Re: [Xen-devel] [PATCH v2 1/5] Remove hardcoded strict -Werror checking

[Alistair Francis <alistair.francis@xxxxxxxxxx>]

On Tue, Dec 20, 2016 at 12:16 PM, Andrew Cooper
<andrew.cooper3@xxxxxxxxxx> wrote:
> On 20/12/2016 20:06, Doug Goldstein wrote:
>> On 12/20/16 1:46 PM, Alistair Francis wrote:
>>> Signed-off-by: Alistair Francis <alistair.francis@xxxxxxxxxx>
>>> ---
>>>  Config.mk                      | 2 +-
>>>  tools/blktap2/drivers/Makefile | 1 -
>>>  tools/libxl/Makefile           | 2 +-
>>>  tools/xentrace/Makefile        | 2 --
>>>  4 files changed, 2 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/Config.mk b/Config.mk
>>> index 3ec7367..e3cda81 100644
>>> --- a/Config.mk
>>> +++ b/Config.mk
>>> @@ -34,7 +34,7 @@ CONFIG_$(XEN_OS) := y
>>>  SHELL     ?= /bin/sh
>>>
>>>  # Tools to run on system hosting the build
>>> -HOSTCFLAGS  = -Wall -Werror -Wstrict-prototypes -O2 -fomit-frame-pointer
>>> +HOSTCFLAGS  = -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer
>>>  HOSTCFLAGS += -fno-strict-aliasing
>>>
>>>  DISTDIR     ?= $(XEN_ROOT)/dist
>>> diff --git a/tools/blktap2/drivers/Makefile b/tools/blktap2/drivers/Makefile
>>> index 5328c40..7a62a3f 100644
>>> --- a/tools/blktap2/drivers/Makefile
>>> +++ b/tools/blktap2/drivers/Makefile
>>> @@ -9,7 +9,6 @@ QCOW_UTIL  = img2qcow qcow-create qcow2raw
>>>  LOCK_UTIL  = lock-util
>>>  INST_DIR   = $(sbindir)
>>>
>>> -CFLAGS    += -Werror
>>>  CFLAGS    += -Wno-unused
>>>  CFLAGS    += -fno-strict-aliasing
>>>  CFLAGS    += -I$(BLKTAP_ROOT)/include -I$(BLKTAP_ROOT)/drivers
>>> diff --git a/tools/libxl/Makefile b/tools/libxl/Makefile
>>> index 91e2f97..e8a37ef 100644
>>> --- a/tools/libxl/Makefile
>>> +++ b/tools/libxl/Makefile
>>> @@ -11,7 +11,7 @@ MINOR = 0
>>>  XLUMAJOR = 4.9
>>>  XLUMINOR = 0
>>>
>>> -CFLAGS += -Werror -Wno-format-zero-length -Wmissing-declarations \
>>> +CFLAGS += -Wno-format-zero-length -Wmissing-declarations \
>>>      -Wno-declaration-after-statement -Wformat-nonliteral
>>>  CFLAGS += -I. -fPIC
>>>
>>> diff --git a/tools/xentrace/Makefile b/tools/xentrace/Makefile
>>> index c8c36a8..ac5c534 100644
>>> --- a/tools/xentrace/Makefile
>>> +++ b/tools/xentrace/Makefile
>>> @@ -1,8 +1,6 @@
>>>  XEN_ROOT=$(CURDIR)/../..
>>>  include $(XEN_ROOT)/tools/Rules.mk
>>>
>>> -CFLAGS += -Werror
>>> -
>>>  CFLAGS += $(CFLAGS_libxenevtchn)
>>>  CFLAGS += $(CFLAGS_libxenctrl)
>>>  LDLIBS += $(LDLIBS_libxenevtchn)
>>>
>> Can you pass -Wno-error in EXTRA_CFLAGS from 2/5? Wish I could take
>> credit for the idea but it was all Andrew Cooper's.

I tried that, I still see errors when building lower levels like tools/xentrace.

>
> The point is that, especially with kernel-level development, almost all
> warnings are relevant to correctness.  I have only seen 2? false
> positives in 5 years, and have lost count of how many issues -Werror has
> caught before the code actually got committed.

I agree, but the problem is that as warnings change these cause all
sorts of build issues.

Thanks,

Alistair

>
> ~Andrew
>

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel