Here is a list of all variables with links to the structures/unions they belong to:

_abi_padding : RsvgHandle, RsvgHandleClass
em : RsvgDimensionData
ex : RsvgDimensionData
height : RsvgDimensionData, RsvgRectangle
length : RsvgLength
parent : RsvgHandle, RsvgHandleClass
unit : RsvgLength
width : RsvgDimensionData, RsvgRectangle
x : RsvgPositionData, RsvgRectangle
y : RsvgPositionData, RsvgRectangle