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/MCObjectStreamer.h"
16 // FIXME: Remove this.
17 #include "llvm/MC/MCSectionMachO.h"
18 #include "llvm/MC/MCSymbol.h"
19 #include "llvm/Support/ErrorHandling.h"
25 class MCPureStreamer : public MCObjectStreamer {
27 virtual void EmitInstToFragment(const MCInst &Inst);
28 virtual void EmitInstToData(const MCInst &Inst);
31 MCPureStreamer(MCContext &Context, MCAsmBackend &TAB,
32 raw_ostream &OS, MCCodeEmitter *Emitter)
33 : MCObjectStreamer(Context, TAB, OS, Emitter) {}
35 /// @name MCStreamer Interface
38 virtual void InitSections();
39 virtual void EmitLabel(MCSymbol *Symbol);
40 virtual void EmitDebugLabel(MCSymbol *Symbol);
41 virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
42 uint64_t Size = 0, unsigned ByteAlignment = 0);
43 virtual void EmitBytes(StringRef Data, unsigned AddrSpace);
44 virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
45 unsigned ValueSize = 1,
46 unsigned MaxBytesToEmit = 0);
47 virtual void EmitCodeAlignment(unsigned ByteAlignment,
48 unsigned MaxBytesToEmit = 0);
49 virtual bool EmitValueToOffset(const MCExpr *Offset,
50 unsigned char Value = 0);
51 virtual void FinishImpl();
54 virtual void EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute) {
55 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 bool EmitDwarfFileDirective(unsigned FileNo, StringRef Directory,
98 report_fatal_error("unsupported directive in pure streamer");
104 } // end anonymous namespace.
106 void MCPureStreamer::InitSections() {
108 SwitchSection(getContext().getMachOSection("__TEXT", "__text",
109 MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
110 0, SectionKind::getText()));
114 void MCPureStreamer::EmitLabel(MCSymbol *Symbol) {
115 assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
116 assert(!Symbol->isVariable() && "Cannot emit a variable symbol!");
117 assert(getCurrentSection() && "Cannot emit before setting section!");
119 Symbol->setSection(*getCurrentSection());
121 MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
123 // We have to create a new fragment if this is an atom defining symbol,
124 // fragments cannot span atoms.
125 if (getAssembler().isSymbolLinkerVisible(SD.getSymbol()))
126 new MCDataFragment(getCurrentSectionData());
128 // FIXME: This is wasteful, we don't necessarily need to create a data
129 // fragment. Instead, we should mark the symbol as pointing into the data
130 // fragment if it exists, otherwise we should just queue the label and set its
131 // fragment pointer when we emit the next fragment.
132 MCDataFragment *F = getOrCreateDataFragment();
133 assert(!SD.getFragment() && "Unexpected fragment on symbol data!");
135 SD.setOffset(F->getContents().size());
139 void MCPureStreamer::EmitDebugLabel(MCSymbol *Symbol) {
143 void MCPureStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
144 uint64_t Size, unsigned ByteAlignment) {
145 report_fatal_error("not yet implemented in pure streamer");
148 void MCPureStreamer::EmitBytes(StringRef Data, unsigned AddrSpace) {
149 // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
151 getOrCreateDataFragment()->getContents().append(Data.begin(), Data.end());
154 void MCPureStreamer::EmitValueToAlignment(unsigned ByteAlignment,
155 int64_t Value, unsigned ValueSize,
156 unsigned MaxBytesToEmit) {
157 // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
159 if (MaxBytesToEmit == 0)
160 MaxBytesToEmit = ByteAlignment;
161 new MCAlignFragment(ByteAlignment, Value, ValueSize, MaxBytesToEmit,
162 getCurrentSectionData());
164 // Update the maximum alignment on the current section if necessary.
165 if (ByteAlignment > getCurrentSectionData()->getAlignment())
166 getCurrentSectionData()->setAlignment(ByteAlignment);
169 void MCPureStreamer::EmitCodeAlignment(unsigned ByteAlignment,
170 unsigned MaxBytesToEmit) {
171 // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
173 if (MaxBytesToEmit == 0)
174 MaxBytesToEmit = ByteAlignment;
175 MCAlignFragment *F = new MCAlignFragment(ByteAlignment, 0, 1, MaxBytesToEmit,
176 getCurrentSectionData());
177 F->setEmitNops(true);
179 // Update the maximum alignment on the current section if necessary.
180 if (ByteAlignment > getCurrentSectionData()->getAlignment())
181 getCurrentSectionData()->setAlignment(ByteAlignment);
184 bool MCPureStreamer::EmitValueToOffset(const MCExpr *Offset,
185 unsigned char Value) {
186 new MCOrgFragment(*Offset, Value, getCurrentSectionData());
190 void MCPureStreamer::EmitInstToFragment(const MCInst &Inst) {
191 MCInstFragment *IF = new MCInstFragment(Inst, getCurrentSectionData());
193 // Add the fixups and data.
195 // FIXME: Revisit this design decision when relaxation is done, we may be
196 // able to get away with not storing any extra data in the MCInst.
197 SmallVector<MCFixup, 4> Fixups;
198 SmallString<256> Code;
199 raw_svector_ostream VecOS(Code);
200 getAssembler().getEmitter().EncodeInstruction(Inst, VecOS, Fixups);
203 IF->getContents() = Code;
204 IF->getFixups() = Fixups;
207 void MCPureStreamer::EmitInstToData(const MCInst &Inst) {
208 MCDataFragment *DF = getOrCreateDataFragment();
210 SmallVector<MCFixup, 4> Fixups;
211 SmallString<256> Code;
212 raw_svector_ostream VecOS(Code);
213 getAssembler().getEmitter().EncodeInstruction(Inst, VecOS, Fixups);
216 // Add the fixups and data.
217 for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
218 Fixups[i].setOffset(Fixups[i].getOffset() + DF->getContents().size());
219 DF->getFixups().push_back(Fixups[i]);
221 DF->getContents().append(Code.begin(), Code.end());
224 void MCPureStreamer::FinishImpl() {
225 // FIXME: Handle DWARF tables?
227 this->MCObjectStreamer::FinishImpl();
230 MCStreamer *llvm::createPureStreamer(MCContext &Context, MCAsmBackend &MAB,
231 raw_ostream &OS, MCCodeEmitter *CE) {
232 return new MCPureStreamer(Context, MAB, OS, CE);