Building

Prerequisites:

• CMake version 3.1 or newer.
• YAJL 2.0.1 or newer. You need both the library and the header files. This is a standard binary package in most any Linux distribution. Note that the header files are often in a separate “devel” package. The source can be downloaded from https://github.com/lloyd/yajl/releases if you must build the library yourself.
• A Fortran compiler that supports the 2003/2008 features used by YAJL-Fort, and its companion (or a compatible) C compiler.

Clone the YAJL-Fort source repository with SSH:

git clone git@github.com:nncarlson/yajl-fort.git

or with HTTPS:

git clone https://github.com/nncarlson/yajl-fort.git

Set your FC and CC environment variables to your Fortran and C compilers. If YAJL is not in a standard location you will also need to set your YAJL_ROOT environment variable to the root directory of the YAJL installation. Then create a build directory and run cmake from the directory:

cd yajl-fort
mkdir build
cd build
cmake ..

CMake should find your compilers with the help of the FC and CC variables. The default is to configure a Release build. Some CMake variables you might want to set on the cmake command line:

• CMAKE_BUILD_TYPE: to specify a Debug build type, for example
• CMAKE_Fortran_FLAGS: additional Fortran compiler flags
• CMAKE_INSTALL_PREFIX: where to install the library and module files

Then compile the library and tests, and run the tests (all should pass):

make
ctest

Then see the documentation for the yajl_fort and json modules and the examples therein.

Compiler status and notes

The following compilers are known to work:

• NAG 5.3.2, 6.0, 6.1, and 6.2
• Intel 16.0.2, 17.0.6, 18.0.1
• GFortran 6.4.1, 7.2.1, 7.3.1, 8.1, 8.2
• IBM xlf 15.1.6, 16.1.0 (must use the xlf2008 executable)

The following compilers appear to work now. All tests are passing but the interface has not been extensively exercised in actual applications.

• Flang March 2019 Binary Release (but no earlier)
• PGI 19.4 (but no earlier)

The CMakeLists.txt file has special stanzas for some compilers that set compiler flags and preprocessor macros that are known to be needed. If you are using another compiler it too may need specific compiler flags or macros defined. These can be set on the cmake command line with CMAKE_Fortran_FLAGS or a stanza can be added to the CMakeLists.txt file.