1 files changed, 59 insertions, 0 deletions
diff --git a/Tools/bgen/bgen/bgenStackBuffer.py b/Tools/bgen/bgen/bgenStackBuffer.py
new file mode 100644
index 0000000000..b7df5bdf62
--- /dev/null
+++ b/Tools/bgen/bgen/bgenStackBuffer.py
@@ -0,0 +1,59 @@
+"""Buffers allocated on the stack."""
+
+
+from bgenBuffer import FixedInputBufferType, FixedOutputBufferType
+
+
+class StackOutputBufferType(FixedOutputBufferType):
+
+	"""Fixed output buffer allocated on the stack -- passed as (buffer, size).
+
+	Instantiate with the buffer size as parameter.
+	"""
+
+	def passOutput(self, name):
+		return "%s__out__, %s" % (name, self.size)
+
+
+class VarStackOutputBufferType(StackOutputBufferType):
+
+	"""Output buffer allocated on the stack -- passed as (buffer, &size).
+
+	Instantiate with the buffer size as parameter.
+	"""
+
+	def declareSize(self, name):
+		Output("int %s__len__ = %s;", name, self.size)
+
+	def passOutput(self, name):
+		return "%s__out__, &%s__len__" % (name, name)
+
+	def mkvalueArgs(self, name):
+		return "%s__out__, %s__len__" % (name, name)
+
+
+class VarVarStackOutputBufferType(VarStackOutputBufferType):
+
+	"""Output buffer allocated on the stack -- passed as (buffer, size, &size).
+
+	Instantiate with the buffer size as parameter.
+	"""
+
+	def passOutput(self, name):
+		return "%s__out__, %s__len__, &%s__len__" % (name, name, name)
+
+
+class ReturnVarStackOutputBufferType(VarStackOutputBufferType):
+
+	"""Output buffer allocated on the stack -- passed as (buffer, size) -> size.
+
+	Instantiate with the buffer size as parameter.
+	The function's return value is the size.
+	(XXX Should have a way to suppress returning it separately, too.)
+	"""
+
+	def passOutput(self, name):
+		return "%s__out__, %s__len__" % (name, name)
+
+	def mkvalueArgs(self, name):
+		return "%s__out__, _rv" % name