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 virtual void EmitInstToData(const MCInst &Inst);
30 MCPureStreamer(MCContext &Context, MCAsmBackend &TAB, raw_ostream &OS,
31 MCCodeEmitter *Emitter)
32 : MCObjectStreamer(Context, 0, TAB, OS, Emitter) {}
34 /// @name MCStreamer Interface
37 virtual void EmitLabel(MCSymbol *Symbol);
38 virtual void EmitDebugLabel(MCSymbol *Symbol);
39 virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
40 uint64_t Size = 0, unsigned ByteAlignment = 0);
41 virtual void EmitBytes(StringRef Data);
42 virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
43 unsigned ValueSize = 1,
44 unsigned MaxBytesToEmit = 0);
45 virtual void EmitCodeAlignment(unsigned ByteAlignment,
46 unsigned MaxBytesToEmit = 0);
47 virtual bool EmitValueToOffset(const MCExpr *Offset,
48 unsigned char Value = 0);
49 virtual void FinishImpl();
52 virtual bool EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute) {
53 report_fatal_error("unsupported directive in pure streamer");
56 virtual void EmitAssemblerFlag(MCAssemblerFlag Flag) {
57 report_fatal_error("unsupported directive in pure streamer");
59 virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
60 uint64_t Size, unsigned ByteAlignment = 0) {
61 report_fatal_error("unsupported directive in pure streamer");
63 virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
64 report_fatal_error("unsupported directive in pure streamer");
66 virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
67 unsigned ByteAlignment) {
68 report_fatal_error("unsupported directive in pure streamer");
70 virtual void EmitThumbFunc(MCSymbol *Func) {
71 report_fatal_error("unsupported directive in pure streamer");
73 virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol) {
74 report_fatal_error("unsupported directive in pure streamer");
76 virtual void EmitCOFFSymbolStorageClass(int StorageClass) {
77 report_fatal_error("unsupported directive in pure streamer");
79 virtual void EmitCOFFSymbolType(int Type) {
80 report_fatal_error("unsupported directive in pure streamer");
82 virtual void EndCOFFSymbolDef() {
83 report_fatal_error("unsupported directive in pure streamer");
85 virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
86 report_fatal_error("unsupported directive in pure streamer");
88 virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
89 unsigned ByteAlignment) {
90 report_fatal_error("unsupported directive in pure streamer");
92 virtual void EmitFileDirective(StringRef Filename) {
93 report_fatal_error("unsupported directive in pure streamer");
95 virtual void EmitIdent(StringRef IdentString) {
96 report_fatal_error("unsupported directive in pure streamer");
98 virtual bool EmitDwarfFileDirective(unsigned FileNo, StringRef Directory,
99 StringRef Filename, unsigned CUID = 0) {
100 report_fatal_error("unsupported directive in pure streamer");
104 } // end anonymous namespace.
106 void MCPureStreamer::EmitLabel(MCSymbol *Symbol) {
107 assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
108 assert(!Symbol->isVariable() && "Cannot emit a variable symbol!");
109 assert(getCurrentSection().first && "Cannot emit before setting section!");
111 AssignSection(Symbol, getCurrentSection().first);
113 MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
115 // We have to create a new fragment if this is an atom defining symbol,
116 // fragments cannot span atoms.
117 if (getAssembler().isSymbolLinkerVisible(SD.getSymbol()))
118 insert(new MCDataFragment());
120 // FIXME: This is wasteful, we don't necessarily need to create a data
121 // fragment. Instead, we should mark the symbol as pointing into the data
122 // fragment if it exists, otherwise we should just queue the label and set its
123 // fragment pointer when we emit the next fragment.
124 MCDataFragment *F = getOrCreateDataFragment();
125 assert(!SD.getFragment() && "Unexpected fragment on symbol data!");
127 SD.setOffset(F->getContents().size());
131 void MCPureStreamer::EmitDebugLabel(MCSymbol *Symbol) {
135 void MCPureStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
136 uint64_t Size, unsigned ByteAlignment) {
137 report_fatal_error("not yet implemented in pure streamer");
140 void MCPureStreamer::EmitBytes(StringRef Data) {
141 // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
143 getOrCreateDataFragment()->getContents().append(Data.begin(), Data.end());
146 void MCPureStreamer::EmitValueToAlignment(unsigned ByteAlignment,
147 int64_t Value, unsigned ValueSize,
148 unsigned MaxBytesToEmit) {
149 // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
151 if (MaxBytesToEmit == 0)
152 MaxBytesToEmit = ByteAlignment;
153 insert(new MCAlignFragment(ByteAlignment, Value, ValueSize, MaxBytesToEmit));
155 // Update the maximum alignment on the current section if necessary.
156 if (ByteAlignment > getCurrentSectionData()->getAlignment())
157 getCurrentSectionData()->setAlignment(ByteAlignment);
160 void MCPureStreamer::EmitCodeAlignment(unsigned ByteAlignment,
161 unsigned MaxBytesToEmit) {
162 // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
164 if (MaxBytesToEmit == 0)
165 MaxBytesToEmit = ByteAlignment;
166 MCAlignFragment *F = new MCAlignFragment(ByteAlignment, 0, 1, MaxBytesToEmit);
168 F->setEmitNops(true);
170 // Update the maximum alignment on the current section if necessary.
171 if (ByteAlignment > getCurrentSectionData()->getAlignment())
172 getCurrentSectionData()->setAlignment(ByteAlignment);
175 bool MCPureStreamer::EmitValueToOffset(const MCExpr *Offset,
176 unsigned char Value) {
177 insert(new MCOrgFragment(*Offset, Value));
181 void MCPureStreamer::EmitInstToFragment(const MCInst &Inst) {
182 MCRelaxableFragment *IF = new MCRelaxableFragment(Inst);
185 // Add the fixups and data.
187 // FIXME: Revisit this design decision when relaxation is done, we may be
188 // able to get away with not storing any extra data in the MCInst.
189 SmallVector<MCFixup, 4> Fixups;
190 SmallString<256> Code;
191 raw_svector_ostream VecOS(Code);
192 getAssembler().getEmitter().EncodeInstruction(Inst, VecOS, Fixups);
195 IF->getContents() = Code;
196 IF->getFixups() = Fixups;
199 void MCPureStreamer::EmitInstToData(const MCInst &Inst) {
200 MCDataFragment *DF = getOrCreateDataFragment();
202 SmallVector<MCFixup, 4> Fixups;
203 SmallString<256> Code;
204 raw_svector_ostream VecOS(Code);
205 getAssembler().getEmitter().EncodeInstruction(Inst, VecOS, Fixups);
208 // Add the fixups and data.
209 for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
210 Fixups[i].setOffset(Fixups[i].getOffset() + DF->getContents().size());
211 DF->getFixups().push_back(Fixups[i]);
213 DF->getContents().append(Code.begin(), Code.end());
216 void MCPureStreamer::FinishImpl() {
217 // FIXME: Handle DWARF tables?
219 this->MCObjectStreamer::FinishImpl();
222 MCStreamer *llvm::createPureStreamer(MCContext &Context, MCAsmBackend &MAB,
223 raw_ostream &OS, MCCodeEmitter *CE) {
224 return new MCPureStreamer(Context, MAB, OS, CE);