Add build guards for all Windows imports

[uhthomas]

Fixes #190

[ghost]

All CLA requirements met.

[uhthomas]

Note to maintainers: Should build guards be added to all files, regardless of imports? This repository is Windows specific, so it might make sense?

[thaJeztah]

Thanks! I just opened a similar PR before noticing there was one already (closed it now: #193)

Do you think it's worth to consider adding a doc.go in each of these packages, so that they're not empty on "non-windows"? I'm not 100% sure how go mod (and go mod vendor) handles these when vendoring code and the package is "empty" on the platform on which you're executing the go mod vendor.

[thaJeztah]

@kevpar @dcantah ptal

[katiewasnothere]

Do you think it's worth to consider adding a doc.go in each of these packages, so that they're not empty on "non-windows"? I'm not 100% sure how go mod (and go mod vendor) handles these when vendoring code and the package is "empty" on the platform on which you're executing the go mod vendor.

I'm not super sure how they're handled either. If the absence of doc.go causes import errors though I think it's fine to include them to avoid that.

Note to maintainers: Should build guards be added to all files, regardless of imports? This repository is Windows specific, so it might make sense?

I think that's fine as well, especially since it makes any user errors more understandable.

[uhthomas]

@katiewasnothere re: build guards for all files; I initially like the idea, but it seems odd to constrain files which have no platform-specific requirements. I'll leave it as is for now (protect windows imports).

[kevpar]

LGTM

[uhthomas]

Hmm, looks like I might actually be missing a few build guards. Give me a moment.

[uhthomas]

Okay, had to go through and add a bunch of build tags to files which implicitly use Windows-specific code (i.e tests).

Go test seems happy

➜  go-winio git:(master) go test ./...
?       github.com/Microsoft/go-winio   [no test files]
?       github.com/Microsoft/go-winio/backuptar [no test files]
?       github.com/Microsoft/go-winio/pkg/etw   [no test files]
?       github.com/Microsoft/go-winio/wim/lzx   [no test files]

But Bazel does not

➜  wtest git:(master) ✗ bazel test @local_go_winio//...
Starting local Bazel server and connecting to it...
INFO: Analyzed 23 targets (88 packages loaded, 7439 targets configured).
INFO: Found 17 targets and 6 test targets...
ERROR: /home/thomas/.cache/bazel/_bazel_thomas/48d13cdd56897dee270c57999076ee09/external/local_go_winio/tools/etw-provider-gen/BUILD.bazel:16:10: GoLink external/local_go_winio/tools/etw-provider-gen/etw-provider-gen_/etw-provider-gen failed: (Exit 1): builder failed: error executing command bazel-out/host/bin/external/go_sdk/builder link -sdk external/go_sdk -installsuffix linux_amd64 -package_list bazel-out/host/bin/external/go_sdk/packages.txt -o ... (remaining 11 argument(s) skipped)

Use --sandbox_debug to see verbose messages from the sandbox builder failed: error executing command bazel-out/host/bin/external/go_sdk/builder link -sdk external/go_sdk -installsuffix linux_amd64 -package_list bazel-out/host/bin/external/go_sdk/packages.txt -o ... (remaining 11 argument(s) skipped)

Use --sandbox_debug to see verbose messages from the sandbox
external/go_sdk/pkg/tool/linux_amd64/link: bazel-out/k8-fastbuild/bin/external/local_go_winio/tools/etw-provider-gen/etw-provider-gen.a: not package main
link: error running subcommand external/go_sdk/pkg/tool/linux_amd64/link: exit status 2
INFO: Elapsed time: 9.307s, Critical Path: 1.48s
INFO: 96 processes: 26 internal, 70 linux-sandbox.
FAILED: Build did NOT complete successfully
@local_go_winio//:go-winio_test                                       NO STATUS
@local_go_winio//backuptar:backuptar_test                             NO STATUS
@local_go_winio//pkg/etw:etw_test                                     NO STATUS
@local_go_winio//pkg/etwlogrus:etwlogrus_test                         NO STATUS
@local_go_winio//pkg/guid:guid_test                                   NO STATUS
@local_go_winio//pkg/security:security_test                           NO STATUS

FAILED: Build did NOT complete successfully

Looks like it's complaining about there being main packages where there shouldn't. I guess this is up to the reviewer's discretion as to what to do here?

[uhthomas]

Bazel is now happy following the addition of noop mains for non Windows builds.

➜  wtest git:(master) ✗ bazel test @local_go_winio//...
INFO: Analyzed 23 targets (0 packages loaded, 0 targets configured).
INFO: Found 17 targets and 6 test targets...
INFO: Elapsed time: 0.475s, Critical Path: 0.34s
INFO: 24 processes: 1 internal, 23 linux-sandbox.
INFO: Build completed successfully, 24 total actions
@local_go_winio//:go-winio_test                                          PASSED in 0.0s
@local_go_winio//backuptar:backuptar_test                                PASSED in 0.0s
@local_go_winio//pkg/etw:etw_test                                        PASSED in 0.0s
@local_go_winio//pkg/etwlogrus:etwlogrus_test                            PASSED in 0.0s
@local_go_winio//pkg/guid:guid_test                                      PASSED in 0.0s
@local_go_winio//pkg/security:security_test                              PASSED in 0.0s

Executed 6 out of 6 tests: 6 tests pass.
There were tests whose specified size is too big. Use the --test_verbose_timeout_warnings command line option to see which ones INFO: Build completed successfully, 24 total actions

and just to double check, so is Go test.

➜  go-winio git:(master) go test ./...
?       github.com/Microsoft/go-winio   [no test files]
?       github.com/Microsoft/go-winio/backuptar [no test files]
?       github.com/Microsoft/go-winio/pkg/etw   [no test files]
?       github.com/Microsoft/go-winio/pkg/etw/sample    [no test files]
?       github.com/Microsoft/go-winio/tools/etw-provider-gen    [no test files]
?       github.com/Microsoft/go-winio/wim/lzx   [no test files]
?       github.com/Microsoft/go-winio/wim/validate      [no test files]

Do these changes look okay to you?

[katiewasnothere]

LGTM