win: Add and use GET_FUNCTION() and GET_FUNCTION_REQUIRED()

win: Add and use GET_FUNCTION() and GET_FUNCTION_REQUIRED()

These wrap the GetProcAddress(LoadLibrary(), …) idiom into macros that
are much less wordy.

TEST=crashpad_util_test GetFunction.GetFunction and all others
R=scottmg@chromium.org

Committed: https://chromium.googlesource.com/crashpad/crashpad/+/d075a9eb2e05359ab2555c7a0d0d9820f8b31aa4

[Mark Mentovai, 2015-10-17 02:21:00]

mark@chromium.org changed reviewers:
+ scottmg@chromium.org

[Mark Mentovai, 2015-10-17 02:21:01]

When you said my mind was in a terrible place in
https://codereview.chromium.org/1405243002/, I got the idea to try to cure it.

[scottmg, 2015-10-19 17:28:06]

Nice! LGTM.

For GetModuleHandle() vs. LoadLibrary() normally you'd use GetModuleHandle() for
the "must be loaded ones" but it's not very important, and I wasn't consistent
before anyway.

https://codereview.chromium.org/1405323003/diff/1/util/win/get_function.h
File util/win/get_function.h (right):

https://codereview.chromium.org/1405323003/diff/1/util/win/get_function.h#new...
util/win/get_function.h:67: //! \endcode
Just note here that they use ::LoadLibrary(), as it can't be used in DllMain().

[Mark Mentovai, 2015-10-19 17:35:57]

I think that the only one we might actually load is psapi.dll. Can we switch to
GetModuleHandle() if we link against psapi.lib, or is there a good reason to
avoid doing that? I’d prefer GetModuleHandle() to LoadLibrary().

[Mark Mentovai, 2015-10-19 17:58:53]

Patch set 2 uses GetModuleHandle() and -lpsapi.lib, but it doesn’t actually
work. Probably it’s because we don’t actually reference anything from psapi, so
the linker doesn’t wind up bringing it in.

[scottmg, 2015-10-19 18:05:29]

On 2015/10/19 17:58:53, Mark Mentovai wrote:
> Patch set 2 uses GetModuleHandle() and -lpsapi.lib, but it doesn’t actually
> work. Probably it’s because we don’t actually reference anything from psapi,
so
> the linker doesn’t wind up bringing it in.

Yeah, that's probably right. I think in a general utility function,
LoadLibrary() makes more sense anyway.

[Mark Mentovai, 2015-10-19 18:12:57]

Patchset #3 (id:40001) has been deleted

[Mark Mentovai, 2015-10-19 18:14:55]

Updated per feedback.

I like GetModuleHandle() better, but at this point it’s not worth
parameterizing.

[scottmg, 2015-10-19 18:19:39]

lgtm

[Mark Mentovai, 2015-10-19 18:32:13]

Committed patchset #3 (id:60001) manually as
d075a9eb2e05359ab2555c7a0d0d9820f8b31aa4 (presubmit successful).