xref: /llvm-project/llvm/lib/Demangle/Demangle.cpp (revision 61e1c3d80db6e94e8b5b83b3819afefeec4d357b)
1 //===-- Demangle.cpp - Common demangling functions ------------------------===//
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 /// \file This file contains definitions of common demangling functions.
10 ///
11 //===----------------------------------------------------------------------===//
12 
13 #include "llvm/Demangle/Demangle.h"
14 #include <cstdlib>
15 #include <cstring>
16 
17 static bool isItaniumEncoding(const char *S) {
18   // Itanium encoding requires 1 or 3 leading underscores, followed by 'Z'.
19   return std::strncmp(S, "_Z", 2) == 0 || std::strncmp(S, "___Z", 4) == 0;
20 }
21 
22 static bool isRustEncoding(const char *S) { return S[0] == '_' && S[1] == 'R'; }
23 
24 static bool isDLangEncoding(const std::string &MangledName) {
25   return MangledName.size() >= 2 && MangledName[0] == '_' &&
26          MangledName[1] == 'D';
27 }
28 
29 std::string llvm::demangle(const std::string &MangledName) {
30   std::string Result;
31   const char *S = MangledName.c_str();
32 
33   if (nonMicrosoftDemangle(MangledName, Result))
34     return Result;
35 
36   if (S[0] == '_' && nonMicrosoftDemangle(MangledName.substr(1), Result))
37     return Result;
38 
39   if (char *Demangled = microsoftDemangle(S, nullptr, nullptr)) {
40     Result = Demangled;
41     std::free(Demangled);
42     return Result;
43   }
44 
45   return MangledName;
46 }
47 
48 bool llvm::nonMicrosoftDemangle(std::string_view MangledName,
49                                 std::string &Result) {
50   char *Demangled = nullptr;
51   if (isItaniumEncoding(MangledName.data()))
52     Demangled = itaniumDemangle(MangledName);
53   else if (isRustEncoding(MangledName.data()))
54     Demangled = rustDemangle(MangledName.data());
55   else if (isDLangEncoding(MangledName.data()))
56     Demangled = dlangDemangle(MangledName.data());
57 
58   if (!Demangled)
59     return false;
60 
61   Result = Demangled;
62   std::free(Demangled);
63   return true;
64 }
65