xref: /llvm-project/llvm/lib/Demangle/Demangle.cpp (revision 0b554dd9b1932c76225afded64d5f4cc7bb2933f)
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 "llvm/Demangle/StringViewExtras.h"
15 #include <cstdlib>
16 #include <string_view>
17 
18 using llvm::itanium_demangle::starts_with;
19 
20 std::string llvm::demangle(std::string_view MangledName) {
21   std::string Result;
22 
23   if (nonMicrosoftDemangle(MangledName, Result))
24     return Result;
25 
26   if (starts_with(MangledName, '_') &&
27       nonMicrosoftDemangle(MangledName.substr(1), Result,
28                            /*CanHaveLeadingDot=*/false))
29     return Result;
30 
31   if (char *Demangled = microsoftDemangle(MangledName, nullptr, nullptr)) {
32     Result = Demangled;
33     std::free(Demangled);
34   } else {
35     Result = MangledName;
36   }
37   return Result;
38 }
39 
40 static bool isItaniumEncoding(std::string_view S) {
41   // Itanium demangler supports prefixes with 1-4 underscores.
42   const size_t Pos = S.find_first_not_of('_');
43   return Pos > 0 && Pos <= 4 && S[Pos] == 'Z';
44 }
45 
46 static bool isRustEncoding(std::string_view S) { return starts_with(S, "_R"); }
47 
48 static bool isDLangEncoding(std::string_view S) { return starts_with(S, "_D"); }
49 
50 bool llvm::nonMicrosoftDemangle(std::string_view MangledName,
51                                 std::string &Result, bool CanHaveLeadingDot,
52                                 bool ParseParams) {
53   char *Demangled = nullptr;
54 
55   // Do not consider the dot prefix as part of the demangled symbol name.
56   if (CanHaveLeadingDot && MangledName.size() > 0 && MangledName[0] == '.') {
57     MangledName.remove_prefix(1);
58     Result = ".";
59   }
60 
61   if (isItaniumEncoding(MangledName))
62     Demangled = itaniumDemangle(MangledName, ParseParams);
63   else if (isRustEncoding(MangledName))
64     Demangled = rustDemangle(MangledName);
65   else if (isDLangEncoding(MangledName))
66     Demangled = dlangDemangle(MangledName);
67 
68   if (!Demangled)
69     return false;
70 
71   Result += Demangled;
72   std::free(Demangled);
73   return true;
74 }
75