1 files changed, 52 insertions, 0 deletions
diff --git a/src/buildstream/_loader/_loader.pyx b/src/buildstream/_loader/_loader.pyx
new file mode 100644
index 000000000..258a34ab7
--- /dev/null
+++ b/src/buildstream/_loader/_loader.pyx
@@ -0,0 +1,52 @@
+#
+#  Copyright (C) 2019 Bloomberg L.P.
+#
+#  This program is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU Lesser General Public
+#  License as published by the Free Software Foundation; either
+#  version 2 of the License, or (at your option) any later version.
+#
+#  This library is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
+#  Lesser General Public License for more details.
+#
+#  You should have received a copy of the GNU Lesser General Public
+#  License along with this library. If not, see <http://www.gnu.org/licenses/>.
+#
+#  Authors:
+#        Benjamin Schubert <bschubert@bloomberg.net>
+#
+
+
+# Check if given filename containers valid characters.
+#
+# Args:
+#    name (str): Name of the file
+#
+# Returns:
+#    (bool): True if all characters are valid, False otherwise.
+#
+def valid_chars_name(str name):
+    cdef int char_value
+    cdef int forbidden_char
+
+    for char_value in name:
+        # 0-31 are control chars, 127 is DEL, and >127 means non-ASCII
+        if char_value <= 31 or char_value >= 127:
+            return False
+
+        # Disallow characters that are invalid on Windows. The list can be
+        # found at https://docs.microsoft.com/en-us/windows/desktop/FileIO/naming-a-file
+        #
+        # Note that although : (colon) is not allowed, we do not raise
+        # warnings because of that, since we use it as a separator for
+        # junctioned elements.
+        #
+        # We also do not raise warnings on slashes since they are used as
+        # path separators.
+        for forbidden_char in '<>"|?*':
+            if char_value == forbidden_char:
+                return False
+
+    return True