Re: [dpdk-dev] Compiler for Windows

["Wiles, Keith" <keith.wiles@intel.com>]

Sorry I have to top post. I had surgery on my shoulder so I’m doing this from my phone. 

Why does the windows Eal directory have to be a stub? 

Normally the port must use a separate directory for different architecture. In this case it is the windows architecture which should have all of the changes required for windows and not modify Linux or BSD. 

Sent from my iPhone

> On Jan 30, 2019, at 10:32 AM, Menon, Ranjit <ranjit.menon@intel.com> wrote:
> 
> Thank you for the direction, Thomas and Tech Board members.
> 
> If clang-win64 has support for GCC extensions (__attribute(constructor/align/etc...)), then the changes to common DPDK code should be minimal. Also, Jeff got meson to output VS project files to compile with MSVC - we'll just need to make sure that they can compile with clang-win64. Thanks, Bruce for helping us out here.
> 
> ranjit m.
> 
> -----Original Message-----
> From: Thomas Monjalon <thomas@monjalon.net> 
> Sent: Wednesday, January 30, 2019 6:21 AM
> To: 'Jason Messer' <jmesser@microsoft.com>; 'Harini Ramakrishnan' <harini.ramakrishnan@microsoft.com>; 'Omar Cardona' <ocardona@microsoft.com>; Menon, Ranjit <ranjit.menon@intel.com>
> Cc: dev@dpdk.org; Burakov, Anatoly <anatoly.burakov@intel.com>; Richardson, Bruce <bruce.richardson@intel.com>; Stephen Hemminger <stephen@networkplumber.org>; 'Mattias Rönnblom' <mattias.ronnblom@ericsson.com>; Shaw, Jeffrey B <jeffrey.b.shaw@intel.com>; techboard@dpdk.org
> Subject: Re: [dpdk-dev] Compiler for Windows
> 
> 08/01/2019 11:24, Burakov, Anatoly:
>>> On 07-Jan-19 5:08 PM, Thomas Monjalon wrote:
>>> 07/01/2019 18:00, Bruce Richardson:
>>>> I think for windows we probably want to start with the MS compiler 
>>>> first, since from my understanding it's probably the default go-to 
>>>> compiler for developers on windows, and look at alternatives from there.
>>> 
>>> Not sure. I feel clang is a better option.
>>> This is the purpose of this thread: which compiler can work with the 
>>> DPDK code base? Which modifications of code are acceptable?
>>> 
>>> Unfortunately we lost my original attempt of getting some facts.
>> 
>> i'm developing on a Windows machine, and use clang as code analyzer. 
>> so while the compiling and linking may take some effort, the bulk of 
>> it appears to be working without too much complaints from clang. it's 
>> easy to install as well - just install LLVM and you're good to go.
> 
> This discussion continued in a private thread (for no good reason).
> Let's conclude here publicly.
> 
> About the compiler,
>    - cygwin is not native -> no go
>    - mingw-w64 (latest) brings a specific DLL -> one more unknown piece
>    - icc is not free -> no go
>    - msvc supports not all C99 and GNU extensions -> difficult to support
>    - clang is now native on Windows -> best choice
>      http://releases.llvm.org/7.0.1/LLVM-7.0.1-win64.exe
> 
> About the build system,
>    - DPDK makefiles are not Windows-friendly and will be removed
>    - meson is supported on Windows and can generate VS project
>      https://github.com/mesonbuild/meson/releases/download/0.49.1/meson-0.49.1-64.msi
> 
> About the Linux/BSD code,
>    - we can use some #ifdef
>    - most of the specific code should be in EAL
>    - it must be tried to share a maximum of common code
> 
> About the steps,
>    1/ meson files must be prepared for Windows target
>    2/ EAL for Windows must be an empty stub first
>    3/ The core libraries must compile with meson+clang
>    4/ Documentation for Windows must be started
>    5/ EAL for Windows can be completed with real code
>    6/ PMDs can be tested on Windows
>    7/ Examples should compile on Windows
> 
> Please restart from a fresh 19.02 branch in the draft repository and submit the steps one by one on the mailing list.
> We need to validate the steps and approve the choices.
> If some choices are done, they must be explained in the commit logs.
> The commits must be small enough to be reviewed.
> If some issues are encountered, we'll fix them as a community.
> 
> Thanks for facilitating community adoption of Windows port.
> 
>