xref: /freebsd/contrib/llvm-project/llvm/tools/llvm-cxxfilt/llvm-cxxfilt.cpp (revision 7a6dacaca14b62ca4b74406814becb87a3fefac0)
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 PREFIX(NAME, VALUE)                                                    \
35   static constexpr llvm::StringLiteral NAME##_init[] = VALUE;                  \
36   static constexpr llvm::ArrayRef<llvm::StringLiteral> NAME(                   \
37       NAME##_init, std::size(NAME##_init) - 1);
38 #include "Opts.inc"
39 #undef PREFIX
40 
41 using namespace llvm::opt;
42 static constexpr opt::OptTable::Info InfoTable[] = {
43 #define OPTION(...) LLVM_CONSTRUCT_OPT_INFO(__VA_ARGS__),
44 #include "Opts.inc"
45 #undef OPTION
46 };
47 
48 class CxxfiltOptTable : public opt::GenericOptTable {
49 public:
50   CxxfiltOptTable() : opt::GenericOptTable(InfoTable) {
51     setGroupedShortOptions(true);
52   }
53 };
54 } // namespace
55 
56 static bool ParseParams;
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   using llvm::itanium_demangle::starts_with;
69   std::string_view DecoratedStr = Mangled;
70   bool CanHaveLeadingDot = true;
71   if (StripUnderscore && DecoratedStr[0] == '_') {
72     DecoratedStr.remove_prefix(1);
73     CanHaveLeadingDot = false;
74   }
75 
76   std::string Result;
77   if (nonMicrosoftDemangle(DecoratedStr, Result, CanHaveLeadingDot,
78                            ParseParams))
79     return Result;
80 
81   std::string Prefix;
82   char *Undecorated = nullptr;
83 
84   if (Types)
85     Undecorated = itaniumDemangle(DecoratedStr, ParseParams);
86 
87   if (!Undecorated && starts_with(DecoratedStr, "__imp_")) {
88     Prefix = "import thunk for ";
89     Undecorated = itaniumDemangle(DecoratedStr.substr(6), ParseParams);
90   }
91 
92   Result = Undecorated ? Prefix + Undecorated : Mangled;
93   free(Undecorated);
94   return Result;
95 }
96 
97 // Split 'Source' on any character that fails to pass 'IsLegalChar'.  The
98 // returned vector consists of pairs where 'first' is the delimited word, and
99 // 'second' are the delimiters following that word.
100 static void SplitStringDelims(
101     StringRef Source,
102     SmallVectorImpl<std::pair<StringRef, StringRef>> &OutFragments,
103     function_ref<bool(char)> IsLegalChar) {
104   // The beginning of the input string.
105   const auto Head = Source.begin();
106 
107   // Obtain any leading delimiters.
108   auto Start = std::find_if(Head, Source.end(), IsLegalChar);
109   if (Start != Head)
110     OutFragments.push_back({"", Source.slice(0, Start - Head)});
111 
112   // Capture each word and the delimiters following that word.
113   while (Start != Source.end()) {
114     Start = std::find_if(Start, Source.end(), IsLegalChar);
115     auto End = std::find_if_not(Start, Source.end(), IsLegalChar);
116     auto DEnd = std::find_if(End, Source.end(), IsLegalChar);
117     OutFragments.push_back({Source.slice(Start - Head, End - Head),
118                             Source.slice(End - Head, DEnd - Head)});
119     Start = DEnd;
120   }
121 }
122 
123 // This returns true if 'C' is a character that can show up in an
124 // Itanium-mangled string.
125 static bool IsLegalItaniumChar(char C) {
126   // Itanium CXX ABI [External Names]p5.1.1:
127   // '$' and '.' in mangled names are reserved for private implementations.
128   return isAlnum(C) || C == '.' || C == '$' || C == '_';
129 }
130 
131 // If 'Split' is true, then 'Mangled' is broken into individual words and each
132 // word is demangled.  Otherwise, the entire string is treated as a single
133 // mangled item.  The result is output to 'OS'.
134 static void demangleLine(llvm::raw_ostream &OS, StringRef Mangled, bool Split) {
135   std::string Result;
136   if (Split) {
137     SmallVector<std::pair<StringRef, StringRef>, 16> Words;
138     SplitStringDelims(Mangled, Words, IsLegalItaniumChar);
139     for (const auto &Word : Words)
140       Result += ::demangle(std::string(Word.first)) + Word.second.str();
141   } else
142     Result = ::demangle(std::string(Mangled));
143   OS << Result << '\n';
144   OS.flush();
145 }
146 
147 int llvm_cxxfilt_main(int argc, char **argv, const llvm::ToolContext &) {
148   BumpPtrAllocator A;
149   StringSaver Saver(A);
150   CxxfiltOptTable Tbl;
151   ToolName = argv[0];
152   opt::InputArgList Args = Tbl.parseArgs(argc, argv, OPT_UNKNOWN, Saver,
153                                          [&](StringRef Msg) { error(Msg); });
154   if (Args.hasArg(OPT_help)) {
155     Tbl.printHelp(outs(),
156                   (Twine(ToolName) + " [options] <mangled>").str().c_str(),
157                   "LLVM symbol undecoration tool");
158     // TODO Replace this with OptTable API once it adds extrahelp support.
159     outs() << "\nPass @FILE as argument to read options from FILE.\n";
160     return 0;
161   }
162   if (Args.hasArg(OPT_version)) {
163     outs() << ToolName << '\n';
164     cl::PrintVersionMessage();
165     return 0;
166   }
167 
168   // The default value depends on the default triple. Mach-O has symbols
169   // prefixed with "_", so strip by default.
170   if (opt::Arg *A =
171           Args.getLastArg(OPT_strip_underscore, OPT_no_strip_underscore))
172     StripUnderscore = A->getOption().matches(OPT_strip_underscore);
173   else
174     StripUnderscore = Triple(sys::getProcessTriple()).isOSBinFormatMachO();
175 
176   ParseParams = !Args.hasArg(OPT_no_params);
177 
178   Types = Args.hasArg(OPT_types);
179 
180   std::vector<std::string> Decorated = Args.getAllArgValues(OPT_INPUT);
181   if (Decorated.empty())
182     for (std::string Mangled; std::getline(std::cin, Mangled);)
183       demangleLine(llvm::outs(), Mangled, true);
184   else
185     for (const auto &Symbol : Decorated)
186       demangleLine(llvm::outs(), Symbol, false);
187 
188   return EXIT_SUCCESS;
189 }
190