MCStreamer.cpp revision 5bba08425374ca36fe5fbc7423ce1a09858e4097
1//===- lib/MC/MCStreamer.cpp - Streaming Machine Code Output --------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9 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" 19#include <cstdlib> 20using namespace llvm; 21 22MCStreamer::MCStreamer(MCContext &Ctx) : Context(Ctx), CurSection(0), 23 PrevSection(0) { 24} 25 26MCStreamer::~MCStreamer() { 27} 28 29raw_ostream &MCStreamer::GetCommentOS() { 30 // By default, discard comments. 31 return nulls(); 32} 33 34void 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); 41 42 // emit the sequence for the LineDelta (from 1) and a zero address delta. 43 MCDwarfLineAddr::Emit(this, LineDelta, 0); 44} 45 46/// EmitIntValue - Special case of EmitValue that avoids the client having to 47/// pass in a MCExpr for constant integers. 48void MCStreamer::EmitIntValue(uint64_t Value, unsigned Size, 49 unsigned AddrSpace) { 50 assert(Size <= 8 && "Invalid size"); 51 assert((isUIntN(8 * Size, Value) || isIntN(8 * Size, Value)) && 52 "Invalid size"); 53 char buf[8]; 54 // FIXME: Endianness assumption. 55 for (unsigned i = 0; i != Size; ++i) 56 buf[i] = uint8_t(Value >> (i * 8)); 57 EmitBytes(StringRef(buf, Size), AddrSpace); 58} 59 60/// EmitULEB128Value - Special case of EmitULEB128Value that avoids the 61/// client having to pass in a MCExpr for constant integers. 62void MCStreamer::EmitULEB128IntValue(uint64_t Value, unsigned AddrSpace) { 63 SmallString<32> Tmp; 64 raw_svector_ostream OSE(Tmp); 65 MCObjectWriter::EncodeULEB128(Value, OSE); 66 EmitBytes(OSE.str(), AddrSpace); 67} 68 69/// EmitSLEB128Value - Special case of EmitSLEB128Value that avoids the 70/// client having to pass in a MCExpr for constant integers. 71void MCStreamer::EmitSLEB128IntValue(int64_t Value, unsigned AddrSpace) { 72 SmallString<32> Tmp; 73 raw_svector_ostream OSE(Tmp); 74 MCObjectWriter::EncodeSLEB128(Value, OSE); 75 EmitBytes(OSE.str(), AddrSpace); 76} 77 78void MCStreamer::EmitAbsValue(const MCExpr *Value, unsigned Size, 79 unsigned AddrSpace) { 80 if (getContext().getAsmInfo().hasAggressiveSymbolFolding()) { 81 EmitValue(Value, Size, AddrSpace); 82 return; 83 } 84 MCSymbol *ABS = getContext().CreateTempSymbol(); 85 EmitAssignment(ABS, Value); 86 EmitSymbolValue(ABS, Size, AddrSpace); 87} 88 89 90void MCStreamer::EmitValue(const MCExpr *Value, unsigned Size, 91 unsigned AddrSpace) { 92 EmitValueImpl(Value, Size, false, AddrSpace); 93} 94 95void MCStreamer::EmitPCRelValue(const MCExpr *Value, unsigned Size, 96 unsigned AddrSpace) { 97 EmitValueImpl(Value, Size, true, AddrSpace); 98} 99 100void MCStreamer::EmitSymbolValue(const MCSymbol *Sym, unsigned Size, 101 bool isPCRel, unsigned AddrSpace) { 102 EmitValueImpl(MCSymbolRefExpr::Create(Sym, getContext()), Size, isPCRel, 103 AddrSpace); 104} 105 106void MCStreamer::EmitSymbolValue(const MCSymbol *Sym, unsigned Size, 107 unsigned AddrSpace) { 108 EmitSymbolValue(Sym, Size, false, AddrSpace); 109} 110 111void MCStreamer::EmitPCRelSymbolValue(const MCSymbol *Sym, unsigned Size, 112 unsigned AddrSpace) { 113 EmitSymbolValue(Sym, Size, true, AddrSpace); 114} 115 116void MCStreamer::EmitGPRel32Value(const MCExpr *Value) { 117 report_fatal_error("unsupported directive in streamer"); 118} 119 120/// EmitFill - Emit NumBytes bytes worth of the value specified by 121/// FillValue. This implements directives such as '.space'. 122void MCStreamer::EmitFill(uint64_t NumBytes, uint8_t FillValue, 123 unsigned AddrSpace) { 124 const MCExpr *E = MCConstantExpr::Create(FillValue, getContext()); 125 for (uint64_t i = 0, e = NumBytes; i != e; ++i) 126 EmitValue(E, 1, AddrSpace); 127} 128 129bool MCStreamer::EmitDwarfFileDirective(unsigned FileNo, 130 StringRef Filename) { 131 return getContext().GetDwarfFile(Filename, FileNo) == 0; 132} 133 134void MCStreamer::EmitDwarfLocDirective(unsigned FileNo, unsigned Line, 135 unsigned Column, unsigned Flags, 136 unsigned Isa, 137 unsigned Discriminator) { 138 getContext().setCurrentDwarfLoc(FileNo, Line, Column, Flags, Isa, 139 Discriminator); 140} 141 142MCDwarfFrameInfo *MCStreamer::getCurrentFrameInfo() { 143 if (FrameInfos.empty()) 144 return NULL; 145 return &FrameInfos.back(); 146} 147 148void MCStreamer::EnsureValidFrame() { 149 MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo(); 150 if (!CurFrame || CurFrame->End) 151 report_fatal_error("No open frame"); 152} 153 154bool MCStreamer::EmitCFIStartProc() { 155 MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo(); 156 if (CurFrame && !CurFrame->End) { 157 report_fatal_error("Starting a frame before finishing the previous one!"); 158 return true; 159 } 160 MCDwarfFrameInfo Frame; 161 Frame.Begin = getContext().CreateTempSymbol(); 162 EmitLabel(Frame.Begin); 163 FrameInfos.push_back(Frame); 164 return false; 165} 166 167bool MCStreamer::EmitCFIEndProc() { 168 EnsureValidFrame(); 169 MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo(); 170 CurFrame->End = getContext().CreateTempSymbol(); 171 EmitLabel(CurFrame->End); 172 return false; 173} 174 175bool MCStreamer::EmitCFIDefCfaOffset(int64_t Offset) { 176 EnsureValidFrame(); 177 MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo(); 178 MCSymbol *Label = getContext().CreateTempSymbol(); 179 EmitLabel(Label); 180 MachineLocation Dest(MachineLocation::VirtualFP); 181 MachineLocation Source(MachineLocation::VirtualFP, -Offset); 182 MachineMove Move(Label, Dest, Source); 183 CurFrame->Moves.push_back(Move); 184 return false; 185} 186 187bool MCStreamer::EmitCFIDefCfaRegister(int64_t Register) { 188 EnsureValidFrame(); 189 return false; 190} 191 192bool MCStreamer::EmitCFIOffset(int64_t Register, int64_t Offset) { 193 EnsureValidFrame(); 194 return false; 195} 196 197bool MCStreamer::EmitCFIPersonality(const MCSymbol *Sym, 198 unsigned Encoding) { 199 EnsureValidFrame(); 200 MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo(); 201 CurFrame->Personality = Sym; 202 CurFrame->PersonalityEncoding = Encoding; 203 return false; 204} 205 206bool MCStreamer::EmitCFILsda(const MCSymbol *Sym, unsigned Encoding) { 207 EnsureValidFrame(); 208 MCDwarfFrameInfo *CurFrame = getCurrentFrameInfo(); 209 CurFrame->Lsda = Sym; 210 CurFrame->LsdaEncoding = Encoding; 211 return false; 212} 213 214/// EmitRawText - If this file is backed by an assembly streamer, this dumps 215/// the specified string in the output .s file. This capability is 216/// indicated by the hasRawTextSupport() predicate. 217void MCStreamer::EmitRawText(StringRef String) { 218 errs() << "EmitRawText called on an MCStreamer that doesn't support it, " 219 " something must not be fully mc'ized\n"; 220 abort(); 221} 222 223void MCStreamer::EmitRawText(const Twine &T) { 224 SmallString<128> Str; 225 T.toVector(Str); 226 EmitRawText(Str.str()); 227} 228