[flang][NFC] Extract StackArrays analysis and rewrite into a header - memory passes unification [1/5] (#210721) Move InsertionPoint, StackArraysAnalysisWrapper, and AllocMemConversion out of the anonymous namespace in StackArrays.cpp into a new StackArrays.h header (in namespace fir), so the "which fir.allocmem can be safely moved to the stack, and where" analysis and the heap-to-stack rewrite pattern can be reused by other passes. The dataflow internals (AllocationState, LatticePoint, AllocationAnalysis), the command-line options, and all method definitions remain in the .cpp. No functional change intended. RFC: https://discourse.llvm.org/t/rfc-flang-improving-temporary-and-local-array-allocations-unify-stackarray-memoryallocation/91353 Assisted-by: AI GitOrigin-RevId: 9a5434468bf5a5aa77f46de98d17ec2eccdce39d
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.