1 files changed, 119 insertions, 0 deletions
diff --git a/codegen/vulkan/scripts/spec_tools/file_process.py b/codegen/vulkan/scripts/spec_tools/file_process.py
new file mode 100644
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+++ b/codegen/vulkan/scripts/spec_tools/file_process.py
@@ -0,0 +1,119 @@
+#!/usr/bin/python3
+#
+# Copyright (c) 2018-2019 Collabora, Ltd.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+# Author(s):    Ryan Pavlik <ryan.pavlik@collabora.com>
+"Utilities for processing files."
+
+from pathlib import Path
+
+
+class LinewiseFileProcessor:
+    """A base class for code that processes an input file (or file handle) one line at a time."""
+
+    def __init__(self):
+        self._lines = []
+        self._line_num = 0
+        self._next_line = None
+        self._line = ''
+        self._filename = Path()
+
+    @property
+    def filename(self):
+        """The Path object of the currently processed file"""
+        return self._filename
+
+    @property
+    def relative_filename(self):
+        """The current file's Path relative to the current working directory"""
+        return self.filename.relative_to(Path('.').resolve())
+
+    @property
+    def line(self):
+        """The current line, including any trailing whitespace and the line ending."""
+        return self._line
+
+    @property
+    def line_number(self):
+        """Get 1-indexed line number."""
+        return self._line_num
+
+    @property
+    def line_rstripped(self):
+        """The current line without any trailing whitespace."""
+        if self.line is None:
+            return None
+        return self.line.rstrip()
+
+    @property
+    def trailing_whitespace(self):
+        """The trailing whitespace of the current line that gets removed when accessing rstrippedLine"""
+        non_whitespace_length = len(self.line_rstripped)
+        return self.line[non_whitespace_length:]
+
+    @property
+    def next_line(self):
+        """Peek at the next line, if any."""
+        return self._next_line
+
+    @property
+    def next_line_rstripped(self):
+        """Peek at the next line, if any, without any trailing whitespace."""
+        if self.next_line is None:
+            return None
+        return self.next_line.rstrip()
+
+    def get_preceding_line(self, relative_index=-1):
+        """Retrieve the line at an line number at the given relative index, if one exists. Returns None if there is no line there."""
+        if relative_index >= 0:
+            raise RuntimeError(
+                'relativeIndex must be negative, to retrieve a preceding line.')
+        if relative_index + self.line_number <= 0:
+            # There is no line at this index
+            return None
+        return self._lines[self.line_number + relative_index - 1]
+
+    def get_preceding_lines(self, num):
+        """Get *up to* the preceding num lines. Fewer may be returned if the requested number aren't available."""
+        return self._lines[- (num + 1):-1]
+
+    def process_line(self, line_num, line):
+        """Implement in your subclass to handle each new line."""
+        raise NotImplementedError
+
+    def _process_file_handle(self, file_handle):
+        # These are so we can process one line earlier than we're actually iterating thru.
+        processing_line_num = None
+        processing_line = None
+
+        def do_process_line():
+            self._line_num = processing_line_num
+            self._line = processing_line
+            if processing_line is not None:
+                self._lines.append(processing_line)
+                self.process_line(processing_line_num, processing_line)
+
+        for line_num, line in enumerate(file_handle, 1):
+            self._next_line = line
+            do_process_line()
+            processing_line_num = line_num
+            processing_line = line
+
+        # Finally process the left-over line
+        self._next_line = None
+        do_process_line()
+
+    def process_file(self, filename, file_handle=None):
+        """Main entry point - call with a filename and optionally the file handle to read from."""
+        if isinstance(filename, str):
+            filename = Path(filename).resolve()
+
+        self._filename = filename
+
+        if file_handle:
+            self._process_file_handle(file_handle)
+        else:
+            with self._filename.open('r', encoding='utf-8') as f:
+                self._process_file_handle(f)