================ @@ -0,0 +1,162 @@ +================ +TypeSanitizer +================ + +.. contents:: + :local: + +Introduction +============ + +The TypeSanitizer is a detector for strict type aliasing violations. It consists of a compiler +instrumentation module and a run-time library. C/C++ has type-based aliasing rules, and LLVM +can exploit these for optimizations given the TBAA metadata Clang emits. In general, a pointer +of a given type cannot access an object of a different type, with only a few exceptions. + +These rules aren't always apparent to users, which leads to code that violates these rules +(e.g. for type punning). This can lead to optimization passes introducing bugs unless the +code is build with ``-fno-strict-aliasing``, sacrificing performance. + +TypeSanitizer is built to catch when these strict aliasing rules have been violated, helping +users find where such bugs originate in their code despite the code looking valid at first glance. + +As TypeSanitizer is still experimental, it can currently have a large impact on runtime speed, +memory use, and code size. + +How to build +============ + +Build LLVM/Clang with `CMake <https://llvm.org/docs/CMake.html>`_ and enable +the ``compiler-rt`` runtime. An example CMake configuration that will allow +for the use/testing of TypeSanitizer: + +.. code-block:: console + + $ cmake -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_PROJECTS="clang" -DLLVM_ENABLE_RUNTIMES="compiler-rt" <path to source>/llvm + +Usage +===== + +Compile and link your program with ``-fsanitize=type`` flag. The ---------------- gbMattN wrote:
From a check, I think its mutually exclusive with all of them currently. I will put this in the **Limitations** section https://github.com/llvm/llvm-project/pull/123595 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
