Merge emacs-26

8 files changed, 1806 insertions, 1205 deletions

diff --git a/lisp/progmodes/cc-engine.el b/lisp/progmodes/cc-engine.el
index 05b391a3d38..37928357526 100644
--- a/lisp/progmodes/cc-engine.el
+++ b/lisp/progmodes/cc-engine.el
@@ -132,7 +132,7 @@
 ;;
 ;;     'c-not-decl
 ;;       Put on the brace which introduces a brace list and on the commas
-;;       which separate the element within it.
+;;       which separate the elements within it.
 ;;
 ;; 'c-awk-NL-prop
 ;;   Used in AWK mode to mark the various kinds of newlines.  See
@@ -5403,15 +5403,14 @@ comment at the start of cc-engine.el for more info."
 	(min c-bs-cache-limit pos)))
 
 (defun c-update-brace-stack (stack from to)
-  ;; Give a brace-stack which has the value STACK at position FROM, update it
-  ;; to it's value at position TO, where TO is after (or equal to) FROM.
+  ;; Given a brace-stack which has the value STACK at position FROM, update it
+  ;; to its value at position TO, where TO is after (or equal to) FROM.
   ;; Return a cons of either TO (if it is outside a literal) and this new
   ;; value, or of the next position after TO outside a literal and the new
   ;; value.
   (let (match kwd-sym (prev-match-pos 1)
 	      (s (cdr stack))
-	      (bound-<> (car stack))
-	      )
+	      (bound-<> (car stack)))
     (save-excursion
       (cond
        ((and bound-<> (<= to bound-<>))
@@ -5472,6 +5471,9 @@ comment at the start of cc-engine.el for more info."
 	    (setq s (cdr s))))
 	 ((c-keyword-member kwd-sym 'c-flat-decl-block-kwds)
 	  (push 0 s))))
+      ;; The failing `c-syntactic-re-search-forward' may have left us in the
+      ;; middle of a token, which might be a significant token.  Fix this!
+      (c-beginning-of-current-token)
       (cons (point)
 	    (cons bound-<> s)))))
 
@@ -5647,11 +5649,13 @@ comment at the start of cc-engine.el for more info."
   ;; Call CFD-FUN for each possible spot for a declaration, cast or
   ;; label from the point to CFD-LIMIT.
   ;;
-  ;; CFD-FUN is called with point at the start of the spot.  It's passed two
+  ;; CFD-FUN is called with point at the start of the spot.  It's passed three
   ;; arguments: The first is the end position of the token preceding the spot,
   ;; or 0 for the implicit match at bob.  The second is a flag that is t when
-  ;; the match is inside a macro.  Point should be moved forward by at least
-  ;; one token.
+  ;; the match is inside a macro.  The third is a flag that is t when the
+  ;; match is at "top level", i.e. outside any brace block, or directly inside
+  ;; a class or namespace, etc.  Point should be moved forward by at least one
+  ;; token.
   ;;
   ;; If CFD-FUN adds `c-decl-end' properties somewhere below the current spot,
   ;; it should return non-nil to ensure that the next search will find them.
@@ -6038,6 +6042,8 @@ comment at the start of cc-engine.el for more info."
 		   (setq cfd-macro-end 0)
 		   nil))))		; end of when condition
 
+	(when (> cfd-macro-end 0)
+	  (setq cfd-top-level nil))	; In a macro is "never" at top level.
 	(c-debug-put-decl-spot-faces cfd-match-pos (point))
 	(if (funcall cfd-fun cfd-match-pos (/= cfd-macro-end 0) cfd-top-level)
 	    (setq cfd-prop-match nil))
@@ -8575,7 +8581,13 @@ comment at the start of cc-engine.el for more info."
 		 (looking-at c-noise-macro-with-parens-name-re))
 	    (c-forward-noise-clause))
 
-	   ((looking-at c-type-decl-suffix-key)
+	   ((and (looking-at c-type-decl-suffix-key)
+		 ;; We avoid recognizing foo(bar) or foo() at top level as a
+		 ;; construct here in C, since we want to recognize this as a
+		 ;; typeless function declaration.
+		 (not (and (c-major-mode-is 'c-mode)
+			   (eq context 'top)
+			   (eq (char-after) ?\)))))
 	    (if (eq (char-after) ?\))
 		(when (> paren-depth 0)
 		  (setq paren-depth (1- paren-depth))
@@ -8618,7 +8630,12 @@ comment at the start of cc-engine.el for more info."
 				     (save-excursion
 				       (goto-char after-paren-pos)
 				       (c-forward-syntactic-ws)
-				       (c-forward-type)))))
+				       (or (c-forward-type)
+					   ;; Recognize a top-level typeless
+					   ;; function declaration in C.
+					   (and (c-major-mode-is 'c-mode)
+						(eq context 'top)
+						(eq (char-after) ?\))))))))
 			  (setq pos (c-up-list-forward (point)))
 			  (eq (char-before pos) ?\)))
 		 (c-fdoc-shift-type-backward)
@@ -9035,9 +9052,12 @@ comment at the start of cc-engine.el for more info."
 	 ;; (in at least C++) that anything that can be parsed as a declaration
 	 ;; is a declaration.  Now we're being more defensive and prefer to
 	 ;; highlight things like "foo (bar);" as a declaration only if we're
-	 ;; inside an arglist that contains declarations.
-         ;; CASE 19
-	 (eq context 'decl))))
+	 ;; inside an arglist that contains declarations.  Update (2017-09): We
+	 ;; now recognize a top-level "foo(bar);" as a declaration in C.
+	 ;; CASE 19
+	 (or (eq context 'decl)
+	     (and (c-major-mode-is 'c-mode)
+		  (eq context 'top))))))
 
     ;; The point is now after the type decl expression.
 
@@ -9545,6 +9565,7 @@ Note that this function might do hidden buffer changes.  See the
 comment at the start of cc-engine.el for more info."
   ;; Note to maintainers: this function consumes a great mass of CPU cycles.
   ;; Its use should thus be minimized as far as possible.
+  ;; Consider instead using `c-bs-at-toplevel-p'.
   (let ((paren-state (c-parse-state)))
     (or (not (c-most-enclosing-brace paren-state))
 	(c-search-uplist-for-classkey paren-state))))
@@ -9574,8 +9595,15 @@ comment at the start of cc-engine.el for more info."
      (not (and (c-major-mode-is 'objc-mode)
 	       (c-forward-objc-directive)))
 
+     ;; Don't confuse #if .... defined(foo) for a function arglist.
+     (not (and (looking-at c-cpp-expr-functions-key)
+	       (save-excursion
+		 (save-restriction
+		   (widen)
+		   (c-beginning-of-macro lim)))))
      (setq id-start
 	   (car-safe (c-forward-decl-or-cast-1 (c-point 'bosws) 'top nil)))
+     (numberp id-start)
      (< id-start beg)
 
      ;; There should not be a '=' or ',' between beg and the
diff --git a/lisp/progmodes/cc-langs.el b/lisp/progmodes/cc-langs.el
index 9495d602e09..227b3e16485 100644
--- a/lisp/progmodes/cc-langs.el
+++ b/lisp/progmodes/cc-langs.el
@@ -952,6 +952,11 @@ expression, or nil if there aren't any in the language."
 	   '("defined"))
   pike '("defined" "efun" "constant"))
 
+(c-lang-defconst c-cpp-expr-functions-key
+  ;; Matches a function in a cpp expression.
+  t (c-make-keywords-re t (c-lang-const c-cpp-expr-functions)))
+(c-lang-defvar c-cpp-expr-functions-key (c-lang-const c-cpp-expr-functions-key))
+
 (c-lang-defconst c-assignment-operators
   "List of all assignment operators."
   t    '("=" "*=" "/=" "%=" "+=" "-=" ">>=" "<<=" "&=" "^=" "|=")
diff --git a/lisp/progmodes/cc-mode.el b/lisp/progmodes/cc-mode.el
index 8867453e85c..b0e5fe47a7c 100644
--- a/lisp/progmodes/cc-mode.el
+++ b/lisp/progmodes/cc-mode.el
@@ -1571,6 +1571,8 @@ Note that this is a strict tail, so won't match, e.g. \"0x....\".")
 		   (and (c-beginning-of-macro)
 			(progn (c-end-of-macro) (point))))))
 	(when (and (c-forward-declarator lim)
+		   (or (not (eq (char-after) ?\())
+		       (c-go-list-forward nil lim))
 		   (eq (c-forward-token-2 1 nil lim) 0))
 	  (c-backward-syntactic-ws)
 	  (point))))))
@@ -1589,7 +1591,7 @@ Note that this is a strict tail, so won't match, e.g. \"0x....\".")
 	    (or (c-fl-decl-start c-new-BEG) (c-point 'bol c-new-BEG))
 	    c-new-END
 	    (or (c-fl-decl-end c-new-END)
-		(c-point 'bonl (max (1- c-new-END) (point-min)))))))
+		(c-point 'bonl c-new-END)))))
 
 (defun c-context-expand-fl-region (beg end)
   ;; Return a cons (NEW-BEG . NEW-END), where NEW-BEG is the beginning of a
diff --git a/lisp/progmodes/elisp-mode.el b/lisp/progmodes/elisp-mode.el
index 2f8e081a295..3690f673832 100644
--- a/lisp/progmodes/elisp-mode.el
+++ b/lisp/progmodes/elisp-mode.el
@@ -243,7 +243,9 @@ Blank lines separate paragraphs.  Semicolons start comments.
   (add-hook 'xref-backend-functions #'elisp--xref-backend nil t)
   (setq-local project-vc-external-roots-function #'elisp-load-path-roots)
   (add-hook 'completion-at-point-functions
-            #'elisp-completion-at-point nil 'local))
+            #'elisp-completion-at-point nil 'local)
+  (add-hook 'flymake-diagnostic-functions #'elisp-flymake-checkdoc nil t)
+  (add-hook 'flymake-diagnostic-functions #'elisp-flymake-byte-compile nil t))
 
 ;; Font-locking support.
 
@@ -810,7 +812,7 @@ non-nil result supercedes the xrefs produced by
   (apply #'nconc
          (let (lst)
            (dolist (sym (apropos-internal regexp))
-            (push (elisp--xref-find-definitions sym) lst))
+             (push (elisp--xref-find-definitions sym) lst))
            (nreverse lst))))
 
 (defvar elisp--xref-identifier-completion-table
@@ -1109,7 +1111,7 @@ If CHAR is not a character, return nil."
           ;; interactive call would use it.
           ;; FIXME: Is it really the right place for this?
           (when (eq (car-safe expr) 'interactive)
-	       (setq expr
+	    (setq expr
                   `(call-interactively
                     (lambda (&rest args) ,expr args))))
 	  expr)))))
@@ -1174,7 +1176,7 @@ POS specifies the starting position where EXP was found and defaults to point."
             (and (not (special-variable-p var))
                  (save-excursion
                    (zerop (car (syntax-ppss (match-beginning 0)))))
-              (push var vars))))
+                 (push var vars))))
         `(progn ,@(mapcar (lambda (v) `(defvar ,v)) vars) ,exp)))))
 
 (defun eval-last-sexp (eval-last-sexp-arg-internal)
@@ -1379,7 +1381,7 @@ or elsewhere, return a 1-line docstring."
 		    (t (help-function-arglist sym)))))
              ;; Stringify, and store before highlighting, downcasing, etc.
 	     (elisp--last-data-store sym (elisp-function-argstring args)
-                                    'function))))))
+                                     'function))))))
     ;; Highlight, truncate.
     (if argstring
 	(elisp--highlight-function-argument
@@ -1588,5 +1590,164 @@ ARGLIST is either a string, or a list of strings or symbols."
         (replace-match "(" t t str)
       str)))
 
+;;; Flymake support
+
+;; Don't require checkdoc, but forward declare these checkdoc special
+;; variables. Autoloading them on `checkdoc-current-buffer' is too
+;; late, they won't be bound dynamically.
+(defvar checkdoc-create-error-function)
+(defvar checkdoc-autofix-flag)
+(defvar checkdoc-generate-compile-warnings-flag)
+(defvar checkdoc-diagnostic-buffer)
+(defun elisp-flymake--checkdoc-1 ()
+  "Do actual work for `elisp-flymake-checkdoc'."
+  (let (collected)
+    (let* ((checkdoc-create-error-function
+            (lambda (text start end &optional unfixable)
+              (push (list text start end unfixable) collected)
+              nil))
+           (checkdoc-autofix-flag nil)
+           (checkdoc-generate-compile-warnings-flag nil)
+           (buf (generate-new-buffer " *checkdoc-temp*"))
+           (checkdoc-diagnostic-buffer buf))
+      (unwind-protect
+          (save-excursion
+            (checkdoc-current-buffer t))
+        (kill-buffer buf)))
+    collected))
+
+;;;###autoload
+(defun elisp-flymake-checkdoc (report-fn &rest _args)
+  "A Flymake backend for `checkdoc'.
+Calls REPORT-FN directly."
+  (unless (derived-mode-p 'emacs-lisp-mode)
+    (error "Can only work on `emacs-lisp-mode' buffers"))
+  (funcall report-fn
+           (cl-loop for (text start end _unfixable) in
+                    (elisp-flymake--checkdoc-1)
+                    collect
+                    (flymake-make-diagnostic
+                     (current-buffer)
+                     start end :note text))))
+
+(defun elisp-flymake--byte-compile-done (report-fn
+                                         origin-buffer
+                                         output-buffer
+                                         temp-file)
+  (unwind-protect
+      (with-current-buffer
+          origin-buffer
+        (save-excursion
+          (save-restriction
+            (widen)
+            (funcall
+             report-fn
+             (cl-loop with data =
+                      (with-current-buffer output-buffer
+                        (goto-char (point-min))
+                        (search-forward ":elisp-flymake-output-start")
+                        (read (point-marker)))
+                      for (string pos _fill level) in data
+                      do (goto-char pos)
+                      for beg = (if (< (point) (point-max))
+                                    (point)
+                                  (line-beginning-position))
+                      for end = (min
+                                 (line-end-position)
+                                 (or (cdr
+                                      (bounds-of-thing-at-point 'sexp))
+                                     (point-max)))
+                      collect (flymake-make-diagnostic
+                               (current-buffer)
+                               (if (= beg end) (1- beg) beg)
+                               end
+                               level
+                               string))))))
+    (kill-buffer output-buffer)
+    (ignore-errors (delete-file temp-file))))
+
+(defvar-local elisp-flymake--byte-compile-process nil
+  "Buffer-local process started for byte-compiling the buffer.")
+
+;;;###autoload
+(defun elisp-flymake-byte-compile (report-fn &rest _args)
+  "A Flymake backend for elisp byte compilation.
+Spawn an Emacs process that byte-compiles a file representing the
+current buffer state and calls REPORT-FN when done."
+  (interactive (list (lambda (stuff)
+                       (message "aha %s" stuff))))
+  (unless (derived-mode-p 'emacs-lisp-mode)
+    (error "Can only work on `emacs-lisp-mode' buffers"))
+  (when elisp-flymake--byte-compile-process
+    (process-put elisp-flymake--byte-compile-process 'elisp-flymake--obsolete t)
+    (when (process-live-p elisp-flymake--byte-compile-process)
+      (kill-process elisp-flymake--byte-compile-process)))
+  (let ((temp-file (make-temp-file "elisp-flymake-byte-compile"))
+        (origin-buffer (current-buffer)))
+    (save-restriction
+      (widen)
+      (write-region (point-min) (point-max) temp-file nil 'nomessage))
+    (let* ((output-buffer (generate-new-buffer " *elisp-flymake-byte-compile*")))
+      (setq
+       elisp-flymake--byte-compile-process
+       (make-process
+        :name "elisp-flymake-byte-compile"
+        :buffer output-buffer
+        :command (list (expand-file-name invocation-name invocation-directory)
+                       "-Q"
+                       "--batch"
+                       ;; "--eval" "(setq load-prefer-newer t)" ; for testing
+                       "-L" default-directory
+                       "-f" "elisp-flymake--batch-compile-for-flymake"
+                       temp-file)
+        :connection-type 'pipe
+        :sentinel
+        (lambda (proc _event)
+          (unless (process-live-p proc)
+            (unwind-protect
+                (cond
+                 ((zerop (process-exit-status proc))
+                  (elisp-flymake--byte-compile-done report-fn
+                                                    origin-buffer
+                                                    output-buffer
+                                                    temp-file))
+                 ((process-get proc 'elisp-flymake--obsolete)
+                  (flymake-log :warning "byte-compile process %s obsolete" proc))
+                 (t
+                  (funcall report-fn
+                           :panic
+                           :explanation
+                           (format "byte-compile process %s died" proc)))))))))
+      :stderr null-device
+      :noquery t)))
+
+(defun elisp-flymake--batch-compile-for-flymake (&optional file)
+  "Helper for `elisp-flymake-byte-compile'.
+Runs in a batch-mode Emacs.  Interactively use variable
+`buffer-file-name' for FILE."
+  (interactive (list buffer-file-name))
+  (let* ((file (or file
+                   (car command-line-args-left)))
+         (dummy-elc-file)
+         (byte-compile-log-buffer
+          (generate-new-buffer " *dummy-byte-compile-log-buffer*"))
+         (byte-compile-dest-file-function
+          (lambda (source)
+            (setq dummy-elc-file (make-temp-file (file-name-nondirectory source)))))
+         (collected)
+         (byte-compile-log-warning-function
+          (lambda (string &optional position fill level)
+            (push (list string position fill level)
+                  collected)
+            t)))
+    (unwind-protect
+        (byte-compile-file file)
+      (ignore-errors
+        (delete-file dummy-elc-file)
+        (kill-buffer byte-compile-log-buffer)))
+    (prin1 :elisp-flymake-output-start)
+    (terpri)
+    (pp collected)))
+
 (provide 'elisp-mode)
 ;;; elisp-mode.el ends here
diff --git a/lisp/progmodes/flymake-proc.el b/lisp/progmodes/flymake-proc.el
index df1a0750cfb..52cb1985327 100644
--- a/lisp/progmodes/flymake-proc.el
+++ b/lisp/progmodes/flymake-proc.el
@@ -1,4 +1,4 @@
-;;; flymake-proc.el --- Flymake for external syntax checker processes  -*- lexical-binding: t; -*-
+;;; flymake-proc.el --- Flymake backend for external tools  -*- lexical-binding: t; -*-
 
 ;; Copyright (C) 2003-2017 Free Software Foundation, Inc.
 
@@ -20,15 +20,19 @@
 ;; GNU General Public License for more details.
 
 ;; You should have received a copy of the GNU General Public License
-;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
+;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
 
 ;;; Commentary:
 ;;
 ;; Flymake is a minor Emacs mode performing on-the-fly syntax checks.
 ;;
-;; This file contains the most original implementation of flymake's
-;; main source of on-the-fly diagnostic info, the external syntax
-;; checker backend.
+;; This file contains a significant part of the original flymake's
+;; implementation, a buffer-checking mechanism that parses the output
+;; of an external syntax check tool with regular expressions.
+;;
+;; That work has been adapted into a flymake "backend" function,
+;; `flymake-proc-legacy-flymake' suitable for adding to the
+;; `flymake-diagnostic-functions' variable.
 ;;
 ;;; Bugs/todo:
 
@@ -37,42 +41,45 @@
 
 ;;; Code:
 
-(require 'flymake-ui)
+(require 'flymake)
 
-(defcustom flymake-compilation-prevents-syntax-check t
+(defcustom flymake-proc-compilation-prevents-syntax-check t
   "If non-nil, don't start syntax check if compilation is running."
   :group 'flymake
   :type 'boolean)
 
-(defcustom flymake-xml-program
+(defcustom flymake-proc-xml-program
   (if (executable-find "xmlstarlet") "xmlstarlet" "xml")
   "Program to use for XML validation."
   :type 'file
   :group 'flymake
   :version "24.4")
 
-(defcustom flymake-master-file-dirs '("." "./src" "./UnitTest")
+(defcustom flymake-proc-master-file-dirs '("." "./src" "./UnitTest")
   "Dirs where to look for master files."
   :group 'flymake
   :type '(repeat (string)))
 
-(defcustom flymake-master-file-count-limit 32
+(defcustom flymake-proc-master-file-count-limit 32
   "Max number of master files to check."
   :group 'flymake
   :type 'integer)
 
-(defcustom flymake-allowed-file-name-masks
-  '(("\\.\\(?:c\\(?:pp\\|xx\\|\\+\\+\\)?\\|CC\\)\\'" flymake-simple-make-init)
-    ("\\.xml\\'" flymake-xml-init)
-    ("\\.html?\\'" flymake-xml-init)
-    ("\\.cs\\'" flymake-simple-make-init)
-    ("\\.p[ml]\\'" flymake-perl-init)
-    ("\\.php[345]?\\'" flymake-php-init)
-    ("\\.h\\'" flymake-master-make-header-init flymake-master-cleanup)
-    ("\\.java\\'" flymake-simple-make-java-init flymake-simple-java-cleanup)
-    ("[0-9]+\\.tex\\'" flymake-master-tex-init flymake-master-cleanup)
-    ("\\.tex\\'" flymake-simple-tex-init)
-    ("\\.idl\\'" flymake-simple-make-init)
+(defcustom flymake-proc-allowed-file-name-masks
+  '(("\\.\\(?:c\\(?:pp\\|xx\\|\\+\\+\\)?\\|CC\\)\\'"
+     flymake-proc-simple-make-init
+     nil
+     flymake-proc-real-file-name-considering-includes)
+    ("\\.xml\\'" flymake-proc-xml-init)
+    ("\\.html?\\'" flymake-proc-xml-init)
+    ("\\.cs\\'" flymake-proc-simple-make-init)
+    ("\\.p[ml]\\'" flymake-proc-perl-init)
+    ("\\.php[345]?\\'" flymake-proc-php-init)
+    ("\\.h\\'" flymake-proc-master-make-header-init flymake-proc-master-cleanup)
+    ("\\.java\\'" flymake-proc-simple-make-java-init flymake-proc-simple-java-cleanup)
+    ("[0-9]+\\.tex\\'" flymake-proc-master-tex-init flymake-proc-master-cleanup)
+    ("\\.tex\\'" flymake-proc-simple-tex-init)
+    ("\\.idl\\'" flymake-proc-simple-make-init)
     ;; ("\\.cpp\\'" 1)
     ;; ("\\.java\\'" 3)
     ;; ("\\.h\\'" 2 ("\\.cpp\\'" "\\.c\\'")
@@ -85,98 +92,161 @@
     )
   "Files syntax checking is allowed for.
 This is an alist with elements of the form:
-  REGEXP [INIT [CLEANUP [NAME]]]
+  REGEXP INIT [CLEANUP [NAME]]
 REGEXP is a regular expression that matches a file name.
-INIT is the init function to use, missing means disable `flymake-mode'.
-CLEANUP is the cleanup function to use, default `flymake-simple-cleanup'.
-NAME is the file name function to use, default `flymake-get-real-file-name'."
+INIT is the init function to use.
+CLEANUP is the cleanup function to use, default `flymake-proc-simple-cleanup'.
+NAME is the file name function to use, default `flymake-proc-get-real-file-name'."
   :group 'flymake
   :type '(alist :key-type (regexp :tag "File regexp")
                 :value-type
                 (list :tag "Handler functions"
-                      (choice :tag "Init function"
-                              (const :tag "disable" nil)
-                              function)
+                      (function :tag "Init function")
                       (choice :tag "Cleanup function"
-                              (const :tag "flymake-simple-cleanup" nil)
+                              (const :tag "flymake-proc-simple-cleanup" nil)
                               function)
                       (choice :tag "Name function"
-                              (const :tag "flymake-get-real-file-name" nil)
+                              (const :tag "flymake-proc-get-real-file-name" nil)
                               function))))
 
-(defvar flymake-processes nil
-  "List of currently active flymake processes.")
+(defvar-local flymake-proc--current-process nil
+  "Currently active Flymake process for a buffer, if any.")
+
+(defvar flymake-proc--report-fn nil
+  "If bound, function used to report back to Flymake's UI.")
+
+(defun flymake-proc-reformat-err-line-patterns-from-compile-el (original-list)
+  "Grab error line patterns from ORIGINAL-LIST in compile.el format.
+Convert it to Flymake internal format."
+  (let* ((converted-list '()))
+    (dolist (item original-list)
+      (setq item (cdr item))
+      (let ((regexp (nth 0 item))
+	    (file (nth 1 item))
+	    (line (nth 2 item))
+	    (col (nth 3 item)))
+	(if (consp file)	(setq file (car file)))
+	(if (consp line)	(setq line (car line)))
+	(if (consp col)	(setq col (car col)))
 
-(defvar-local flymake-output-residual nil)
+	(when (not (functionp line))
+	  (setq converted-list (cons (list regexp file line col) converted-list)))))
+    converted-list))
 
-(defun flymake-get-file-name-mode-and-masks (file-name)
-  "Return the corresponding entry from `flymake-allowed-file-name-masks'."
+(defvar flymake-proc-err-line-patterns ; regexp file-idx line-idx col-idx (optional) text-idx(optional), match-end to end of string is error text
+  (append
+   '(
+     ;; MS Visual C++ 6.0
+     ("\\(\\([a-zA-Z]:\\)?[^:(\t\n]+\\)(\\([0-9]+\\)) : \\(\\(error\\|warning\\|fatal error\\) \\(C[0-9]+\\):[ \t\n]*\\(.+\\)\\)"
+      1 3 nil 4)
+     ;; jikes
+     ("\\(\\([a-zA-Z]:\\)?[^:(\t\n]+\\):\\([0-9]+\\):[0-9]+:[0-9]+:[0-9]+: \\(\\(Error\\|Warning\\|Caution\\|Semantic Error\\):[ \t\n]*\\(.+\\)\\)"
+      1 3 nil 4)
+     ;; MS midl
+     ("midl[ ]*:[ ]*\\(command line error .*\\)"
+      nil nil nil 1)
+     ;; MS C#
+     ("\\(\\([a-zA-Z]:\\)?[^:(\t\n]+\\)(\\([0-9]+\\),[0-9]+): \\(\\(error\\|warning\\|fatal error\\) \\(CS[0-9]+\\):[ \t\n]*\\(.+\\)\\)"
+      1 3 nil 4)
+     ;; perl
+     ("\\(.*\\) at \\([^ \n]+\\) line \\([0-9]+\\)[,.\n]" 2 3 nil 1)
+     ;; PHP
+     ("\\(?:Parse\\|Fatal\\) error: \\(.*\\) in \\(.*\\) on line \\([0-9]+\\)" 2 3 nil 1)
+     ;; LaTeX warnings (fileless) ("\\(LaTeX \\(Warning\\|Error\\): .*\\) on input line \\([0-9]+\\)" 20 3 nil 1)
+     ;; ant/javac.  Note this also matches gcc warnings!
+     (" *\\(\\[javac\\] *\\)?\\(\\([a-zA-Z]:\\)?[^:(\t\n]+\\):\\([0-9]+\\)\\(?::\\([0-9]+\\)\\)?:[ \t\n]*\\(.+\\)"
+      2 4 5 6))
+   ;; compilation-error-regexp-alist)
+   (flymake-proc-reformat-err-line-patterns-from-compile-el compilation-error-regexp-alist-alist))
+  "Patterns for matching error/warning lines.  Each pattern has the form
+\(REGEXP FILE-IDX LINE-IDX COL-IDX ERR-TEXT-IDX).
+Use `flymake-proc-reformat-err-line-patterns-from-compile-el' to add patterns
+from compile.el")
+
+(define-obsolete-variable-alias 'flymake-warning-re 'flymake-proc-diagnostic-type-pred "26.1")
+(defvar flymake-proc-diagnostic-type-pred
+  'flymake-proc-default-guess
+  "Predicate matching against diagnostic text to detect its type.
+Takes a single argument, the diagnostic's text and should return
+a value suitable for indexing
+`flymake-diagnostic-types-alist' (which see). If the returned
+value is nil, a type of `:error' is assumed. For some backward
+compatibility, if a non-nil value is returned that that doesn't
+index that alist, a type of `:warning' is assumed.
+
+Instead of a function, it can also be a string, a regular
+expression. A match indicates `:warning' type, otherwise
+`:error'")
+
+(defun flymake-proc-default-guess (text)
+  "Guess if TEXT means a warning, a note or an error."
+  (cond ((string-match "^[wW]arning" text)
+         :warning)
+        ((string-match "^[nN]ote" text)
+         :note)
+        (t
+         :error)))
+
+(defun flymake-proc--get-file-name-mode-and-masks (file-name)
+  "Return the corresponding entry from `flymake-proc-allowed-file-name-masks'."
   (unless (stringp file-name)
     (error "Invalid file-name"))
-  (let ((fnm flymake-allowed-file-name-masks)
+  (let ((fnm flymake-proc-allowed-file-name-masks)
 	(mode-and-masks nil))
     (while (and (not mode-and-masks) fnm)
-      (let ((item (pop fnm)))
-        (when (string-match (car item) file-name)
-	  (setq mode-and-masks item)))) ; (cdr item) may be nil
-    (setq mode-and-masks (cdr mode-and-masks))
+      (if (string-match (car (car fnm)) file-name)
+	  (setq mode-and-masks (cdr (car fnm))))
+      (setq fnm (cdr fnm)))
     (flymake-log 3 "file %s, init=%s" file-name (car mode-and-masks))
     mode-and-masks))
 
-(defun flymake-proc-can-syntax-check-buffer ()
-  "Determine whether we can syntax check current buffer.
-Return nil if we cannot, non-nil if
-we can."
-  (and buffer-file-name
-       (if (flymake-get-init-function buffer-file-name) t nil)))
-
-(defun flymake-get-init-function (file-name)
+(defun flymake-proc--get-init-function (file-name)
   "Return init function to be used for the file."
-  (let* ((init-f  (nth 0 (flymake-get-file-name-mode-and-masks file-name))))
+  (let* ((init-f  (nth 0 (flymake-proc--get-file-name-mode-and-masks file-name))))
     ;;(flymake-log 0 "calling %s" init-f)
     ;;(funcall init-f (current-buffer))
     init-f))
 
-(defun flymake-get-cleanup-function (file-name)
+(defun flymake-proc--get-cleanup-function (file-name)
   "Return cleanup function to be used for the file."
-  (or (nth 1 (flymake-get-file-name-mode-and-masks file-name))
-      'flymake-simple-cleanup))
+  (or (nth 1 (flymake-proc--get-file-name-mode-and-masks file-name))
+      'flymake-proc-simple-cleanup))
 
-(defun flymake-get-real-file-name-function (file-name)
-  (or (nth 2 (flymake-get-file-name-mode-and-masks file-name))
-      'flymake-get-real-file-name))
+(defun flymake-proc--get-real-file-name-function (file-name)
+  (or (nth 2 (flymake-proc--get-file-name-mode-and-masks file-name))
+      'flymake-proc-get-real-file-name))
 
-(defvar flymake-find-buildfile-cache (make-hash-table :test #'equal))
+(defvar flymake-proc--find-buildfile-cache (make-hash-table :test #'equal))
 
-(defun flymake-get-buildfile-from-cache (dir-name)
+(defun flymake-proc--get-buildfile-from-cache (dir-name)
   "Look up DIR-NAME in cache and return its associated value.
 If DIR-NAME is not found, return nil."
-  (gethash dir-name flymake-find-buildfile-cache))
+  (gethash dir-name flymake-proc--find-buildfile-cache))
 
-(defun flymake-add-buildfile-to-cache (dir-name buildfile)
+(defun flymake-proc--add-buildfile-to-cache (dir-name buildfile)
   "Associate DIR-NAME with BUILDFILE in the buildfile cache."
-  (puthash dir-name buildfile flymake-find-buildfile-cache))
+  (puthash dir-name buildfile flymake-proc--find-buildfile-cache))
 
-(defun flymake-clear-buildfile-cache ()
+(defun flymake-proc--clear-buildfile-cache ()
   "Clear the buildfile cache."
-  (clrhash flymake-find-buildfile-cache))
+  (clrhash flymake-proc--find-buildfile-cache))
 
-(defun flymake-find-buildfile (buildfile-name source-dir-name)
+(defun flymake-proc--find-buildfile (buildfile-name source-dir-name)
   "Find buildfile starting from current directory.
 Buildfile includes Makefile, build.xml etc.
 Return its file name if found, or nil if not found."
-  (or (flymake-get-buildfile-from-cache source-dir-name)
+  (or (flymake-proc--get-buildfile-from-cache source-dir-name)
       (let* ((file (locate-dominating-file source-dir-name buildfile-name)))
         (if file
             (progn
               (flymake-log 3 "found buildfile at %s" file)
-              (flymake-add-buildfile-to-cache source-dir-name file)
+              (flymake-proc--add-buildfile-to-cache source-dir-name file)
               file)
           (progn
             (flymake-log 3 "buildfile for %s not found" source-dir-name)
             nil)))))
 
-(defun flymake-fix-file-name (name)
+(defun flymake-proc--fix-file-name (name)
   "Replace all occurrences of `\\' with `/'."
   (when name
     (setq name (expand-file-name name))
@@ -184,18 +254,17 @@ Return its file name if found, or nil if not found."
     (setq name (directory-file-name name))
     name))
 
-(defun flymake-same-files (file-name-one file-name-two)
+(defun flymake-proc--same-files (file-name-one file-name-two)
   "Check if FILE-NAME-ONE and FILE-NAME-TWO point to same file.
 Return t if so, nil if not."
-  (equal (flymake-fix-file-name file-name-one)
-	 (flymake-fix-file-name file-name-two)))
+  (equal (flymake-proc--fix-file-name file-name-one)
+	 (flymake-proc--fix-file-name file-name-two)))
 
 ;; This is bound dynamically to pass a parameter to a sort predicate below
-(defvar flymake-included-file-name)
+(defvar flymake-proc--included-file-name)
 
-(defun flymake-find-possible-master-files (file-name master-file-dirs masks)
+(defun flymake-proc--find-possible-master-files (file-name master-file-dirs masks)
   "Find (by name and location) all possible master files.
-
 Name is specified by FILE-NAME and location is specified by
 MASTER-FILE-DIRS.  Master files include .cpp and .c for .h.
 Files are searched for starting from the .h directory and max
@@ -216,35 +285,35 @@ max-level parent dirs.  File contents are not checked."
 	    (while (and (not done) dir-files)
 	      (when (not (file-directory-p (car dir-files)))
 		(setq files (cons (car dir-files) files))
-		(when (>= (length files) flymake-master-file-count-limit)
-		  (flymake-log 3 "master file count limit (%d) reached" flymake-master-file-count-limit)
+		(when (>= (length files) flymake-proc-master-file-count-limit)
+		  (flymake-log 3 "master file count limit (%d) reached" flymake-proc-master-file-count-limit)
 		  (setq done t)))
 	      (setq dir-files (cdr dir-files))))
 	  (setq masks (cdr masks))))
       (setq dirs (cdr dirs)))
     (when files
-      (let ((flymake-included-file-name (file-name-nondirectory file-name)))
-	(setq files (sort files 'flymake-master-file-compare))))
+      (let ((flymake-proc--included-file-name (file-name-nondirectory file-name)))
+	(setq files (sort files 'flymake-proc--master-file-compare))))
     (flymake-log 3 "found %d possible master file(s)" (length files))
     files))
 
-(defun flymake-master-file-compare (file-one file-two)
+(defun flymake-proc--master-file-compare (file-one file-two)
   "Compare two files specified by FILE-ONE and FILE-TWO.
 This function is used in sort to move most possible file names
 to the beginning of the list (File.h -> File.cpp moved to top)."
-  (and (equal (file-name-sans-extension flymake-included-file-name)
+  (and (equal (file-name-sans-extension flymake-proc--included-file-name)
 	      (file-name-base file-one))
        (not (equal file-one file-two))))
 
-(defvar flymake-check-file-limit 8192
+(defvar flymake-proc-check-file-limit 8192
   "Maximum number of chars to look at when checking possible master file.
 Nil means search the entire file.")
 
-(defun flymake-check-patch-master-file-buffer
-       (master-file-temp-buffer
-        master-file-name patched-master-file-name
-        source-file-name patched-source-file-name
-        include-dirs regexp)
+(defun flymake-proc--check-patch-master-file-buffer
+    (master-file-temp-buffer
+     master-file-name patched-master-file-name
+     source-file-name patched-source-file-name
+     include-dirs regexp)
   "Check if MASTER-FILE-NAME is a master file for SOURCE-FILE-NAME.
 If yes, patch a copy of MASTER-FILE-NAME to include PATCHED-SOURCE-FILE-NAME
 instead of SOURCE-FILE-NAME.
@@ -258,7 +327,7 @@ instead of reading master file from disk."
          (source-file-nonext (file-name-sans-extension source-file-nondir))
          (found                     nil)
 	 (inc-name                  nil)
-	 (search-limit              flymake-check-file-limit))
+	 (search-limit              flymake-proc-check-file-limit))
     (setq regexp
           (format regexp	; "[ \t]*#[ \t]*include[ \t]*\"\\(.*%s\\)\""
                   ;; Hack for tex files, where \include often excludes .tex.
@@ -294,18 +363,18 @@ instead of reading master file from disk."
                            inc-name (- (length inc-name)
                                        (length source-file-nondir)) nil))
                 (flymake-log 3 "inc-name=%s" inc-name)
-                (when (flymake-check-include source-file-name inc-name
-                                             include-dirs)
+                (when (flymake-proc--check-include source-file-name inc-name
+                                                   include-dirs)
                   (setq found t)
                   ;;  replace-match is not used here as it fails in
                   ;; XEmacs with 'last match not a buffer' error as
                   ;; check-includes calls replace-in-string
-                  (flymake-replace-region
+                  (flymake-proc--replace-region
                    match-beg match-end
                    (file-name-nondirectory patched-source-file-name))))
               (forward-line 1)))
           (when found
-            (flymake-save-buffer-in-file patched-master-file-name)))
+            (flymake-proc--save-buffer-in-file patched-master-file-name)))
       ;;+(flymake-log 3 "killing buffer %s"
       ;;                (buffer-name master-file-temp-buffer))
       (kill-buffer master-file-temp-buffer))
@@ -315,7 +384,7 @@ instead of reading master file from disk."
     found))
 
 ;;; XXX: remove
-(defun flymake-replace-region (beg end rep)
+(defun flymake-proc--replace-region (beg end rep)
   "Replace text in BUFFER in region (BEG END) with REP."
   (save-excursion
     (goto-char end)
@@ -323,14 +392,14 @@ instead of reading master file from disk."
     (insert rep)
     (delete-region beg end)))
 
-(defun flymake-read-file-to-temp-buffer (file-name)
+(defun flymake-proc--read-file-to-temp-buffer (file-name)
   "Insert contents of FILE-NAME into newly created temp buffer."
   (let* ((temp-buffer (get-buffer-create (generate-new-buffer-name (concat "flymake:" (file-name-nondirectory file-name))))))
     (with-current-buffer temp-buffer
       (insert-file-contents file-name))
     temp-buffer))
 
-(defun flymake-copy-buffer-to-temp-buffer (buffer)
+(defun flymake-proc--copy-buffer-to-temp-buffer (buffer)
   "Copy contents of BUFFER into newly created temp buffer."
   (with-current-buffer
       (get-buffer-create (generate-new-buffer-name
@@ -338,13 +407,13 @@ instead of reading master file from disk."
     (insert-buffer-substring buffer)
     (current-buffer)))
 
-(defun flymake-check-include (source-file-name inc-name include-dirs)
+(defun flymake-proc--check-include (source-file-name inc-name include-dirs)
   "Check if SOURCE-FILE-NAME can be found in include path.
 Return t if it can be found via include path using INC-NAME."
   (if (file-name-absolute-p inc-name)
-      (flymake-same-files source-file-name inc-name)
+      (flymake-proc--same-files source-file-name inc-name)
     (while (and include-dirs
-                (not (flymake-same-files
+                (not (flymake-proc--same-files
                       source-file-name
                       (concat (file-name-directory source-file-name)
                               "/" (car include-dirs)
@@ -352,17 +421,17 @@ Return t if it can be found via include path using INC-NAME."
       (setq include-dirs (cdr include-dirs)))
     include-dirs))
 
-(defun flymake-find-buffer-for-file (file-name)
+(defun flymake-proc--find-buffer-for-file (file-name)
   "Check if there exists a buffer visiting FILE-NAME.
 Return t if so, nil if not."
   (let ((buffer-name (get-file-buffer file-name)))
     (if buffer-name
 	(get-buffer buffer-name))))
 
-(defun flymake-create-master-file (source-file-name patched-source-file-name get-incl-dirs-f create-temp-f masks include-regexp)
+(defun flymake-proc--create-master-file (source-file-name patched-source-file-name get-incl-dirs-f create-temp-f masks include-regexp)
   "Save SOURCE-FILE-NAME with a different name.
 Find master file, patch and save it."
-  (let* ((possible-master-files     (flymake-find-possible-master-files source-file-name flymake-master-file-dirs masks))
+  (let* ((possible-master-files     (flymake-proc--find-possible-master-files source-file-name flymake-proc-master-file-dirs masks))
 	 (master-file-count         (length possible-master-files))
 	 (idx                       0)
 	 (temp-buffer               nil)
@@ -373,11 +442,11 @@ Find master file, patch and save it."
     (while (and (not found) (< idx master-file-count))
       (setq master-file-name (nth idx possible-master-files))
       (setq patched-master-file-name (funcall create-temp-f master-file-name "flymake_master"))
-      (if (flymake-find-buffer-for-file master-file-name)
-	  (setq temp-buffer (flymake-copy-buffer-to-temp-buffer (flymake-find-buffer-for-file master-file-name)))
-	(setq temp-buffer (flymake-read-file-to-temp-buffer master-file-name)))
+      (if (flymake-proc--find-buffer-for-file master-file-name)
+	  (setq temp-buffer (flymake-proc--copy-buffer-to-temp-buffer (flymake-proc--find-buffer-for-file master-file-name)))
+	(setq temp-buffer (flymake-proc--read-file-to-temp-buffer master-file-name)))
       (setq found
-	    (flymake-check-patch-master-file-buffer
+	    (flymake-proc--check-patch-master-file-buffer
 	     temp-buffer
 	     master-file-name
 	     patched-master-file-name
@@ -393,260 +462,185 @@ Find master file, patch and save it."
 		     (file-name-nondirectory source-file-name))
 	nil))))
 
-(defun flymake-save-buffer-in-file (file-name)
+(defun flymake-proc--save-buffer-in-file (file-name)
   "Save the entire buffer contents into file FILE-NAME.
 Create parent directories as needed."
   (make-directory (file-name-directory file-name) 1)
   (write-region nil nil file-name nil 566)
   (flymake-log 3 "saved buffer %s in file %s" (buffer-name) file-name))
 
-(defun flymake-process-filter (process output)
-  "Parse OUTPUT and highlight error lines.
-It's flymake process filter."
-  (let ((source-buffer (process-buffer process)))
-
-    (flymake-log 3 "received %d byte(s) of output from process %d"
-                 (length output) (process-id process))
-    (when (buffer-live-p source-buffer)
-      (with-current-buffer source-buffer
-        (flymake-parse-output-and-residual output)))))
-
-(defun flymake-process-sentinel (process _event)
+(defun flymake-proc--diagnostics-for-pattern (proc pattern)
+  (cl-flet ((guess-type
+             (pred message)
+             (cond ((null message)
+                    :error)
+                   ((stringp pred)
+                    (if (string-match pred message)
+                        :warning
+                      :error))
+                   ((functionp pred)
+                    (let ((probe (funcall pred message)))
+                      (cond ((assoc-default probe
+                                            flymake-diagnostic-types-alist)
+                             probe)
+                            (probe
+                             :warning)
+                            (t
+                             :error)))))))
+    (condition-case-unless-debug err
+        (cl-loop
+         with (regexp file-idx line-idx col-idx message-idx) = pattern
+         while (and
+                (search-forward-regexp regexp nil t)
+                ;; If the preceding search spanned more than one line,
+                ;; move to the start of the line we ended up in. This
+                ;; preserves the usefulness of the patterns in
+                ;; `flymake-proc-err-line-patterns', which were
+                ;; written primarily for flymake's original
+                ;; line-by-line parsing and thus never spanned
+                ;; multiple lines.
+                (if (/= (line-number-at-pos (match-beginning 0))
+                        (line-number-at-pos))
+                    (goto-char (line-beginning-position))
+                  t))
+         for fname = (and file-idx (match-string file-idx))
+         for message = (and message-idx (match-string message-idx))
+         for line-string = (and line-idx (match-string line-idx))
+         for line-number = (or (and line-string
+                                    (string-to-number line-string))
+                               1)
+         for col-string = (and col-idx (match-string col-idx))
+         for col-number = (and col-string
+                               (string-to-number col-string))
+         for full-file = (with-current-buffer (process-buffer proc)
+                           (and fname
+                                (funcall
+                                 (flymake-proc--get-real-file-name-function
+                                  fname)
+                                 fname)))
+         for buffer = (and full-file
+                           (find-buffer-visiting full-file))
+         if (and (eq buffer (process-buffer proc)) message)
+         collect (pcase-let ((`(,beg . ,end)
+                              (flymake-diag-region buffer line-number col-number)))
+                   (flymake-make-diagnostic
+                    buffer beg end
+                    (with-current-buffer buffer
+                      (guess-type flymake-proc-diagnostic-type-pred message))
+                    message))
+         else
+         do (flymake-log 2 "Reference to file %s is out of scope" fname))
+      (error
+       (flymake-log 1 "Error parsing process output for pattern %s: %s"
+                    pattern err)
+       nil))))
+
+(defun flymake-proc--process-filter (proc string)
+  "Parse STRING and collect diagnostics info."
+  (flymake-log 3 "received %d byte(s) of output from process %d"
+               (length string) (process-id proc))
+  (let ((output-buffer (process-get proc 'flymake-proc--output-buffer)))
+    (when (and (buffer-live-p (process-buffer proc))
+               output-buffer)
+      (with-current-buffer output-buffer
+        (let ((moving (= (point) (process-mark proc)))
+              (inhibit-read-only t)
+              (unprocessed-mark
+               (or (process-get proc 'flymake-proc--unprocessed-mark)
+                   (set-marker (make-marker) (point-min)))))
+          (save-excursion
+            ;; Insert the text, advancing the process marker.
+            (goto-char (process-mark proc))
+            (insert string)
+            (set-marker (process-mark proc) (point)))
+          (if moving (goto-char (process-mark proc)))
+
+          ;; check for new diagnostics
+          ;;
+          (save-excursion
+            (goto-char unprocessed-mark)
+            (dolist (pattern flymake-proc-err-line-patterns)
+              (let ((new (flymake-proc--diagnostics-for-pattern proc pattern)))
+                (process-put
+                 proc
+                 'flymake-proc--collected-diagnostics
+                 (append new
+                         (process-get proc
+                                      'flymake-proc--collected-diagnostics)))))
+            (process-put proc 'flymake-proc--unprocessed-mark
+                         (point-marker))))))))
+
+(defun flymake-proc--process-sentinel (proc _event)
   "Sentinel for syntax check buffers."
-  (when (memq (process-status process) '(signal exit))
-    (let* ((exit-status       (process-exit-status process))
-           (command           (process-command process))
-           (source-buffer     (process-buffer process))
-           (cleanup-f         (flymake-get-cleanup-function (buffer-file-name source-buffer))))
-
-      (flymake-log 2 "process %d exited with code %d"
-                   (process-id process) exit-status)
-      (condition-case err
-          (progn
-            (flymake-log 3 "cleaning up using %s" cleanup-f)
-            (when (buffer-live-p source-buffer)
-              (with-current-buffer source-buffer
-                (funcall cleanup-f)))
-
-            (delete-process process)
-            (setq flymake-processes (delq process flymake-processes))
-
-            (when (buffer-live-p source-buffer)
-              (with-current-buffer source-buffer
-
-                (flymake-parse-residual)
-                (flymake-post-syntax-check exit-status command)
-                (setq flymake-is-running nil))))
-        (error
-         (let ((err-str (format "Error in process sentinel for buffer %s: %s"
-                                source-buffer (error-message-string err))))
-           (flymake-log 0 err-str)
-           (with-current-buffer source-buffer
-             (setq flymake-is-running nil))))))))
-
-(defun flymake-post-syntax-check (exit-status command)
-  (save-restriction
-    (widen)
-    (setq flymake-err-info flymake-new-err-info)
-    (setq flymake-new-err-info nil)
-    (setq flymake-err-info
-          (flymake-fix-line-numbers
-           flymake-err-info 1 (count-lines (point-min) (point-max))))
-    (flymake-delete-own-overlays)
-    (flymake-highlight-err-lines flymake-err-info)
-    (let (err-count warn-count)
-      (setq err-count (flymake-get-err-count flymake-err-info "e"))
-      (setq warn-count  (flymake-get-err-count flymake-err-info "w"))
-      (flymake-log 2 "%s: %d error(s), %d warning(s) in %.2f second(s)"
-                   (buffer-name) err-count warn-count
-                   (- (float-time) flymake-check-start-time))
-      (setq flymake-check-start-time nil)
-
-      (if (and (equal 0 err-count) (equal 0 warn-count))
-          (if (equal 0 exit-status)
-              (flymake-report-status "" "") ; PASSED
-            (if (not flymake-check-was-interrupted)
-                (flymake-report-fatal-status "CFGERR"
-                                             (format "Configuration error has occurred while running %s" command))
-              (flymake-report-status nil ""))) ; "STOPPED"
-        (flymake-report-status (format "%d/%d" err-count warn-count) "")))))
-
-(defun flymake-parse-output-and-residual (output)
-  "Split OUTPUT into lines, merge in residual if necessary."
-  (let* ((buffer-residual     flymake-output-residual)
-         (total-output        (if buffer-residual (concat buffer-residual output) output))
-         (lines-and-residual  (flymake-split-output total-output))
-         (lines               (nth 0 lines-and-residual))
-         (new-residual        (nth 1 lines-and-residual)))
-    (setq flymake-output-residual new-residual)
-    (setq flymake-new-err-info
-          (flymake-parse-err-lines
-           flymake-new-err-info lines))))
-
-(defun flymake-parse-residual ()
-  "Parse residual if it's non empty."
-  (when flymake-output-residual
-    (setq flymake-new-err-info
-          (flymake-parse-err-lines
-           flymake-new-err-info
-           (list flymake-output-residual)))
-    (setq flymake-output-residual nil)))
-
-(defun flymake-fix-line-numbers (err-info-list min-line max-line)
-  "Replace line numbers with fixed value.
-If line-numbers is less than MIN-LINE, set line numbers to MIN-LINE.
-If line numbers is greater than MAX-LINE, set line numbers to MAX-LINE.
-The reason for this fix is because some compilers might report
-line number outside the file being compiled."
-  (let* ((count     (length err-info-list))
-	 (err-info  nil)
-	 (line      0))
-    (while (> count 0)
-      (setq err-info (nth (1- count) err-info-list))
-      (setq line (flymake-er-get-line err-info))
-      (when (or (< line min-line) (> line max-line))
-	(setq line (if (< line min-line) min-line max-line))
-	(setq err-info-list (flymake-set-at err-info-list (1- count)
-					    (flymake-er-make-er line
-								(flymake-er-get-line-err-info-list err-info)))))
-      (setq count (1- count))))
-  err-info-list)
-
-(defun flymake-parse-err-lines (err-info-list lines)
-  "Parse err LINES, store info in ERR-INFO-LIST."
-  (let* ((count              (length lines))
-	 (idx                0)
-	 (line-err-info      nil)
-	 (real-file-name     nil)
-	 (source-file-name   buffer-file-name)
-	 (get-real-file-name-f (flymake-get-real-file-name-function source-file-name)))
-
-    (while (< idx count)
-      (setq line-err-info (flymake-parse-line (nth idx lines)))
-      (when line-err-info
-	(setq real-file-name (funcall get-real-file-name-f
-                                      (flymake-ler-file line-err-info)))
-	(setq line-err-info (flymake-ler-set-full-file line-err-info real-file-name))
-
-	(when (flymake-same-files real-file-name source-file-name)
-	  (setq line-err-info (flymake-ler-set-file line-err-info nil))
-	  (setq err-info-list (flymake-add-err-info err-info-list line-err-info))))
-      (flymake-log 3 "parsed `%s', %s line-err-info" (nth idx lines) (if line-err-info "got" "no"))
-      (setq idx (1+ idx)))
-    err-info-list))
-
-(defun flymake-split-output (output)
-  "Split OUTPUT into lines.
-Return last one as residual if it does not end with newline char.
-Returns ((LINES) RESIDUAL)."
-  (when (and output (> (length output) 0))
-    (let* ((lines (split-string output "[\n\r]+" t))
-	   (complete (equal "\n" (char-to-string (aref output (1- (length output))))))
-	   (residual nil))
-      (when (not complete)
-	(setq residual (car (last lines)))
-	(setq lines (butlast lines)))
-      (list lines residual))))
-
-(defun flymake-reformat-err-line-patterns-from-compile-el (original-list)
-  "Grab error line patterns from ORIGINAL-LIST in compile.el format.
-Convert it to flymake internal format."
-  (let* ((converted-list '()))
-    (dolist (item original-list)
-      (setq item (cdr item))
-      (let ((regexp (nth 0 item))
-	    (file (nth 1 item))
-	    (line (nth 2 item))
-	    (col (nth 3 item)))
-	(if (consp file)	(setq file (car file)))
-	(if (consp line)	(setq line (car line)))
-	(if (consp col)	(setq col (car col)))
-
-	(when (not (functionp line))
-	  (setq converted-list (cons (list regexp file line col) converted-list)))))
-    converted-list))
+  (let (debug
+        (pid (process-id proc))
+        (source-buffer (process-buffer proc)))
+    (unwind-protect
+        (when (buffer-live-p source-buffer)
+          (with-current-buffer source-buffer
+            (cond ((process-get proc 'flymake-proc--obsolete)
+                   (flymake-log 3 "proc %s considered obsolete"
+                                pid))
+                  ((process-get proc 'flymake-proc--interrupted)
+                   (flymake-log 3 "proc %s interrupted by user"
+                                pid))
+                  ((not (process-live-p proc))
+                   (let* ((exit-status   (process-exit-status proc))
+                          (command       (process-command proc))
+                          (diagnostics (process-get
+                                        proc
+                                        'flymake-proc--collected-diagnostics)))
+                     (flymake-log 2 "process %d exited with code %d"
+                                  pid exit-status)
+                     (cond
+                      ((equal 0 exit-status)
+                       (funcall flymake-proc--report-fn diagnostics
+                                :explanation (format "a gift from %s" (process-id proc))
+                                ))
+                      (diagnostics
+                       ;; non-zero exit but some diagnostics is quite
+                       ;; normal...
+                       (funcall flymake-proc--report-fn diagnostics
+                                :explanation (format "a gift from %s" (process-id proc))))
+                      ((null diagnostics)
+                       ;; ...but no diagnostics is strange, so panic.
+                       (setq debug debug-on-error)
+                       (flymake-proc--panic
+                        :configuration-error
+                        (format "Command %s errored, but no diagnostics"
+                                command)))))))))
+      (let ((output-buffer (process-get proc 'flymake-proc--output-buffer)))
+        (cond (debug
+               (flymake-log 3 "Output buffer %s kept alive for debugging"
+                            output-buffer))
+              (t
+               (when (buffer-live-p source-buffer)
+                 (with-current-buffer source-buffer
+                   (let ((cleanup-f (flymake-proc--get-cleanup-function
+                                     (buffer-file-name))))
+                     (flymake-log 3 "cleaning up using %s" cleanup-f)
+                     (funcall cleanup-f))))
+               (kill-buffer output-buffer)))))))
+
+(defun flymake-proc--panic (problem explanation)
+  "Tell Flymake UI about a fatal PROBLEM with this backend.
+May only be called in a dynamic environment where
+`flymake-proc--report-fn' is bound."
+  (flymake-log 0 "%s: %s" problem explanation)
+  (if (and (boundp 'flymake-proc--report-fn)
+           flymake-proc--report-fn)
+      (funcall flymake-proc--report-fn :panic
+               :explanation (format "%s: %s" problem explanation))
+    (flymake-error "Trouble telling flymake-ui about problem %s(%s)"
+                   problem explanation)))
 
 (require 'compile)
 
-(defvar flymake-err-line-patterns ; regexp file-idx line-idx col-idx (optional) text-idx(optional), match-end to end of string is error text
-  (append
-   '(
-     ;; MS Visual C++ 6.0
-     ("\\(\\([a-zA-Z]:\\)?[^:(\t\n]+\\)(\\([0-9]+\\)) : \\(\\(error\\|warning\\|fatal error\\) \\(C[0-9]+\\):[ \t\n]*\\(.+\\)\\)"
-      1 3 nil 4)
-     ;; jikes
-     ("\\(\\([a-zA-Z]:\\)?[^:(\t\n]+\\):\\([0-9]+\\):[0-9]+:[0-9]+:[0-9]+: \\(\\(Error\\|Warning\\|Caution\\|Semantic Error\\):[ \t\n]*\\(.+\\)\\)"
-      1 3 nil 4)
-     ;; MS midl
-     ("midl[ ]*:[ ]*\\(command line error .*\\)"
-      nil nil nil 1)
-     ;; MS C#
-     ("\\(\\([a-zA-Z]:\\)?[^:(\t\n]+\\)(\\([0-9]+\\),[0-9]+): \\(\\(error\\|warning\\|fatal error\\) \\(CS[0-9]+\\):[ \t\n]*\\(.+\\)\\)"
-      1 3 nil 4)
-     ;; perl
-     ("\\(.*\\) at \\([^ \n]+\\) line \\([0-9]+\\)[,.\n]" 2 3 nil 1)
-     ;; PHP
-     ("\\(?:Parse\\|Fatal\\) error: \\(.*\\) in \\(.*\\) on line \\([0-9]+\\)" 2 3 nil 1)
-     ;; LaTeX warnings (fileless) ("\\(LaTeX \\(Warning\\|Error\\): .*\\) on input line \\([0-9]+\\)" 20 3 nil 1)
-     ;; ant/javac.  Note this also matches gcc warnings!
-     (" *\\(\\[javac\\] *\\)?\\(\\([a-zA-Z]:\\)?[^:(\t\n]+\\):\\([0-9]+\\)\\(?::[0-9]+\\)?:[ \t\n]*\\(.+\\)"
-      2 4 nil 5))
-   ;; compilation-error-regexp-alist)
-   (flymake-reformat-err-line-patterns-from-compile-el compilation-error-regexp-alist-alist))
-  "Patterns for matching error/warning lines.  Each pattern has the form
-\(REGEXP FILE-IDX LINE-IDX COL-IDX ERR-TEXT-IDX).
-Use `flymake-reformat-err-line-patterns-from-compile-el' to add patterns
-from compile.el")
-
-(define-obsolete-variable-alias 'flymake-warning-re 'flymake-warning-predicate "24.4")
-(defvar flymake-warning-predicate "^[wW]arning"
-  "Predicate matching against error text to detect a warning.
-Takes a single argument, the error's text and should return non-nil
-if it's a warning.
-Instead of a function, it can also be a regular expression.")
-
-(defun flymake-parse-line (line)
-  "Parse LINE to see if it is an error or warning.
-Return its components if so, nil otherwise."
-  (let ((raw-file-name nil)
-	(line-no 0)
-	(err-type "e")
-	(err-text nil)
-	(patterns flymake-err-line-patterns)
-	(matched nil))
-    (while (and patterns (not matched))
-      (when (string-match (car (car patterns)) line)
-	(let* ((file-idx (nth 1 (car patterns)))
-	       (line-idx (nth 2 (car patterns))))
-
-	  (setq raw-file-name (if file-idx (match-string file-idx line) nil))
-	  (setq line-no       (if line-idx (string-to-number
-                                            (match-string line-idx line)) 0))
-	  (setq err-text      (if (> (length (car patterns)) 4)
-				  (match-string (nth 4 (car patterns)) line)
-				(flymake-patch-err-text
-                                 (substring line (match-end 0)))))
-	  (if (null err-text)
-              (setq err-text "<no error text>")
-            (when (cond ((stringp flymake-warning-predicate)
-                         (string-match flymake-warning-predicate err-text))
-                        ((functionp flymake-warning-predicate)
-                         (funcall flymake-warning-predicate err-text)))
-              (setq err-type "w")))
-	  (flymake-log
-           3 "parse line: file-idx=%s line-idx=%s file=%s line=%s text=%s"
-           file-idx line-idx raw-file-name line-no err-text)
-	  (setq matched t)))
-      (setq patterns (cdr patterns)))
-    (if matched
-	(flymake-ler-make-ler raw-file-name line-no err-type err-text)
-      ())))
-
-(defun flymake-get-project-include-dirs-imp (basedir)
+(defun flymake-proc-get-project-include-dirs-imp (basedir)
   "Include dirs for the project current file belongs to."
-  (if (flymake-get-project-include-dirs-from-cache basedir)
+  (if (flymake-proc--get-project-include-dirs-from-cache basedir)
       (progn
-	(flymake-get-project-include-dirs-from-cache basedir))
+	(flymake-proc--get-project-include-dirs-from-cache basedir))
     ;;else
     (let* ((command-line  (concat "make -C "
 				  (shell-quote-argument basedir)
@@ -665,148 +659,170 @@ Return its components if so, nil otherwise."
 	    (when (not (string-match "^INCLUDE_DIRS=.*" (nth (1- inc-count) inc-lines)))
 	      (push (replace-regexp-in-string "\"" "" (nth (1- inc-count) inc-lines)) inc-dirs))
 	    (setq inc-count (1- inc-count)))))
-      (flymake-add-project-include-dirs-to-cache basedir inc-dirs)
+      (flymake-proc--add-project-include-dirs-to-cache basedir inc-dirs)
       inc-dirs)))
 
-(defvar flymake-get-project-include-dirs-function #'flymake-get-project-include-dirs-imp
+(defvar flymake-proc-get-project-include-dirs-function #'flymake-proc-get-project-include-dirs-imp
   "Function used to get project include dirs, one parameter: basedir name.")
 
-(defun flymake-get-project-include-dirs (basedir)
-  (funcall flymake-get-project-include-dirs-function basedir))
+(defun flymake-proc--get-project-include-dirs (basedir)
+  (funcall flymake-proc-get-project-include-dirs-function basedir))
 
-(defun flymake-get-system-include-dirs ()
+(defun flymake-proc--get-system-include-dirs ()
   "System include dirs - from the `INCLUDE' env setting."
   (let* ((includes (getenv "INCLUDE")))
     (if includes (split-string includes path-separator t) nil)))
 
-(defvar flymake-project-include-dirs-cache (make-hash-table :test #'equal))
+(defvar flymake-proc--project-include-dirs-cache (make-hash-table :test #'equal))
 
-(defun flymake-get-project-include-dirs-from-cache (base-dir)
-  (gethash base-dir flymake-project-include-dirs-cache))
+(defun flymake-proc--get-project-include-dirs-from-cache (base-dir)
+  (gethash base-dir flymake-proc--project-include-dirs-cache))
 
-(defun flymake-add-project-include-dirs-to-cache (base-dir include-dirs)
-  (puthash base-dir include-dirs flymake-project-include-dirs-cache))
+(defun flymake-proc--add-project-include-dirs-to-cache (base-dir include-dirs)
+  (puthash base-dir include-dirs flymake-proc--project-include-dirs-cache))
 
-(defun flymake-clear-project-include-dirs-cache ()
-  (clrhash flymake-project-include-dirs-cache))
+(defun flymake-proc--clear-project-include-dirs-cache ()
+  (clrhash flymake-proc--project-include-dirs-cache))
 
-(defun flymake-get-include-dirs (base-dir)
+(defun flymake-proc-get-include-dirs (base-dir)
   "Get dirs to use when resolving local file names."
-  (let* ((include-dirs (append '(".") (flymake-get-project-include-dirs base-dir) (flymake-get-system-include-dirs))))
+  (let* ((include-dirs (append '(".") (flymake-proc--get-project-include-dirs base-dir) (flymake-proc--get-system-include-dirs))))
     include-dirs))
 
-;; (defun flymake-restore-formatting ()
+;; (defun flymake-proc--restore-formatting ()
 ;;   "Remove any formatting made by flymake."
 ;;   )
 
-;; (defun flymake-get-program-dir (buffer)
+;; (defun flymake-proc--get-program-dir (buffer)
 ;;   "Get dir to start program in."
 ;;   (unless (bufferp buffer)
 ;;     (error "Invalid buffer"))
 ;;   (with-current-buffer buffer
 ;;     default-directory))
 
-(defun flymake-safe-delete-file (file-name)
+(defun flymake-proc--safe-delete-file (file-name)
   (when (and file-name (file-exists-p file-name))
     (delete-file file-name)
-    (flymake-log 1 "deleted file %s" file-name)))
+    (flymake-log 2 "deleted file %s" file-name)))
 
-(defun flymake-safe-delete-directory (dir-name)
-  (condition-case nil
+(defun flymake-proc--safe-delete-directory (dir-name)
+  (condition-case-unless-debug nil
       (progn
 	(delete-directory dir-name)
-	(flymake-log 1 "deleted dir %s" dir-name))
+	(flymake-log 2 "deleted dir %s" dir-name))
     (error
      (flymake-log 1 "Failed to delete dir %s, error ignored" dir-name))))
 
-(defun flymake-proc-start-syntax-check ()
-  "Start syntax checking for current buffer."
-  (interactive)
-  (flymake-log 3 "flymake is running: %s" flymake-is-running)
-  (when (not flymake-is-running)
-    (when (or (not flymake-compilation-prevents-syntax-check)
-              (not (flymake-compilation-is-running))) ;+ (flymake-rep-ort-status buffer "COMP")
-      (flymake-clear-buildfile-cache)
-      (flymake-clear-project-include-dirs-cache)
-
-      (setq flymake-check-was-interrupted nil)
-
-      (let* ((source-file-name  buffer-file-name)
-             (init-f (flymake-get-init-function source-file-name))
-             (cleanup-f (flymake-get-cleanup-function source-file-name))
-             (cmd-and-args (funcall init-f))
-             (cmd          (nth 0 cmd-and-args))
-             (args         (nth 1 cmd-and-args))
-             (dir          (nth 2 cmd-and-args)))
-        (if (not cmd-and-args)
-            (progn
-              (flymake-log 0 "init function %s for %s failed, cleaning up" init-f source-file-name)
-              (funcall cleanup-f))
-          (progn
-            (setq flymake-last-change-time nil)
-            (flymake-start-syntax-check-process cmd args dir)))))))
-
-(defun flymake-start-syntax-check-process (cmd args dir)
-  "Start syntax check process."
-  (condition-case err
-      (let* ((process
-              (let ((default-directory (or dir default-directory)))
-                (when dir
-                  (flymake-log 3 "starting process on dir %s" dir))
-                (apply 'start-file-process
-                       "flymake-proc" (current-buffer) cmd args))))
-        (set-process-sentinel process 'flymake-process-sentinel)
-        (set-process-filter process 'flymake-process-filter)
-        (set-process-query-on-exit-flag process nil)
-        (push process flymake-processes)
-
-        (setq flymake-is-running t)
-        (setq flymake-last-change-time nil)
-        (setq flymake-check-start-time (float-time))
-
-        (flymake-report-status nil "*")
-        (flymake-log 2 "started process %d, command=%s, dir=%s"
-                     (process-id process) (process-command process)
-                     default-directory)
-        process)
-    (error
-     (let* ((err-str
-             (format-message
-              "Failed to launch syntax check process `%s' with args %s: %s"
-              cmd args (error-message-string err)))
-            (source-file-name buffer-file-name)
-            (cleanup-f        (flymake-get-cleanup-function source-file-name)))
-       (flymake-log 0 err-str)
-       (funcall cleanup-f)
-       (flymake-report-fatal-status "PROCERR" err-str)))))
-
-(defun flymake-kill-process (proc)
-  "Kill process PROC."
-  (kill-process proc)
-  (let* ((buf (process-buffer proc)))
-    (when (buffer-live-p buf)
-      (with-current-buffer buf
-	(setq flymake-check-was-interrupted t))))
-  (flymake-log 1 "killed process %d" (process-id proc)))
-
-(defun flymake-stop-all-syntax-checks ()
-  "Kill all syntax check processes."
-  (interactive)
-  (while flymake-processes
-    (flymake-kill-process (pop flymake-processes))))
 
-(defun flymake-compilation-is-running ()
+(defun flymake-proc-legacy-flymake (report-fn &rest args)
+  "Flymake backend based on the original Flymake implementation.
+This function is suitable for inclusion in
+`flymake-diagnostic-functions'. For backward compatibility, it
+can also be executed interactively independently of
+`flymake-mode'."
+  ;; Interactively, behave as if flymake had invoked us through its
+  ;; `flymake-diagnostic-functions' with a suitable ID so flymake can
+  ;; clean up consistently
+  (interactive (list
+                (lambda (diags &rest args)
+                  (apply (flymake-make-report-fn 'flymake-proc-legacy-flymake)
+                         diags
+                         (append args '(:force t))))
+                :interactive t))
+  (let ((interactive (plist-get args :interactive))
+        (proc flymake-proc--current-process)
+        (flymake-proc--report-fn report-fn))
+    (when (processp proc)
+      (process-put proc 'flymake-proc--obsolete t)
+      (flymake-log 3 "marking %s obsolete" (process-id proc))
+      (when (process-live-p proc)
+        (when interactive
+          (user-error
+           "There's already a Flymake process running in this buffer")
+          (kill-process proc))))
+    (when
+        ;; This particular situation make us not want to error right
+        ;; away (and disable ourselves), in case the situation changes
+        ;; in the near future.
+        (and (or (not flymake-proc-compilation-prevents-syntax-check)
+                 (not (flymake-proc--compilation-is-running))))
+      (let ((init-f
+             (and
+              buffer-file-name
+              ;; Since we write temp files in current dir, there's no point
+              ;; trying if the directory is read-only (bug#8954).
+              (file-writable-p (file-name-directory buffer-file-name))
+              (flymake-proc--get-init-function buffer-file-name))))
+        (unless init-f (error "Can find a suitable init function"))
+        (flymake-proc--clear-buildfile-cache)
+        (flymake-proc--clear-project-include-dirs-cache)
+
+        (let* ((cleanup-f (flymake-proc--get-cleanup-function buffer-file-name))
+               (cmd-and-args (funcall init-f))
+               (cmd          (nth 0 cmd-and-args))
+               (args         (nth 1 cmd-and-args))
+               (dir          (nth 2 cmd-and-args))
+               (success nil))
+          (unwind-protect
+              (cond
+               ((not cmd-and-args)
+                (flymake-log 0 "init function %s for %s failed, cleaning up"
+                             init-f buffer-file-name))
+               (t
+                (setq proc
+                      (let ((default-directory (or dir default-directory)))
+                        (when dir
+                          (flymake-log 3 "starting process on dir %s" dir))
+                        (make-process
+                         :name "flymake-proc"
+                         :buffer (current-buffer)
+                         :command (cons cmd args)
+                         :noquery t
+                         :filter
+                         (lambda (proc string)
+                           (let ((flymake-proc--report-fn report-fn))
+                             (flymake-proc--process-filter proc string)))
+                         :sentinel
+                         (lambda (proc event)
+                           (let ((flymake-proc--report-fn report-fn))
+                             (flymake-proc--process-sentinel proc event))))))
+                (process-put proc 'flymake-proc--output-buffer
+                             (generate-new-buffer
+                              (format " *flymake output for %s*" (current-buffer))))
+                (setq flymake-proc--current-process proc)
+                (flymake-log 2 "started process %d, command=%s, dir=%s"
+                             (process-id proc) (process-command proc)
+                             default-directory)
+                (setq success t)))
+            (unless success
+              (funcall cleanup-f))))))))
+
+(define-obsolete-function-alias 'flymake-start-syntax-check
+  'flymake-proc-legacy-flymake "26.1")
+
+(defun flymake-proc-stop-all-syntax-checks (&optional reason)
+  "Kill all syntax check processes."
+  (interactive (list "Interrupted by user"))
+  (dolist (buf (buffer-list))
+    (with-current-buffer buf
+      (let (p flymake-proc--current-process)
+        (when (process-live-p p)
+          (kill-process p)
+          (process-put p 'flymake-proc--interrupted reason)
+          (flymake-log 2 "killed process %d" (process-id p)))))))
+
+(defun flymake-proc--compilation-is-running ()
   (and (boundp 'compilation-in-progress)
        compilation-in-progress))
 
-(defun flymake-compile ()
-  "Kill all flymake syntax checks, start compilation."
+(defun flymake-proc-compile ()
+  "Kill all Flymake syntax checks, start compilation."
   (interactive)
-  (flymake-stop-all-syntax-checks)
+  (flymake-proc-stop-all-syntax-checks "Stopping for proper compilation")
   (call-interactively 'compile))
 
 ;;;; general init-cleanup and helper routines
-(defun flymake-create-temp-inplace (file-name prefix)
+(defun flymake-proc-create-temp-inplace (file-name prefix)
   (unless (stringp file-name)
     (error "Invalid file-name"))
   (or prefix
@@ -819,7 +835,7 @@ Return its components if so, nil otherwise."
     (flymake-log 3 "create-temp-inplace: file=%s temp=%s" file-name temp-name)
     temp-name))
 
-(defun flymake-create-temp-with-folder-structure (file-name _prefix)
+(defun flymake-proc-create-temp-with-folder-structure (file-name _prefix)
   (unless (stringp file-name)
     (error "Invalid file-name"))
 
@@ -833,48 +849,47 @@ Return its components if so, nil otherwise."
     (file-truename (expand-file-name (file-name-nondirectory file-name)
                                      temp-dir))))
 
-(defun flymake-delete-temp-directory (dir-name)
-  "Attempt to delete temp dir created by `flymake-create-temp-with-folder-structure', do not fail on error."
+(defun flymake-proc--delete-temp-directory (dir-name)
+  "Attempt to delete temp dir created by `flymake-proc-create-temp-with-folder-structure', do not fail on error."
   (let* ((temp-dir    temporary-file-directory)
 	 (suffix      (substring dir-name (1+ (length temp-dir)))))
 
     (while (> (length suffix) 0)
       (setq suffix (directory-file-name suffix))
       ;;+(flymake-log 0 "suffix=%s" suffix)
-      (flymake-safe-delete-directory
+      (flymake-proc--safe-delete-directory
        (file-truename (expand-file-name suffix temp-dir)))
       (setq suffix (file-name-directory suffix)))))
 
-(defvar-local flymake-temp-source-file-name nil)
-(defvar-local flymake-master-file-name nil)
-(defvar-local flymake-temp-master-file-name nil)
-(defvar-local flymake-base-dir nil)
+(defvar-local flymake-proc--temp-source-file-name nil)
+(defvar-local flymake-proc--master-file-name nil)
+(defvar-local flymake-proc--temp-master-file-name nil)
+(defvar-local flymake-proc--base-dir nil)
 
-(defun flymake-init-create-temp-buffer-copy (create-temp-f)
+(defun flymake-proc-init-create-temp-buffer-copy (create-temp-f)
   "Make a temporary copy of the current buffer, save its name in buffer data and return the name."
   (let*  ((source-file-name       buffer-file-name)
 	  (temp-source-file-name  (funcall create-temp-f source-file-name "flymake")))
 
-    (flymake-save-buffer-in-file temp-source-file-name)
-    (setq flymake-temp-source-file-name temp-source-file-name)
+    (flymake-proc--save-buffer-in-file temp-source-file-name)
+    (setq flymake-proc--temp-source-file-name temp-source-file-name)
     temp-source-file-name))
 
-(defun flymake-simple-cleanup ()
-  "Do cleanup after `flymake-init-create-temp-buffer-copy'.
+(defun flymake-proc-simple-cleanup ()
+  "Do cleanup after `flymake-proc-init-create-temp-buffer-copy'.
 Delete temp file."
-  (flymake-safe-delete-file flymake-temp-source-file-name)
-  (setq flymake-last-change-time nil))
+  (flymake-proc--safe-delete-file flymake-proc--temp-source-file-name))
 
-(defun flymake-get-real-file-name (file-name-from-err-msg)
+(defun flymake-proc-get-real-file-name (file-name-from-err-msg)
   "Translate file name from error message to \"real\" file name.
 Return full-name.  Names are real, not patched."
   (let* ((real-name		nil)
 	 (source-file-name	buffer-file-name)
-	 (master-file-name	flymake-master-file-name)
-	 (temp-source-file-name	flymake-temp-source-file-name)
-	 (temp-master-file-name	flymake-temp-master-file-name)
+	 (master-file-name	flymake-proc--master-file-name)
+	 (temp-source-file-name	flymake-proc--temp-source-file-name)
+	 (temp-master-file-name	flymake-proc--temp-master-file-name)
 	 (base-dirs
-          (list flymake-base-dir
+          (list flymake-proc--base-dir
                 (file-name-directory source-file-name)
                 (if master-file-name (file-name-directory master-file-name))))
 	 (files (list (list source-file-name       source-file-name)
@@ -885,17 +900,17 @@ Return full-name.  Names are real, not patched."
     (when (equal 0 (length file-name-from-err-msg))
       (setq file-name-from-err-msg source-file-name))
 
-    (setq real-name (flymake-get-full-patched-file-name file-name-from-err-msg base-dirs files))
+    (setq real-name (flymake-proc--get-full-patched-file-name file-name-from-err-msg base-dirs files))
     ;; if real-name is nil, than file name from err msg is none of the files we've patched
     (if (not real-name)
-	(setq real-name (flymake-get-full-nonpatched-file-name file-name-from-err-msg base-dirs)))
+	(setq real-name (flymake-proc--get-full-nonpatched-file-name file-name-from-err-msg base-dirs)))
     (if (not real-name)
 	(setq real-name file-name-from-err-msg))
-    (setq real-name (flymake-fix-file-name real-name))
+    (setq real-name (flymake-proc--fix-file-name real-name))
     (flymake-log 3 "get-real-file-name: file-name=%s real-name=%s" file-name-from-err-msg real-name)
     real-name))
 
-(defun flymake-get-full-patched-file-name (file-name-from-err-msg base-dirs files)
+(defun flymake-proc--get-full-patched-file-name (file-name-from-err-msg base-dirs files)
   (let* ((base-dirs-count  (length base-dirs))
 	 (file-count       (length files))
 	 (real-name        nil))
@@ -907,7 +922,7 @@ Return full-name.  Names are real, not patched."
 	       (this-file       (nth 0 (nth (1- file-count) files)))
 	       (this-real-name  (nth 1 (nth (1- file-count) files))))
 	  ;;+(flymake-log 0 "this-dir=%s this-file=%s this-real=%s msg-file=%s" this-dir this-file this-real-name file-name-from-err-msg)
-	  (when (and this-dir this-file (flymake-same-files
+	  (when (and this-dir this-file (flymake-proc--same-files
 					 (expand-file-name file-name-from-err-msg this-dir)
 					 this-file))
 	    (setq real-name this-real-name)))
@@ -915,7 +930,7 @@ Return full-name.  Names are real, not patched."
       (setq base-dirs-count (1- base-dirs-count)))
     real-name))
 
-(defun flymake-get-full-nonpatched-file-name (file-name-from-err-msg base-dirs)
+(defun flymake-proc--get-full-nonpatched-file-name (file-name-from-err-msg base-dirs)
   (let* ((real-name  nil))
     (if (file-name-absolute-p file-name-from-err-msg)
 	(setq real-name file-name-from-err-msg)
@@ -928,41 +943,42 @@ Return full-name.  Names are real, not patched."
 	    (setq base-dirs-count (1- base-dirs-count))))))
     real-name))
 
-(defun flymake-init-find-buildfile-dir (source-file-name buildfile-name)
+(defun flymake-proc--init-find-buildfile-dir (source-file-name buildfile-name)
   "Find buildfile, store its dir in buffer data and return its dir, if found."
   (let* ((buildfile-dir
-          (flymake-find-buildfile buildfile-name
-                                  (file-name-directory source-file-name))))
+          (flymake-proc--find-buildfile buildfile-name
+                                        (file-name-directory source-file-name))))
     (if buildfile-dir
-        (setq flymake-base-dir buildfile-dir)
-      (flymake-log 1 "no buildfile (%s) for %s" buildfile-name source-file-name)
-      (flymake-report-fatal-status
+        (setq flymake-proc--base-dir buildfile-dir)
+      (flymake-proc--panic
        "NOMK" (format "No buildfile (%s) found for %s"
                       buildfile-name source-file-name)))))
 
-(defun flymake-init-create-temp-source-and-master-buffer-copy (get-incl-dirs-f create-temp-f master-file-masks include-regexp)
+(defun flymake-proc--init-create-temp-source-and-master-buffer-copy (get-incl-dirs-f create-temp-f master-file-masks include-regexp)
   "Find master file (or buffer), create its copy along with a copy of the source file."
   (let* ((source-file-name       buffer-file-name)
-	 (temp-source-file-name  (flymake-init-create-temp-buffer-copy create-temp-f))
-	 (master-and-temp-master (flymake-create-master-file
+	 (temp-source-file-name  (flymake-proc-init-create-temp-buffer-copy create-temp-f))
+	 (master-and-temp-master (flymake-proc--create-master-file
 				  source-file-name temp-source-file-name
 				  get-incl-dirs-f create-temp-f
 				  master-file-masks include-regexp)))
 
     (if (not master-and-temp-master)
 	(progn
-	  (flymake-log 1 "cannot find master file for %s" source-file-name)
-          (flymake-report-status "!" "")	; NOMASTER
+          (flymake-proc--panic
+           "NOMASTER"
+           (format-message "cannot find master file for %s"
+                           source-file-name))
           nil)
-      (setq flymake-master-file-name (nth 0 master-and-temp-master))
-      (setq flymake-temp-master-file-name (nth 1 master-and-temp-master)))))
+      (setq flymake-proc--master-file-name (nth 0 master-and-temp-master))
+      (setq flymake-proc--temp-master-file-name (nth 1 master-and-temp-master)))))
 
-(defun flymake-master-cleanup ()
-  (flymake-simple-cleanup)
-  (flymake-safe-delete-file flymake-temp-master-file-name))
+(defun flymake-proc-master-cleanup ()
+  (flymake-proc-simple-cleanup)
+  (flymake-proc--safe-delete-file flymake-proc--temp-master-file-name))
 
 ;;;; make-specific init-cleanup routines
-(defun flymake-get-syntax-check-program-args (source-file-name base-dir use-relative-base-dir use-relative-source get-cmd-line-f)
+(defun flymake-proc--get-syntax-check-program-args (source-file-name base-dir use-relative-base-dir use-relative-source get-cmd-line-f)
   "Create a command line for syntax check using GET-CMD-LINE-F."
   (funcall get-cmd-line-f
            (if use-relative-source
@@ -973,7 +989,7 @@ Return full-name.  Names are real, not patched."
                                    (file-name-directory source-file-name))
              base-dir)))
 
-(defun flymake-get-make-cmdline (source base-dir)
+(defun flymake-proc-get-make-cmdline (source base-dir)
   (list "make"
 	(list "-s"
 	      "-C"
@@ -982,119 +998,196 @@ Return full-name.  Names are real, not patched."
 	      "SYNTAX_CHECK_MODE=1"
 	      "check-syntax")))
 
-(defun flymake-get-ant-cmdline (source base-dir)
+(defun flymake-proc-get-ant-cmdline (source base-dir)
   (list "ant"
 	(list "-buildfile"
 	      (concat base-dir "/" "build.xml")
 	      (concat "-DCHK_SOURCES=" source)
 	      "check-syntax")))
 
-(defun flymake-simple-make-init-impl (create-temp-f use-relative-base-dir use-relative-source build-file-name get-cmdline-f)
+(defun flymake-proc-simple-make-init-impl (create-temp-f use-relative-base-dir use-relative-source build-file-name get-cmdline-f)
   "Create syntax check command line for a directly checked source file.
 Use CREATE-TEMP-F for creating temp copy."
   (let* ((args nil)
 	 (source-file-name   buffer-file-name)
-	 (buildfile-dir      (flymake-init-find-buildfile-dir source-file-name build-file-name)))
+	 (buildfile-dir      (flymake-proc--init-find-buildfile-dir source-file-name build-file-name)))
     (if buildfile-dir
-	(let* ((temp-source-file-name  (flymake-init-create-temp-buffer-copy create-temp-f)))
-	  (setq args (flymake-get-syntax-check-program-args temp-source-file-name buildfile-dir
-							    use-relative-base-dir use-relative-source
-							    get-cmdline-f))))
+	(let* ((temp-source-file-name  (flymake-proc-init-create-temp-buffer-copy create-temp-f)))
+	  (setq args (flymake-proc--get-syntax-check-program-args temp-source-file-name buildfile-dir
+							          use-relative-base-dir use-relative-source
+							          get-cmdline-f))))
     args))
 
-(defun flymake-simple-make-init ()
-  (flymake-simple-make-init-impl 'flymake-create-temp-inplace t t "Makefile" 'flymake-get-make-cmdline))
+(defun flymake-proc-simple-make-init ()
+  (flymake-proc-simple-make-init-impl 'flymake-proc-create-temp-inplace t t "Makefile" 'flymake-proc-get-make-cmdline))
 
-(defun flymake-master-make-init (get-incl-dirs-f master-file-masks include-regexp)
+(defun flymake-proc-master-make-init (get-incl-dirs-f master-file-masks include-regexp)
   "Create make command line for a source file checked via master file compilation."
   (let* ((make-args nil)
-	 (temp-master-file-name (flymake-init-create-temp-source-and-master-buffer-copy
-                                 get-incl-dirs-f 'flymake-create-temp-inplace
+	 (temp-master-file-name (flymake-proc--init-create-temp-source-and-master-buffer-copy
+                                 get-incl-dirs-f 'flymake-proc-create-temp-inplace
 				 master-file-masks include-regexp)))
     (when temp-master-file-name
-      (let* ((buildfile-dir (flymake-init-find-buildfile-dir temp-master-file-name "Makefile")))
+      (let* ((buildfile-dir (flymake-proc--init-find-buildfile-dir temp-master-file-name "Makefile")))
 	(if  buildfile-dir
-	    (setq make-args (flymake-get-syntax-check-program-args
-			     temp-master-file-name buildfile-dir nil nil 'flymake-get-make-cmdline)))))
+	    (setq make-args (flymake-proc--get-syntax-check-program-args
+			     temp-master-file-name buildfile-dir nil nil 'flymake-proc-get-make-cmdline)))))
     make-args))
 
-(defun flymake-find-make-buildfile (source-dir)
-  (flymake-find-buildfile "Makefile" source-dir))
+(defun flymake-proc--find-make-buildfile (source-dir)
+  (flymake-proc--find-buildfile "Makefile" source-dir))
 
 ;;;; .h/make specific
-(defun flymake-master-make-header-init ()
-  (flymake-master-make-init
-   'flymake-get-include-dirs
+(defun flymake-proc-master-make-header-init ()
+  (flymake-proc-master-make-init
+   'flymake-proc-get-include-dirs
    '("\\.\\(?:c\\(?:pp\\|xx\\|\\+\\+\\)?\\|CC\\)\\'")
    "[ \t]*#[ \t]*include[ \t]*\"\\([[:word:]0-9/\\_.]*%s\\)\""))
 
+(defun flymake-proc-real-file-name-considering-includes (scraped)
+  (flymake-proc-get-real-file-name
+   (let ((case-fold-search t))
+     (replace-regexp-in-string "^in file included from[ \t*]"
+                               ""
+                               scraped))))
+
 ;;;; .java/make specific
-(defun flymake-simple-make-java-init ()
-  (flymake-simple-make-init-impl 'flymake-create-temp-with-folder-structure nil nil "Makefile" 'flymake-get-make-cmdline))
+(defun flymake-proc-simple-make-java-init ()
+  (flymake-proc-simple-make-init-impl 'flymake-proc-create-temp-with-folder-structure nil nil "Makefile" 'flymake-proc-get-make-cmdline))
 
-(defun flymake-simple-ant-java-init ()
-  (flymake-simple-make-init-impl 'flymake-create-temp-with-folder-structure nil nil "build.xml" 'flymake-get-ant-cmdline))
+(defun flymake-proc-simple-ant-java-init ()
+  (flymake-proc-simple-make-init-impl 'flymake-proc-create-temp-with-folder-structure nil nil "build.xml" 'flymake-proc-get-ant-cmdline))
 
-(defun flymake-simple-java-cleanup ()
-  "Cleanup after `flymake-simple-make-java-init' -- delete temp file and dirs."
-  (flymake-safe-delete-file flymake-temp-source-file-name)
-  (when flymake-temp-source-file-name
-    (flymake-delete-temp-directory
-     (file-name-directory flymake-temp-source-file-name))))
+(defun flymake-proc-simple-java-cleanup ()
+  "Cleanup after `flymake-proc-simple-make-java-init' -- delete temp file and dirs."
+  (flymake-proc--safe-delete-file flymake-proc--temp-source-file-name)
+  (when flymake-proc--temp-source-file-name
+    (flymake-proc--delete-temp-directory
+     (file-name-directory flymake-proc--temp-source-file-name))))
 
 ;;;; perl-specific init-cleanup routines
-(defun flymake-perl-init ()
-  (let* ((temp-file   (flymake-init-create-temp-buffer-copy
-                       'flymake-create-temp-inplace))
+(defun flymake-proc-perl-init ()
+  (let* ((temp-file   (flymake-proc-init-create-temp-buffer-copy
+                       'flymake-proc-create-temp-inplace))
 	 (local-file  (file-relative-name
                        temp-file
                        (file-name-directory buffer-file-name))))
     (list "perl" (list "-wc " local-file))))
 
 ;;;; php-specific init-cleanup routines
-(defun flymake-php-init ()
-  (let* ((temp-file   (flymake-init-create-temp-buffer-copy
-                       'flymake-create-temp-inplace))
+(defun flymake-proc-php-init ()
+  (let* ((temp-file   (flymake-proc-init-create-temp-buffer-copy
+                       'flymake-proc-create-temp-inplace))
 	 (local-file  (file-relative-name
                        temp-file
                        (file-name-directory buffer-file-name))))
     (list "php" (list "-f" local-file "-l"))))
 
 ;;;; tex-specific init-cleanup routines
-(defun flymake-get-tex-args (file-name)
+(defun flymake-proc--get-tex-args (file-name)
   ;;(list "latex" (list "-c-style-errors" file-name))
   (list "texify" (list "--pdf" "--tex-option=-c-style-errors" file-name)))
 
-(defun flymake-simple-tex-init ()
-  (flymake-get-tex-args (flymake-init-create-temp-buffer-copy 'flymake-create-temp-inplace)))
+(defun flymake-proc-simple-tex-init ()
+  (flymake-proc--get-tex-args (flymake-proc-init-create-temp-buffer-copy 'flymake-proc-create-temp-inplace)))
 
 ;; Perhaps there should be a buffer-local variable flymake-master-file
 ;; that people can set to override this stuff.  Could inherit from
 ;; the similar AUCTeX variable.
-(defun flymake-master-tex-init ()
-  (let* ((temp-master-file-name (flymake-init-create-temp-source-and-master-buffer-copy
-                                 'flymake-get-include-dirs-dot 'flymake-create-temp-inplace
+(defun flymake-proc-master-tex-init ()
+  (let* ((temp-master-file-name (flymake-proc--init-create-temp-source-and-master-buffer-copy
+                                 'flymake-proc-get-include-dirs-dot 'flymake-proc-create-temp-inplace
 				 '("\\.tex\\'")
 				 "[ \t]*\\in\\(?:put\\|clude\\)[ \t]*{\\(.*%s\\)}")))
     (when temp-master-file-name
-      (flymake-get-tex-args temp-master-file-name))))
+      (flymake-proc--get-tex-args temp-master-file-name))))
 
-(defun flymake-get-include-dirs-dot (_base-dir)
+(defun flymake-proc--get-include-dirs-dot (_base-dir)
   '("."))
 
 ;;;; xml-specific init-cleanup routines
-(defun flymake-xml-init ()
-  (list flymake-xml-program
-        (list "val" (flymake-init-create-temp-buffer-copy
-                     'flymake-create-temp-inplace))))
+(defun flymake-proc-xml-init ()
+  (list flymake-proc-xml-program
+        (list "val" (flymake-proc-init-create-temp-buffer-copy
+                     'flymake-proc-create-temp-inplace))))
 
 
 ;;;; Hook onto flymake-ui
+(add-hook 'flymake-diagnostic-functions 'flymake-proc-legacy-flymake)
+
+
+;;;;
+
+(progn
+  (define-obsolete-variable-alias 'flymake-compilation-prevents-syntax-check
+    'flymake-proc-compilation-prevents-syntax-check "26.1")
+  (define-obsolete-variable-alias 'flymake-xml-program
+    'flymake-proc-xml-program "26.1")
+  (define-obsolete-variable-alias 'flymake-master-file-dirs
+    'flymake-proc-master-file-dirs "26.1")
+  (define-obsolete-variable-alias 'flymake-master-file-count-limit
+    'flymake-proc-master-file-count-limit "26.1"
+    "Max number of master files to check.")
+  (define-obsolete-variable-alias 'flymake-allowed-file-name-masks
+    'flymake-proc-allowed-file-name-masks "26.1")
+  (define-obsolete-variable-alias 'flymake-check-file-limit
+    'flymake-proc-check-file-limit "26.1")
+  (define-obsolete-function-alias 'flymake-reformat-err-line-patterns-from-compile-el
+    'flymake-proc-reformat-err-line-patterns-from-compile-el "26.1")
+  (define-obsolete-variable-alias 'flymake-err-line-patterns
+    'flymake-proc-err-line-patterns "26.1")
+  (define-obsolete-function-alias 'flymake-parse-line
+    'flymake-proc-parse-line "26.1")
+  (define-obsolete-function-alias 'flymake-get-include-dirs
+    'flymake-proc-get-include-dirs "26.1")
+  (define-obsolete-function-alias 'flymake-stop-all-syntax-checks
+    'flymake-proc-stop-all-syntax-checks "26.1")
+  (define-obsolete-function-alias 'flymake-compile
+    'flymake-proc-compile "26.1")
+  (define-obsolete-function-alias 'flymake-create-temp-inplace
+    'flymake-proc-create-temp-inplace "26.1")
+  (define-obsolete-function-alias 'flymake-create-temp-with-folder-structure
+    'flymake-proc-create-temp-with-folder-structure "26.1")
+  (define-obsolete-function-alias 'flymake-init-create-temp-buffer-copy
+    'flymake-proc-init-create-temp-buffer-copy "26.1")
+  (define-obsolete-function-alias 'flymake-simple-cleanup
+    'flymake-proc-simple-cleanup "26.1")
+  (define-obsolete-function-alias 'flymake-get-real-file-name
+    'flymake-proc-get-real-file-name "26.1")
+  (define-obsolete-function-alias 'flymake-master-cleanup
+    'flymake-proc-master-cleanup "26.1")
+  (define-obsolete-function-alias 'flymake-get-make-cmdline
+    'flymake-proc-get-make-cmdline "26.1")
+  (define-obsolete-function-alias 'flymake-get-ant-cmdline
+    'flymake-proc-get-ant-cmdline "26.1")
+  (define-obsolete-function-alias 'flymake-simple-make-init-impl
+    'flymake-proc-simple-make-init-impl "26.1")
+  (define-obsolete-function-alias 'flymake-simple-make-init
+    'flymake-proc-simple-make-init "26.1")
+  (define-obsolete-function-alias 'flymake-master-make-init
+    'flymake-proc-master-make-init "26.1")
+  (define-obsolete-function-alias 'flymake-find-make-buildfile
+    'flymake-proc--find-make-buildfile "26.1")
+  (define-obsolete-function-alias 'flymake-master-make-header-init
+    'flymake-proc-master-make-header-init "26.1")
+  (define-obsolete-function-alias 'flymake-simple-make-java-init
+    'flymake-proc-simple-make-java-init "26.1")
+  (define-obsolete-function-alias 'flymake-simple-ant-java-init
+    'flymake-proc-simple-ant-java-init "26.1")
+  (define-obsolete-function-alias 'flymake-simple-java-cleanup
+    'flymake-proc-simple-java-cleanup "26.1")
+  (define-obsolete-function-alias 'flymake-perl-init
+    'flymake-proc-perl-init "26.1")
+  (define-obsolete-function-alias 'flymake-php-init
+    'flymake-proc-php-init "26.1")
+  (define-obsolete-function-alias 'flymake-simple-tex-init
+    'flymake-proc-simple-tex-init "26.1")
+  (define-obsolete-function-alias 'flymake-master-tex-init
+    'flymake-proc-master-tex-init "26.1")
+  (define-obsolete-function-alias 'flymake-xml-init
+    'flymake-proc-xml-init "26.1"))
+
 
-(add-to-list 'flymake-backends
-             `(flymake-proc-can-syntax-check-buffer
-               .
-               flymake-proc-start-syntax-check))
 
 (provide 'flymake-proc)
 ;;; flymake-proc.el ends here
diff --git a/lisp/progmodes/flymake-ui.el b/lisp/progmodes/flymake-ui.el
deleted file mode 100644
index bf5218c41d2..00000000000
--- a/lisp/progmodes/flymake-ui.el
+++ /dev/null
@@ -1,634 +0,0 @@
-;;; flymake-ui.el --- A universal on-the-fly syntax checker  -*- lexical-binding: t; -*-
-
-;; Copyright (C) 2003-2017 Free Software Foundation, Inc.
-
-;; Author:  Pavel Kobyakov <pk_at_work@yahoo.com>
-;; Maintainer: Leo Liu <sdl.web@gmail.com>
-;; Version: 0.3
-;; Keywords: c languages tools
-
-;; This file is part of GNU Emacs.
-
-;; GNU Emacs 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.
-
-;; GNU Emacs 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 GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
-
-;;; Commentary:
-;;
-;; Flymake is a minor Emacs mode performing on-the-fly syntax checks.xo
-;;
-;; This file contains the UI for displaying and interacting with the
-;; results of such checks, as well as entry points for backends to
-;; hook on to. Backends are sources of diagnostic info.
-;;
-;;; Code:
-
-(eval-when-compile (require 'cl-lib))
-
-(defgroup flymake nil
-  "Universal on-the-fly syntax checker."
-  :version "23.1"
-  :link '(custom-manual "(flymake) Top")
-  :group 'tools)
-
-(defcustom flymake-error-bitmap '(exclamation-mark error)
-  "Bitmap (a symbol) used in the fringe for indicating errors.
-The value may also be a list of two elements where the second
-element specifies the face for the bitmap.  For possible bitmap
-symbols, see `fringe-bitmaps'.  See also `flymake-warning-bitmap'.
-
-The option `flymake-fringe-indicator-position' controls how and where
-this is used."
-  :group 'flymake
-  :version "24.3"
-  :type '(choice (symbol :tag "Bitmap")
-                 (list :tag "Bitmap and face"
-                       (symbol :tag "Bitmap")
-                       (face :tag "Face"))))
-
-(defcustom flymake-warning-bitmap 'question-mark
-  "Bitmap (a symbol) used in the fringe for indicating warnings.
-The value may also be a list of two elements where the second
-element specifies the face for the bitmap.  For possible bitmap
-symbols, see `fringe-bitmaps'.  See also `flymake-error-bitmap'.
-
-The option `flymake-fringe-indicator-position' controls how and where
-this is used."
-  :group 'flymake
-  :version "24.3"
-  :type '(choice (symbol :tag "Bitmap")
-                 (list :tag "Bitmap and face"
-                       (symbol :tag "Bitmap")
-                       (face :tag "Face"))))
-
-(defcustom flymake-fringe-indicator-position 'left-fringe
-  "The position to put flymake fringe indicator.
-The value can be nil (do not use indicators), `left-fringe' or `right-fringe'.
-See `flymake-error-bitmap' and `flymake-warning-bitmap'."
-  :group 'flymake
-  :version "24.3"
-  :type '(choice (const left-fringe)
-		 (const right-fringe)
-		 (const :tag "No fringe indicators" nil)))
-
-(defcustom flymake-start-syntax-check-on-newline t
-  "Start syntax check if newline char was added/removed from the buffer."
-  :group 'flymake
-  :type 'boolean)
-
-(defcustom flymake-no-changes-timeout 0.5
-  "Time to wait after last change before starting compilation."
-  :group 'flymake
-  :type 'number)
-
-(defcustom flymake-gui-warnings-enabled t
-  "Enables/disables GUI warnings."
-  :group 'flymake
-  :type 'boolean)
-(make-obsolete-variable 'flymake-gui-warnings-enabled
-			"it no longer has any effect." "26.1")
-
-(defcustom flymake-start-syntax-check-on-find-file t
-  "Start syntax check on find file."
-  :group 'flymake
-  :type 'boolean)
-
-(defcustom flymake-log-level -1
-  "Logging level, only messages with level lower or equal will be logged.
--1 = NONE, 0 = ERROR, 1 = WARNING, 2 = INFO, 3 = DEBUG"
-  :group 'flymake
-  :type 'integer)
-
-(defcustom flymake-backends '()
-  "Ordered list of backends providing syntax check information for a buffer.
-Value is an alist of conses (PREDICATE . CHECKER). Both PREDICATE
-and CHECKER are functions called with a single argument, the
-buffer in which `flymake-mode' was enabled. PREDICATE is expected
-to (quickly) return t or nil if the buffer can be syntax checked
-by CHECKER, which in can performs more morose operations,
-possibly asynchronously."
-  :group 'flymake
-  :type 'alist)
-
-(defvar-local flymake-timer nil
-  "Timer for starting syntax check.")
-
-(defvar-local flymake-last-change-time nil
-  "Time of last buffer change.")
-
-(defvar-local flymake-check-start-time nil
-  "Time at which syntax check was started.")
-
-(defvar-local flymake-check-was-interrupted nil
-  "Non-nil if syntax check was killed by `flymake-compile'.")
-
-(defvar-local flymake-err-info nil
-  "Sorted list of line numbers and lists of err info in the form (file, err-text).")
-
-(defvar-local flymake-new-err-info nil
-  "Same as `flymake-err-info', effective when a syntax check is in progress.")
-
-(defun flymake-log (level text &rest args)
-  "Log a message at level LEVEL.
-If LEVEL is higher than `flymake-log-level', the message is
-ignored.  Otherwise, it is printed using `message'.
-TEXT is a format control string, and the remaining arguments ARGS
-are the string substitutions (see the function `format')."
-  (if (<= level flymake-log-level)
-      (let* ((msg (apply #'format-message text args)))
-	(message "%s" msg))))
-
-(defun flymake-ins-after (list pos val)
-  "Insert VAL into LIST after position POS.
-POS counts from zero."
-  (let ((tmp (copy-sequence list)))
-    (setcdr (nthcdr pos tmp) (cons val (nthcdr (1+ pos) tmp)))
-    tmp))
-
-(defun flymake-set-at (list pos val)
-  "Set VAL at position POS in LIST.
-POS counts from zero."
-  (let ((tmp (copy-sequence list)))
-    (setcar (nthcdr pos tmp) val)
-    tmp))
-
-(defun flymake-er-make-er (line-no line-err-info-list)
-  (list line-no line-err-info-list))
-
-(defun flymake-er-get-line (err-info)
-  (nth 0 err-info))
-
-(defun flymake-er-get-line-err-info-list (err-info)
-  (nth 1 err-info))
-
-(cl-defstruct (flymake-ler
-            (:constructor nil)
-            (:constructor flymake-ler-make-ler (file line type text &optional full-file)))
-  file line type text full-file)
-
-(defun flymake-ler-set-file (line-err-info file)
-  (flymake-ler-make-ler file
-			(flymake-ler-line line-err-info)
-			(flymake-ler-type line-err-info)
-			(flymake-ler-text line-err-info)
-			(flymake-ler-full-file line-err-info)))
-
-(defun flymake-ler-set-full-file (line-err-info full-file)
-  (flymake-ler-make-ler (flymake-ler-file line-err-info)
-			(flymake-ler-line line-err-info)
-			(flymake-ler-type line-err-info)
-			(flymake-ler-text line-err-info)
-			full-file))
-
-(defun flymake-ler-set-line (line-err-info line)
-  (flymake-ler-make-ler (flymake-ler-file line-err-info)
-			line
-			(flymake-ler-type line-err-info)
-			(flymake-ler-text line-err-info)
-			(flymake-ler-full-file line-err-info)))
-
-(defun flymake-get-line-err-count (line-err-info-list type)
-  "Return number of errors of specified TYPE.
-Value of TYPE is either \"e\" or \"w\"."
-  (let* ((idx        0)
-	 (count      (length line-err-info-list))
-	 (err-count  0))
-
-    (while (< idx count)
-      (when (equal type (flymake-ler-type (nth idx line-err-info-list)))
-	(setq err-count (1+ err-count)))
-      (setq idx (1+ idx)))
-    err-count))
-
-(defun flymake-get-err-count (err-info-list type)
-  "Return number of errors of specified TYPE for ERR-INFO-LIST."
-  (let* ((idx        0)
-	 (count      (length err-info-list))
-	 (err-count  0))
-    (while (< idx count)
-      (setq err-count (+ err-count (flymake-get-line-err-count (nth 1 (nth idx err-info-list)) type)))
-      (setq idx (1+ idx)))
-    err-count))
-
-(defun flymake-highlight-err-lines (err-info-list)
-  "Highlight error lines in BUFFER using info from ERR-INFO-LIST."
-  (save-excursion
-    (dolist (err err-info-list)
-      (flymake-highlight-line (car err) (nth 1 err)))))
-
-(defun flymake-overlay-p (ov)
-  "Determine whether overlay OV was created by flymake."
-  (and (overlayp ov) (overlay-get ov 'flymake-overlay)))
-
-(defun flymake-make-overlay (beg end tooltip-text face bitmap)
-  "Allocate a flymake overlay in range BEG and END."
-  (when (not (flymake-region-has-flymake-overlays beg end))
-    (let ((ov (make-overlay beg end nil t))
-	  (fringe (and flymake-fringe-indicator-position
-		       (propertize "!" 'display
-				   (cons flymake-fringe-indicator-position
-					 (if (listp bitmap)
-					     bitmap
-					   (list bitmap)))))))
-      (overlay-put ov 'face           face)
-      (overlay-put ov 'help-echo      tooltip-text)
-      (overlay-put ov 'flymake-overlay  t)
-      (overlay-put ov 'priority 100)
-      (overlay-put ov 'evaporate t)
-      (overlay-put ov 'before-string fringe)
-      ;;+(flymake-log 3 "created overlay %s" ov)
-      ov)
-    (flymake-log 3 "created an overlay at (%d-%d)" beg end)))
-
-(defun flymake-delete-own-overlays ()
-  "Delete all flymake overlays in BUFFER."
-  (dolist (ol (overlays-in (point-min) (point-max)))
-    (when (flymake-overlay-p ol)
-      (delete-overlay ol)
-      ;;+(flymake-log 3 "deleted overlay %s" ol)
-      )))
-
-(defun flymake-region-has-flymake-overlays (beg end)
-  "Check if region specified by BEG and END has overlay.
-Return t if it has at least one flymake overlay, nil if no overlay."
-  (let ((ov                  (overlays-in beg end))
-	(has-flymake-overlays  nil))
-    (while (consp ov)
-      (when (flymake-overlay-p (car ov))
-	(setq has-flymake-overlays t))
-      (setq ov (cdr ov)))
-    has-flymake-overlays))
-
-(defface flymake-errline
-  '((((supports :underline (:style wave)))
-     :underline (:style wave :color "Red1"))
-    (t
-     :inherit error))
-  "Face used for marking error lines."
-  :version "24.4"
-  :group 'flymake)
-
-(defface flymake-warnline
-  '((((supports :underline (:style wave)))
-     :underline (:style wave :color "DarkOrange"))
-    (t
-     :inherit warning))
-  "Face used for marking warning lines."
-  :version "24.4"
-  :group 'flymake)
-
-(defun flymake-highlight-line (line-no line-err-info-list)
-  "Highlight line LINE-NO in current buffer.
-Perhaps use text from LINE-ERR-INFO-LIST to enhance highlighting."
-  (goto-char (point-min))
-  (forward-line (1- line-no))
-  (pcase-let* ((beg (progn (back-to-indentation) (point)))
-               (end (progn
-                      (end-of-line)
-                      (skip-chars-backward " \t\f\t\n" beg)
-                      (if (eq (point) beg)
-                          (line-beginning-position 2)
-                        (point))))
-               (tooltip-text (mapconcat #'flymake-ler-text line-err-info-list "\n"))
-               (`(,face ,bitmap)
-                (if (> (flymake-get-line-err-count line-err-info-list "e") 0)
-                    (list 'flymake-errline flymake-error-bitmap)
-                  (list 'flymake-warnline flymake-warning-bitmap))))
-    (flymake-make-overlay beg end tooltip-text face bitmap)))
-
-(defun flymake-find-err-info (err-info-list line-no)
-  "Find (line-err-info-list pos) for specified LINE-NO."
-  (if err-info-list
-      (let* ((line-err-info-list  nil)
-	     (pos       0)
-	     (count     (length err-info-list)))
-
-	(while (and (< pos count) (< (car (nth pos err-info-list)) line-no))
-	  (setq pos (1+ pos)))
-	(when (and (< pos count) (equal (car (nth pos err-info-list)) line-no))
-	  (setq line-err-info-list (flymake-er-get-line-err-info-list (nth pos err-info-list))))
-	(list line-err-info-list pos))
-    '(nil 0)))
-
-(defun flymake-line-err-info-is-less-or-equal (line-one line-two)
-  (or (string< (flymake-ler-type line-one) (flymake-ler-type line-two))
-      (and (string= (flymake-ler-type line-one) (flymake-ler-type line-two))
-	   (not (flymake-ler-file line-one)) (flymake-ler-file line-two))
-      (and (string= (flymake-ler-type line-one) (flymake-ler-type line-two))
-	   (or (and      (flymake-ler-file line-one)       (flymake-ler-file line-two))
-	       (and (not (flymake-ler-file line-one)) (not (flymake-ler-file line-two)))))))
-
-(defun flymake-add-line-err-info (line-err-info-list line-err-info)
-  "Update LINE-ERR-INFO-LIST with the error LINE-ERR-INFO.
-For the format of LINE-ERR-INFO, see `flymake-ler-make-ler'.
-The new element is inserted in the proper position, according to
-the predicate `flymake-line-err-info-is-less-or-equal'.
-The updated value of LINE-ERR-INFO-LIST is returned."
-  (if (not line-err-info-list)
-      (list line-err-info)
-    (let* ((count  (length line-err-info-list))
-	   (idx    0))
-      (while (and (< idx count) (flymake-line-err-info-is-less-or-equal (nth idx line-err-info-list) line-err-info))
-	(setq idx (1+ idx)))
-      (cond ((equal 0     idx)    (setq line-err-info-list (cons line-err-info line-err-info-list)))
-	    (t                    (setq line-err-info-list (flymake-ins-after line-err-info-list (1- idx) line-err-info))))
-      line-err-info-list)))
-
-(defun flymake-add-err-info (err-info-list line-err-info)
-  "Update ERR-INFO-LIST with the error LINE-ERR-INFO, preserving sort order.
-Returns the updated value of ERR-INFO-LIST.
-For the format of ERR-INFO-LIST, see `flymake-err-info'.
-For the format of LINE-ERR-INFO, see `flymake-ler-make-ler'."
-  (let* ((line-no             (if (flymake-ler-file line-err-info) 1 (flymake-ler-line line-err-info)))
-	 (info-and-pos        (flymake-find-err-info err-info-list line-no))
-	 (exists              (car info-and-pos))
-	 (pos                 (nth 1 info-and-pos))
-	 (line-err-info-list  nil)
-	 (err-info            nil))
-
-    (if exists
-	(setq line-err-info-list (flymake-er-get-line-err-info-list (car (nthcdr pos err-info-list)))))
-    (setq line-err-info-list (flymake-add-line-err-info line-err-info-list line-err-info))
-
-    (setq err-info (flymake-er-make-er line-no line-err-info-list))
-    (cond (exists             (setq err-info-list (flymake-set-at err-info-list pos err-info)))
-	  ((equal 0 pos)      (setq err-info-list (cons err-info err-info-list)))
-	  (t                  (setq err-info-list (flymake-ins-after err-info-list (1- pos) err-info))))
-    err-info-list))
-
-(defvar-local flymake-is-running nil
-  "If t, flymake syntax check process is running for the current buffer.")
-
-(defun flymake-on-timer-event (buffer)
-  "Start a syntax check for buffer BUFFER if necessary."
-  (when (buffer-live-p buffer)
-    (with-current-buffer buffer
-      (when (and (not flymake-is-running)
-		 flymake-last-change-time
-		 (> (- (float-time) flymake-last-change-time)
-                    flymake-no-changes-timeout))
-
-	(setq flymake-last-change-time nil)
-	(flymake-log 3 "starting syntax check as more than 1 second passed since last change")
-	(flymake--start-syntax-check)))))
-
-(define-obsolete-function-alias 'flymake-display-err-menu-for-current-line
-  'flymake-popup-current-error-menu "24.4")
-
-(defun flymake-popup-current-error-menu (&optional event)
-  "Pop up a menu with errors/warnings for current line."
-  (interactive (list last-nonmenu-event))
-  (let* ((line-no (line-number-at-pos))
-         (errors (or (car (flymake-find-err-info flymake-err-info line-no))
-                     (user-error "No errors for current line")))
-         (menu (mapcar (lambda (x)
-                         (if (flymake-ler-file x)
-                             (cons (format "%s - %s(%d)"
-                                           (flymake-ler-text x)
-                                           (flymake-ler-file x)
-                                           (flymake-ler-line x))
-                                   x)
-                           (list (flymake-ler-text x))))
-                       errors))
-         (event (if (mouse-event-p event)
-                    event
-                  (list 'mouse-1 (posn-at-point))))
-         (title (format "Line %d: %d error(s), %d warning(s)"
-                        line-no
-                        (flymake-get-line-err-count errors "e")
-                        (flymake-get-line-err-count errors "w")))
-         (choice (x-popup-menu event (list title (cons "" menu)))))
-    (flymake-log 3 "choice=%s" choice)
-    (when choice
-      (flymake-goto-file-and-line (flymake-ler-full-file choice)
-                                  (flymake-ler-line choice)))))
-
-(defun flymake-goto-file-and-line (file line)
-  "Try to get buffer for FILE and goto line LINE in it."
-  (if (not (file-exists-p file))
-      (flymake-log 1 "File %s does not exist" file)
-    (find-file file)
-    (goto-char (point-min))
-    (forward-line (1- line))))
-
-;; flymake minor mode declarations
-(defvar-local flymake-mode-line nil)
-(defvar-local flymake-mode-line-e-w nil)
-(defvar-local flymake-mode-line-status nil)
-
-(defun flymake-report-status (e-w &optional status)
-  "Show status in mode line."
-  (when e-w
-    (setq flymake-mode-line-e-w e-w))
-  (when status
-    (setq flymake-mode-line-status status))
-  (let* ((mode-line " Flymake"))
-    (when (> (length flymake-mode-line-e-w) 0)
-      (setq mode-line (concat mode-line ":" flymake-mode-line-e-w)))
-    (setq mode-line (concat mode-line flymake-mode-line-status))
-    (setq flymake-mode-line mode-line)
-    (force-mode-line-update)))
-
-;; Nothing in flymake uses this at all any more, so this is just for
-;; third-party compatibility.
-(define-obsolete-function-alias 'flymake-display-warning 'message-box "26.1")
-
-(defun flymake-report-fatal-status (status warning)
-  "Display a warning and switch flymake mode off."
-  ;; This first message was always shown by default, and flymake-log
-  ;; does nothing by default, hence the use of message.
-  ;; Another option is display-warning.
-  (if (< flymake-log-level 0)
-      (message "Flymake: %s. Flymake will be switched OFF" warning))
-  (flymake-mode 0)
-  (flymake-log 0 "switched OFF Flymake mode for buffer %s due to fatal status %s, warning %s"
-               (buffer-name) status warning))
-
-(defvar-local flymake--backend nil
-  "The currently active backend selected by `flymake-mode'")
-
-(defun flymake--can-syntax-check-buffer (buffer)
-  (let ((all flymake-backends)
-        (candidate))
-    (catch 'done
-      (while (setq candidate (pop all))
-        (when (with-current-buffer buffer (funcall (car candidate)))
-          (throw 'done (cdr candidate)))))))
-
-(defun flymake--start-syntax-check ()
-  (funcall flymake--backend))
-
-;;;###autoload
-(define-minor-mode flymake-mode nil
-  :group 'flymake :lighter flymake-mode-line
-  (cond
-
-   ;; Turning the mode ON.
-   (flymake-mode
-    (let* ((backend (flymake--can-syntax-check-buffer (current-buffer))))
-      (cond
-       ((not backend)
-        (flymake-log 2 "flymake cannot check syntax in buffer %s" (buffer-name)))
-       (t
-        (setq flymake--backend backend)
-
-        (add-hook 'after-change-functions 'flymake-after-change-function nil t)
-        (add-hook 'after-save-hook 'flymake-after-save-hook nil t)
-        (add-hook 'kill-buffer-hook 'flymake-kill-buffer-hook nil t)
-        ;;+(add-hook 'find-file-hook 'flymake-find-file-hook)
-
-        (flymake-report-status "" "")
-
-        (setq flymake-timer
-              (run-at-time nil 1 'flymake-on-timer-event (current-buffer)))
-
-        (when (and flymake-start-syntax-check-on-find-file
-                   ;; Since we write temp files in current dir, there's no point
-                   ;; trying if the directory is read-only (bug#8954).
-                   (file-writable-p (file-name-directory buffer-file-name)))
-          (with-demoted-errors
-              (flymake--start-syntax-check)))))
-      )
-    )
-
-   ;; Turning the mode OFF.
-   (t
-    (setq flymake--backend nil)
-
-    (remove-hook 'after-change-functions 'flymake-after-change-function t)
-    (remove-hook 'after-save-hook 'flymake-after-save-hook t)
-    (remove-hook 'kill-buffer-hook 'flymake-kill-buffer-hook t)
-    ;;+(remove-hook 'find-file-hook (function flymake-find-file-hook) t)
-
-    (flymake-delete-own-overlays)
-
-    (when flymake-timer
-      (cancel-timer flymake-timer)
-      (setq flymake-timer nil))
-
-    (setq flymake-is-running nil))))
-
-;; disabling flymake-mode is safe, enabling - not necessarily so
-(put 'flymake-mode 'safe-local-variable 'null)
-
-;;;###autoload
-(defun flymake-mode-on ()
-  "Turn flymake mode on."
-  (flymake-mode 1)
-  (flymake-log 1 "flymake mode turned ON for buffer %s" (buffer-name)))
-
-;;;###autoload
-(defun flymake-mode-off ()
-  "Turn flymake mode off."
-  (flymake-mode 0)
-  (flymake-log 1 "flymake mode turned OFF for buffer %s" (buffer-name)))
-
-(defun flymake-after-change-function (start stop _len)
-  "Start syntax check for current buffer if it isn't already running."
-  ;;+(flymake-log 0 "setting change time to %s" (float-time))
-  (let((new-text (buffer-substring start stop)))
-    (when (and flymake-start-syntax-check-on-newline (equal new-text "\n"))
-      (flymake-log 3 "starting syntax check as new-line has been seen")
-      (flymake--start-syntax-check))
-    (setq flymake-last-change-time (float-time))))
-
-(defun flymake-after-save-hook ()
-  (if (local-variable-p 'flymake-mode (current-buffer))	; (???) other way to determine whether flymake is active in buffer being saved?
-      (progn
-	(flymake-log 3 "starting syntax check as buffer was saved")
-	(flymake--start-syntax-check)))) ; no more mode 3. cannot start check if mode 3 (to temp copies) is active - (???)
-
-(defun flymake-kill-buffer-hook ()
-  (when flymake-timer
-    (cancel-timer flymake-timer)
-    (setq flymake-timer nil)))
-
-;;;###autoload
-(defun flymake-find-file-hook ()
-  ;;+(when flymake-start-syntax-check-on-find-file
-  ;;+    (flymake-log 3 "starting syntax check on file open")
-  ;;+    (flymake--start-syntax-check)
-  ;;+)
-  (when (and (not (local-variable-p 'flymake-mode (current-buffer)))
-	     (flymake--can-syntax-check-buffer (current-buffer)))
-    (flymake-mode)
-    (flymake-log 3 "automatically turned ON flymake mode")))
-
-(defun flymake-get-first-err-line-no (err-info-list)
-  "Return first line with error."
-  (when err-info-list
-    (flymake-er-get-line (car err-info-list))))
-
-(defun flymake-get-last-err-line-no (err-info-list)
-  "Return last line with error."
-  (when err-info-list
-    (flymake-er-get-line (nth (1- (length err-info-list)) err-info-list))))
-
-(defun flymake-get-next-err-line-no (err-info-list line-no)
-  "Return next line with error."
-  (when err-info-list
-    (let* ((count  (length err-info-list))
-	   (idx    0))
-      (while (and (< idx count) (>= line-no (flymake-er-get-line (nth idx err-info-list))))
-	(setq idx (1+ idx)))
-      (if (< idx count)
-	  (flymake-er-get-line (nth idx err-info-list))))))
-
-(defun flymake-get-prev-err-line-no (err-info-list line-no)
-  "Return previous line with error."
-  (when err-info-list
-    (let* ((count (length err-info-list)))
-      (while (and (> count 0) (<= line-no (flymake-er-get-line (nth (1- count) err-info-list))))
-	(setq count (1- count)))
-      (if (> count 0)
-	  (flymake-er-get-line (nth (1- count) err-info-list))))))
-
-(defun flymake-skip-whitespace ()
-  "Move forward until non-whitespace is reached."
-  (while (looking-at "[ \t]")
-    (forward-char)))
-
-(defun flymake-goto-line (line-no)
-  "Go to line LINE-NO, then skip whitespace."
-  (goto-char (point-min))
-  (forward-line (1- line-no))
-  (flymake-skip-whitespace))
-
-(defun flymake-goto-next-error ()
-  "Go to next error in err ring."
-  (interactive)
-  (let ((line-no (flymake-get-next-err-line-no flymake-err-info (line-number-at-pos))))
-    (when (not line-no)
-      (setq line-no (flymake-get-first-err-line-no flymake-err-info))
-      (flymake-log 1 "passed end of file"))
-    (if line-no
-	(flymake-goto-line line-no)
-      (flymake-log 1 "no errors in current buffer"))))
-
-(defun flymake-goto-prev-error ()
-  "Go to previous error in err ring."
-  (interactive)
-  (let ((line-no (flymake-get-prev-err-line-no flymake-err-info (line-number-at-pos))))
-    (when (not line-no)
-      (setq line-no (flymake-get-last-err-line-no flymake-err-info))
-      (flymake-log 1 "passed beginning of file"))
-    (if line-no
-	(flymake-goto-line line-no)
-      (flymake-log 1 "no errors in current buffer"))))
-
-(defun flymake-patch-err-text (string)
-  (if (string-match "^[\n\t :0-9]*\\(.*\\)$" string)
-      (match-string 1 string)
-    string))
-
-(provide 'flymake-ui)
-;;; flymake-ui.el ends here
diff --git a/lisp/progmodes/flymake.el b/lisp/progmodes/flymake.el
index 059bce95eed..45f0adfeba1 100644
--- a/lisp/progmodes/flymake.el
+++ b/lisp/progmodes/flymake.el
@@ -1,4 +1,4 @@
-;;; flymake.el --- a universal on-the-fly syntax checker  -*- lexical-binding: t; -*-
+;;; flymake.el --- A universal on-the-fly syntax checker  -*- lexical-binding: t; -*-
 
 ;; Copyright (C) 2003-2017 Free Software Foundation, Inc.
 
@@ -20,22 +20,964 @@
 ;; GNU General Public License for more details.
 
 ;; You should have received a copy of the GNU General Public License
-;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
+;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
 
 ;;; Commentary:
 ;;
 ;; Flymake is a minor Emacs mode performing on-the-fly syntax checks.
 ;;
-;; It collects diagnostic information for multiple sources and
-;; visually annotates the relevant lines in the buffer.
+;; Flymake collects diagnostic information for multiple sources,
+;; called backends, and visually annotates the relevant portions in
+;; the buffer.
+;;
+;; This file contains the UI for displaying and interacting with the
+;; results produced by these backends, as well as entry points for
+;; backends to hook on to.
+;;
+;; The main entry points are `flymake-mode' and `flymake-start'
+;;
+;; The docstrings of these variables are relevant to understanding how
+;; Flymake works for both the user and the backend programmer:
+;;
+;; * `flymake-diagnostic-functions'
+;; * `flymake-diagnostic-types-alist'
 ;;
-;; This file is just a stub for that loads the UI and backends, which
-;; could also be loaded separately.
-
 ;;; Code:
 
-(require 'flymake-ui)
-(require 'flymake-proc)
+(require 'cl-lib)
+(require 'thingatpt) ; end-of-thing
+(require 'warnings) ; warning-numeric-level, display-warning
+(require 'compile) ; for some faces
+(require 'subr-x) ; when-let*, if-let*, hash-table-keys, hash-table-values
+
+(defgroup flymake nil
+  "Universal on-the-fly syntax checker."
+  :version "23.1"
+  :link '(custom-manual "(flymake) Top")
+  :group 'tools)
+
+(defcustom flymake-error-bitmap '(flymake-double-exclamation-mark
+                                  compilation-error)
+  "Bitmap (a symbol) used in the fringe for indicating errors.
+The value may also be a list of two elements where the second
+element specifies the face for the bitmap.  For possible bitmap
+symbols, see `fringe-bitmaps'.  See also `flymake-warning-bitmap'.
+
+The option `flymake-fringe-indicator-position' controls how and where
+this is used."
+  :version "24.3"
+  :type '(choice (symbol :tag "Bitmap")
+                 (list :tag "Bitmap and face"
+                       (symbol :tag "Bitmap")
+                       (face :tag "Face"))))
+
+(defcustom flymake-warning-bitmap '(exclamation-mark compilation-warning)
+  "Bitmap (a symbol) used in the fringe for indicating warnings.
+The value may also be a list of two elements where the second
+element specifies the face for the bitmap.  For possible bitmap
+symbols, see `fringe-bitmaps'.  See also `flymake-error-bitmap'.
+
+The option `flymake-fringe-indicator-position' controls how and where
+this is used."
+  :version "24.3"
+  :type '(choice (symbol :tag "Bitmap")
+                 (list :tag "Bitmap and face"
+                       (symbol :tag "Bitmap")
+                       (face :tag "Face"))))
+
+(defcustom flymake-note-bitmap '(exclamation-mark compilation-info)
+  "Bitmap (a symbol) used in the fringe for indicating info notes.
+The value may also be a list of two elements where the second
+element specifies the face for the bitmap.  For possible bitmap
+symbols, see `fringe-bitmaps'.  See also `flymake-error-bitmap'.
+
+The option `flymake-fringe-indicator-position' controls how and where
+this is used."
+  :version "26.1"
+  :type '(choice (symbol :tag "Bitmap")
+                 (list :tag "Bitmap and face"
+                       (symbol :tag "Bitmap")
+                       (face :tag "Face"))))
+
+(defcustom flymake-fringe-indicator-position 'left-fringe
+  "The position to put Flymake fringe indicator.
+The value can be nil (do not use indicators), `left-fringe' or `right-fringe'.
+See `flymake-error-bitmap' and `flymake-warning-bitmap'."
+  :version "24.3"
+  :type '(choice (const left-fringe)
+		 (const right-fringe)
+		 (const :tag "No fringe indicators" nil)))
+
+(defcustom flymake-start-syntax-check-on-newline t
+  "Start syntax check if newline char was added/removed from the buffer."
+  :type 'boolean)
+
+(defcustom flymake-no-changes-timeout 0.5
+  "Time to wait after last change before automatically checking buffer.
+If nil, never start checking buffer automatically like this."
+  :type 'number)
+
+(defcustom flymake-gui-warnings-enabled t
+  "Enables/disables GUI warnings."
+  :type 'boolean)
+(make-obsolete-variable 'flymake-gui-warnings-enabled
+			"it no longer has any effect." "26.1")
+
+(defcustom flymake-start-syntax-check-on-find-file t
+  "Start syntax check on find file."
+  :type 'boolean)
+
+(defcustom flymake-log-level -1
+  "Obsolete and ignored variable."
+  :type 'integer)
+(make-obsolete-variable 'flymake-log-level
+			"it is superseded by `warning-minimum-log-level.'"
+                        "26.1")
+
+(defcustom flymake-wrap-around t
+  "If non-nil, moving to errors wraps around buffer boundaries."
+  :type 'boolean)
+
+(define-fringe-bitmap 'flymake-double-exclamation-mark
+  (vector #b00000000
+          #b00000000
+          #b00000000
+          #b00000000
+          #b01100110
+          #b01100110
+          #b01100110
+          #b01100110
+          #b01100110
+          #b01100110
+          #b01100110
+          #b01100110
+          #b00000000
+          #b01100110
+          #b00000000
+          #b00000000
+          #b00000000))
+
+(defvar-local flymake-timer nil
+  "Timer for starting syntax check.")
+
+(defvar-local flymake-check-start-time nil
+  "Time at which syntax check was started.")
+
+(defun flymake--log-1 (level sublog msg &rest args)
+  "Do actual work for `flymake-log'."
+  (let (;; never popup the log buffer
+        (warning-minimum-level :emergency)
+        (warning-type-format
+         (format " [%s %s]"
+                 (or sublog 'flymake)
+                 (current-buffer))))
+    (display-warning (list 'flymake sublog)
+                     (apply #'format-message msg args)
+                     (if (numberp level)
+                         (or (nth level
+                                  '(:emergency :error :warning :debug :debug) )
+                             :error)
+                       level)
+                     "*Flymake log*")))
+
+(defun flymake-switch-to-log-buffer ()
+  "Go to the *Flymake log* buffer."
+  (interactive)
+  (switch-to-buffer "*Flymake log*"))
+
+;;;###autoload
+(defmacro flymake-log (level msg &rest args)
+  "Log, at level LEVEL, the message MSG formatted with ARGS.
+LEVEL is passed to `display-warning', which is used to display
+the warning.  If this form is included in a byte-compiled file,
+the generated warning contains an indication of the file that
+generated it."
+  (let* ((compile-file (and (boundp 'byte-compile-current-file)
+                            (symbol-value 'byte-compile-current-file)))
+         (sublog (if (and
+                      compile-file
+                      (not load-file-name))
+                     (intern
+                      (file-name-nondirectory
+                       (file-name-sans-extension compile-file))))))
+    `(flymake--log-1 ,level ',sublog ,msg ,@args)))
+
+(defun flymake-error (text &rest args)
+  "Format TEXT with ARGS and signal an error for Flymake."
+  (let ((msg (apply #'format-message text args)))
+    (flymake-log :error msg)
+    (error (concat "[Flymake] " msg))))
+
+(cl-defstruct (flymake--diag
+               (:constructor flymake--diag-make))
+  buffer beg end type text backend)
+
+;;;###autoload
+(defun flymake-make-diagnostic (buffer
+                                beg
+                                end
+                                type
+                                text)
+  "Make a Flymake diagnostic for BUFFER's region from BEG to END.
+TYPE is a key to `flymake-diagnostic-types-alist' and TEXT is a
+description of the problem detected in this region."
+  (flymake--diag-make :buffer buffer :beg beg :end end :type type :text text))
+
+(cl-defun flymake--overlays (&key beg end filter compare key)
+  "Get flymake-related overlays.
+If BEG is non-nil and END is nil, consider only `overlays-at'
+BEG. Otherwise consider `overlays-in' the region comprised by BEG
+and END, defaulting to the whole buffer.  Remove all that do not
+verify FILTER, a function, and sort them by COMPARE (using KEY)."
+  (save-restriction
+    (widen)
+    (let ((ovs (cl-remove-if-not
+                (lambda (ov)
+                  (and (overlay-get ov 'flymake)
+                       (or (not filter)
+                           (funcall filter ov))))
+                (if (and beg (null end))
+                    (overlays-at beg t)
+                  (overlays-in (or beg (point-min))
+                               (or end (point-max)))))))
+      (if compare
+          (cl-sort ovs compare :key (or key
+                                        #'identity))
+        ovs))))
+
+(defun flymake-delete-own-overlays (&optional filter)
+  "Delete all Flymake overlays in BUFFER."
+  (mapc #'delete-overlay (flymake--overlays :filter filter)))
+
+(defface flymake-error
+  '((((supports :underline (:style wave)))
+     :underline (:style wave :color "Red1"))
+    (t
+     :inherit error))
+  "Face used for marking error regions."
+  :version "24.4")
+
+(defface flymake-warning
+  '((((supports :underline (:style wave)))
+     :underline (:style wave :color "deep sky blue"))
+    (t
+     :inherit warning))
+  "Face used for marking warning regions."
+  :version "24.4")
+
+(defface flymake-note
+  '((((supports :underline (:style wave)))
+     :underline (:style wave :color "yellow green"))
+    (t
+     :inherit warning))
+  "Face used for marking note regions."
+  :version "26.1")
+
+(define-obsolete-face-alias 'flymake-warnline 'flymake-warning "26.1")
+(define-obsolete-face-alias 'flymake-errline 'flymake-error "26.1")
+
+;;;###autoload
+(defun flymake-diag-region (buffer line &optional col)
+  "Compute BUFFER's region (BEG . END) corresponding to LINE and COL.
+If COL is nil, return a region just for LINE.  Return nil if the
+region is invalid."
+  (condition-case-unless-debug _err
+      (with-current-buffer buffer
+        (let ((line (min (max line 1)
+                         (line-number-at-pos (point-max) 'absolute))))
+          (save-excursion
+            (goto-char (point-min))
+            (forward-line (1- line))
+            (cl-flet ((fallback-bol
+                       () (progn (back-to-indentation) (point)))
+                      (fallback-eol
+                       (beg)
+                       (progn
+                         (end-of-line)
+                         (skip-chars-backward " \t\f\t\n" beg)
+                         (if (eq (point) beg)
+                             (line-beginning-position 2)
+                           (point)))))
+              (if (and col (cl-plusp col))
+                  (let* ((beg (progn (forward-char (1- col))
+                                     (point)))
+                         (sexp-end (ignore-errors (end-of-thing 'sexp)))
+                         (end (or (and sexp-end
+                                       (not (= sexp-end beg))
+                                       sexp-end)
+                                  (ignore-errors (goto-char (1+ beg)))))
+                         (safe-end (or end
+                                       (fallback-eol beg))))
+                    (cons (if end beg (fallback-bol))
+                          safe-end))
+                (let* ((beg (fallback-bol))
+                       (end (fallback-eol beg)))
+                  (cons beg end)))))))
+    (error (flymake-error "Invalid region line=%s col=%s" line col))))
+
+(defvar flymake-diagnostic-functions nil
+  "Special hook of Flymake backends that check a buffer.
+
+The functions in this hook diagnose problems in a buffer’s
+contents and provide information to the Flymake user interface
+about where and how to annotate problems diagnosed in a buffer.
+
+Whenever Flymake or the user decides to re-check the buffer, each
+function is called with an arbitrary number of arguments:
+
+* the first argument is always REPORT-FN, a callback function
+  detailed below;
+
+* the remaining arguments are keyword-value pairs in the
+  form (:KEY VALUE :KEY2 VALUE2...).  Currently, Flymake provides
+  no such arguments, but backend functions must be prepared to
+  accept and possibly ignore any number of them.
+
+Backend functions are expected to initiate the buffer check, but
+aren't required to complete it check before exiting: if the
+computation involved is expensive, especially for large buffers,
+that task can be scheduled for the future using asynchronous
+processes or other asynchronous mechanisms.
+
+In any case, backend functions are expected to return quickly or
+signal an error, in which case the backend is disabled.  Flymake
+will not try disabled backends again for any future checks of
+this buffer.  Certain commands, like turning `flymake-mode' off
+and on again, reset the list of disabled backends.
+
+If the function returns, Flymake considers the backend to be
+\"running\". If it has not done so already, the backend is
+expected to call the function REPORT-FN with a single argument
+REPORT-ACTION also followed by an optional list of keyword-value
+pairs in the form (:REPORT-KEY VALUE :REPORT-KEY2 VALUE2...).
+
+Currently accepted values for REPORT-ACTION are:
+
+* A (possibly empty) list of diagnostic objects created with
+  `flymake-make-diagnostic', causing Flymake to annotate the
+  buffer with this information.
+
+  A backend may call REPORT-FN repeatedly in this manner, but
+  only until Flymake considers that the most recently requested
+  buffer check is now obsolete because, say, buffer contents have
+  changed in the meantime. The backend is only given notice of
+  this via a renewed call to the backend function. Thus, to
+  prevent making obsolete reports and wasting resources, backend
+  functions should first cancel any ongoing processing from
+  previous calls.
+
+* The symbol `:panic', signaling that the backend has encountered
+  an exceptional situation and should be disabled.
+
+Currently accepted REPORT-KEY arguments are:
+
+* ‘:explanation’: value should give user-readable details of
+  the situation encountered, if any.
+
+* ‘:force’: value should be a boolean suggesting that Flymake
+  consider the report even if it was somehow unexpected.")
+
+(defvar flymake-diagnostic-types-alist
+  `((:error
+     . ((flymake-category . flymake-error)))
+    (:warning
+     . ((flymake-category . flymake-warning)))
+    (:note
+     . ((flymake-category . flymake-note))))
+  "Alist ((KEY . PROPS)*) of properties of Flymake diagnostic types.
+KEY designates a kind of diagnostic can be anything passed as
+`:type' to `flymake-make-diagnostic'.
+
+PROPS is an alist of properties that are applied, in order, to
+the diagnostics of the type designated by KEY.  The recognized
+properties are:
+
+* Every property pertaining to overlays, except `category' and
+  `evaporate' (see Info Node `(elisp)Overlay Properties'), used
+  to affect the appearance of Flymake annotations.
+
+* `bitmap', an image displayed in the fringe according to
+  `flymake-fringe-indicator-position'.  The value actually
+  follows the syntax of `flymake-error-bitmap' (which see).  It
+  is overridden by any `before-string' overlay property.
+
+* `severity', a non-negative integer specifying the diagnostic's
+  severity.  The higher, the more serious.  If the overlay
+  priority `priority' is not specified, `severity' is used to set
+  it and help sort overlapping overlays.
+
+* `flymake-category', a symbol whose property list is considered
+  as a default for missing values of any other properties.  This
+  is useful to backend authors when creating new diagnostic types
+  that differ from an existing type by only a few properties.")
+
+(put 'flymake-error 'face 'flymake-error)
+(put 'flymake-error 'bitmap 'flymake-error-bitmap)
+(put 'flymake-error 'severity (warning-numeric-level :error))
+(put 'flymake-error 'mode-line-face 'compilation-error)
+
+(put 'flymake-warning 'face 'flymake-warning)
+(put 'flymake-warning 'bitmap 'flymake-warning-bitmap)
+(put 'flymake-warning 'severity (warning-numeric-level :warning))
+(put 'flymake-warning 'mode-line-face 'compilation-warning)
+
+(put 'flymake-note 'face 'flymake-note)
+(put 'flymake-note 'bitmap 'flymake-note-bitmap)
+(put 'flymake-note 'severity (warning-numeric-level :debug))
+(put 'flymake-note 'mode-line-face 'compilation-info)
+
+(defun flymake--lookup-type-property (type prop &optional default)
+  "Look up PROP for TYPE in `flymake-diagnostic-types-alist'.
+If TYPE doesn't declare PROP in either
+`flymake-diagnostic-types-alist' or in the symbol of its
+associated `flymake-category' return DEFAULT."
+  (let ((alist-probe (assoc type flymake-diagnostic-types-alist)))
+    (cond (alist-probe
+           (let* ((alist (cdr alist-probe))
+                  (prop-probe (assoc prop alist)))
+             (if prop-probe
+                 (cdr prop-probe)
+               (if-let* ((cat (assoc-default 'flymake-category alist))
+                         (plist (and (symbolp cat)
+                                     (symbol-plist cat)))
+                         (cat-probe (plist-member plist prop)))
+                   (cadr cat-probe)
+                 default))))
+          (t
+           default))))
+
+(defun flymake--fringe-overlay-spec (bitmap &optional recursed)
+  (if (and (symbolp bitmap)
+           (boundp bitmap)
+           (not recursed))
+      (flymake--fringe-overlay-spec
+       (symbol-value bitmap) t)
+    (and flymake-fringe-indicator-position
+         bitmap
+         (propertize "!" 'display
+                     (cons flymake-fringe-indicator-position
+                           (if (listp bitmap)
+                               bitmap
+                             (list bitmap)))))))
+
+(defun flymake--highlight-line (diagnostic)
+  "Highlight buffer with info in DIAGNOSTIC."
+  (when-let* ((ov (make-overlay
+                   (flymake--diag-beg diagnostic)
+                   (flymake--diag-end diagnostic))))
+    ;; First set `category' in the overlay, then copy over every other
+    ;; property.
+    ;;
+    (let ((alist (assoc-default (flymake--diag-type diagnostic)
+                                flymake-diagnostic-types-alist)))
+      (overlay-put ov 'category (assoc-default 'flymake-category alist))
+      (cl-loop for (k . v) in alist
+               unless (eq k 'category)
+               do (overlay-put ov k v)))
+    ;; Now ensure some essential defaults are set
+    ;;
+    (cl-flet ((default-maybe
+                (prop value)
+                (unless (or (plist-member (overlay-properties ov) prop)
+                            (let ((cat (overlay-get ov
+                                                    'flymake-category)))
+                              (and cat
+                                   (plist-member (symbol-plist cat) prop))))
+                  (overlay-put ov prop value))))
+      (default-maybe 'bitmap 'flymake-error-bitmap)
+      (default-maybe 'face 'flymake-error)
+      (default-maybe 'before-string
+        (flymake--fringe-overlay-spec
+         (overlay-get ov 'bitmap)))
+      (default-maybe 'help-echo
+        (lambda (_window _ov pos)
+          (mapconcat
+           (lambda (ov)
+             (let ((diag (overlay-get ov 'flymake--diagnostic)))
+               (flymake--diag-text diag)))
+           (flymake--overlays :beg pos)
+           "\n")))
+      (default-maybe 'severity (warning-numeric-level :error))
+      (default-maybe 'priority (+ 100 (overlay-get ov 'severity))))
+    ;; Some properties can't be overridden.
+    ;;
+    (overlay-put ov 'evaporate t)
+    (overlay-put ov 'flymake t)
+    (overlay-put ov 'flymake--diagnostic diagnostic)))
+
+;; Nothing in Flymake uses this at all any more, so this is just for
+;; third-party compatibility.
+(define-obsolete-function-alias 'flymake-display-warning 'message-box "26.1")
+
+(defvar-local flymake--backend-state nil
+  "Buffer-local hash table of a Flymake backend's state.
+The keys to this hash table are functions as found in
+`flymake-diagnostic-functions'. The values are structures
+of the type `flymake--backend-state', with these slots:
+
+`running', a symbol to keep track of a backend's replies via its
+REPORT-FN argument. A backend is running if this key is
+present. If nil, Flymake isn't expecting any replies from the
+backend.
+
+`diags', a (possibly empty) list of recent diagnostic objects
+created by the backend with `flymake-make-diagnostic'.
+
+`reported-p', a boolean indicating if the backend has replied
+since it last was contacted.
+
+`disabled', a string with the explanation for a previous
+exceptional situation reported by the backend, nil if the
+backend is operating normally.")
+
+(cl-defstruct (flymake--backend-state
+               (:constructor flymake--make-backend-state))
+  running reported-p disabled diags)
+
+(defmacro flymake--with-backend-state (backend state-var &rest body)
+  "Bind BACKEND's STATE-VAR to its state, run BODY."
+  (declare (indent 2) (debug (sexp sexp &rest form)))
+  (let ((b (make-symbol "b")))
+    `(let* ((,b ,backend)
+            (,state-var
+             (or (gethash ,b flymake--backend-state)
+                 (puthash ,b (flymake--make-backend-state)
+                          flymake--backend-state))))
+       ,@body)))
+
+(defun flymake-is-running ()
+  "Tell if Flymake has running backends in this buffer"
+  (flymake-running-backends))
+
+(cl-defun flymake--handle-report (backend token report-action
+                                          &key explanation force
+                                          &allow-other-keys)
+  "Handle reports from BACKEND identified by TOKEN.
+BACKEND, REPORT-ACTION and EXPLANATION, and FORCE conform to the calling
+convention described in `flymake-diagnostic-functions' (which
+see). Optional FORCE says to handle a report even if TOKEN was
+not expected."
+  (let* ((state (gethash backend flymake--backend-state))
+         (first-report (not (flymake--backend-state-reported-p state))))
+    (setf (flymake--backend-state-reported-p state) t)
+    (let (expected-token
+          new-diags)
+      (cond
+       ((null state)
+        (flymake-error
+         "Unexpected report from unknown backend %s" backend))
+       ((flymake--backend-state-disabled state)
+        (flymake-error
+         "Unexpected report from disabled backend %s" backend))
+       ((progn
+          (setq expected-token (flymake--backend-state-running state))
+          (null expected-token))
+        ;; should never happen
+        (flymake-error "Unexpected report from stopped backend %s" backend))
+       ((and (not (eq expected-token token))
+             (not force))
+        (flymake-error "Obsolete report from backend %s with explanation %s"
+                       backend explanation))
+       ((eq :panic report-action)
+        (flymake--disable-backend backend explanation))
+       ((not (listp report-action))
+        (flymake--disable-backend backend
+                                  (format "Unknown action %S" report-action))
+        (flymake-error "Expected report, but got unknown key %s" report-action))
+       (t
+        (setq new-diags report-action)
+        (save-restriction
+          (widen)
+          ;; only delete overlays if this is the first report
+          (when first-report
+            (flymake-delete-own-overlays
+             (lambda (ov)
+               (eq backend
+                   (flymake--diag-backend
+                    (overlay-get ov 'flymake--diagnostic))))))
+          (mapc (lambda (diag)
+                  (flymake--highlight-line diag)
+                  (setf (flymake--diag-backend diag) backend))
+                new-diags)
+          (setf (flymake--backend-state-diags state)
+                (append new-diags (flymake--backend-state-diags state)))
+          (when flymake-check-start-time
+            (flymake-log :debug "backend %s reported %d diagnostics in %.2f second(s)"
+                         backend
+                         (length new-diags)
+                         (- (float-time) flymake-check-start-time)))))))))
+
+(defun flymake-make-report-fn (backend &optional token)
+  "Make a suitable anonymous report function for BACKEND.
+BACKEND is used to help Flymake distinguish different diagnostic
+sources.  If provided, TOKEN helps Flymake distinguish between
+different runs of the same backend."
+  (let ((buffer (current-buffer)))
+    (lambda (&rest args)
+      (when (buffer-live-p buffer)
+        (with-current-buffer buffer
+          (apply #'flymake--handle-report backend token args))))))
+
+(defun flymake--collect (fn)
+  (let (retval)
+    (maphash (lambda (backend state)
+               (when (funcall fn state) (push backend retval)))
+             flymake--backend-state)
+    retval))
+
+(defun flymake-running-backends ()
+  "Compute running Flymake backends in current buffer."
+  (flymake--collect #'flymake--backend-state-running))
+
+(defun flymake-disabled-backends ()
+  "Compute disabled Flymake backends in current buffer."
+  (flymake--collect #'flymake--backend-state-disabled))
+
+(defun flymake-reporting-backends ()
+  "Compute reporting Flymake backends in current buffer."
+  (flymake--collect #'flymake--backend-state-reported-p))
+
+(defun flymake--disable-backend (backend &optional explanation)
+  "Disable BACKEND because EXPLANATION.
+If it is running also stop it."
+  (flymake-log :warning "Disabling backend %s because %s" backend explanation)
+  (flymake--with-backend-state backend state
+    (setf (flymake--backend-state-running state) nil
+          (flymake--backend-state-disabled state) explanation
+          (flymake--backend-state-reported-p state) t)))
+
+(defun flymake--run-backend (backend)
+  "Run the backend BACKEND, reenabling if necessary."
+  (flymake-log :debug "Running backend %s" backend)
+  (let ((run-token (cl-gensym "backend-token")))
+    (flymake--with-backend-state backend state
+      (setf (flymake--backend-state-running state) run-token
+            (flymake--backend-state-disabled state) nil
+            (flymake--backend-state-diags state) nil
+            (flymake--backend-state-reported-p state) nil))
+    ;; FIXME: Should use `condition-case-unless-debug' here, but don't
+    ;; for two reasons: (1) that won't let me catch errors from inside
+    ;; `ert-deftest' where `debug-on-error' appears to be always
+    ;; t. (2) In cases where the user is debugging elisp somewhere
+    ;; else, and using flymake, the presence of a frequently
+    ;; misbehaving backend in the global hook (most likely the legacy
+    ;; backend) will trigger an annoying backtrace.
+    ;;
+    (condition-case err
+        (funcall backend
+                 (flymake-make-report-fn backend run-token))
+      (error
+       (flymake--disable-backend backend err)))))
+
+(defun flymake-start (&optional deferred force)
+  "Start a syntax check.
+Start it immediately, or after current command if DEFERRED is
+non-nil.  With optional FORCE run even disabled backends.
+
+Interactively, with a prefix arg, FORCE is t."
+  (interactive (list nil current-prefix-arg))
+  (cl-labels
+      ((start
+        ()
+        (remove-hook 'post-command-hook #'start 'local)
+        (setq flymake-check-start-time (float-time))
+        (run-hook-wrapped
+         'flymake-diagnostic-functions
+         (lambda (backend)
+           (cond
+            ((and (not force)
+                  (flymake--with-backend-state backend state
+                    (flymake--backend-state-disabled state)))
+             (flymake-log :debug "Backend %s is disabled, not starting"
+                          backend))
+            (t
+             (flymake--run-backend backend)))
+           nil))))
+    (if (and deferred
+             this-command)
+        (add-hook 'post-command-hook #'start 'append 'local)
+      (start))))
+
+(defvar flymake-mode-map
+  (let ((map (make-sparse-keymap))) map)
+  "Keymap for `flymake-mode'")
+
+;;;###autoload
+(define-minor-mode flymake-mode nil
+  :group 'flymake :lighter flymake--mode-line-format :keymap flymake-mode-map
+  (cond
+   ;; Turning the mode ON.
+   (flymake-mode
+    (add-hook 'after-change-functions 'flymake-after-change-function nil t)
+    (add-hook 'after-save-hook 'flymake-after-save-hook nil t)
+    (add-hook 'kill-buffer-hook 'flymake-kill-buffer-hook nil t)
+
+    (setq flymake--backend-state (make-hash-table))
+
+    (when flymake-start-syntax-check-on-find-file
+      (flymake-start)))
+
+   ;; Turning the mode OFF.
+   (t
+    (remove-hook 'after-change-functions 'flymake-after-change-function t)
+    (remove-hook 'after-save-hook 'flymake-after-save-hook t)
+    (remove-hook 'kill-buffer-hook 'flymake-kill-buffer-hook t)
+    ;;+(remove-hook 'find-file-hook (function flymake-find-file-hook) t)
+
+    (flymake-delete-own-overlays)
+
+    (when flymake-timer
+      (cancel-timer flymake-timer)
+      (setq flymake-timer nil)))))
+
+(defun flymake--schedule-timer-maybe ()
+  "(Re)schedule an idle timer for checking the buffer.
+Do it only if `flymake-no-changes-timeout' is non-nil."
+  (when flymake-timer (cancel-timer flymake-timer))
+  (when flymake-no-changes-timeout
+    (setq
+     flymake-timer
+     (run-with-idle-timer
+      (seconds-to-time flymake-no-changes-timeout)
+      nil
+      (lambda (buffer)
+        (when (buffer-live-p buffer)
+          (with-current-buffer buffer
+            (when (and flymake-mode
+                       flymake-no-changes-timeout)
+	      (flymake-log
+               :debug "starting syntax check after idle for %s seconds"
+               flymake-no-changes-timeout)
+	      (flymake-start))
+            (setq flymake-timer nil))))
+      (current-buffer)))))
+
+;;;###autoload
+(defun flymake-mode-on ()
+  "Turn Flymake mode on."
+  (flymake-mode 1))
+
+;;;###autoload
+(defun flymake-mode-off ()
+  "Turn Flymake mode off."
+  (flymake-mode 0))
+
+(make-obsolete 'flymake-mode-on 'flymake-mode "26.1")
+(make-obsolete 'flymake-mode-off 'flymake-mode "26.1")
+
+(defun flymake-after-change-function (start stop _len)
+  "Start syntax check for current buffer if it isn't already running."
+  (let((new-text (buffer-substring start stop)))
+    (when (and flymake-start-syntax-check-on-newline (equal new-text "\n"))
+      (flymake-log :debug "starting syntax check as new-line has been seen")
+      (flymake-start 'deferred))
+    (flymake--schedule-timer-maybe)))
+
+(defun flymake-after-save-hook ()
+  (when flymake-mode
+    (flymake-log :debug "starting syntax check as buffer was saved")
+    (flymake-start)))
+
+(defun flymake-kill-buffer-hook ()
+  (when flymake-timer
+    (cancel-timer flymake-timer)
+    (setq flymake-timer nil)))
+
+(defun flymake-find-file-hook ()
+  (unless (or flymake-mode
+              (null flymake-diagnostic-functions))
+    (flymake-mode)
+    (flymake-log :warning "Turned on in `flymake-find-file-hook'")))
+
+(defun flymake-goto-next-error (&optional n filter interactive)
+  "Go to Nth next Flymake error in buffer matching FILTER.
+Interactively, always move to the next error.  With a prefix arg,
+skip any diagnostics with a severity less than ‘:warning’.
+
+If ‘flymake-wrap-around’ is non-nil and no more next errors,
+resumes search from top
+
+FILTER is a list of diagnostic types found in
+`flymake-diagnostic-types-alist', or nil, if no filter is to be
+applied."
+  ;; TODO: let filter be a number, a severity below which diags are
+  ;; skipped.
+  (interactive (list 1
+                     (if current-prefix-arg
+                         '(:error :warning))
+                     t))
+  (let* ((n (or n 1))
+         (ovs (flymake--overlays :filter
+                                 (lambda (ov)
+                                   (let ((diag (overlay-get
+                                                ov
+                                                'flymake--diagnostic)))
+                                     (and diag
+                                          (or (not filter)
+                                              (memq (flymake--diag-type diag)
+                                                    filter)))))
+                                 :compare (if (cl-plusp n) #'< #'>)
+                                 :key #'overlay-start))
+         (tail (cl-member-if (lambda (ov)
+                               (if (cl-plusp n)
+                                   (> (overlay-start ov)
+                                      (point))
+                                 (< (overlay-start ov)
+                                    (point))))
+                             ovs))
+         (chain (if flymake-wrap-around
+                    (if tail
+                        (progn (setcdr (last tail) ovs) tail)
+                      (and ovs (setcdr (last ovs) ovs)))
+                  tail))
+         (target (nth (1- n) chain)))
+    (cond (target
+           (goto-char (overlay-start target))
+           (when interactive
+             (message
+              (funcall (overlay-get target 'help-echo)
+                       nil nil (point)))))
+          (interactive
+           (user-error "No more Flymake errors%s"
+                       (if filter
+                           (format " of types %s" filter)
+                         ""))))))
+
+(defun flymake-goto-prev-error (&optional n filter interactive)
+  "Go to Nth previous Flymake error in buffer matching FILTER.
+Interactively, always move to the previous error.  With a prefix
+arg, skip any diagnostics with a severity less than ‘:warning’.
+
+If ‘flymake-wrap-around’ is non-nil and no more previous errors,
+resumes search from bottom.
+
+FILTER is a list of diagnostic types found in
+`flymake-diagnostic-types-alist', or nil, if no filter is to be
+applied."
+  (interactive (list 1 (if current-prefix-arg
+                           '(:error :warning))
+                     t))
+  (flymake-goto-next-error (- (or n 1)) filter interactive))
+
+
+;;; Mode-line and menu
+;;;
+(easy-menu-define flymake-menu flymake-mode-map "Flymake"
+  `("Flymake"
+    [ "Go to next error"      flymake-goto-next-error t ]
+    [ "Go to previous error"  flymake-goto-prev-error t ]
+    [ "Check now"             flymake-start t ]
+    [ "Go to log buffer"      flymake-switch-to-log-buffer t ]
+    "--"
+    [ "Turn off Flymake"      flymake-mode t ]))
+
+(defvar flymake--mode-line-format `(:eval (flymake--mode-line-format)))
+
+(put 'flymake--mode-line-format 'risky-local-variable t)
+
+(defun flymake--mode-line-format ()
+  "Produce a pretty minor mode indicator."
+  (let* ((known (hash-table-keys flymake--backend-state))
+         (running (flymake-running-backends))
+         (disabled (flymake-disabled-backends))
+         (reported (flymake-reporting-backends))
+         (diags-by-type (make-hash-table))
+         (all-disabled (and disabled (null running)))
+         (some-waiting (cl-set-difference running reported)))
+    (maphash (lambda (_b state)
+               (mapc (lambda (diag)
+                       (push diag
+                             (gethash (flymake--diag-type diag)
+                                      diags-by-type)))
+                     (flymake--backend-state-diags state)))
+             flymake--backend-state)
+    `((:propertize " Flymake"
+                   mouse-face mode-line-highlight
+                   help-echo
+                   ,(concat (format "%s known backends\n" (length known))
+                            (format "%s running\n" (length running))
+                            (format "%s disabled\n" (length disabled))
+                            "mouse-1: go to log buffer ")
+                   keymap
+                   ,(let ((map (make-sparse-keymap)))
+                      (define-key map [mode-line down-mouse-1]
+                        flymake-menu)
+                      map))
+      ,@(pcase-let ((`(,ind ,face ,explain)
+                     (cond ((null known)
+                            `("?" mode-line "No known backends"))
+                           (some-waiting
+                            `("Wait" compilation-mode-line-run
+                              ,(format "Waiting for %s running backend(s)"
+                                       (length some-waiting))))
+                           (all-disabled
+                            `("!" compilation-mode-line-run
+                              "All backends disabled"))
+                           (t
+                            `(nil nil nil)))))
+          (when ind
+            `((":"
+               (:propertize ,ind
+                            face ,face
+                            help-echo ,explain
+                            keymap
+                            ,(let ((map (make-sparse-keymap)))
+                               (define-key map [mode-line mouse-1]
+                                 'flymake-switch-to-log-buffer)
+                               map))))))
+      ,@(unless (or all-disabled
+                    (null known))
+          (cl-loop
+           for (type . severity)
+           in (cl-sort (mapcar (lambda (type)
+                                 (cons type (flymake--lookup-type-property
+                                             type
+                                             'severity
+                                             (warning-numeric-level :error))))
+                               (cl-union (hash-table-keys diags-by-type)
+                                         '(:error :warning)))
+                       #'>
+                       :key #'cdr)
+           for diags = (gethash type diags-by-type)
+           for face = (flymake--lookup-type-property type
+                                                     'mode-line-face
+                                                     'compilation-error)
+           when (or diags
+                    (>= severity (warning-numeric-level :warning)))
+           collect `(:propertize
+                     ,(format "%d" (length diags))
+                     face ,face
+                     mouse-face mode-line-highlight
+                     keymap
+                     ,(let ((map (make-sparse-keymap))
+                            (type type))
+                        (define-key map [mode-line mouse-4]
+                          (lambda (_event)
+                            (interactive "e")
+                            (flymake-goto-prev-error 1 (list type) t)))
+                        (define-key map [mode-line mouse-5]
+                          (lambda (_event)
+                            (interactive "e")
+                            (flymake-goto-next-error 1 (list type) t)))
+                        map)
+                     help-echo
+                     ,(concat (format "%s diagnostics of type %s\n"
+                                      (propertize (format "%d"
+                                                          (length diags))
+                                                  'face face)
+                                      (propertize (format "%s" type)
+                                                  'face face))
+                              "mouse-4/mouse-5: previous/next of this type\n"))
+           into forms
+           finally return
+           `((:propertize "[")
+             ,@(cl-loop for (a . rest) on forms by #'cdr
+                        collect a when rest collect
+                        '(:propertize " "))
+             (:propertize "]")))))))
 
 (provide 'flymake)
+
+(require 'flymake-proc)
+
 ;;; flymake.el ends here
diff --git a/lisp/progmodes/python.el b/lisp/progmodes/python.el
index 365191c56b0..9aa5134ca0d 100644
--- a/lisp/progmodes/python.el
+++ b/lisp/progmodes/python.el
@@ -3442,6 +3442,8 @@ def __PYTHON_EL_native_completion_setup():
                 instance.rlcomplete = new_completer
 
         if readline.__doc__ and 'libedit' in readline.__doc__:
+            raise Exception('''libedit based readline is known not to work,
+      see etc/PROBLEMS under \"In Inferior Python mode, input is echoed\".''')
             readline.parse_and_bind('bind ^I rl_complete')
         else:
             readline.parse_and_bind('tab: complete')
@@ -3450,7 +3452,9 @@ def __PYTHON_EL_native_completion_setup():
 
         print ('python.el: native completion setup loaded')
     except:
-        print ('python.el: native completion setup failed')
+        import sys
+        print ('python.el: native completion setup failed, %s: %s'
+               % sys.exc_info()[:2])
 
 __PYTHON_EL_native_completion_setup()" process)
       (when (and