Add compilation regexp to match ‘dbg!’ output

While debugging tests it’s annoying when ‘compilation-mode’ matches
‘dbg!’ output incorrectly. Currently, rust-mode’s regexps assign it as
an error and incorrectly include ‘[’. The proposed change adds a
regexp to match such things and assign them info level.

Author: hron

rust-compile.el

@@ -48,6 +48,12 @@ See `compilation-error-regexp-alist' for help on their format.")
   "Specifications for matching panics in cargo test invocations.
 See `compilation-error-regexp-alist' for help on their format.")
 
+(defvar rustc-dbg!-compilation-regexps
+  (let ((re (concat "\\[" rustc-compilation-location "\\]")))
+    (cons re '(2 3 4 0 1)))
+  "Specifications for matching dbg! output.
+See `compilation-error-regexp-alist' for help on their format.")
+
 (defun rustc-scroll-down-after-next-error ()
   "In the new style error messages, the regular expression
 matches on the file name (which appears after `-->`), but the
@@ -85,6 +91,9 @@ the compilation window until the top of the error is visible."
                   (cons 'rustc-panics rustc-panics-compilation-regexps))
      (add-to-list 'compilation-error-regexp-alist 'rustc-panics)
      (add-to-list 'compilation-error-regexp-alist 'cargo)
+     (add-to-list 'compilation-error-regexp-alist-alist
+                  (cons 'rust-dbg! rustc-dbg!-compilation-regexps))
+     (add-to-list 'compilation-error-regexp-alist 'rust-dbg!)
      (add-hook 'next-error-hook #'rustc-scroll-down-after-next-error)))
 
 ;;; _

rust-mode-tests.el

@@ -3693,6 +3693,7 @@ let b = 1;"
     (insert "note: `ZZZ` could also refer to the constant imported here -> b\n  --> file4.rs:12:34\n\n")
     (insert "    ::: file5.rs:12:34\n\n")
     (insert "thread 'main' panicked at src/file7.rs:12:34:\n\n")
+    (insert "[src/file8.rs:159:5] symbol_value(SOME_VAR) = Some(\n\n")
     ;; should not match
     (insert "werror found a -> b\n  --> no_match.rs:12:34\n\n")
     (insert "error[E0061]: this function takes 1 parameter but 2 parameters were supplied\n  --> file6.rs:132:34
@@ -3712,12 +3713,14 @@ let b = 1;"
                (("file5.rs" "12" "34" compilation-info "file5.rs:12:34"))
                ((like-previous-one "82" back-to-indentation compilation-info "82")
                 (like-previous-one "132" back-to-indentation compilation-info "132"))
-               (("src/file7.rs" "12" "34" nil "src/file7.rs:12:34")))
+               (("src/file7.rs" "12" "34" nil "src/file7.rs:12:34"))
+               (("src/file8.rs" "159" "5" compilation-info "src/file8.rs:159:5")))
              (mapcar #'rust-collect-matches
                      (list rustc-compilation-regexps
                            rustc-colon-compilation-regexps
                            rustc-refs-compilation-regexps
-                           rustc-panics-compilation-regexps))))))
+                           rustc-panics-compilation-regexps
+                           rustc-dbg!-compilation-regexps))))))
 
 ;; If electric-pair-mode is available, load it and run the tests that use it.  If not,
 ;; no error--the tests will be skipped.