LLVM API Documentation

AsmPrinter.cpp

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00001 //===-- AsmPrinter.cpp - Common AsmPrinter code ---------------------------===//
00002 //
00003 //                     The LLVM Compiler Infrastructure
00004 //
00005 // This file was developed by the LLVM research group and is distributed under
00006 // the University of Illinois Open Source License. See LICENSE.TXT for details.
00007 //
00008 //===----------------------------------------------------------------------===//
00009 //
00010 // This file implements the AsmPrinter class.
00011 //
00012 //===----------------------------------------------------------------------===//
00013 
00014 #include "llvm/CodeGen/AsmPrinter.h"
00015 #include "llvm/Assembly/Writer.h"
00016 #include "llvm/DerivedTypes.h"
00017 #include "llvm/Constants.h"
00018 #include "llvm/Module.h"
00019 #include "llvm/CodeGen/MachineConstantPool.h"
00020 #include "llvm/Support/Mangler.h"
00021 #include "llvm/Support/MathExtras.h"
00022 #include "llvm/Target/TargetMachine.h"
00023 #include <iostream>
00024 #include <cerrno>
00025 using namespace llvm;
00026 
00027 AsmPrinter::AsmPrinter(std::ostream &o, TargetMachine &tm)
00028 : FunctionNumber(0), O(o), TM(tm),
00029   CommentString("#"),
00030   GlobalPrefix(""),
00031   PrivateGlobalPrefix("."),
00032   GlobalVarAddrPrefix(""),
00033   GlobalVarAddrSuffix(""),
00034   FunctionAddrPrefix(""),
00035   FunctionAddrSuffix(""),
00036   InlineAsmStart("#APP\n"),
00037   InlineAsmEnd("#NO_APP\n"),
00038   ZeroDirective("\t.zero\t"),
00039   AsciiDirective("\t.ascii\t"),
00040   AscizDirective("\t.asciz\t"),
00041   Data8bitsDirective("\t.byte\t"),
00042   Data16bitsDirective("\t.short\t"),
00043   Data32bitsDirective("\t.long\t"),
00044   Data64bitsDirective("\t.quad\t"),
00045   AlignDirective("\t.align\t"),
00046   AlignmentIsInBytes(true),
00047   SwitchToSectionDirective("\t.section\t"),
00048   ConstantPoolSection("\t.section .rodata\n"),
00049   StaticCtorsSection("\t.section .ctors,\"aw\",@progbits"),
00050   StaticDtorsSection("\t.section .dtors,\"aw\",@progbits"),
00051   LCOMMDirective(0),
00052   COMMDirective("\t.comm\t"),
00053   COMMDirectiveTakesAlignment(true),
00054   HasDotTypeDotSizeDirective(true) {
00055 }
00056 
00057 
00058 /// SwitchSection - Switch to the specified section of the executable if we
00059 /// are not already in it!
00060 ///
00061 void AsmPrinter::SwitchSection(const char *NewSection, const GlobalValue *GV) {
00062   std::string NS;
00063   
00064   if (GV && GV->hasSection())
00065     NS = SwitchToSectionDirective + GV->getSection();
00066   else
00067     NS = std::string("\t")+NewSection;
00068   
00069   if (CurrentSection != NS) {
00070     CurrentSection = NS;
00071     if (!CurrentSection.empty())
00072       O << CurrentSection << '\n';
00073   }
00074 }
00075 
00076 bool AsmPrinter::doInitialization(Module &M) {
00077   Mang = new Mangler(M, GlobalPrefix);
00078   
00079   if (!M.getModuleInlineAsm().empty())
00080     O << CommentString << " Start of file scope inline assembly\n"
00081       << M.getModuleInlineAsm()
00082       << "\n" << CommentString << " End of file scope inline assembly\n";
00083 
00084   SwitchSection("", 0);   // Reset back to no section.
00085   
00086   if (MachineDebugInfo *DebugInfo = getAnalysisToUpdate<MachineDebugInfo>()) {
00087     DebugInfo->AnalyzeModule(M);
00088   }
00089   
00090   return false;
00091 }
00092 
00093 bool AsmPrinter::doFinalization(Module &M) {
00094   delete Mang; Mang = 0;
00095   return false;
00096 }
00097 
00098 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
00099   // What's my mangled name?
00100   CurrentFnName = Mang->getValueName(MF.getFunction());
00101   IncrementFunctionNumber();
00102 }
00103 
00104 /// EmitConstantPool - Print to the current output stream assembly
00105 /// representations of the constants in the constant pool MCP. This is
00106 /// used to print out constants which have been "spilled to memory" by
00107 /// the code generator.
00108 ///
00109 void AsmPrinter::EmitConstantPool(MachineConstantPool *MCP) {
00110   const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
00111   if (CP.empty()) return;
00112   const TargetData &TD = TM.getTargetData();
00113   
00114   SwitchSection(ConstantPoolSection, 0);
00115   EmitAlignment(MCP->getConstantPoolAlignment());
00116   for (unsigned i = 0, e = CP.size(); i != e; ++i) {
00117     O << PrivateGlobalPrefix << "CPI" << getFunctionNumber() << '_' << i
00118       << ":\t\t\t\t\t" << CommentString << " ";
00119     WriteTypeSymbolic(O, CP[i].Val->getType(), 0) << '\n';
00120     EmitGlobalConstant(CP[i].Val);
00121     if (i != e-1) {
00122       unsigned EntSize = TM.getTargetData().getTypeSize(CP[i].Val->getType());
00123       unsigned ValEnd = CP[i].Offset + EntSize;
00124       // Emit inter-object padding for alignment.
00125       EmitZeros(CP[i+1].Offset-ValEnd);
00126     }
00127   }
00128 }
00129 
00130 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
00131 /// special global used by LLVM.  If so, emit it and return true, otherwise
00132 /// do nothing and return false.
00133 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
00134   // Ignore debug and non-emitted data.
00135   if (GV->getSection() == "llvm.metadata") return true;
00136   
00137   if (!GV->hasAppendingLinkage()) return false;
00138 
00139   assert(GV->hasInitializer() && "Not a special LLVM global!");
00140   
00141   if (GV->getName() == "llvm.used")
00142     return true;  // No need to emit this at all.
00143 
00144   if (GV->getName() == "llvm.global_ctors" && GV->use_empty()) {
00145     SwitchSection(StaticCtorsSection, 0);
00146     EmitAlignment(2, 0);
00147     EmitXXStructorList(GV->getInitializer());
00148     return true;
00149   } 
00150   
00151   if (GV->getName() == "llvm.global_dtors" && GV->use_empty()) {
00152     SwitchSection(StaticDtorsSection, 0);
00153     EmitAlignment(2, 0);
00154     EmitXXStructorList(GV->getInitializer());
00155     return true;
00156   }
00157   
00158   return false;
00159 }
00160 
00161 /// EmitXXStructorList - Emit the ctor or dtor list.  This just prints out the 
00162 /// function pointers, ignoring the init priority.
00163 void AsmPrinter::EmitXXStructorList(Constant *List) {
00164   // Should be an array of '{ int, void ()* }' structs.  The first value is the
00165   // init priority, which we ignore.
00166   if (!isa<ConstantArray>(List)) return;
00167   ConstantArray *InitList = cast<ConstantArray>(List);
00168   for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
00169     if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
00170       if (CS->getNumOperands() != 2) return;  // Not array of 2-element structs.
00171 
00172       if (CS->getOperand(1)->isNullValue())
00173         return;  // Found a null terminator, exit printing.
00174       // Emit the function pointer.
00175       EmitGlobalConstant(CS->getOperand(1));
00176     }
00177 }
00178 
00179 /// getPreferredAlignmentLog - Return the preferred alignment of the
00180 /// specified global, returned in log form.  This includes an explicitly
00181 /// requested alignment (if the global has one).
00182 unsigned AsmPrinter::getPreferredAlignmentLog(const GlobalVariable *GV) const {
00183   unsigned Alignment = TM.getTargetData().getTypeAlignmentShift(GV->getType());
00184   if (GV->getAlignment() > (1U << Alignment))
00185     Alignment = Log2_32(GV->getAlignment());
00186   
00187   if (GV->hasInitializer()) {
00188     // Always round up alignment of global doubles to 8 bytes.
00189     if (GV->getType()->getElementType() == Type::DoubleTy && Alignment < 3)
00190       Alignment = 3;
00191     if (Alignment < 4) {
00192       // If the global is not external, see if it is large.  If so, give it a
00193       // larger alignment.
00194       if (TM.getTargetData().getTypeSize(GV->getType()->getElementType()) > 128)
00195         Alignment = 4;    // 16-byte alignment.
00196     }
00197   }
00198   return Alignment;
00199 }
00200 
00201 // EmitAlignment - Emit an alignment directive to the specified power of two.
00202 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const {
00203   if (GV && GV->getAlignment())
00204     NumBits = Log2_32(GV->getAlignment());
00205   if (NumBits == 0) return;   // No need to emit alignment.
00206   if (AlignmentIsInBytes) NumBits = 1 << NumBits;
00207   O << AlignDirective << NumBits << "\n";
00208 }
00209 
00210 /// EmitZeros - Emit a block of zeros.
00211 ///
00212 void AsmPrinter::EmitZeros(uint64_t NumZeros) const {
00213   if (NumZeros) {
00214     if (ZeroDirective)
00215       O << ZeroDirective << NumZeros << "\n";
00216     else {
00217       for (; NumZeros; --NumZeros)
00218         O << Data8bitsDirective << "0\n";
00219     }
00220   }
00221 }
00222 
00223 // Print out the specified constant, without a storage class.  Only the
00224 // constants valid in constant expressions can occur here.
00225 void AsmPrinter::EmitConstantValueOnly(const Constant *CV) {
00226   if (CV->isNullValue() || isa<UndefValue>(CV))
00227     O << "0";
00228   else if (const ConstantBool *CB = dyn_cast<ConstantBool>(CV)) {
00229     assert(CB == ConstantBool::True);
00230     O << "1";
00231   } else if (const ConstantSInt *CI = dyn_cast<ConstantSInt>(CV))
00232     if (((CI->getValue() << 32) >> 32) == CI->getValue())
00233       O << CI->getValue();
00234     else
00235       O << (uint64_t)CI->getValue();
00236   else if (const ConstantUInt *CI = dyn_cast<ConstantUInt>(CV))
00237     O << CI->getValue();
00238   else if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV)) {
00239     // This is a constant address for a global variable or function. Use the
00240     // name of the variable or function as the address value, possibly
00241     // decorating it with GlobalVarAddrPrefix/Suffix or
00242     // FunctionAddrPrefix/Suffix (these all default to "" )
00243     if (isa<Function>(GV))
00244       O << FunctionAddrPrefix << Mang->getValueName(GV) << FunctionAddrSuffix;
00245     else
00246       O << GlobalVarAddrPrefix << Mang->getValueName(GV) << GlobalVarAddrSuffix;
00247   } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
00248     const TargetData &TD = TM.getTargetData();
00249     switch(CE->getOpcode()) {
00250     case Instruction::GetElementPtr: {
00251       // generate a symbolic expression for the byte address
00252       const Constant *ptrVal = CE->getOperand(0);
00253       std::vector<Value*> idxVec(CE->op_begin()+1, CE->op_end());
00254       if (int64_t Offset = TD.getIndexedOffset(ptrVal->getType(), idxVec)) {
00255         if (Offset)
00256           O << "(";
00257         EmitConstantValueOnly(ptrVal);
00258         if (Offset > 0)
00259           O << ") + " << Offset;
00260         else if (Offset < 0)
00261           O << ") - " << -Offset;
00262       } else {
00263         EmitConstantValueOnly(ptrVal);
00264       }
00265       break;
00266     }
00267     case Instruction::Cast: {
00268       // Support only non-converting or widening casts for now, that is, ones
00269       // that do not involve a change in value.  This assertion is really gross,
00270       // and may not even be a complete check.
00271       Constant *Op = CE->getOperand(0);
00272       const Type *OpTy = Op->getType(), *Ty = CE->getType();
00273 
00274       // Remember, kids, pointers can be losslessly converted back and forth
00275       // into 32-bit or wider integers, regardless of signedness. :-P
00276       assert(((isa<PointerType>(OpTy)
00277                && (Ty == Type::LongTy || Ty == Type::ULongTy
00278                    || Ty == Type::IntTy || Ty == Type::UIntTy))
00279               || (isa<PointerType>(Ty)
00280                   && (OpTy == Type::LongTy || OpTy == Type::ULongTy
00281                       || OpTy == Type::IntTy || OpTy == Type::UIntTy))
00282               || (((TD.getTypeSize(Ty) >= TD.getTypeSize(OpTy))
00283                    && OpTy->isLosslesslyConvertibleTo(Ty))))
00284              && "FIXME: Don't yet support this kind of constant cast expr");
00285       EmitConstantValueOnly(Op);
00286       break;
00287     }
00288     case Instruction::Add:
00289       O << "(";
00290       EmitConstantValueOnly(CE->getOperand(0));
00291       O << ") + (";
00292       EmitConstantValueOnly(CE->getOperand(1));
00293       O << ")";
00294       break;
00295     default:
00296       assert(0 && "Unsupported operator!");
00297     }
00298   } else {
00299     assert(0 && "Unknown constant value!");
00300   }
00301 }
00302 
00303 /// toOctal - Convert the low order bits of X into an octal digit.
00304 ///
00305 static inline char toOctal(int X) {
00306   return (X&7)+'0';
00307 }
00308 
00309 /// printAsCString - Print the specified array as a C compatible string, only if
00310 /// the predicate isString is true.
00311 ///
00312 static void printAsCString(std::ostream &O, const ConstantArray *CVA,
00313                            unsigned LastElt) {
00314   assert(CVA->isString() && "Array is not string compatible!");
00315 
00316   O << "\"";
00317   for (unsigned i = 0; i != LastElt; ++i) {
00318     unsigned char C =
00319         (unsigned char)cast<ConstantInt>(CVA->getOperand(i))->getRawValue();
00320 
00321     if (C == '"') {
00322       O << "\\\"";
00323     } else if (C == '\\') {
00324       O << "\\\\";
00325     } else if (isprint(C)) {
00326       O << C;
00327     } else {
00328       switch(C) {
00329       case '\b': O << "\\b"; break;
00330       case '\f': O << "\\f"; break;
00331       case '\n': O << "\\n"; break;
00332       case '\r': O << "\\r"; break;
00333       case '\t': O << "\\t"; break;
00334       default:
00335         O << '\\';
00336         O << toOctal(C >> 6);
00337         O << toOctal(C >> 3);
00338         O << toOctal(C >> 0);
00339         break;
00340       }
00341     }
00342   }
00343   O << "\"";
00344 }
00345 
00346 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
00347 ///
00348 void AsmPrinter::EmitGlobalConstant(const Constant *CV) {
00349   const TargetData &TD = TM.getTargetData();
00350 
00351   if (CV->isNullValue() || isa<UndefValue>(CV)) {
00352     EmitZeros(TD.getTypeSize(CV->getType()));
00353     return;
00354   } else if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV)) {
00355     if (CVA->isString()) {
00356       unsigned NumElts = CVA->getNumOperands();
00357       if (AscizDirective && NumElts && 
00358           cast<ConstantInt>(CVA->getOperand(NumElts-1))->getRawValue() == 0) {
00359         O << AscizDirective;
00360         printAsCString(O, CVA, NumElts-1);
00361       } else {
00362         O << AsciiDirective;
00363         printAsCString(O, CVA, NumElts);
00364       }
00365       O << "\n";
00366     } else { // Not a string.  Print the values in successive locations
00367       for (unsigned i = 0, e = CVA->getNumOperands(); i != e; ++i)
00368         EmitGlobalConstant(CVA->getOperand(i));
00369     }
00370     return;
00371   } else if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV)) {
00372     // Print the fields in successive locations. Pad to align if needed!
00373     const StructLayout *cvsLayout = TD.getStructLayout(CVS->getType());
00374     uint64_t sizeSoFar = 0;
00375     for (unsigned i = 0, e = CVS->getNumOperands(); i != e; ++i) {
00376       const Constant* field = CVS->getOperand(i);
00377 
00378       // Check if padding is needed and insert one or more 0s.
00379       uint64_t fieldSize = TD.getTypeSize(field->getType());
00380       uint64_t padSize = ((i == e-1? cvsLayout->StructSize
00381                            : cvsLayout->MemberOffsets[i+1])
00382                           - cvsLayout->MemberOffsets[i]) - fieldSize;
00383       sizeSoFar += fieldSize + padSize;
00384 
00385       // Now print the actual field value
00386       EmitGlobalConstant(field);
00387 
00388       // Insert the field padding unless it's zero bytes...
00389       EmitZeros(padSize);
00390     }
00391     assert(sizeSoFar == cvsLayout->StructSize &&
00392            "Layout of constant struct may be incorrect!");
00393     return;
00394   } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV)) {
00395     // FP Constants are printed as integer constants to avoid losing
00396     // precision...
00397     double Val = CFP->getValue();
00398     if (CFP->getType() == Type::DoubleTy) {
00399       if (Data64bitsDirective)
00400         O << Data64bitsDirective << DoubleToBits(Val) << "\t" << CommentString
00401           << " double value: " << Val << "\n";
00402       else if (TD.isBigEndian()) {
00403         O << Data32bitsDirective << unsigned(DoubleToBits(Val) >> 32)
00404           << "\t" << CommentString << " double most significant word "
00405           << Val << "\n";
00406         O << Data32bitsDirective << unsigned(DoubleToBits(Val))
00407           << "\t" << CommentString << " double least significant word "
00408           << Val << "\n";
00409       } else {
00410         O << Data32bitsDirective << unsigned(DoubleToBits(Val))
00411           << "\t" << CommentString << " double least significant word " << Val
00412           << "\n";
00413         O << Data32bitsDirective << unsigned(DoubleToBits(Val) >> 32)
00414           << "\t" << CommentString << " double most significant word " << Val
00415           << "\n";
00416       }
00417       return;
00418     } else {
00419       O << Data32bitsDirective << FloatToBits(Val) << "\t" << CommentString
00420         << " float " << Val << "\n";
00421       return;
00422     }
00423   } else if (CV->getType() == Type::ULongTy || CV->getType() == Type::LongTy) {
00424     if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
00425       uint64_t Val = CI->getRawValue();
00426 
00427       if (Data64bitsDirective)
00428         O << Data64bitsDirective << Val << "\n";
00429       else if (TD.isBigEndian()) {
00430         O << Data32bitsDirective << unsigned(Val >> 32)
00431           << "\t" << CommentString << " Double-word most significant word "
00432           << Val << "\n";
00433         O << Data32bitsDirective << unsigned(Val)
00434           << "\t" << CommentString << " Double-word least significant word "
00435           << Val << "\n";
00436       } else {
00437         O << Data32bitsDirective << unsigned(Val)
00438           << "\t" << CommentString << " Double-word least significant word "
00439           << Val << "\n";
00440         O << Data32bitsDirective << unsigned(Val >> 32)
00441           << "\t" << CommentString << " Double-word most significant word "
00442           << Val << "\n";
00443       }
00444       return;
00445     }
00446   } else if (const ConstantPacked *CP = dyn_cast<ConstantPacked>(CV)) {
00447     const PackedType *PTy = CP->getType();
00448     
00449     for (unsigned I = 0, E = PTy->getNumElements(); I < E; ++I)
00450       EmitGlobalConstant(CP->getOperand(I));
00451     
00452     return;
00453   }
00454 
00455   const Type *type = CV->getType();
00456   switch (type->getTypeID()) {
00457   case Type::BoolTyID:
00458   case Type::UByteTyID: case Type::SByteTyID:
00459     O << Data8bitsDirective;
00460     break;
00461   case Type::UShortTyID: case Type::ShortTyID:
00462     O << Data16bitsDirective;
00463     break;
00464   case Type::PointerTyID:
00465     if (TD.getPointerSize() == 8) {
00466       O << Data64bitsDirective;
00467       break;
00468     }
00469     //Fall through for pointer size == int size
00470   case Type::UIntTyID: case Type::IntTyID:
00471     O << Data32bitsDirective;
00472     break;
00473   case Type::ULongTyID: case Type::LongTyID:
00474     assert(Data64bitsDirective &&"Target cannot handle 64-bit constant exprs!");
00475     O << Data64bitsDirective;
00476     break;
00477   case Type::FloatTyID: case Type::DoubleTyID:
00478     assert (0 && "Should have already output floating point constant.");
00479   default:
00480     assert (0 && "Can't handle printing this type of thing");
00481     break;
00482   }
00483   EmitConstantValueOnly(CV);
00484   O << "\n";
00485 }
00486 
00487 /// printInlineAsm - This method formats and prints the specified machine
00488 /// instruction that is an inline asm.
00489 void AsmPrinter::printInlineAsm(const MachineInstr *MI) const {
00490   O << InlineAsmStart;
00491   unsigned NumOperands = MI->getNumOperands();
00492   
00493   // Count the number of register definitions.
00494   unsigned NumDefs = 0;
00495   for (; MI->getOperand(NumDefs).isDef(); ++NumDefs)
00496     assert(NumDefs != NumOperands-1 && "No asm string?");
00497   
00498   assert(MI->getOperand(NumDefs).isExternalSymbol() && "No asm string?");
00499 
00500   // Disassemble the AsmStr, printing out the literal pieces, the operands, etc.
00501   const char *AsmStr = MI->getOperand(NumDefs).getSymbolName();
00502 
00503   // The variant of the current asmprinter: FIXME: change.
00504   int AsmPrinterVariant = 0;
00505   
00506   int CurVariant = -1;            // The number of the {.|.|.} region we are in.
00507   const char *LastEmitted = AsmStr; // One past the last character emitted.
00508   
00509   while (*LastEmitted) {
00510     switch (*LastEmitted) {
00511     default: {
00512       // Not a special case, emit the string section literally.
00513       const char *LiteralEnd = LastEmitted+1;
00514       while (*LiteralEnd && *LiteralEnd != '{' && *LiteralEnd != '|' &&
00515              *LiteralEnd != '}' && *LiteralEnd != '$')
00516         ++LiteralEnd;
00517       if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
00518         O.write(LastEmitted, LiteralEnd-LastEmitted);
00519       LastEmitted = LiteralEnd;
00520       break;
00521     }
00522     case '$': {
00523       ++LastEmitted;   // Consume '$' character.
00524       if (*LastEmitted == '$') { // $$ -> $
00525         if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
00526           O << '$';
00527         ++LastEmitted;  // Consume second '$' character.
00528         break;
00529       }
00530       
00531       bool HasCurlyBraces = false;
00532       if (*LastEmitted == '{') {     // ${variable}
00533         ++LastEmitted;               // Consume '{' character.
00534         HasCurlyBraces = true;
00535       }
00536       
00537       const char *IDStart = LastEmitted;
00538       char *IDEnd;
00539       long Val = strtol(IDStart, &IDEnd, 10); // We only accept numbers for IDs.
00540       if (!isdigit(*IDStart) || (Val == 0 && errno == EINVAL)) {
00541         std::cerr << "Bad $ operand number in inline asm string: '" 
00542                   << AsmStr << "'\n";
00543         exit(1);
00544       }
00545       LastEmitted = IDEnd;
00546       
00547       char Modifier[2] = { 0, 0 };
00548       
00549       if (HasCurlyBraces) {
00550         // If we have curly braces, check for a modifier character.  This
00551         // supports syntax like ${0:u}, which correspond to "%u0" in GCC asm.
00552         if (*LastEmitted == ':') {
00553           ++LastEmitted;    // Consume ':' character.
00554           if (*LastEmitted == 0) {
00555             std::cerr << "Bad ${:} expression in inline asm string: '" 
00556                       << AsmStr << "'\n";
00557             exit(1);
00558           }
00559           
00560           Modifier[0] = *LastEmitted;
00561           ++LastEmitted;    // Consume modifier character.
00562         }
00563         
00564         if (*LastEmitted != '}') {
00565           std::cerr << "Bad ${} expression in inline asm string: '" 
00566                     << AsmStr << "'\n";
00567           exit(1);
00568         }
00569         ++LastEmitted;    // Consume '}' character.
00570       }
00571       
00572       if ((unsigned)Val >= NumOperands-1) {
00573         std::cerr << "Invalid $ operand number in inline asm string: '" 
00574                   << AsmStr << "'\n";
00575         exit(1);
00576       }
00577       
00578       // Okay, we finally have a value number.  Ask the target to print this
00579       // operand!
00580       if (CurVariant == -1 || CurVariant == AsmPrinterVariant) {
00581         unsigned OpNo = 1;
00582         
00583         // Scan to find the machine operand number for the operand.
00584         for (; Val; --Val) {
00585           unsigned OpFlags = MI->getOperand(OpNo).getImmedValue();
00586           OpNo += (OpFlags >> 3) + 1;
00587         }
00588         
00589         unsigned OpFlags = MI->getOperand(OpNo).getImmedValue();
00590         ++OpNo;  // Skip over the ID number.
00591 
00592         bool Error;
00593         AsmPrinter *AP = const_cast<AsmPrinter*>(this);
00594         if ((OpFlags & 7) == 4 /*ADDR MODE*/) {
00595           Error = AP->PrintAsmMemoryOperand(MI, OpNo, AsmPrinterVariant,
00596                                             Modifier[0] ? Modifier : 0);
00597         } else {
00598           Error = AP->PrintAsmOperand(MI, OpNo, AsmPrinterVariant,
00599                                       Modifier[0] ? Modifier : 0);
00600         }
00601         if (Error) {
00602           std::cerr << "Invalid operand found in inline asm: '"
00603                     << AsmStr << "'\n";
00604           MI->dump();
00605           exit(1);
00606         }
00607       }
00608       break;
00609     }
00610     case '{':
00611       ++LastEmitted;      // Consume '{' character.
00612       if (CurVariant != -1) {
00613         std::cerr << "Nested variants found in inline asm string: '"
00614                   << AsmStr << "'\n";
00615         exit(1);
00616       }
00617       CurVariant = 0;     // We're in the first variant now.
00618       break;
00619     case '|':
00620       ++LastEmitted;  // consume '|' character.
00621       if (CurVariant == -1) {
00622         std::cerr << "Found '|' character outside of variant in inline asm "
00623                   << "string: '" << AsmStr << "'\n";
00624         exit(1);
00625       }
00626       ++CurVariant;   // We're in the next variant.
00627       break;
00628     case '}':
00629       ++LastEmitted;  // consume '}' character.
00630       if (CurVariant == -1) {
00631         std::cerr << "Found '}' character outside of variant in inline asm "
00632                   << "string: '" << AsmStr << "'\n";
00633         exit(1);
00634       }
00635       CurVariant = -1;
00636       break;
00637     }
00638   }
00639   O << "\n" << InlineAsmEnd;
00640 }
00641 
00642 /// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
00643 /// instruction, using the specified assembler variant.  Targets should
00644 /// overried this to format as appropriate.
00645 bool AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
00646                                  unsigned AsmVariant, const char *ExtraCode) {
00647   // Target doesn't support this yet!
00648   return true;
00649 }
00650 
00651 bool AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
00652                                        unsigned AsmVariant,
00653                                        const char *ExtraCode) {
00654   // Target doesn't support this yet!
00655   return true;
00656 }