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/MCStreamer.h"
17 #include "llvm/MC/MCAsmBackend.h"
18 #include "llvm/MC/MCAsmLayout.h"
19 #include "llvm/MC/MCAssembler.h"
20 #include "llvm/MC/MCCodeEmitter.h"
21 #include "llvm/MC/MCContext.h"
22 #include "llvm/MC/MCExpr.h"
23 #include "llvm/MC/MCObjectStreamer.h"
24 #include "llvm/MC/MCSection.h"
25 #include "llvm/MC/MCSectionCOFF.h"
26 #include "llvm/MC/MCSymbol.h"
27 #include "llvm/MC/MCValue.h"
28 #include "llvm/MC/MCWin64EH.h"
29 #include "llvm/Support/COFF.h"
30 #include "llvm/Support/Debug.h"
31 #include "llvm/Support/ErrorHandling.h"
32 #include "llvm/Support/TargetRegistry.h"
33 #include "llvm/Support/raw_ostream.h"
38 class WinCOFFStreamer : public MCObjectStreamer {
40 MCSymbol const *CurSymbol;
42 WinCOFFStreamer(MCContext &Context,
47 void AddCommonSymbol(MCSymbol *Symbol, uint64_t Size,
48 unsigned ByteAlignment, bool External);
50 // MCStreamer interface
52 virtual void InitSections();
53 virtual void InitToTextSection();
54 virtual void EmitLabel(MCSymbol *Symbol);
55 virtual void EmitDebugLabel(MCSymbol *Symbol);
56 virtual void EmitAssemblerFlag(MCAssemblerFlag Flag);
57 virtual void EmitThumbFunc(MCSymbol *Func);
58 virtual void EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute);
59 virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue);
60 virtual void BeginCOFFSymbolDef(MCSymbol const *Symbol);
61 virtual void EmitCOFFSymbolStorageClass(int StorageClass);
62 virtual void EmitCOFFSymbolType(int Type);
63 virtual void EndCOFFSymbolDef();
64 virtual void EmitCOFFSecRel32(MCSymbol const *Symbol);
65 virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value);
66 virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
67 unsigned ByteAlignment);
68 virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
69 unsigned ByteAlignment);
70 virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
71 uint64_t Size,unsigned ByteAlignment);
72 virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
73 uint64_t Size, unsigned ByteAlignment);
74 virtual void EmitFileDirective(StringRef Filename);
75 virtual void EmitWin64EHHandlerData();
76 virtual void FinishImpl();
79 virtual void EmitInstToData(const MCInst &Inst) {
80 MCDataFragment *DF = getOrCreateDataFragment();
82 SmallVector<MCFixup, 4> Fixups;
83 SmallString<256> Code;
84 raw_svector_ostream VecOS(Code);
85 getAssembler().getEmitter().EncodeInstruction(Inst, VecOS, Fixups);
88 // Add the fixups and data.
89 for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
90 Fixups[i].setOffset(Fixups[i].getOffset() + DF->getContents().size());
91 DF->getFixups().push_back(Fixups[i]);
93 DF->getContents().append(Code.begin(), Code.end());
96 void SetSection(StringRef Section,
97 unsigned Characteristics,
99 SwitchSection(getContext().getCOFFSection(Section, Characteristics, Kind));
102 void SetSectionText() {
104 COFF::IMAGE_SCN_CNT_CODE
105 | COFF::IMAGE_SCN_MEM_EXECUTE
106 | COFF::IMAGE_SCN_MEM_READ,
107 SectionKind::getText());
108 EmitCodeAlignment(4, 0);
111 void SetSectionData() {
113 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA
114 | COFF::IMAGE_SCN_MEM_READ
115 | COFF::IMAGE_SCN_MEM_WRITE,
116 SectionKind::getDataRel());
117 EmitCodeAlignment(4, 0);
120 void SetSectionBSS() {
122 COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA
123 | COFF::IMAGE_SCN_MEM_READ
124 | COFF::IMAGE_SCN_MEM_WRITE,
125 SectionKind::getBSS());
126 EmitCodeAlignment(4, 0);
129 } // end anonymous namespace.
131 WinCOFFStreamer::WinCOFFStreamer(MCContext &Context,
135 : MCObjectStreamer(Context, MAB, OS, &CE)
139 void WinCOFFStreamer::AddCommonSymbol(MCSymbol *Symbol, uint64_t Size,
140 unsigned ByteAlignment, bool External) {
141 assert(!Symbol->isInSection() && "Symbol must not already have a section!");
143 std::string SectionName(".bss$linkonce");
144 SectionName.append(Symbol->getName().begin(), Symbol->getName().end());
146 MCSymbolData &SymbolData = getAssembler().getOrCreateSymbolData(*Symbol);
148 unsigned Characteristics =
149 COFF::IMAGE_SCN_LNK_COMDAT |
150 COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
151 COFF::IMAGE_SCN_MEM_READ |
152 COFF::IMAGE_SCN_MEM_WRITE;
154 int Selection = COFF::IMAGE_COMDAT_SELECT_LARGEST;
156 const MCSection *Section = MCStreamer::getContext().getCOFFSection(
157 SectionName, Characteristics, Selection, SectionKind::getBSS());
159 MCSectionData &SectionData = getAssembler().getOrCreateSectionData(*Section);
161 if (SectionData.getAlignment() < ByteAlignment)
162 SectionData.setAlignment(ByteAlignment);
164 SymbolData.setExternal(External);
166 Symbol->setSection(*Section);
168 if (ByteAlignment != 1)
169 new MCAlignFragment(ByteAlignment, 0, 0, ByteAlignment, &SectionData);
171 SymbolData.setFragment(new MCFillFragment(0, 0, Size, &SectionData));
174 // MCStreamer interface
176 void WinCOFFStreamer::InitToTextSection() {
180 void WinCOFFStreamer::InitSections() {
187 void WinCOFFStreamer::EmitLabel(MCSymbol *Symbol) {
188 assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
189 MCObjectStreamer::EmitLabel(Symbol);
192 void WinCOFFStreamer::EmitDebugLabel(MCSymbol *Symbol) {
195 void WinCOFFStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
196 llvm_unreachable("not implemented");
199 void WinCOFFStreamer::EmitThumbFunc(MCSymbol *Func) {
200 llvm_unreachable("not implemented");
203 void WinCOFFStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
204 MCSymbolAttr Attribute) {
205 assert(Symbol && "Symbol must be non-null!");
206 assert((Symbol->isInSection()
207 ? Symbol->getSection().getVariant() == MCSection::SV_COFF
208 : true) && "Got non COFF section in the COFF backend!");
210 case MCSA_WeakReference:
212 MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
213 SD.modifyFlags(COFF::SF_WeakExternal, COFF::SF_WeakExternal);
214 SD.setExternal(true);
219 getAssembler().getOrCreateSymbolData(*Symbol).setExternal(true);
223 llvm_unreachable("unsupported attribute");
227 void WinCOFFStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
228 llvm_unreachable("not implemented");
231 void WinCOFFStreamer::BeginCOFFSymbolDef(MCSymbol const *Symbol) {
232 assert((Symbol->isInSection()
233 ? Symbol->getSection().getVariant() == MCSection::SV_COFF
234 : true) && "Got non COFF section in the COFF backend!");
235 assert(CurSymbol == NULL && "EndCOFFSymbolDef must be called between calls "
236 "to BeginCOFFSymbolDef!");
240 void WinCOFFStreamer::EmitCOFFSymbolStorageClass(int StorageClass) {
241 assert(CurSymbol != NULL && "BeginCOFFSymbolDef must be called first!");
242 assert((StorageClass & ~0xFF) == 0 && "StorageClass must only have data in "
245 getAssembler().getOrCreateSymbolData(*CurSymbol).modifyFlags(
246 StorageClass << COFF::SF_ClassShift,
250 void WinCOFFStreamer::EmitCOFFSymbolType(int Type) {
251 assert(CurSymbol != NULL && "BeginCOFFSymbolDef must be called first!");
252 assert((Type & ~0xFFFF) == 0 && "Type must only have data in the first 2 "
255 getAssembler().getOrCreateSymbolData(*CurSymbol).modifyFlags(
256 Type << COFF::SF_TypeShift,
260 void WinCOFFStreamer::EndCOFFSymbolDef() {
261 assert(CurSymbol != NULL && "BeginCOFFSymbolDef must be called first!");
265 void WinCOFFStreamer::EmitCOFFSecRel32(MCSymbol const *Symbol)
267 MCDataFragment *DF = getOrCreateDataFragment();
269 DF->getFixups().push_back(
270 MCFixup::Create(DF->getContents().size(),
271 MCSymbolRefExpr::Create (Symbol, getContext ()),
273 DF->getContents().resize(DF->getContents().size() + 4, 0);
276 void WinCOFFStreamer::EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
277 llvm_unreachable("not implemented");
280 void WinCOFFStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
281 unsigned ByteAlignment) {
282 assert((Symbol->isInSection()
283 ? Symbol->getSection().getVariant() == MCSection::SV_COFF
284 : true) && "Got non COFF section in the COFF backend!");
285 AddCommonSymbol(Symbol, Size, ByteAlignment, true);
288 void WinCOFFStreamer::EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
289 unsigned ByteAlignment) {
290 assert((Symbol->isInSection()
291 ? Symbol->getSection().getVariant() == MCSection::SV_COFF
292 : true) && "Got non COFF section in the COFF backend!");
293 AddCommonSymbol(Symbol, Size, ByteAlignment, false);
296 void WinCOFFStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
297 uint64_t Size,unsigned ByteAlignment) {
298 llvm_unreachable("not implemented");
301 void WinCOFFStreamer::EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
302 uint64_t Size, unsigned ByteAlignment) {
303 llvm_unreachable("not implemented");
306 void WinCOFFStreamer::EmitFileDirective(StringRef Filename) {
307 // Ignore for now, linkers don't care, and proper debug
308 // info will be a much large effort.
311 void WinCOFFStreamer::EmitWin64EHHandlerData() {
312 MCStreamer::EmitWin64EHHandlerData();
314 // We have to emit the unwind info now, because this directive
315 // actually switches to the .xdata section!
316 MCWin64EHUnwindEmitter::EmitUnwindInfo(*this, getCurrentW64UnwindInfo());
319 void WinCOFFStreamer::FinishImpl() {
321 MCObjectStreamer::FinishImpl();
326 MCStreamer *createWinCOFFStreamer(MCContext &Context,
331 WinCOFFStreamer *S = new WinCOFFStreamer(Context, MAB, CE, OS);
332 S->getAssembler().setRelaxAll(RelaxAll);