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;;; c-snarf.scm -- Parsing documentation "snarffed" from C files.
;;;
;;; Copyright 2006-2012 Free Software Foundation, Inc.
;;;
;;;
;;; 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 3 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, write to the Free Software
;;; Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
(define-module (system documentation c-snarf)
:use-module (ice-9 popen)
:use-module (ice-9 rdelim)
:use-module (srfi srfi-13)
:use-module (srfi srfi-14)
:use-module (srfi srfi-39)
:export (run-cpp-and-extract-snarfing
parse-snarfing
parse-snarfed-line))
;;; Author: Ludovic Courts
;;;
;;; Commentary:
;;;
;;; This module provides tools to parse and otherwise manipulate
;;; documentation "snarffed" from C files, i.e., information obtained by
;;; running the C preprocessor with the @code{-DSCM_MAGIC_SNARF_DOCS} flag.
;;;
;;; Code:
;;;
;;; High-level API.
;;;
(define (run-cpp-and-extract-snarfing file cpp cpp-flags)
(let ((pipe (apply open-pipe* OPEN_READ
(cons cpp (append cpp-flags (list file))))))
(parse-snarfing pipe)))
;;;
;;; Parsing magic-snarffed CPP output.
;;;
(define (parse-c-argument-list arg-string)
"Parse @var{arg-string} (a string representing a ANSI C argument list,
e.g., @var{(const SCM first, SCM second_arg)}) and return a list of strings
denoting the argument names."
(define %c-symbol-char-set
(char-set-adjoin char-set:letter+digit #\_))
(let loop ((args (string-tokenize (string-trim-both arg-string #\space)
%c-symbol-char-set))
(type? #t)
(result '()))
(if (null? args)
(reverse! result)
(let ((the-arg (car args)))
(cond ((and type? (string=? the-arg "const"))
(loop (cdr args) type? result))
((and type? (string=? the-arg "SCM"))
(loop (cdr args) (not type?) result))
(type? ;; any other type, e.g., `void'
(loop (cdr args) (not type?) result))
(else
(loop (cdr args) (not type?) (cons the-arg result))))))))
(define (parse-documentation-item item)
"Parse @var{item} (a string), a single function string produced by the C
preprocessor. The result is an alist whose keys represent specific aspects
of a procedure's documentation: @code{c-name}, @code{scheme-name},
@code{documentation} (a Texinfo documentation string), etc."
(define (read-strings)
;; Read several subsequent strings and return their concatenation.
(let loop ((str (read))
(result '()))
(if (or (eof-object? str)
(not (string? str)))
(string-concatenate (reverse! result))
(loop (read) (cons str result)))))
(let* ((item (string-trim-both item #\space))
(space (string-index item #\space)))
(if (not space)
(error "invalid documentation item" item)
(let ((kind (substring item 0 space))
(rest (substring item space (string-length item))))
(cond ((string=? kind "cname")
(cons 'c-name (string-trim-both rest #\space)))
((string=? kind "fname")
(cons 'scheme-name
(with-input-from-string rest read-strings)))
((string=? kind "type")
(cons 'type (with-input-from-string rest read)))
((string=? kind "location")
(cons 'location
(with-input-from-string rest
(lambda ()
(let loop ((str (read))
(result '()))
(if (eof-object? str)
(reverse! result)
(loop (read) (cons str result))))))))
((string=? kind "arglist")
(cons 'arguments
(parse-c-argument-list rest)))
((string=? kind "argsig")
(cons 'signature
(with-input-from-string rest
(lambda ()
(let ((req (read)) (opt (read)) (rst? (read)))
(list (cons 'required req)
(cons 'optional opt)
(cons 'rest? (= 1 rst?))))))))
(else
;; docstring (may consist of several C strings which we
;; assume to be equivalent to Scheme strings)
(cons 'documentation
(with-input-from-string item read-strings))))))))
(define (parse-snarfed-line line)
"Parse @var{line}, a string that contains documentation returned for a
single function by the C preprocessor with the @code{-DSCM_MAGIC_SNARF_DOCS}
option. @var{line} is assumed to be a complete \"^^ { ... ^^ }\" sequence."
(define (caret-split str)
(let loop ((str str)
(result '()))
(if (string=? str "")
(reverse! result)
(let ((caret (string-index str #\^))
(len (string-length str)))
(if caret
(if (and (> (- len caret) 0)
(eq? (string-ref str (+ caret 1)) #\^))
(loop (substring str (+ 2 caret) len)
(cons (string-take str (- caret 1)) result))
(error "single caret not allowed" str))
(loop "" (cons str result)))))))
(let ((items (caret-split (substring line 4
(- (string-length line) 4)))))
(map parse-documentation-item items)))
(define (parse-snarfing port)
"Read C preprocessor (where the @code{SCM_MAGIC_SNARF_DOCS} macro is
defined) output from @var{port} a return a list of alist, each of which
contains information about a specific function described in the C
preprocessor output."
(define start-marker "^^ {")
(define end-marker "^^ }")
(define (read-snarf-lines start)
;; Read the snarf lines that follow START until and end marker is found.
(let loop ((line start)
(result '()))
(cond ((eof-object? line)
;; EOF in the middle of a "^^ { ... ^^ }" sequence; shouldn't
;; happen.
line)
((string-contains line end-marker)
=>
(lambda (end)
(let ((result (cons (string-take line (+ 3 end))
result)))
(string-concatenate-reverse result))))
((string-prefix? "#" line)
;; Presumably a "# LINENUM" directive; skip it.
(loop (read-line port) result))
(else
(loop (read-line port)
(cons line result))))))
(let loop ((line (read-line port))
(result '()))
(cond ((eof-object? line)
result)
((string-contains line start-marker)
=>
(lambda (start)
(let ((line
(read-snarf-lines (string-drop line start))))
(loop (read-line port)
(cons (parse-snarfed-line line) result)))))
(else
(loop (read-line port) result)))))
;;; c-snarf.scm ends here
;;; Local Variables:
;;; mode: scheme
;;; coding: latin-1
;;; End:
;;; arch-tag: dcba2446-ee43-46d8-a47e-e6e12f121988
|
