[flang-commits] [flang] [flang] flang manpage overhaul (PR #144948)

[Tom Eccles via flang-commits]

================
@@ -1,22 +1,61 @@
-Flang Manual Page (In Progress)
-==================================================
-
-.. note::
-    This man page is under development.
-
-For full documentation, please see the online HTML docs:
-
-https://flang.llvm.org/docs/
-
-..  
-  The placeholder text "FlangCommandLineReference" below should eventually be replaced with the actual man page contents.  
-
-----
-
-Flang Command Line Reference
-----------------------------
+flang - the Fortran compiler
+============================
+
+SYNOPSIS
+--------
+
+:program:`flang` [*options*] *filename ...*
+
+DESCRIPTION
+-----------
+
+:program:`flang` is a Fortran compiler which encompasses preprocessing, parsing,
----------------
tblah wrote:

This information about the different stages of compilation are interesting, but I imagine most users would already be familiar with compiler drivers with these features (e.g. classic flang can do all of this). I think maybe the description should start with a very short description of what the compiler supports: something like
> Flang supports all of Fortran 95 and many newer language features. Flang supports OpenMP and has some support for OpenACC and CUDA.

I have been deliberately vague here because it could be easy to forget to update this documentation when new features are added. @clementval please could you advise on rough status of OpenACC and CUDA in upstream flang?

It might also be worth giving some very rough getting started information: e.g. observing that with some exceptions we support very similar flags to gfortran and classic-flang.

I expect these two points would give the information that most Fortran programmers need to get started without them having to read much further. Maybe an example of how to compile a very simple fortran program would be beneficial too
> flang [-fopenmp] file1.f90 file2.f90 -O3 -o program

https://github.com/llvm/llvm-project/pull/144948