Reuse build condition for multiple targets in binding.gyp - node-gyp

Question

Originally my binding file has only one target and that has been fine:
{
'targets': [
{
'target_name': 'target1',
'sources': [ 'source1.cc', 'source2.cc' ],
'cflags_cc!': [ '-fno-rtti', '-fno-exceptions' ],
'cflags!': [ '-fno-exceptions' ],
'conditions': [
#A very, very long condition
]
},
}
Now I need another target which is more or less the same, but build an executable file instead of link object. If I duplicate the original target, that will be OK, however I don't want to repeat the condition which is exactly the same. How could I do that?
E.g. My ideal bindin.gyp would look somewhat like this:
{
'conditions': [
#A very, very long condition
]
'targets': [
{
'target_name': 'target1',
'sources': [ 'source1.cc', 'source2.cc' ],
'cflags_cc!': [ '-fno-rtti', '-fno-exceptions' ],
'cflags!': [ '-fno-exceptions' ],
'conditions' : #Refer to the conditions stated above
},
{
'target_name': 'target2',
'type' : 'executable'
'sources': [ 'source1.cc', 'source3.cc' ],
'cflags_cc!': [ '-fno-rtti', '-fno-exceptions' ],
'cflags!': [ '-fno-exceptions' ],
'conditions' : #Refer to the conditions stated above
},
}
I tried using variables but node-gyp only allows variables of type string or list, while 'conditions' is an associative array

Answer 1

I'm not really sure, but at a guess, you might be able to stick the long condition array in a third target and depend on that condition target from each of the other two. Something like this:
{
'targets': [
{
'target_name': 'conditions_target',
'conditions': [
#A very, very long condition
]
},
{
'target_name': 'target1',
'sources': [ 'source1.cc', 'source2.cc' ],
'cflags_cc!': [ '-fno-rtti', '-fno-exceptions' ],
'cflags!': [ '-fno-exceptions' ],
'dependencies': [
'conditions_target',
],
},
{
'target_name': 'target2',
'type' : 'executable'
'sources': [ 'source1.cc', 'source3.cc' ],
'cflags_cc!': [ '-fno-rtti', '-fno-exceptions' ],
'cflags!': [ '-fno-exceptions' ],
'dependencies': [
'conditions_target',
],
},
}
But I'm not very experienced with node-gyp and that might blow things up.
More on dependencies here: https://gyp.gsrc.io/docs/UserDocumentation.md#Dependencies-between-targets

Answer 2

Thanks for suggestion from Joshua Skrzypek.
By my test, it can create a target with type 'none' for reusing build settings (including conditions, include_dirs, defines, ...) for not only other targets but also their direct or indirect dependents (using all_dependent_settings)! This is an example:
{
'targets': [
{
'target_name': 'all-settings',
'type': 'none',
'all_dependent_settings': {
'defines': [
'FOO',
],
'conditions': [
['OS=="mac"', {
'xcode_settings': {
'OTHER_LDFLAGS': [
'-undefined dynamic_lookup'
],
},
}],
['OS=="win"', {
'defines': [
'WIN32',
],
}, {
'defines': [
'OTHER',
],
}],
],
'include_dirs': [
'include',
],
'cflags': ['-Wall'],
'xcode_settings': {
'OTHER_CFLAGS': ['-Wall']
},
}
},
{
'target_name': 'mylib',
'type': 'shared_library',
'dependencies': [
'all-settings'
],
'sources': [
'foo.cc',
'bar.cc',
],
}
]
}
This method is used in my npm pacakges. See this for reference:
https://github.com/MrMYHuang/libxmljs/blob/ccbbea919e0718f45117481235e67185857c06e1/binding.gyp
and its dependent package:
https://github.com/MrMYHuang/node-libxslt/blob/49810b2269cb3c049a451bd3175eaad4d9de959c/binding.gyp#L10