Windows support about bloaty

[haberman]

I would love to have Windows support, both for building/running on Windows and for analyzing Windows executables.

I'd be happy to take patches to make Bloaty compile on Cygwin and/or MSVC, and any bugfixes for those platforms. I'd also be happy to take patches that enable automated Windows testing on AppVeyor.

I would be curious to know why Cygwin requires -gnu++11 instead of c++11.

[parbo]

@andrew-donnell I solved it by building bloaty in Ubuntu in WSL instead.

[learn-more]

In that case the first step (imo) would be to add CMake support,
so that we do not have to use cygwin to build on windows.

(I am suggesting CMake because both dependencies support that).

After that:

• Edit the CMake configuration so that it works for windows (msvc)
• Make it build for windows (msvc)
• Setup AppVeyor builds

bloaty needs gnu++11 because otherwise __bswap_32 (and 16, 64) are not defined.
re2 needs it for the RW locks.

[haberman]

Sounds good. I don't know anything about CMake, but all of that sounds great and patches are welcome!

I think I would prefer to keep the existing Makefile also, so that CMake is not a hard dependency on Linux / OS X.

[learn-more]

After looking into it some more:

Creating a (working) cmake configuration for windows/msvc is fairly simple, but then some problems with some of the design choices present themselves:

• Minimum version is visual studio 2015 (because of constexpr)
• c++filt does not exist on windows, so that mechanism wont fly.
• Without cygwin, the fork / pipe kinda functions are not going to work on windows.

For the demangling, maybe __cxa_demangle could be used? (and preferably as library, so that windows can use it as well!)

One minor issue:
msvc is choking on the construction from BuildActionBuf:
syntax error: identifier 'IndexSequence<,unsigned int, ?? >' src\dwarf.cc:1353

[haberman]

Thanks for looking into it!

• How many people have VS2015? It is unreasonable to require VS2015?
• How many changes are required to support an earlier version of VS? I don't think there is anywhere that constexpr is integral to the design of Bloaty.
• Yes definitely we'd need some other way of demangling on Windows. It looks like there is a UnDecorateSymbolName() function available.
• Even on Linux it would be nice to link in the demangler instead of shelling out. I bet we could extract the demangling code from LLVM llvm/lib/Demangle/ItaniumDemangle.cpp to avoid shelling out to c++filt.
• fork/pipe are only necessary if we're shelling out, but if we have native file readers on for both files and symbols, that shouldn't be a problem.

Hmm, it's hard to know what MVSC is complaining about in BuildActionBuf. I have a virtual machine with Windows installed but I'm having troubles using the community edition of MSVC.

[learn-more]

• VS2015 is not unreasonable, however I do not have that at home.
• VS2013 should be reasonable to support, constexpr should be removed and it looks like some vararg template constructions are not entirely supported.
• UnDecorateSymbolName is an option on windows, however it will only demangle MSVC symbols.

I have cloned your repository, added the initial cmake + appveyor stuff in it, and gave you push access (so that you can test stuff).

[Phyllostachys]

If it adds anything to this conversation, I was able to get everything to build in msys2 + mingw-w64, besides needing to define WEXITED. I need to do some more to see if it actually works and I'm not really sure why I was expecting it to run on PE files (duh, on my part). It does work pretty nicely on my ARM elf files though.

[learn-more]

This might be a better first step then!

Initially I tried with cygwin because I did not know that msys2 has support for popen and that kinda stuff,
but the cygwin builds crashed when testing it.
That is why I moved on to trying msvc.

@Phyllostachys : Are the cmake files in https://github.com/learn-more/bloaty needed at all to get this working? (I assume not)

[Phyllostachys]

Correct, I didn't use any cmake files, just the makefile that comes with the repo. I think I found this issue after that fact or else I would have tried those too.

[skochinsky]

In case someone needs a bloaty-like tool for MSVC-compiled binary right now, I can recommend SymbolSort. It works on .obj files (via dumpbin) or compiled binaries with PDB symbols.

[parbo]

I'd like to be able to use bloaty to analyze android elf binaries on Windows. I'm getting these errors: Command line error D8004: '/W' requires an argument

[andrew-donnell]

Any tips on building on Windows? I used cygwin to clone, but I'm running into issues building in MSVS. I keep getting:
Error D8004: '/W' requires an argument or
Error D8021: 'invalid numeric argument '/Wno-sign-compare'.

[andrew-donnell]

I'd like to be able to use bloaty to analyze android elf binaries on Windows. I'm getting these errors: Command line error D8004: '/W' requires an argument

@parbo I had the same issue. I was able to resolve in VS by going into properties and adding an argument (could also be done by modifying the cmake .txt file) but then I ran into the Error D8021: 'invalid numeric argument '/Wno-sign-compare' issue. When I took that out, all hell broke loose 😝

[learn-more]

@haberman this is solved now