Kareem Ergawy 0e93dbc6b1
[flang] do concurrent: Enable delayed localization by default (#154303)
Enables delayed localization by default for `do concurrent`. Tested both
gfortran and Fujitsu test suites.

All tests pass for gfortran tests. For Fujitsu, enabled delayed
localization passes more tests:

Delayed localization disabled:
Testing Time: 7251.76s
  Passed            : 88520
  Failed            :   162
  Executable Missing:   408

Delayed localization enabled:
Testing Time: 7216.73s
  Passed            : 88522
  Failed            :   160
  Executable Missing:   408
2025-08-19 12:07:17 +02:00
..

Flang

Flang is a ground-up implementation of a Fortran front end written in modern C++. It started off as the f18 project (https://github.com/flang-compiler/f18) with an aim to replace the previous flang project (https://github.com/flang-compiler/flang) and address its various deficiencies. F18 was subsequently accepted into the LLVM project and rechristened as Flang.

Please note that flang is not ready yet for production usage.

Getting Started

Read more about flang in the docs directory. Start with the compiler overview.

To better understand Fortran as a language and the specific grammar accepted by flang, read Fortran For C Programmers and flang's specifications of the Fortran grammar and the OpenMP grammar.

Treatment of language extensions is covered in this document.

To understand the compilers handling of intrinsics, see the discussion of intrinsics.

To understand how a flang program communicates with libraries at runtime, see the discussion of runtime descriptors.

If you're interested in contributing to the compiler, read the style guide and also review how flang uses modern C++ features.

If you are interested in writing new documentation, follow LLVM's Markdown style guide.

Consult the Getting Started with Flang for information on building and running flang.