1 files changed, 114 insertions, 0 deletions
diff --git a/codegen/vulkan/scripts/spec_tools/attributes.py b/codegen/vulkan/scripts/spec_tools/attributes.py
new file mode 100644
index 00000000..ef771811
--- /dev/null
+++ b/codegen/vulkan/scripts/spec_tools/attributes.py
@@ -0,0 +1,114 @@
+#!/usr/bin/python3 -i
+#
+# Copyright 2013-2021 The Khronos Group Inc.
+#
+# SPDX-License-Identifier: Apache-2.0
+"""Utilities for working with attributes of the XML registry."""
+
+import re
+
+_PARAM_REF_NAME_RE = re.compile(
+    r"(?P<name>[\w]+)(?P<brackets>\[\])?(?P<delim>\.|::|->)?")
+
+
+def _split_param_ref(val):
+    return [name for name, _, _ in _PARAM_REF_NAME_RE.findall(val)]
+
+
+def _human_readable_deref(val, make_param_name=None):
+    """Turn the "name[].member[]" notation into plain English."""
+    parts = []
+    matches = _PARAM_REF_NAME_RE.findall(val)
+    for name, brackets, delim in reversed(matches):
+        if make_param_name:
+            name = make_param_name(name)
+        if delim:
+            parts.append('member of')
+        if brackets:
+            parts.append('each element of')
+        parts.append('the')
+        parts.append(name)
+    parts.append('parameter')
+    return ' '.join(parts)
+
+
+class LengthEntry:
+    """An entry in a (comma-separated) len attribute"""
+    NULL_TERMINATED_STRING = 'null-terminated'
+    MATH_STRING = 'latexmath:'
+
+    def __init__(self, val):
+        self.full_reference = val
+        self.other_param_name = None
+        self.null_terminated = False
+        self.number = None
+        self.math = None
+        self.param_ref_parts = None
+        if val == LengthEntry.NULL_TERMINATED_STRING:
+            self.null_terminated = True
+            return
+
+        if val.startswith(LengthEntry.MATH_STRING):
+            self.math = val.replace(LengthEntry.MATH_STRING, '')[1:-1]
+            return
+
+        if val.isdigit():
+            self.number = int(val)
+            return
+
+        # Must be another param name.
+        self.param_ref_parts = _split_param_ref(val)
+        self.other_param_name = self.param_ref_parts[0]
+
+    def __str__(self):
+        return self.full_reference
+
+    def get_human_readable(self, make_param_name=None):
+        assert(self.other_param_name)
+        return _human_readable_deref(self.full_reference, make_param_name=make_param_name)
+
+    def __repr__(self):
+        "Formats an object for repr(), debugger display, etc."
+        return 'spec_tools.attributes.LengthEntry("{}")'.format(self.full_reference)
+
+    @staticmethod
+    def parse_len_from_param(param):
+        """Get a list of LengthEntry."""
+        len_str = param.get('len')
+        if len_str is None:
+            return None
+        return [LengthEntry(elt) for elt in len_str.split(',')]
+
+
+class ExternSyncEntry:
+    """An entry in a (comma-separated) externsync attribute"""
+
+    TRUE_STRING = 'true'
+    TRUE_WITH_CHILDREN_STRING = 'true_with_children'
+
+    def __init__(self, val):
+        self.full_reference = val
+        self.entirely_extern_sync = (val in (ExternSyncEntry.TRUE_STRING, ExternSyncEntry.TRUE_WITH_CHILDREN_STRING))
+        self.children_extern_sync = (val == ExternSyncEntry.TRUE_WITH_CHILDREN_STRING)
+        if self.entirely_extern_sync:
+            return
+
+        self.param_ref_parts = _split_param_ref(val)
+        self.member = self.param_ref_parts[0]
+
+    def get_human_readable(self, make_param_name=None):
+        assert(not self.entirely_extern_sync)
+        return _human_readable_deref(self.full_reference, make_param_name=make_param_name)
+
+    @staticmethod
+    def parse_externsync_from_param(param):
+        """Get a list of ExternSyncEntry."""
+        sync_str = param.get('externsync')
+        if sync_str is None:
+            return None
+        return [ExternSyncEntry(elt) for elt in sync_str.split(',')]
+
+    def __repr__(self):
+        "Formats an object for repr(), debugger display, etc."
+        return 'spec_tools.attributes.ExternSyncEntry("{}")'.format(self.full_reference)
+