Add support for creating symbolic links on Windows
Replace all calls to os.symlink with platform_utils.symlink.
The Windows implementation calls into the CreateSymbolicLinkW Win32
API, as os.symlink is not supported.
Separate the Win32 API definitions into a separate module
platform_utils_win32 for clarity.
Change-Id: I0714c598664c2df93383734e609d948692c17ec5
diff --git a/platform_utils.py b/platform_utils.py
index 1c719b1..f4dfa0b 100644
--- a/platform_utils.py
+++ b/platform_utils.py
@@ -167,3 +167,46 @@
self.queue.put(_FileDescriptorStreamsThreads.QueueItem(self, line))
self.fd.close()
self.queue.put(_FileDescriptorStreamsThreads.QueueItem(self, None))
+
+
+def symlink(source, link_name):
+ """Creates a symbolic link pointing to source named link_name.
+ Note: On Windows, source must exist on disk, as the implementation needs
+ to know whether to create a "File" or a "Directory" symbolic link.
+ """
+ if isWindows():
+ import platform_utils_win32
+ source = _validate_winpath(source)
+ link_name = _validate_winpath(link_name)
+ target = os.path.join(os.path.dirname(link_name), source)
+ if os.path.isdir(target):
+ platform_utils_win32.create_dirsymlink(source, link_name)
+ else:
+ platform_utils_win32.create_filesymlink(source, link_name)
+ else:
+ return os.symlink(source, link_name)
+
+
+def _validate_winpath(path):
+ path = os.path.normpath(path)
+ if _winpath_is_valid(path):
+ return path
+ raise ValueError("Path \"%s\" must be a relative path or an absolute "
+ "path starting with a drive letter".format(path))
+
+
+def _winpath_is_valid(path):
+ """Windows only: returns True if path is relative (e.g. ".\\foo") or is
+ absolute including a drive letter (e.g. "c:\\foo"). Returns False if path
+ is ambiguous (e.g. "x:foo" or "\\foo").
+ """
+ assert isWindows()
+ path = os.path.normpath(path)
+ drive, tail = os.path.splitdrive(path)
+ if tail:
+ if not drive:
+ return tail[0] != os.sep # "\\foo" is invalid
+ else:
+ return tail[0] == os.sep # "x:foo" is invalid
+ else:
+ return not drive # "x:" is invalid