replica
/
hanchenye-llvm-project
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

More Mach-O writer improvements. 

llvm-svn: 34740
This commit is contained in:
Nate Begeman 2007-02-28 07:40:50 +00:00
parent 152bfa103e
commit e0232ec706
5 changed files with 79 additions and 39 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
llvm/include/llvm/Target/TargetMachOWriterInfo.h
View File

@ -100,7 +100,8 @@ namespace llvm {
unsigned ToIdx,
OutputBuffer &RelocOut,
OutputBuffer &SecOut,
bool Scattered) const { return 0; }
bool Scattered,
bool Extern) const { return 0; }
uint32_t getCPUType() const { return CPUType; }
uint32_t getCPUSubType() const { return CPUSubType; }

85
llvm/lib/CodeGen/MachOWriter.cpp
View File

@ -107,7 +107,7 @@ namespace llvm {
virtual intptr_t getConstantPoolEntryAddress(unsigned Index) const {
assert(CPLocations.size() > Index && "CP not emitted!");
return CPLocations[Index];
return CPLocations[Index];\
}
virtual intptr_t getJumpTableEntryAddress(unsigned Index) const {
assert(JTLocations.size() > Index && "JT not emitted!");
@ -225,7 +225,10 @@ bool MachOCodeEmitter::finishFunction(MachineFunction &MF) {
Addr = getConstantPoolEntryAddress(MR.getConstantPoolIndex());
MR.setConstantVal(CPSections[MR.getConstantPoolIndex()]);
MR.setResultPointer((void*)Addr);
} else if (!MR.isGlobalValue()) {
} else if (MR.isGlobalValue()) {
// FIXME: This should be a set or something that uniques
MOW.PendingGlobals.push_back(MR.getGlobalValue());
} else {
assert(0 && "Unhandled relocation type");
}
MOS->Relocations.push_back(MR);
@ -334,8 +337,6 @@ void MachOWriter::AddSymbolToSection(MachOSection *Sec, GlobalVariable *GV) {
if (Align == 0)
Align = TM.getTargetData()->getPrefTypeAlignment(Ty);
MachOSym Sym(GV, Mang->getValueName(GV), Sec->Index, TM);
// Reserve space in the .bss section for this symbol while maintaining the
// desired section alignment, which must be at least as much as required by
// this symbol.
@ -353,12 +354,17 @@ void MachOWriter::AddSymbolToSection(MachOSection *Sec, GlobalVariable *GV) {
for (unsigned i = 0; i < AlignedSize; ++i)
SecDataOut.outbyte(0);
}
// Globals without external linkage apparently do not go in the symbol table.
if (GV->getLinkage() != GlobalValue::InternalLinkage) {
MachOSym Sym(GV, Mang->getValueName(GV), Sec->Index, TM);
Sym.n_value = Sec->size;
SymbolTable.push_back(Sym);
}
// Record the offset of the symbol, and then allocate space for it.
// FIXME: remove when we have unified size + output buffer
Sym.n_value = Sec->size;
Sec->size += Size;
SymbolTable.push_back(Sym);
// Now that we know what section the GlovalVariable is going to be emitted
// into, update our mappings.
// FIXME: We may also need to update this when outputting non-GlobalVariable
@ -387,12 +393,9 @@ void MachOWriter::EmitGlobal(GlobalVariable *GV) {
// For undefined (N_UNDF) external (N_EXT) types, n_value is the size in
// bytes of the symbol.
ExtOrCommonSym.n_value = Size;
// If the symbol is external, we'll put it on a list of symbols whose
// addition to the symbol table is being pended until we find a reference
if (NoInit)
PendingSyms.push_back(ExtOrCommonSym);
else
SymbolTable.push_back(ExtOrCommonSym);
SymbolTable.push_back(ExtOrCommonSym);
// Remember that we've seen this symbol
GVOffset[GV] = Size;
return;
}
// Otherwise, this symbol is part of the .bss section.
@ -526,7 +529,13 @@ void MachOWriter::EmitHeaderAndLoadCommands() {
currentAddr += MOS->size;
}
// Step #6: Calculate the number of relocations for each section and write out
// Step #6: Emit the symbol table to temporary buffers, so that we know the
// size of the string table when we write the next load command. This also
// sorts and assigns indices to each of the symbols, which is necessary for
// emitting relocations to externally-defined objects.
BufferSymbolAndStringTable();
// Step #7: Calculate the number of relocations for each section and write out
// the section commands for each section
currentAddr += SEG.fileoff;
for (std::vector<MachOSection*>::iterator I = SectionList.begin(),
@ -554,10 +563,6 @@ void MachOWriter::EmitHeaderAndLoadCommands() {
FHOut.outword(MOS->reserved3);
}
// Step #7: Emit the symbol table to temporary buffers, so that we know the
// size of the string table when we write the next load command.
BufferSymbolAndStringTable();
// Step #8: Emit LC_SYMTAB/LC_DYSYMTAB load commands
SymTab.symoff = currentAddr;
SymTab.nsyms = SymbolTable.size();
@ -632,6 +637,17 @@ void MachOWriter::BufferSymbolAndStringTable() {
// 2. defined external symbols (sorted by name)
// 3. undefined external symbols (sorted by name)
// Before sorting the symbols, check the PendingGlobals for any undefined
// globals that need to be put in the symbol table.
for (std::vector<GlobalValue*>::iterator I = PendingGlobals.begin(),
E = PendingGlobals.end(); I != E; ++I) {
if (GVOffset[*I] == 0 && GVSection[*I] == 0) {
MachOSym UndfSym(*I, Mang->getValueName(*I), MachOSym::NO_SECT, TM);
SymbolTable.push_back(UndfSym);
GVOffset[*I] = -1;
}
}
// Sort the symbols by name, so that when we partition the symbols by scope
// of definition, we won't have to sort by name within each partition.
std::sort(SymbolTable.begin(), SymbolTable.end(), MachOSymCmp());
@ -690,14 +706,17 @@ void MachOWriter::BufferSymbolAndStringTable() {
OutputBuffer SymTOut(SymT, is64Bit, isLittleEndian);
unsigned index = 0;
for (std::vector<MachOSym>::iterator I = SymbolTable.begin(),
E = SymbolTable.end(); I != E; ++I) {
E = SymbolTable.end(); I != E; ++I, ++index) {
// Add the section base address to the section offset in the n_value field
// to calculate the full address.
// FIXME: handle symbols where the n_value field is not the address
GlobalValue *GV = const_cast<GlobalValue*>(I->GV);
if (GV && GVSection[GV])
I->n_value += GVSection[GV]->addr;
if (GV && (GVOffset[GV] == -1))
GVOffset[GV] = index;
// Emit nlist to buffer
SymTOut.outword(I->n_strx);
@ -717,10 +736,13 @@ void MachOWriter::CalculateRelocations(MachOSection &MOS) {
for (unsigned i = 0, e = MOS.Relocations.size(); i != e; ++i) {
MachineRelocation &MR = MOS.Relocations[i];
unsigned TargetSection = MR.getConstantVal();
unsigned TargetAddr;
unsigned TargetIndex;
// This is a scattered relocation entry if it points to a global value with
// a non-zero offset.
bool Scattered = false;
bool Extern = false;
// Since we may not have seen the GlobalValue we were interested in yet at
// the time we emitted the relocation for it, fix it up now so that it
@ -729,24 +751,29 @@ void MachOWriter::CalculateRelocations(MachOSection &MOS) {
GlobalValue *GV = MR.getGlobalValue();
MachOSection *MOSPtr = GVSection[GV];
intptr_t Offset = GVOffset[GV];
Scattered = TargetSection != 0;
// If we have never seen the global before, it must be to a symbol
// defined in another module (N_UNDF).
if (!MOSPtr) {
cerr << "Trying to relocate unknown global " << *GV << '\n';
continue;
//abort();
// FIXME: need to append stub suffix
Extern = true;
TargetAddr = 0;
TargetIndex = GVOffset[GV];
} else {
Scattered = TargetSection != 0;
TargetSection = MOSPtr->Index;
MachOSection &To = *SectionList[TargetSection - 1];
TargetAddr = To.addr;
TargetIndex = To.Index;
}
TargetSection = MOSPtr->Index;
MR.setResultPointer((void*)Offset);
}
OutputBuffer RelocOut(MOS.RelocBuffer, is64Bit, isLittleEndian);
OutputBuffer SecOut(MOS.SectionData, is64Bit, isLittleEndian);
MachOSection &To = *SectionList[TargetSection - 1];
MOS.nreloc += GetTargetRelocation(MR, MOS.Index, To.addr, To.Index,
RelocOut, SecOut, Scattered);
MOS.nreloc += GetTargetRelocation(MR, MOS.Index, TargetAddr, TargetIndex,
RelocOut, SecOut, Scattered, Extern);
}
}

8
llvm/lib/CodeGen/MachOWriter.h
View File

@ -583,7 +583,7 @@ namespace llvm {
/// PendingSyms - This is a 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 SymbolTable.
std::vector<MachOSym> PendingSyms;
std::vector<GlobalValue*> PendingGlobals;
/// DynamicSymbolTable - This is just a vector of indices into
/// SymbolTable to aid in emitting the DYSYMTAB load command.
@ -613,10 +613,12 @@ namespace llvm {
unsigned ToIndex,
OutputBuffer &RelocOut,
OutputBuffer &SecOut,
bool Scattered) {
bool Scattered,
bool Extern) {
return TM.getMachOWriterInfo()->GetTargetRelocation(MR, FromIdx, ToAddr,
ToIndex, RelocOut,
SecOut, Scattered);
SecOut, Scattered,
Extern);
}
};
}

20
llvm/lib/Target/PowerPC/PPCMachOWriterInfo.cpp
View File

@ -35,13 +35,11 @@ unsigned PPCMachOWriterInfo::GetTargetRelocation(MachineRelocation &MR,
unsigned ToIdx,
OutputBuffer &RelocOut,
OutputBuffer &SecOut,
bool Scattered) const {
bool Scattered,
bool isExtern) const {
unsigned NumRelocs = 0;
uint64_t Addr = 0;
// Keep track of whether or not this is an externally defined relocation.
bool isExtern = false;
// Get the address of whatever it is we're relocating, if possible.
if (!isExtern)
Addr = (uintptr_t)MR.getResultPointer() + ToAddr;
@ -83,12 +81,24 @@ unsigned PPCMachOWriterInfo::GetTargetRelocation(MachineRelocation &MR,
break;
case PPC::reloc_pcrel_bx:
{
// FIXME: Presumably someday we will need to branch to other, non-extern
// functions too. Need to figure out some way to distinguish between
// target is BB and target is function.
if (isExtern) {
MachORelocation BR24(MR.getMachineCodeOffset(), ToIdx, true, 2,
isExtern, PPC_RELOC_BR24, Scattered,
(intptr_t)MR.getMachineCodeOffset());
RelocOut.outword(BR24.getAddress());
RelocOut.outword(BR24.getPackedFields());
++NumRelocs;
}
Addr -= MR.getMachineCodeOffset();
Addr >>= 2;
Addr &= 0xFFFFFF;
Addr <<= 2;
Addr |= (SecOut[MR.getMachineCodeOffset()] << 24);
Addr |= (SecOut[MR.getMachineCodeOffset()+3] & 0x3);
SecOut.fixword(Addr, MR.getMachineCodeOffset());
break;
}

2
llvm/lib/Target/PowerPC/PPCMachOWriterInfo.h
View File

@ -34,7 +34,7 @@ namespace llvm {
unsigned ToIdx,
OutputBuffer &RelocOut,
OutputBuffer &SecOut,
bool Scattered) const;
bool Scattered, bool Extern) const;
// Constants for the relocation r_type field.
// See <mach-o/ppc/reloc.h>