bbb7f01481
Ensure volatility is reflected not just on the reference to an allocatable, but on the box, too. When we declare a volatile allocatable, we now get a volatile reference to a volatile box. Some related cleanups: * SELECT TYPE constructs check the selector's type for volatility when creating and designating the type used in the selecting block. * Refine the verifier for fir.convert. In general, I think it is ok to implicitly drop volatility in any ptr-to-int conversion because it means we are in codegen (and representing volatility on the LLVM ops and intrinsics) or we are calling an external function (are there any cases I'm not thinking of?) * An allocatable test that was XFAILed is now passing. Making allocatables' boxes volatile resulted in accesses of those boxes being volatile, which resolved some errors coming from the strict verifier. * I noticed a runtime function was missing the fir.runtime attribute.
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.