kern/118121: RELENG_7 kernel compile fails with -Os

[Heikki Suonsivu]

>Number:         118121
>Category:       kern
>Synopsis:       RELENG_7 kernel compile fails with -Os
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon Nov 19 11:50:02 UTC 2007
>Closed-Date:
>Last-Modified:
>Originator:     Heikki Suonsivu
>Release:        FreeBSD 7.0-BETA3 i386
>Organization:
bbnetworks.net
>Environment:
System: FreeBSD joutseno.wlansystems.com 7.0-BETA3 FreeBSD 7.0-BETA3 #3: Sun Nov 18 02:20:02 EET 2007 hsu at joutseno.wlansystems.com:/usr/obj/usr/src/sys/GENERIC i386

	Anything with RELENG_7, if compiling GENERIC with -Os

>Description:

	When compiling kernel with -Os, gcc apparently finds some new
	possible warnings (possible uninitialized variables, etc).  This exits
	kernel compile.  -O2 does not trigger these.

	scsi_sa and scsi_ses were among the offending files, but there
	may be more.

>How-To-Repeat:

	build kernel with COPTFLAGS set to -Os -g -pipe

>Fix:

	The offending code may need further checks.  RELENG_6 did not
	have these warnings, so they apparently are related to new
	code in 7.x.

	Workaround is to use -O2 or -O

>Release-Note:
>Audit-Trail:
>Unformatted: