| commit | 5c2323cfc397928b17aff9abf3f35118290f8eea | [log] [tgz] |
|---|---|---|
| author | Pete Steinfeld <47540744+psteinfeld@users.noreply.github.com> | Mon Feb 26 14:29:49 2024 -0800 |
| committer | Copybara-Service <copybara-worker@google.com> | Mon Feb 26 14:34:58 2024 -0800 |
| tree | 6f379bf8a97dc6453dd5d85468f7ba0037ee1ff5 | |
| parent | 4ed90882e322a448be1f520d02f944bf23ff0106 [diff] |
[flang] Fix ISO_Fortran_binding.h to work better with C++ code (#82556) [flang] Fix ISO_Fortran_binding.h to work better with C++ code This stems from working on LANL's "dopey" project -- https://github.com/lanl/dopey. That project contains C++ code which includes the header file "ISO_Fortran_binding.h". The dopey code wraps that include with an 'extern "C"' clause since the standard (18.5.1, paragraph 1) says that the file" shall contain C structure definitions, typedef declarations, ...". But the clang++ compiler emits error messages objecting to the fact that ISO_Fortran_binding.h contains templates. This change fixes that by preceding the problematic code in ISO_Fortran_binding.h with language linkage clauses that specify that they contain C++ code rather than C code. In the accompanying test, I needed to account for the fact that some people build the compiler by doing a `make check-flang`. In this case, the clang compiler which is required by the test will not be built. Here's an example of a C++ program that shows the problem: ``` extern "C" { #include "ISO_Fortran_binding.h" } int main() { return 0; } ``` GitOrigin-RevId: 796d26a37d70374e41766df659700a826dc62e34
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.
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.