BillyDonahue / boost_optional_migration

experimental tool to migrate a C++ codebase from boost::optional to std::optional

clang-tool

clang-tool is a simple and powerful project template for clang-based tools using libtooling[1]. It helps getting started to write standalone tools useful for refactoring, static code analysis, auto-completion etc.

Installation

Install the necessary llvm and clang headers and libraries for you system an run:

git clone https://github.com/firolino/clang-tool
cd clang-tool
mkdir build
cd build
cmake ..
make

Usage

A simple example is included in src/transformers/functioncalltransformer.cc that rewriters all function calls from functionName() to fn_functionName().

bin/clang-tool ../examples/simple.cc -- -std=c++11

Another example can be found in finder/integervariablefinder.cc. Uncomment the intFinder in consumer.cc to print all integer variables.

FunctionCallTransformer fntransformer(context, rewriter);
fntransformer.start();
fntransformer.print(llvm::outs());

IntegerVariableFinder intFinder(context);
intFinder.start();

You can even specifiy more than one source file when calling clang-tool.

bin/clang-tool s1.cc s2.cc -- -std=c++11

More matchers for writing own finders and transformers are available under [2].

Specifiying compiler arguments

There are multiple ways to provide your projects' compiler arguments to a clang tool:

• Direct

  As can be seen in the example above, compiler arguments can be placed directly after --.

• Compilation Database

  If your project is CMake-based use -DCMAKE_EXPORT_COMPILE_COMMANDS=ON in your cmake call. It will generate a compile_commands.json in your build directory containing your compiler arguments etc. With the json file you don't need to provide -- anymore. clang-tool will automatically use your json file.

• Makefiles

  If you have an ordinary Makefile based project, use rizsottos awesome tool from https://github.com/rizsotto/Bear and run bear make on a cleanded project directory. It will generate a compile_commands.json for you!

TODOs

Inlude PPCallbacks

References

[1] http://clang.llvm.org/docs/LibTooling.html

[2] http://clang.llvm.org/docs/LibASTMatchersReference.html