Re: [Boost-testing] setup to test mngw- ...

Subject: Re: [Boost-testing] setup to test mngw- ...
From: Edward Diener (eldiener_at_[hidden])
Date: 2017-10-18 21:20:40

On 10/18/2017 12:21 PM, Robert Ramey via Boost-Testing wrote:
> I've been working to get out one last issue with the boost serialization 
> library related to code visibility.  It shows up on only one platform. 
> That is gcc-mngw-gnu on the boost develop test matrix.  So I conjured up 
> a windows machine and I want to run these tests locally.  I'm really 
> confused about what software I have to install in order replicate the 
> behavior on the test matrix.  If I google mngw it seems that there are 
> multiple distributions using this name.  I tried one one but I 
> downloaded the compiler first and then msys and tried to run "bootstrap" 
> but was unsuccessful.  I need some advice on how to do this.
> 
> I did manage to implement the above procedure with Cygwin which found 
> found an unrelated bug.  So I'm confident I'm on the right track.  But I 
> need help and would appreciate information from anyone who has done this.

Here is my recipe for using mingw/gcc under Windows:

1) Do not bother with mingw, just use mingw-64.
2) Go to https://sourceforge.net/projects/mingw-w64/
3) Click on the green rectangle that says
"Download mingw-w64-install.exe".
4) This should download the file to your hard drive somewhere. Put this 
file away somewhere so that you can invoke it a number of times.
5) Execute mingw-w64-install.exe,. click Next, and choose which version 
you want to install. Currently you can install any gcc version from 
4.8.1 through 7.1.0, and 32 and 64-bit versions.
6) When you install it will suggest a path, but since that path has 
spaces, I always override it to a path with no spaces. Boost Build is 
famous for problems regarding spaces in a file specification so I never 
install anything I will be using with Boost Build to a path with spaces. 
You would be wise to do the same.
7) Once installed the setup in user-config.jam will look like:

using gcc : 7.1 :

C:/Utilities/mingw-w64/i686-7.1.0-posix-dwarf-rt_v5-rev2/mingw32/bin/g++ :
     <cxxflags>-Wno-unused-local-typedefs
     <cxxflags>-ftrack-macro-expansion=0
     <cxxflags>-Wno-unused-variable
     <cxxflags>-D_GLIBCXX_USE_CXX11_ABI=1
     ;

You can pick and choose which cxxflags you want, but that is my list.

8) Now comes the difficult part which I know you are not going to like. 
Just don't curse me, but curse mingw-64/gcc instead. In order to 
compile, link, or run, the gcc bin directory must be in your Windows 
PATH; it is not good enough to execute g++ from the correct directory. 
This is a major PITA, because whenever you invoke, as above 'b2 
toolset=gcc-7.1' 
C:/Utilities/mingw-w64/i686-7.1.0-posix-dwarf-rt_v5-rev2/mingw32/bin 
better be in your PATH or else nothing will work because gcc-7.1 will 
not find what it needs.
9) Furthermore b2 used to test every toolset in user-config.jam even if 
you were not invoking that toolset via a 'b2 toolset=something". This 
meant that if you had multiple gcc toolsets in your user-config.jam for 
gcc, the b2 invocation would fail because it is impossible to have the 
bin directory for all those multiple toolsets first in your PATH at the 
same time. I believe Steve Watanabe fixed this but I am not sure.
10) So my setup, when using a version of gcc as the toolset is that I 
have a separately named user-config.jam for each gcc toolset, with names 
like user-config.gcc-7.1 etc, and then before invoking the gcc toolset I 
do a symbolic link to user-config.jam from user-config.gcc-7.1 etc and 
then I invoke 'b2 toolset=gcc-7.1 ...".
11) You can complain to mingw-64/gcc ( it is even worse with mingw/gcc, 
but almost no one uses that anymore ) about the stupidity of requiring 
the particular mingw-64 bin directory to be in the Windows PATH in order 
that the g++ command finds the libraries and include files and whatever 
else it needs in order to compile, link, or run an executable; but they 
will not care and just cite to you that VC++ sort of does the same.

That is my recipe ! If you have any questions about it please ask and I 
will try to help you mas much as I can.

> 
> Robert Ramey