gnucash/libgnucash/app-utils/c-interface.scm
2017-12-20 14:55:40 +01:00

103 lines
4.2 KiB
Scheme

;; This program is free software; you can redistribute it and/or
;; modify it under the terms of the GNU General Public License as
;; published by the Free Software Foundation; either version 2 of
;; the License, or (at your option) any later version.
;;
;; This program is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;;
;; You should have received a copy of the GNU General Public License
;; along with this program; if not, contact:
;;
;; Free Software Foundation Voice: +1-617-542-5942
;; 51 Franklin Street, Fifth Floor Fax: +1-617-542-2652
;; Boston, MA 02110-1301, USA gnu@gnu.org
(define (gnc:call-with-error-handling cmd args)
(let ((captured-stack #f)
(captured-error #f)
(result #f))
(catch #t
(lambda ()
;; Execute the code in which
;; you want to catch errors here.
(if (procedure? cmd)
(set! result (apply cmd args)))
(if (string? cmd)
(set! result (eval-string cmd)))
)
(lambda (key . parameters)
;; Put the code which you want
;; to handle an error after the
;; stack has been unwound here.
(let* ((str-port (open-output-string)))
(display-backtrace captured-stack str-port)
(display "\n" str-port)
(print-exception str-port #f key parameters)
(set! captured-error (get-output-string str-port))))
(lambda (key . parameters)
;; Capture the stack here, cut the last 3 frames which are
;; make-stack, this one, and the throw handler.
(set! captured-stack (make-stack #t 3))))
(list result captured-error)
))
;; gnc:eval-string-with-error-handling will evaluate the input string (cmd)
;; an captures any exception that would be generated. It returns
;; a list with 2 elements: the output of the evaluation and a backtrace.
;; The first may be set if string evaluation did generate
;; output, the latter is set when an exception was caught.
;; We'll use this to wrap guile calls in C(++), allowing
;; the C(++) code to decide how to handle the errors.
(define (gnc:eval-string-with-error-handling cmd)
(gnc:call-with-error-handling cmd '()))
;; gnc:apply-with-error-handling will call guile's apply to run func with args
;; an captures any exception that would be generated. It returns
;; a list with 2 elements: the output of the evaluation and a backtrace.
;; The first may be set if the result of the apply did generate
;; output, the latter is set when an exception was caught.
;; We'll use this to wrap guile calls in C(++), allowing
;; the C(++) code to decide how to handle the errors.
(define (gnc:apply-with-error-handling func args)
(gnc:call-with-error-handling func args))
(define (gnc:backtrace-if-exception proc . args)
(let* ((apply-result (gnc:apply-with-error-handling proc args))
(result (car apply-result))
(error (cadr apply-result)))
(if error
(begin
(display error (current-error-port))
(if (defined? 'gnc:warn)
(gnc:warn error)))
result)))
;; This database can be used to store and retrieve translatable
;; strings. Strings that are returned by the lookup function are
;; translated with gettext.
(define (gnc:make-string-database)
(define string-hash (make-hash-table 23))
(define (lookup key)
(_ (hash-ref string-hash key)))
(define (store key string)
(hash-set! string-hash key string))
(define (dispatch message . args)
(let ((func (case message
((lookup) lookup)
((store) store)
(else #f))))
(if func
(apply func args)
(gnc:warn "string-database: bad message" message "\n"))))
dispatch)