LiteFMWK

LiteFMWK is a software development base that allows you to:

• Generate a software package where you can generate arbitrary number of C++ class/function and compile into 1 library
• Automatically generate ROOT cling dictionary to access compiled class/function from cling/python interpreters (latter via PyROOT)
• Support a structure for introducing inter-package dependencies

How to use it?

Just try:

source setup.sh

This sets up necessary shell env. variables. You need to have ROOT6 (if not, you get an error message from setup.sh). There's a support to detect numpy and provide a few handy compiler directives as well.

How to make a new package?

Just try:

gen_my_package Aho

... which will generate a directory named Aho under the repository top directory. A new package comes with GNUmakefile which allows you to compile a package by simply typing make in the package directory. You also find sample.h and sample.cxx. These are very much empty C++ classes just to demonstrate that you can make and access them from an interpreter.

python -c "import ROOT;print ROOT.Aho.sample()"

Generating a new class

In a package directory you can generate a new class. You can of course just type-it-up from scratch. You can also try:

gen_my_class Tako

... which generates Tako.h and Tako.cxx much like sample class. Again, to compile, you can just type make.

If you have written your class from scratch, make sure you add your class to LinkDef.h if you want a dictionary generation (e.g. if you want an access from an interpreter).

Example?

You can find an example in this branch:

git checkout example

Compiling multiple packages

No one wants to cd package directory and make for every package. You can utilize the top level GNUmakefile which is extremely simple and hopefully self-descriptive. All you need to do is to list (space-separated) packages in SUBDIRS variable.

Excluding a class from dictionary generation

Sometimes you don't want to expose your C++ class to an interpreter. Assuming your C++ class is already registered in the dictionary (a mechanism to make your class available in an interpreter), simply exclude it from LinkDef.h.

If you wonder when you want to do it, here's some example reasons:

• Compilation is so slow (auto-generated dictionary source code is usually really long, like easily 10,000 lines, taking long time to compile)
• Ugh I keep getting dictionary compilation error (auto-generation of dictionary source code is far from being perfect, especially for the latest C++ standards... if troublesome, exclude)

Making inter-package dependencies

To make one package depend on another, you typically want to know 2 information: headers to be included and libraries to be linked against. Here are two pieces of information you may find it useful/handy:

• Package libraries are compiled and available under $MYSW_LIBDIR/libLiteFMWK_$(PACKAGE_NAME).so
• Package header files are copied and available under $MYSW_INCDIR/litefmwk/$(PACKAGE_NAME) ... where you substitute $(PACKAGE_NAME) with the actual name string.

With these info, you know what you need to do for your new package compilation that depends on those.

1. Add compiler flags

• -I$(MYSW_INCDIR)
• -L$(MYSW_LIBDIR) -lLiteFMWK_$(PACKAGE_NAME).so

2. Include statements in the source codes

• #include "litefmwk/$(PACKAGE_NAME)/$(WANTED_HEADER)"
• ... where $(WANTED_HEADER) is the header file you want (like sample.h).