Patrick Simmons 304373fb6d
Fix Debug Build Using GCC 15 (#152223)
Flang currently doesn't build in debug mode on GCC 15 due to missing
dynamic libraries in some CMakeLists.txt files, and OpenMP doesn't link
in debug mode due to the atomic library pulling in libstdc++ despite an
incomplete attempt in the CMakeLists.txt to disable glibcxx assertions.
This PR fixes these issues and allows Flang and the OpenMP runtime to
build and link on GCC 15 in debug mode.

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Co-authored-by: ronlieb <ron.lieberman@amd.com>
2025-08-21 18:28:01 -04:00
..

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.