Improve CLI interface of C++ enums to Java generator

Improve CLI interface of C++ enums to Java generator

1. Print error if input file doesn't have any annotated enums.

2. Convert "mandatory option" 'output_dir' into a positional argument.

3. Fix 'print_output_only' when running from command line.

BUG=458562
Committed: https://crrev.com/4e3301c82c48ac22439d1b9dc34ba05a0599e3e9
Cr-Commit-Position: refs/heads/master@{#317783}

[mnaganov (inactive), 2015-02-17 18:07:22]

mnaganov@chromium.org changed reviewers:
+ cjhopman@chromium.org

[mnaganov (inactive), 2015-02-17 18:07:23]

Hi Chris,

Hope you don't mind doing a review. Marcin has left the company.

I tried using the generator for the first time, and was in a gross confusion
until I figured out how it actually works. So I've made some improvements to its
CLI that would have helped me greatly, were they already in place.

[cjhopman, 2015-02-17 21:38:25]

https://codereview.chromium.org/934873002/diff/20001/build/android/gyp/java_c...
File build/android/gyp/java_cpp_enum.py (right):

https://codereview.chromium.org/934873002/diff/20001/build/android/gyp/java_c...
build/android/gyp/java_cpp_enum.py:231: def DoGenerate(options,
output_dir_and_source_paths):
extracting out bits of the list like this is odd, can we do:
def DoGenerate(options, output_dir, source_paths):

https://codereview.chromium.org/934873002/diff/20001/build/android/gyp/java_c...
build/android/gyp/java_cpp_enum.py:247: if not options.print_output_only:
We could totally get rid of the options argument here if we just passed this
flag explicitly as well.

https://codereview.chromium.org/934873002/diff/20001/build/android/gyp/java_c...
build/android/gyp/java_cpp_enum.py:331: print DoMain(sys.argv[1:])
We try to limit the output in a normal build, so I'd avoid printing this. If
this information is useful for debugging we could do something like a --verbose
flag (or a --quiet flag used in the build) and print more information.

https://codereview.chromium.org/934873002/diff/20001/build/config/android/rul...
File build/config/android/rules.gni (right):

https://codereview.chromium.org/934873002/diff/20001/build/config/android/rul...
build/config/android/rules.gni:361: args += rebase_path(gen_dir, root_build_dir)
gen_dir is a string (invoker.sources below is a list).

This should be:
args += [rebase_path(gen_dir, root_build_dir)]

or to look like the one below it:
args += rebase_path([gen_dir], root_build_dir)

[mnaganov (inactive), 2015-02-23 11:35:26]

https://codereview.chromium.org/934873002/diff/20001/build/android/gyp/java_c...
File build/android/gyp/java_cpp_enum.py (right):

https://codereview.chromium.org/934873002/diff/20001/build/android/gyp/java_c...
build/android/gyp/java_cpp_enum.py:231: def DoGenerate(options,
output_dir_and_source_paths):
On 2015/02/17 21:38:25, cjhopman wrote:
> extracting out bits of the list like this is odd, can we do:
> def DoGenerate(options, output_dir, source_paths):

Done.

https://codereview.chromium.org/934873002/diff/20001/build/android/gyp/java_c...
build/android/gyp/java_cpp_enum.py:247: if not options.print_output_only:
On 2015/02/17 21:38:25, cjhopman wrote:
> We could totally get rid of the options argument here if we just passed this
> flag explicitly as well.

Done.

https://codereview.chromium.org/934873002/diff/20001/build/android/gyp/java_c...
build/android/gyp/java_cpp_enum.py:331: print DoMain(sys.argv[1:])
On 2015/02/17 21:38:25, cjhopman wrote:
> We try to limit the output in a normal build, so I'd avoid printing this. If
> this information is useful for debugging we could do something like a
--verbose
> flag (or a --quiet flag used in the build) and print more information.

I see. Added a flag then.

https://codereview.chromium.org/934873002/diff/20001/build/config/android/rul...
File build/config/android/rules.gni (right):

https://codereview.chromium.org/934873002/diff/20001/build/config/android/rul...
build/config/android/rules.gni:361: args += rebase_path(gen_dir, root_build_dir)
On 2015/02/17 21:38:25, cjhopman wrote:
> gen_dir is a string (invoker.sources below is a list).
> 
> This should be:
> args += [rebase_path(gen_dir, root_build_dir)]
> 
> or to look like the one below it:
> args += rebase_path([gen_dir], root_build_dir)

I was supposing that gn can handle coercion itself. Fixed.

[cjhopman, 2015-02-23 19:14:38]

lgtm

[mnaganov (inactive), 2015-02-24 10:41:48]

The CQ bit was checked by mnaganov@chromium.org

[commit-bot: I haz the power, 2015-02-24 10:42:34]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/934873002/40001

[commit-bot: I haz the power, 2015-02-24 11:56:35]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-02-24 11:57:07]

Patchset 3 (id:??) landed as
https://crrev.com/4e3301c82c48ac22439d1b9dc34ba05a0599e3e9
Cr-Commit-Position: refs/heads/master@{#317783}