Re: [Qemu-devel] [PATCH] build: add needed missing libraries libm and librt

[Roger Pau Monné]

2012/2/18 Andreas Färber <address@hidden>:
> Am 18.02.2012 09:24, schrieb Blue Swirl:
>> On Wed, Feb 8, 2012 at 17:06, Roger Pau Monne <address@hidden> wrote:
>>> libm is used in cutils.c, but the library was not specified
>>> when linking some binaries, throwing the following error:
>>>
>>> cutils.o: In function `strtosz_suffix_unit':
>>> /home/royger/xen-clean/tools/qemu-xen-dir/cutils.c:354: undefined
>>> reference to `__isnan'
>>> /home/royger/xen-clean/tools/qemu-xen-dir/cutils.c:357: undefined
>>> reference to `modf'
>>> collect2: ld returned 1 exit status
>>>
>>> According to modf man page [0], -lm should be used when linking.
>>>
>>> librt is used in qemu-time.c, but again the library was not specified
>>> at link time, throwing the following error:
>>>
>>> /home/royger/xen-clean/tools/qemu-xen-dir/qemu-timer.c:597: undefined
>>> reference to `timer_gettime'
>>> /home/royger/xen-clean/tools/qemu-xen-dir/qemu-timer.c:610: undefined
>>> reference to `timer_settime'
>>> ../qemu-timer.o: In function `dynticks_start_timer':
>>> /home/royger/xen-clean/tools/qemu-xen-dir/qemu-timer.c:565: undefined
>>> reference to `timer_create'
>>> ../qemu-timer.o: In function `dynticks_stop_timer':
>>> /home/royger/xen-clean/tools/qemu-xen-dir/qemu-timer.c:583: undefined
>>> reference to `timer_delete'
>>> collect2: ld returned 1 exit status
>>>
>>> According to timer_getttime man page [1], -lrt should be used when
>>> linking.
>>>
>>> [0] http://linux.die.net/man/3/modf
>>> [1] http://linux.die.net/man/2/timer_gettime
>>
>> This is Linux man page, is this correct for all OS we support?
>
> No, not for Haiku or Mac OS X.
>
>> We already have a test for -lrt in configure, but it looks like it
>> does not detect your case correctly. You should fix that instead.

I've fixed the librt test in configure to work properly on my system,
that's uclibc 0.9.33.

>>
>>> Signed-off-by: Roger Pau Monne <address@hidden>
>>> ---
>>>  Makefile        |    4 ++--
>>>  Makefile.target |    2 ++
>>>  2 files changed, 4 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/Makefile b/Makefile
>>> index 301c75e..e2c3cd4 100644
>>> --- a/Makefile
>>> +++ b/Makefile
>>> @@ -34,7 +34,7 @@ configure: ;
>>>
>>>  $(call set-vpath, $(SRC_PATH):$(SRC_PATH)/hw)
>>>
>>> -LIBS+=-lz $(LIBS_TOOLS)
>>> +LIBS+=-lz -lm -lrt $(LIBS_TOOLS)
>
> NACK. You need to make sure it either lands in $(LIBS_TOOLS) or is added
> via a new variable with host-dependent contents.
>
>>>
>>>  ifdef BUILD_DOCS
>>>  DOCS=qemu-doc.html qemu-tech.html qemu.1 qemu-img.1 qemu-nbd.8 
>>> QMP/qmp-commands.txt
>>> @@ -170,7 +170,7 @@ test-coroutine: test-coroutine.o qemu-timer-common.o 
>>> async.o $(coroutine-obj-y)
>>>  $(qapi-obj-y): $(GENERATED_HEADERS)
>>>  qapi-dir := $(BUILD_DIR)/qapi-generated
>>>  test-visitor.o test-qmp-commands.o qemu-ga$(EXESUF): QEMU_CFLAGS += -I 
>>> $(qapi-dir)
>>> -qemu-ga$(EXESUF): LIBS = $(LIBS_QGA)
>>> +qemu-ga$(EXESUF): LIBS = $(LIBS_QGA) -lm
>
> NACK. Either needs to do LIBS += or must go in $(LIBS_QGA) or new
> conditionalized variable.
>
>>>
>>>  $(qapi-dir)/test-qapi-types.c $(qapi-dir)/test-qapi-types.h :\
>>>  $(SRC_PATH)/qapi-schema-test.json $(SRC_PATH)/scripts/qapi-types.py
>>> diff --git a/Makefile.target b/Makefile.target
>>> index a111521..95d6bc0 100644
>>> --- a/Makefile.target
>>> +++ b/Makefile.target
>>> @@ -33,6 +33,8 @@ endif
>>>  PROGS=$(QEMU_PROG)
>>>  STPFILES=
>>>
>>> +LIBS+=-lrt
>>> +
>
>>>  ifndef CONFIG_HAIKU
>>>  LIBS+=-lm
>>>  endif
>
> Here's the special treatment that avoids adding -lm on Haiku host
> because it doesn't have a libm.so (git-blame would've told you it's in
> libroot.so there); on Darwin there's a compatibility symlink but it's in
> libSystem.dylib actually and an ifndef would be appropriate as well.
> POSIX does not mandate -lm for math functions.
>
> Would moving this snippet to Makefile.objs help? What system are you on
> anyway and are you actually using upstream qemu.git? openSUSE 12.1 does
> not complain, and without a test case it's hard to find a solution here.

I've added a configure test to check for libm, just like the librt
test, so we no longer need the libm Haiuku conditional in the
Makefile, does that sound ok?

Regards, Roger.

>
> Andreas
>
>>> --
>>> 1.7.9
>
> --
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