1 //===- lib/MC/MCAsmStreamer.cpp - Text Assembly 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/MCAsmInfo.h"
12 #include "llvm/MC/MCCodeEmitter.h"
13 #include "llvm/MC/MCContext.h"
14 #include "llvm/MC/MCExpr.h"
15 #include "llvm/MC/MCInst.h"
16 #include "llvm/MC/MCInstPrinter.h"
17 #include "llvm/MC/MCSectionMachO.h"
18 #include "llvm/MC/MCSymbol.h"
19 #include "llvm/ADT/OwningPtr.h"
20 #include "llvm/ADT/SmallString.h"
21 #include "llvm/ADT/Twine.h"
22 #include "llvm/Support/ErrorHandling.h"
23 #include "llvm/Support/MathExtras.h"
24 #include "llvm/Support/Format.h"
25 #include "llvm/Support/FormattedStream.h"
30 class MCAsmStreamer : public MCStreamer {
31 formatted_raw_ostream &OS;
33 OwningPtr<MCInstPrinter> InstPrinter;
34 MCCodeEmitter *Emitter;
36 SmallString<128> CommentToEmit;
37 raw_svector_ostream CommentStream;
39 unsigned IsLittleEndian : 1;
40 unsigned IsVerboseAsm : 1;
41 unsigned ShowInst : 1;
44 MCAsmStreamer(MCContext &Context, formatted_raw_ostream &os,
45 bool isLittleEndian, bool isVerboseAsm, MCInstPrinter *printer,
46 MCCodeEmitter *emitter, bool showInst)
47 : MCStreamer(Context), OS(os), MAI(Context.getAsmInfo()),
48 InstPrinter(printer), Emitter(emitter), CommentStream(CommentToEmit),
49 IsLittleEndian(isLittleEndian), IsVerboseAsm(isVerboseAsm),
51 if (InstPrinter && IsVerboseAsm)
52 InstPrinter->setCommentStream(CommentStream);
56 bool isLittleEndian() const { return IsLittleEndian; }
58 inline void EmitEOL() {
59 // If we don't have any comments, just emit a \n.
66 void EmitCommentsAndEOL();
68 /// isVerboseAsm - Return true if this streamer supports verbose assembly at
70 virtual bool isVerboseAsm() const { return IsVerboseAsm; }
72 /// AddComment - Add a comment that can be emitted to the generated .s
73 /// file if applicable as a QoI issue to make the output of the compiler
74 /// more readable. This only affects the MCAsmStreamer, and only when
75 /// verbose assembly output is enabled.
76 virtual void AddComment(const Twine &T);
78 /// AddEncodingComment - Add a comment showing the encoding of an instruction.
79 virtual void AddEncodingComment(const MCInst &Inst);
81 /// GetCommentOS - Return a raw_ostream that comments can be written to.
82 /// Unlike AddComment, you are required to terminate comments with \n if you
84 virtual raw_ostream &GetCommentOS() {
86 return nulls(); // Discard comments unless in verbose asm mode.
90 /// AddBlankLine - Emit a blank line to a .s file to pretty it up.
91 virtual void AddBlankLine() {
95 /// @name MCStreamer Interface
98 virtual void SwitchSection(const MCSection *Section);
100 virtual void EmitLabel(MCSymbol *Symbol);
102 virtual void EmitAssemblerFlag(MCAssemblerFlag Flag);
104 virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value);
106 virtual void EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute);
108 virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue);
110 virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value);
111 virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
112 unsigned ByteAlignment);
114 /// EmitLocalCommonSymbol - Emit a local common (.lcomm) symbol.
116 /// @param Symbol - The common symbol to emit.
117 /// @param Size - The size of the common symbol.
118 virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size);
120 virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
121 unsigned Size = 0, unsigned ByteAlignment = 0);
123 virtual void EmitBytes(StringRef Data, unsigned AddrSpace);
125 virtual void EmitValue(const MCExpr *Value, unsigned Size,unsigned AddrSpace);
126 virtual void EmitIntValue(uint64_t Value, unsigned Size, unsigned AddrSpace);
127 virtual void EmitGPRel32Value(const MCExpr *Value);
130 virtual void EmitFill(uint64_t NumBytes, uint8_t FillValue,
133 virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
134 unsigned ValueSize = 1,
135 unsigned MaxBytesToEmit = 0);
137 virtual void EmitCodeAlignment(unsigned ByteAlignment,
138 unsigned MaxBytesToEmit = 0);
140 virtual void EmitValueToOffset(const MCExpr *Offset,
141 unsigned char Value = 0);
143 virtual void EmitFileDirective(StringRef Filename);
144 virtual void EmitDwarfFileDirective(unsigned FileNo, StringRef Filename);
146 virtual void EmitInstruction(const MCInst &Inst);
148 virtual void Finish();
153 } // end anonymous namespace.
155 /// AddComment - Add a comment that can be emitted to the generated .s
156 /// file if applicable as a QoI issue to make the output of the compiler
157 /// more readable. This only affects the MCAsmStreamer, and only when
158 /// verbose assembly output is enabled.
159 void MCAsmStreamer::AddComment(const Twine &T) {
160 if (!IsVerboseAsm) return;
162 // Make sure that CommentStream is flushed.
163 CommentStream.flush();
165 T.toVector(CommentToEmit);
166 // Each comment goes on its own line.
167 CommentToEmit.push_back('\n');
169 // Tell the comment stream that the vector changed underneath it.
170 CommentStream.resync();
173 void MCAsmStreamer::EmitCommentsAndEOL() {
174 if (CommentToEmit.empty() && CommentStream.GetNumBytesInBuffer() == 0) {
179 CommentStream.flush();
180 StringRef Comments = CommentToEmit.str();
182 assert(Comments.back() == '\n' &&
183 "Comment array not newline terminated");
185 // Emit a line of comments.
186 OS.PadToColumn(MAI.getCommentColumn());
187 size_t Position = Comments.find('\n');
188 OS << MAI.getCommentString() << ' ' << Comments.substr(0, Position) << '\n';
190 Comments = Comments.substr(Position+1);
191 } while (!Comments.empty());
193 CommentToEmit.clear();
194 // Tell the comment stream that the vector changed underneath it.
195 CommentStream.resync();
199 static inline int64_t truncateToSize(int64_t Value, unsigned Bytes) {
200 assert(Bytes && "Invalid size!");
201 return Value & ((uint64_t) (int64_t) -1 >> (64 - Bytes * 8));
204 void MCAsmStreamer::SwitchSection(const MCSection *Section) {
205 assert(Section && "Cannot switch to a null section!");
206 if (Section != CurSection) {
207 CurSection = Section;
208 Section->PrintSwitchToSection(MAI, OS);
212 void MCAsmStreamer::EmitLabel(MCSymbol *Symbol) {
213 assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
214 assert(CurSection && "Cannot emit before setting section!");
216 OS << *Symbol << ":";
218 Symbol->setSection(*CurSection);
221 void MCAsmStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
223 default: assert(0 && "Invalid flag!");
224 case MCAF_SubsectionsViaSymbols: OS << ".subsections_via_symbols"; break;
229 void MCAsmStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
230 // Only absolute symbols can be redefined.
231 assert((Symbol->isUndefined() || Symbol->isAbsolute()) &&
232 "Cannot define a symbol twice!");
234 OS << *Symbol << " = " << *Value;
237 // FIXME: Lift context changes into super class.
238 // FIXME: Set associated section.
239 Symbol->setValue(Value);
242 void MCAsmStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
243 MCSymbolAttr Attribute) {
245 case MCSA_Invalid: assert(0 && "Invalid symbol attribute");
246 case MCSA_ELF_TypeFunction: /// .type _foo, STT_FUNC # aka @function
247 case MCSA_ELF_TypeIndFunction: /// .type _foo, STT_GNU_IFUNC
248 case MCSA_ELF_TypeObject: /// .type _foo, STT_OBJECT # aka @object
249 case MCSA_ELF_TypeTLS: /// .type _foo, STT_TLS # aka @tls_object
250 case MCSA_ELF_TypeCommon: /// .type _foo, STT_COMMON # aka @common
251 case MCSA_ELF_TypeNoType: /// .type _foo, STT_NOTYPE # aka @notype
252 assert(MAI.hasDotTypeDotSizeDirective() && "Symbol Attr not supported");
253 OS << "\t.type\t" << *Symbol << ','
254 << ((MAI.getCommentString()[0] != '@') ? '@' : '%');
256 default: assert(0 && "Unknown ELF .type");
257 case MCSA_ELF_TypeFunction: OS << "function"; break;
258 case MCSA_ELF_TypeIndFunction: OS << "gnu_indirect_function"; break;
259 case MCSA_ELF_TypeObject: OS << "object"; break;
260 case MCSA_ELF_TypeTLS: OS << "tls_object"; break;
261 case MCSA_ELF_TypeCommon: OS << "common"; break;
262 case MCSA_ELF_TypeNoType: OS << "no_type"; break;
266 case MCSA_Global: // .globl/.global
267 OS << MAI.getGlobalDirective();
269 case MCSA_Hidden: OS << ".hidden "; break;
270 case MCSA_IndirectSymbol: OS << ".indirect_symbol "; break;
271 case MCSA_Internal: OS << ".internal "; break;
272 case MCSA_LazyReference: OS << ".lazy_reference "; break;
273 case MCSA_Local: OS << ".local "; break;
274 case MCSA_NoDeadStrip: OS << ".no_dead_strip "; break;
275 case MCSA_PrivateExtern: OS << ".private_extern "; break;
276 case MCSA_Protected: OS << ".protected "; break;
277 case MCSA_Reference: OS << ".reference "; break;
278 case MCSA_Weak: OS << ".weak "; break;
279 case MCSA_WeakDefinition: OS << ".weak_definition "; break;
281 case MCSA_WeakReference: OS << MAI.getWeakRefDirective(); break;
288 void MCAsmStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
289 OS << ".desc" << ' ' << *Symbol << ',' << DescValue;
293 void MCAsmStreamer::EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
294 assert(MAI.hasDotTypeDotSizeDirective());
295 OS << "\t.size\t" << *Symbol << ", " << *Value << '\n';
298 void MCAsmStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
299 unsigned ByteAlignment) {
300 OS << "\t.comm\t" << *Symbol << ',' << Size;
301 if (ByteAlignment != 0) {
302 if (MAI.getCOMMDirectiveAlignmentIsInBytes())
303 OS << ',' << ByteAlignment;
305 OS << ',' << Log2_32(ByteAlignment);
310 /// EmitLocalCommonSymbol - Emit a local common (.lcomm) symbol.
312 /// @param Symbol - The common symbol to emit.
313 /// @param Size - The size of the common symbol.
314 void MCAsmStreamer::EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size) {
315 assert(MAI.hasLCOMMDirective() && "Doesn't have .lcomm, can't emit it!");
316 OS << "\t.lcomm\t" << *Symbol << ',' << Size;
320 void MCAsmStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
321 unsigned Size, unsigned ByteAlignment) {
322 // Note: a .zerofill directive does not switch sections.
325 // This is a mach-o specific directive.
326 const MCSectionMachO *MOSection = ((const MCSectionMachO*)Section);
327 OS << MOSection->getSegmentName() << "," << MOSection->getSectionName();
329 if (Symbol != NULL) {
330 OS << ',' << *Symbol << ',' << Size;
331 if (ByteAlignment != 0)
332 OS << ',' << Log2_32(ByteAlignment);
337 static inline char toOctal(int X) { return (X&7)+'0'; }
339 static void PrintQuotedString(StringRef Data, raw_ostream &OS) {
342 for (unsigned i = 0, e = Data.size(); i != e; ++i) {
343 unsigned char C = Data[i];
344 if (C == '"' || C == '\\') {
345 OS << '\\' << (char)C;
349 if (isprint((unsigned char)C)) {
355 case '\b': OS << "\\b"; break;
356 case '\f': OS << "\\f"; break;
357 case '\n': OS << "\\n"; break;
358 case '\r': OS << "\\r"; break;
359 case '\t': OS << "\\t"; break;
362 OS << toOctal(C >> 6);
363 OS << toOctal(C >> 3);
364 OS << toOctal(C >> 0);
373 void MCAsmStreamer::EmitBytes(StringRef Data, unsigned AddrSpace) {
374 assert(CurSection && "Cannot emit contents before setting section!");
375 if (Data.empty()) return;
377 if (Data.size() == 1) {
378 OS << MAI.getData8bitsDirective(AddrSpace);
379 OS << (unsigned)(unsigned char)Data[0];
384 // If the data ends with 0 and the target supports .asciz, use it, otherwise
386 if (MAI.getAscizDirective() && Data.back() == 0) {
387 OS << MAI.getAscizDirective();
388 Data = Data.substr(0, Data.size()-1);
390 OS << MAI.getAsciiDirective();
394 PrintQuotedString(Data, OS);
398 /// EmitIntValue - Special case of EmitValue that avoids the client having
399 /// to pass in a MCExpr for constant integers.
400 void MCAsmStreamer::EmitIntValue(uint64_t Value, unsigned Size,
401 unsigned AddrSpace) {
402 assert(CurSection && "Cannot emit contents before setting section!");
403 const char *Directive = 0;
406 case 1: Directive = MAI.getData8bitsDirective(AddrSpace); break;
407 case 2: Directive = MAI.getData16bitsDirective(AddrSpace); break;
408 case 4: Directive = MAI.getData32bitsDirective(AddrSpace); break;
410 Directive = MAI.getData64bitsDirective(AddrSpace);
411 // If the target doesn't support 64-bit data, emit as two 32-bit halves.
412 if (Directive) break;
413 if (isLittleEndian()) {
414 EmitIntValue((uint32_t)(Value >> 0 ), 4, AddrSpace);
415 EmitIntValue((uint32_t)(Value >> 32), 4, AddrSpace);
417 EmitIntValue((uint32_t)(Value >> 32), 4, AddrSpace);
418 EmitIntValue((uint32_t)(Value >> 0 ), 4, AddrSpace);
423 assert(Directive && "Invalid size for machine code value!");
424 OS << Directive << truncateToSize(Value, Size);
428 void MCAsmStreamer::EmitValue(const MCExpr *Value, unsigned Size,
429 unsigned AddrSpace) {
430 assert(CurSection && "Cannot emit contents before setting section!");
431 const char *Directive = 0;
434 case 1: Directive = MAI.getData8bitsDirective(AddrSpace); break;
435 case 2: Directive = MAI.getData16bitsDirective(AddrSpace); break;
436 case 4: Directive = MAI.getData32bitsDirective(AddrSpace); break;
437 case 8: Directive = MAI.getData64bitsDirective(AddrSpace); break;
440 assert(Directive && "Invalid size for machine code value!");
441 OS << Directive << *Value;
445 void MCAsmStreamer::EmitGPRel32Value(const MCExpr *Value) {
446 assert(MAI.getGPRel32Directive() != 0);
447 OS << MAI.getGPRel32Directive() << *Value;
452 /// EmitFill - Emit NumBytes bytes worth of the value specified by
453 /// FillValue. This implements directives such as '.space'.
454 void MCAsmStreamer::EmitFill(uint64_t NumBytes, uint8_t FillValue,
455 unsigned AddrSpace) {
456 if (NumBytes == 0) return;
459 if (const char *ZeroDirective = MAI.getZeroDirective()) {
460 OS << ZeroDirective << NumBytes;
462 OS << ',' << (int)FillValue;
467 // Emit a byte at a time.
468 MCStreamer::EmitFill(NumBytes, FillValue, AddrSpace);
471 void MCAsmStreamer::EmitValueToAlignment(unsigned ByteAlignment, int64_t Value,
473 unsigned MaxBytesToEmit) {
474 // Some assemblers don't support non-power of two alignments, so we always
475 // emit alignments as a power of two if possible.
476 if (isPowerOf2_32(ByteAlignment)) {
478 default: llvm_unreachable("Invalid size for machine code value!");
479 case 1: OS << MAI.getAlignDirective(); break;
480 // FIXME: use MAI for this!
481 case 2: OS << ".p2alignw "; break;
482 case 4: OS << ".p2alignl "; break;
483 case 8: llvm_unreachable("Unsupported alignment size!");
486 if (MAI.getAlignmentIsInBytes())
489 OS << Log2_32(ByteAlignment);
491 if (Value || MaxBytesToEmit) {
493 OS.write_hex(truncateToSize(Value, ValueSize));
496 OS << ", " << MaxBytesToEmit;
502 // Non-power of two alignment. This is not widely supported by assemblers.
503 // FIXME: Parameterize this based on MAI.
505 default: llvm_unreachable("Invalid size for machine code value!");
506 case 1: OS << ".balign"; break;
507 case 2: OS << ".balignw"; break;
508 case 4: OS << ".balignl"; break;
509 case 8: llvm_unreachable("Unsupported alignment size!");
512 OS << ' ' << ByteAlignment;
513 OS << ", " << truncateToSize(Value, ValueSize);
515 OS << ", " << MaxBytesToEmit;
519 void MCAsmStreamer::EmitCodeAlignment(unsigned ByteAlignment,
520 unsigned MaxBytesToEmit) {
521 // Emit with a text fill value.
522 EmitValueToAlignment(ByteAlignment, MAI.getTextAlignFillValue(),
526 void MCAsmStreamer::EmitValueToOffset(const MCExpr *Offset,
527 unsigned char Value) {
528 // FIXME: Verify that Offset is associated with the current section.
529 OS << ".org " << *Offset << ", " << (unsigned) Value;
534 void MCAsmStreamer::EmitFileDirective(StringRef Filename) {
535 assert(MAI.hasSingleParameterDotFile());
537 PrintQuotedString(Filename, OS);
541 void MCAsmStreamer::EmitDwarfFileDirective(unsigned FileNo, StringRef Filename){
542 OS << "\t.file\t" << FileNo << ' ';
543 PrintQuotedString(Filename, OS);
547 void MCAsmStreamer::AddEncodingComment(const MCInst &Inst) {
548 raw_ostream &OS = GetCommentOS();
549 SmallString<256> Code;
550 SmallVector<MCFixup, 4> Fixups;
551 raw_svector_ostream VecOS(Code);
552 Emitter->EncodeInstruction(Inst, VecOS, Fixups);
555 // If we are showing fixups, create symbolic markers in the encoded
556 // representation. We do this by making a per-bit map to the fixup item index,
557 // then trying to display it as nicely as possible.
558 SmallVector<uint8_t, 64> FixupMap;
559 FixupMap.resize(Code.size() * 8);
560 for (unsigned i = 0, e = Code.size() * 8; i != e; ++i)
563 for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
564 MCFixup &F = Fixups[i];
565 const MCFixupKindInfo &Info = Emitter->getFixupKindInfo(F.getKind());
566 for (unsigned j = 0; j != Info.TargetSize; ++j) {
567 unsigned Index = F.getOffset() * 8 + Info.TargetOffset + j;
568 assert(Index < Code.size() * 8 && "Invalid offset in fixup!");
569 FixupMap[Index] = 1 + i;
574 for (unsigned i = 0, e = Code.size(); i != e; ++i) {
578 // See if all bits are the same map entry.
579 uint8_t MapEntry = FixupMap[i * 8 + 0];
580 for (unsigned j = 1; j != 8; ++j) {
581 if (FixupMap[i * 8 + j] == MapEntry)
584 MapEntry = uint8_t(~0U);
588 if (MapEntry != uint8_t(~0U)) {
590 OS << format("0x%02x", uint8_t(Code[i]));
592 assert(Code[i] == 0 && "Encoder wrote into fixed up bit!");
593 OS << char('A' + MapEntry - 1);
596 // Otherwise, write out in binary.
598 for (unsigned j = 8; j--;) {
599 unsigned Bit = (Code[i] >> j) & 1;
600 if (uint8_t MapEntry = FixupMap[i * 8 + j]) {
601 assert(Bit == 0 && "Encoder wrote into fixed up bit!");
602 OS << char('A' + MapEntry - 1);
610 for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
611 MCFixup &F = Fixups[i];
612 const MCFixupKindInfo &Info = Emitter->getFixupKindInfo(F.getKind());
613 OS << " fixup " << char('A' + i) << " - " << "offset: " << F.getOffset()
614 << ", value: " << *F.getValue() << ", kind: " << Info.Name << "\n";
618 void MCAsmStreamer::EmitInstruction(const MCInst &Inst) {
619 assert(CurSection && "Cannot emit contents before setting section!");
621 // Show the encoding in a comment if we have a code emitter.
623 AddEncodingComment(Inst);
625 // Show the MCInst if enabled.
627 Inst.dump_pretty(GetCommentOS(), &MAI, InstPrinter.get(), "\n ");
629 // If we have an AsmPrinter, use that to print, otherwise print the MCInst.
631 InstPrinter->printInst(&Inst);
633 Inst.print(OS, &MAI);
637 void MCAsmStreamer::Finish() {
641 MCStreamer *llvm::createAsmStreamer(MCContext &Context,
642 formatted_raw_ostream &OS,
644 bool isVerboseAsm, MCInstPrinter *IP,
645 MCCodeEmitter *CE, bool ShowInst) {
646 return new MCAsmStreamer(Context, OS, isLittleEndian, isVerboseAsm,