FC - LLVM Based fortran frontend

A new front end for Fortran has been written in the design spirit of LLVM/Clang. Approximately 20000 lines of code effort has got close to Fortran 95 standard. The Front end is complete end to end solution without semantic analysis. It compiles 400+ unit test cases and 2 SPEC CPU 2017 benchmarks.

Dependencies

LLVM 7.0 - Can be built from source or prebuilt binaries can be used.
gfortran (for running unit tests)

Build instructions

1. Set following environment variables
    a. CLANG_BINARY=<path/to/llvm/instal>bin/clang
    b. PATH=<path/to/llvm/install/>/bin:$PATH
    c. LD_LIBRARY_PATH=<path/to/install/>/lib;$PATH
2. mkdir build && cd build
3. cmake -G Ninja -DLLVM_DIR=<path/to/llvm>/lib/cmake/llvm/ ../fc -DCMAKE_INSTALL_PREFIX=<install-prefix> -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++
4. ninja install
5. ninja test


Note that clang-7.0 is already in your PATH. This will be used for building FC.

Running HelloWorld

$ cat hello.f90
program hello
  print *, "Hello world!"
end program hello
$ export CLANG_BINARY=<path/to/llvm/install>/bin/clang
$ export LD_LIBRARY_PATH=<path/to/fc/install>/lib:$LD_LIBRARY_PATH
$ <path/to/fc>/bin/fc hello.f90
$ ./a.out
Hello world!

Running test

cd build
ctest 

OR

cd build
ninja test

Compiling input file to AST

fc <inputfile> -emit-ast

OR

fc <inputfile> -emit-ast -o <ast_output_file>

Emitting LLVM IR

fc <inputfile> -emit-llvm

Emitting LLVM BC

fc <inputfile> -emit-bc

Fortran standard

Fortran standard can be specified via -std=f77 or -std=f95. If not specified standard is derived from file extension. Source files with ".f" are compiled to F77 standard and all other extensions are compiled to default standard.

Enter following command for more options

fc --help

Developed by

CompilerTree Technologies