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 EmitLabel(MCSymbol *Symbol);
52 virtual void EmitAssemblerFlag(MCAssemblerFlag Flag);
53 virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value);
54 virtual void EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute);
55 virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue);
56 virtual void BeginCOFFSymbolDef(MCSymbol const *Symbol);
57 virtual void EmitCOFFSymbolStorageClass(int StorageClass);
58 virtual void EmitCOFFSymbolType(int Type);
59 virtual void EndCOFFSymbolDef();
60 virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value);
61 virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
62 unsigned ByteAlignment);
63 virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size);
64 virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
65 unsigned Size,unsigned ByteAlignment);
66 virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
67 uint64_t Size, unsigned ByteAlignment);
68 virtual void EmitBytes(StringRef Data, unsigned AddrSpace);
69 virtual void EmitValue(const MCExpr *Value, unsigned Size,
71 virtual void EmitGPRel32Value(const MCExpr *Value);
72 virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value,
73 unsigned ValueSize, unsigned MaxBytesToEmit);
74 virtual void EmitCodeAlignment(unsigned ByteAlignment,
75 unsigned MaxBytesToEmit);
76 virtual void EmitValueToOffset(const MCExpr *Offset, unsigned char Value);
77 virtual void EmitFileDirective(StringRef Filename);
78 virtual void EmitDwarfFileDirective(unsigned FileNo,StringRef Filename);
79 virtual void EmitInstruction(const MCInst &Instruction);
80 virtual void Finish();
82 } // end anonymous namespace.
84 WinCOFFStreamer::WinCOFFStreamer(MCContext &Context,
85 TargetAsmBackend &TAB,
88 : MCObjectStreamer(Context, TAB, OS, &CE)
92 void WinCOFFStreamer::AddCommonSymbol(MCSymbol *Symbol, uint64_t Size,
93 unsigned ByteAlignment, bool External) {
94 assert(!Symbol->isInSection() && "Symbol must not already have a section!");
96 std::string SectionName(".bss$linkonce");
97 SectionName.append(Symbol->getName().begin(), Symbol->getName().end());
99 MCSymbolData &SymbolData = getAssembler().getOrCreateSymbolData(*Symbol);
101 unsigned Characteristics =
102 COFF::IMAGE_SCN_LNK_COMDAT |
103 COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
104 COFF::IMAGE_SCN_MEM_READ |
105 COFF::IMAGE_SCN_MEM_WRITE;
107 int Selection = COFF::IMAGE_COMDAT_SELECT_LARGEST;
109 const MCSection *Section = MCStreamer::getContext().getCOFFSection(
110 SectionName, Characteristics, Selection, SectionKind::getBSS());
112 MCSectionData &SectionData = getAssembler().getOrCreateSectionData(*Section);
114 if (SectionData.getAlignment() < ByteAlignment)
115 SectionData.setAlignment(ByteAlignment);
117 SymbolData.setExternal(External);
119 Symbol->setSection(*Section);
121 if (ByteAlignment != 1)
122 new MCAlignFragment(ByteAlignment, 0, 0, ByteAlignment, &SectionData);
124 SymbolData.setFragment(new MCFillFragment(0, 0, Size, &SectionData));
127 // MCStreamer interface
129 void WinCOFFStreamer::EmitLabel(MCSymbol *Symbol) {
130 // TODO: This is copied almost exactly from the MachOStreamer. Consider
131 // merging into MCObjectStreamer?
132 assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
133 assert(!Symbol->isVariable() && "Cannot emit a variable symbol!");
134 assert(CurSection && "Cannot emit before setting section!");
136 Symbol->setSection(*CurSection);
138 MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
140 // FIXME: This is wasteful, we don't necessarily need to create a data
141 // fragment. Instead, we should mark the symbol as pointing into the data
142 // fragment if it exists, otherwise we should just queue the label and set its
143 // fragment pointer when we emit the next fragment.
144 MCDataFragment *DF = getOrCreateDataFragment();
146 assert(!SD.getFragment() && "Unexpected fragment on symbol data!");
148 SD.setOffset(DF->getContents().size());
151 void WinCOFFStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
152 llvm_unreachable("not implemented");
155 void WinCOFFStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
156 // TODO: This is exactly the same as MachOStreamer. Consider merging into
158 getAssembler().getOrCreateSymbolData(*Symbol);
159 AddValueSymbols(Value);
160 Symbol->setVariableValue(Value);
163 void WinCOFFStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
164 MCSymbolAttr Attribute) {
166 case MCSA_WeakReference:
167 getAssembler().getOrCreateSymbolData(*Symbol).modifyFlags(
168 COFF::SF_WeakReference,
169 COFF::SF_WeakReference);
173 getAssembler().getOrCreateSymbolData(*Symbol).setExternal(true);
177 llvm_unreachable("unsupported attribute");
182 void WinCOFFStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
183 llvm_unreachable("not implemented");
186 void WinCOFFStreamer::BeginCOFFSymbolDef(MCSymbol const *Symbol) {
187 assert(CurSymbol == NULL && "EndCOFFSymbolDef must be called between calls "
188 "to BeginCOFFSymbolDef!");
192 void WinCOFFStreamer::EmitCOFFSymbolStorageClass(int StorageClass) {
193 assert(CurSymbol != NULL && "BeginCOFFSymbolDef must be called first!");
194 assert((StorageClass & ~0xFF) == 0 && "StorageClass must only have data in "
197 getAssembler().getOrCreateSymbolData(*CurSymbol).modifyFlags(
198 StorageClass << COFF::SF_ClassShift,
202 void WinCOFFStreamer::EmitCOFFSymbolType(int Type) {
203 assert(CurSymbol != NULL && "BeginCOFFSymbolDef must be called first!");
204 assert((Type & ~0xFFFF) == 0 && "Type must only have data in the first 2 "
207 getAssembler().getOrCreateSymbolData(*CurSymbol).modifyFlags(
208 Type << COFF::SF_TypeShift,
212 void WinCOFFStreamer::EndCOFFSymbolDef() {
213 assert(CurSymbol != NULL && "BeginCOFFSymbolDef must be called first!");
217 void WinCOFFStreamer::EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
218 llvm_unreachable("not implemented");
221 void WinCOFFStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
222 unsigned ByteAlignment) {
223 AddCommonSymbol(Symbol, Size, ByteAlignment, true);
226 void WinCOFFStreamer::EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size) {
227 AddCommonSymbol(Symbol, Size, 1, false);
230 void WinCOFFStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
231 unsigned Size,unsigned ByteAlignment) {
232 llvm_unreachable("not implemented");
235 void WinCOFFStreamer::EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
236 uint64_t Size, unsigned ByteAlignment) {
237 llvm_unreachable("not implemented");
240 void WinCOFFStreamer::EmitBytes(StringRef Data, unsigned AddrSpace) {
241 // TODO: This is copied exactly from the MachOStreamer. Consider merging into
243 getOrCreateDataFragment()->getContents().append(Data.begin(), Data.end());
246 void WinCOFFStreamer::EmitValue(const MCExpr *Value, unsigned Size,
247 unsigned AddrSpace) {
248 assert(AddrSpace == 0 && "Address space must be 0!");
250 // TODO: This is copied exactly from the MachOStreamer. Consider merging into
252 MCDataFragment *DF = getOrCreateDataFragment();
254 // Avoid fixups when possible.
256 if (AddValueSymbols(Value)->EvaluateAsAbsolute(AbsValue)) {
257 // FIXME: Endianness assumption.
258 for (unsigned i = 0; i != Size; ++i)
259 DF->getContents().push_back(uint8_t(AbsValue >> (i * 8)));
261 DF->addFixup(MCFixup::Create(DF->getContents().size(),
262 AddValueSymbols(Value),
263 MCFixup::getKindForSize(Size)));
264 DF->getContents().resize(DF->getContents().size() + Size, 0);
268 void WinCOFFStreamer::EmitGPRel32Value(const MCExpr *Value) {
269 llvm_unreachable("not implemented");
272 void WinCOFFStreamer::EmitValueToAlignment(unsigned ByteAlignment,
275 unsigned MaxBytesToEmit) {
276 // TODO: This is copied exactly from the MachOStreamer. Consider merging into
278 if (MaxBytesToEmit == 0)
279 MaxBytesToEmit = ByteAlignment;
280 new MCAlignFragment(ByteAlignment, Value, ValueSize, MaxBytesToEmit,
281 getCurrentSectionData());
283 // Update the maximum alignment on the current section if necessary.
284 if (ByteAlignment > getCurrentSectionData()->getAlignment())
285 getCurrentSectionData()->setAlignment(ByteAlignment);
288 void WinCOFFStreamer::EmitCodeAlignment(unsigned ByteAlignment,
289 unsigned MaxBytesToEmit) {
290 // TODO: This is copied exactly from the MachOStreamer. Consider merging into
292 if (MaxBytesToEmit == 0)
293 MaxBytesToEmit = ByteAlignment;
294 MCAlignFragment *F = new MCAlignFragment(ByteAlignment, 0, 1, MaxBytesToEmit,
295 getCurrentSectionData());
296 F->setEmitNops(true);
298 // Update the maximum alignment on the current section if necessary.
299 if (ByteAlignment > getCurrentSectionData()->getAlignment())
300 getCurrentSectionData()->setAlignment(ByteAlignment);
303 void WinCOFFStreamer::EmitValueToOffset(const MCExpr *Offset,
304 unsigned char Value) {
305 llvm_unreachable("not implemented");
308 void WinCOFFStreamer::EmitFileDirective(StringRef Filename) {
309 // Ignore for now, linkers don't care, and proper debug
310 // info will be a much large effort.
313 void WinCOFFStreamer::EmitDwarfFileDirective(unsigned FileNo,
314 StringRef Filename) {
315 llvm_unreachable("not implemented");
318 void WinCOFFStreamer::EmitInstruction(const MCInst &Instruction) {
319 for (unsigned i = 0, e = Instruction.getNumOperands(); i != e; ++i)
320 if (Instruction.getOperand(i).isExpr())
321 AddValueSymbols(Instruction.getOperand(i).getExpr());
323 getCurrentSectionData()->setHasInstructions(true);
325 MCInstFragment *Fragment =
326 new MCInstFragment(Instruction, getCurrentSectionData());
328 raw_svector_ostream VecOS(Fragment->getCode());
330 getAssembler().getEmitter().EncodeInstruction(Instruction, VecOS,
331 Fragment->getFixups());
334 void WinCOFFStreamer::Finish() {
335 MCObjectStreamer::Finish();
340 MCStreamer *createWinCOFFStreamer(MCContext &Context,
341 TargetAsmBackend &TAB,
345 WinCOFFStreamer *S = new WinCOFFStreamer(Context, TAB, CE, OS);
346 S->getAssembler().setRelaxAll(RelaxAll);