Add .find_python() method. Supersedes #777.

mesonbuild/interpreter.py

@@ -1013,11 +1013,12 @@ class ModuleHolder(InterpreterObject):
         state.target_machine = self.interpreter.builtin['target_machine'].held_object
         if self.held_object.is_snippet(method_name):
             value = fn(self.interpreter, state, args, kwargs)
+            return self.interpreter.holderify(value)
         else:
             value = fn(state, args, kwargs)
             if num_targets != len(self.interpreter.build.targets):
                 raise InterpreterException('Extension module altered internal state illegally.')
-        return self.interpreter.module_method_callback(value)
+            return self.interpreter.module_method_callback(value)
 
 class MesonMain(InterpreterObject):
     def __init__(self, build, interpreter):
@@ -1275,8 +1276,11 @@ class Interpreter(InterpreterBase):
             return DataHolder(item)
         elif isinstance(item, dependencies.InternalDependency):
             return InternalDependencyHolder(item)
+        elif isinstance(item, dependencies.ExternalProgram):
+            return ExternalProgramHolder(item)
+        elif hasattr(item, 'held_object'):
+            return item
         else:
-            print(item)
             raise InterpreterException('Module returned a value of unknown type.')
 
     def process_new_values(self, invalues):
@@ -1293,6 +1297,8 @@ class Interpreter(InterpreterBase):
                 self.build.install_scripts.append(v)
             elif isinstance(v, build.Data):
                 self.build.data.append(v)
+            elif isinstance(v, dependencies.ExternalProgram):
+                return ExternalProgramHolder(v)
             elif isinstance(v, dependencies.InternalDependency):
                 # FIXME: This is special cased and not ideal:
                 # The first source is our new VapiTarget, the rest are deps
@@ -1304,7 +1310,6 @@ class Interpreter(InterpreterBase):
 
     def module_method_callback(self, return_object):
         if not isinstance(return_object, ModuleReturnValue):
-            print(return_object)
             assert(False)
             raise InterpreterException('Bug in module, it returned an invalid object')
         invalues = return_object.new_objects

mesonbuild/modules/python3.py

@@ -12,9 +12,11 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from .. import mesonlib
+import sys
+from .. import mesonlib, dependencies
 
 from . import ExtensionModule
+from mesonbuild.modules import ModuleReturnValue
 
 class Python3Module(ExtensionModule):
     def __init__(self):
@@ -39,5 +41,9 @@ class Python3Module(ExtensionModule):
         kwargs['name_suffix'] = suffix
         return interpreter.func_shared_module(None, args, kwargs)
 
+    def find_python(self, state, args, kwargs):
+        py3 = dependencies.ExternalProgram('python3', sys.executable, silent=True)
+        return ModuleReturnValue(py3, [py3])
+
 def initialize():
     return Python3Module()

test cases/python3/1 basic/meson.build

@@ -1,6 +1,7 @@
 project('python sample', 'c')
 
-py3 = find_program('python3')
+py3_mod = import('python3')
+py3 = py3_mod.find_python()
 
 main = files('prog.py')
 

test cases/python3/1 basic/subdir/meson.build

@@ -1,5 +1,4 @@
-submain = find_program('subprog.py')
-
 test('subdir',
-  submain,
+  py3,
+  args : files('subprog.py'),
   env : 'PYTHONPATH=' + meson.source_root())

test cases/python3/2 extmodule/meson.build

@@ -4,13 +4,15 @@ project('Python extension module', 'c',
 # we must build this project the same way.
 
 py3_mod = import('python3')
+py3 = py3_mod.find_python()
 py3_dep = dependency('python3', required : false)
 
 if py3_dep.found()
   subdir('ext')
 
   test('extmod',
-    find_program('blaster.py'),
+    py3,
+    args : files('blaster.py'),
     env : ['PYTHONPATH=' + pypathdir])
 else
   error('MESON_SKIP_TEST: Python3 libraries not found, skipping test.')

test cases/python3/3 cython/libdir/meson.build

@@ -1,13 +1,3 @@
-if host_machine.system() == 'darwin'
-  # Default suffix is 'dylib' but Python does not use for extensions.
-  suffix = 'so'
-elif host_machine.system() == 'windows'
-  # On Windows the extension is pyd for some unexplainable reason.
-  suffix = 'pyd'
-else
-  suffix = []
-endif
-
 pyx_c = custom_target('storer_pyx',
   output : 'storer_pyx.c',
   input : 'storer.pyx',

test cases/python3/3 cython/meson.build

@@ -7,10 +7,12 @@ py3_dep = dependency('python3', required : false)
 if cython.found() and py3_dep.found()
   py3_dep = dependency('python3')
   py3_mod = import('python3')
+  py3 = py3_mod.find_python()
   subdir('libdir')
 
   test('cython tester',
-    find_program('cytest.py'),
+    py3,
+    args : files('cytest.py'),
     env : ['PYTHONPATH=' + pydir]
   )
 else