llvm-project/flang
peter klausler f7be251804 [flang] Initial buffer framing code
Address review comments

Integer output data editing (I,B,O,Z)

Full integer output formatting

Stub out some work in progress

Progress on E output data editing

E, D, EN, and ES output editing done

Fw.d output editing

Real G output editing

G output editing for reals

Make environment a distinct module

CHARACTER and LOGICAL output editing

Minimal decimal representations for E0, F0, G0 editing

Move real output editing code into its own file

Fix/dodge some GCC build problems

Prep work for external I/O statement state

External HELLO, WORLD

Fix build problem with GCC

Add virtual destructors where needed

Add new test

Original-commit: flang-compiler/f18@c3f1774f8e
Reviewed-on: https://github.com/flang-compiler/f18/pull/950
2020-02-04 14:40:05 -08:00
..
documentation [flang] Explanation of how to implement a semantic check 2020-02-03 09:27:14 -08:00
include/flang [flang] Semantic checks for deallocating entities with IMPURE FINAL procedures 2020-01-29 12:42:52 -08:00
lib [flang] Initial buffer framing code 2020-02-04 14:40:05 -08:00
module [flang] Minor format change to LLVM license lines 2020-01-10 12:12:03 -08:00
runtime [flang] Initial buffer framing code 2020-02-04 14:40:05 -08:00
test [flang] Initial buffer framing code 2020-02-04 14:40:05 -08:00
test-lit [flang] Regression tests configuration for f18 repository (flang-compiler/f18#861) 2020-01-14 08:20:49 -08:00
tools [flang] Changed *.cc file extension to *.cpp (updated scripts) (flang-compiler/f18#958) 2020-01-27 18:18:45 -08:00
.clang-format [flang] Moved public headers to include/flang (flang-compiler/f18#943) 2020-01-27 12:57:59 -08:00
.drone.star [flang] Another atempt to lower core count 2019-11-18 14:27:34 +00:00
.gitignore [flang] Do not remove things from .gitignore 2019-07-23 14:57:46 -07:00
CMakeLists.txt [flang] Regression tests configuration for f18 repository (flang-compiler/f18#861) 2020-01-14 08:20:49 -08:00
LICENSE.txt [flang] Flang relicensing changes for LLVM Apache 2.0 license 2019-12-23 10:26:16 -08:00
README.md [flang] Regression tests configuration for f18 repository (flang-compiler/f18#861) 2020-01-14 08:20:49 -08:00

README.md

F18

F18 is a ground-up implementation of a Fortran front end written in modern C++. F18, when combined with LLVM, is intended to replace the Flang compiler.

Flang is a Fortran compiler targeting LLVM. Visit the Flang wiki for more information about Flang.

Getting Started

Read more about f18 in the documentation directory. Start with the compiler overview.

To better understand Fortran as a language and the specific grammar accepted by f18, read Fortran For C Programmers and f18'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 an f18 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 f18 uses modern C++ features.

Building F18

Get the Source Code

cd where/you/want/the/source
git clone https://github.com/flang-compiler/f18.git

Supported C++ compilers

F18 is written in C++17.

The code has been compiled and tested with GCC versions 7.2.0, 7.3.0, 8.1.0, and 8.2.0.

The code has been compiled and tested with clang version 7.0 and 8.0 using either GNU's libstdc++ or LLVM's libc++.

LLVM dependency

F18 uses components from LLVM.

The instructions to build LLVM can be found at https://llvm.org/docs/GettingStarted.html.

We highly recommend using the same compiler to compile both llvm and f18.

The f18 CMakeList.txt file uses the variable LLVM_DIR to find the installed components.

To get the correct LLVM libraries included in your f18 build, define LLVM_DIR on the cmake command line.

LLVM=<LLVM_INSTALLATION_DIR>/lib/cmake/llvm cmake -DLLVM_DIR=$LLVM ...

where LLVM_INSTALLATION_DIR is the top-level directory where llvm is installed.

LLVM dependency for lit Regression tests

F18 has tests that use the lit framework, these tests rely on the presence of llvm tools as llvm-lit, FileCheck, and others. These tools are installed when LLVM build set:

LLVM_INSTALL_UTILS=On

to run the regression tests on f18.

Building f18 with GCC

By default, cmake will search for g++ on your PATH. The g++ version must be one of the supported versions in order to build f18.

Or, cmake will use the variable CXX to find the C++ compiler. CXX should include the full path to the compiler or a name that will be found on your PATH, e.g. g++-7.2, assuming g++-7.2 is on your PATH.

export CXX=g++-7.2

or

CXX=/opt/gcc-7.2/bin/g++-7.2 cmake ...

There's a third option! The CMakeList.txt file uses the variable GCC as the path to the bin directory containing the C++ compiler.

GCC can be defined on the cmake command line where <GCC_DIRECTORY> is the path to a GCC installation with bin, lib, etc:

cmake -DGCC=<GCC_DIRECTORY> ...

Building f18 with clang

To build f18 with clang, cmake needs to know how to find clang++ and the GCC library and tools that were used to build clang++.

The CMakeList.txt file expects either CXX or BUILD_WITH_CLANG to be set.

CXX should include the full path to clang++ or clang++ should be found on your PATH.

export CXX=clang++

BUILD_WITH_CLANG can be defined on the cmake command line where <CLANG_DIRECTORY> is the path to a clang installation with bin, lib, etc:

cmake -DBUILD_WITH_CLANG=<CLANG_DIRECTORY>

Or GCC can be defined on the f18 cmake command line where <GCC_DIRECTORY> is the path to a GCC installation with bin, lib, etc:

cmake -DGCC=<GCC_DIRECTORY> ...

To use f18 after it is built, the environment variables PATH and LD_LIBRARY_PATH must be set to use GCC and its associated libraries.

Installation Directory

To specify a custom install location, add -DCMAKE_INSTALL_PREFIX=<INSTALL_PREFIX> to the cmake command where <INSTALL_PREFIX> is the path where f18 should be installed.

Build Types

To create a debug build, add -DCMAKE_BUILD_TYPE=Debug to the cmake command. Debug builds execute slowly.

To create a release build, add -DCMAKE_BUILD_TYPE=Release to the cmake command. Release builds execute quickly.

Build F18

cd ~/f18/build
cmake -DLLVM_DIR=$LLVM ~/f18/src
make

How to Run the Regression Tests

To run all tests:

cd ~/f18/build
cmake -DLLVM_DIR=$LLVM ~/f18/src
make check-all

To run individual regression tests llvm-lit needs to know the lit configuration for f18. The parameters in charge of this are: flang_site_config and flang_config. And they can be set as shown bellow:

<path-to-llvm-lit>/llvm-lit \
 --param flang_site_config=<path-to-f18-build>/test-lit/lit.site.cfg.py \
 --param flang_config=<path-to-f18-build>/test-lit/lit.cfg.py \
  <path-to-fortran-test>