1 files changed, 83 insertions, 0 deletions
diff --git a/scripts/ninja_rsp.py b/scripts/ninja_rsp.py
new file mode 100644
index 000000000..004ce4733
--- /dev/null
+++ b/scripts/ninja_rsp.py
@@ -0,0 +1,83 @@
+# Copyright (C) 2020 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+"""This file reads entries from a Ninja rsp file."""
+
+class NinjaRspFileReader:
+  """
+  Reads entries from a Ninja rsp file.  Ninja escapes any entries in the file that contain a
+  non-standard character by surrounding the whole entry with single quotes, and then replacing
+  any single quotes in the entry with the escape sequence '\''.
+  """
+
+  def __init__(self, filename):
+    self.f = open(filename, 'r')
+    self.r = self.character_reader(self.f)
+
+  def __iter__(self):
+    return self
+
+  def character_reader(self, f):
+    """Turns a file into a generator that returns one character at a time."""
+    while True:
+      c = f.read(1)
+      if c:
+        yield c
+      else:
+        return
+
+  def __next__(self):
+    entry = self.read_entry()
+    if entry:
+      return entry
+    else:
+      raise StopIteration
+
+  def read_entry(self):
+    c = next(self.r, "")
+    if not c:
+      return ""
+    elif c == "'":
+      return self.read_quoted_entry()
+    else:
+      entry = c
+      for c in self.r:
+        if c == " " or c == "\n":
+          break
+        entry += c
+      return entry
+
+  def read_quoted_entry(self):
+    entry = ""
+    for c in self.r:
+      if c == "'":
+        # Either the end of the quoted entry, or the beginning of an escape sequence, read the next
+        # character to find out.
+        c = next(self.r)
+        if not c or c == " " or c == "\n":
+          # End of the item
+          return entry
+        elif c == "\\":
+          # Escape sequence, expect a '
+          c = next(self.r)
+          if c != "'":
+            # Malformed escape sequence
+            raise "malformed escape sequence %s'\\%s" % (entry, c)
+          entry += "'"
+        else:
+          raise "malformed escape sequence %s'%s" % (entry, c)
+      else:
+        entry += c
+    raise "unterminated quoted entry %s" % entry