Working on MSVC support

[jibsen]

As discussed in #86.

The goal so far is just to get it to compile and run, here are some notes:

• Most of the plugins included strings.h, but only zpaq appeared to use it. I removed it, and added a define to zpaq to use the equivalent MSVC function.
• I put defines to map functions from strings.h to MSVC functions into internal.h
• MSVC does not come with getopt, I don't know if you would prefer to include a getopt port, or write your own command line handling. For starters I used a getopt-like parser I wrote a while back called parg.
• The following plugins did not compile out of the box: gipfeli, brotli, density, pithy, snappy, zling, and zstd.

[nemequ]

MSVC does not come with getopt, I don't know if you would prefer to include a getopt port, or write your own command line handling. For starters I used a getopt-like parser I wrote a while back called parg.

I like parg. The only reason I didn't use any long options is portability, but parg solves that issue nicely. I'll probably modify the CLI to take advantage of that soon.

The following plugins did not compile out of the box: gipfeli, brotli, density, pithy, snappy, zling, and zstd.

For gipfeli nemequ/gipfeli@26c15a2 might fix it. I've already filed a PR for that.

For zstd, I just updated the zstd submodule to the latest version, so you may want to rebase. The changes are pretty significant…

[jibsen]

I like parg. The only reason I didn't use any long options is portability, but parg solves that issue nicely. I'll probably modify the CLI to take advantage of that soon.

Okay, there is some documentation of the differences compared to getopt in the readme at https://github.com/jibsen/parg

For gipfeli nemequ/gipfeli@26c15a2 might fix it. I've already filed a PR for that.

I had that as well, but there are a couple more changes needed:

• The two defines in config.h need to be undefined (they did not even put a guard around them to check if the build system sets them).
• std::min and std::max are in the algorithm header, so entropy.cc and sinksource.h need to include it.

For zstd, I just updated the zstd submodule to the latest version, so you may want to rebase. The changes are pretty significant…

It looks like I rebased after you pulled in zstd 0.2.0, it is compiling fine here now.

[nemequ]

The two defines in config.h need to be undefined (they did not even put a guard around them to check if the build system sets them).

It would probably be better to do something like

#if defined(__GNUC__)
#  if !defined(HAVE_BUILTIN_CTZ)
#    #define HAVE_BUILTIN_CTZ
#  endif
#  if !defined(HAVE_BUILTIN_EXPECT)
#    #define HAVE_BUILTIN_EXPECT
#  endif
#endif

That would allow it to continue using those builtins on gcc and clang by default, and allow for a check in the build system for other compilers.

FWIW the Windows equivalent of __builtin_ctz is _BitScanForward/_BitScanForward64. AFAIK there is nothing like __builtin_expect.

[jibsen]

I noticed AppVeyor was up, so I am playing around with it, hope that's okay.

I think it should work, except it's missing Ragel.

[travisdowns]

What's the current status of windows support? Does this repo have all of @jibsen's updates to support windows? I'm usually developing on Linux but at the moment I'm traveling without access to a Linux box and am definitely willing to help get the Windows side of things working.

[nemequ]

What's the current status of windows support?

@jibsen is in a better position to answer this, but other than a few plugins which will not work with MSVC (see #145) AFAIK MSVC support works pretty well. Other compilers are a bit harder to judge since we don't have an AppVeyor build, but I think GCC should work, clang still has some issues.

Does this repo have all of @jibsen's updates to support windows?

Yes.

I'm usually developing on Linux but at the moment I'm traveling without access to a Linux box and am definitely willing to help get the Windows side of things working.

I'll definitely take all the help I can get. The windows label lists some relevant tasks. If you have any questions please don't hesitate to ask (here, #squash on freenode, mailing list… whatever you prefer).

[nemequ]

Sorry, I broke the MSVC build when I got Squash working on Solaris and didn't notice. It should be fixed now.

[jibsen]

I believe status on Windows is:

• with plain mingw-w64 or MSYS2 (both GCC 5.3.0) all plugins build and the unit tests run
• with MSVC 2015 all plugins except density and gipfeli build, and the unit tests run
• with Clang the situation is a little more complex, see Add clang to AppVeyor #185

I haven't tried any other compilers on Windows.

As @nemequ says, any help is greatly appreciated.