D programming language (dlang) symbol name demangler for C++

std::cout << demangle_d::demangle("_D3std5stdio__T8writeflnTaTiZQoFNfxAaiZv") << std::endl;
// Will print: void std.stdio.writefln!(char, int)(const char[], int) @safe

Goals

Easy of integration into any C++ codebase
Flexible licensing
Code simplicity following the spec closely in shape

Status

Alpha. It mostly works. For example it can demangle all symbols in Phobos without crashing, invalid accesses or going into infinite loops.

While performance is not its goal (in fact there are is plenty of slow string copying patterns in it), it is not slow. Demangling phobos symbols at a rate of 22000 symbols per second on a weak CPU.

Simple test script is provided to test few symbols.

Missing / untested features:

Underspecified features of demangling spec
wstring and dstring literals
assosciative array literals
inner functions are not demangled properly fully (but it is okish)
64-bit integers and float values are untested (should work, but validation is not complete).

A full fuzzing testing would also be good to have.

Building

Just take d-demangle.h and d-demangle.cc and integrate into your code base.

It can also be built as a library and linked statically or dynamically.

You can also combine both files and use if you want.

Example working Makefile is provided.

Test program

A simple command line interface (similar to c++filt) is provided.

$ make d-demangle
$ ./d-demangle _D3std5stdio__T8writeflnTaTiZQoFNfxAaiZv
void std.stdio.writefln!(char, int)writefln(const char[], int) @safe
$

Check ./d-demangle --help for extra options.

API stability

demangle_d::demangle(const std::string&) will be provided.

Extra parameters or overrides are not guaranteed to exist long term. (But are likely to be easy to change later).

Compatibility

We strive to support C++98 and anything after that. If C++11 is detected, it will internally use std::unordered_map for back references. Otherwise it will use std::map. So no modern features like auto, brace initalization, range based for loops, move semantics, etc.

The intent is code execution correctness and compatibility, not speed.

Routinly tested on gcc and clang on Linux.

Library facilities required: size_t, std::string, std::to_string(size_t) (For C++11. For C++98 it will use sprintf from cstdio), std::runtime_error, standard allocator.

It would be nice to not require exceptions to be enabled. Patches welcome.

If desired std::string can be swapped for any other type with similar interface.

Note: On 32-bit systems, some extremally large or malformed mangled symbols, might fail to demangle. Hopefully just throw exception or return back the input without changes, without crashing or corrupting anything.

The code does not use too many C++ specific or complex features, which should make it easy to port to other languages like C, Go, Rust, Java, JavaScript, Python, PHP or even D, while keeping most of the code the same.

License

To facilitate wide adoption in any other software, the code is multi licensed.

Select any non-empty subset of licenses available for your project.

The Boost Source License (BSL)
MIT License
BSD 3-Clouse license
LGPL License
GPL v2 or later license

Contributing

Contributions, especially for compiler compatibility and correctess are welcome. By submitting pull requests you agree for the code to be released using any of the above licenses (including Copyright lines). You name will remain in the Git history, but not necassarily in a redistributed code.

Coding style follow Google style guidelines in formatting with 80 columns width, and */& in types attached to the variable name. Function names are lower snake case tho.

baryluk / d-demangle-cpp