On 07/24/2012 01:45 PM, Eric Blake wrote:
The quoted printf version ends up converting the literal leading space into '|', giving a regex (|VIR_ERROR|...) for $(func_re) which matches _everything_, when used with no further anchors. Thankfully, we were always using $(func_re) with a preceding anchor of \<, and the current glibc implementation of \< followed by an empty regex doesn't match (although I don't know if that was intentional).
I switched over to an unquoted printf, so as to let the shell do IFS splitting and thus eat the leading space.
Also, I didn't see right off why you've changed from using printf to using echo in the definition of func_or. Without looking at the definition of msg_gen_function, I suspect that switching to echo will add an unwanted trailing "|", no?
Oh, you're right; I swapped a leading empty regex for a trailing empty regex. '[[:space:]]' was too broad; checking for just space fixes it (since $(shell) eats trailing newlines, and tab was already converted to space by IFS splitting).
Seeing no ChangeLog entry, I wondered if it was an accident.
Intentional, but probably worth an independent commit since I had to justify it above.
Now pushed, as an independent commit: From fc32438fd4b71af6e643d0771a19b4a5c3679ed5 Mon Sep 17 00:00:00 2001 From: Eric Blake <eblake@redhat.com> Date: Thu, 26 Jul 2012 08:29:15 -0600 Subject: [PATCH] maint: avoid empty regex in syntax checker We were defining 'func_or' as '|VIR_ERROR|...', which when put inside 'func_re' resulted in a regex that matches everything in isolation. Thankfully, we always used func_re with a leading anchor \<, and since the empty regex does not start a word, we happened to get the result we wanted; but it's better to define func_or without a leading space converted into a leading empty alternation. * cfg.mk (func_or): Strip leading space. --- cfg.mk | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/cfg.mk b/cfg.mk index 0bf909d..882b2be 100644 --- a/cfg.mk +++ b/cfg.mk @@ -547,7 +547,7 @@ msg_gen_function += xenapiSessionErrorHandler # msg_gen_function += vshPrint # msg_gen_function += vshError -func_or := $(shell printf '$(msg_gen_function)'|tr -s '[[:space:]]' '|') +func_or := $(shell echo $(msg_gen_function)|tr -s ' ' '|') func_re := ($(func_or)) # Look for diagnostics that aren't marked for translation. -- 1.7.11.2 -- Eric Blake eblake@redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org