llvm/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp - toolchain/llvm-project - Gitiles

 //===-- AsmPrinterInlineAsm.cpp - AsmPrinter Inline Asm Handling ----------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements the inline assembler pieces of the AsmPrinter class.
 //
 //===----------------------------------------------------------------------===//

 #define DEBUG_TYPE "asm-printer"
 #include "llvm/CodeGen/AsmPrinter.h"
 #include "llvm/ADT/OwningPtr.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/CodeGen/MachineBasicBlock.h"
 #include "llvm/CodeGen/MachineModuleInfo.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/InlineAsm.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Module.h"
 #include "llvm/MC/MCAsmInfo.h"
 #include "llvm/MC/MCStreamer.h"
 #include "llvm/MC/MCSubtargetInfo.h"
 #include "llvm/MC/MCSymbol.h"
 #include "llvm/MC/MCTargetAsmParser.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/SourceMgr.h"
 #include "llvm/Support/TargetRegistry.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Target/TargetMachine.h"
 using namespace llvm;

 namespace {
   struct SrcMgrDiagInfo {
     const MDNode *LocInfo;
     LLVMContext::InlineAsmDiagHandlerTy DiagHandler;
     void *DiagContext;
   };
 }

 /// srcMgrDiagHandler - This callback is invoked when the SourceMgr for an
 /// inline asm has an error in it.  diagInfo is a pointer to the SrcMgrDiagInfo
 /// struct above.
 static void srcMgrDiagHandler(const SMDiagnostic &Diag, void *diagInfo) {
   SrcMgrDiagInfo *DiagInfo = static_cast<SrcMgrDiagInfo *>(diagInfo);
   assert(DiagInfo && "Diagnostic context not passed down?");

   // If the inline asm had metadata associated with it, pull out a location
   // cookie corresponding to which line the error occurred on.
   unsigned LocCookie = 0;
   if (const MDNode *LocInfo = DiagInfo->LocInfo) {
     unsigned ErrorLine = Diag.getLineNo()-1;
     if (ErrorLine >= LocInfo->getNumOperands())
       ErrorLine = 0;

     if (LocInfo->getNumOperands() != 0)
       if (const ConstantInt *CI =
           dyn_cast<ConstantInt>(LocInfo->getOperand(ErrorLine)))
         LocCookie = CI->getZExtValue();
   }

   DiagInfo->DiagHandler(Diag, DiagInfo->DiagContext, LocCookie);
 }

 /// EmitInlineAsm - Emit a blob of inline asm to the output streamer.
 void AsmPrinter::EmitInlineAsm(StringRef Str, const MDNode *LocMDNode,
                                InlineAsm::AsmDialect Dialect) const {
   assert(!Str.empty() && "Can't emit empty inline asm block");

   // Remember if the buffer is nul terminated or not so we can avoid a copy.
   bool isNullTerminated = Str.back() == 0;
   if (isNullTerminated)
     Str = Str.substr(0, Str.size()-1);

   // If the output streamer is actually a .s file, just emit the blob textually.
   // This is useful in case the asm parser doesn't handle something but the
   // system assembler does.
   if (OutStreamer.hasRawTextSupport()) {
     OutStreamer.EmitRawText(Str);
     return;
   }

   SourceMgr SrcMgr;
   SrcMgrDiagInfo DiagInfo;

   // If the current LLVMContext has an inline asm handler, set it in SourceMgr.
   LLVMContext &LLVMCtx = MMI->getModule()->getContext();
   bool HasDiagHandler = false;
   if (LLVMCtx.getInlineAsmDiagnosticHandler() != 0) {
     // If the source manager has an issue, we arrange for srcMgrDiagHandler
     // to be invoked, getting DiagInfo passed into it.
     DiagInfo.LocInfo = LocMDNode;
     DiagInfo.DiagHandler = LLVMCtx.getInlineAsmDiagnosticHandler();
     DiagInfo.DiagContext = LLVMCtx.getInlineAsmDiagnosticContext();
     SrcMgr.setDiagHandler(srcMgrDiagHandler, &DiagInfo);
     HasDiagHandler = true;
   }

   MemoryBuffer *Buffer;
   if (isNullTerminated)
     Buffer = MemoryBuffer::getMemBuffer(Str, "<inline asm>");
   else
     Buffer = MemoryBuffer::getMemBufferCopy(Str, "<inline asm>");

   // Tell SrcMgr about this buffer, it takes ownership of the buffer.
   SrcMgr.AddNewSourceBuffer(Buffer, SMLoc());

   OwningPtr<MCAsmParser> Parser(createMCAsmParser(SrcMgr,
                                                   OutContext, OutStreamer,
                                                   *MAI));

   // FIXME: It would be nice if we can avoid createing a new instance of
   // MCSubtargetInfo here given TargetSubtargetInfo is available. However,
   // we have to watch out for asm directives which can change subtarget
   // state. e.g. .code 16, .code 32.
   OwningPtr<MCSubtargetInfo>
     STI(TM.getTarget().createMCSubtargetInfo(TM.getTargetTriple(),
                                              TM.getTargetCPU(),
                                              TM.getTargetFeatureString()));
   OwningPtr<MCTargetAsmParser>
     TAP(TM.getTarget().createMCAsmParser(*STI, *Parser, *MII));
   if (!TAP)
     report_fatal_error("Inline asm not supported by this streamer because"
                        " we don't have an asm parser for this target\n");
   Parser->setAssemblerDialect(Dialect);
   Parser->setTargetParser(*TAP.get());

   // Don't implicitly switch to the text section before the asm.
   int Res = Parser->Run(/*NoInitialTextSection*/ true,
                         /*NoFinalize*/ true);
   if (Res && !HasDiagHandler)
     report_fatal_error("Error parsing inline asm\n");
 }

 static void EmitMSInlineAsmStr(const char *AsmStr, const MachineInstr *MI,
                                MachineModuleInfo *MMI, int InlineAsmVariant,
                                AsmPrinter *AP, unsigned LocCookie,
                                raw_ostream &OS) {
   // Switch to the inline assembly variant.
   OS << "\t.intel_syntax\n\t";

   const char *LastEmitted = AsmStr; // One past the last character emitted.
   unsigned NumOperands = MI->getNumOperands();

   while (*LastEmitted) {
     switch (*LastEmitted) {
     default: {
       // Not a special case, emit the string section literally.
       const char *LiteralEnd = LastEmitted+1;
       while (*LiteralEnd && *LiteralEnd != '{' && *LiteralEnd != '|' &&
              *LiteralEnd != '}' && *LiteralEnd != '$' && *LiteralEnd != '\n')
         ++LiteralEnd;

       OS.write(LastEmitted, LiteralEnd-LastEmitted);
       LastEmitted = LiteralEnd;
       break;
     }
     case '\n':
       ++LastEmitted;   // Consume newline character.
       OS << '\n';      // Indent code with newline.
       break;
     case '$': {
       ++LastEmitted;   // Consume '$' character.
       bool Done = true;

       // Handle escapes.
       switch (*LastEmitted) {
       default: Done = false; break;
       case '$':
         ++LastEmitted;  // Consume second '$' character.
         break;
       }
       if (Done) break;

       const char *IDStart = LastEmitted;
       const char *IDEnd = IDStart;
       while (*IDEnd >= '0' && *IDEnd <= '9') ++IDEnd;

       unsigned Val;
       if (StringRef(IDStart, IDEnd-IDStart).getAsInteger(10, Val))
         report_fatal_error("Bad $ operand number in inline asm string: '" +
                            Twine(AsmStr) + "'");
       LastEmitted = IDEnd;

       if (Val >= NumOperands-1)
         report_fatal_error("Invalid $ operand number in inline asm string: '" +
                            Twine(AsmStr) + "'");

       // Okay, we finally have a value number.  Ask the target to print this
       // operand!
       unsigned OpNo = InlineAsm::MIOp_FirstOperand;

       bool Error = false;

       // Scan to find the machine operand number for the operand.
       for (; Val; --Val) {
         if (OpNo >= MI->getNumOperands()) break;
         unsigned OpFlags = MI->getOperand(OpNo).getImm();
         OpNo += InlineAsm::getNumOperandRegisters(OpFlags) + 1;
       }

       // We may have a location metadata attached to the end of the
       // instruction, and at no point should see metadata at any
       // other point while processing. It's an error if so.
       if (OpNo >= MI->getNumOperands() ||
           MI->getOperand(OpNo).isMetadata()) {
         Error = true;
       } else {
         unsigned OpFlags = MI->getOperand(OpNo).getImm();
         ++OpNo;  // Skip over the ID number.

         if (InlineAsm::isMemKind(OpFlags)) {
           Error = AP->PrintAsmMemoryOperand(MI, OpNo, InlineAsmVariant,
                                             /*Modifier*/ 0, OS);
         } else {
           Error = AP->PrintAsmOperand(MI, OpNo, InlineAsmVariant,
                                       /*Modifier*/ 0, OS);
         }
       }
       if (Error) {
         std::string msg;
         raw_string_ostream Msg(msg);
         Msg << "invalid operand in inline asm: '" << AsmStr << "'";
         MMI->getModule()->getContext().emitError(LocCookie, Msg.str());
       }
       break;
     }
     }
   }
   OS << "\n\t.att_syntax\n" << (char)0;  // null terminate string.
 }

 static void EmitGCCInlineAsmStr(const char *AsmStr, const MachineInstr *MI,
                                 MachineModuleInfo *MMI, int InlineAsmVariant,
                                 int AsmPrinterVariant, AsmPrinter *AP,
                                 unsigned LocCookie, raw_ostream &OS) {
   int CurVariant = -1;            // The number of the {.|.|.} region we are in.
   const char *LastEmitted = AsmStr; // One past the last character emitted.
   unsigned NumOperands = MI->getNumOperands();

   OS << '\t';

   while (*LastEmitted) {
     switch (*LastEmitted) {
     default: {
       // Not a special case, emit the string section literally.
       const char *LiteralEnd = LastEmitted+1;
       while (*LiteralEnd && *LiteralEnd != '{' && *LiteralEnd != '|' &&
              *LiteralEnd != '}' && *LiteralEnd != '$' && *LiteralEnd != '\n')
         ++LiteralEnd;
       if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
         OS.write(LastEmitted, LiteralEnd-LastEmitted);
       LastEmitted = LiteralEnd;
       break;
     }
     case '\n':
       ++LastEmitted;   // Consume newline character.
       OS << '\n';      // Indent code with newline.
       break;
     case '$': {
       ++LastEmitted;   // Consume '$' character.
       bool Done = true;

       // Handle escapes.
       switch (*LastEmitted) {
       default: Done = false; break;
       case '$':     // $$ -> $
         if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
           OS << '$';
         ++LastEmitted;  // Consume second '$' character.
         break;
       case '(':             // $( -> same as GCC's { character.
         ++LastEmitted;      // Consume '(' character.
         if (CurVariant != -1)
           report_fatal_error("Nested variants found in inline asm string: '" +
                              Twine(AsmStr) + "'");
         CurVariant = 0;     // We're in the first variant now.
         break;
       case '|':
         ++LastEmitted;  // consume '|' character.
         if (CurVariant == -1)
           OS << '|';       // this is gcc's behavior for | outside a variant
         else
           ++CurVariant;   // We're in the next variant.
         break;
       case ')':         // $) -> same as GCC's } char.
         ++LastEmitted;  // consume ')' character.
         if (CurVariant == -1)
           OS << '}';     // this is gcc's behavior for } outside a variant
         else
           CurVariant = -1;
         break;
       }
       if (Done) break;

       bool HasCurlyBraces = false;
       if (*LastEmitted == '{') {     // ${variable}
         ++LastEmitted;               // Consume '{' character.
         HasCurlyBraces = true;
       }

       // If we have ${:foo}, then this is not a real operand reference, it is a
       // "magic" string reference, just like in .td files.  Arrange to call
       // PrintSpecial.
       if (HasCurlyBraces && *LastEmitted == ':') {
         ++LastEmitted;
         const char *StrStart = LastEmitted;
         const char *StrEnd = strchr(StrStart, '}');
         if (StrEnd == 0)
           report_fatal_error("Unterminated ${:foo} operand in inline asm"
                              " string: '" + Twine(AsmStr) + "'");

         std::string Val(StrStart, StrEnd);
         AP->PrintSpecial(MI, OS, Val.c_str());
         LastEmitted = StrEnd+1;
         break;
       }

       const char *IDStart = LastEmitted;
       const char *IDEnd = IDStart;
       while (*IDEnd >= '0' && *IDEnd <= '9') ++IDEnd;

       unsigned Val;
       if (StringRef(IDStart, IDEnd-IDStart).getAsInteger(10, Val))
         report_fatal_error("Bad $ operand number in inline asm string: '" +
                            Twine(AsmStr) + "'");
       LastEmitted = IDEnd;

       char Modifier[2] = { 0, 0 };

       if (HasCurlyBraces) {
         // If we have curly braces, check for a modifier character.  This
         // supports syntax like ${0:u}, which correspond to "%u0" in GCC asm.
         if (*LastEmitted == ':') {
           ++LastEmitted;    // Consume ':' character.
           if (*LastEmitted == 0)
             report_fatal_error("Bad ${:} expression in inline asm string: '" +
                                Twine(AsmStr) + "'");

           Modifier[0] = *LastEmitted;
           ++LastEmitted;    // Consume modifier character.
         }

         if (*LastEmitted != '}')
           report_fatal_error("Bad ${} expression in inline asm string: '" +
                              Twine(AsmStr) + "'");
         ++LastEmitted;    // Consume '}' character.
       }

       if (Val >= NumOperands-1)
         report_fatal_error("Invalid $ operand number in inline asm string: '" +
                            Twine(AsmStr) + "'");

       // Okay, we finally have a value number.  Ask the target to print this
       // operand!
       if (CurVariant == -1 || CurVariant == AsmPrinterVariant) {
         unsigned OpNo = InlineAsm::MIOp_FirstOperand;

         bool Error = false;

         // Scan to find the machine operand number for the operand.
         for (; Val; --Val) {
           if (OpNo >= MI->getNumOperands()) break;
           unsigned OpFlags = MI->getOperand(OpNo).getImm();
           OpNo += InlineAsm::getNumOperandRegisters(OpFlags) + 1;
         }

         // We may have a location metadata attached to the end of the
         // instruction, and at no point should see metadata at any
         // other point while processing. It's an error if so.
         if (OpNo >= MI->getNumOperands() ||
             MI->getOperand(OpNo).isMetadata()) {
           Error = true;
         } else {
           unsigned OpFlags = MI->getOperand(OpNo).getImm();
           ++OpNo;  // Skip over the ID number.

           if (Modifier[0] == 'l')  // labels are target independent
             // FIXME: What if the operand isn't an MBB, report error?
             OS << *MI->getOperand(OpNo).getMBB()->getSymbol();
           else {
             if (InlineAsm::isMemKind(OpFlags)) {
               Error = AP->PrintAsmMemoryOperand(MI, OpNo, InlineAsmVariant,
                                                 Modifier[0] ? Modifier : 0,
                                                 OS);
             } else {
               Error = AP->PrintAsmOperand(MI, OpNo, InlineAsmVariant,
                                           Modifier[0] ? Modifier : 0, OS);
             }
           }
         }
         if (Error) {
           std::string msg;
           raw_string_ostream Msg(msg);
           Msg << "invalid operand in inline asm: '" << AsmStr << "'";
           MMI->getModule()->getContext().emitError(LocCookie, Msg.str());
         }
       }
       break;
     }
     }
   }
   OS << '\n' << (char)0;  // null terminate string.
 }

 /// EmitInlineAsm - This method formats and emits the specified machine
 /// instruction that is an inline asm.
 void AsmPrinter::EmitInlineAsm(const MachineInstr *MI) const {
   assert(MI->isInlineAsm() && "printInlineAsm only works on inline asms");

   // Count the number of register definitions to find the asm string.
   unsigned NumDefs = 0;
   for (; MI->getOperand(NumDefs).isReg() && MI->getOperand(NumDefs).isDef();
        ++NumDefs)
     assert(NumDefs != MI->getNumOperands()-2 && "No asm string?");

   assert(MI->getOperand(NumDefs).isSymbol() && "No asm string?");

   // Disassemble the AsmStr, printing out the literal pieces, the operands, etc.
   const char *AsmStr = MI->getOperand(NumDefs).getSymbolName();

   // If this asmstr is empty, just print the #APP/#NOAPP markers.
   // These are useful to see where empty asm's wound up.
   if (AsmStr[0] == 0) {
     // Don't emit the comments if writing to a .o file.
     if (!OutStreamer.hasRawTextSupport()) return;

     OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
                             MAI->getInlineAsmStart());
     OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
                             MAI->getInlineAsmEnd());
     return;
   }

   // Emit the #APP start marker.  This has to happen even if verbose-asm isn't
   // enabled, so we use EmitRawText.
   if (OutStreamer.hasRawTextSupport())
     OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
                             MAI->getInlineAsmStart());

   // Get the !srcloc metadata node if we have it, and decode the loc cookie from
   // it.
   unsigned LocCookie = 0;
   const MDNode *LocMD = 0;
   for (unsigned i = MI->getNumOperands(); i != 0; --i) {
     if (MI->getOperand(i-1).isMetadata() &&
         (LocMD = MI->getOperand(i-1).getMetadata()) &&
         LocMD->getNumOperands() != 0) {
       if (const ConstantInt *CI = dyn_cast<ConstantInt>(LocMD->getOperand(0))) {
         LocCookie = CI->getZExtValue();
         break;
       }
     }
   }

   // Emit the inline asm to a temporary string so we can emit it through
   // EmitInlineAsm.
   SmallString<256> StringData;
   raw_svector_ostream OS(StringData);

   // The variant of the current asmprinter.
   int AsmPrinterVariant = MAI->getAssemblerDialect();
   InlineAsm::AsmDialect InlineAsmVariant = MI->getInlineAsmDialect();
   AsmPrinter *AP = const_cast<AsmPrinter*>(this);
   if (InlineAsmVariant == InlineAsm::AD_ATT)
     EmitGCCInlineAsmStr(AsmStr, MI, MMI, InlineAsmVariant, AsmPrinterVariant,
                         AP, LocCookie, OS);
   else
     EmitMSInlineAsmStr(AsmStr, MI, MMI, InlineAsmVariant, AP, LocCookie, OS);

   EmitInlineAsm(OS.str(), LocMD, MI->getInlineAsmDialect());

   // Emit the #NOAPP end marker.  This has to happen even if verbose-asm isn't
   // enabled, so we use EmitRawText.
   if (OutStreamer.hasRawTextSupport())
     OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
                             MAI->getInlineAsmEnd());
 }


 /// PrintSpecial - Print information related to the specified machine instr
 /// that is independent of the operand, and may be independent of the instr
 /// itself.  This can be useful for portably encoding the comment character
 /// or other bits of target-specific knowledge into the asmstrings.  The
 /// syntax used is ${:comment}.  Targets can override this to add support
 /// for their own strange codes.
 void AsmPrinter::PrintSpecial(const MachineInstr *MI, raw_ostream &OS,
                               const char *Code) const {
   if (!strcmp(Code, "private")) {
     OS << MAI->getPrivateGlobalPrefix();
   } else if (!strcmp(Code, "comment")) {
     OS << MAI->getCommentString();
   } else if (!strcmp(Code, "uid")) {
     // Comparing the address of MI isn't sufficient, because machineinstrs may
     // be allocated to the same address across functions.

     // If this is a new LastFn instruction, bump the counter.
     if (LastMI != MI || LastFn != getFunctionNumber()) {
       ++Counter;
       LastMI = MI;
       LastFn = getFunctionNumber();
     }
     OS << Counter;
   } else {
     std::string msg;
     raw_string_ostream Msg(msg);
     Msg << "Unknown special formatter '" << Code
          << "' for machine instr: " << *MI;
     report_fatal_error(Msg.str());
   }
 }

 /// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
 /// instruction, using the specified assembler variant.  Targets should
 /// override this to format as appropriate.
 bool AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
                                  unsigned AsmVariant, const char *ExtraCode,
                                  raw_ostream &O) {
   // Does this asm operand have a single letter operand modifier?
   if (ExtraCode && ExtraCode[0]) {
     if (ExtraCode[1] != 0) return true; // Unknown modifier.

     const MachineOperand &MO = MI->getOperand(OpNo);
     switch (ExtraCode[0]) {
     default:
       return true;  // Unknown modifier.
     case 'c': // Substitute immediate value without immediate syntax
       if (MO.getType() != MachineOperand::MO_Immediate)
         return true;
       O << MO.getImm();
       return false;
     case 'n':  // Negate the immediate constant.
       if (MO.getType() != MachineOperand::MO_Immediate)
         return true;
       O << -MO.getImm();
       return false;
     }
   }
   return true;
 }

 bool AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
                                        unsigned AsmVariant,
                                        const char *ExtraCode, raw_ostream &O) {
   // Target doesn't support this yet!
   return true;
 }
	//===-- AsmPrinterInlineAsm.cpp - AsmPrinter Inline Asm Handling ----------===//
	//
	// The LLVM Compiler Infrastructure
	//
	// This file is distributed under the University of Illinois Open Source
	// License. See LICENSE.TXT for details.
	//
	//===----------------------------------------------------------------------===//
	//
	// This file implements the inline assembler pieces of the AsmPrinter class.
	//
	//===----------------------------------------------------------------------===//

	#define DEBUG_TYPE "asm-printer"
	#include "llvm/CodeGen/AsmPrinter.h"
	#include "llvm/ADT/OwningPtr.h"
	#include "llvm/ADT/SmallString.h"
	#include "llvm/ADT/Twine.h"
	#include "llvm/CodeGen/MachineBasicBlock.h"
	#include "llvm/CodeGen/MachineModuleInfo.h"
	#include "llvm/IR/Constants.h"
	#include "llvm/IR/InlineAsm.h"
	#include "llvm/IR/LLVMContext.h"
	#include "llvm/IR/Module.h"
	#include "llvm/MC/MCAsmInfo.h"
	#include "llvm/MC/MCStreamer.h"
	#include "llvm/MC/MCSubtargetInfo.h"
	#include "llvm/MC/MCSymbol.h"
	#include "llvm/MC/MCTargetAsmParser.h"
	#include "llvm/Support/ErrorHandling.h"
	#include "llvm/Support/MemoryBuffer.h"
	#include "llvm/Support/SourceMgr.h"
	#include "llvm/Support/TargetRegistry.h"
	#include "llvm/Support/raw_ostream.h"
	#include "llvm/Target/TargetMachine.h"
	using namespace llvm;

	namespace {
	struct SrcMgrDiagInfo {
	const MDNode *LocInfo;
	LLVMContext::InlineAsmDiagHandlerTy DiagHandler;
	void *DiagContext;
	};
	}

	/// srcMgrDiagHandler - This callback is invoked when the SourceMgr for an
	/// inline asm has an error in it. diagInfo is a pointer to the SrcMgrDiagInfo
	/// struct above.
	static void srcMgrDiagHandler(const SMDiagnostic &Diag, void *diagInfo) {
	SrcMgrDiagInfo DiagInfo = static_cast<SrcMgrDiagInfo >(diagInfo);
	assert(DiagInfo && "Diagnostic context not passed down?");

	// If the inline asm had metadata associated with it, pull out a location
	// cookie corresponding to which line the error occurred on.
	unsigned LocCookie = 0;
	if (const MDNode *LocInfo = DiagInfo->LocInfo) {
	unsigned ErrorLine = Diag.getLineNo()-1;
	if (ErrorLine >= LocInfo->getNumOperands())
	ErrorLine = 0;

	if (LocInfo->getNumOperands() != 0)
	if (const ConstantInt *CI =
	dyn_cast<ConstantInt>(LocInfo->getOperand(ErrorLine)))
	LocCookie = CI->getZExtValue();
	}

	DiagInfo->DiagHandler(Diag, DiagInfo->DiagContext, LocCookie);
	}

	/// EmitInlineAsm - Emit a blob of inline asm to the output streamer.
	void AsmPrinter::EmitInlineAsm(StringRef Str, const MDNode *LocMDNode,
	InlineAsm::AsmDialect Dialect) const {
	assert(!Str.empty() && "Can't emit empty inline asm block");

	// Remember if the buffer is nul terminated or not so we can avoid a copy.
	bool isNullTerminated = Str.back() == 0;
	if (isNullTerminated)
	Str = Str.substr(0, Str.size()-1);

	// If the output streamer is actually a .s file, just emit the blob textually.
	// This is useful in case the asm parser doesn't handle something but the
	// system assembler does.
	if (OutStreamer.hasRawTextSupport()) {
	OutStreamer.EmitRawText(Str);
	return;
	}

	SourceMgr SrcMgr;
	SrcMgrDiagInfo DiagInfo;

	// If the current LLVMContext has an inline asm handler, set it in SourceMgr.
	LLVMContext &LLVMCtx = MMI->getModule()->getContext();
	bool HasDiagHandler = false;
	if (LLVMCtx.getInlineAsmDiagnosticHandler() != 0) {
	// If the source manager has an issue, we arrange for srcMgrDiagHandler
	// to be invoked, getting DiagInfo passed into it.
	DiagInfo.LocInfo = LocMDNode;
	DiagInfo.DiagHandler = LLVMCtx.getInlineAsmDiagnosticHandler();
	DiagInfo.DiagContext = LLVMCtx.getInlineAsmDiagnosticContext();
	SrcMgr.setDiagHandler(srcMgrDiagHandler, &DiagInfo);
	HasDiagHandler = true;
	}

	MemoryBuffer *Buffer;
	if (isNullTerminated)
	Buffer = MemoryBuffer::getMemBuffer(Str, "<inline asm>");
	else
	Buffer = MemoryBuffer::getMemBufferCopy(Str, "<inline asm>");

	// Tell SrcMgr about this buffer, it takes ownership of the buffer.
	SrcMgr.AddNewSourceBuffer(Buffer, SMLoc());

	OwningPtr<MCAsmParser> Parser(createMCAsmParser(SrcMgr,
	OutContext, OutStreamer,
	*MAI));

	// FIXME: It would be nice if we can avoid createing a new instance of
	// MCSubtargetInfo here given TargetSubtargetInfo is available. However,
	// we have to watch out for asm directives which can change subtarget
	// state. e.g. .code 16, .code 32.
	OwningPtr<MCSubtargetInfo>
	STI(TM.getTarget().createMCSubtargetInfo(TM.getTargetTriple(),
	TM.getTargetCPU(),
	TM.getTargetFeatureString()));
	OwningPtr<MCTargetAsmParser>
	TAP(TM.getTarget().createMCAsmParser(STI, Parser, *MII));
	if (!TAP)
	report_fatal_error("Inline asm not supported by this streamer because"
	" we don't have an asm parser for this target\n");
	Parser->setAssemblerDialect(Dialect);
	Parser->setTargetParser(*TAP.get());

	// Don't implicitly switch to the text section before the asm.
	int Res = Parser->Run(/NoInitialTextSection/ true,
	/NoFinalize/ true);
	if (Res && !HasDiagHandler)
	report_fatal_error("Error parsing inline asm\n");
	}

	static void EmitMSInlineAsmStr(const char AsmStr, const MachineInstr MI,
	MachineModuleInfo *MMI, int InlineAsmVariant,
	AsmPrinter *AP, unsigned LocCookie,
	raw_ostream &OS) {
	// Switch to the inline assembly variant.
	OS << "\t.intel_syntax\n\t";

	const char *LastEmitted = AsmStr; // One past the last character emitted.
	unsigned NumOperands = MI->getNumOperands();

	while (*LastEmitted) {
	switch (*LastEmitted) {
	default: {
	// Not a special case, emit the string section literally.
	const char *LiteralEnd = LastEmitted+1;
	while (LiteralEnd && LiteralEnd != '{' && *LiteralEnd != '\|' &&
	LiteralEnd != '}' && LiteralEnd != '$' && *LiteralEnd != '\n')
	++LiteralEnd;

	OS.write(LastEmitted, LiteralEnd-LastEmitted);
	LastEmitted = LiteralEnd;
	break;
	}
	case '\n':
	++LastEmitted; // Consume newline character.
	OS << '\n'; // Indent code with newline.
	break;
	case '$': {
	++LastEmitted; // Consume '$' character.
	bool Done = true;

	// Handle escapes.
	switch (*LastEmitted) {
	default: Done = false; break;
	case '$':
	++LastEmitted; // Consume second '$' character.
	break;
	}
	if (Done) break;

	const char *IDStart = LastEmitted;
	const char *IDEnd = IDStart;
	while (IDEnd >= '0' && IDEnd <= '9') ++IDEnd;

	unsigned Val;
	if (StringRef(IDStart, IDEnd-IDStart).getAsInteger(10, Val))
	report_fatal_error("Bad $ operand number in inline asm string: '" +
	Twine(AsmStr) + "'");
	LastEmitted = IDEnd;

	if (Val >= NumOperands-1)
	report_fatal_error("Invalid $ operand number in inline asm string: '" +
	Twine(AsmStr) + "'");

	// Okay, we finally have a value number. Ask the target to print this
	// operand!
	unsigned OpNo = InlineAsm::MIOp_FirstOperand;

	bool Error = false;

	// Scan to find the machine operand number for the operand.
	for (; Val; --Val) {
	if (OpNo >= MI->getNumOperands()) break;
	unsigned OpFlags = MI->getOperand(OpNo).getImm();
	OpNo += InlineAsm::getNumOperandRegisters(OpFlags) + 1;
	}

	// We may have a location metadata attached to the end of the
	// instruction, and at no point should see metadata at any
	// other point while processing. It's an error if so.
	if (OpNo >= MI->getNumOperands() \|\|
	MI->getOperand(OpNo).isMetadata()) {
	Error = true;
	} else {
	unsigned OpFlags = MI->getOperand(OpNo).getImm();
	++OpNo; // Skip over the ID number.

	if (InlineAsm::isMemKind(OpFlags)) {
	Error = AP->PrintAsmMemoryOperand(MI, OpNo, InlineAsmVariant,
	/Modifier/ 0, OS);
	} else {
	Error = AP->PrintAsmOperand(MI, OpNo, InlineAsmVariant,
	/Modifier/ 0, OS);
	}
	}
	if (Error) {
	std::string msg;
	raw_string_ostream Msg(msg);
	Msg << "invalid operand in inline asm: '" << AsmStr << "'";
	MMI->getModule()->getContext().emitError(LocCookie, Msg.str());
	}
	break;
	}
	}
	}
	OS << "\n\t.att_syntax\n" << (char)0; // null terminate string.
	}

	static void EmitGCCInlineAsmStr(const char AsmStr, const MachineInstr MI,
	MachineModuleInfo *MMI, int InlineAsmVariant,
	int AsmPrinterVariant, AsmPrinter *AP,
	unsigned LocCookie, raw_ostream &OS) {
	int CurVariant = -1; // The number of the {.\|.\|.} region we are in.
	const char *LastEmitted = AsmStr; // One past the last character emitted.
	unsigned NumOperands = MI->getNumOperands();

	OS << '\t';

	while (*LastEmitted) {
	switch (*LastEmitted) {
	default: {
	// Not a special case, emit the string section literally.
	const char *LiteralEnd = LastEmitted+1;
	while (LiteralEnd && LiteralEnd != '{' && *LiteralEnd != '\|' &&
	LiteralEnd != '}' && LiteralEnd != '$' && *LiteralEnd != '\n')
	++LiteralEnd;
	if (CurVariant == -1 \|\| CurVariant == AsmPrinterVariant)
	OS.write(LastEmitted, LiteralEnd-LastEmitted);
	LastEmitted = LiteralEnd;
	break;
	}
	case '\n':
	++LastEmitted; // Consume newline character.
	OS << '\n'; // Indent code with newline.
	break;
	case '$': {
	++LastEmitted; // Consume '$' character.
	bool Done = true;

	// Handle escapes.
	switch (*LastEmitted) {
	default: Done = false; break;
	case '$': // $$ -> $
	if (CurVariant == -1 \|\| CurVariant == AsmPrinterVariant)
	OS << '$';
	++LastEmitted; // Consume second '$' character.
	break;
	case '(': // $( -> same as GCC's { character.
	++LastEmitted; // Consume '(' character.
	if (CurVariant != -1)
	report_fatal_error("Nested variants found in inline asm string: '" +
	Twine(AsmStr) + "'");
	CurVariant = 0; // We're in the first variant now.
	break;
	case '\|':
	++LastEmitted; // consume '\|' character.
	if (CurVariant == -1)
	OS << '\|'; // this is gcc's behavior for \| outside a variant
	else
	++CurVariant; // We're in the next variant.
	break;
	case ')': // $) -> same as GCC's } char.
	++LastEmitted; // consume ')' character.
	if (CurVariant == -1)
	OS << '}'; // this is gcc's behavior for } outside a variant
	else
	CurVariant = -1;
	break;
	}
	if (Done) break;

	bool HasCurlyBraces = false;
	if (*LastEmitted == '{') { // ${variable}
	++LastEmitted; // Consume '{' character.
	HasCurlyBraces = true;
	}

	// If we have ${:foo}, then this is not a real operand reference, it is a
	// "magic" string reference, just like in .td files. Arrange to call
	// PrintSpecial.
	if (HasCurlyBraces && *LastEmitted == ':') {
	++LastEmitted;
	const char *StrStart = LastEmitted;
	const char *StrEnd = strchr(StrStart, '}');
	if (StrEnd == 0)
	report_fatal_error("Unterminated ${:foo} operand in inline asm"
	" string: '" + Twine(AsmStr) + "'");

	std::string Val(StrStart, StrEnd);
	AP->PrintSpecial(MI, OS, Val.c_str());
	LastEmitted = StrEnd+1;
	break;
	}

	const char *IDStart = LastEmitted;
	const char *IDEnd = IDStart;
	while (IDEnd >= '0' && IDEnd <= '9') ++IDEnd;

	unsigned Val;
	if (StringRef(IDStart, IDEnd-IDStart).getAsInteger(10, Val))
	report_fatal_error("Bad $ operand number in inline asm string: '" +
	Twine(AsmStr) + "'");
	LastEmitted = IDEnd;

	char Modifier[2] = { 0, 0 };

	if (HasCurlyBraces) {
	// If we have curly braces, check for a modifier character. This
	// supports syntax like ${0:u}, which correspond to "%u0" in GCC asm.
	if (*LastEmitted == ':') {
	++LastEmitted; // Consume ':' character.
	if (*LastEmitted == 0)
	report_fatal_error("Bad ${:} expression in inline asm string: '" +
	Twine(AsmStr) + "'");

	Modifier[0] = *LastEmitted;
	++LastEmitted; // Consume modifier character.
	}

	if (*LastEmitted != '}')
	report_fatal_error("Bad ${} expression in inline asm string: '" +
	Twine(AsmStr) + "'");
	++LastEmitted; // Consume '}' character.
	}

	if (Val >= NumOperands-1)
	report_fatal_error("Invalid $ operand number in inline asm string: '" +
	Twine(AsmStr) + "'");

	// Okay, we finally have a value number. Ask the target to print this
	// operand!
	if (CurVariant == -1 \|\| CurVariant == AsmPrinterVariant) {
	unsigned OpNo = InlineAsm::MIOp_FirstOperand;

	bool Error = false;

	// Scan to find the machine operand number for the operand.
	for (; Val; --Val) {
	if (OpNo >= MI->getNumOperands()) break;
	unsigned OpFlags = MI->getOperand(OpNo).getImm();
	OpNo += InlineAsm::getNumOperandRegisters(OpFlags) + 1;
	}

	// We may have a location metadata attached to the end of the
	// instruction, and at no point should see metadata at any
	// other point while processing. It's an error if so.
	if (OpNo >= MI->getNumOperands() \|\|
	MI->getOperand(OpNo).isMetadata()) {
	Error = true;
	} else {
	unsigned OpFlags = MI->getOperand(OpNo).getImm();
	++OpNo; // Skip over the ID number.

	if (Modifier[0] == 'l') // labels are target independent
	// FIXME: What if the operand isn't an MBB, report error?
	OS << *MI->getOperand(OpNo).getMBB()->getSymbol();
	else {
	if (InlineAsm::isMemKind(OpFlags)) {
	Error = AP->PrintAsmMemoryOperand(MI, OpNo, InlineAsmVariant,
	Modifier[0] ? Modifier : 0,
	OS);
	} else {
	Error = AP->PrintAsmOperand(MI, OpNo, InlineAsmVariant,
	Modifier[0] ? Modifier : 0, OS);
	}
	}
	}
	if (Error) {
	std::string msg;
	raw_string_ostream Msg(msg);
	Msg << "invalid operand in inline asm: '" << AsmStr << "'";
	MMI->getModule()->getContext().emitError(LocCookie, Msg.str());
	}
	}
	break;
	}
	}
	}
	OS << '\n' << (char)0; // null terminate string.
	}

	/// EmitInlineAsm - This method formats and emits the specified machine
	/// instruction that is an inline asm.
	void AsmPrinter::EmitInlineAsm(const MachineInstr *MI) const {
	assert(MI->isInlineAsm() && "printInlineAsm only works on inline asms");

	// Count the number of register definitions to find the asm string.
	unsigned NumDefs = 0;
	for (; MI->getOperand(NumDefs).isReg() && MI->getOperand(NumDefs).isDef();
	++NumDefs)
	assert(NumDefs != MI->getNumOperands()-2 && "No asm string?");

	assert(MI->getOperand(NumDefs).isSymbol() && "No asm string?");

	// Disassemble the AsmStr, printing out the literal pieces, the operands, etc.
	const char *AsmStr = MI->getOperand(NumDefs).getSymbolName();

	// If this asmstr is empty, just print the #APP/#NOAPP markers.
	// These are useful to see where empty asm's wound up.
	if (AsmStr[0] == 0) {
	// Don't emit the comments if writing to a .o file.
	if (!OutStreamer.hasRawTextSupport()) return;

	OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
	MAI->getInlineAsmStart());
	OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
	MAI->getInlineAsmEnd());
	return;
	}

	// Emit the #APP start marker. This has to happen even if verbose-asm isn't
	// enabled, so we use EmitRawText.
	if (OutStreamer.hasRawTextSupport())
	OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
	MAI->getInlineAsmStart());

	// Get the !srcloc metadata node if we have it, and decode the loc cookie from
	// it.
	unsigned LocCookie = 0;
	const MDNode *LocMD = 0;
	for (unsigned i = MI->getNumOperands(); i != 0; --i) {
	if (MI->getOperand(i-1).isMetadata() &&
	(LocMD = MI->getOperand(i-1).getMetadata()) &&
	LocMD->getNumOperands() != 0) {
	if (const ConstantInt *CI = dyn_cast<ConstantInt>(LocMD->getOperand(0))) {
	LocCookie = CI->getZExtValue();
	break;
	}
	}
	}

	// Emit the inline asm to a temporary string so we can emit it through
	// EmitInlineAsm.
	SmallString<256> StringData;
	raw_svector_ostream OS(StringData);

	// The variant of the current asmprinter.
	int AsmPrinterVariant = MAI->getAssemblerDialect();
	InlineAsm::AsmDialect InlineAsmVariant = MI->getInlineAsmDialect();
	AsmPrinter AP = const_cast<AsmPrinter>(this);
	if (InlineAsmVariant == InlineAsm::AD_ATT)
	EmitGCCInlineAsmStr(AsmStr, MI, MMI, InlineAsmVariant, AsmPrinterVariant,
	AP, LocCookie, OS);
	else
	EmitMSInlineAsmStr(AsmStr, MI, MMI, InlineAsmVariant, AP, LocCookie, OS);

	EmitInlineAsm(OS.str(), LocMD, MI->getInlineAsmDialect());

	// Emit the #NOAPP end marker. This has to happen even if verbose-asm isn't
	// enabled, so we use EmitRawText.
	if (OutStreamer.hasRawTextSupport())
	OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
	MAI->getInlineAsmEnd());
	}


	/// PrintSpecial - Print information related to the specified machine instr
	/// that is independent of the operand, and may be independent of the instr
	/// itself. This can be useful for portably encoding the comment character
	/// or other bits of target-specific knowledge into the asmstrings. The
	/// syntax used is ${:comment}. Targets can override this to add support
	/// for their own strange codes.
	void AsmPrinter::PrintSpecial(const MachineInstr *MI, raw_ostream &OS,
	const char *Code) const {
	if (!strcmp(Code, "private")) {
	OS << MAI->getPrivateGlobalPrefix();
	} else if (!strcmp(Code, "comment")) {
	OS << MAI->getCommentString();
	} else if (!strcmp(Code, "uid")) {
	// Comparing the address of MI isn't sufficient, because machineinstrs may
	// be allocated to the same address across functions.

	// If this is a new LastFn instruction, bump the counter.
	if (LastMI != MI \|\| LastFn != getFunctionNumber()) {
	++Counter;
	LastMI = MI;
	LastFn = getFunctionNumber();
	}
	OS << Counter;
	} else {
	std::string msg;
	raw_string_ostream Msg(msg);
	Msg << "Unknown special formatter '" << Code
	<< "' for machine instr: " << *MI;
	report_fatal_error(Msg.str());
	}
	}

	/// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
	/// instruction, using the specified assembler variant. Targets should
	/// override this to format as appropriate.
	bool AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
	unsigned AsmVariant, const char *ExtraCode,
	raw_ostream &O) {
	// Does this asm operand have a single letter operand modifier?
	if (ExtraCode && ExtraCode[0]) {
	if (ExtraCode[1] != 0) return true; // Unknown modifier.

	const MachineOperand &MO = MI->getOperand(OpNo);
	switch (ExtraCode[0]) {
	default:
	return true; // Unknown modifier.
	case 'c': // Substitute immediate value without immediate syntax
	if (MO.getType() != MachineOperand::MO_Immediate)
	return true;
	O << MO.getImm();
	return false;
	case 'n': // Negate the immediate constant.
	if (MO.getType() != MachineOperand::MO_Immediate)
	return true;
	O << -MO.getImm();
	return false;
	}
	}
	return true;
	}

	bool AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
	unsigned AsmVariant,
	const char *ExtraCode, raw_ostream &O) {
	// Target doesn't support this yet!
	return true;
	}