Bug 1313306 - Allow @depends(when=something) without additional dependencies. r=chmanchester

Also allow when=True/False to avoid the chicken-egg problem of using
a generic `when` to use in replacement of @depends('--help') for things
like @dependable.

--HG--
extra : rebase_source : f1571a5b904efb66a361b90f3b7e1edbaa75772e

python/mozbuild/mozbuild/configure/__init__.py

@@ -284,6 +284,10 @@ class ConfigureSandbox(dict):
         self._help_option = self.option_impl('--help',
                                              help='print this message')
         self._seen.add(self._help_option)
+
+        self._always = DependsFunction(self, lambda: True, [])
+        self._never = DependsFunction(self, lambda: False, [])
+
         if self._value_for(self._help_option):
             self._help = HelpFormatter(argv[0])
             self._help.add(self._help_option)
@@ -494,7 +498,11 @@ class ConfigureSandbox(dict):
         return arg
 
     def _normalize_when(self, when, callee_name):
-        if when is not None:
+        if when is True:
+            when = self._always
+        elif when is False:
+            when = self._never
+        elif when is not None:
             when = self._dependency(when, callee_name, 'when')
 
         if self._default_conditions:
@@ -571,9 +579,6 @@ class ConfigureSandbox(dict):
         for its execution. This different global namespace exposes a limited
         set of functions from os.path.
         '''
-        if not args:
-            raise ConfigureError('@depends needs at least one argument')
-
         for k in kwargs:
             if k != 'when':
                 raise TypeError(
@@ -582,6 +587,9 @@ class ConfigureSandbox(dict):
 
         when = self._normalize_when(kwargs.get('when'), '@depends')
 
+        if not when and not args:
+            raise ConfigureError('@depends needs at least one argument')
+
         dependencies = tuple(self._dependency(arg, '@depends') for arg in args)
 
         conditions = [

python/mozbuild/mozbuild/configure/lint.py

@@ -34,7 +34,8 @@ class LintSandbox(ConfigureSandbox):
         if isinstance(obj, CombinedDependsFunction):
             return False
         if isinstance(obj, DependsFunction):
-            if self._help_option in obj.dependencies:
+            if (self._help_option in obj.dependencies or
+                obj in (self._always, self._never)):
                 return False
             func = self._wrapped[obj.func]
             # We allow missing --help dependencies for functions that:

python/mozbuild/mozbuild/test/configure/test_checks_configure.py

@@ -405,7 +405,7 @@ class TestChecksConfigure(unittest.TestCase):
 
         with self.assertRaises(ConfigureError) as e:
             self.get_result(
-                'foo = depends("--help")(lambda h: ("a", "b"))\n'
+                'foo = depends(when=True)(lambda: ("a", "b"))\n'
                 'check_prog("FOO", ("known-a",), input=foo)'
             )
 
@@ -415,7 +415,7 @@ class TestChecksConfigure(unittest.TestCase):
 
         with self.assertRaises(ConfigureError) as e:
             self.get_result(
-                'foo = depends("--help")(lambda h: {"a": "b"})\n'
+                'foo = depends(when=True)(lambda: {"a": "b"})\n'
                 'check_prog("FOO", ("known-a",), input=foo)'
             )
 

python/mozbuild/mozbuild/test/configure/test_compile_checks.py

@@ -47,15 +47,15 @@ class BaseCompileChecks(unittest.TestCase):
         base_dir = os.path.join(topsrcdir, 'build', 'moz.configure')
 
         mock_compiler_defs = textwrap.dedent('''\
-            @depends('--help')
-            def extra_toolchain_flags(_):
+            @depends(when=True)
+            def extra_toolchain_flags():
                 return []
 
             include('%s/compilers-util.configure')
 
             @compiler_class
-            @depends('--help')
-            def c_compiler(_):
+            @depends(when=True)
+            def c_compiler():
                 return namespace(
                     flags=[],
                     type='gcc',
@@ -65,8 +65,8 @@ class BaseCompileChecks(unittest.TestCase):
                 )
 
             @compiler_class
-            @depends('--help')
-            def cxx_compiler(_):
+            @depends(when=True)
+            def cxx_compiler():
                 return namespace(
                     flags=[],
                     type='gcc',
@@ -310,8 +310,8 @@ class TestWarningChecks(BaseCompileChecks):
 
     def test_check_and_add_gcc_warning_when(self):
         cmd = textwrap.dedent('''\
-            @depends('--help')
-            def never(_):
+            @depends(when=True)
+            def never():
                 return False
             check_and_add_gcc_warning('-Wfoo', cxx_compiler, when=never)
         ''') + self.get_warnings()
@@ -325,8 +325,8 @@ class TestWarningChecks(BaseCompileChecks):
         self.assertEqual(out, '')
 
         cmd = textwrap.dedent('''\
-            @depends('--help')
-            def always(_):
+            @depends(when=True)
+            def always():
                 return True
             check_and_add_gcc_warning('-Wfoo', cxx_compiler, when=always)
         ''') + self.get_warnings()
@@ -369,8 +369,8 @@ class TestWarningChecks(BaseCompileChecks):
 
     def test_add_gcc_warning_when(self):
         cmd = textwrap.dedent('''\
-            @depends('--help')
-            def never(_):
+            @depends(when=True)
+            def never():
                 return False
             add_gcc_warning('-Wfoo', c_compiler, when=never)
         ''') + self.get_warnings()
@@ -384,8 +384,8 @@ class TestWarningChecks(BaseCompileChecks):
         self.assertEqual(out, '')
 
         cmd = textwrap.dedent('''\
-            @depends('--help')
-            def always(_):
+            @depends(when=True)
+            def always():
                 return True
             add_gcc_warning('-Wfoo', c_compiler, when=always)
         ''') + self.get_warnings()

python/mozbuild/mozbuild/test/configure/test_configure.py

@@ -430,15 +430,9 @@ class TestConfigure(unittest.TestCase):
 
     def test_set_config_when(self):
         with self.moz_configure('''
-            @depends('--help')
-            def always(_):
-                return True
-            @depends('--help')
-            def never(_):
-                return False
             option('--with-qux', help='qux')
-            set_config('FOO', 'foo', when=always)
-            set_config('BAR', 'bar', when=never)
+            set_config('FOO', 'foo', when=True)
+            set_config('BAR', 'bar', when=False)
             set_config('QUX', 'qux', when='--with-qux')
         '''):
             config = self.get_config()
@@ -485,15 +479,9 @@ class TestConfigure(unittest.TestCase):
 
     def test_set_define_when(self):
         with self.moz_configure('''
-            @depends('--help')
-            def always(_):
-                return True
-            @depends('--help')
-            def never(_):
-                return False
             option('--with-qux', help='qux')
-            set_define('FOO', 'foo', when=always)
-            set_define('BAR', 'bar', when=never)
+            set_define('FOO', 'foo', when=True)
+            set_define('BAR', 'bar', when=False)
             set_define('QUX', 'qux', when='--with-qux')
         '''):
             config = self.get_config()
@@ -761,18 +749,12 @@ class TestConfigure(unittest.TestCase):
 
     def test_option_when(self):
         with self.moz_configure('''
-            @depends('--help')
-            def always(_):
-                return True
-            @depends('--help')
-            def never(_):
-                return False
-            option('--with-foo', help='foo', when=always)
-            option('--with-bar', help='bar', when=never)
+            option('--with-foo', help='foo', when=True)
+            option('--with-bar', help='bar', when=False)
             option('--with-qux', env="QUX", help='qux', when='--with-foo')
 
-            set_config('FOO', depends('--with-foo', when=always)(lambda x: x))
-            set_config('BAR', depends('--with-bar', when=never)(lambda x: x))
+            set_config('FOO', depends('--with-foo', when=True)(lambda x: x))
+            set_config('BAR', depends('--with-bar', when=False)(lambda x: x))
             set_config('QUX', depends('--with-qux', when='--with-foo')(lambda x: x))
         '''):
             config = self.get_config()
@@ -845,10 +827,7 @@ class TestConfigure(unittest.TestCase):
             '''))
 
         with self.moz_configure('''
-            @depends('--help')
-            def always(_):
-                return True
-            option('--with-foo', help='foo', when=always)
+            option('--with-foo', help='foo', when=True)
             set_config('FOO', depends('--with-foo')(lambda x: x))
         '''):
             with self.assertRaises(ConfigureError) as e:
@@ -859,11 +838,11 @@ class TestConfigure(unittest.TestCase):
                               'options it depends on')
 
         with self.moz_configure('''
-            @depends('--help')
-            def always(_):
+            @depends(when=True)
+            def always():
                 return True
-            @depends('--help')
-            def always2(_):
+            @depends(when=True)
+            def always2():
                 return True
             option('--with-foo', help='foo', when=always)
             set_config('FOO', depends('--with-foo', when=always2)(lambda x: x))
@@ -913,17 +892,10 @@ class TestConfigure(unittest.TestCase):
     def test_include_when(self):
         with MockedOpen({
             os.path.join(test_data_path, 'moz.configure'): textwrap.dedent('''
-                @depends('--help')
-                def always(_):
-                    return True
-                @depends('--help')
-                def never(_):
-                    return False
-
                 option('--with-foo', help='foo')
 
-                include('always.configure', when=always)
-                include('never.configure', when=never)
+                include('always.configure', when=True)
+                include('never.configure', when=False)
                 include('foo.configure', when='--with-foo')
 
                 set_config('FOO', foo)
@@ -1095,28 +1067,21 @@ class TestConfigure(unittest.TestCase):
 
     def test_depends_when(self):
         with self.moz_configure('''
-            @depends('--help')
-            def always(_):
-                return True
-            @depends('--help')
-            def never(_):
-                return False
-
-            @depends('--help', when=always)
-            def foo(_):
+            @depends(when=True)
+            def foo():
                 return 'foo'
 
             set_config('FOO', foo)
 
-            @depends('--help', when=never)
-            def bar(_):
+            @depends(when=False)
+            def bar():
                 return 'bar'
 
             set_config('BAR', bar)
 
             option('--with-qux', help='qux')
-            @depends('--help', when='--with-qux')
-            def qux(_):
+            @depends(when='--with-qux')
+            def qux():
                 return 'qux'
 
             set_config('QUX', qux)