racket-pdb-mode: No longer use racket--module-path-name-at-point

This is, for racket-pdb-mode, in the same spirit as commit f67cccd for
racket-xp-mode.

This needs from the pdb repo commit 743c105 adding the
get-require-path function.

The back end command is now called "pdb-visit", which first tries
use->def then tries get-require-path. In other words, "visit
definition or require".

racket-pdb.el

@@ -478,57 +478,35 @@ Uses pdb to query for sites among multiple files."
   'racket-pdb-xref)
 
 (cl-defmethod xref-backend-identifier-at-point ((_backend (eql racket-pdb-xref)))
-  (or (racket--module-path-name-at-point)
-      (propertize (thing-at-point 'symbol)
-                  'racket-pdb-xref-point (point))))
+  (propertize (thing-at-point 'symbol)
+              'racket-pdb-xref-point (point)))
 
 (cl-defmethod xref-backend-identifier-completion-table ((_backend (eql racket-pdb-xref)))
   (completion-table-dynamic
    (lambda (prefix)
      (all-completions prefix racket--xp-binding-completions))))
 
 (cl-defmethod xref-backend-definitions ((_backend (eql racket-pdb-xref)) str)
-  (or
-   (pcase (get-text-property 0 'racket-module-path str)
-     (`absolute
-      (pcase (racket--cmd/await nil `(mod ,(substring-no-properties str)))
-        (`(,path ,line ,col)
-         (list (xref-make str (xref-make-file-location path line col))))))
-     (`relative
-      (let ((path (racket--rkt-or-ss-path
-                   (expand-file-name (substring-no-properties str 1 -1)))))
-        (list (xref-make str (xref-make-file-location path 1 0))))))
-
-   (pcase (racket--cmd/await nil
-                             `(pdb-use->def
-                               ,(racket-file-name-front-to-back
-                                 (racket--buffer-file-name))
-                               ,(point)))
-     (`(,path ,beg ,_end)
-      (let ((file (racket-file-name-back-to-front path)))
-        (with-current-buffer
-            (or (get-file-buffer file)
-                (let ((find-file-suppress-same-file-warnings t))
-                  (find-file-noselect file)))
-          (save-restriction
-            (widen)
-            (save-excursion
-              (goto-char beg)
-              (list (xref-make str
-                               (xref-make-file-location
-                                file
-                                (line-number-at-pos)
-                                (current-column))))))))))
-   (pcase (racket--cmd/await nil `(def ,(racket-file-name-front-to-back
-                                         (racket--buffer-file-name))
-                                       ,(substring-no-properties str)))
-     (`(,path ,line ,col)
-      (list (xref-make str
-                       (xref-make-file-location path line col))))
-     (`kernel
-      (list (xref-make str
-                       (xref-make-bogus-location
-                        "Defined in #%%kernel -- source not available")))))))
+  (pcase (racket--cmd/await nil
+                            `(pdb-visit
+                              ,(racket-file-name-front-to-back
+                                (racket--buffer-file-name))
+                              ,(point)))
+    (`(,path ,beg ,_end)
+     (let ((file (racket-file-name-back-to-front path)))
+       (with-current-buffer
+           (or (get-file-buffer file)
+               (let ((find-file-suppress-same-file-warnings t))
+                 (find-file-noselect file)))
+         (save-restriction
+           (widen)
+           (save-excursion
+             (goto-char beg)
+             (list (xref-make str
+                              (xref-make-file-location
+                               file
+                               (line-number-at-pos)
+                               (current-column)))))))))))
 
 (cl-defmethod xref-backend-references ((_backend (eql racket-pdb-xref)) str)
   (let* ((back-end-path (racket-file-name-front-to-back (racket--buffer-file-name)))

racket/command-server.rkt

@@ -23,7 +23,7 @@
 (lazy-require
  ["commands/check-syntax.rkt" (check-syntax)]
  ["commands/pdb.rkt"          (pdb-available?
-                               pdb-use->def
+                               pdb-visit
                                pdb-rename-sites
                                pdb-analyze-path
                                pdb-point-info
@@ -159,7 +159,7 @@
     [`(pdb-analyze-path ,path ,code)   (pdb-analyze-path path code)]
     [`(pdb-point-info ,path ,pos ,beg ,end) (pdb-point-info path pos beg end)]
     [`(pdb-doc-link ,path ,pos)        (pdb-doc-link path pos)]
-    [`(pdb-use->def ,path, pos)        (pdb-use->def path pos)]
+    [`(pdb-visit ,path, pos)           (pdb-visit path pos)]
     [`(pdb-rename-sites ,path ,pos)    (pdb-rename-sites path pos)]
 
     ;; Commands that MIGHT need a REPL session for context (e.g. its

racket/commands/pdb.rkt

@@ -14,7 +14,7 @@
          pdb-analyze-path
          pdb-point-info
          pdb-doc-link
-         pdb-use->def
+         pdb-visit
          pdb-rename-sites)
 
 ;;; pdb checked syntax (if available)
@@ -33,7 +33,7 @@
 
 (define-from-pdb pdb-available?
   [analyze-path get-errors get-completion-candidates
-                get-point-info get-doc-link
+                get-point-info get-doc-link get-require-path
                 use->def rename-sites])
 
 (define (pdb-analyze-path path-str code-str)
@@ -58,12 +58,12 @@
 (define (pdb-doc-link path-str pos)
   (get-doc-link (string->path path-str) pos))
 
-(define (pdb-use->def path-str pos)
-  ;; The front end xref system wants line:col not [beg end) span. :(
-  ;; Maybe pdb should change to store those, also, for arrow ends?
-  ;; Meanwhile the front end finds the line:col using find-file
-  ;; and goto-char.
-  (use->def (string->path path-str) pos))
+(define (pdb-visit path-str pos)
+  (define path (string->path path-str))
+  (or (use->def path pos)
+      (match (get-require-path path pos)
+        [(? path? req-path) (list req-path 1 2)]
+        [#f #f])))
 
 (define (pdb-rename-sites path-str pos)
   (rename-sites (string->path path-str) pos))