Cpptrace

🚧 WIP 🏗️

Cpptrace is a lightweight C++ stacktrace library supporting C++11 and greater on Linux, Unix, macOS and Windows. The goal: Make stack traces simple for once.

Support for cygwin/mingw will be added soon.

Some day C++23's <stacktrace> will be ubiquitous. And maybe one day the msvc implementation will be acceptable.

Table of contents

• Cpptrace
  • Table of contents
  • How to use
    • CMake FetchContent
    • System-wide installation
    • Conan
    • Vcpkg
  • Docs
  • Back-ends
  • License

How to use

CMake FetchContent

TODO

System-wide installation

TODO

Conan

TODO

Vcpkg

TODO

Docs

cpptrace::print_trace() can be used to print a stacktrace at the current call site, cpptrace::generate_trace() can be used to get raw frame information for custom use.

Note: Debug info (-g) is generally required for good trace information. Some back-ends read symbols from dynamic export information which may require -rdynamic or manually marking symbols for exporting.

namespace cpptrace {
    struct stacktrace_frame {
        uintptr_t address;
        std::uint_least32_t line;
        std::uint_least32_t col;
        std::string filename;
        std::string symbol;
    };
    std::vector<stacktrace_frame> generate_trace(std::uint32_t skip = 0);
    void print_trace(std::uint32_t skip = 0);
}

Back-ends

Back-end libraries are required for unwinding the stack and resolving symbol information (name and source location) in order to generate a stacktrace.

The CMake script attempts to automatically choose a good back-end based on what is available on your system. You can also manually set which back-end you want used.

Unwinding

Library	CMake config	Windows	Linux	macOS	Info
execinfo.h	CPPTRACE_UNWIND_WITH_EXECINFO	❌	✔️	✔️	Frames are captured with execinfo.h's backtrace, part of libc.
winapi	CPPTRACE_UNWIND_WITH_WINAPI	✔️	❌	❌	Frames are captured with CaptureStackBackTrace.
N/A	CPPTRACE_UNWIND_WITH_NOTHING	✔️	✔️	✔️	Unwinding is not done, stack traces will be empty.

These back-ends require a fixed buffer has to be created to read addresses into while unwinding. By default the buffer can hold addresses for 100 frames (beyond the skip frames). This is configurable with CPPTRACE_HARD_MAX_FRAMES.

Symbol resolution

Library	CMake config	Windows	Linux	macOS	Info
libbacktrace	CPPTRACE_GET_SYMBOLS_WITH_LIBBACKTRACE	❌	✔️	❌	Libbacktrace is already installed on most systems, or available through the compiler directly. If it is installed but backtrace.h is not already in the include path (this can happen when using clang when backtrace lives in gcc's include folder), CPPTRACE_BACKTRACE_PATH can be used to specify where the library should be looked for.
libdl	CPPTRACE_GET_SYMBOLS_WITH_LIBDL	❌	✔️	✔️	Libdl uses dynamic export information. Compiling with -rdynamic is needed for symbol information to be retrievable.
addr2line	CPPTRACE_GET_SYMBOLS_WITH_ADDR2LINE	❌	✔️	❌ (TODO)	Symbols are resolved by invoking addr2line via fork().
dbghelp	CPPTRACE_GET_SYMBOLS_WITH_DBGHELP	✔️	❌	❌	Dbghelp.h allows access to symbols via debug info.
N/A	CPPTRACE_GET_SYMBOLS_WITH_NOTHING	✔️	✔️	✔️	No attempt is made to resolve symbols.

Demangling

Lastly, depending on other back-ends used a demangler back-end may be needed. A demangler back-end is not needed when doing full traces with libbacktrace, getting symbols with addr2line, or getting symbols with dbghelp.

Library	CMake config	Windows	Linux	Info
cxxabi.h	CPPTRACE_DEMANGLE_WITH_CXXABI			Should be available everywhere other than msvc.
N/A	CPPTRACE_DEMANGLE_WITH_NOTHING			Don't attempt to do anything beyond what the symbol resolution back-end does.

Full tracing

Libbacktrace can generate a full stack trace itself, both unwinding and resolving symbols. This can be chosen with CPPTRACE_FULL_TRACE_WITH_LIBBACKTRACE. The auto config attempts to use this if it is available. Full tracing with libbacktrace ignores CPPTRACE_HARD_MAX_FRAMES.

<stacktrace> can of course also generate a full trace, if you're using >=C++23 and your compiler supports it. This is controlled by CPPTRACE_FULL_TRACE_WITH_LIBBACKTRACE. The cmake script will attempt to auto configure to this if possible. CPPTRACE_HARD_MAX_FRAMES is ignored.

More?

There are plenty more libraries that can be used for unwinding, parsing debug information, and demangling. In the future more back-ends can be added. Ideally this library can "just work" on systems, without additional installation work.

License

The library is under the MIT license.