llvm-capstone/flang
Peter Klausler e468f07550
[flang] Set "undefined" NEXTREC=n variable to 0 rather than random garbage
12.10.2.17 defines that a INQUIRE statement's NEXTREC=n output value
for a unit that is not connected for direct access becomes undefined,
but the current I/O runtime can fail in a confusing manner by trying
to return uninitialized stack garbage.

Reported on Slack by Tarun Prabhu as an intermittent failure in
the gfortran regression test inquire_pre.f90.

Differential Revision: https://reviews.llvm.org/D152295
2023-06-06 11:58:01 -07:00
..
cmake/modules [flang] Refine how Clang dependencies are expressed #58663 2023-04-16 17:44:25 +00:00
docs [flang] CUDA Fortran - part 1/5: parsing 2023-05-31 09:48:59 -07:00
examples [NFC][Py Reformat] Reformat python files in the rest of the dirs 2023-05-25 11:17:05 +02:00
include [OpenMP][bbc][flang] Add _OPENMP macro definition 2023-06-05 05:00:15 -05:00
lib [flang][hlfir] Implemented addressing an element of a polymorphic array. 2023-06-06 10:26:02 -07:00
module [Flang] Map ieee_fma intrinsic to llvm.fma 2023-06-06 02:01:36 +08:00
runtime [flang] Set "undefined" NEXTREC=n variable to 0 rather than random garbage 2023-06-06 11:58:01 -07:00
test [flang][hlfir] Implemented addressing an element of a polymorphic array. 2023-06-06 10:26:02 -07:00
tools [OpenMP][bbc][flang] Add _OPENMP macro definition 2023-06-05 05:00:15 -05:00
unittests [flang] CUDA Fortran - part 5/5: statement semantics 2023-06-01 13:31:35 -07:00
.clang-format
.clang-tidy
.drone.star
.gitignore
CMakeLists.txt [flang] Fix for 541f5c4a6d (D140524) breaking out-of-tree flang build. 2023-06-03 15:19:01 +02:00
CODE_OWNERS.TXT [Flang] Add code owner for the Driver 2023-04-14 14:38:32 +00:00
LICENSE.TXT
README.md [Flang][Docs] Add a GettingStarted.md for build instructions 2023-04-12 23:33:48 +05:30

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.