rubyx/lib/mom/instruction/block_yield.rb

40 lines
1.1 KiB
Ruby

module Mom
# A BlockYield calls an argument block. All we need to know is the index
# of the argument, and the rest is almost as simple as a SimpleCall
class BlockYield < Instruction
attr :arg_index
# pass in the source (vool statement) and the index.
# The index is the argument index of the block that we call
def initialize(source , index)
super(source)
@arg_index = index
end
def to_s
"BlockYield[#{arg_index}] "
end
# almost as simple as a SimpleCall, use a dynamic_jump to get there
def to_risc(compiler)
return_label = Risc.label("block_yield", "continue_#{object_id}")
index = arg_index
compiler.build("BlockYield") do
next_message! << message[:next_message]
return_address! << return_label
next_message[:return_address] << return_address
block_reg! << message[:arguments]
block_reg << block_reg[index]
message << message[:next_message]
add_code Risc::DynamicJump.new("block_yield", block_reg )
add_code return_label
end
end
end
end