llvm/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/ADT/Triple.h"
  11 #include "llvm/Demangle/Demangle.h"
  12 #include "llvm/Option/Arg.h"
  13 #include "llvm/Option/ArgList.h"
  14 #include "llvm/Option/Option.h"
  15 #include "llvm/Support/CommandLine.h"
  16 #include "llvm/Support/Host.h"
  17 #include "llvm/Support/InitLLVM.h"
  18 #include "llvm/Support/WithColor.h"
  19 #include "llvm/Support/raw_ostream.h"
  20 #include <cstdlib>
  21 #include <iostream>
  22
  23 using namespace llvm;
  24
  25 namespace {
  26 enum ID {
  27   OPT_INVALID = 0, // This is not an option ID.
  28 #define OPTION(PREFIX, NAME, ID, KIND, GROUP, ALIAS, ALIASARGS, FLAGS, PARAM,  \
  29                HELPTEXT, METAVAR, VALUES)                                      \
  30   OPT_##ID,
  31 #include "Opts.inc"
  32 #undef OPTION
  33 };
  34
  35 #define PREFIX(NAME, VALUE) const char *const NAME[] = VALUE;
  36 #include "Opts.inc"
  37 #undef PREFIX
  38
  39 const opt::OptTable::Info InfoTable[] = {
  40 #define OPTION(PREFIX, NAME, ID, KIND, GROUP, ALIAS, ALIASARGS, FLAGS, PARAM,  \
  41                HELPTEXT, METAVAR, VALUES)                                      \
  42   {                                                                            \
  43       PREFIX,      NAME,      HELPTEXT,                                        \
  44       METAVAR,     OPT_##ID,  opt::Option::KIND##Class,                        \
  45       PARAM,       FLAGS,     OPT_##GROUP,                                     \
  46       OPT_##ALIAS, ALIASARGS, VALUES},
  47 #include "Opts.inc"
  48 #undef OPTION
  49 };
  50
  51 class CxxfiltOptTable : public opt::OptTable {
  52 public:
  53   CxxfiltOptTable() : OptTable(InfoTable) { setGroupedShortOptions(true); }
  54 };
  55 } // namespace
  56
  57 static bool StripUnderscore;
  58 static bool Types;
  59
  60 static StringRef ToolName;
  61
  62 static void error(const Twine &Message) {
  63   WithColor::error(errs(), ToolName) << Message << '\n';
  64   exit(1);
  65 }
  66
  67 static std::string demangle(const std::string &Mangled) {
  68   const char *DecoratedStr = Mangled.c_str();
  69   if (StripUnderscore)
  70     if (DecoratedStr[0] == '_')
  71       ++DecoratedStr;
  72
  73   std::string Result;
  74   if (nonMicrosoftDemangle(DecoratedStr, Result))
  75     return Result;
  76
  77   std::string Prefix;
  78   char *Undecorated = nullptr;
  79
  80   if (Types)
  81     Undecorated = itaniumDemangle(DecoratedStr, nullptr, nullptr, nullptr);
  82
  83   if (!Undecorated && strncmp(DecoratedStr, "__imp_", 6) == 0) {
  84     Prefix = "import thunk for ";
  85     Undecorated = itaniumDemangle(DecoratedStr + 6, nullptr, nullptr, nullptr);
  86   }
  87
  88   Result = Undecorated ? Prefix + Undecorated : Mangled;
  89   free(Undecorated);
  90   return Result;
  91 }
  92
  93 // Split 'Source' on any character that fails to pass 'IsLegalChar'.  The
  94 // returned vector consists of pairs where 'first' is the delimited word, and
  95 // 'second' are the delimiters following that word.
  96 static void SplitStringDelims(
  97     StringRef Source,
  98     SmallVectorImpl<std::pair<StringRef, StringRef>> &OutFragments,
  99     function_ref<bool(char)> IsLegalChar) {
 100   // The beginning of the input string.
 101   const auto Head = Source.begin();
 102
 103   // Obtain any leading delimiters.
 104   auto Start = std::find_if(Head, Source.end(), IsLegalChar);
 105   if (Start != Head)
 106     OutFragments.push_back({"", Source.slice(0, Start - Head)});
 107
 108   // Capture each word and the delimiters following that word.
 109   while (Start != Source.end()) {
 110     Start = std::find_if(Start, Source.end(), IsLegalChar);
 111     auto End = std::find_if_not(Start, Source.end(), IsLegalChar);
 112     auto DEnd = std::find_if(End, Source.end(), IsLegalChar);
 113     OutFragments.push_back({Source.slice(Start - Head, End - Head),
 114                             Source.slice(End - Head, DEnd - Head)});
 115     Start = DEnd;
 116   }
 117 }
 118
 119 // This returns true if 'C' is a character that can show up in an
 120 // Itanium-mangled string.
 121 static bool IsLegalItaniumChar(char C) {
 122   // Itanium CXX ABI [External Names]p5.1.1:
 123   // '$' and '.' in mangled names are reserved for private implementations.
 124   return isAlnum(C) || C == '.' || C == '$' || C == '_';
 125 }
 126
 127 // If 'Split' is true, then 'Mangled' is broken into individual words and each
 128 // word is demangled.  Otherwise, the entire string is treated as a single
 129 // mangled item.  The result is output to 'OS'.
 130 static void demangleLine(llvm::raw_ostream &OS, StringRef Mangled, bool Split) {
 131   std::string Result;
 132   if (Split) {
 133     SmallVector<std::pair<StringRef, StringRef>, 16> Words;
 134     SplitStringDelims(Mangled, Words, IsLegalItaniumChar);
 135     for (const auto &Word : Words)
 136       Result += ::demangle(std::string(Word.first)) + Word.second.str();
 137   } else
 138     Result = ::demangle(std::string(Mangled));
 139   OS << Result << '\n';
 140   OS.flush();
 141 }
 142
 143 int llvm_cxxfilt_main(int argc, char **argv) {
 144   InitLLVM X(argc, argv);
 145   BumpPtrAllocator A;
 146   StringSaver Saver(A);
 147   CxxfiltOptTable Tbl;
 148   ToolName = argv[0];
 149   opt::InputArgList Args = Tbl.parseArgs(argc, argv, OPT_UNKNOWN, Saver,
 150                                          [&](StringRef Msg) { error(Msg); });
 151   if (Args.hasArg(OPT_help)) {
 152     Tbl.printHelp(outs(),
 153                   (Twine(ToolName) + " [options] <mangled>").str().c_str(),
 154                   "LLVM symbol undecoration tool");
 155     // TODO Replace this with OptTable API once it adds extrahelp support.
 156     outs() << "\nPass @FILE as argument to read options from FILE.\n";
 157     return 0;
 158   }
 159   if (Args.hasArg(OPT_version)) {
 160     outs() << ToolName << '\n';
 161     cl::PrintVersionMessage();
 162     return 0;
 163   }
 164
 165   // The default value depends on the default triple. Mach-O has symbols
 166   // prefixed with "_", so strip by default.
 167   if (opt::Arg *A =
 168           Args.getLastArg(OPT_strip_underscore, OPT_no_strip_underscore))
 169     StripUnderscore = A->getOption().matches(OPT_strip_underscore);
 170   else
 171     StripUnderscore = Triple(sys::getProcessTriple()).isOSBinFormatMachO();
 172
 173   Types = Args.hasArg(OPT_types);
 174
 175   std::vector<std::string> Decorated = Args.getAllArgValues(OPT_INPUT);
 176   if (Decorated.empty())
 177     for (std::string Mangled; std::getline(std::cin, Mangled);)
 178       demangleLine(llvm::outs(), Mangled, true);
 179   else
 180     for (const auto &Symbol : Decorated)
 181       demangleLine(llvm::outs(), Symbol, false);
 182
 183   return EXIT_SUCCESS;
 184 }