factor/basis/stack-checker/state/state.factor

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1.9 KiB
Factor

! Copyright (C) 2008 Slava Pestov.
! See http://factorcode.org/license.txt for BSD license.
USING: assocs arrays namespaces sequences kernel definitions
math effects accessors words fry classes.algebra
compiler.units stack-checker.values stack-checker.visitor ;
IN: stack-checker.state
! Did the current control-flow path throw an error?
SYMBOL: terminated?
! Number of inputs current word expects from the stack
SYMBOL: d-in
DEFER: commit-literals
! Compile-time data stack
: meta-d ( -- stack ) commit-literals \ meta-d get ;
! Compile-time retain stack
: meta-r ( -- stack ) \ meta-r get ;
! Uncommitted literals. This is a form of local dead-code
! elimination; the goal is to reduce the number of IR nodes
! which get constructed. Technically it is redundant since
! we do global DCE later, but it speeds up compile time.
SYMBOL: literals
: (push-literal) ( obj -- )
dup <literal> make-known
[ nip \ meta-d get push ] [ #push, ] 2bi ;
: commit-literals ( -- )
literals get [
[ [ (push-literal) ] each ] [ delete-all ] bi
] unless-empty ;
: current-stack-height ( -- n ) meta-d length d-in get - ;
: current-effect ( -- effect )
d-in get
meta-d length <effect>
terminated? get >>terminated? ;
: init-inference ( -- )
terminated? off
V{ } clone \ meta-d set
V{ } clone literals set
0 d-in set ;
! Words that the current quotation depends on
SYMBOL: dependencies
: depends-on ( word how -- )
over primitive? [ 2drop ] [
dependencies get dup [
swap '[ _ strongest-dependency ] change-at
] [ 3drop ] if
] if ;
! Generic words that the current quotation depends on
SYMBOL: generic-dependencies
: ?class-or ( class/f class -- class' )
swap [ class-or ] when* ;
: depends-on-generic ( generic class -- )
generic-dependencies get dup
[ swap '[ _ ?class-or ] change-at ] [ 3drop ] if ;
! Words we've inferred the stack effect of, for rollback
SYMBOL: recorded