1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
|
;;;; Source-paths
;;; CMUCL/SBCL use a data structure called "source-path" to locate
;;; subforms. The compiler assigns a source-path to each form in a
;;; compilation unit. Compiler notes usually contain the source-path
;;; of the error location.
;;;
;;; Compiled code objects don't contain source paths, only the
;;; "toplevel-form-number" and the (sub-) "form-number". To get from
;;; the form-number to the source-path we need the entire toplevel-form
;;; (i.e. we have to read the source code). CMUCL has already some
;;; utilities to do this translation, but we use some extended
;;; versions, because we need more exact position info. Apparently
;;; Hemlock is happy with the position of the toplevel-form; we also
;;; need the position of subforms.
;;;
;;; We use a special readtable to get the positions of the subforms.
;;; The readtable stores the start and end position for each subform in
;;; hashtable for later retrieval.
;;;
;;; This code has been placed in the Public Domain. All warranties
;;; are disclaimed.
;;; Taken from swank-cmucl.lisp, by Helmut Eller
(in-package :swank-backend)
;; Some test to ensure the required conformance
(let ((rt (copy-readtable nil)))
(assert (or (not (get-macro-character #\space rt))
(nth-value 1 (get-macro-character #\space rt))))
(assert (not (get-macro-character #\\ rt))))
(defun make-source-recorder (fn source-map)
"Return a macro character function that does the same as FN, but
additionally stores the result together with the stream positions
before and after of calling FN in the hashtable SOURCE-MAP."
(declare (type function fn))
(lambda (stream char)
(let ((start (file-position stream))
(values (multiple-value-list (funcall fn stream char)))
(end (file-position stream)))
;;(format t "[~D ~{~A~^, ~} ~D ~D]~%" start values end (char-code char))
(unless (null values)
(push (cons start end) (gethash (car values) source-map)))
(values-list values))))
(defun make-source-recording-readtable (readtable source-map)
"Return a source position recording copy of READTABLE.
The source locations are stored in SOURCE-MAP."
(let* ((tab (copy-readtable readtable))
(*readtable* tab))
(dotimes (code 128)
(let ((char (code-char code)))
(multiple-value-bind (fn term) (get-macro-character char tab)
(when fn
(set-macro-character char (make-source-recorder fn source-map)
term tab)))))
(suppress-sharp-dot tab)
tab))
(defun suppress-sharp-dot (readtable)
(when (get-macro-character #\# readtable)
(let ((sharp-dot (get-dispatch-macro-character #\# #\. readtable)))
(set-dispatch-macro-character #\# #\. (lambda (&rest args)
(let ((*read-suppress* t))
(apply sharp-dot args))
(if *read-suppress*
(values)
(list (gensym "#."))))
readtable))))
(defun read-and-record-source-map (stream)
"Read the next object from STREAM.
Return the object together with a hashtable that maps
subexpressions of the object to stream positions."
(let* ((source-map (make-hash-table :test #'eq))
(*readtable* (make-source-recording-readtable *readtable* source-map))
(start (file-position stream))
(form (read stream))
(end (file-position stream)))
;; ensure that at least FORM is in the source-map
(unless (gethash form source-map)
(push (cons start end) (gethash form source-map)))
(values form source-map)))
(defun read-source-form (n stream)
"Read the Nth toplevel form number with source location recording.
Return the form and the source-map."
(let ((*read-suppress* t))
(dotimes (i n)
(read stream)))
(let ((*read-suppress* nil)
(*read-eval* nil))
(read-and-record-source-map stream)))
(defun source-path-stream-position (path stream)
"Search the source-path PATH in STREAM and return its position."
(check-source-path path)
(destructuring-bind (tlf-number . path) path
(multiple-value-bind (form source-map) (read-source-form tlf-number stream)
(source-path-source-position (cons 0 path) form source-map))))
(defun check-source-path (path)
(unless (and (consp path)
(every #'integerp path))
(error "The source-path ~S is not valid." path)))
(defun source-path-string-position (path string)
(with-input-from-string (s string)
(source-path-stream-position path s)))
(defun source-path-file-position (path filename)
(with-open-file (file filename)
(source-path-stream-position path file)))
(defun source-path-source-position (path form source-map)
"Return the start position of PATH from FORM and SOURCE-MAP. All
subforms along the path are considered and the start and end position
of the deepest (i.e. smallest) possible form is returned."
;; compute all subforms along path
(let ((forms (loop for n in path
for f = form then (nth n f)
collect f)))
;; select the first subform present in source-map
(loop for form in (reverse forms)
for positions = (gethash form source-map)
until (and positions (null (cdr positions)))
finally (destructuring-bind ((start . end)) positions
(return (values (1- start) end))))))
|
