bug#19466: 25.0.50; xref-find-def doesn't find C functions

[Dmitry Gutov]

On 01/31/2015 10:52 AM, Eli Zaretskii wrote:

> I tried that a few days ago, but didn't see any significant changes in
> behavior.  I'm probably missing something -- what exactly did you want
> me to pay attention to?

What have you tried, exactly?

You should have noticed that `M-.' in emacs-lisp-mode buffers behaves 
like in other buffers and uses the current tags table (and prompts for 
it if the tags table hasn't been visited yet).

I've found one caveat now: even though the tags list is not buffer-local 
(right?), (tags-lazy-completion-table) returns different results in 
lisp/**/*.el buffers and src/*.c buffers.

`find-tag' completion exhibits the same difference. For instance, 
calling `M-x find-tag' in src/disp.c, then typing `display_li' and 
pressing TAB will complete it to `display_line'. No so in 
lisp/progmodes/etags.el. Doing it in that buffer results in [No match]. 
However, typing `display_line' fully in either, then pressing RET, 
brings you to that function's definition. This should be considered a 
bug, right?

Until it is fixed, to be able to jump to `display_line' from lisp/** 
buffers, we have to disable the strict matching in 
`xref--read-identifier'. Please try #41 again with this patch applied:

diff --git a/lisp/progmodes/xref.el b/lisp/progmodes/xref.el
index 55405b6..f550282 100644
--- a/lisp/progmodes/xref.el
+++ b/lisp/progmodes/xref.el
@@ -562,7 +562,7 @@ Return an alist of the form ((FILENAME . (XREF ...)) 
...)."
     (cond ((or current-prefix-arg (not id))
            (completing-read prompt
                             (funcall 
xref-identifier-completion-table-function)
-                            nil t id
+                            nil nil id
                             'xref--read-identifier-history))
           (t id))))