gclient: Add a command to get revision/variable information.

Introduce a getdep command to get revision/version/variable value information
as a counterpart for gclient setdep.

It will be useful for autorollers.

Bug: 760633
Change-Id: Iabeae0e78c6fbdcb1a3a79cfb380ac2d83f256d5
Reviewed-on: https://chromium-review.googlesource.com/999171
Reviewed-by: Aaron Gable <agable@chromium.org>
Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>

gclient.py

@@ -2936,6 +2936,48 @@ def CMDrevinfo(parser, args):
   return 0
 
 
+def CMDgetdep(parser, args):
+  """Gets revision information and variable values from a DEPS file."""
+  parser.add_option('--var', action='append',
+                    dest='vars', metavar='VAR', default=[],
+                    help='Gets the value of a given variable.')
+  parser.add_option('-r', '--revision', action='append',
+                    dest='revisions', metavar='DEP', default=[],
+                    help='Gets the revision/version for the given dependency. '
+                         'If it is a git dependency, dep must be a path. If it '
+                         'is a CIPD dependency, dep must be of the form '
+                         'path:package.')
+  parser.add_option('--deps-file', default='DEPS',
+                    # TODO(ehmaldonado): Try to find the DEPS file pointed by
+                    # .gclient first.
+                    help='The DEPS file to be edited. Defaults to the DEPS '
+                         'file in the current directory.')
+  (options, args) = parser.parse_args(args)
+
+  if not os.path.isfile(options.deps_file):
+    raise gclient_utils.Error(
+        'DEPS file %s does not exist.' % options.deps_file)
+  with open(options.deps_file) as f:
+    contents = f.read()
+  local_scope = gclient_eval.Parse(
+      contents, expand_vars=True, validate_syntax=True,
+      filename=options.deps_file)
+
+  for var in options.vars:
+    print(gclient_eval.GetVar(local_scope, var))
+
+  for name in options.revisions:
+    if ':' in name:
+      name, _, package = name.partition(':')
+      if not name or not package:
+        parser.error(
+            'Wrong CIPD format: %s:%s should be of the form path:pkg.'
+            % (name, package))
+      print(gclient_eval.GetCIPD(local_scope, name, package))
+    else:
+      print(gclient_eval.GetRevision(local_scope, name))
+
+
 def CMDsetdep(parser, args):
   """Modifies dependency revisions and variable values in a DEPS file"""
   parser.add_option('--var', action='append',

gclient_eval.py

@@ -690,3 +690,49 @@ def SetRevision(gclient_dict, dep_name, new_revision):
     _UpdateRevision(gclient_dict['deps'][dep_name], 'url', new_revision)
   else:
     _UpdateRevision(gclient_dict['deps'], dep_name, new_revision)
+
+
+def GetVar(gclient_dict, var_name):
+  if 'vars' not in gclient_dict or var_name not in gclient_dict['vars']:
+    raise KeyError(
+        "Could not find any variable called %s." % var_name)
+
+  return gclient_dict['vars'][var_name]
+
+
+def GetCIPD(gclient_dict, dep_name, package_name):
+  if 'deps' not in gclient_dict or dep_name not in gclient_dict['deps']:
+    raise KeyError(
+        "Could not find any dependency called %s." % dep_name)
+
+  # Find the package with the given name
+  packages = [
+      package
+      for package in gclient_dict['deps'][dep_name]['packages']
+      if package['package'] == package_name
+  ]
+  if len(packages) != 1:
+    raise ValueError(
+        "There must be exactly one package with the given name (%s), "
+        "%s were found." % (package_name, len(packages)))
+
+  return packages[0]['version'][len('version:'):]
+
+
+def GetRevision(gclient_dict, dep_name):
+  if 'deps' not in gclient_dict or dep_name not in gclient_dict['deps']:
+    raise KeyError(
+        "Could not find any dependency called %s." % dep_name)
+
+  dep = gclient_dict['deps'][dep_name]
+  if dep is None:
+    return None
+  elif isinstance(dep, basestring):
+    _, _, revision = dep.partition('@')
+    return revision or None
+  elif isinstance(dep, collections.Mapping) and 'url' in dep:
+    _, _, revision = dep['url'].partition('@')
+    return revision or None
+  else:
+    raise ValueError(
+        '%s is not a valid git dependency.' % dep_name)

tests/gclient_eval_unittest.py

@@ -236,7 +236,7 @@ class EvaluateConditionTest(unittest.TestCase):
         str(cm.exception))
 
 
-class AddVarTest(unittest.TestCase):
+class VarTest(unittest.TestCase):
   def assert_adds_var(self, before, after):
     local_scope = gclient_eval.Exec('\n'.join(before))
     gclient_eval.AddVar(local_scope, 'baz', 'lemur')
@@ -276,7 +276,26 @@ class AddVarTest(unittest.TestCase):
         '}',
     ]))
 
-  def test_preserves_formatting(self):
+  def test_gets_and_sets_var(self):
+    local_scope = gclient_eval.Exec('\n'.join([
+        'vars = {',
+        '  "foo": "bar",',
+        '}',
+    ]))
+
+    result = gclient_eval.GetVar(local_scope, 'foo')
+    self.assertEqual(result, "bar")
+
+    gclient_eval.SetVar(local_scope, 'foo', 'baz')
+    result = gclient_eval.RenderDEPSFile(local_scope)
+
+    self.assertEqual(result, '\n'.join([
+        'vars = {',
+        '  "foo": "baz",',
+        '}',
+    ]))
+
+  def test_add_preserves_formatting(self):
     before = [
         '# Copyright stuff',
         '# some initial comments',
@@ -310,25 +329,7 @@ class AddVarTest(unittest.TestCase):
     ]
     self.assert_adds_var(before, after)
 
-
-class SetVarTest(unittest.TestCase):
-  def test_sets_var(self):
-    local_scope = gclient_eval.Exec('\n'.join([
-        'vars = {',
-        '  "foo": "bar",',
-        '}',
-    ]))
-
-    gclient_eval.SetVar(local_scope, 'foo', 'baz')
-    result = gclient_eval.RenderDEPSFile(local_scope)
-
-    self.assertEqual(result, '\n'.join([
-        'vars = {',
-        '  "foo": "baz",',
-        '}',
-    ]))
-
-  def test_preserves_formatting(self):
+  def test_set_preserves_formatting(self):
     local_scope = gclient_eval.Exec('\n'.join([
         'vars = {',
         '   # Comment with trailing space ',
@@ -347,8 +348,8 @@ class SetVarTest(unittest.TestCase):
     ]))
 
 
-class SetCipdTest(unittest.TestCase):
-  def test_sets_cipd(self):
+class CipdTest(unittest.TestCase):
+  def test_gets_and_sets_cipd(self):
     local_scope = gclient_eval.Exec('\n'.join([
         'deps = {',
         '    "src/cipd/package": {',
@@ -368,6 +369,10 @@ class SetCipdTest(unittest.TestCase):
         '}',
     ]))
 
+    result = gclient_eval.GetCIPD(
+        local_scope, 'src/cipd/package', 'another/cipd/package')
+    self.assertEqual(result, '5678')
+
     gclient_eval.SetCIPD(
         local_scope, 'src/cipd/package', 'another/cipd/package', '6.789')
     result = gclient_eval.RenderDEPSFile(local_scope)
@@ -392,13 +397,17 @@ class SetCipdTest(unittest.TestCase):
     ]))
 
 
-class SetRevisionTest(unittest.TestCase):
-  def assert_changes_revision(self, before, after):
+class RevisionTest(unittest.TestCase):
+  def assert_gets_and_sets_revision(self, before, after, rev_before='deadbeef'):
     local_scope = gclient_eval.Exec('\n'.join(before))
+
+    result = gclient_eval.GetRevision(local_scope, 'src/dep')
+    self.assertEqual(result, rev_before)
+
     gclient_eval.SetRevision(local_scope, 'src/dep', 'deadfeed')
     self.assertEqual('\n'.join(after), gclient_eval.RenderDEPSFile(local_scope))
 
-  def test_sets_revision(self):
+  def test_revision(self):
     before = [
         'deps = {',
         '  "src/dep": "https://example.com/dep.git@deadbeef",',
@@ -409,9 +418,9 @@ class SetRevisionTest(unittest.TestCase):
         '  "src/dep": "https://example.com/dep.git@deadfeed",',
         '}',
     ]
-    self.assert_changes_revision(before, after)
+    self.assert_gets_and_sets_revision(before, after)
 
-  def test_sets_revision_new_line(self):
+  def test_revision_new_line(self):
     before = [
         'deps = {',
         '  "src/dep": "https://example.com/dep.git@"',
@@ -424,9 +433,9 @@ class SetRevisionTest(unittest.TestCase):
         '             + "deadfeed",',
         '}',
     ]
-    self.assert_changes_revision(before, after)
+    self.assert_gets_and_sets_revision(before, after)
 
-  def test_sets_revision_inside_dict(self):
+  def test_revision_inside_dict(self):
     before = [
         'deps = {',
         '  "src/dep": {',
@@ -443,7 +452,7 @@ class SetRevisionTest(unittest.TestCase):
         '  },',
         '}',
     ]
-    self.assert_changes_revision(before, after)
+    self.assert_gets_and_sets_revision(before, after)
 
   def test_follows_var_braces(self):
     before = [
@@ -462,7 +471,7 @@ class SetRevisionTest(unittest.TestCase):
         '  "src/dep": "https://example.com/dep.git@{dep_revision}",',
         '}',
     ]
-    self.assert_changes_revision(before, after)
+    self.assert_gets_and_sets_revision(before, after)
 
   def test_follows_var_braces_newline(self):
     before = [
@@ -483,7 +492,7 @@ class SetRevisionTest(unittest.TestCase):
         '             + "@{dep_revision}",',
         '}',
     ]
-    self.assert_changes_revision(before, after)
+    self.assert_gets_and_sets_revision(before, after)
 
   def test_follows_var_function(self):
     before = [
@@ -502,7 +511,7 @@ class SetRevisionTest(unittest.TestCase):
         '  "src/dep": "https://example.com/dep.git@" + Var("dep_revision"),',
         '}',
     ]
-    self.assert_changes_revision(before, after)
+    self.assert_gets_and_sets_revision(before, after)
 
   def test_pins_revision(self):
     before = [
@@ -515,7 +524,7 @@ class SetRevisionTest(unittest.TestCase):
         '  "src/dep": "https://example.com/dep.git@deadfeed",',
         '}',
     ]
-    self.assert_changes_revision(before, after)
+    self.assert_gets_and_sets_revision(before, after, rev_before=None)
 
 
   def test_preserves_formatting(self):
@@ -545,7 +554,7 @@ class SetRevisionTest(unittest.TestCase):
         ' },',
         '}',
     ]
-    self.assert_changes_revision(before, after)
+    self.assert_gets_and_sets_revision(before, after)
 
 
 class ParseTest(unittest.TestCase):