Mbed TLS indentation style for C

Signed-off-by: Gilles Peskine <[email protected]>

Author: gilles-peskine-arm

tools/emacs/mbedtls-autoloads.el

@@ -15,6 +15,54 @@
 ;; .function files are C code
 (add-to-list 'auto-mode-alist '("/suites/[^/]+\\.function\\'" . c-mode))
 
+;; Mbed TLS indentation style
+
+(defun cc-style-lineup-if-with-else (context)
+  "When there is a newline in else/if, indent if like else.
+That is, indent like this:
+    if (...)
+        ...
+    else
+    if (...)
+        ...
+instead of this:
+    if (...)
+        ...
+    else
+        if (...)
+            ...
+To achieve this, add `(substatement cc-style-lineup-if-with-else +)'
+to `c-offsets-alist'."
+  ;; https://emacs.stackexchange.com/questions/31038/stop-reindenting-if-after-else/31041#31041
+  (pcase context
+    (`(substatement . ,anchor)
+     (save-excursion
+       (back-to-indentation)
+       (when (looking-at-p "if\\_>")
+         (goto-char anchor)
+         (when (looking-at-p "\\(else\\|switch\\)\\_>")
+           0))))))
+
+(defun cc-style-make-mbedtls ()
+  (let ((entry (assoc "mbedtls" c-style-alist)))
+    (unless entry
+      (setq entry (cons "mbedtls" nil))
+      (setq c-style-alist (cons entry c-style-alist)))
+    (setcdr entry '((c-basic-offset . 4)
+                    (c-hanging-braces-alist
+                     (arglist-cont before after)
+                     (arglist-cont-nonempty before after)
+                     (substatement-open before after))
+                    (c-offsets-alist
+                     (case-label . +)
+                     (inextern-lang . 0)
+                     (label . 0)
+                     (substatement cc-style-lineup-if-with-else +)
+                     (substatement-open . 0)
+                     (substatement-label . 0)
+                     )))))
+(eval-after-load "cc-styles" '(cc-style-make-mbedtls))
+
 (provide 'mbedtls-autoloads)
 
 ;;; That's all.