Bug 784841 - Part 8: Capture and save moz.build tree state; r=ted

python/mozbuild/mozbuild/backend/base.py

@@ -9,8 +9,12 @@ from abc import (
     abstractmethod,
 )
 
+import os
+import sys
+
 from mach.mixin.logging import LoggingMixin
 
+from ..frontend.data import SandboxDerived
 from .configenvironment import ConfigEnvironment
 
 
@@ -53,6 +57,12 @@ class BuildBackend(LoggingMixin):
         for obj in objs:
             self.consume_object(obj)
 
+        # Write out a file indicating when this backend was last generated.
+        age_file = os.path.join(self.environment.topobjdir,
+            'backend.%s.built' % self.__class__.__name__)
+        with open(age_file, 'a'):
+            os.utime(age_file, None)
+
         self.consume_finished()
 
     @abstractmethod

python/mozbuild/mozbuild/backend/recursivemake.py

@@ -36,7 +36,11 @@ class BackendMakeFile(object):
         self.fh.write(buf)
 
     def close(self):
-        self.fh.write('BACKEND_OUTPUT_FILES += %s\n' % ' '.join(self.outputs))
+        if len(self.inputs):
+            self.fh.write('BACKEND_INPUT_FILES += %s\n' % ' '.join(self.inputs))
+
+        if len(self.outputs):
+            self.fh.write('BACKEND_OUTPUT_FILES += %s\n' % ' '.join(self.outputs))
 
         self.fh.close()
 
@@ -65,6 +69,8 @@ class RecursiveMakeBackend(BuildBackend):
         backend_file = self._backend_files.get(obj.srcdir,
             BackendMakeFile(obj.srcdir, obj.objdir))
 
+        backend_file.inputs |= obj.sandbox_all_paths
+
         if isinstance(obj, DirectoryTraversal):
             self._process_directory_traversal(obj, backend_file)
 

python/mozbuild/mozbuild/frontend/data.py

@@ -34,12 +34,19 @@ class SandboxDerived(TreeMetadata):
     __slots__ = (
         'objdir',
         'relativedir',
+        'sandbox_all_paths',
+        'sandbox_path',
         'srcdir',
         'topobjdir',
         'topsrcdir',
     )
 
     def __init__(self, sandbox):
+        # Capture the files that were evaluated to build this sandbox.
+        self.sandbox_main_path = sandbox.main_path
+        self.sandbox_all_paths = sandbox.all_paths
+
+        # Basic directory state.
         self.topsrcdir = sandbox['TOPSRCDIR']
         self.topobjdir = sandbox['TOPOBJDIR']
 

python/mozbuild/mozbuild/frontend/sandbox.py

@@ -259,6 +259,8 @@ class Sandbox(object):
             builtins=builtins)
         self._locals = LocalNamespace(self._globals)
         self._execution_stack = []
+        self.main_path = None
+        self.all_paths = set()
 
     def exec_file(self, path):
         """Execute code at a path in the sandbox.
@@ -290,6 +292,11 @@ class Sandbox(object):
         """
         self._execution_stack.append(path)
 
+        if self.main_path is None:
+            self.main_path = path
+
+        self.all_paths.add(path)
+
         # We don't have to worry about bytecode generation here because we are
         # too low-level for that. However, we could add bytecode generation via
         # the marshall module if parsing performance were ever an issue.

python/mozbuild/mozbuild/test/backend/test_recursivemake.py

@@ -20,6 +20,8 @@ class TestRecursiveMakeBackend(BackendTester):
     def test_basic(self):
         """Ensure the RecursiveMakeBackend works without error."""
         env = self._consume('stub0', RecursiveMakeBackend)
+        self.assertTrue(os.path.exists(os.path.join(env.topobjdir,
+            'backend.RecursiveMakeBackend.built')))
 
     def test_output_files(self):
         """Ensure proper files are generated."""
@@ -60,7 +62,7 @@ class TestRecursiveMakeBackend(BackendTester):
 
         p = os.path.join(env.topobjdir, 'backend.mk')
 
-        lines = [l.strip() for l in open(p, 'rt').readlines()[1:-1]]
+        lines = [l.strip() for l in open(p, 'rt').readlines()[1:-2]]
         self.assertEqual(lines, [
             'DIRS := dir1',
             'PARALLEL_DIRS := dir2',

python/mozbuild/mozbuild/test/frontend/test_emitter.py

@@ -43,6 +43,8 @@ class TestEmitterBasic(unittest.TestCase):
             self.assertEqual(o.test_tool_dirs, [])
             self.assertEqual(len(o.tier_dirs), 0)
             self.assertEqual(len(o.tier_static_dirs), 0)
+            self.assertTrue(os.path.isabs(o.sandbox_main_path))
+            self.assertEqual(len(o.sandbox_all_paths), 1)
 
         reldirs = [o.relativedir for o in objs]
         self.assertEqual(reldirs, ['', 'foo', 'foo/biz', 'bar'])

python/mozbuild/mozbuild/test/frontend/test_sandbox.py

@@ -117,6 +117,8 @@ class TestSandbox(unittest.TestCase):
         sandbox.exec_source('foo = True', 'foo.py')
 
         self.assertNotIn('foo', sandbox)
+        self.assertEqual(sandbox.main_path, 'foo.py')
+        self.assertEqual(sandbox.all_paths, set(['foo.py']))
 
     def test_exec_compile_error(self):
         sandbox = self.sandbox()
@@ -126,6 +128,7 @@ class TestSandbox(unittest.TestCase):
 
         self.assertEqual(se.exception.file_stack, ['foo.py'])
         self.assertIsInstance(se.exception.exc_value, SyntaxError)
+        self.assertEqual(sandbox.main_path, 'foo.py')
 
     def test_exec_import_denied(self):
         sandbox = self.sandbox()
@@ -210,6 +213,9 @@ add_tier_dir('t1', 'bat', static=True)
         sandbox.exec_file('moz.build')
 
         self.assertEqual(sandbox['DIRS'], ['foo', 'bar'])
+        self.assertEqual(sandbox.main_path,
+            os.path.join(sandbox['TOPSRCDIR'], 'moz.build'))
+        self.assertEqual(len(sandbox.all_paths), 2)
 
     def test_include_outside_topsrcdir(self):
         sandbox = self.sandbox(data_path='include-outside-topsrcdir')