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
diff --git a/lib/CodeGen/ELFWriter.cpp b/lib/CodeGen/ELFWriter.cpp
index 05b7361..a89dae4 100644
--- a/lib/CodeGen/ELFWriter.cpp
+++ b/lib/CodeGen/ELFWriter.cpp
@@ -235,13 +235,13 @@
// 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 @@
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 @@
}
}
- // 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 @@
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 @@
OutputSectionsAndSectionTable();
// We are done with the abstract symbols.
+ SymbolList.clear();
SectionList.clear();
NumSections = 0;
@@ -466,26 +456,26 @@
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 @@
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 @@
// 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 @@
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 @@
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 @@
// 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 @@
// 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 @@
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 @@
}
EmitSectionHeader(SHdrTable, S);
- SectionList.pop_front();
}
// Align output for the section table.