Welcome to Flang's documentation

Flang is LLVM's Fortran frontend that can be found here. It is often referred to as “LLVM Flang” to differentiate itself from “Classic Flang” - these are two separate and independent Fortran compilers. LLVM Flang is under active development. While it is capable of generating executables for a number of examples, some functionality is still missing. See GettingInvolved for tips on how to get in touch with us and to learn more about the current status.

.. toctree::
   :titlesonly:

   ReleaseNotes

Contributing to Flang

.. toctree::
   :titlesonly:

   C++17
   C++style
   FortranForCProgrammers
   GettingInvolved
   GettingStarted
   ImplementingASemanticCheck
   PullRequestChecklist

Design Documents

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   :titlesonly:

   ArrayComposition
   BijectiveInternalNameUniquing
   Calls
   Character
   ControlFlowGraph
   Directives
   DoConcurrent
   Extensions
   FIRLangRef
   FlangCommandLineReference
   FlangDriver
   FortranIR
   FortranLLVMTestSuite
   IORuntimeInternals
   Intrinsics
   IntrinsicTypes
   LabelResolution
   ModFiles
   OpenMP-4.5-grammar.md
   OpenMP-semantics
   OptionComparison
   Overview
   ParserCombinators
   Parsing
   Preprocessing
   RuntimeDescriptor
   RuntimeTypeInfo
   Semantics
   f2018-grammar.md

Indices and tables

* :ref:`genindex`
* :ref:`modindex`
* :ref:`search`