xref: /freebsd/contrib/llvm-project/llvm/tools/llvm-cxxfilt/llvm-cxxfilt.cpp (revision dd41de95a84d979615a2ef11df6850622bf6184e)
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/Support/CommandLine.h"
13 #include "llvm/Support/Host.h"
14 #include "llvm/Support/InitLLVM.h"
15 #include "llvm/Support/raw_ostream.h"
16 #include <cstdlib>
17 #include <iostream>
18 
19 using namespace llvm;
20 
21 enum Style {
22   Auto,  ///< auto-detect mangling
23   GNU,   ///< GNU
24   Lucid, ///< Lucid compiler (lcc)
25   ARM,
26   HP,    ///< HP compiler (xCC)
27   EDG,   ///< EDG compiler
28   GNUv3, ///< GNU C++ v3 ABI
29   Java,  ///< Java (gcj)
30   GNAT   ///< ADA compiler (gnat)
31 };
32 static cl::opt<Style>
33     Format("format", cl::desc("decoration style"),
34            cl::values(clEnumValN(Auto, "auto", "auto-detect style"),
35                       clEnumValN(GNU, "gnu", "GNU (itanium) style")),
36            cl::init(Auto));
37 static cl::alias FormatShort("s", cl::desc("alias for --format"),
38                              cl::aliasopt(Format));
39 
40 static cl::opt<bool> StripUnderscore("strip-underscore",
41                                      cl::desc("strip the leading underscore"),
42                                      cl::init(false));
43 static cl::alias StripUnderscoreShort("_",
44                                       cl::desc("alias for --strip-underscore"),
45                                       cl::aliasopt(StripUnderscore));
46 static cl::opt<bool>
47     NoStripUnderscore("no-strip-underscore",
48                       cl::desc("do not strip the leading underscore"),
49                       cl::init(false));
50 static cl::alias
51     NoStripUnderscoreShort("n", cl::desc("alias for --no-strip-underscore"),
52                            cl::aliasopt(NoStripUnderscore));
53 
54 static cl::opt<bool>
55     Types("types",
56           cl::desc("attempt to demangle types as well as function names"),
57           cl::init(false));
58 static cl::alias TypesShort("t", cl::desc("alias for --types"),
59                             cl::aliasopt(Types));
60 
61 static cl::list<std::string>
62 Decorated(cl::Positional, cl::desc("<mangled>"), cl::ZeroOrMore);
63 
64 static cl::extrahelp
65     HelpResponse("\nPass @FILE as argument to read options from FILE.\n");
66 
67 static bool shouldStripUnderscore() {
68   if (StripUnderscore)
69     return true;
70   if (NoStripUnderscore)
71     return false;
72   // If none of them are set, use the default value for platform.
73   // macho has symbols prefix with "_" so strip by default.
74   return Triple(sys::getProcessTriple()).isOSBinFormatMachO();
75 }
76 
77 static std::string demangle(const std::string &Mangled) {
78   int Status;
79   std::string Prefix;
80 
81   const char *DecoratedStr = Mangled.c_str();
82   if (shouldStripUnderscore())
83     if (DecoratedStr[0] == '_')
84       ++DecoratedStr;
85   size_t DecoratedLength = strlen(DecoratedStr);
86 
87   char *Undecorated = nullptr;
88 
89   if (Types ||
90       ((DecoratedLength >= 2 && strncmp(DecoratedStr, "_Z", 2) == 0) ||
91        (DecoratedLength >= 4 && strncmp(DecoratedStr, "___Z", 4) == 0)))
92     Undecorated = itaniumDemangle(DecoratedStr, nullptr, nullptr, &Status);
93 
94   if (!Undecorated &&
95       (DecoratedLength > 6 && strncmp(DecoratedStr, "__imp_", 6) == 0)) {
96     Prefix = "import thunk for ";
97     Undecorated = itaniumDemangle(DecoratedStr + 6, nullptr, nullptr, &Status);
98   }
99 
100   std::string Result(Undecorated ? Prefix + Undecorated : Mangled);
101   free(Undecorated);
102   return Result;
103 }
104 
105 // Split 'Source' on any character that fails to pass 'IsLegalChar'.  The
106 // returned vector consists of pairs where 'first' is the delimited word, and
107 // 'second' are the delimiters following that word.
108 static void SplitStringDelims(
109     StringRef Source,
110     SmallVectorImpl<std::pair<StringRef, StringRef>> &OutFragments,
111     function_ref<bool(char)> IsLegalChar) {
112   // The beginning of the input string.
113   const auto Head = Source.begin();
114 
115   // Obtain any leading delimiters.
116   auto Start = std::find_if(Head, Source.end(), IsLegalChar);
117   if (Start != Head)
118     OutFragments.push_back({"", Source.slice(0, Start - Head)});
119 
120   // Capture each word and the delimiters following that word.
121   while (Start != Source.end()) {
122     Start = std::find_if(Start, Source.end(), IsLegalChar);
123     auto End = std::find_if_not(Start, Source.end(), IsLegalChar);
124     auto DEnd = std::find_if(End, Source.end(), IsLegalChar);
125     OutFragments.push_back({Source.slice(Start - Head, End - Head),
126                             Source.slice(End - Head, DEnd - Head)});
127     Start = DEnd;
128   }
129 }
130 
131 // This returns true if 'C' is a character that can show up in an
132 // Itanium-mangled string.
133 static bool IsLegalItaniumChar(char C) {
134   // Itanium CXX ABI [External Names]p5.1.1:
135   // '$' and '.' in mangled names are reserved for private implementations.
136   return isalnum(C) || C == '.' || C == '$' || C == '_';
137 }
138 
139 // If 'Split' is true, then 'Mangled' is broken into individual words and each
140 // word is demangled.  Otherwise, the entire string is treated as a single
141 // mangled item.  The result is output to 'OS'.
142 static void demangleLine(llvm::raw_ostream &OS, StringRef Mangled, bool Split) {
143   std::string Result;
144   if (Split) {
145     SmallVector<std::pair<StringRef, StringRef>, 16> Words;
146     SplitStringDelims(Mangled, Words, IsLegalItaniumChar);
147     for (const auto &Word : Words)
148       Result += ::demangle(std::string(Word.first)) + Word.second.str();
149   } else
150     Result = ::demangle(std::string(Mangled));
151   OS << Result << '\n';
152   OS.flush();
153 }
154 
155 int main(int argc, char **argv) {
156   InitLLVM X(argc, argv);
157 
158   cl::ParseCommandLineOptions(argc, argv, "llvm symbol undecoration tool\n");
159 
160   if (Decorated.empty())
161     for (std::string Mangled; std::getline(std::cin, Mangled);)
162       demangleLine(llvm::outs(), Mangled, true);
163   else
164     for (const auto &Symbol : Decorated)
165       demangleLine(llvm::outs(), Symbol, false);
166 
167   return EXIT_SUCCESS;
168 }
169