lib/VMCore/Mangler.cpp

   1 //===-- Mangler.cpp - Self-contained c/asm llvm name mangler --------------===//
   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 // Unified name mangler for CWriter and assembly backends.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/Support/Mangler.h"
  15 #include "llvm/Function.h"
  16 #include "llvm/ADT/STLExtras.h"
  17 #include "llvm/ADT/StringExtras.h"
  18 #include "llvm/ADT/StringMap.h"
  19 #include "llvm/ADT/SmallVector.h"
  20 #include "llvm/Support/raw_ostream.h"
  21 using namespace llvm;
  22
  23 static char HexDigit(int V) {
  24   return V < 10 ? V+'0' : V+'A'-10;
  25 }
  26
  27 static std::string MangleLetter(unsigned char C) {
  28   char Result[] = { '_', HexDigit(C >> 4), HexDigit(C & 15), '_', 0 };
  29   return Result;
  30 }
  31
  32 /// makeNameProper - We don't want identifier names non-C-identifier characters
  33 /// in them, so mangle them as appropriate.
  34 ///
  35 std::string Mangler::makeNameProper(const std::string &X,
  36                                     ManglerPrefixTy PrefixTy) {
  37   assert(!X.empty() && "Cannot mangle empty strings");
  38
  39   if (!UseQuotes) {
  40     std::string Result;
  41
  42     // If X does not start with (char)1, add the prefix.
  43     bool NeedPrefix = true;
  44     std::string::const_iterator I = X.begin();
  45     if (*I == 1) {
  46       NeedPrefix = false;
  47       ++I;  // Skip over the marker.
  48     }
  49
  50     // Mangle the first letter specially, don't allow numbers.
  51     if (*I >= '0' && *I <= '9')
  52       Result += MangleLetter(*I++);
  53
  54     for (std::string::const_iterator E = X.end(); I != E; ++I) {
  55       if (!isCharAcceptable(*I))
  56         Result += MangleLetter(*I);
  57       else
  58         Result += *I;
  59     }
  60
  61     if (NeedPrefix) {
  62       Result = Prefix + Result;
  63
  64       if (PrefixTy == Mangler::Private)
  65         Result = PrivatePrefix + Result;
  66       else if (PrefixTy == Mangler::LinkerPrivate)
  67         Result = LinkerPrivatePrefix + Result;
  68     }
  69
  70     return Result;
  71   }
  72
  73   bool NeedPrefix = true;
  74   bool NeedQuotes = false;
  75   std::string Result;
  76   std::string::const_iterator I = X.begin();
  77   if (*I == 1) {
  78     NeedPrefix = false;
  79     ++I;  // Skip over the marker.
  80   }
  81
  82   // If the first character is a number, we need quotes.
  83   if (*I >= '0' && *I <= '9')
  84     NeedQuotes = true;
  85
  86   // Do an initial scan of the string, checking to see if we need quotes or
  87   // to escape a '"' or not.
  88   if (!NeedQuotes)
  89     for (std::string::const_iterator E = X.end(); I != E; ++I)
  90       if (!isCharAcceptable(*I)) {
  91         NeedQuotes = true;
  92         break;
  93       }
  94
  95   // In the common case, we don't need quotes.  Handle this quickly.
  96   if (!NeedQuotes) {
  97     if (!NeedPrefix)
  98       return X.substr(1);   // Strip off the \001.
  99
 100     Result = Prefix + X;
 101
 102     if (PrefixTy == Mangler::Private)
 103       Result = PrivatePrefix + Result;
 104     else if (PrefixTy == Mangler::LinkerPrivate)
 105       Result = LinkerPrivatePrefix + Result;
 106
 107     return Result;
 108   }
 109
 110   if (NeedPrefix)
 111     Result = X.substr(0, I-X.begin());
 112
 113   // Otherwise, construct the string the expensive way.
 114   for (std::string::const_iterator E = X.end(); I != E; ++I) {
 115     if (*I == '"')
 116       Result += "_QQ_";
 117     else if (*I == '\n')
 118       Result += "_NL_";
 119     else
 120       Result += *I;
 121   }
 122
 123   if (NeedPrefix) {
 124     Result = Prefix + Result;
 125
 126     if (PrefixTy == Mangler::Private)
 127       Result = PrivatePrefix + Result;
 128     else if (PrefixTy == Mangler::LinkerPrivate)
 129       Result = LinkerPrivatePrefix + Result;
 130   }
 131
 132   Result = '"' + Result + '"';
 133   return Result;
 134 }
 135
 136 /// getMangledName - Returns the mangled name of V, an LLVM Value,
 137 /// in the current module.  If 'Suffix' is specified, the name ends with the
 138 /// specified suffix.  If 'ForcePrivate' is specified, the label is specified
 139 /// to have a private label prefix.
 140 ///
 141 std::string Mangler::getMangledName(const GlobalValue *GV, const char *Suffix,
 142                                     bool ForcePrivate) {
 143   assert((!isa<Function>(GV) || !cast<Function>(GV)->isIntrinsic()) &&
 144          "Intrinsic functions cannot be mangled by Mangler");
 145
 146   ManglerPrefixTy PrefixTy =
 147     (GV->hasPrivateLinkage() || ForcePrivate) ? Mangler::Private :
 148       GV->hasLinkerPrivateLinkage() ? Mangler::LinkerPrivate : Mangler::Default;
 149
 150   if (GV->hasName())
 151     return makeNameProper(GV->getNameStr() + Suffix, PrefixTy);
 152
 153   // Get the ID for the global, assigning a new one if we haven't got one
 154   // already.
 155   unsigned &ID = AnonGlobalIDs[GV];
 156   if (ID == 0) ID = NextAnonGlobalID++;
 157
 158   // Must mangle the global into a unique ID.
 159   return makeNameProper("__unnamed_" + utostr(ID) + Suffix, PrefixTy);
 160 }
 161
 162
 163 /// getNameWithPrefix - Fill OutName with the name of the appropriate prefix
 164 /// and the specified global variable's name.  If the global variable doesn't
 165 /// have a name, this fills in a unique name for the global.
 166 void Mangler::getNameWithPrefix(SmallVectorImpl<char> &OutName,
 167                                 const GlobalValue *GV,
 168                                 bool isImplicitlyPrivate) {
 169
 170   // If the global is anonymous or not led with \1, then add the appropriate
 171   // prefix.
 172   if (!GV->hasName() || GV->getName()[0] != '\1') {
 173     if (GV->hasPrivateLinkage() || isImplicitlyPrivate)
 174       OutName.append(PrivatePrefix, PrivatePrefix+strlen(PrivatePrefix));
 175     else if (GV->hasLinkerPrivateLinkage())
 176       OutName.append(LinkerPrivatePrefix,
 177                      LinkerPrivatePrefix+strlen(LinkerPrivatePrefix));;
 178     OutName.append(Prefix, Prefix+strlen(Prefix));
 179   }
 180
 181   // If the global has a name, just append it now.
 182   if (GV->hasName()) {
 183     StringRef Name = GV->getName();
 184
 185     // Strip off the prefix marker if present.
 186     if (Name[0] != '\1')
 187       OutName.append(Name.begin(), Name.end());
 188     else
 189       OutName.append(Name.begin()+1, Name.end());
 190     return;
 191   }
 192
 193   // If the global variable doesn't have a name, return a unique name for the
 194   // global based on a numbering.
 195
 196   // Get the ID for the global, assigning a new one if we haven't got one
 197   // already.
 198   unsigned &ID = AnonGlobalIDs[GV];
 199   if (ID == 0) ID = NextAnonGlobalID++;
 200
 201   // Must mangle the global into a unique ID.
 202   raw_svector_ostream(OutName) << "__unnamed_" << ID;
 203 }
 204
 205
 206 Mangler::Mangler(Module &M, const char *prefix, const char *privatePrefix,
 207                  const char *linkerPrivatePrefix)
 208   : Prefix(prefix), PrivatePrefix(privatePrefix),
 209     LinkerPrivatePrefix(linkerPrivatePrefix), UseQuotes(false),
 210     NextAnonGlobalID(1) {
 211   std::fill(AcceptableChars, array_endof(AcceptableChars), 0);
 212
 213   // Letters and numbers are acceptable.
 214   for (unsigned char X = 'a'; X <= 'z'; ++X)
 215     markCharAcceptable(X);
 216   for (unsigned char X = 'A'; X <= 'Z'; ++X)
 217     markCharAcceptable(X);
 218   for (unsigned char X = '0'; X <= '9'; ++X)
 219     markCharAcceptable(X);
 220
 221   // These chars are acceptable.
 222   markCharAcceptable('_');
 223   markCharAcceptable('$');
 224   markCharAcceptable('.');
 225   markCharAcceptable('@');
 226 }