102 lines
3.7 KiB
Ruby
102 lines
3.7 KiB
Ruby
module Virtual
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# collection of the simple ones, int and strings and such
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module Compiler
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# Constant expressions can by definition be evaluated at compile time.
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# But that does not solve their storage, ie they need to be accessible at runtime from _somewhere_
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# So we view ConstantExpressions like functions that return the value of the constant.
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# In other words, their storage is the return slot as it would be for a method
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# The current approach moves the constant into a variable before using it
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# But in the future (in the one that holds great things) we optimize those unneccesay moves away
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# attr_reader :value
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def self.compile_integer expression , method
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int = expression.value
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to = Return.new(Integer , int)
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method.info.add_code Set.new( int , to )
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to
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end
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def self.compile_true expression , method
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to = Return.new(Reference , true )
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method.info.add_code Set.new( true , to )
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to
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end
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def self.compile_false expression , method
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to = Return.new(Reference , false)
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method.info.add_code Set.new( false , to )
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to
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end
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def self.compile_nil expression , method
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to = Return.new(Reference , nil)
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method.info.add_code Set.new( nil , to )
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to
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end
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# attr_reader :name
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# compiling name needs to check if it's a variable and if so resolve it
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# otherwise it's a method without args and a send is issued.
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# whichever way this goes the result is stored in the return slot (as all compiles)
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def self.compile_name expression , method
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return Self.new( Reference.new(method.for_class)) if expression.name == :self
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name = expression.name.to_sym
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if method.has_var(name)
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# either an argument, so it's stored in message
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if( index = method.has_arg(name))
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method.info.add_code MessageGet.new(expression.name , index)
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else # or a local so it is in the frame
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method.info.add_code FrameGet.new(expression.name , index)
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end
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else
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call = Ast::CallSiteExpression.new(expression.name , [] ) #receiver self is implicit
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Compiler.compile(call, method)
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end
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end
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def self.compile_module expression , method
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clazz = Space.space.get_class_by_name name
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raise "uups #{clazz}.#{name}" unless clazz
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to = Return.new(Reference , clazz )
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method.info.add_code Set.new( clazz , to )
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to
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end
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# attr_reader :string
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def self.compile_string expression , method
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# Clearly a TODO here to implement strings rather than reusing symbols
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value = expression.string.to_sym
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to = Return.new(Reference , value)
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method.info.constants << value
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method.info.add_code Set.new( value , to )
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to
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end
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#attr_reader :left, :right
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def self.compile_assignment expression , method
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unless expression.left.instance_of? Ast::NameExpression
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raise "must assign to NameExpression , not #{expression.left}"
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end
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r = Compiler.compile(expression.right , method )
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raise "oh noo, nil from where #{expression.right.inspect}" unless r
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index = method.has_arg(expression.left.name.to_sym)
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if index
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method.info.add_code Set.new(MessageSlot.new(index , r,type , r ) , Return.new)
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else
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index = method.ensure_local(expression.left.name.to_sym)
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method.info.add_code Set.new(FrameSlot.new(index , r.type , r ) , Return.new)
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end
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r
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end
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def self.compile_variable expression, method
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method.info.add_code InstanceGet.new(expression.name)
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Return.new( Unknown )
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end
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end
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end
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