Any way to perform implicit linking on Windows?

[Ben Vanik]

Hello!

I can't seem to figure out how to perform implicit linking between a cc_binary dll and cc_binary exe. Is this supported and I'm just not doing it right, or something I should file a feature request for?

Docs: https://msdn.microsoft.com/en-us/library/a90k134d.aspx

As opposed to explicit linking, which is demonstrated in the bazel sample here (https://github.com/bazelbuild/bazel/tree/master/examples/windows/dll), implicit linking needs to pass the .lib generated during linking of the dll into its dependencies. Though the .lib is generated when bazel builds the dll I can't seem to find a way to get bazel to expose it or accept it in dependent rules.

In the dll example I'd expect to be able to have a hello-world-implicit.cpp that did the following:

```

#include <stdio.h>

#include <windows.h>

__declspec(dllimport) char *get_time();

__declspec(dllimport) void say_hello(char *message);

int main() {

  char *now = get_time();

  say_hello(now);

  return 0;

}

```

And a build rule like:

```

cc_binary(

    name = "hello-implicit",

    srcs = [

        "hello-world-implicit.cpp",

    ],

    deps = [":hellolib.dll"],

)

```

Building :hellolib will cause a hellolib.lib to be written to blaze-bin but I can't get at it and bazel itself is not passing it to the linking of the exe so get_time and say_hello will be unresolved.

Thoughts? Workarounds?

[Ben Vanik]

I was able to get a successful build of my project by manually copying the .lib files to the bizarre path under blaze-bin the dlls are placed in. In my case libEGL.dll was here:

```

(workspace)\bazel-bin\_solib_x64_windows\_U@com_Ugithub_Ugoogle_Uswiftshader_S_S_Cswiftshader___Uexternal_Scom_Ugithub_Ugoogle_Uswiftshader\

```

And by placing the libEGL.lib in there as well as adding the following to my linkopts it built: "-Wl,libEGL.lib"

Unfortunately this is working outside of bazel and the next time the dll is rebuilt that directory is blasted away :(

Is there a way to get the lib file to be copied as an output along with the dll?

[Dmitry Lomov]

This is not supported yet - please file a feature request to track.

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[Ben Vanik]

Done, thanks Dmitry!

https://github.com/bazelbuild/bazel/issues/3311

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