1 //===-- llvm/MC/WinCOFFStreamer.cpp -----------------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains an implementation of a Win32 COFF object file streamer.
12 //===----------------------------------------------------------------------===//
14 #define DEBUG_TYPE "WinCOFFStreamer"
16 #include "llvm/MC/MCObjectStreamer.h"
17 #include "llvm/MC/MCContext.h"
18 #include "llvm/MC/MCSection.h"
19 #include "llvm/MC/MCSymbol.h"
20 #include "llvm/MC/MCExpr.h"
21 #include "llvm/MC/MCValue.h"
22 #include "llvm/MC/MCAssembler.h"
23 #include "llvm/MC/MCAsmLayout.h"
24 #include "llvm/MC/MCCodeEmitter.h"
25 #include "llvm/MC/MCSectionCOFF.h"
26 #include "llvm/Target/TargetRegistry.h"
27 #include "llvm/Target/TargetAsmBackend.h"
28 #include "llvm/ADT/StringMap.h"
30 #include "llvm/Support/COFF.h"
31 #include "llvm/Support/Debug.h"
32 #include "llvm/Support/ErrorHandling.h"
33 #include "llvm/Support/raw_ostream.h"
37 class WinCOFFStreamer : public MCObjectStreamer {
39 MCSymbol const *CurSymbol;
41 WinCOFFStreamer(MCContext &Context,
42 TargetAsmBackend &TAB,
46 void AddCommonSymbol(MCSymbol *Symbol, uint64_t Size,
47 unsigned ByteAlignment, bool External);
49 // MCStreamer interface
51 virtual void InitSections();
52 virtual void EmitLabel(MCSymbol *Symbol);
53 virtual void EmitAssemblerFlag(MCAssemblerFlag Flag);
54 virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value);
55 virtual void EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute);
56 virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue);
57 virtual void BeginCOFFSymbolDef(MCSymbol const *Symbol);
58 virtual void EmitCOFFSymbolStorageClass(int StorageClass);
59 virtual void EmitCOFFSymbolType(int Type);
60 virtual void EndCOFFSymbolDef();
61 virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value);
62 virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
63 unsigned ByteAlignment);
64 virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size);
65 virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
66 unsigned Size,unsigned ByteAlignment);
67 virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
68 uint64_t Size, unsigned ByteAlignment);
69 virtual void EmitBytes(StringRef Data, unsigned AddrSpace);
70 virtual void EmitValue(const MCExpr *Value, unsigned Size,
72 virtual void EmitGPRel32Value(const MCExpr *Value);
73 virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value,
74 unsigned ValueSize, unsigned MaxBytesToEmit);
75 virtual void EmitCodeAlignment(unsigned ByteAlignment,
76 unsigned MaxBytesToEmit);
77 virtual void EmitValueToOffset(const MCExpr *Offset, unsigned char Value);
78 virtual void EmitFileDirective(StringRef Filename);
79 virtual void EmitDwarfFileDirective(unsigned FileNo,StringRef Filename);
80 virtual void EmitInstruction(const MCInst &Instruction);
81 virtual void Finish();
83 } // end anonymous namespace.
85 WinCOFFStreamer::WinCOFFStreamer(MCContext &Context,
86 TargetAsmBackend &TAB,
89 : MCObjectStreamer(Context, TAB, OS, &CE)
93 void WinCOFFStreamer::AddCommonSymbol(MCSymbol *Symbol, uint64_t Size,
94 unsigned ByteAlignment, bool External) {
95 assert(!Symbol->isInSection() && "Symbol must not already have a section!");
97 std::string SectionName(".bss$linkonce");
98 SectionName.append(Symbol->getName().begin(), Symbol->getName().end());
100 MCSymbolData &SymbolData = getAssembler().getOrCreateSymbolData(*Symbol);
102 unsigned Characteristics =
103 COFF::IMAGE_SCN_LNK_COMDAT |
104 COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
105 COFF::IMAGE_SCN_MEM_READ |
106 COFF::IMAGE_SCN_MEM_WRITE;
108 int Selection = COFF::IMAGE_COMDAT_SELECT_LARGEST;
110 const MCSection *Section = MCStreamer::getContext().getCOFFSection(
111 SectionName, Characteristics, Selection, SectionKind::getBSS());
113 MCSectionData &SectionData = getAssembler().getOrCreateSectionData(*Section);
115 if (SectionData.getAlignment() < ByteAlignment)
116 SectionData.setAlignment(ByteAlignment);
118 SymbolData.setExternal(External);
120 Symbol->setSection(*Section);
122 if (ByteAlignment != 1)
123 new MCAlignFragment(ByteAlignment, 0, 0, ByteAlignment, &SectionData);
125 SymbolData.setFragment(new MCFillFragment(0, 0, Size, &SectionData));
128 // MCStreamer interface
130 void WinCOFFStreamer::InitSections() {
133 void WinCOFFStreamer::EmitLabel(MCSymbol *Symbol) {
134 // TODO: This is copied almost exactly from the MachOStreamer. Consider
135 // merging into MCObjectStreamer?
136 assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
137 assert(!Symbol->isVariable() && "Cannot emit a variable symbol!");
138 assert(CurSection && "Cannot emit before setting section!");
140 Symbol->setSection(*CurSection);
142 MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
144 // FIXME: This is wasteful, we don't necessarily need to create a data
145 // fragment. Instead, we should mark the symbol as pointing into the data
146 // fragment if it exists, otherwise we should just queue the label and set its
147 // fragment pointer when we emit the next fragment.
148 MCDataFragment *DF = getOrCreateDataFragment();
150 assert(!SD.getFragment() && "Unexpected fragment on symbol data!");
152 SD.setOffset(DF->getContents().size());
155 void WinCOFFStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
156 llvm_unreachable("not implemented");
159 void WinCOFFStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
160 // TODO: This is exactly the same as MachOStreamer. Consider merging into
162 getAssembler().getOrCreateSymbolData(*Symbol);
163 AddValueSymbols(Value);
164 Symbol->setVariableValue(Value);
167 void WinCOFFStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
168 MCSymbolAttr Attribute) {
170 case MCSA_WeakReference:
171 getAssembler().getOrCreateSymbolData(*Symbol).modifyFlags(
172 COFF::SF_WeakReference,
173 COFF::SF_WeakReference);
177 getAssembler().getOrCreateSymbolData(*Symbol).setExternal(true);
181 llvm_unreachable("unsupported attribute");
186 void WinCOFFStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
187 llvm_unreachable("not implemented");
190 void WinCOFFStreamer::BeginCOFFSymbolDef(MCSymbol const *Symbol) {
191 assert(CurSymbol == NULL && "EndCOFFSymbolDef must be called between calls "
192 "to BeginCOFFSymbolDef!");
196 void WinCOFFStreamer::EmitCOFFSymbolStorageClass(int StorageClass) {
197 assert(CurSymbol != NULL && "BeginCOFFSymbolDef must be called first!");
198 assert((StorageClass & ~0xFF) == 0 && "StorageClass must only have data in "
201 getAssembler().getOrCreateSymbolData(*CurSymbol).modifyFlags(
202 StorageClass << COFF::SF_ClassShift,
206 void WinCOFFStreamer::EmitCOFFSymbolType(int Type) {
207 assert(CurSymbol != NULL && "BeginCOFFSymbolDef must be called first!");
208 assert((Type & ~0xFFFF) == 0 && "Type must only have data in the first 2 "
211 getAssembler().getOrCreateSymbolData(*CurSymbol).modifyFlags(
212 Type << COFF::SF_TypeShift,
216 void WinCOFFStreamer::EndCOFFSymbolDef() {
217 assert(CurSymbol != NULL && "BeginCOFFSymbolDef must be called first!");
221 void WinCOFFStreamer::EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
222 llvm_unreachable("not implemented");
225 void WinCOFFStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
226 unsigned ByteAlignment) {
227 AddCommonSymbol(Symbol, Size, ByteAlignment, true);
230 void WinCOFFStreamer::EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size) {
231 AddCommonSymbol(Symbol, Size, 1, false);
234 void WinCOFFStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
235 unsigned Size,unsigned ByteAlignment) {
236 llvm_unreachable("not implemented");
239 void WinCOFFStreamer::EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
240 uint64_t Size, unsigned ByteAlignment) {
241 llvm_unreachable("not implemented");
244 void WinCOFFStreamer::EmitBytes(StringRef Data, unsigned AddrSpace) {
245 // TODO: This is copied exactly from the MachOStreamer. Consider merging into
247 getOrCreateDataFragment()->getContents().append(Data.begin(), Data.end());
250 void WinCOFFStreamer::EmitValue(const MCExpr *Value, unsigned Size,
251 unsigned AddrSpace) {
252 assert(AddrSpace == 0 && "Address space must be 0!");
254 // TODO: This is copied exactly from the MachOStreamer. Consider merging into
256 MCDataFragment *DF = getOrCreateDataFragment();
258 // Avoid fixups when possible.
260 if (AddValueSymbols(Value)->EvaluateAsAbsolute(AbsValue)) {
261 // FIXME: Endianness assumption.
262 for (unsigned i = 0; i != Size; ++i)
263 DF->getContents().push_back(uint8_t(AbsValue >> (i * 8)));
265 DF->addFixup(MCFixup::Create(DF->getContents().size(),
266 AddValueSymbols(Value),
267 MCFixup::getKindForSize(Size)));
268 DF->getContents().resize(DF->getContents().size() + Size, 0);
272 void WinCOFFStreamer::EmitGPRel32Value(const MCExpr *Value) {
273 llvm_unreachable("not implemented");
276 void WinCOFFStreamer::EmitValueToAlignment(unsigned ByteAlignment,
279 unsigned MaxBytesToEmit) {
280 // TODO: This is copied exactly from the MachOStreamer. Consider merging into
282 if (MaxBytesToEmit == 0)
283 MaxBytesToEmit = ByteAlignment;
284 new MCAlignFragment(ByteAlignment, Value, ValueSize, MaxBytesToEmit,
285 getCurrentSectionData());
287 // Update the maximum alignment on the current section if necessary.
288 if (ByteAlignment > getCurrentSectionData()->getAlignment())
289 getCurrentSectionData()->setAlignment(ByteAlignment);
292 void WinCOFFStreamer::EmitCodeAlignment(unsigned ByteAlignment,
293 unsigned MaxBytesToEmit) {
294 // TODO: This is copied exactly from the MachOStreamer. Consider merging into
296 if (MaxBytesToEmit == 0)
297 MaxBytesToEmit = ByteAlignment;
298 MCAlignFragment *F = new MCAlignFragment(ByteAlignment, 0, 1, MaxBytesToEmit,
299 getCurrentSectionData());
300 F->setEmitNops(true);
302 // Update the maximum alignment on the current section if necessary.
303 if (ByteAlignment > getCurrentSectionData()->getAlignment())
304 getCurrentSectionData()->setAlignment(ByteAlignment);
307 void WinCOFFStreamer::EmitValueToOffset(const MCExpr *Offset,
308 unsigned char Value) {
309 llvm_unreachable("not implemented");
312 void WinCOFFStreamer::EmitFileDirective(StringRef Filename) {
313 // Ignore for now, linkers don't care, and proper debug
314 // info will be a much large effort.
317 void WinCOFFStreamer::EmitDwarfFileDirective(unsigned FileNo,
318 StringRef Filename) {
319 llvm_unreachable("not implemented");
322 void WinCOFFStreamer::EmitInstruction(const MCInst &Instruction) {
323 for (unsigned i = 0, e = Instruction.getNumOperands(); i != e; ++i)
324 if (Instruction.getOperand(i).isExpr())
325 AddValueSymbols(Instruction.getOperand(i).getExpr());
327 getCurrentSectionData()->setHasInstructions(true);
329 MCInstFragment *Fragment =
330 new MCInstFragment(Instruction, getCurrentSectionData());
332 raw_svector_ostream VecOS(Fragment->getCode());
334 getAssembler().getEmitter().EncodeInstruction(Instruction, VecOS,
335 Fragment->getFixups());
338 void WinCOFFStreamer::Finish() {
339 MCObjectStreamer::Finish();
344 MCStreamer *createWinCOFFStreamer(MCContext &Context,
345 TargetAsmBackend &TAB,
349 WinCOFFStreamer *S = new WinCOFFStreamer(Context, TAB, CE, OS);
350 S->getAssembler().setRelaxAll(RelaxAll);