xref: /llvm-project/llvm/tools/llvm-cxxfilt/llvm-cxxfilt.cpp (revision dd647e3e608ed0b2bac7c588d5859b80ef4a5976)
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/Demangle/StringViewExtras.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/LLVMDriver.h"
17 #include "llvm/Support/WithColor.h"
18 #include "llvm/Support/raw_ostream.h"
19 #include "llvm/TargetParser/Host.h"
20 #include "llvm/TargetParser/Triple.h"
21 #include <cstdlib>
22 #include <iostream>
23 
24 using namespace llvm;
25 
26 namespace {
27 enum ID {
28   OPT_INVALID = 0, // This is not an option ID.
29 #define OPTION(...) LLVM_MAKE_OPT_ID(__VA_ARGS__),
30 #include "Opts.inc"
31 #undef OPTION
32 };
33 
34 #define OPTTABLE_STR_TABLE_CODE
35 #include "Opts.inc"
36 #undef OPTTABLE_STR_TABLE_CODE
37 
38 #define OPTTABLE_PREFIXES_TABLE_CODE
39 #include "Opts.inc"
40 #undef OPTTABLE_PREFIXES_TABLE_CODE
41 
42 using namespace llvm::opt;
43 static constexpr opt::OptTable::Info InfoTable[] = {
44 #define OPTION(...) LLVM_CONSTRUCT_OPT_INFO(__VA_ARGS__),
45 #include "Opts.inc"
46 #undef OPTION
47 };
48 
49 class CxxfiltOptTable : public opt::GenericOptTable {
50 public:
51   CxxfiltOptTable()
52       : opt::GenericOptTable(OptionStrTable, OptionPrefixesTable, InfoTable) {
53     setGroupedShortOptions(true);
54   }
55 };
56 } // namespace
57 
58 static bool ParseParams;
59 static bool Quote;
60 static bool StripUnderscore;
61 static bool Types;
62 
63 static StringRef ToolName;
64 
65 static void error(const Twine &Message) {
66   WithColor::error(errs(), ToolName) << Message << '\n';
67   exit(1);
68 }
69 
70 // Quote Undecorated with "" if asked for and not already followed by a '"'.
71 static std::string optionalQuote(const std::string &Undecorated,
72                                  StringRef Delimiters) {
73   if (Quote && (Delimiters.empty() || Delimiters[0] != '"'))
74     return '"' + Undecorated + '"';
75   return Undecorated;
76 }
77 
78 static std::string demangle(const std::string &Mangled, StringRef Delimiters) {
79   using llvm::itanium_demangle::starts_with;
80   std::string_view DecoratedStr = Mangled;
81   bool CanHaveLeadingDot = true;
82   if (StripUnderscore && DecoratedStr[0] == '_') {
83     DecoratedStr.remove_prefix(1);
84     CanHaveLeadingDot = false;
85   }
86 
87   std::string Result;
88   if (nonMicrosoftDemangle(DecoratedStr, Result, CanHaveLeadingDot,
89                            ParseParams))
90     return optionalQuote(Result, Delimiters);
91 
92   std::string Prefix;
93   char *Undecorated = nullptr;
94 
95   if (Types)
96     Undecorated = itaniumDemangle(DecoratedStr, ParseParams);
97 
98   if (!Undecorated && starts_with(DecoratedStr, "__imp_")) {
99     Prefix = "import thunk for ";
100     Undecorated = itaniumDemangle(DecoratedStr.substr(6), ParseParams);
101   }
102 
103   Result =
104       Undecorated ? optionalQuote(Prefix + Undecorated, Delimiters) : Mangled;
105   free(Undecorated);
106   return Result;
107 }
108 
109 // Split 'Source' on any character that fails to pass 'IsLegalChar'.  The
110 // returned vector consists of pairs where 'first' is the delimited word, and
111 // 'second' are the delimiters following that word.
112 static void SplitStringDelims(
113     StringRef Source,
114     SmallVectorImpl<std::pair<StringRef, StringRef>> &OutFragments,
115     function_ref<bool(char)> IsLegalChar) {
116   // The beginning of the input string.
117   const auto Head = Source.begin();
118 
119   // Obtain any leading delimiters.
120   auto Start = std::find_if(Head, Source.end(), IsLegalChar);
121   if (Start != Head)
122     OutFragments.push_back({"", Source.slice(0, Start - Head)});
123 
124   // Capture each word and the delimiters following that word.
125   while (Start != Source.end()) {
126     Start = std::find_if(Start, Source.end(), IsLegalChar);
127     auto End = std::find_if_not(Start, Source.end(), IsLegalChar);
128     auto DEnd = std::find_if(End, Source.end(), IsLegalChar);
129     OutFragments.push_back({Source.slice(Start - Head, End - Head),
130                             Source.slice(End - Head, DEnd - Head)});
131     Start = DEnd;
132   }
133 }
134 
135 // This returns true if 'C' is a character that can show up in an
136 // Itanium-mangled string.
137 static bool IsLegalItaniumChar(char C) {
138   // Itanium CXX ABI [External Names]p5.1.1:
139   // '$' and '.' in mangled names are reserved for private implementations.
140   return isAlnum(C) || C == '.' || C == '$' || C == '_';
141 }
142 
143 // If 'Split' is true, then 'Mangled' is broken into individual words and each
144 // word is demangled.  Otherwise, the entire string is treated as a single
145 // mangled item.  The result is output to 'OS'.
146 static void demangleLine(llvm::raw_ostream &OS, StringRef Mangled, bool Split) {
147   std::string Result;
148   if (Split) {
149     SmallVector<std::pair<StringRef, StringRef>, 16> Words;
150     SplitStringDelims(Mangled, Words, IsLegalItaniumChar);
151     for (const auto &Word : Words)
152       Result +=
153           ::demangle(std::string(Word.first), Word.second) + Word.second.str();
154   } else
155     Result = ::demangle(std::string(Mangled), "");
156   OS << Result << '\n';
157   OS.flush();
158 }
159 
160 int llvm_cxxfilt_main(int argc, char **argv, const llvm::ToolContext &) {
161   BumpPtrAllocator A;
162   StringSaver Saver(A);
163   CxxfiltOptTable Tbl;
164   ToolName = argv[0];
165   opt::InputArgList Args = Tbl.parseArgs(argc, argv, OPT_UNKNOWN, Saver,
166                                          [&](StringRef Msg) { error(Msg); });
167   if (Args.hasArg(OPT_help)) {
168     Tbl.printHelp(outs(),
169                   (Twine(ToolName) + " [options] <mangled>").str().c_str(),
170                   "LLVM symbol undecoration tool");
171     // TODO Replace this with OptTable API once it adds extrahelp support.
172     outs() << "\nPass @FILE as argument to read options from FILE.\n";
173     return 0;
174   }
175   if (Args.hasArg(OPT_version)) {
176     outs() << ToolName << '\n';
177     cl::PrintVersionMessage();
178     return 0;
179   }
180 
181   StripUnderscore =
182       Args.hasFlag(OPT_strip_underscore, OPT_no_strip_underscore, false);
183 
184   ParseParams = !Args.hasArg(OPT_no_params);
185 
186   Quote = Args.hasArg(OPT_quote);
187 
188   Types = Args.hasArg(OPT_types);
189 
190   std::vector<std::string> Decorated = Args.getAllArgValues(OPT_INPUT);
191   if (Decorated.empty())
192     for (std::string Mangled; std::getline(std::cin, Mangled);)
193       demangleLine(llvm::outs(), Mangled, true);
194   else
195     for (const auto &Symbol : Decorated)
196       demangleLine(llvm::outs(), Symbol, false);
197 
198   return EXIT_SUCCESS;
199 }
200