X86AsmPrinter.cpp revision 212793 
1//===-- X86AsmPrinter.cpp - Convert X86 LLVM code to AT&T assembly --------===//
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// This file contains a printer that converts from our internal representation
11// of machine-dependent LLVM code to X86 machine code.
12//
13//===----------------------------------------------------------------------===//
14
15#include "X86AsmPrinter.h"
16#include "AsmPrinter/X86ATTInstPrinter.h"
17#include "AsmPrinter/X86IntelInstPrinter.h"
18#include "X86MCInstLower.h"
19#include "X86.h"
20#include "X86COFFMachineModuleInfo.h"
21#include "X86MachineFunctionInfo.h"
22#include "X86TargetMachine.h"
23#include "llvm/CallingConv.h"
24#include "llvm/DerivedTypes.h"
25#include "llvm/Module.h"
26#include "llvm/Type.h"
27#include "llvm/Analysis/DebugInfo.h"
28#include "llvm/Assembly/Writer.h"
29#include "llvm/MC/MCAsmInfo.h"
30#include "llvm/MC/MCContext.h"
31#include "llvm/MC/MCExpr.h"
32#include "llvm/MC/MCSectionMachO.h"
33#include "llvm/MC/MCStreamer.h"
34#include "llvm/MC/MCSymbol.h"
35#include "llvm/CodeGen/MachineJumpTableInfo.h"
36#include "llvm/CodeGen/MachineModuleInfoImpls.h"
37#include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
38#include "llvm/Support/COFF.h"
39#include "llvm/Support/Debug.h"
40#include "llvm/Support/ErrorHandling.h"
41#include "llvm/Target/Mangler.h"
42#include "llvm/Target/TargetOptions.h"
43#include "llvm/Target/TargetRegistry.h"
44#include "llvm/ADT/SmallString.h"
45using namespace llvm;
46
47//===----------------------------------------------------------------------===//
48// Primitive Helper Functions.
49//===----------------------------------------------------------------------===//
50
51void X86AsmPrinter::PrintPICBaseSymbol(raw_ostream &O) const {
52  const TargetLowering *TLI = TM.getTargetLowering();
53  O << *static_cast<const X86TargetLowering*>(TLI)->getPICBaseSymbol(MF,
54                                                                    OutContext);
55}
56
57/// runOnMachineFunction - Emit the function body.
58///
59bool X86AsmPrinter::runOnMachineFunction(MachineFunction &MF) {
60  SetupMachineFunction(MF);
61
62  if (Subtarget->isTargetCOFF()) {
63    bool Intrn = MF.getFunction()->hasInternalLinkage();
64    OutStreamer.BeginCOFFSymbolDef(CurrentFnSym);
65    OutStreamer.EmitCOFFSymbolStorageClass(Intrn ? COFF::IMAGE_SYM_CLASS_STATIC
66                                              : COFF::IMAGE_SYM_CLASS_EXTERNAL);
67    OutStreamer.EmitCOFFSymbolType(COFF::IMAGE_SYM_DTYPE_FUNCTION
68                                               << COFF::SCT_COMPLEX_TYPE_SHIFT);
69    OutStreamer.EndCOFFSymbolDef();
70  }
71
72  // Have common code print out the function header with linkage info etc.
73  EmitFunctionHeader();
74
75  // Emit the rest of the function body.
76  EmitFunctionBody();
77
78  // We didn't modify anything.
79  return false;
80}
81
82/// printSymbolOperand - Print a raw symbol reference operand.  This handles
83/// jump tables, constant pools, global address and external symbols, all of
84/// which print to a label with various suffixes for relocation types etc.
85void X86AsmPrinter::printSymbolOperand(const MachineOperand &MO,
86                                       raw_ostream &O) {
87  switch (MO.getType()) {
88  default: llvm_unreachable("unknown symbol type!");
89  case MachineOperand::MO_JumpTableIndex:
90    O << *GetJTISymbol(MO.getIndex());
91    break;
92  case MachineOperand::MO_ConstantPoolIndex:
93    O << *GetCPISymbol(MO.getIndex());
94    printOffset(MO.getOffset(), O);
95    break;
96  case MachineOperand::MO_GlobalAddress: {
97    const GlobalValue *GV = MO.getGlobal();
98
99    MCSymbol *GVSym;
100    if (MO.getTargetFlags() == X86II::MO_DARWIN_STUB)
101      GVSym = GetSymbolWithGlobalValueBase(GV, "$stub");
102    else if (MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY ||
103             MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY_PIC_BASE ||
104             MO.getTargetFlags() == X86II::MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE)
105      GVSym = GetSymbolWithGlobalValueBase(GV, "$non_lazy_ptr");
106    else
107      GVSym = Mang->getSymbol(GV);
108
109    // Handle dllimport linkage.
110    if (MO.getTargetFlags() == X86II::MO_DLLIMPORT)
111      GVSym = OutContext.GetOrCreateSymbol(Twine("__imp_") + GVSym->getName());
112
113    if (MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY ||
114        MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY_PIC_BASE) {
115      MCSymbol *Sym = GetSymbolWithGlobalValueBase(GV, "$non_lazy_ptr");
116      MachineModuleInfoImpl::StubValueTy &StubSym =
117        MMI->getObjFileInfo<MachineModuleInfoMachO>().getGVStubEntry(Sym);
118      if (StubSym.getPointer() == 0)
119        StubSym = MachineModuleInfoImpl::
120          StubValueTy(Mang->getSymbol(GV), !GV->hasInternalLinkage());
121    } else if (MO.getTargetFlags() == X86II::MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE){
122      MCSymbol *Sym = GetSymbolWithGlobalValueBase(GV, "$non_lazy_ptr");
123      MachineModuleInfoImpl::StubValueTy &StubSym =
124        MMI->getObjFileInfo<MachineModuleInfoMachO>().getHiddenGVStubEntry(Sym);
125      if (StubSym.getPointer() == 0)
126        StubSym = MachineModuleInfoImpl::
127          StubValueTy(Mang->getSymbol(GV), !GV->hasInternalLinkage());
128    } else if (MO.getTargetFlags() == X86II::MO_DARWIN_STUB) {
129      MCSymbol *Sym = GetSymbolWithGlobalValueBase(GV, "$stub");
130      MachineModuleInfoImpl::StubValueTy &StubSym =
131        MMI->getObjFileInfo<MachineModuleInfoMachO>().getFnStubEntry(Sym);
132      if (StubSym.getPointer() == 0)
133        StubSym = MachineModuleInfoImpl::
134          StubValueTy(Mang->getSymbol(GV), !GV->hasInternalLinkage());
135    }
136
137    // If the name begins with a dollar-sign, enclose it in parens.  We do this
138    // to avoid having it look like an integer immediate to the assembler.
139    if (GVSym->getName()[0] != '$')
140      O << *GVSym;
141    else
142      O << '(' << *GVSym << ')';
143    printOffset(MO.getOffset(), O);
144    break;
145  }
146  case MachineOperand::MO_ExternalSymbol: {
147    const MCSymbol *SymToPrint;
148    if (MO.getTargetFlags() == X86II::MO_DARWIN_STUB) {
149      SmallString<128> TempNameStr;
150      TempNameStr += StringRef(MO.getSymbolName());
151      TempNameStr += StringRef("$stub");
152
153      MCSymbol *Sym = GetExternalSymbolSymbol(TempNameStr.str());
154      MachineModuleInfoImpl::StubValueTy &StubSym =
155        MMI->getObjFileInfo<MachineModuleInfoMachO>().getFnStubEntry(Sym);
156      if (StubSym.getPointer() == 0) {
157        TempNameStr.erase(TempNameStr.end()-5, TempNameStr.end());
158        StubSym = MachineModuleInfoImpl::
159          StubValueTy(OutContext.GetOrCreateSymbol(TempNameStr.str()),
160                      true);
161      }
162      SymToPrint = StubSym.getPointer();
163    } else {
164      SymToPrint = GetExternalSymbolSymbol(MO.getSymbolName());
165    }
166
167    // If the name begins with a dollar-sign, enclose it in parens.  We do this
168    // to avoid having it look like an integer immediate to the assembler.
169    if (SymToPrint->getName()[0] != '$')
170      O << *SymToPrint;
171    else
172      O << '(' << *SymToPrint << '(';
173    break;
174  }
175  }
176
177  switch (MO.getTargetFlags()) {
178  default:
179    llvm_unreachable("Unknown target flag on GV operand");
180  case X86II::MO_NO_FLAG:    // No flag.
181    break;
182  case X86II::MO_DARWIN_NONLAZY:
183  case X86II::MO_DLLIMPORT:
184  case X86II::MO_DARWIN_STUB:
185    // These affect the name of the symbol, not any suffix.
186    break;
187  case X86II::MO_GOT_ABSOLUTE_ADDRESS:
188    O << " + [.-";
189    PrintPICBaseSymbol(O);
190    O << ']';
191    break;
192  case X86II::MO_PIC_BASE_OFFSET:
193  case X86II::MO_DARWIN_NONLAZY_PIC_BASE:
194  case X86II::MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE:
195    O << '-';
196    PrintPICBaseSymbol(O);
197    break;
198  case X86II::MO_TLSGD:     O << "@TLSGD";     break;
199  case X86II::MO_GOTTPOFF:  O << "@GOTTPOFF";  break;
200  case X86II::MO_INDNTPOFF: O << "@INDNTPOFF"; break;
201  case X86II::MO_TPOFF:     O << "@TPOFF";     break;
202  case X86II::MO_NTPOFF:    O << "@NTPOFF";    break;
203  case X86II::MO_GOTPCREL:  O << "@GOTPCREL";  break;
204  case X86II::MO_GOT:       O << "@GOT";       break;
205  case X86II::MO_GOTOFF:    O << "@GOTOFF";    break;
206  case X86II::MO_PLT:       O << "@PLT";       break;
207  case X86II::MO_TLVP:      O << "@TLVP";      break;
208  case X86II::MO_TLVP_PIC_BASE:
209    O << "@TLVP" << '-';
210    PrintPICBaseSymbol(O);
211    break;
212  }
213}
214
215/// print_pcrel_imm - This is used to print an immediate value that ends up
216/// being encoded as a pc-relative value.  These print slightly differently, for
217/// example, a $ is not emitted.
218void X86AsmPrinter::print_pcrel_imm(const MachineInstr *MI, unsigned OpNo,
219                                    raw_ostream &O) {
220  const MachineOperand &MO = MI->getOperand(OpNo);
221  switch (MO.getType()) {
222  default: llvm_unreachable("Unknown pcrel immediate operand");
223  case MachineOperand::MO_Register:
224    // pc-relativeness was handled when computing the value in the reg.
225    printOperand(MI, OpNo, O);
226    return;
227  case MachineOperand::MO_Immediate:
228    O << MO.getImm();
229    return;
230  case MachineOperand::MO_MachineBasicBlock:
231    O << *MO.getMBB()->getSymbol();
232    return;
233  case MachineOperand::MO_GlobalAddress:
234  case MachineOperand::MO_ExternalSymbol:
235    printSymbolOperand(MO, O);
236    return;
237  }
238}
239
240
241void X86AsmPrinter::printOperand(const MachineInstr *MI, unsigned OpNo,
242                                 raw_ostream &O, const char *Modifier) {
243  const MachineOperand &MO = MI->getOperand(OpNo);
244  switch (MO.getType()) {
245  default: llvm_unreachable("unknown operand type!");
246  case MachineOperand::MO_Register: {
247    O << '%';
248    unsigned Reg = MO.getReg();
249    if (Modifier && strncmp(Modifier, "subreg", strlen("subreg")) == 0) {
250      EVT VT = (strcmp(Modifier+6,"64") == 0) ?
251        MVT::i64 : ((strcmp(Modifier+6, "32") == 0) ? MVT::i32 :
252                    ((strcmp(Modifier+6,"16") == 0) ? MVT::i16 : MVT::i8));
253      Reg = getX86SubSuperRegister(Reg, VT);
254    }
255    O << X86ATTInstPrinter::getRegisterName(Reg);
256    return;
257  }
258
259  case MachineOperand::MO_Immediate:
260    O << '$' << MO.getImm();
261    return;
262
263  case MachineOperand::MO_JumpTableIndex:
264  case MachineOperand::MO_ConstantPoolIndex:
265  case MachineOperand::MO_GlobalAddress:
266  case MachineOperand::MO_ExternalSymbol: {
267    O << '$';
268    printSymbolOperand(MO, O);
269    break;
270  }
271  }
272}
273
274void X86AsmPrinter::printSSECC(const MachineInstr *MI, unsigned Op,
275                               raw_ostream &O) {
276  unsigned char value = MI->getOperand(Op).getImm();
277  assert(value <= 7 && "Invalid ssecc argument!");
278  switch (value) {
279  case 0: O << "eq"; break;
280  case 1: O << "lt"; break;
281  case 2: O << "le"; break;
282  case 3: O << "unord"; break;
283  case 4: O << "neq"; break;
284  case 5: O << "nlt"; break;
285  case 6: O << "nle"; break;
286  case 7: O << "ord"; break;
287  }
288}
289
290void X86AsmPrinter::printLeaMemReference(const MachineInstr *MI, unsigned Op,
291                                         raw_ostream &O, const char *Modifier) {
292  const MachineOperand &BaseReg  = MI->getOperand(Op);
293  const MachineOperand &IndexReg = MI->getOperand(Op+2);
294  const MachineOperand &DispSpec = MI->getOperand(Op+3);
295
296  // If we really don't want to print out (rip), don't.
297  bool HasBaseReg = BaseReg.getReg() != 0;
298  if (HasBaseReg && Modifier && !strcmp(Modifier, "no-rip") &&
299      BaseReg.getReg() == X86::RIP)
300    HasBaseReg = false;
301
302  // HasParenPart - True if we will print out the () part of the mem ref.
303  bool HasParenPart = IndexReg.getReg() || HasBaseReg;
304
305  if (DispSpec.isImm()) {
306    int DispVal = DispSpec.getImm();
307    if (DispVal || !HasParenPart)
308      O << DispVal;
309  } else {
310    assert(DispSpec.isGlobal() || DispSpec.isCPI() ||
311           DispSpec.isJTI() || DispSpec.isSymbol());
312    printSymbolOperand(MI->getOperand(Op+3), O);
313  }
314
315  if (HasParenPart) {
316    assert(IndexReg.getReg() != X86::ESP &&
317           "X86 doesn't allow scaling by ESP");
318
319    O << '(';
320    if (HasBaseReg)
321      printOperand(MI, Op, O, Modifier);
322
323    if (IndexReg.getReg()) {
324      O << ',';
325      printOperand(MI, Op+2, O, Modifier);
326      unsigned ScaleVal = MI->getOperand(Op+1).getImm();
327      if (ScaleVal != 1)
328        O << ',' << ScaleVal;
329    }
330    O << ')';
331  }
332}
333
334void X86AsmPrinter::printMemReference(const MachineInstr *MI, unsigned Op,
335                                      raw_ostream &O, const char *Modifier) {
336  assert(isMem(MI, Op) && "Invalid memory reference!");
337  const MachineOperand &Segment = MI->getOperand(Op+4);
338  if (Segment.getReg()) {
339    printOperand(MI, Op+4, O, Modifier);
340    O << ':';
341  }
342  printLeaMemReference(MI, Op, O, Modifier);
343}
344
345void X86AsmPrinter::printPICLabel(const MachineInstr *MI, unsigned Op,
346                                  raw_ostream &O) {
347  PrintPICBaseSymbol(O);
348  O << '\n';
349  PrintPICBaseSymbol(O);
350  O << ':';
351}
352
353bool X86AsmPrinter::printAsmMRegister(const MachineOperand &MO, char Mode,
354                                      raw_ostream &O) {
355  unsigned Reg = MO.getReg();
356  switch (Mode) {
357  default: return true;  // Unknown mode.
358  case 'b': // Print QImode register
359    Reg = getX86SubSuperRegister(Reg, MVT::i8);
360    break;
361  case 'h': // Print QImode high register
362    Reg = getX86SubSuperRegister(Reg, MVT::i8, true);
363    break;
364  case 'w': // Print HImode register
365    Reg = getX86SubSuperRegister(Reg, MVT::i16);
366    break;
367  case 'k': // Print SImode register
368    Reg = getX86SubSuperRegister(Reg, MVT::i32);
369    break;
370  case 'q': // Print DImode register
371    Reg = getX86SubSuperRegister(Reg, MVT::i64);
372    break;
373  }
374
375  O << '%' << X86ATTInstPrinter::getRegisterName(Reg);
376  return false;
377}
378
379/// PrintAsmOperand - Print out an operand for an inline asm expression.
380///
381bool X86AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
382                                    unsigned AsmVariant,
383                                    const char *ExtraCode, raw_ostream &O) {
384  // Does this asm operand have a single letter operand modifier?
385  if (ExtraCode && ExtraCode[0]) {
386    if (ExtraCode[1] != 0) return true; // Unknown modifier.
387
388    const MachineOperand &MO = MI->getOperand(OpNo);
389
390    switch (ExtraCode[0]) {
391    default: return true;  // Unknown modifier.
392    case 'a': // This is an address.  Currently only 'i' and 'r' are expected.
393      if (MO.isImm()) {
394        O << MO.getImm();
395        return false;
396      }
397      if (MO.isGlobal() || MO.isCPI() || MO.isJTI() || MO.isSymbol()) {
398        printSymbolOperand(MO, O);
399        if (Subtarget->isPICStyleRIPRel())
400          O << "(%rip)";
401        return false;
402      }
403      if (MO.isReg()) {
404        O << '(';
405        printOperand(MI, OpNo, O);
406        O << ')';
407        return false;
408      }
409      return true;
410
411    case 'c': // Don't print "$" before a global var name or constant.
412      if (MO.isImm())
413        O << MO.getImm();
414      else if (MO.isGlobal() || MO.isCPI() || MO.isJTI() || MO.isSymbol())
415        printSymbolOperand(MO, O);
416      else
417        printOperand(MI, OpNo, O);
418      return false;
419
420    case 'A': // Print '*' before a register (it must be a register)
421      if (MO.isReg()) {
422        O << '*';
423        printOperand(MI, OpNo, O);
424        return false;
425      }
426      return true;
427
428    case 'b': // Print QImode register
429    case 'h': // Print QImode high register
430    case 'w': // Print HImode register
431    case 'k': // Print SImode register
432    case 'q': // Print DImode register
433      if (MO.isReg())
434        return printAsmMRegister(MO, ExtraCode[0], O);
435      printOperand(MI, OpNo, O);
436      return false;
437
438    case 'P': // This is the operand of a call, treat specially.
439      print_pcrel_imm(MI, OpNo, O);
440      return false;
441
442    case 'n':  // Negate the immediate or print a '-' before the operand.
443      // Note: this is a temporary solution. It should be handled target
444      // independently as part of the 'MC' work.
445      if (MO.isImm()) {
446        O << -MO.getImm();
447        return false;
448      }
449      O << '-';
450    }
451  }
452
453  printOperand(MI, OpNo, O);
454  return false;
455}
456
457bool X86AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
458                                          unsigned OpNo, unsigned AsmVariant,
459                                          const char *ExtraCode,
460                                          raw_ostream &O) {
461  if (ExtraCode && ExtraCode[0]) {
462    if (ExtraCode[1] != 0) return true; // Unknown modifier.
463
464    switch (ExtraCode[0]) {
465    default: return true;  // Unknown modifier.
466    case 'b': // Print QImode register
467    case 'h': // Print QImode high register
468    case 'w': // Print HImode register
469    case 'k': // Print SImode register
470    case 'q': // Print SImode register
471      // These only apply to registers, ignore on mem.
472      break;
473    case 'P': // Don't print @PLT, but do print as memory.
474      printMemReference(MI, OpNo, O, "no-rip");
475      return false;
476    }
477  }
478  printMemReference(MI, OpNo, O);
479  return false;
480}
481
482void X86AsmPrinter::EmitStartOfAsmFile(Module &M) {
483  if (Subtarget->isTargetDarwin())
484    OutStreamer.SwitchSection(getObjFileLowering().getTextSection());
485}
486
487
488void X86AsmPrinter::EmitEndOfAsmFile(Module &M) {
489  if (Subtarget->isTargetDarwin()) {
490    // All darwin targets use mach-o.
491    MachineModuleInfoMachO &MMIMacho =
492      MMI->getObjFileInfo<MachineModuleInfoMachO>();
493
494    // Output stubs for dynamically-linked functions.
495    MachineModuleInfoMachO::SymbolListTy Stubs;
496
497    Stubs = MMIMacho.GetFnStubList();
498    if (!Stubs.empty()) {
499      const MCSection *TheSection =
500        OutContext.getMachOSection("__IMPORT", "__jump_table",
501                                   MCSectionMachO::S_SYMBOL_STUBS |
502                                   MCSectionMachO::S_ATTR_SELF_MODIFYING_CODE |
503                                   MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
504                                   5, SectionKind::getMetadata());
505      OutStreamer.SwitchSection(TheSection);
506
507      for (unsigned i = 0, e = Stubs.size(); i != e; ++i) {
508        // L_foo$stub:
509        OutStreamer.EmitLabel(Stubs[i].first);
510        //   .indirect_symbol _foo
511        OutStreamer.EmitSymbolAttribute(Stubs[i].second.getPointer(),
512                                        MCSA_IndirectSymbol);
513        // hlt; hlt; hlt; hlt; hlt     hlt = 0xf4 = -12.
514        const char HltInsts[] = { -12, -12, -12, -12, -12 };
515        OutStreamer.EmitBytes(StringRef(HltInsts, 5), 0/*addrspace*/);
516      }
517
518      Stubs.clear();
519      OutStreamer.AddBlankLine();
520    }
521
522    // Output stubs for external and common global variables.
523    Stubs = MMIMacho.GetGVStubList();
524    if (!Stubs.empty()) {
525      const MCSection *TheSection =
526        OutContext.getMachOSection("__IMPORT", "__pointers",
527                                   MCSectionMachO::S_NON_LAZY_SYMBOL_POINTERS,
528                                   SectionKind::getMetadata());
529      OutStreamer.SwitchSection(TheSection);
530
531      for (unsigned i = 0, e = Stubs.size(); i != e; ++i) {
532        // L_foo$non_lazy_ptr:
533        OutStreamer.EmitLabel(Stubs[i].first);
534        // .indirect_symbol _foo
535        MachineModuleInfoImpl::StubValueTy &MCSym = Stubs[i].second;
536        OutStreamer.EmitSymbolAttribute(MCSym.getPointer(),
537                                        MCSA_IndirectSymbol);
538        // .long 0
539        if (MCSym.getInt())
540          // External to current translation unit.
541          OutStreamer.EmitIntValue(0, 4/*size*/, 0/*addrspace*/);
542        else
543          // Internal to current translation unit.
544          //
545          // When we place the LSDA into the TEXT section, the type info
546          // pointers need to be indirect and pc-rel. We accomplish this by
547          // using NLPs.  However, sometimes the types are local to the file. So
548          // we need to fill in the value for the NLP in those cases.
549          OutStreamer.EmitValue(MCSymbolRefExpr::Create(MCSym.getPointer(),
550                                                        OutContext),
551                                4/*size*/, 0/*addrspace*/);
552      }
553      Stubs.clear();
554      OutStreamer.AddBlankLine();
555    }
556
557    Stubs = MMIMacho.GetHiddenGVStubList();
558    if (!Stubs.empty()) {
559      OutStreamer.SwitchSection(getObjFileLowering().getDataSection());
560      EmitAlignment(2);
561
562      for (unsigned i = 0, e = Stubs.size(); i != e; ++i) {
563        // L_foo$non_lazy_ptr:
564        OutStreamer.EmitLabel(Stubs[i].first);
565        // .long _foo
566        OutStreamer.EmitValue(MCSymbolRefExpr::
567                              Create(Stubs[i].second.getPointer(),
568                                     OutContext),
569                              4/*size*/, 0/*addrspace*/);
570      }
571      Stubs.clear();
572      OutStreamer.AddBlankLine();
573    }
574
575    // Funny Darwin hack: This flag tells the linker that no global symbols
576    // contain code that falls through to other global symbols (e.g. the obvious
577    // implementation of multiple entry points).  If this doesn't occur, the
578    // linker can safely perform dead code stripping.  Since LLVM never
579    // generates code that does this, it is always safe to set.
580    OutStreamer.EmitAssemblerFlag(MCAF_SubsectionsViaSymbols);
581  }
582
583  if (Subtarget->isTargetCOFF()) {
584    X86COFFMachineModuleInfo &COFFMMI =
585      MMI->getObjFileInfo<X86COFFMachineModuleInfo>();
586
587    // Emit type information for external functions
588    typedef X86COFFMachineModuleInfo::externals_iterator externals_iterator;
589    for (externals_iterator I = COFFMMI.externals_begin(),
590                            E = COFFMMI.externals_end();
591                            I != E; ++I) {
592      OutStreamer.BeginCOFFSymbolDef(CurrentFnSym);
593      OutStreamer.EmitCOFFSymbolStorageClass(COFF::IMAGE_SYM_CLASS_EXTERNAL);
594      OutStreamer.EmitCOFFSymbolType(COFF::IMAGE_SYM_DTYPE_FUNCTION
595                                               << COFF::SCT_COMPLEX_TYPE_SHIFT);
596      OutStreamer.EndCOFFSymbolDef();
597    }
598
599    // Necessary for dllexport support
600    std::vector<const MCSymbol*> DLLExportedFns, DLLExportedGlobals;
601
602    const TargetLoweringObjectFileCOFF &TLOFCOFF =
603      static_cast<const TargetLoweringObjectFileCOFF&>(getObjFileLowering());
604
605    for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I)
606      if (I->hasDLLExportLinkage())
607        DLLExportedFns.push_back(Mang->getSymbol(I));
608
609    for (Module::const_global_iterator I = M.global_begin(),
610           E = M.global_end(); I != E; ++I)
611      if (I->hasDLLExportLinkage())
612        DLLExportedGlobals.push_back(Mang->getSymbol(I));
613
614    // Output linker support code for dllexported globals on windows.
615    if (!DLLExportedGlobals.empty() || !DLLExportedFns.empty()) {
616      OutStreamer.SwitchSection(TLOFCOFF.getDrectveSection());
617      SmallString<128> name;
618      for (unsigned i = 0, e = DLLExportedGlobals.size(); i != e; ++i) {
619        if (Subtarget->isTargetWindows())
620          name = " /EXPORT:";
621        else
622          name = " -export:";
623        name += DLLExportedGlobals[i]->getName();
624        if (Subtarget->isTargetWindows())
625          name += ",DATA";
626        else
627        name += ",data";
628        OutStreamer.EmitBytes(name, 0);
629      }
630
631      for (unsigned i = 0, e = DLLExportedFns.size(); i != e; ++i) {
632        if (Subtarget->isTargetWindows())
633          name = " /EXPORT:";
634        else
635          name = " -export:";
636        name += DLLExportedFns[i]->getName();
637        OutStreamer.EmitBytes(name, 0);
638      }
639    }
640  }
641
642  if (Subtarget->isTargetELF()) {
643    const TargetLoweringObjectFileELF &TLOFELF =
644      static_cast<const TargetLoweringObjectFileELF &>(getObjFileLowering());
645
646    MachineModuleInfoELF &MMIELF = MMI->getObjFileInfo<MachineModuleInfoELF>();
647
648    // Output stubs for external and common global variables.
649    MachineModuleInfoELF::SymbolListTy Stubs = MMIELF.GetGVStubList();
650    if (!Stubs.empty()) {
651      OutStreamer.SwitchSection(TLOFELF.getDataRelSection());
652      const TargetData *TD = TM.getTargetData();
653
654      for (unsigned i = 0, e = Stubs.size(); i != e; ++i) {
655        OutStreamer.EmitLabel(Stubs[i].first);
656        OutStreamer.EmitSymbolValue(Stubs[i].second.getPointer(),
657                                    TD->getPointerSize(), 0);
658      }
659      Stubs.clear();
660    }
661  }
662}
663
664MachineLocation
665X86AsmPrinter::getDebugValueLocation(const MachineInstr *MI) const {
666  MachineLocation Location;
667  assert (MI->getNumOperands() == 7 && "Invalid no. of machine operands!");
668  // Frame address.  Currently handles register +- offset only.
669
670  if (MI->getOperand(0).isReg() && MI->getOperand(3).isImm())
671    Location.set(MI->getOperand(0).getReg(), MI->getOperand(3).getImm());
672  else {
673    DEBUG(dbgs() << "DBG_VALUE instruction ignored! " << *MI << "\n");
674  }
675  return Location;
676}
677
678void X86AsmPrinter::PrintDebugValueComment(const MachineInstr *MI,
679                                           raw_ostream &O) {
680  // Only the target-dependent form of DBG_VALUE should get here.
681  // Referencing the offset and metadata as NOps-2 and NOps-1 is
682  // probably portable to other targets; frame pointer location is not.
683  unsigned NOps = MI->getNumOperands();
684  assert(NOps==7);
685  O << '\t' << MAI->getCommentString() << "DEBUG_VALUE: ";
686  // cast away const; DIetc do not take const operands for some reason.
687  DIVariable V(const_cast<MDNode *>(MI->getOperand(NOps-1).getMetadata()));
688  if (V.getContext().isSubprogram())
689    O << DISubprogram(V.getContext()).getDisplayName() << ":";
690  O << V.getName();
691  O << " <- ";
692  // Frame address.  Currently handles register +- offset only.
693  O << '[';
694  if (MI->getOperand(0).isReg() && MI->getOperand(0).getReg())
695    printOperand(MI, 0, O);
696  else
697    O << "undef";
698  O << '+'; printOperand(MI, 3, O);
699  O << ']';
700  O << "+";
701  printOperand(MI, NOps-2, O);
702}
703
704
705
706//===----------------------------------------------------------------------===//
707// Target Registry Stuff
708//===----------------------------------------------------------------------===//
709
710static MCInstPrinter *createX86MCInstPrinter(const Target &T,
711                                             unsigned SyntaxVariant,
712                                             const MCAsmInfo &MAI) {
713  if (SyntaxVariant == 0)
714    return new X86ATTInstPrinter(MAI);
715  if (SyntaxVariant == 1)
716    return new X86IntelInstPrinter(MAI);
717  return 0;
718}
719
720// Force static initialization.
721extern "C" void LLVMInitializeX86AsmPrinter() {
722  RegisterAsmPrinter<X86AsmPrinter> X(TheX86_32Target);
723  RegisterAsmPrinter<X86AsmPrinter> Y(TheX86_64Target);
724
725  TargetRegistry::RegisterMCInstPrinter(TheX86_32Target,createX86MCInstPrinter);
726  TargetRegistry::RegisterMCInstPrinter(TheX86_64Target,createX86MCInstPrinter);
727}
728