Fortran newsletter: September 2021

Welcome to the September 2021 edition of the monthly Fortran newsletter. The newsletter comes out at the beginning of every month and details Fortran news from the previous month.

This month we’ve had several updates to the website:

  • #303: Add NJOY to package index

Work in progress

  • #302 (WIP): Update Silverfrost compiler description.

  • #300 (WIP): Add QCxMS to package index

  • #246 (WIP): Transferring “Fortran Best Practices” into a mini-book

  • #201 (WIP): Internationalization for fortran-lang

Let us know if you have any suggestions for the website and its content. We welcome any new contributors to the website and the tutorials page in particular - see the contributor guide for how to get started.

Fortran Standard Library

Here’s what’s new in stdlib:

  • #467: Implemented move_alloc for string_type

  • #470: Revival string list

  • #481: [stdlib_linalg] Update eye function.

  • #493: Update copyright and remove old artifact

  • #444: Add format_string routine to format other types to strings

  • #483: Remove GCC Fortran MinGW 8.4.0 from known to work list

Work in progress

  • #501 (WIP): Minor updates to

  • #500 (WIP): Selection algorithms

  • #499 (WIP): [stdlib_linalg] matrix property checks

  • #498 (WIP): [stdlib_math] add arg/argd/argpi

  • #494 (WIP): Add testing module to allow better structuring of test suites

  • #491 (WIP): Stdlib linked list

  • #488 (WIP): [stdlib_math] add is_close routines.

  • #478 (WIP): [stdlib_linalg] Add zeros, ones function.

  • #475 (WIP): Generating sorting subroutines specific to character type with fypp

  • #473 (WIP): Error stop improvements

  • #455 (WIP): stdlib_hash: waterhash algorithm

  • #452 (WIP): Implementation of a map data type

  • #445 (WIP): [stdlib_io] disp(display your data)

  • #437 (WIP): [FPM] add fpm support

  • #363 (WIP): Sorting string’s characters according to their ASCII values

  • #353 (WIP): Initial checkin for a module for tolerant comparison of reals

  • #286 (WIP): Probability Distribution and Statistical Functions – Beta Distribution Module

  • #278 (WIP): Probability Distribution and Statistical Functions – Gamma Distribution Module

  • #276 (WIP): Probability Distribution and Statistical Functions – Exponential Distribution Module

  • #273 (WIP): Probability Distribution and Statistical Functions – Normal Distribution Module

  • #272 (WIP): Probability Distribution and Statistical Functions – Uniform Distribution Module

  • #189 (WIP): Initial implementation of COO / CSR sparse format

Please help improve stdlib by testing and reviewing pull requests!

The candidate for file system operations to be included in stdlib is being developed by @MarDiehl and @arjenmarkus in this repository. Please try it out and let us know how it works, if there are any issues, or if the API can be improved.

Fortran Package Manager

Here’s what’s new in fpm:

  • Version 0.4.0: Alpha release update

  • #546: Update version for release 0.4.0

  • #548: Fix build on MacOS/ARM64

  • #527: Add objects for handling compiler and archiver

  • #536: Always call git init in fpm new when backfilling

  • #533: Allow extra section in package manifest

  • #528: Generate build/.gitignore

Work in progress

  • #539 (WIP): Add parent packages into dependency tree

  • #521 (WIP): Expand tabs in source parsing

  • #506 (WIP): Initial implementation of implicit_none

  • #498 (WIP): Compiler flags profiles

fpm is still in early development and we need as much help as we can get. Here’s how you can help today:

  • Use it and let us know what you think! Read the fpm packaging guide to learn how to build your package with fpm, and the manifest reference to learn what are all the things that you can specify in the fpm.toml file.

  • Browse existing fpm packages on the fortran-lang website

  • Browse the open issues and see if you can help implement any fixes or features.

  • Adapt your Fortran package for fpm and submit it to the Registry.

  • Improve the documentation.

The short-term goal of fpm is to make development and installation of Fortran packages with dependencies easier. Its long term goal is to build a rich and decentralized ecosystem of Fortran packages and create a healthy environment in which new open source Fortran projects are created and published with ease.


Zuo Zhihua (@zoziha) and Ondřej Čertík (@certik) started maintaining the public domain project FFTPACK under the Fortran-lang namespace. The project is readily available for usage in with fpm.

Here is what is new in FFTPACK:

  • #10: Add (i)qct/dcosqi/dcosqf/dcosqb interfaces for quarter wave data.

  • #7: Add dzffti/dzfftf/dzfftb interfaces

  • #4: Improve fft interface for complex sequences: (i)fft/zffti/zfftf/zfftb

  • #6: Add (i)rfft/dffti/dfftf/dfftb interface and ready to move to fortran-lang

  • #5: Add fftshift/ifftshift

  • #3: Add CI: fpm.yml

Work in progress

  • #11 (WIP): Add (i)dct/dcosti/dcost interfaces.

Feedback and ideas for this project are welcome.



Recent development updates:

  • New Driver and CMake integration:

    • The new driver has replaced the old, hence f18 has been deleted.

    • flang-new (aka. the new driver) now drives the flang bash script before an external compiler is called.

    • Code-generation work is ongoing.

    • Work is now proceeding to enable CMake to recognize the compiler and set the appropriate options for build configurations.

  • FIR (Fortran IR - a dialect of MLIR):

    • Fortran 95 lowering and runtime support is nearing completion, particularly of intrinsics

    • Code upstreaming will begin again in earnest once F95 is deemed complete

  • OpenMP

    • Nesting of region semantic checks

    • enter_data MLIR to LLVM IR lowering

    • Semantic checks for allocate directive

    • Lowering for various modifiers for the schedule clause

    • Pretty printer and parser for operation

    • Semantic checks for linear, nested barrier, allocate directive

    • Progress with firstprivate, critical, collapse, ordered, reduction

  • Lift -Werror checks into local functions

  • Document the flang wrapper script

  • Fix the extent calculation when upper bounds are less than lower bounds

  • Fix list-directed plural repeated null values at end of record

  • Fix build failure on MacOS involving std::clock_t

  • Fix error messages on Windows.

  • Disable Plugins in out-of-tree builds

  • Correct off-by-one error in SET_EXPONENT

Call notes are recorded and available upon request here. Please contact Alexis Perry-Holby at for document access.


LFortran 0.12.0 was released on August 15

Changes since the last release.

  • Fixed all issues in the parser that were reported (AST)

    • multiple loop single end do

    • arithmetic if

  • Comments and empty lines are now represented in AST and formatted correctly (AST)

  • The formatter (lfortran fmt) now uses the minimal amount of parentheses in expressions

  • Initial fixed-form parser (AST)

  • Initial class support (ASR, LLVM)

  • Allocate / deallocate, allocatable arrays (ASR, LLVM)

  • Associate block (ASR, LLVM)

  • Runtime library refactoring (ASR, LLVM)

    • Split into builtin, pure and impure

    • iso_fortran_env, iso_c_binding intrinsic modules added

  • Compile time evaluation (ASR, LLVM)

Commits (git shortlog -ns v0.11.0..v0.12.0):

   369  Ondřej Čertík
    85  Thirumalai Shaktivel
    79  Gagandeep Singh
    75  Rohit Goswami
    20  Andrew Best
     4  Dominic Poerio

Updates in master since the last release:

  • LFortran can now compile binaries on Windows

  • C interoperation works on all platforms (including Windows and MSVC)

  • Runtime library improvements

    • Complex intrinsics fixed on all platforms

    • All trigonometric functions now use the Fortran impure interface in the runtime library

    • More intrinsics implemented

  • Initial implementation of classes and methods

  • LFortran now works with fpm and compiles the hello world project and a few other example projects

  • Parser improvements: team and sync statements

  • Improved handling of character types as function arguments and return values

We are looking for new contributors, so if you are interested, please get in touch with us! We would be happy to do a video call with you to get you started.


  • We had our 15th Fortran Monthly call on August 17. You can watch the recording below:

  • FortranCon 2021 will be held virtually from September 23-24, 2021. Registration is free of charge and is due by September 15. The second call for abstracts is due September 1. For more information, visit the FortranCon website.

  • Our Google Summer of Code program for 2021 is coming to a close. Read about our students and their progress so far on Discourse:

As usual, subscribe to the mailing list and/or join the Discourse to stay tuned with the future meetings.


We thank everybody who contributed to fortran-lang in the past month by commenting in any of these repositories: