Generators relativize all arguments of action commands

What steps will reproduce the problem?
1. Create an action in an actions or rules list such as 

          'actions': [
            {
              'action_name': 'buildDoc',
              'message': 'Generating documentation from Asciidoc source',
              'inputs': [
                'abc.txt',
                'docinfo.html'
              ],
              'outputs': [ '../../doc/abc.html' ],
              'action': [
                'asciidoctor', '-b', 'html5', '-o', '<@(_outputs)', '<@(_inputs)',
              ],
            },
          ], # actions

2. Generate a project for any version of MSVS with the MSVS project file being 
output to a different directory than the location of the .gyp file.

3. Observe that the command has become something like

    asciidoctor -b ../../../../html5 -o ../../../../doc/abc.html ../../../../src/abc/abc.txt

Note that in my case the action is specified in a gypi file located at src/abc 
relative to the including gyp file and the project file goes in 
build/msvs/win/vs20XX relative to the .gyp file.

What is the expected output? What do you see instead?

What I would like to see is

    asciidoctor -b html5 -o ../../../../doc/abc.html ../../../../src/abc/abc.txt

instead of the above which causes asciidoctor to quit complaining it has no 
such backend as ../../../../html5

What version of the product are you using? On what operating system?

ToT

Please provide any additional information below.

What is happening is that the generator is relativizing all command line 
arguments, unless prefixed with -, / or $, as if they were file names.

Everything appears to work when you use the Xcode generator because that sets 
the project to run with the current directory set to the location of the .gyp 
file, which means relativization is a NOP.

Move to an MSVS project and it breaks because when the project runs the current 
directory is that containing the .vc{,x}proj file and all command arguments are 
relativized to that.

I realise it is impractical for Gyp to understand every command you might run 
and whether an argument is a file name or something else. So there needs to be 
a way for the author of the gyp file to indicate if an argument is a file name 
or not, perhaps a special prefix that will be removed from the final command.
Original issue reported on code.google.com by marksc2...@gmail.com on 7 Oct 2015 at 12:50
cminkoff / gyp

Generators relativize all arguments of action commands #498
