1 //===- lib/MC/MCStreamer.cpp - Streaming Machine Code 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/MCAsmInfo.h"
11 #include "llvm/MC/MCContext.h"
12 #include "llvm/MC/MCStreamer.h"
13 #include "llvm/MC/MCExpr.h"
14 #include "llvm/MC/MCObjectWriter.h"
15 #include "llvm/Support/ErrorHandling.h"
16 #include "llvm/Support/raw_ostream.h"
17 #include "llvm/ADT/SmallString.h"
18 #include "llvm/ADT/Twine.h"
22 MCStreamer::MCStreamer(MCContext &Ctx) : Context(Ctx), CurSection(0),
26 MCStreamer::~MCStreamer() {
29 raw_ostream &MCStreamer::GetCommentOS() {
30 // By default, discard comments.
34 void MCStreamer::EmitDwarfSetLineAddr(int64_t LineDelta,
35 const MCSymbol *Label, int PointerSize) {
36 // emit the sequence to set the address
37 EmitIntValue(dwarf::DW_LNS_extended_op, 1);
38 EmitULEB128IntValue(PointerSize + 1);
39 EmitIntValue(dwarf::DW_LNE_set_address, 1);
40 EmitSymbolValue(Label, PointerSize);
42 // emit the sequence for the LineDelta (from 1) and a zero address delta.
43 MCDwarfLineAddr::Emit(this, LineDelta, 0);
46 /// EmitIntValue - Special case of EmitValue that avoids the client having to
47 /// pass in a MCExpr for constant integers.
48 void MCStreamer::EmitIntValue(uint64_t Value, unsigned Size,
50 assert(Size <= 8 && "Invalid size");
51 unsigned Bits = 8 * Size;
53 assert((isUIntN(Bits, Value) || isIntN(Bits, Value)) && "Invalid size");
55 // FIXME: Endianness assumption.
56 for (unsigned i = 0; i != Size; ++i)
57 buf[i] = uint8_t(Value >> (i * 8));
58 EmitBytes(StringRef(buf, Size), AddrSpace);
61 /// EmitULEB128Value - Special case of EmitULEB128Value that avoids the
62 /// client having to pass in a MCExpr for constant integers.
63 void MCStreamer::EmitULEB128IntValue(uint64_t Value, unsigned AddrSpace) {
65 raw_svector_ostream OSE(Tmp);
66 MCObjectWriter::EncodeULEB128(Value, OSE);
67 EmitBytes(OSE.str(), AddrSpace);
70 /// EmitSLEB128Value - Special case of EmitSLEB128Value that avoids the
71 /// client having to pass in a MCExpr for constant integers.
72 void MCStreamer::EmitSLEB128IntValue(int64_t Value, unsigned AddrSpace) {
74 raw_svector_ostream OSE(Tmp);
75 MCObjectWriter::EncodeSLEB128(Value, OSE);
76 EmitBytes(OSE.str(), AddrSpace);
79 void MCStreamer::EmitAbsValue(const MCExpr *Value, unsigned Size,
81 if (!getContext().getAsmInfo().needsSetToChangeDiffSize()) {
82 EmitValue(Value, Size, AddrSpace);
85 MCSymbol *ABS = getContext().CreateTempSymbol();
86 EmitAssignment(ABS, Value);
87 EmitSymbolValue(ABS, Size, AddrSpace);
91 void MCStreamer::EmitValue(const MCExpr *Value, unsigned Size,
93 EmitValueImpl(Value, Size, false, AddrSpace);
96 void MCStreamer::EmitPCRelValue(const MCExpr *Value, unsigned Size,
98 EmitValueImpl(Value, Size, true, AddrSpace);
101 void MCStreamer::EmitSymbolValue(const MCSymbol *Sym, unsigned Size,
102 bool isPCRel, unsigned AddrSpace) {
103 EmitValueImpl(MCSymbolRefExpr::Create(Sym, getContext()), Size, isPCRel,
107 void MCStreamer::EmitSymbolValue(const MCSymbol *Sym, unsigned Size,
108 unsigned AddrSpace) {
109 EmitSymbolValue(Sym, Size, false, AddrSpace);
112 void MCStreamer::EmitPCRelSymbolValue(const MCSymbol *Sym, unsigned Size,
113 unsigned AddrSpace) {
114 EmitSymbolValue(Sym, Size, true, AddrSpace);
117 void MCStreamer::EmitGPRel32Value(const MCExpr *Value) {
118 report_fatal_error("unsupported directive in streamer");
121 /// EmitFill - Emit NumBytes bytes worth of the value specified by
122 /// FillValue. This implements directives such as '.space'.
123 void MCStreamer::EmitFill(uint64_t NumBytes, uint8_t FillValue,
124 unsigned AddrSpace) {
125 const MCExpr *E = MCConstantExpr::Create(FillValue, getContext());
126 for (uint64_t i = 0, e = NumBytes; i != e; ++i)
127 EmitValue(E, 1, AddrSpace);
130 bool MCStreamer::EmitDwarfFileDirective(unsigned FileNo,
131 StringRef Filename) {
132 return getContext().GetDwarfFile(Filename, FileNo) == 0;
135 void MCStreamer::EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
136 unsigned Column, unsigned Flags,
138 unsigned Discriminator) {
139 getContext().setCurrentDwarfLoc(FileNo, Line, Column, Flags, Isa,
143 MCDwarfFrameInfo *MCStreamer::getCurrentFrameInfo() {
144 if (FrameInfos.empty())
146 return &FrameInfos.back();
149 void MCStreamer::EnsureValidFrame() {
150 MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
151 if (!CurFrame || CurFrame->End)
152 report_fatal_error("No open frame");
155 bool MCStreamer::EmitCFIStartProc() {
156 MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
157 if (CurFrame && !CurFrame->End) {
158 report_fatal_error("Starting a frame before finishing the previous one!");
161 MCDwarfFrameInfo Frame = {0, 0, 0, 0};
162 Frame.Begin = getContext().CreateTempSymbol();
163 EmitLabel(Frame.Begin);
164 FrameInfos.push_back(Frame);
168 bool MCStreamer::EmitCFIEndProc() {
170 MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
171 CurFrame->End = getContext().CreateTempSymbol();
172 EmitLabel(CurFrame->End);
176 bool MCStreamer::EmitCFIDefCfaOffset(int64_t Offset) {
181 bool MCStreamer::EmitCFIDefCfaRegister(int64_t Register) {
186 bool MCStreamer::EmitCFIOffset(int64_t Register, int64_t Offset) {
191 bool MCStreamer::EmitCFIPersonality(const MCSymbol *Sym) {
193 MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
194 CurFrame->Personality = Sym;
198 bool MCStreamer::EmitCFILsda(const MCSymbol *Sym) {
200 MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo();
201 CurFrame->Lsda = Sym;
205 /// EmitRawText - If this file is backed by an assembly streamer, this dumps
206 /// the specified string in the output .s file. This capability is
207 /// indicated by the hasRawTextSupport() predicate.
208 void MCStreamer::EmitRawText(StringRef String) {
209 errs() << "EmitRawText called on an MCStreamer that doesn't support it, "
210 " something must not be fully mc'ized\n";
214 void MCStreamer::EmitRawText(const Twine &T) {
215 SmallString<128> Str;
217 EmitRawText(Str.str());