xref: /freebsd/contrib/llvm-project/llvm/tools/llvm-cxxfilt/llvm-cxxfilt.cpp (revision 6966ac055c3b7a39266fb982493330df7a097997)
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 }
149