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, TargetAsmBackend &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 EmitAssignment(MCSymbol *Symbol, const MCExpr *Value);
41 virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
42 unsigned 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 void EmitValueToOffset(const MCExpr *Offset,
50 unsigned char Value = 0);
51 virtual void Finish();
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 EmitCOFFSecRel32(MCSymbol const *Symbol) {
87 report_fatal_error("unsupported directive in pure streamer");
89 virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
90 report_fatal_error("unsupported directive in pure streamer");
92 virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size) {
93 report_fatal_error("unsupported directive in pure streamer");
95 virtual void EmitFileDirective(StringRef Filename) {
96 report_fatal_error("unsupported directive in pure streamer");
98 virtual bool EmitDwarfFileDirective(unsigned FileNo, StringRef Filename) {
99 report_fatal_error("unsupported directive in pure streamer");
106 } // end anonymous namespace.
108 void MCPureStreamer::InitSections() {
110 SwitchSection(getContext().getMachOSection("__TEXT", "__text",
111 MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
112 0, SectionKind::getText()));
116 void MCPureStreamer::EmitLabel(MCSymbol *Symbol) {
117 assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
118 assert(!Symbol->isVariable() && "Cannot emit a variable symbol!");
119 assert(getCurrentSection() && "Cannot emit before setting section!");
121 Symbol->setSection(*getCurrentSection());
123 MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
125 // We have to create a new fragment if this is an atom defining symbol,
126 // fragments cannot span atoms.
127 if (getAssembler().isSymbolLinkerVisible(SD.getSymbol()))
128 new MCDataFragment(getCurrentSectionData());
130 // FIXME: This is wasteful, we don't necessarily need to create a data
131 // fragment. Instead, we should mark the symbol as pointing into the data
132 // fragment if it exists, otherwise we should just queue the label and set its
133 // fragment pointer when we emit the next fragment.
134 MCDataFragment *F = getOrCreateDataFragment();
135 assert(!SD.getFragment() && "Unexpected fragment on symbol data!");
137 SD.setOffset(F->getContents().size());
140 void MCPureStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
141 // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
143 // FIXME: Lift context changes into super class.
144 getAssembler().getOrCreateSymbolData(*Symbol);
145 Symbol->setVariableValue(AddValueSymbols(Value));
148 void MCPureStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
149 unsigned Size, unsigned ByteAlignment) {
150 report_fatal_error("not yet implemented in pure streamer");
153 void MCPureStreamer::EmitBytes(StringRef Data, unsigned AddrSpace) {
154 // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
156 getOrCreateDataFragment()->getContents().append(Data.begin(), Data.end());
159 void MCPureStreamer::EmitValueToAlignment(unsigned ByteAlignment,
160 int64_t Value, unsigned ValueSize,
161 unsigned MaxBytesToEmit) {
162 // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
164 if (MaxBytesToEmit == 0)
165 MaxBytesToEmit = ByteAlignment;
166 new MCAlignFragment(ByteAlignment, Value, ValueSize, MaxBytesToEmit,
167 getCurrentSectionData());
169 // Update the maximum alignment on the current section if necessary.
170 if (ByteAlignment > getCurrentSectionData()->getAlignment())
171 getCurrentSectionData()->setAlignment(ByteAlignment);
174 void MCPureStreamer::EmitCodeAlignment(unsigned ByteAlignment,
175 unsigned MaxBytesToEmit) {
176 // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
178 if (MaxBytesToEmit == 0)
179 MaxBytesToEmit = ByteAlignment;
180 MCAlignFragment *F = new MCAlignFragment(ByteAlignment, 0, 1, MaxBytesToEmit,
181 getCurrentSectionData());
182 F->setEmitNops(true);
184 // Update the maximum alignment on the current section if necessary.
185 if (ByteAlignment > getCurrentSectionData()->getAlignment())
186 getCurrentSectionData()->setAlignment(ByteAlignment);
189 void MCPureStreamer::EmitValueToOffset(const MCExpr *Offset,
190 unsigned char Value) {
191 new MCOrgFragment(*Offset, Value, getCurrentSectionData());
194 void MCPureStreamer::EmitInstToFragment(const MCInst &Inst) {
195 MCInstFragment *IF = new MCInstFragment(Inst, getCurrentSectionData());
197 // Add the fixups and data.
199 // FIXME: Revisit this design decision when relaxation is done, we may be
200 // able to get away with not storing any extra data in the MCInst.
201 SmallVector<MCFixup, 4> Fixups;
202 SmallString<256> Code;
203 raw_svector_ostream VecOS(Code);
204 getAssembler().getEmitter().EncodeInstruction(Inst, VecOS, Fixups);
207 IF->getCode() = Code;
208 IF->getFixups() = Fixups;
211 void MCPureStreamer::EmitInstToData(const MCInst &Inst) {
212 MCDataFragment *DF = getOrCreateDataFragment();
214 SmallVector<MCFixup, 4> Fixups;
215 SmallString<256> Code;
216 raw_svector_ostream VecOS(Code);
217 getAssembler().getEmitter().EncodeInstruction(Inst, VecOS, Fixups);
220 // Add the fixups and data.
221 for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
222 Fixups[i].setOffset(Fixups[i].getOffset() + DF->getContents().size());
223 DF->addFixup(Fixups[i]);
225 DF->getContents().append(Code.begin(), Code.end());
228 void MCPureStreamer::Finish() {
229 // FIXME: Handle DWARF tables?
231 this->MCObjectStreamer::Finish();
234 MCStreamer *llvm::createPureStreamer(MCContext &Context, TargetAsmBackend &TAB,
235 raw_ostream &OS, MCCodeEmitter *CE) {
236 return new MCPureStreamer(Context, TAB, OS, CE);