Add the Object Code Emitter class. Original patch by Aaron Gray, I did some
cleanup, removed some #includes and moved Object Code Emitter out-of-line.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74813 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachOWriter.cpp b/lib/CodeGen/MachOWriter.cpp
index 163df69..1dbbf15 100644
--- a/lib/CodeGen/MachOWriter.cpp
+++ b/lib/CodeGen/MachOWriter.cpp
@@ -46,12 +46,12 @@
/// AddMachOWriter - Concrete function to add the Mach-O writer to the function
/// pass manager.
-MachineCodeEmitter *AddMachOWriter(PassManagerBase &PM,
+ObjectCodeEmitter *AddMachOWriter(PassManagerBase &PM,
raw_ostream &O,
TargetMachine &TM) {
MachOWriter *MOW = new MachOWriter(O, TM);
PM.add(MOW);
- return &MOW->getMachineCodeEmitter();
+ return MOW->getObjectCodeEmitter();
}
//===----------------------------------------------------------------------===//
@@ -60,8 +60,9 @@
char MachOWriter::ID = 0;
-MachOWriter::MachOWriter(raw_ostream &o, TargetMachine &tm)
- : MachineFunctionPass(&ID), O(o), TM(tm) {
+MachOWriter::MachOWriter(raw_ostream &o, TargetMachine &tm)
+ : MachineFunctionPass(&ID), O(o), TM(tm)
+ {
is64Bit = TM.getTargetData()->getPointerSizeInBits() == 64;
isLittleEndian = TM.getTargetData()->isLittleEndian();
@@ -69,11 +70,11 @@
// Create the machine code emitter object for this target.
- MCE = new MachOCodeEmitter(*this);
+ MachOCE = new MachOCodeEmitter(*this, *getTextSection(true));
}
MachOWriter::~MachOWriter() {
- delete MCE;
+ delete MachOCE;
}
bool MachOWriter::doInitialization(Module &M) {
@@ -97,13 +98,13 @@
/// the Mach-O file to 'O'.
bool MachOWriter::doFinalization(Module &M) {
// FIXME: we don't handle debug info yet, we should probably do that.
-
- // Okay, the.text section has been completed, build the .data, .bss, and
+ // Okay, the.text section has been completed, build the .data, .bss, and
// "common" sections next.
+
for (Module::global_iterator I = M.global_begin(), E = M.global_end();
I != E; ++I)
EmitGlobal(I);
-
+
// Emit the header and load commands.
EmitHeaderAndLoadCommands();
@@ -133,38 +134,32 @@
// 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.
- OutputBuffer SecDataOut(Sec->SectionData, is64Bit, isLittleEndian);
+ OutputBuffer SecDataOut(Sec->getData(), is64Bit, isLittleEndian);
if (Align) {
- uint64_t OrigSize = Sec->size;
Align = Log2_32(Align);
Sec->align = std::max(unsigned(Sec->align), Align);
- Sec->size = (Sec->size + Align - 1) & ~(Align-1);
- // Add alignment padding to buffer as well.
- // FIXME: remove when we have unified size + output buffer
- unsigned AlignedSize = Sec->size - OrigSize;
- for (unsigned i = 0; i < AlignedSize; ++i)
- SecDataOut.outbyte(0);
+ Sec->emitAlignment(Sec->align);
}
// Globals without external linkage apparently do not go in the symbol table.
if (!GV->hasLocalLinkage()) {
MachOSym Sym(GV, Mang->getValueName(GV), Sec->Index, TAI);
- Sym.n_value = Sec->size;
+ 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
- Sec->size += Size;
-
- // Now that we know what section the GlovalVariable is going to be emitted
+
+ // 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
// GlobalValues such as functions.
- GVSection[GV] = Sec;
- GVOffset[GV] = Sec->SectionData.size();
+ GVSection[GV] = Sec;
+ GVOffset[GV] = Sec->size();
+
// Allocate space in the section for the global.
for (unsigned i = 0; i < Size; ++i)
SecDataOut.outbyte(0);
@@ -174,7 +169,7 @@
const Type *Ty = GV->getType()->getElementType();
unsigned Size = TM.getTargetData()->getTypeAllocSize(Ty);
bool NoInit = !GV->hasInitializer();
-
+
// If this global has a zero initializer, it is part of the .bss or common
// section.
if (NoInit || GV->getInitializer()->isNullValue()) {
@@ -183,8 +178,7 @@
// merged with other symbols.
if (NoInit || GV->hasLinkOnceLinkage() || GV->hasWeakLinkage() ||
GV->hasCommonLinkage()) {
- MachOSym ExtOrCommonSym(GV, Mang->getValueName(GV),
- MachOSym::NO_SECT, TAI);
+ MachOSym ExtOrCommonSym(GV, Mang->getValueName(GV), MachOSym::NO_SECT, TAI);
// For undefined (N_UNDF) external (N_EXT) types, n_value is the size in
// bytes of the symbol.
ExtOrCommonSym.n_value = Size;
@@ -198,15 +192,14 @@
AddSymbolToSection(BSS, GV);
return;
}
-
+
// Scalar read-only data goes in a literal section if the scalar is 4, 8, or
// 16 bytes, or a cstring. Other read only data goes into a regular const
// section. Read-write data goes in the data section.
- MachOSection *Sec = GV->isConstant() ? getConstSection(GV->getInitializer()) :
+ MachOSection *Sec = GV->isConstant() ? getConstSection(GV->getInitializer()) :
getDataSection();
AddSymbolToSection(Sec, GV);
- InitMem(GV->getInitializer(), &Sec->SectionData[0], GVOffset[GV],
- TM.getTargetData(), Sec->Relocations);
+ InitMem(GV->getInitializer(), GVOffset[GV], TM.getTargetData(), Sec);
}
@@ -214,21 +207,22 @@
void MachOWriter::EmitHeaderAndLoadCommands() {
// Step #0: Fill in the segment load command size, since we need it to figure
// out the rest of the header fields
+
MachOSegment SEG("", is64Bit);
SEG.nsects = SectionList.size();
- SEG.cmdsize = SEG.cmdSize(is64Bit) +
+ SEG.cmdsize = SEG.cmdSize(is64Bit) +
SEG.nsects * SectionList[0]->cmdSize(is64Bit);
-
+
// Step #1: calculate the number of load commands. We always have at least
// one, for the LC_SEGMENT load command, plus two for the normal
// and dynamic symbol tables, if there are any symbols.
Header.ncmds = SymbolTable.empty() ? 1 : 3;
-
+
// Step #2: calculate the size of the load commands
Header.sizeofcmds = SEG.cmdsize;
if (!SymbolTable.empty())
Header.sizeofcmds += SymTab.cmdsize + DySymTab.cmdsize;
-
+
// Step #3: write the header to the file
// Local alias to shortenify coming code.
DataBuffer &FH = Header.HeaderData;
@@ -243,15 +237,15 @@
FHOut.outword(Header.flags);
if (is64Bit)
FHOut.outword(Header.reserved);
-
+
// Step #4: Finish filling in the segment load command and write it out
for (std::vector<MachOSection*>::iterator I = SectionList.begin(),
E = SectionList.end(); I != E; ++I)
- SEG.filesize += (*I)->size;
+ SEG.filesize += (*I)->size();
SEG.vmsize = SEG.filesize;
SEG.fileoff = Header.cmdSize(is64Bit) + Header.sizeofcmds;
-
+
FHOut.outword(SEG.cmd);
FHOut.outword(SEG.cmdsize);
FHOut.outstring(SEG.segname, 16);
@@ -263,42 +257,42 @@
FHOut.outword(SEG.initprot);
FHOut.outword(SEG.nsects);
FHOut.outword(SEG.flags);
-
- // Step #5: Finish filling in the fields of the MachOSections
+
+ // Step #5: Finish filling in the fields of the MachOSections
uint64_t currentAddr = 0;
for (std::vector<MachOSection*>::iterator I = SectionList.begin(),
E = SectionList.end(); I != E; ++I) {
MachOSection *MOS = *I;
MOS->addr = currentAddr;
MOS->offset = currentAddr + SEG.fileoff;
-
// FIXME: do we need to do something with alignment here?
- currentAddr += MOS->size;
+ currentAddr += MOS->size();
}
-
+
// 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(),
E = SectionList.end(); I != E; ++I) {
MachOSection *MOS = *I;
+
// Convert the relocations to target-specific relocations, and fill in the
// relocation offset for this section.
CalculateRelocations(*MOS);
MOS->reloff = MOS->nreloc ? currentAddr : 0;
currentAddr += MOS->nreloc * 8;
-
+
// write the finalized section command to the output buffer
FHOut.outstring(MOS->sectname, 16);
FHOut.outstring(MOS->segname, 16);
FHOut.outaddr(MOS->addr);
- FHOut.outaddr(MOS->size);
+ FHOut.outaddr(MOS->size());
FHOut.outword(MOS->offset);
FHOut.outword(MOS->align);
FHOut.outword(MOS->reloff);
@@ -309,7 +303,7 @@
if (is64Bit)
FHOut.outword(MOS->reserved3);
}
-
+
// Step #8: Emit LC_SYMTAB/LC_DYSYMTAB load commands
SymTab.symoff = currentAddr;
SymTab.nsyms = SymbolTable.size();
@@ -345,39 +339,40 @@
FHOut.outword(DySymTab.nextrel);
FHOut.outword(DySymTab.locreloff);
FHOut.outword(DySymTab.nlocrel);
-
+
O.write((char*)&FH[0], FH.size());
}
/// EmitSections - Now that we have constructed the file header and load
/// commands, emit the data for each section to the file.
-
void MachOWriter::EmitSections() {
for (std::vector<MachOSection*>::iterator I = SectionList.begin(),
E = SectionList.end(); I != E; ++I)
// Emit the contents of each section
- O.write((char*)&(*I)->SectionData[0], (*I)->size);
+ if ((*I)->size())
+ O.write((char*)&(*I)->getData()[0], (*I)->size());
}
+
+/// EmitRelocations - emit relocation data from buffer.
void MachOWriter::EmitRelocations() {
for (std::vector<MachOSection*>::iterator I = SectionList.begin(),
E = SectionList.end(); I != E; ++I)
// Emit the relocation entry data for each section.
- O.write((char*)&(*I)->RelocBuffer[0], (*I)->RelocBuffer.size());
+ if ((*I)->RelocBuffer.size())
+ O.write((char*)&(*I)->RelocBuffer[0], (*I)->RelocBuffer.size());
}
/// BufferSymbolAndStringTable - Sort the symbols we encountered and assign them
/// each a string table index so that they appear in the correct order in the
/// output file.
-
void MachOWriter::BufferSymbolAndStringTable() {
// The order of the symbol table is:
// 1. local symbols
// 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) {
@@ -389,19 +384,15 @@
// 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(), MachOSym::SymCmp());
- // Parition the symbol table entries so that all local symbols come before
+ // Parition the symbol table entries so that all local symbols come before
// all symbols with external linkage. { 1 | 2 3 }
-
- std::partition(SymbolTable.begin(), SymbolTable.end(),
- MachOSym::PartitionByLocal);
-
+ std::partition(SymbolTable.begin(), SymbolTable.end(), MachOSym::PartitionByLocal);
+
// Advance iterator to beginning of external symbols and partition so that
// all external symbols defined in this module come before all external
// symbols defined elsewhere. { 1 | 2 | 3 }
-
for (std::vector<MachOSym>::iterator I = SymbolTable.begin(),
E = SymbolTable.end(); I != E; ++I) {
if (!MachOSym::PartitionByLocal(*I)) {
@@ -410,10 +401,9 @@
}
}
- // Calculate the starting index for each of the local, extern defined, and
+ // Calculate the starting index for each of the local, extern defined, and
// undefined symbols, as well as the number of each to put in the LC_DYSYMTAB
// load command.
-
for (std::vector<MachOSym>::iterator I = SymbolTable.begin(),
E = SymbolTable.end(); I != E; ++I) {
if (MachOSym::PartitionByLocal(*I)) {
@@ -427,10 +417,9 @@
++DySymTab.nundefsym;
}
}
-
+
// Write out a leading zero byte when emitting string table, for n_strx == 0
// which means an empty string.
-
OutputBuffer StrTOut(StrT, is64Bit, isLittleEndian);
StrTOut.outbyte(0);
@@ -439,7 +428,6 @@
// 2. strings for local symbols
// Since this is the opposite order from the symbol table, which we have just
// sorted, we can walk the symbol table backwards to output the string table.
-
for (std::vector<MachOSym>::reverse_iterator I = SymbolTable.rbegin(),
E = SymbolTable.rend(); I != E; ++I) {
if (I->GVName == "") {
@@ -463,7 +451,7 @@
I->n_value += GVSection[GV]->addr;
if (GV && (GVOffset[GV] == -1))
GVOffset[GV] = index;
-
+
// Emit nlist to buffer
SymTOut.outword(I->n_strx);
SymTOut.outbyte(I->n_type);
@@ -478,32 +466,29 @@
/// and the offset into that section. From this information, create the
/// appropriate target-specific MachORelocation type and add buffer it to be
/// written out after we are finished writing out sections.
-
void MachOWriter::CalculateRelocations(MachOSection &MOS) {
- for (unsigned i = 0, e = MOS.Relocations.size(); i != e; ++i) {
- MachineRelocation &MR = MOS.Relocations[i];
+ std::vector<MachineRelocation> Relocations = MOS.getRelocations();
+ for (unsigned i = 0, e = Relocations.size(); i != e; ++i) {
+ MachineRelocation &MR = Relocations[i];
unsigned TargetSection = MR.getConstantVal();
unsigned TargetAddr = 0;
unsigned TargetIndex = 0;
// 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
// points to the offset into the correct section.
-
if (MR.isGlobalValue()) {
GlobalValue *GV = MR.getGlobalValue();
MachOSection *MOSPtr = GVSection[GV];
intptr_t Offset = GVOffset[GV];
-
+
// If we have never seen the global before, it must be to a symbol
// defined in another module (N_UNDF).
-
if (!MOSPtr) {
// FIXME: need to append stub suffix
Extern = true;
@@ -515,10 +500,9 @@
}
MR.setResultPointer((void*)Offset);
}
-
+
// If the symbol is locally defined, pass in the address of the section and
// the section index to the code which will generate the target relocation.
-
if (!Extern) {
MachOSection &To = *SectionList[TargetSection - 1];
TargetAddr = To.addr;
@@ -526,7 +510,7 @@
}
OutputBuffer RelocOut(MOS.RelocBuffer, is64Bit, isLittleEndian);
- OutputBuffer SecOut(MOS.SectionData, is64Bit, isLittleEndian);
+ OutputBuffer SecOut(MOS.getData(), is64Bit, isLittleEndian);
MOS.nreloc += GetTargetRelocation(MR, MOS.Index, TargetAddr, TargetIndex,
RelocOut, SecOut, Scattered, Extern);
@@ -535,22 +519,21 @@
// InitMem - Write the value of a Constant to the specified memory location,
// converting it into bytes and relocations.
-
-void MachOWriter::InitMem(const Constant *C, void *Addr, intptr_t Offset,
- const TargetData *TD,
- std::vector<MachineRelocation> &MRs) {
+void MachOWriter::InitMem(const Constant *C, uintptr_t Offset,
+ const TargetData *TD, MachOSection* mos) {
typedef std::pair<const Constant*, intptr_t> CPair;
std::vector<CPair> WorkList;
-
+ uint8_t *Addr = &mos->getData()[0];
+
WorkList.push_back(CPair(C,(intptr_t)Addr + Offset));
-
+
intptr_t ScatteredOffset = 0;
-
+
while (!WorkList.empty()) {
const Constant *PC = WorkList.back().first;
intptr_t PA = WorkList.back().second;
WorkList.pop_back();
-
+
if (isa<UndefValue>(PC)) {
continue;
} else if (const ConstantVector *CP = dyn_cast<ConstantVector>(PC)) {
@@ -643,7 +626,7 @@
memset(ptr, 0, TD->getPointerSize());
else if (const GlobalValue* GV = dyn_cast<GlobalValue>(PC)) {
// FIXME: what about function stubs?
- MRs.push_back(MachineRelocation::getGV(PA-(intptr_t)Addr,
+ mos->addRelocation(MachineRelocation::getGV(PA-(intptr_t)Addr,
MachineRelocation::VANILLA,
const_cast<GlobalValue*>(GV),
ScatteredOffset));