derofim / cling-cmake Goto Github PK

enable c++17 in cling

cling_args_storage.push_back("--std=c++17");

https://github.com/root-project/cling/tree/master/tools/demo

This example project uses cling as an external library. It compiles code and calls it, moving values from the compiled part to the interpreted part and back.

It showcases how to use cling as a library, and shows how to set up a simple CMake configuration that uses cling.

use relative paths to scripts

root-project/root#4214

see as example https://github.com/blockspacer/CXXCTP/blob/master/src/ClingInterpreterModule.cpp#L202

Any tutorials or samples you could share?

Best example is official demo: https://github.com/root-project/cling/blob/ee374738072fab73d2b9896c968a000cf0a1bfb4/tools/demo/cling-demo.cpp

Note that in cling-demo.cpp we can use global data and functions freely, as usual (see int aGlobal).

I use install_cling.sh from https://github.com/blockspacer/CXXCTP#how-to-build

Just copy install_cling.sh and FindCling.cmake into your project and link with cling::Interpreter library. CXXCTP is MIT licensed.

Than you can create cling::Interpreter

interpreter_ = std::make_uniquecling::Interpreter( interp_args.size(), &(interp_args[0]), LLVMDIR/, {}, false/);

See https://github.com/blockspacer/CXXCTP/blob/master/src/ClingInterpreterModule.cpp#L165

Than you can run any C++ code:

metaProcessor_->process(".L " + CPP_FILENAME_OR_ANY_CODE_HERE, compilationResult, nullptr, true);

If you want to pass not global data into script - wrap data into struct and convert pointer to that struct into hex string. See std::hex << std::showbase from https://github.com/blockspacer/CXXCTP/blob/master/src/clangPipeline.cpp#L220

Now you can get result of running code in Cling via cling::Value result;

I prefer to pass arbitrary data into cling::Value as void*, like so https://github.com/blockspacer/CXXCTP/blob/master/src/clangPipeline.cpp#L438

A lot of useful links can be found at README.md from https://github.com/derofim/cling-cmake

https://github.com/root-project/cling/tree/master/www/docs/talks https://github.com/caiorss/C-Cpp-Notes/blob/master/Root-cern-repl.org

Use Cling as C++ interpreter. No need to bind variables, just use them as usual.

Pro tip: you can not only use Cling as LUA replacement, but remove Cling in release build (for max. speed).

Cling can also be used for hot-code reload in whole project, no need to recompile anymore!

cd scripts before setup.sh

If you want to use cling, maybe following will be useful:
https://github.com/blockspacer/CXXCTP/blob/master/src/template_engine/engine_main.cpp#L20

Note argRefToCling function, it allows to pass C++ variables into Cling (or maybe it is possible to do it easier).

// Or use macro / codegen
#define ARG_REF_TO_CLING(varType, varName) argRefToCling(varType, #varName, (varName))

Also note that usage example is reflection/codegen engine ( https://github.com/blockspacer/CXXCTP ), may be useful for game engine/level editor/e.t.c.

That project links to boost, add some static libs or:

• Try to use Boost_USE_STATIC_LIBS

Seems like cling does not support static libs, so we must use SHARED libs

• root-project/cling#280
• https://gitlab.kitware.com/cmake/cmake/issues/16473