Add --skip-clean flag

builder.py

@@ -46,7 +46,8 @@ def main():
                 args.swift_branch,
                 args.sandbox_profile_xcodebuild,
                 args.sandbox_profile_package,
-                args.add_swift_flags
+                args.add_swift_flags,
+                args.skip_clean
             ),
         ),
         index

common.py

@@ -336,6 +336,7 @@ def git_clone(url, path, tree=None, recursive=True,
     returncodes.append(check_execute(command, stdout=stdout, stderr=stderr))
     if tree:
         returncodes.append(git_checkout(tree, path,
+                                        force=True,
                                         stdout=stdout, stderr=stderr))
     if recursive:
         returncodes.append(git_submodule_update(path,
@@ -359,10 +360,12 @@ def git_sha(path, stdout=sys.stdout, stderr=sys.stderr):
 
 
 def git_update(url, configured_sha, path,
+               incremental=False,
                stdout=sys.stdout, stderr=sys.stderr):
     """Update a repository to a given sha if necessary."""
     returncodes = []
-    git_clean(path, stdout=stdout, stderr=stderr)
+    if not incremental:
+        git_clean(path, stdout=stdout, stderr=stderr)
     current_sha = git_sha(path, stdout=stdout, stderr=stderr)
     debug_print('current_sha: ' + current_sha, stderr=stderr)
     debug_print('configured_sha: ' + configured_sha, stderr=stderr)
@@ -373,6 +376,7 @@ def git_update(url, configured_sha, path,
                                          stdout=stdout, stderr=stderr))
         try:
             returncodes.append(git_checkout(configured_sha, path,
+                                            force=True,
                                             stdout=stdout, stderr=stderr))
             returncodes.append(git_submodule_update(
                 path, stdout=stdout, stderr=stderr

project.py

@@ -439,6 +439,10 @@ def add_arguments(parser):
                         metavar="FLAGS",
                         help='add flags to each Swift invocation',
                         default='')
+    parser.add_argument("--skip-clean",
+                        help='skip all git and build clean steps before '
+                             'building projects',
+                        action='store_true')
 
 
 def add_minimal_arguments(parser):
@@ -740,6 +744,7 @@ def __init__(self, swiftc, swift_version, swift_branch,
                  sandbox_profile_xcodebuild,
                  sandbox_profile_package,
                  added_swift_flags,
+                 skip_clean,
                  project, action):
         self.swiftc = swiftc
         self.swift_version = swift_version
@@ -752,6 +757,7 @@ def __init__(self, swiftc, swift_version, swift_branch,
         self.root_path = common.private_workspace('project_cache')
         self.current_platform = platform.system()
         self.added_swift_flags = added_swift_flags
+        self.skip_clean = skip_clean
         self.init()
 
     def init(self):
@@ -781,10 +787,13 @@ def checkout(self, ref, ref_is_sha, pull_after_update,
             if os.path.exists(path):
                 if ref_is_sha:
                     common.git_update(self.project['url'], ref, path,
+                                      incremental=self.skip_clean,
                                       stdout=stdout, stderr=stderr)
                 else:
-                    common.git_clean(path, stdout=stdout, stderr=stderr)
+                    if not self.skip_clean:
+                        common.git_clean(path, stdout=stdout, stderr=stderr)
                     common.git_checkout(ref, path,
+                                        force=True,
                                         stdout=stdout, stderr=stderr)
                 if pull_after_update:
                     common.git_pull(path, stdout=stdout, stderr=stderr)
@@ -803,6 +812,7 @@ def dispatch(self, identifier, stdout=sys.stdout, stderr=sys.stderr):
                      self.sandbox_profile_xcodebuild,
                      self.sandbox_profile_package,
                      self.added_swift_flags,
+                     incremental=self.skip_clean,
                      stdout=stdout, stderr=stderr)
         except common.ExecuteCommandFailure as error:
             return self.failed(identifier, error)
@@ -840,6 +850,7 @@ def dispatch(self, identifier, stdout=sys.stdout, stderr=sys.stderr):
                      self.sandbox_profile_xcodebuild,
                      self.sandbox_profile_package,
                      self.added_swift_flags,
+                     incremental=self.skip_clean,
                      should_strip_resource_phases=True,
                      stdout=stdout, stderr=stderr)
         except common.ExecuteCommandFailure as error:

runner.py

@@ -47,6 +47,7 @@ def main():
                 args.sandbox_profile_xcodebuild,
                 args.sandbox_profile_package,
                 args.add_swift_flags,
+                args.skip_clean
             ),
         ),
         index