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 bool 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 EmitIdent(StringRef IdentString);
76 virtual void EmitWin64EHHandlerData();
77 virtual void FinishImpl();
80 virtual void EmitInstToData(const MCInst &Inst) {
81 MCDataFragment *DF = getOrCreateDataFragment();
83 SmallVector<MCFixup, 4> Fixups;
84 SmallString<256> Code;
85 raw_svector_ostream VecOS(Code);
86 getAssembler().getEmitter().EncodeInstruction(Inst, VecOS, Fixups);
89 // Add the fixups and data.
90 for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
91 Fixups[i].setOffset(Fixups[i].getOffset() + DF->getContents().size());
92 DF->getFixups().push_back(Fixups[i]);
94 DF->getContents().append(Code.begin(), Code.end());
97 void SetSection(StringRef Section,
98 unsigned Characteristics,
100 SwitchSection(getContext().getCOFFSection(Section, Characteristics, Kind));
103 void SetSectionText() {
105 COFF::IMAGE_SCN_CNT_CODE
106 | COFF::IMAGE_SCN_MEM_EXECUTE
107 | COFF::IMAGE_SCN_MEM_READ,
108 SectionKind::getText());
109 EmitCodeAlignment(4, 0);
112 void SetSectionData() {
114 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA
115 | COFF::IMAGE_SCN_MEM_READ
116 | COFF::IMAGE_SCN_MEM_WRITE,
117 SectionKind::getDataRel());
118 EmitCodeAlignment(4, 0);
121 void SetSectionBSS() {
123 COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA
124 | COFF::IMAGE_SCN_MEM_READ
125 | COFF::IMAGE_SCN_MEM_WRITE,
126 SectionKind::getBSS());
127 EmitCodeAlignment(4, 0);
130 } // end anonymous namespace.
132 WinCOFFStreamer::WinCOFFStreamer(MCContext &Context, MCAsmBackend &MAB,
133 MCCodeEmitter &CE, raw_ostream &OS)
134 : MCObjectStreamer(Context, 0, MAB, OS, &CE), CurSymbol(NULL) {}
136 void WinCOFFStreamer::AddCommonSymbol(MCSymbol *Symbol, uint64_t Size,
137 unsigned ByteAlignment, bool External) {
138 assert(!Symbol->isInSection() && "Symbol must not already have a section!");
140 std::string SectionName(".bss$linkonce");
141 SectionName.append(Symbol->getName().begin(), Symbol->getName().end());
143 MCSymbolData &SymbolData = getAssembler().getOrCreateSymbolData(*Symbol);
145 unsigned Characteristics =
146 COFF::IMAGE_SCN_LNK_COMDAT |
147 COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
148 COFF::IMAGE_SCN_MEM_READ |
149 COFF::IMAGE_SCN_MEM_WRITE;
151 int Selection = COFF::IMAGE_COMDAT_SELECT_LARGEST;
153 const MCSection *Section = MCStreamer::getContext().getCOFFSection(
154 SectionName, Characteristics, SectionKind::getBSS(), Selection);
156 MCSectionData &SectionData = getAssembler().getOrCreateSectionData(*Section);
158 if (SectionData.getAlignment() < ByteAlignment)
159 SectionData.setAlignment(ByteAlignment);
161 SymbolData.setExternal(External);
163 AssignSection(Symbol, Section);
165 if (ByteAlignment != 1)
166 new MCAlignFragment(ByteAlignment, 0, 0, ByteAlignment, &SectionData);
168 SymbolData.setFragment(new MCFillFragment(0, 0, Size, &SectionData));
171 // MCStreamer interface
173 void WinCOFFStreamer::InitToTextSection() {
177 void WinCOFFStreamer::InitSections() {
184 void WinCOFFStreamer::EmitLabel(MCSymbol *Symbol) {
185 assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
186 MCObjectStreamer::EmitLabel(Symbol);
189 void WinCOFFStreamer::EmitDebugLabel(MCSymbol *Symbol) {
192 void WinCOFFStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
193 llvm_unreachable("not implemented");
196 void WinCOFFStreamer::EmitThumbFunc(MCSymbol *Func) {
197 llvm_unreachable("not implemented");
200 bool WinCOFFStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
201 MCSymbolAttr Attribute) {
202 assert(Symbol && "Symbol must be non-null!");
203 assert((Symbol->isInSection()
204 ? Symbol->getSection().getVariant() == MCSection::SV_COFF
205 : true) && "Got non COFF section in the COFF backend!");
207 case MCSA_WeakReference:
209 MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
210 SD.modifyFlags(COFF::SF_WeakExternal, COFF::SF_WeakExternal);
211 SD.setExternal(true);
216 getAssembler().getOrCreateSymbolData(*Symbol).setExternal(true);
226 void WinCOFFStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
227 llvm_unreachable("not implemented");
230 void WinCOFFStreamer::BeginCOFFSymbolDef(MCSymbol const *Symbol) {
231 assert((Symbol->isInSection()
232 ? Symbol->getSection().getVariant() == MCSection::SV_COFF
233 : true) && "Got non COFF section in the COFF backend!");
234 assert(CurSymbol == NULL && "EndCOFFSymbolDef must be called between calls "
235 "to BeginCOFFSymbolDef!");
239 void WinCOFFStreamer::EmitCOFFSymbolStorageClass(int StorageClass) {
240 assert(CurSymbol != NULL && "BeginCOFFSymbolDef must be called first!");
241 assert((StorageClass & ~0xFF) == 0 && "StorageClass must only have data in "
244 getAssembler().getOrCreateSymbolData(*CurSymbol).modifyFlags(
245 StorageClass << COFF::SF_ClassShift,
249 void WinCOFFStreamer::EmitCOFFSymbolType(int Type) {
250 assert(CurSymbol != NULL && "BeginCOFFSymbolDef must be called first!");
251 assert((Type & ~0xFFFF) == 0 && "Type must only have data in the first 2 "
254 getAssembler().getOrCreateSymbolData(*CurSymbol).modifyFlags(
255 Type << COFF::SF_TypeShift,
259 void WinCOFFStreamer::EndCOFFSymbolDef() {
260 assert(CurSymbol != NULL && "BeginCOFFSymbolDef must be called first!");
264 void WinCOFFStreamer::EmitCOFFSecRel32(MCSymbol const *Symbol)
266 MCDataFragment *DF = getOrCreateDataFragment();
268 DF->getFixups().push_back(
269 MCFixup::Create(DF->getContents().size(),
270 MCSymbolRefExpr::Create (Symbol, getContext ()),
272 DF->getContents().resize(DF->getContents().size() + 4, 0);
275 void WinCOFFStreamer::EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
276 llvm_unreachable("not implemented");
279 void WinCOFFStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
280 unsigned ByteAlignment) {
281 assert((Symbol->isInSection()
282 ? Symbol->getSection().getVariant() == MCSection::SV_COFF
283 : true) && "Got non COFF section in the COFF backend!");
284 AddCommonSymbol(Symbol, Size, ByteAlignment, true);
287 void WinCOFFStreamer::EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
288 unsigned ByteAlignment) {
289 assert((Symbol->isInSection()
290 ? Symbol->getSection().getVariant() == MCSection::SV_COFF
291 : true) && "Got non COFF section in the COFF backend!");
292 AddCommonSymbol(Symbol, Size, ByteAlignment, false);
295 void WinCOFFStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
296 uint64_t Size,unsigned ByteAlignment) {
297 llvm_unreachable("not implemented");
300 void WinCOFFStreamer::EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
301 uint64_t Size, unsigned ByteAlignment) {
302 llvm_unreachable("not implemented");
305 void WinCOFFStreamer::EmitFileDirective(StringRef Filename) {
306 // Ignore for now, linkers don't care, and proper debug
307 // info will be a much large effort.
310 // TODO: Implement this if you want to emit .comment section in COFF obj files.
311 void WinCOFFStreamer::EmitIdent(StringRef IdentString) {
312 llvm_unreachable("unsupported directive");
315 void WinCOFFStreamer::EmitWin64EHHandlerData() {
316 MCStreamer::EmitWin64EHHandlerData();
318 // We have to emit the unwind info now, because this directive
319 // actually switches to the .xdata section!
320 MCWin64EHUnwindEmitter::EmitUnwindInfo(*this, getCurrentW64UnwindInfo());
323 void WinCOFFStreamer::FinishImpl() {
325 MCObjectStreamer::FinishImpl();
330 MCStreamer *createWinCOFFStreamer(MCContext &Context,
335 WinCOFFStreamer *S = new WinCOFFStreamer(Context, MAB, CE, OS);
336 S->getAssembler().setRelaxAll(RelaxAll);