racket/collects/gui-debugger/annotator.ss
2009-03-26 19:18:22 +00:00

398 lines
19 KiB
Scheme

(module annotator scheme/base
(require (prefix-in kernel: syntax/kerncase)
gui-debugger/marks
mzlib/etc
(prefix-in srfi: srfi/1/search)
(for-syntax scheme/base)
(only-in mzscheme [apply plain-apply])
)
(provide annotate-stx annotate-for-single-stepping)
(define (arglist-bindings arglist-stx)
(syntax-case arglist-stx ()
[var
(identifier? arglist-stx)
(list arglist-stx)]
[(var ...)
(syntax->list arglist-stx)]
[(var . others)
(cons #'var (arglist-bindings #'others))]))
;; Retreives the binding of a variable from a normal-breakpoint-info.
;; Returns a list of pairs `(,variable-name-stx ,variable-value). Each
;; item in the list is a shadowed instance of a variable with the given
;; name, with the first item being the one in scope.
#;
(define (bindings top-mark marks sym)
(let ([mark-list (cons top-mark (continuation-mark-set->list marks debug-key))])
(map (lambda (binding) (list (mark-binding-binding binding)
(mark-binding-value binding)))
(lookup-all-bindings (lambda (id) (eq? (syntax-e id) sym))
mark-list))))
;; annotate-for-single-stepping uses annotate-stx to create an annotated
;; version of STX that pauses before and after each expression, in the style
;; of a single stepping debugger.
;;
;; BREAK?, BREAK-BEFORE, BREAK-AFTER are inserted into the resulting syntax
;; as 3D code. When the resulting syntax is evaluated, before each
;; expression is evaluated, BREAK? is called with the syntax position of
;; that expression. If BREAK? returns true, BREAK-BEFORE is called with two
;; arguments: the debug-info structure representing the first stack frame
;; and the current continuation marks representing the other stack frames
;; (use the key DEBUG-KEY). If BREAK-BEFORE returns some value, the
;; evaluation skips the expression entirely and just returns that value.
;; Otherwise, evaluation proceeds normally. After the expression is
;; evaluated, BREAK? is called with the position of the end of the expression.
;; If it returns true, BREAK-AFTER is called; otherwise, the expression returns
;; normally. If BREAK-AFTER returns some value, the
;; return value of the expression is replaced by that value.
;;
;; RECORD-BOUND-ID and RECORD-TOP-LEVEL-ID are simply passed to ANNOTATE-STX.
(define annotate-for-single-stepping
(opt-lambda (stx break? break-before break-after record-bound-id record-top-level-id [source #f])
(annotate-stx
stx
(lambda (debug-info annotated raw is-tail?)
(let* ([start (syntax-position raw)]
[end (+ start (syntax-span raw) -1)]
[break? (break? (syntax-source raw))])
(if is-tail?
#`(let-values ([(value-list) #f])
(if (#%plain-app #,break? #,start)
(set! value-list (#%plain-app
#,break-before
#,debug-info
(#%plain-app current-continuation-marks)))
(#%plain-app void))
(if (#%plain-app not value-list)
#,annotated
(#%plain-app plain-apply values value-list)))
#`(let-values ([(value-list) #f])
(if (#%plain-app #,break? #,start)
(set! value-list (#%plain-app
#,break-before
#,debug-info
(#%plain-app current-continuation-marks)))
(#%plain-app void))
(if (#%plain-app not value-list)
(#%plain-app
call-with-values
(#%plain-lambda () #,annotated)
(case-lambda
[(val) (if (#%plain-app #,break? #,end)
(#%plain-app
#,break-after
#,debug-info
(#%plain-app current-continuation-marks) val)
val)]
[vals (if (#%plain-app
#,break? #,end)
(#%plain-app
plain-apply
#,break-after
#,debug-info
(#%plain-app current-continuation-marks) vals)
(#%plain-app plain-apply values vals))]))
(if (#%plain-app #,break? #,end)
(#%plain-app
plain-apply #,break-after
#,debug-info
(#%plain-app current-continuation-marks)
value-list)
(#%plain-app plain-apply values value-list)))))))
record-bound-id
record-top-level-id
source)))
; annotate-stx : (syntax?
; (mark? syntax? syntax? boolean? . -> . syntax?)
; (symbol? syntax? syntax? . -> . void?)
; . -> .
; syntax?)
;; annotate-stx consumes a syntax, transverses it, and gives the opportunity
;; to the break-wrap to annotate every expression. Once for each expression
;; in the source program, annotate-stx will call break-wrap with that
;; expression as an argument and insert the result in the original syntax.
;; Expressions that were duplicated during the macro expansion are
;; nevertheless only wrapped once.
;;
;; annotate-stx inserts annotations around each expression that introduces a
;; new scope: let, lambda, and function calls. These annotations reify the
;; call stack, and allows to list the current variable in scope, look up
;; their value, as well as change their value. The reified stack is accessed
;; via the CURRENT-CONTINUATION-MARKS using the key DEBUG-KEY
;;
;; BREAK-WRAP is called with four arguments:
;; debug-info : the top frame of the reified stack (which never changes
;; across execution)
;; annotate-stx : the syntax with its subbranches already
;; annotated. BREAK-WRAP should return a modified version of this syntax.
;; original-stx : the original syntax before annoatations
;; is-tail? : true when original syntax was in tail position
;;
;; The RECORD-BOUND-ID function is a callback that is invoked each time a
;; new variable is introduced, looked up, or set in STX (lexically).
;; RECORD-BOUND-ID takes three arguments:
;; use-case : either 'bind or 'ref or 'set, respectively
;; bound-stx : syntax where the symbol is introduced, looked up, set, respectively
;; binding-stx : syntax where the symbol was bound
;;
;; Naturally, when USE-CASE is 'bind, BOUND-STX and BINDING-STX are equal.
;;
(define annotate-stx
(opt-lambda (stx break-wrap record-bound-id record-top-level-id [source #f])
(define breakpoints (make-hasheq))
(define (previous-bindings bound-vars)
(if (null? bound-vars)
#'null
#'(#%plain-app debugger-local-bindings)))
(define (top-level-annotate stx)
(kernel:kernel-syntax-case/phase
stx (namespace-base-phase)
[(module identifier name (plain-module-begin . module-level-exprs))
(with-syntax ([(module . _) stx])
(quasisyntax/loc stx (module identifier name
(plain-module-begin
#,@(map (lambda (e) (module-level-expr-iterator
e (list (syntax-e #'identifier)
(syntax-source #'identifier))))
(syntax->list #'module-level-exprs))))))]
[else-stx
(general-top-level-expr-iterator stx #f)]))
(define (module-level-expr-iterator stx module-name )
(kernel:kernel-syntax-case
stx #f
[(#%provide . provide-specs)
stx]
[else-stx
(general-top-level-expr-iterator stx module-name )]))
(define (general-top-level-expr-iterator stx module-name )
(kernel:kernel-syntax-case
stx #f
[(define-values (var ...) expr)
(begin
(for-each (lambda (v) (record-bound-id 'bind v v))
(syntax->list #'(var ...)))
(quasisyntax/loc stx
(begin (define-values (var ...) #,(annotate #`expr '() #t module-name))
#,(if (syntax-source stx)
#`(begin (#%plain-app
#,record-top-level-id '#,module-name #'var (case-lambda
[() var]
[(v) (set! var v)])) ...)
#'(#%plain-app void))
(#%plain-app void)))
)
]
[(define-syntaxes (var ...) expr)
stx]
[(define-values-for-syntax (var ...) expr)
;; define-values-for-syntax's RHS is compile time, so treat it
;; like define-syntaxes
stx]
[(begin . top-level-exprs)
(quasisyntax/loc stx (begin #,@(map (lambda (expr)
(module-level-expr-iterator expr module-name ))
(syntax->list #'top-level-exprs))))]
[(#%require . require-specs)
stx]
[else
(annotate stx '() #f module-name )]))
(define (annotate expr bound-vars is-tail? module-name)
(define annotate-break?
(let ([pos (syntax-position expr)]
[src (syntax-source expr)])
(and src pos
(hash-ref breakpoints pos (lambda () #t))
(kernel:kernel-syntax-case
expr #f
[(if test then else) #t]
[(begin . bodies) #t]
[(begin0 . bodies) #t]
[(let-values . clause) #t]
[(letrec-values . clause) #t]
[(set! var val) #t]
[(with-continuation-mark key mark body) #t]
[(#%plain-app . exprs) #t]
[_ #f])
(begin
(hash-set! breakpoints pos #f)
(when (not is-tail?)
(hash-set! breakpoints (+ pos (syntax-span expr) -1) #f))
#t))))
(define (let/rec-values-annotator letrec?)
(kernel:kernel-syntax-case
expr #f
[(label (((var ...) rhs) ...) . bodies)
(let* ([new-bindings (apply append
(map syntax->list
(syntax->list #`((var ...) ...))))]
[all-bindings (append new-bindings bound-vars)]
[new-rhs (map (lambda (expr)
(annotate expr
(if letrec? all-bindings bound-vars)
#f module-name ))
(syntax->list #'(rhs ...)))]
[last-body (car (reverse (syntax->list #'bodies)))]
[all-but-last-body (reverse (cdr (reverse (syntax->list #'bodies))))]
[bodies (append (map (lambda (expr)
(annotate expr all-bindings #f module-name ))
all-but-last-body)
(list (annotate
last-body
all-bindings
is-tail? module-name )))]
[local-debug-info (assemble-debug-info new-bindings new-bindings 'normal #f)]
[previous-bindings (previous-bindings bound-vars)])
(for-each (lambda (id) (record-bound-id 'bind id id)) new-bindings)
(with-syntax ([(new-rhs/trans ...) new-rhs]
[previous-bindings previous-bindings])
(if letrec?
(quasisyntax/loc expr
(let ([old-bindings previous-bindings])
(label (((debugger-local-bindings) (#%plain-lambda ()
(#%plain-app
list*
#,@local-debug-info
old-bindings)))
((var ...) new-rhs/trans) ...)
#,@bodies)))
(quasisyntax/loc expr
(label (((var ...) new-rhs/trans) ...)
(let ([debugger-local-bindings (#%plain-lambda ()
(#%plain-app
list*
#,@local-debug-info
previous-bindings))])
#,@bodies))))))]))
(define (lambda-clause-annotator clause)
(kernel:kernel-syntax-case
clause #f
[(arg-list . bodies)
(let* ([new-bound-vars (arglist-bindings #'arg-list)]
[all-bound-vars (append new-bound-vars bound-vars)]
[new-bodies (let loop ([bodies (syntax->list #'bodies)])
(if (equal? '() (cdr bodies))
(list (annotate (car bodies) all-bound-vars #t module-name ))
(cons (annotate (car bodies) all-bound-vars #f module-name )
(loop (cdr bodies)))))])
(for-each (lambda (id) (record-bound-id 'bind id id)) new-bound-vars)
(quasisyntax/loc clause
(arg-list
(let ([debugger-local-bindings
(#%plain-lambda ()
(#%plain-app
list*
#,@(assemble-debug-info new-bound-vars new-bound-vars 'normal #f)
#,(previous-bindings bound-vars)))])
#,@new-bodies))))]))
(define annotated
(syntax-recertify
(kernel:kernel-syntax-case
expr #f
[var-stx (identifier? (syntax var-stx))
(let ([binder (and (syntax-original? expr)
(srfi:member expr bound-vars free-identifier=?))])
(if binder
(record-bound-id 'ref expr (car binder))
(record-bound-id 'top-level expr expr))
expr)]
[(#%plain-lambda . clause)
(quasisyntax/loc expr
(#%plain-lambda #,@(lambda-clause-annotator #'clause)))]
[(case-lambda . clauses)
(quasisyntax/loc expr
(case-lambda #,@(map lambda-clause-annotator (syntax->list #'clauses))))]
[(if test then else)
(quasisyntax/loc expr (if #,(annotate #'test bound-vars #f module-name )
#,(annotate #'then bound-vars is-tail? module-name )
#,(annotate #'else bound-vars is-tail? module-name )))]
[(begin . bodies)
(letrec ([traverse
(lambda (lst)
(if (and (pair? lst) (equal? '() (cdr lst)))
`(,(annotate (car lst) bound-vars is-tail? module-name ))
(cons (annotate (car lst) bound-vars #f module-name )
(traverse (cdr lst)))))])
(quasisyntax/loc expr (begin #,@(traverse (syntax->list #'bodies)))))]
[(begin0 . bodies)
(quasisyntax/loc expr (begin0 #,@(map (lambda (expr)
(annotate expr bound-vars #f module-name ))
(syntax->list #'bodies))))]
[(let-values . clause)
(let/rec-values-annotator #f)]
[(letrec-values . clause)
(let/rec-values-annotator #t)]
[(set! var val)
(let ([binder (and (syntax-original? #'var)
(srfi:member #'var bound-vars free-identifier=?))])
(when binder
(record-bound-id 'set expr (car binder)))
(quasisyntax/loc expr (set! var #,(annotate #`val bound-vars #f module-name ))))]
[(quote _) expr]
[(quote-syntax _) expr]
[(with-continuation-mark key mark body)
(quasisyntax/loc expr (with-continuation-mark key
#,(annotate #'mark bound-vars #f module-name )
#,(annotate #'body bound-vars is-tail? module-name )))]
[(#%plain-app . exprs)
(let ([subexprs (map (lambda (expr)
(annotate expr bound-vars #f module-name ))
(syntax->list #'exprs))])
(if (or is-tail? (not (syntax-source expr)))
(quasisyntax/loc expr (#%plain-app . #,subexprs))
(wcm-wrap (make-debug-info module-name expr bound-vars bound-vars 'normal #f (previous-bindings bound-vars))
(quasisyntax/loc expr (#%plain-app . #,subexprs)))))]
[(#%top . var) expr]
[(#%variable-reference . _) expr]
[else (error 'expr-syntax-object-iterator "unknown expr: ~a"
(syntax->datum expr))])
expr
(current-code-inspector)
#f))
(if annotate-break?
(break-wrap
(make-debug-info module-name expr bound-vars bound-vars 'at-break #f (previous-bindings bound-vars))
annotated
expr
is-tail?)
annotated))
(values (top-level-annotate stx) (hash-map breakpoints (lambda (k v) k))))))