tools/llvm-cxxfilt/llvm-cxxfilt.cpp

   1 //===-- llvm-c++filt.cpp --------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "llvm/ADT/StringExtras.h"
  10 #include "llvm/Demangle/Demangle.h"
  11 #include "llvm/Support/CommandLine.h"
  12 #include "llvm/Support/InitLLVM.h"
  13 #include "llvm/Support/raw_ostream.h"
  14 #include <cstdlib>
  15 #include <iostream>
  16
  17 using namespace llvm;
  18
  19 enum Style {
  20   Auto,  ///< auto-detect mangling
  21   GNU,   ///< GNU
  22   Lucid, ///< Lucid compiler (lcc)
  23   ARM,
  24   HP,    ///< HP compiler (xCC)
  25   EDG,   ///< EDG compiler
  26   GNUv3, ///< GNU C++ v3 ABI
  27   Java,  ///< Java (gcj)
  28   GNAT   ///< ADA compiler (gnat)
  29 };
  30 static cl::opt<Style>
  31     Format("format", cl::desc("decoration style"),
  32            cl::values(clEnumValN(Auto, "auto", "auto-detect style"),
  33                       clEnumValN(GNU, "gnu", "GNU (itanium) style")),
  34            cl::init(Auto));
  35 static cl::alias FormatShort("s", cl::desc("alias for --format"),
  36                              cl::aliasopt(Format));
  37
  38 static cl::opt<bool> StripUnderscore("strip-underscore",
  39                                      cl::desc("strip the leading underscore"),
  40                                      cl::init(false));
  41 static cl::alias StripUnderscoreShort("_",
  42                                       cl::desc("alias for --strip-underscore"),
  43                                       cl::aliasopt(StripUnderscore));
  44
  45 static cl::opt<bool>
  46     Types("types",
  47           cl::desc("attempt to demangle types as well as function names"),
  48           cl::init(false));
  49 static cl::alias TypesShort("t", cl::desc("alias for --types"),
  50                             cl::aliasopt(Types));
  51
  52 static cl::list<std::string>
  53 Decorated(cl::Positional, cl::desc("<mangled>"), cl::ZeroOrMore);
  54
  55 static cl::extrahelp
  56     HelpResponse("\nPass @FILE as argument to read options from FILE.\n");
  57
  58 static std::string demangle(llvm::raw_ostream &OS, const std::string &Mangled) {
  59   int Status;
  60
  61   const char *DecoratedStr = Mangled.c_str();
  62   if (StripUnderscore)
  63     if (DecoratedStr[0] == '_')
  64       ++DecoratedStr;
  65   size_t DecoratedLength = strlen(DecoratedStr);
  66
  67   char *Undecorated = nullptr;
  68
  69   if (Types ||
  70       ((DecoratedLength >= 2 && strncmp(DecoratedStr, "_Z", 2) == 0) ||
  71        (DecoratedLength >= 4 && strncmp(DecoratedStr, "___Z", 4) == 0)))
  72     Undecorated = itaniumDemangle(DecoratedStr, nullptr, nullptr, &Status);
  73
  74   if (!Undecorated &&
  75       (DecoratedLength > 6 && strncmp(DecoratedStr, "__imp_", 6) == 0)) {
  76     OS << "import thunk for ";
  77     Undecorated = itaniumDemangle(DecoratedStr + 6, nullptr, nullptr, &Status);
  78   }
  79
  80   std::string Result(Undecorated ? Undecorated : Mangled);
  81   free(Undecorated);
  82   return Result;
  83 }
  84
  85 // Split 'Source' on any character that fails to pass 'IsLegalChar'.  The
  86 // returned vector consists of pairs where 'first' is the delimited word, and
  87 // 'second' are the delimiters following that word.
  88 static void SplitStringDelims(
  89     StringRef Source,
  90     SmallVectorImpl<std::pair<StringRef, StringRef>> &OutFragments,
  91     function_ref<bool(char)> IsLegalChar) {
  92   // The beginning of the input string.
  93   const auto Head = Source.begin();
  94
  95   // Obtain any leading delimiters.
  96   auto Start = std::find_if(Head, Source.end(), IsLegalChar);
  97   if (Start != Head)
  98     OutFragments.push_back({"", Source.slice(0, Start - Head)});
  99
 100   // Capture each word and the delimiters following that word.
 101   while (Start != Source.end()) {
 102     Start = std::find_if(Start, Source.end(), IsLegalChar);
 103     auto End = std::find_if_not(Start, Source.end(), IsLegalChar);
 104     auto DEnd = std::find_if(End, Source.end(), IsLegalChar);
 105     OutFragments.push_back({Source.slice(Start - Head, End - Head),
 106                             Source.slice(End - Head, DEnd - Head)});
 107     Start = DEnd;
 108   }
 109 }
 110
 111 // This returns true if 'C' is a character that can show up in an
 112 // Itanium-mangled string.
 113 static bool IsLegalItaniumChar(char C) {
 114   // Itanium CXX ABI [External Names]p5.1.1:
 115   // '$' and '.' in mangled names are reserved for private implementations.
 116   return isalnum(C) || C == '.' || C == '$' || C == '_';
 117 }
 118
 119 // If 'Split' is true, then 'Mangled' is broken into individual words and each
 120 // word is demangled.  Otherwise, the entire string is treated as a single
 121 // mangled item.  The result is output to 'OS'.
 122 static void demangleLine(llvm::raw_ostream &OS, StringRef Mangled, bool Split) {
 123   std::string Result;
 124   if (Split) {
 125     SmallVector<std::pair<StringRef, StringRef>, 16> Words;
 126     SplitStringDelims(Mangled, Words, IsLegalItaniumChar);
 127     for (const auto &Word : Words)
 128       Result += demangle(OS, Word.first) + Word.second.str();
 129   } else
 130     Result = demangle(OS, Mangled);
 131   OS << Result << '\n';
 132   OS.flush();
 133 }
 134
 135 int main(int argc, char **argv) {
 136   InitLLVM X(argc, argv);
 137
 138   cl::ParseCommandLineOptions(argc, argv, "llvm symbol undecoration tool\n");
 139
 140   if (Decorated.empty())
 141     for (std::string Mangled; std::getline(std::cin, Mangled);)
 142       demangleLine(llvm::outs(), Mangled, true);
 143   else
 144     for (const auto &Symbol : Decorated)
 145       demangleLine(llvm::outs(), Symbol, false);
 146
 147   return EXIT_SUCCESS;
 148 }