include/llvm/Support/TypeName.h

   1 //===- TypeName.h -----------------------------------------------*- C++ -*-===//
   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 #ifndef LLVM_SUPPORT_TYPENAME_H
  10 #define LLVM_SUPPORT_TYPENAME_H
  11
  12 #include "llvm/ADT/StringRef.h"
  13
  14 namespace llvm {
  15
  16 /// We provide a function which tries to compute the (demangled) name of a type
  17 /// statically.
  18 ///
  19 /// This routine may fail on some platforms or for particularly unusual types.
  20 /// Do not use it for anything other than logging and debugging aids. It isn't
  21 /// portable or dependendable in any real sense.
  22 ///
  23 /// The returned StringRef will point into a static storage duration string.
  24 /// However, it may not be null terminated and may be some strangely aligned
  25 /// inner substring of a larger string.
  26 template <typename DesiredTypeName>
  27 inline StringRef getTypeName() {
  28 #if defined(__clang__) || defined(__GNUC__)
  29   StringRef Name = __PRETTY_FUNCTION__;
  30
  31   StringRef Key = "DesiredTypeName = ";
  32   Name = Name.substr(Name.find(Key));
  33   assert(!Name.empty() && "Unable to find the template parameter!");
  34   Name = Name.drop_front(Key.size());
  35
  36   assert(Name.endswith("]") && "Name doesn't end in the substitution key!");
  37   return Name.drop_back(1);
  38 #elif defined(_MSC_VER)
  39   StringRef Name = __FUNCSIG__;
  40
  41   StringRef Key = "getTypeName<";
  42   Name = Name.substr(Name.find(Key));
  43   assert(!Name.empty() && "Unable to find the function name!");
  44   Name = Name.drop_front(Key.size());
  45
  46   for (StringRef Prefix : {"class ", "struct ", "union ", "enum "})
  47     if (Name.startswith(Prefix)) {
  48       Name = Name.drop_front(Prefix.size());
  49       break;
  50     }
  51
  52   auto AnglePos = Name.rfind('>');
  53   assert(AnglePos != StringRef::npos && "Unable to find the closing '>'!");
  54   return Name.substr(0, AnglePos);
  55 #else
  56   // No known technique for statically extracting a type name on this compiler.
  57   // We return a string that is unlikely to look like any type in LLVM.
  58   return "UNKNOWN_TYPE";
  59 #endif
  60 }
  61
  62 }
  63
  64 #endif