1 //===- lib/MC/MCPureStreamer.cpp - MC "Pure" Object Output ----------------===//
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 #include "llvm/MC/MCStreamer.h"
11 #include "llvm/MC/MCAssembler.h"
12 #include "llvm/MC/MCCodeEmitter.h"
13 #include "llvm/MC/MCContext.h"
14 #include "llvm/MC/MCExpr.h"
15 #include "llvm/MC/MCObjectFileInfo.h"
16 #include "llvm/MC/MCObjectStreamer.h"
17 #include "llvm/MC/MCSymbol.h"
18 #include "llvm/Support/ErrorHandling.h"
24 class MCPureStreamer : public MCObjectStreamer {
26 virtual void EmitInstToFragment(const MCInst &Inst,
27 const MCSubtargetInfo &STI);
28 virtual void EmitInstToData(const MCInst &Inst, const MCSubtargetInfo &STI);
31 MCPureStreamer(MCContext &Context, MCAsmBackend &TAB, raw_ostream &OS,
32 MCCodeEmitter *Emitter)
33 : MCObjectStreamer(Context, TAB, OS, Emitter) {}
35 /// @name MCStreamer Interface
38 virtual void EmitLabel(MCSymbol *Symbol);
39 virtual void EmitDebugLabel(MCSymbol *Symbol);
40 virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
41 uint64_t Size = 0, unsigned ByteAlignment = 0);
42 virtual void EmitBytes(StringRef Data);
43 virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
44 unsigned ValueSize = 1,
45 unsigned MaxBytesToEmit = 0);
46 virtual void EmitCodeAlignment(unsigned ByteAlignment,
47 unsigned MaxBytesToEmit = 0);
48 virtual bool EmitValueToOffset(const MCExpr *Offset,
49 unsigned char Value = 0);
50 virtual void FinishImpl();
53 virtual bool EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute) {
54 report_fatal_error("unsupported directive in pure streamer");
57 virtual void EmitAssemblerFlag(MCAssemblerFlag Flag) {
58 report_fatal_error("unsupported directive in pure streamer");
60 virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
61 uint64_t Size, unsigned ByteAlignment = 0) {
62 report_fatal_error("unsupported directive in pure streamer");
64 virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
65 report_fatal_error("unsupported directive in pure streamer");
67 virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
68 unsigned ByteAlignment) {
69 report_fatal_error("unsupported directive in pure streamer");
71 virtual void EmitThumbFunc(MCSymbol *Func) {
72 report_fatal_error("unsupported directive in pure streamer");
74 virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol) {
75 report_fatal_error("unsupported directive in pure streamer");
77 virtual void EmitCOFFSymbolStorageClass(int StorageClass) {
78 report_fatal_error("unsupported directive in pure streamer");
80 virtual void EmitCOFFSymbolType(int Type) {
81 report_fatal_error("unsupported directive in pure streamer");
83 virtual void EndCOFFSymbolDef() {
84 report_fatal_error("unsupported directive in pure streamer");
86 virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
87 report_fatal_error("unsupported directive in pure streamer");
89 virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
90 unsigned ByteAlignment) {
91 report_fatal_error("unsupported directive in pure streamer");
93 virtual void EmitFileDirective(StringRef Filename) {
94 report_fatal_error("unsupported directive in pure streamer");
96 virtual void EmitIdent(StringRef IdentString) {
97 report_fatal_error("unsupported directive in pure streamer");
99 virtual bool EmitDwarfFileDirective(unsigned FileNo, StringRef Directory,
100 StringRef Filename, unsigned CUID = 0) {
101 report_fatal_error("unsupported directive in pure streamer");
105 } // end anonymous namespace.
107 void MCPureStreamer::EmitLabel(MCSymbol *Symbol) {
108 assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
109 assert(!Symbol->isVariable() && "Cannot emit a variable symbol!");
110 assert(getCurrentSection().first && "Cannot emit before setting section!");
112 AssignSection(Symbol, getCurrentSection().first);
114 MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
116 // We have to create a new fragment if this is an atom defining symbol,
117 // fragments cannot span atoms.
118 if (getAssembler().isSymbolLinkerVisible(SD.getSymbol()))
119 insert(new MCDataFragment());
121 // FIXME: This is wasteful, we don't necessarily need to create a data
122 // fragment. Instead, we should mark the symbol as pointing into the data
123 // fragment if it exists, otherwise we should just queue the label and set its
124 // fragment pointer when we emit the next fragment.
125 MCDataFragment *F = getOrCreateDataFragment();
126 assert(!SD.getFragment() && "Unexpected fragment on symbol data!");
128 SD.setOffset(F->getContents().size());
132 void MCPureStreamer::EmitDebugLabel(MCSymbol *Symbol) {
136 void MCPureStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
137 uint64_t Size, unsigned ByteAlignment) {
138 report_fatal_error("not yet implemented in pure streamer");
141 void MCPureStreamer::EmitBytes(StringRef Data) {
142 // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
144 getOrCreateDataFragment()->getContents().append(Data.begin(), Data.end());
147 void MCPureStreamer::EmitValueToAlignment(unsigned ByteAlignment,
148 int64_t Value, unsigned ValueSize,
149 unsigned MaxBytesToEmit) {
150 // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
152 if (MaxBytesToEmit == 0)
153 MaxBytesToEmit = ByteAlignment;
154 insert(new MCAlignFragment(ByteAlignment, Value, ValueSize, MaxBytesToEmit));
156 // Update the maximum alignment on the current section if necessary.
157 if (ByteAlignment > getCurrentSectionData()->getAlignment())
158 getCurrentSectionData()->setAlignment(ByteAlignment);
161 void MCPureStreamer::EmitCodeAlignment(unsigned ByteAlignment,
162 unsigned MaxBytesToEmit) {
163 // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
165 if (MaxBytesToEmit == 0)
166 MaxBytesToEmit = ByteAlignment;
167 MCAlignFragment *F = new MCAlignFragment(ByteAlignment, 0, 1, MaxBytesToEmit);
169 F->setEmitNops(true);
171 // Update the maximum alignment on the current section if necessary.
172 if (ByteAlignment > getCurrentSectionData()->getAlignment())
173 getCurrentSectionData()->setAlignment(ByteAlignment);
176 bool MCPureStreamer::EmitValueToOffset(const MCExpr *Offset,
177 unsigned char Value) {
178 insert(new MCOrgFragment(*Offset, Value));
182 void MCPureStreamer::EmitInstToFragment(const MCInst &Inst,
183 const MCSubtargetInfo &STI) {
184 MCRelaxableFragment *IF = new MCRelaxableFragment(Inst, STI);
187 // Add the fixups and data.
189 // FIXME: Revisit this design decision when relaxation is done, we may be
190 // able to get away with not storing any extra data in the MCInst.
191 SmallVector<MCFixup, 4> Fixups;
192 SmallString<256> Code;
193 raw_svector_ostream VecOS(Code);
194 getAssembler().getEmitter().EncodeInstruction(Inst, VecOS, Fixups, STI);
197 IF->getContents() = Code;
198 IF->getFixups() = Fixups;
201 void MCPureStreamer::EmitInstToData(const MCInst &Inst,
202 const MCSubtargetInfo &STI) {
203 MCDataFragment *DF = getOrCreateDataFragment();
205 SmallVector<MCFixup, 4> Fixups;
206 SmallString<256> Code;
207 raw_svector_ostream VecOS(Code);
208 getAssembler().getEmitter().EncodeInstruction(Inst, VecOS, Fixups, STI);
211 // Add the fixups and data.
212 for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
213 Fixups[i].setOffset(Fixups[i].getOffset() + DF->getContents().size());
214 DF->getFixups().push_back(Fixups[i]);
216 DF->getContents().append(Code.begin(), Code.end());
219 void MCPureStreamer::FinishImpl() {
220 // FIXME: Handle DWARF tables?
222 this->MCObjectStreamer::FinishImpl();
225 MCStreamer *llvm::createPureStreamer(MCContext &Context, MCAsmBackend &MAB,
226 raw_ostream &OS, MCCodeEmitter *CE) {
227 return new MCPureStreamer(Context, MAB, OS, CE);