racket/collects/mztake/engine.ss

354 lines
15 KiB
Scheme

(module engine mzscheme
(require "marks.ss"
(prefix frp: (lib "lang-ext.ss" "frtime"))
(rename (lib "frp-core.ss" "frtime")
frp:signal-thunk signal-thunk)
"useful-code.ss"
"more-useful-code.ss" ; mostly for hash- bindings
"mztake-structs.ss"
"load-sandbox.ss"
"annotator.ss")
(provide process:set-main!
current-policy
all-debug-processes
create-debug-process
process:->dead
process:new->running
process:running->finished
process:running->paused
process:paused->running
pause
resume
trace*)
;Keeps track of all debugging processes
(define all-debug-processes null)
;; returns a memoized function that takes (line column) -> position
;; line-col->pos : (debug-file? . -> . (number? number? . -> . (union void? number?)))
(define (line-col->pos filename)
; produces a nested list of (line column offset) for all addressable syntax
(define (unwrap-syntax stx)
(let ([elt (list (syntax-line stx)
(syntax-column stx)
(sub1 (syntax-position stx)))])
(syntax-case stx ()
[(item ...) (cons elt (map unwrap-syntax (syntax->list stx)))]
[x elt])))
(let ([pos-list
(flatten (parameterize ([port-count-lines-enabled #t])
(let ([port (open-input-file filename)])
(begin0
(let loop ([stx (read-syntax filename port)])
(if (eof-object? stx) '()
(cons (unwrap-syntax stx)
(loop (read-syntax filename port)))))
(close-input-port port)))))])
(lambda (line maybe-col)
(let loop ([lst pos-list])
(cond
[(empty? lst)
(error 'loc
"No syntax found for trace at line/column ~a:~a in client `~a'"
line maybe-col filename)]
[(and (<= line (first (first lst)))
(or (not maybe-col)
(<= maybe-col (second (first lst)))))
(third (first lst))]
[else (loop (rest lst))])))))
(define (find-client process modpath)
(cond
[(memf (lambda (c) (equal? (debug-client-modpath c) modpath))
(debug-process-clients process)) => first]
[else false]))
(define (find-client/create process modpath)
(or (find-client process modpath)
(create-debug-client process modpath)))
(define (process:set-main! p reqspec)
(let* ([modpath (reqspec->modpath reqspec)]
[client (find-client/create p modpath)])
(set-debug-process-main-client! p client)))
(define (break? process client)
(let ([tracepoints (and client (debug-client-tracepoints client))])
(lambda (pos)
(or (debug-process-pause-requested? process)
(and tracepoints
(hash-get tracepoints (sub1 pos) (lambda () false)))))))
(define (traces->events traces)
(map (lambda (t)
(list (trace-struct-evnt-rcvr t)
((trace-struct-thunk t))))
traces))
(define (receive-result process client top-mark rest-marks)
(let* ([byte-offset (sub1 (syntax-position (mark-source top-mark)))]
[traces (hash-get (debug-client-tracepoints client) byte-offset (lambda () empty))]
[no-traces? (empty? traces)]
[has-single-trace? (and (not no-traces?) (empty? (rest traces)))]
[no-where? (not (debug-process-where process))]
[no-events? (and no-traces? no-where?
(not (debug-process-pause-requested? process)))])
(unless no-events?
(let* ([marks (cons top-mark (continuation-mark-set->list rest-marks debug-key))])
(set-debug-process-marks! process marks)
(if no-where?
;; No where event to generate
(cond [has-single-trace?
;; fast-path
(let ([t (first traces)])
(frp:send-synchronous-event (trace-struct-evnt-rcvr t)
((trace-struct-thunk t))))]
[no-traces? void]
[else (frp:send-synchronous-events (traces->events traces))])
;; With a where event to generate
(let ([where-event ((frp:signal-thunk (debug-process-where process)) #t)]
[w (map (compose syntax-local-infer-name mark-source) marks)])
(if no-traces?
(frp:send-synchronous-event where-event w)
(let* ([where-event (list where-event w)]
[trace-events (traces->events traces)])
(frp:send-synchronous-events (cons where-event trace-events))))))
;; Now that we processed the trace, do we want to pause or continue
(when (debug-process-pause-requested? process)
(let loop ()
(unless (debug-process-resume-requested? process)
(semaphore-wait (debug-process-run-semaphore process))
(loop)))
(set-debug-process-pause-requested?! process false)
(set-debug-process-resume-requested?! process false))
(set-debug-process-marks! process false)))))
(define ((break-after process client) top-mark marks . vals)
(receive-result process client top-mark marks) ; TODO: have access to return value
(apply values vals)) ; TODO: allow modification of the return value
(define ((break-before process client) top-mark marks)
(receive-result process client top-mark marks) ; TODO: allow substitute value
false)
(define (unbuild-path path)
(let-values ([(base name _) (split-path path)])
(if base
(append (unbuild-path base) (list name))
empty)))
(define (head lst n)
(if (= n 0)
empty
(cons (first lst) (head (rest lst) (sub1 n)))))
(define (dir-contains? dir filename)
(let ([dir-lst (unbuild-path dir)])
(equal? dir-lst (head (unbuild-path filename) (length dir-lst)))))
(define (map-policy-tag tag)
(cond [(eq? tag 'fast) false]
[(eq? tag 'debuggable) true]
[else (error 'map-policy-tag "unknown policy tag ~a" tag)]))
(define (policy-requests-annotatation? policy filename)
(if (empty? policy)
true
(let ([tag (first (first policy))]
[collect-paths (second (first policy))])
(map-policy-tag tag) ;; complains if the tag doesn't exists
(if (or (eq? collect-paths 'everything-else)
(ormap (lambda (dir) (dir-contains? dir filename))
(if (list? collect-paths)
collect-paths
(list collect-paths))))
(map-policy-tag tag)
(policy-requests-annotatation? (rest policy) filename)))))
(define (process-has-file? process filename)
(and
(memf (lambda (c) (equal? (debug-client-modpath c)
(path->string filename)));; TODO: harmonize path & string
(debug-process-clients process))
true))
(define (launch-sandbox process)
(unless (debug-process-main-client process)
(error 'launch-sandbox
"No main file specified. Use TRACE or SET-MAIN! to indicate where to start execution"))
(parameterize ([current-inspector (make-inspector)])
(require/sandbox+annotations
(debug-process-custodian process)
;; error-display-handler :
(let ([orig-err-disp (error-display-handler)])
(lambda (msg exn)
(frp:send-event (debug-process-exceptions process) exn)
(orig-err-disp msg exn)))
;; target file
`(file ,(debug-client-modpath (debug-process-main-client process)))
;; annotate-module?
(lambda (filename module-name)
(or (process-has-file? process filename)
(policy-requests-annotatation? (debug-process-policy process) filename)))
;; annotator
(lambda (stx)
(if (not (syntax-source stx))
stx
(let*-values ([(client) (find-client/create process (path->string (syntax-source stx)))]
[(annotated-stx pos-list)
(annotate-for-single-stepping
stx
(break? process client)
(break-before process client)
(break-after process client)
(lambda (kind bound binding) (void)))])
annotated-stx))))))
(define (process:new->running process)
(set-debug-process-run-semaphore! process (make-semaphore))
(set-debug-process-policy! process (current-policy))
(thread (lambda ()
(launch-sandbox process)
(process:running->finished process))))
(define (process:running->finished process)
(process:->dead process))
(define (process:->dead process)
(set! all-debug-processes (remq process all-debug-processes))
(custodian-shutdown-all (debug-process-custodian process))
(frp:set-cell! (debug-process-exited? process) true))
(define (process:running->paused process)
(set-debug-process-pause-requested?! process true))
(define (process:paused->running process)
(set-debug-process-resume-requested?! process true)
(semaphore-post (debug-process-run-semaphore process)))
(define (pause process)
(when (and (debug-process-run-semaphore process)
(not (frp:value-now (debug-process-exited? process)))
(not (debug-process-pause-requested? process)))
(process:running->paused process)))
(define (resume process)
(cond
[(not (debug-process-run-semaphore process)) (process:new->running process)]
[(and (not (frp:value-now (debug-process-exited? process)))
(debug-process-pause-requested? process)
(not (debug-process-resume-requested? process)))
(process:paused->running process)]))
(define current-policy (make-parameter `((fast ,(current-library-collection-paths))
(debuggable everything-else))))
(define (create-debug-process)
(letrec ([running-e (frp:new-cell frp:never-e)]
[run-manager (running-e . frp:==> .
(lambda (r)
(if r (resume process) (pause process))))]
[process (make-debug-process (make-custodian)
false ; run-semaphore - false so we know it has never started
running-e ; running-e
run-manager ; run-manager
false ; pause-requested?
false ; resume-requested?
false ; policy
(frp:new-cell false) ; exited?
(frp:event-receiver) ; exceptions
false ; main-client
empty ; clients
false ; where
false)]) ; marks
(set! all-debug-processes (cons process all-debug-processes))
process))
; Creates a debugger client
; (debug-process? require-path. -> . debug-file?)
(define (create-debug-client process modpath)
; throwaway namespace so the module-name-resolver doesn't load an unannotated module
(parameterize ([current-namespace (make-namespace)])
(let ([client (create-empty-debug-client)])
(for-each (lambda (c)
(when (equal? modpath (debug-client-modpath c))
(raise-syntax-error 'mztake:script-error:create-debug-client
(format "A client for `~a' is already defined for this process." modpath))))
(debug-process-clients process))
(set-debug-client-modpath! client modpath)
(set-debug-client-process! client process)
(set-debug-client-line-col->pos! client (line-col->pos modpath))
(set-debug-process-clients! process
(append (list client) (debug-process-clients process)))
; set the main module if it has not been set
; this implies that the first client created is always the main module
(unless (debug-process-main-client process)
(set-debug-process-main-client! process client))
client)))
(define (reqspec->modpath filename)
(define (build-module-filename str) ; taken from module-overview.ss
(let ([try (lambda (ext)
(let ([tst (string-append str ext)])
(and (file-exists? tst) tst)))])
(or (try ".ss") (try ".scm") (try "") str)))
(let ([modpath (symbol->string ((current-module-name-resolver) filename #f #f))])
(build-module-filename
(if (regexp-match #rx"^," modpath)
(substring modpath 1 (string-length modpath))
modpath))))
(define (trace* p loc thunk)
(let* ([modpath (reqspec->modpath (loc-reqspec loc))]
[client (find-client/create p modpath)]
[trace-hash (debug-client-tracepoints client)]
[trace (make-trace-struct (frp:event-receiver) thunk)]
[pos ((debug-client-line-col->pos client) (loc-line loc) (loc-col loc))])
; add the trace to the list of traces for that byte-offset
(hash-put! trace-hash pos
(append (hash-get trace-hash pos (lambda () '()))
(list trace)))
(trace-struct-evnt-rcvr trace)))
(define (syntax-local-infer-name stx)
(or (syntax-property stx 'inferred-name)
(let ([s (syntax-source stx)])
(and s
(let ([s (cond
[(path? s) (path->string s)]
[else s])]
[l (syntax-line stx)]
[c (syntax-column stx)])
(if l
(string->symbol (format "~a:~a:~a" s l c))
(let ([p (syntax-position stx)])
(string->symbol (format "~a::~a" s p)))))))))
)