for (i = 0, e = SymbolList.size(); i < e; ++i) {
if (SymbolList[i]->isLocalBind())
LocalSyms.push_back(SymbolList[i]);
else
OtherSyms.push_back(SymbolList[i]);
}
SymbolList.clear();
FirstNonLocalSymbol = LocalSyms.size();
for (i = 0; i < FirstNonLocalSymbol; ++i)
SymbolList.push_back(LocalSyms[i]);
for (i = 0, e = OtherSyms.size(); i < e; ++i)
SymbolList.push_back(OtherSyms[i]);
LocalSyms.clear();
OtherSyms.clear();
return FirstNonLocalSymbol;
}
/// EmitSymbolTable - Emit the symbol table itself.
void ELFWriter::EmitSymbolTable() {
if (!SymbolList.size()) return; // Empty symbol table.
unsigned FirstNonLocalSymbol = 1;
// Now that we have emitted the string table and know the offset into the
// string table of each symbol, emit the symbol table itself.
ELFSection &SymTab = getSymbolTableSection();
@ -634,29 +646,26 @@ void ELFWriter::EmitSymbolTable() {
SymTab.EntSize = TEW->getSymTabEntrySize();
// The first entry in the symtab is the null symbol
ELFSym NullSym = ELFSym(0);
EmitSymbol(SymTab, NullSym);
SymbolList.insert(SymbolList.begin(), new ELFSym(0));
// Emit all the symbols to the symbol table. Skip the null
// symbol, cause it's emitted already
unsigned Index = 1;
for (std::list<ELFSym>::iterator I = SymbolList.begin(),
E = SymbolList.end(); I != E; ++I, ++Index) {
// Keep track of the first non-local symbol
if (I->getBind() == ELFSym::STB_LOCAL)
FirstNonLocalSymbol++;
// Reorder the symbol table with local symbols first!
unsigned FirstNonLocalSymbol = SortSymbols();
// Emit all the symbols to the symbol table.
for (unsigned i = 0, e = SymbolList.size(); i < e; ++i) {
ELFSym &Sym = *SymbolList[i];
// Emit symbol to the symbol table
EmitSymbol(SymTab, *I);
EmitSymbol(SymTab, Sym);
// Record the symbol table index for each global value
if (I->GV)
GblSymLookup[I->GV] = Index;
if (Sym.GV) GblSymLookup[Sym.GV] = i;
// Keep track on the symbol index into the symbol table
I->SymTabIdx = Index;
Sym.SymTabIdx = i;
}
// One greater than the symbol table index of the last local symbol
SymTab.Info = FirstNonLocalSymbol;
SymTab.Size = SymTab.size();
}
@ -676,15 +685,14 @@ void ELFWriter::EmitSectionTableStringTable() {
// the string table.
unsigned Index = 0;
for (std::list<ELFSection>::iterator I = SectionList.begin(),
E = SectionList.end(); I != E; ++I) {
for (unsigned i=0, e=SectionList.size(); i < e; ++i) {
// Set the index into the table. Note if we have lots of entries with
// common suffixes, we could memoize them here if we cared.
I->NameIdx = Index;
SHStrTab.emitString(I->getName());
SectionList[i]->NameIdx = Index;
SHStrTab.emitString(SectionList[i]->getName());
// Keep track of the number of bytes emitted to this section.
Index += I->getName().size()+1;
Index += SectionList[i]->getName().size()+1;
}
// Set the size of .shstrtab now that we know what it is.
@ -699,29 +707,24 @@ void ELFWriter::OutputSectionsAndSectionTable() {
// Pass #1: Compute the file offset for each section.
size_t FileOff = ElfHdr.size(); // File header first.
// Adjust alignment of all section if needed.
for (std::list<ELFSection>::iterator I = SectionList.begin(),
E = SectionList.end(); I != E; ++I) {
// Section idx 0 has 0 offset
if (!I->SectionIdx)
continue;
if (!I->size()) {
I->Offset = FileOff;
// Adjust alignment of all section if needed, skip the null section.
for (unsigned i=1, e=SectionList.size(); i < e; ++i) {
ELFSection &ES = *SectionList[i];
if (!ES.size()) {
ES.Offset = FileOff;
continue;
}
// Update Section size
if (!I->Size)
I->Size = I->size();
if (!ES.Size)
ES.Size = ES.size();
// Align FileOff to whatever the alignment restrictions of the section are.
if (I->Align)
FileOff = (FileOff+I->Align-1) & ~(I->Align-1);
if (ES.Align)
FileOff = (FileOff+ES.Align-1) & ~(ES.Align-1);
I->Offset = FileOff;
FileOff += I->Size;
ES.Offset = FileOff;
FileOff += ES.Size;
}
// Align Section Header.
@ -745,8 +748,8 @@ void ELFWriter::OutputSectionsAndSectionTable() {
BinaryObject SHdrTable(isLittleEndian, is64Bit);
// Emit all of sections to the file and build the section header table.
while (!SectionList.empty()) {
ELFSection &S = *SectionList.begin();
for (unsigned i=0, e=SectionList.size(); i < e; ++i) {
ELFSection &S = *SectionList[i];
DOUT << "SectionIdx: " << S.SectionIdx << ", Name: " << S.getName()
<< ", Size: " << S.Size << ", Offset: " << S.Offset
<< ", SectionData Size: " << S.size() << "\n";
@ -763,7 +766,6 @@ void ELFWriter::OutputSectionsAndSectionTable() {
}
EmitSectionHeader(SHdrTable, S);
SectionList.pop_front();
}
// Align output for the section table.

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@ -16,7 +16,6 @@
#include "llvm/ADT/SetVector.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include <list>
#include <map>
namespace llvm {
@ -95,13 +94,13 @@ namespace llvm {
BinaryObject ElfHdr;
/// SectionList - This is the list of sections that we have emitted to the
/// file. Once the file has been completely built, the section header table
/// file. Once the file has been completely built, the section header table
/// is constructed from this info.
std::list<ELFSection> SectionList;
std::vector<ELFSection*> SectionList;
unsigned NumSections; // Always = SectionList.size()
/// SectionLookup - This is a mapping from section name to section number in
/// the SectionList.
/// the SectionList. Used to quickly gather the Section Index from TAI names
std::map<std::string, ELFSection*> SectionLookup;
/// GblSymLookup - This is a mapping from global value to a symbol index
@ -109,17 +108,18 @@ namespace llvm {
/// must be quickly mapped to a symbol table index
std::map<const GlobalValue*, uint32_t> GblSymLookup;
/// SymbolList - This is the list of symbols emitted to the symbol table
/// Local symbols go to the front and Globals to the back.
std::list<ELFSym> SymbolList;
/// SymbolList - This is the list of symbols emitted to the symbol table.
/// When the SymbolList is finally built, local symbols must be placed in
/// the beginning while non-locals at the end.
std::vector<ELFSym*> SymbolList;
/// PendingGlobals - List of externally defined symbols that we have been
/// asked to emit, but have not seen a reference to. When a reference
/// is seen, the symbol will move from this list to the SymbolList.
SetVector<GlobalValue*> PendingGlobals;
// Remove tab from section name prefix. This is necessary becase TAI
// sometimes return a section name prefixed with a "\t" char. This is
// Remove tab from section name prefix. This is necessary becase TAI
// sometimes return a section name prefixed with elf unused chars. This is
// a little bit dirty. FIXME: find a better approach, maybe add more
// methods to TAI to get the clean name?
void fixNameForSection(std::string &Name) {
@ -140,14 +140,14 @@ namespace llvm {
/// section if one does not already exist.
ELFSection &getSection(const std::string &Name, unsigned Type,
unsigned Flags = 0, unsigned Align = 0) {
std::string SectionName(Name);
fixNameForSection(SectionName);
std::string SName(Name);
fixNameForSection(SName);
ELFSection *&SN = SectionLookup[SectionName];
ELFSection *&SN = SectionLookup[SName];
if (SN) return *SN;
SectionList.push_back(ELFSection(SectionName, isLittleEndian, is64Bit));
SN = &SectionList.back();
SectionList.push_back(new ELFSection(SName, isLittleEndian, is64Bit));
SN = SectionList.back();
SN->SectionIdx = NumSections++;
SN->Type = Type;
SN->Flags = Flags;
@ -245,6 +245,7 @@ namespace llvm {
void EmitSymbolTable();
void EmitStringTable();
void OutputSectionsAndSectionTable();
unsigned SortSymbols();
};
}

View File

@ -65,6 +65,8 @@ long int X86ELFWriterInfo::getAddendForRelTy(unsigned RelTy) const {
switch(RelTy) {
case R_X86_64_PC32: return -4;
break;
case R_X86_64_32: return 0;
break;
default:
llvm_unreachable("unknown x86 relocation type");
}