1 // Copyright 2018 The Abseil Authors. 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // https://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 #ifndef ABSL_DEBUGGING_INTERNAL_DEMANGLE_H_ 16 #define ABSL_DEBUGGING_INTERNAL_DEMANGLE_H_ 17 18 #include <string> 19 #include "absl/base/config.h" 20 21 namespace absl { 22 ABSL_NAMESPACE_BEGIN 23 namespace debugging_internal { 24 25 // Demangle `mangled`. On success, return true and write the 26 // demangled symbol name to `out`. Otherwise, return false. 27 // `out` is modified even if demangling is unsuccessful. 28 // 29 // This function provides an alternative to libstdc++'s abi::__cxa_demangle, 30 // which is not async signal safe (it uses malloc internally). It's intended to 31 // be used in async signal handlers to symbolize stack traces. 32 // 33 // Note that this demangler doesn't support full demangling. More 34 // specifically, it doesn't print types of function parameters and 35 // types of template arguments. It just skips them. However, it's 36 // still very useful to extract basic information such as class, 37 // function, constructor, destructor, and operator names. 38 // 39 // See the implementation note in demangle.cc if you are interested. 40 // 41 // Example: 42 // 43 // | Mangled Name | Demangle | DemangleString 44 // |---------------|-------------|----------------------- 45 // | _Z1fv | f() | f() 46 // | _Z1fi | f() | f(int) 47 // | _Z3foo3bar | foo() | foo(bar) 48 // | _Z1fIiEvi | f<>() | void f<int>(int) 49 // | _ZN1N1fE | N::f | N::f 50 // | _ZN3Foo3BarEv | Foo::Bar() | Foo::Bar() 51 // | _Zrm1XS_" | operator%() | operator%(X, X) 52 // | _ZN3FooC1Ev | Foo::Foo() | Foo::Foo() 53 // | _Z1fSs | f() | f(std::basic_string<char, 54 // | | | std::char_traits<char>, 55 // | | | std::allocator<char> >) 56 // 57 // See the unit test for more examples. 58 // 59 // Demangle also recognizes Rust mangled names by delegating the parsing of 60 // anything that starts with _R to DemangleRustSymbolEncoding (demangle_rust.h). 61 // 62 // Note: we might want to write demanglers for ABIs other than Itanium 63 // C++ ABI in the future. 64 bool Demangle(const char* mangled, char* out, size_t out_size); 65 66 // A wrapper around `abi::__cxa_demangle()`. On success, returns the demangled 67 // name. On failure, returns the input mangled name. 68 // 69 // This function is not async-signal-safe. 70 std::string DemangleString(const char* mangled); 71 72 } // namespace debugging_internal 73 ABSL_NAMESPACE_END 74 } // namespace absl 75 76 #endif // ABSL_DEBUGGING_INTERNAL_DEMANGLE_H_ 77