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      1 //===-- ARMAsmLexer.cpp - Tokenize ARM assembly to AsmTokens --------------===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 
     10 #include "MCTargetDesc/ARMBaseInfo.h"
     11 
     12 #include "llvm/MC/MCAsmInfo.h"
     13 #include "llvm/MC/MCParser/MCAsmLexer.h"
     14 #include "llvm/MC/MCParser/MCParsedAsmOperand.h"
     15 #include "llvm/MC/MCRegisterInfo.h"
     16 #include "llvm/MC/MCTargetAsmLexer.h"
     17 
     18 #include "llvm/Support/TargetRegistry.h"
     19 
     20 #include "llvm/ADT/OwningPtr.h"
     21 #include "llvm/ADT/SmallVector.h"
     22 #include "llvm/ADT/StringExtras.h"
     23 #include "llvm/ADT/StringSwitch.h"
     24 
     25 #include <string>
     26 #include <map>
     27 
     28 using namespace llvm;
     29 
     30 namespace {
     31 
     32 class ARMBaseAsmLexer : public MCTargetAsmLexer {
     33   const MCAsmInfo &AsmInfo;
     34 
     35   const AsmToken &lexDefinite() {
     36     return getLexer()->Lex();
     37   }
     38 
     39   AsmToken LexTokenUAL();
     40 protected:
     41   typedef std::map <std::string, unsigned> rmap_ty;
     42 
     43   rmap_ty RegisterMap;
     44 
     45   void InitRegisterMap(const MCRegisterInfo *info) {
     46     unsigned numRegs = info->getNumRegs();
     47 
     48     for (unsigned i = 0; i < numRegs; ++i) {
     49       const char *regName = info->getName(i);
     50       if (regName)
     51         RegisterMap[regName] = i;
     52     }
     53   }
     54 
     55   unsigned MatchRegisterName(StringRef Name) {
     56     rmap_ty::iterator iter = RegisterMap.find(Name.str());
     57     if (iter != RegisterMap.end())
     58       return iter->second;
     59     else
     60       return 0;
     61   }
     62 
     63   AsmToken LexToken() {
     64     if (!Lexer) {
     65       SetError(SMLoc(), "No MCAsmLexer installed");
     66       return AsmToken(AsmToken::Error, "", 0);
     67     }
     68 
     69     switch (AsmInfo.getAssemblerDialect()) {
     70     default:
     71       SetError(SMLoc(), "Unhandled dialect");
     72       return AsmToken(AsmToken::Error, "", 0);
     73     case 0:
     74       return LexTokenUAL();
     75     }
     76   }
     77 public:
     78   ARMBaseAsmLexer(const Target &T, const MCAsmInfo &MAI)
     79     : MCTargetAsmLexer(T), AsmInfo(MAI) {
     80   }
     81 };
     82 
     83 class ARMAsmLexer : public ARMBaseAsmLexer {
     84 public:
     85   ARMAsmLexer(const Target &T, const MCRegisterInfo &MRI, const MCAsmInfo &MAI)
     86     : ARMBaseAsmLexer(T, MAI) {
     87     InitRegisterMap(&MRI);
     88   }
     89 };
     90 
     91 class ThumbAsmLexer : public ARMBaseAsmLexer {
     92 public:
     93   ThumbAsmLexer(const Target &T, const MCRegisterInfo &MRI,const MCAsmInfo &MAI)
     94     : ARMBaseAsmLexer(T, MAI) {
     95     InitRegisterMap(&MRI);
     96   }
     97 };
     98 
     99 } // end anonymous namespace
    100 
    101 AsmToken ARMBaseAsmLexer::LexTokenUAL() {
    102   const AsmToken &lexedToken = lexDefinite();
    103 
    104   switch (lexedToken.getKind()) {
    105   default: break;
    106   case AsmToken::Error:
    107     SetError(Lexer->getErrLoc(), Lexer->getErr());
    108     break;
    109   case AsmToken::Identifier: {
    110     std::string upperCase = lexedToken.getString().str();
    111     std::string lowerCase = LowercaseString(upperCase);
    112     StringRef lowerRef(lowerCase);
    113 
    114     unsigned regID = MatchRegisterName(lowerRef);
    115     // Check for register aliases.
    116     //   r13 -> sp
    117     //   r14 -> lr
    118     //   r15 -> pc
    119     //   ip  -> r12
    120     //   FIXME: Some assemblers support lots of others. Do we want them all?
    121     if (!regID) {
    122       regID = StringSwitch<unsigned>(lowerCase)
    123         .Case("r13", ARM::SP)
    124         .Case("r14", ARM::LR)
    125         .Case("r15", ARM::PC)
    126         .Case("ip", ARM::R12)
    127         .Default(0);
    128     }
    129 
    130     if (regID)
    131       return AsmToken(AsmToken::Register,
    132                       lexedToken.getString(),
    133                       static_cast<int64_t>(regID));
    134   }
    135   }
    136 
    137   return AsmToken(lexedToken);
    138 }
    139 
    140 extern "C" void LLVMInitializeARMAsmLexer() {
    141   RegisterMCAsmLexer<ARMAsmLexer> X(TheARMTarget);
    142   RegisterMCAsmLexer<ThumbAsmLexer> Y(TheThumbTarget);
    143 }
    144