Emacs make-mode doesn't know that ?= is a valid macro assignment operator,
so it doesn't know how to fontify it. I'll attach a patch.
Grr. Bugzilla is busted right now and won't let me attach the patch as a
separate file. Here it is:
--- /usr/share/emacs/20.7/lisp/progmodes/make-mode.el Sat Feb 6 23:01:34 1999
+++ /tmp/make-mode.el Wed Jul 25 14:12:16 2001
@@ -241,7 +241,7 @@
;; that if you change this regexp you might have to fix the imenu
;; index in makefile-imenu-generic-expression.
- "^ *\\([^ \n\t][^:#= \t\n]*\\)[ \t]*[*:+]?:?="
+ "^ *\\([^ \n\t][^:#= \t\n]*\\)[ \t]*[*:+]?[:?]?="
"Regex used to find macro assignment lines in a makefile.")
Will add. Bugs with patches are my preferred kind :)
Do you have any example makefiles using this?
FOO1 = bar
FOO2 := bar
FOO3 ?= bar
The first two lines will be colorized correctly without my fix. The third one
Fixed in emacs 20.7-41