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 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, MCAsmBackend &MAB,
132 MCCodeEmitter &CE, raw_ostream &OS)
133 : MCObjectStreamer(Context, MAB, OS, &CE), CurSymbol(NULL) {}
135 void WinCOFFStreamer::AddCommonSymbol(MCSymbol *Symbol, uint64_t Size,
136 unsigned ByteAlignment, bool External) {
137 assert(!Symbol->isInSection() && "Symbol must not already have a section!");
139 std::string SectionName(".bss$linkonce");
140 SectionName.append(Symbol->getName().begin(), Symbol->getName().end());
142 MCSymbolData &SymbolData = getAssembler().getOrCreateSymbolData(*Symbol);
144 unsigned Characteristics =
145 COFF::IMAGE_SCN_LNK_COMDAT |
146 COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
147 COFF::IMAGE_SCN_MEM_READ |
148 COFF::IMAGE_SCN_MEM_WRITE;
150 int Selection = COFF::IMAGE_COMDAT_SELECT_LARGEST;
152 const MCSection *Section = MCStreamer::getContext().getCOFFSection(
153 SectionName, Characteristics, SectionKind::getBSS(), Selection);
155 MCSectionData &SectionData = getAssembler().getOrCreateSectionData(*Section);
157 if (SectionData.getAlignment() < ByteAlignment)
158 SectionData.setAlignment(ByteAlignment);
160 SymbolData.setExternal(External);
162 AssignSection(Symbol, Section);
164 if (ByteAlignment != 1)
165 new MCAlignFragment(ByteAlignment, 0, 0, ByteAlignment, &SectionData);
167 SymbolData.setFragment(new MCFillFragment(0, 0, Size, &SectionData));
170 // MCStreamer interface
172 void WinCOFFStreamer::InitToTextSection() {
176 void WinCOFFStreamer::InitSections() {
183 void WinCOFFStreamer::EmitLabel(MCSymbol *Symbol) {
184 assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
185 MCObjectStreamer::EmitLabel(Symbol);
188 void WinCOFFStreamer::EmitDebugLabel(MCSymbol *Symbol) {
191 void WinCOFFStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
192 llvm_unreachable("not implemented");
195 void WinCOFFStreamer::EmitThumbFunc(MCSymbol *Func) {
196 llvm_unreachable("not implemented");
199 bool WinCOFFStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
200 MCSymbolAttr Attribute) {
201 assert(Symbol && "Symbol must be non-null!");
202 assert((Symbol->isInSection()
203 ? Symbol->getSection().getVariant() == MCSection::SV_COFF
204 : true) && "Got non COFF section in the COFF backend!");
206 case MCSA_WeakReference:
208 MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
209 SD.modifyFlags(COFF::SF_WeakExternal, COFF::SF_WeakExternal);
210 SD.setExternal(true);
215 getAssembler().getOrCreateSymbolData(*Symbol).setExternal(true);
225 void WinCOFFStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
226 llvm_unreachable("not implemented");
229 void WinCOFFStreamer::BeginCOFFSymbolDef(MCSymbol const *Symbol) {
230 assert((Symbol->isInSection()
231 ? Symbol->getSection().getVariant() == MCSection::SV_COFF
232 : true) && "Got non COFF section in the COFF backend!");
233 assert(CurSymbol == NULL && "EndCOFFSymbolDef must be called between calls "
234 "to BeginCOFFSymbolDef!");
238 void WinCOFFStreamer::EmitCOFFSymbolStorageClass(int StorageClass) {
239 assert(CurSymbol != NULL && "BeginCOFFSymbolDef must be called first!");
240 assert((StorageClass & ~0xFF) == 0 && "StorageClass must only have data in "
243 getAssembler().getOrCreateSymbolData(*CurSymbol).modifyFlags(
244 StorageClass << COFF::SF_ClassShift,
248 void WinCOFFStreamer::EmitCOFFSymbolType(int Type) {
249 assert(CurSymbol != NULL && "BeginCOFFSymbolDef must be called first!");
250 assert((Type & ~0xFFFF) == 0 && "Type must only have data in the first 2 "
253 getAssembler().getOrCreateSymbolData(*CurSymbol).modifyFlags(
254 Type << COFF::SF_TypeShift,
258 void WinCOFFStreamer::EndCOFFSymbolDef() {
259 assert(CurSymbol != NULL && "BeginCOFFSymbolDef must be called first!");
263 void WinCOFFStreamer::EmitCOFFSecRel32(MCSymbol const *Symbol)
265 MCDataFragment *DF = getOrCreateDataFragment();
267 DF->getFixups().push_back(
268 MCFixup::Create(DF->getContents().size(),
269 MCSymbolRefExpr::Create (Symbol, getContext ()),
271 DF->getContents().resize(DF->getContents().size() + 4, 0);
274 void WinCOFFStreamer::EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
275 llvm_unreachable("not implemented");
278 void WinCOFFStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
279 unsigned ByteAlignment) {
280 assert((Symbol->isInSection()
281 ? Symbol->getSection().getVariant() == MCSection::SV_COFF
282 : true) && "Got non COFF section in the COFF backend!");
283 AddCommonSymbol(Symbol, Size, ByteAlignment, true);
286 void WinCOFFStreamer::EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
287 unsigned ByteAlignment) {
288 assert((Symbol->isInSection()
289 ? Symbol->getSection().getVariant() == MCSection::SV_COFF
290 : true) && "Got non COFF section in the COFF backend!");
291 AddCommonSymbol(Symbol, Size, ByteAlignment, false);
294 void WinCOFFStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
295 uint64_t Size,unsigned ByteAlignment) {
296 llvm_unreachable("not implemented");
299 void WinCOFFStreamer::EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
300 uint64_t Size, unsigned ByteAlignment) {
301 llvm_unreachable("not implemented");
304 void WinCOFFStreamer::EmitFileDirective(StringRef Filename) {
305 // Ignore for now, linkers don't care, and proper debug
306 // info will be a much large effort.
309 void WinCOFFStreamer::EmitWin64EHHandlerData() {
310 MCStreamer::EmitWin64EHHandlerData();
312 // We have to emit the unwind info now, because this directive
313 // actually switches to the .xdata section!
314 MCWin64EHUnwindEmitter::EmitUnwindInfo(*this, getCurrentW64UnwindInfo());
317 void WinCOFFStreamer::FinishImpl() {
319 MCObjectStreamer::FinishImpl();
324 MCStreamer *createWinCOFFStreamer(MCContext &Context,
329 WinCOFFStreamer *S = new WinCOFFStreamer(Context, MAB, CE, OS);
330 S->getAssembler().setRelaxAll(RelaxAll);