* [PATCH v3] tools: detect appropriate debug optimization level
@ 2016-04-26 14:38 Doug Goldstein
2016-04-28 10:57 ` Wei Liu
` (2 more replies)
0 siblings, 3 replies; 9+ messages in thread
From: Doug Goldstein @ 2016-04-26 14:38 UTC (permalink / raw)
To: xen-devel; +Cc: Wei Liu, Ian Jackson, Doug Goldstein
When building debug use -Og as the optimization level if its available,
otherwise retain the use of -O0. -Og has been added by GCC to enable all
optimizations that to not affect debugging while retaining full
debugability.
Signed-off-by: Doug Goldstein <cardoe@cardoe.com>
---
change since v2:
- switch back to cc-option-add to not call cc-option on every invocation
change since v1:
- switch to cc-option to only specify -O0 if -Og isn't supported
---
tools/Rules.mk | 1 +
1 file changed, 1 insertion(+)
diff --git a/tools/Rules.mk b/tools/Rules.mk
index 9ef0b47..1b79a6e 100644
--- a/tools/Rules.mk
+++ b/tools/Rules.mk
@@ -138,6 +138,7 @@ SHLIB_libxenvchan = $(SHDEPS_libxenvchan) -Wl,-rpath-link=$(XEN_LIBVCHAN)
ifeq ($(debug),y)
# Disable optimizations and enable debugging information for macros
CFLAGS += -O0 -g3
+$(call cc-option-add,CFLAGS,CC,-Og)
# But allow an override to -O0 in case Python enforces -D_FORTIFY_SOURCE=<n>.
PY_CFLAGS += $(PY_NOOPT_CFLAGS)
endif
--
2.7.3
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel
^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH v3] tools: detect appropriate debug optimization level
2016-04-26 14:38 [PATCH v3] tools: detect appropriate debug optimization level Doug Goldstein
@ 2016-04-28 10:57 ` Wei Liu
2016-04-28 17:19 ` Ian Jackson
2016-04-28 17:40 ` Wei Liu
2 siblings, 0 replies; 9+ messages in thread
From: Wei Liu @ 2016-04-28 10:57 UTC (permalink / raw)
To: Doug Goldstein; +Cc: Wei Liu, Ian Jackson, xen-devel
On Tue, Apr 26, 2016 at 09:38:45AM -0500, Doug Goldstein wrote:
> When building debug use -Og as the optimization level if its available,
> otherwise retain the use of -O0. -Og has been added by GCC to enable all
> optimizations that to not affect debugging while retaining full
> debugability.
>
> Signed-off-by: Doug Goldstein <cardoe@cardoe.com>
I think Ian's comment has been addressed in this version:
Acked-by: Wei Liu <wei.liu2@citrix.com>
I plan to accept this patch for 4.7, the risk is rather low anyway.
I will wait a bit before committing in case Ian has more to say.
> ---
> change since v2:
> - switch back to cc-option-add to not call cc-option on every invocation
> change since v1:
> - switch to cc-option to only specify -O0 if -Og isn't supported
> ---
> tools/Rules.mk | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/tools/Rules.mk b/tools/Rules.mk
> index 9ef0b47..1b79a6e 100644
> --- a/tools/Rules.mk
> +++ b/tools/Rules.mk
> @@ -138,6 +138,7 @@ SHLIB_libxenvchan = $(SHDEPS_libxenvchan) -Wl,-rpath-link=$(XEN_LIBVCHAN)
> ifeq ($(debug),y)
> # Disable optimizations and enable debugging information for macros
> CFLAGS += -O0 -g3
> +$(call cc-option-add,CFLAGS,CC,-Og)
> # But allow an override to -O0 in case Python enforces -D_FORTIFY_SOURCE=<n>.
> PY_CFLAGS += $(PY_NOOPT_CFLAGS)
> endif
> --
> 2.7.3
>
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v3] tools: detect appropriate debug optimization level
2016-04-26 14:38 [PATCH v3] tools: detect appropriate debug optimization level Doug Goldstein
2016-04-28 10:57 ` Wei Liu
@ 2016-04-28 17:19 ` Ian Jackson
2016-04-28 17:22 ` Wei Liu
2016-04-28 17:40 ` Wei Liu
2 siblings, 1 reply; 9+ messages in thread
From: Ian Jackson @ 2016-04-28 17:19 UTC (permalink / raw)
To: Doug Goldstein; +Cc: Wei Liu, xen-devel
Doug Goldstein writes ("[PATCH v3] tools: detect appropriate debug optimization level"):
> When building debug use -Og as the optimization level if its available,
> otherwise retain the use of -O0. -Og has been added by GCC to enable all
> optimizations that to not affect debugging while retaining full
> debugability.
>
> Signed-off-by: Doug Goldstein <cardoe@cardoe.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v3] tools: detect appropriate debug optimization level
2016-04-28 17:19 ` Ian Jackson
@ 2016-04-28 17:22 ` Wei Liu
0 siblings, 0 replies; 9+ messages in thread
From: Wei Liu @ 2016-04-28 17:22 UTC (permalink / raw)
To: Ian Jackson; +Cc: Wei Liu, Doug Goldstein, xen-devel
On Thu, Apr 28, 2016 at 06:19:19PM +0100, Ian Jackson wrote:
> Doug Goldstein writes ("[PATCH v3] tools: detect appropriate debug optimization level"):
> > When building debug use -Og as the optimization level if its available,
> > otherwise retain the use of -O0. -Og has been added by GCC to enable all
> > optimizations that to not affect debugging while retaining full
> > debugability.
> >
> > Signed-off-by: Doug Goldstein <cardoe@cardoe.com>
>
> Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Queued.
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v3] tools: detect appropriate debug optimization level
2016-04-26 14:38 [PATCH v3] tools: detect appropriate debug optimization level Doug Goldstein
2016-04-28 10:57 ` Wei Liu
2016-04-28 17:19 ` Ian Jackson
@ 2016-04-28 17:40 ` Wei Liu
2018-02-24 5:26 ` Doug Goldstein
2 siblings, 1 reply; 9+ messages in thread
From: Wei Liu @ 2016-04-28 17:40 UTC (permalink / raw)
To: Doug Goldstein; +Cc: Wei Liu, Ian Jackson, xen-devel
On Tue, Apr 26, 2016 at 09:38:45AM -0500, Doug Goldstein wrote:
> When building debug use -Og as the optimization level if its available,
> otherwise retain the use of -O0. -Og has been added by GCC to enable all
> optimizations that to not affect debugging while retaining full
> debugability.
>
> Signed-off-by: Doug Goldstein <cardoe@cardoe.com>
> ---
> change since v2:
> - switch back to cc-option-add to not call cc-option on every invocation
> change since v1:
> - switch to cc-option to only specify -O0 if -Og isn't supported
> ---
> tools/Rules.mk | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/tools/Rules.mk b/tools/Rules.mk
> index 9ef0b47..1b79a6e 100644
> --- a/tools/Rules.mk
> +++ b/tools/Rules.mk
> @@ -138,6 +138,7 @@ SHLIB_libxenvchan = $(SHDEPS_libxenvchan) -Wl,-rpath-link=$(XEN_LIBVCHAN)
> ifeq ($(debug),y)
> # Disable optimizations and enable debugging information for macros
> CFLAGS += -O0 -g3
> +$(call cc-option-add,CFLAGS,CC,-Og)
> # But allow an override to -O0 in case Python enforces -D_FORTIFY_SOURCE=<n>.
> PY_CFLAGS += $(PY_NOOPT_CFLAGS)
> endif
> --
> 2.7.3
Heh, this patch seems to has a (good) side effect. I will look into
fixing that tomorrow.
make[10]: Entering directory '/local/work/COMMITTER/xen.git/tools/firmware/rombios/32bit/tcgbios'
gcc -O1 -fno-omit-frame-pointer -m32 -march=i686 -g -fno-strict-aliasing -std=gnu99 -Wall -Wstrict-prototypes -Wdeclaration-after-statement -Wno-unused-but-set-variable -Wno-unused-local-typedefs -O0 -g3 -Og -D__XEN_INTERFACE_VERSION__=__XEN_LATEST_INTERFACE_VERSION__ -MMD -MF .tcgbios.o.d -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -fno-optimize-sibling-calls -mno-tls-direct-seg-refs -Werror -fno-stack-protector -fno-exceptions -fno-builtin -msoft-float -I/local/work/COMMITTER/xen.git/tools/firmware/rombios/32bit/tcgbios/../../../../../tools/include -I.. -I../.. -c -o tcgbios.o tcgbios.c
gcc -O1 -fno-omit-frame-pointer -m32 -march=i686 -g -fno-strict-aliasing -std=gnu99 -Wall -Wstrict-prototypes -Wdeclaration-after-statement -Wno-unused-but-set-variable -Wno-unused-local-typedefs -O0 -g3 -Og -D__XEN_INTERFACE_VERSION__=__XEN_LATEST_INTERFACE_VERSION__ -MMD -MF .tpm_drivers.o.d -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -fno-optimize-sibling-calls -mno-tls-direct-seg-refs -Werror -fno-stack-protector -fno-exceptions -fno-builtin -msoft-float -I/local/work/COMMITTER/xen.git/tools/firmware/rombios/32bit/tcgbios/../../../../../tools/include -I.. -I../.. -c -o tpm_drivers.o tpm_drivers.c
tcgbios.c: In function ‘tcpa_extend_acpi_log’:
tcgbios.c:362:3: error: ‘size’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
memcpy((char *)lasa_last, (char *)entry_ptr, size);
^
tcgbios.c: In function ‘HashLogEvent32’:
tcgbios.c:1142:22: error: ‘entry’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
hleo->eventnumber = entry;
^
tcgbios.c:1131:10: error: ‘logdataptr’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
entry = tcpa_extend_acpi_log(logdataptr);
^
cc1: all warnings being treated as errors
/local/work/COMMITTER/xen.git/tools/firmware/rombios/32bit/tcgbios/../../../../../tools/Rules.mk:192: recipe for target 'tcgbios.o' failed
make[10]: *** [tcgbios.o] Error 1
make[10]: Leaving directory '/local/work/COMMITTER/xen.git/tools/firmware/rombios/32bit/tcgbios'
/local/work/COMMITTER/xen.git/tools/firmware/rombios/32bit/../../../../tools/Rules.mk:216: recipe for target 'subdir-all-tcgbios' failed
make[9]: *** [subdir-all-tcgbios] Error 2
make[9]: Leaving directory '/local/work/COMMITTER/xen.git/tools/firmware/rombios/32bit'
/local/work/COMMITTER/xen.git/tools/firmware/rombios/32bit/../../../../tools/Rules.mk:211: recipe for target 'subdirs-all' failed
make[8]: *** [subdirs-all] Error 2
make[8]: Leaving directory '/local/work/COMMITTER/xen.git/tools/firmware/rombios/32bit'
/local/work/COMMITTER/xen.git/tools/firmware/rombios/../../../tools/Rules.mk:216: recipe for target 'subdir-all-32bit' failed
make[7]: *** [subdir-all-32bit] Error 2
make[7]: Leaving directory '/local/work/COMMITTER/xen.git/tools/firmware/rombios'
/local/work/COMMITTER/xen.git/tools/firmware/rombios/../../../tools/Rules.mk:211: recipe for target 'subdirs-all' failed
make[6]: *** [subdirs-all] Error 2
make[6]: Leaving directory '/local/work/COMMITTER/xen.git/tools/firmware/rombios'
/local/work/COMMITTER/xen.git/tools/firmware/../../tools/Rules.mk:216: recipe for target 'subdir-all-rombios' failed
make[5]: *** [subdir-all-rombios] Error 2
make[5]: Leaving directory '/local/work/COMMITTER/xen.git/tools/firmware'
/local/work/COMMITTER/xen.git/tools/firmware/../../tools/Rules.mk:211: recipe for target 'subdirs-all' failed
make[4]: *** [subdirs-all] Error 2
make[4]: Leaving directory '/local/work/COMMITTER/xen.git/tools/firmware'
Makefile:33: recipe for target 'all' failed
make[3]: *** [all] Error 2
make[3]: Leaving directory '/local/work/COMMITTER/xen.git/tools/firmware'
/local/work/COMMITTER/xen.git/tools/../tools/Rules.mk:216: recipe for target 'subdir-install-firmware' failed
make[2]: *** [subdir-install-firmware] Error 2
make[2]: Leaving directory '/local/work/COMMITTER/xen.git/tools'
/local/work/COMMITTER/xen.git/tools/../tools/Rules.mk:211: recipe for target 'subdirs-install' failed
make[1]: *** [subdirs-install] Error 2
make[1]: Leaving directory '/local/work/COMMITTER/xen.git/tools'
Makefile:101: recipe for target 'install-tools' failed
make: *** [install-tools] Error 2
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v3] tools: detect appropriate debug optimization level
2016-04-28 17:40 ` Wei Liu
@ 2018-02-24 5:26 ` Doug Goldstein
2018-03-02 12:46 ` Wei Liu
0 siblings, 1 reply; 9+ messages in thread
From: Doug Goldstein @ 2018-02-24 5:26 UTC (permalink / raw)
To: Wei Liu; +Cc: Ian Jackson, xen-devel
[-- Attachment #1.1.1: Type: text/plain, Size: 3546 bytes --]
On 4/28/16 12:40 PM, Wei Liu wrote:
> On Tue, Apr 26, 2016 at 09:38:45AM -0500, Doug Goldstein wrote:
>> When building debug use -Og as the optimization level if its available,
>> otherwise retain the use of -O0. -Og has been added by GCC to enable all
>> optimizations that to not affect debugging while retaining full
>> debugability.
>>
>> Signed-off-by: Doug Goldstein <cardoe@cardoe.com>
>> ---
>> change since v2:
>> - switch back to cc-option-add to not call cc-option on every invocation
>> change since v1:
>> - switch to cc-option to only specify -O0 if -Og isn't supported
>> ---
>> tools/Rules.mk | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/tools/Rules.mk b/tools/Rules.mk
>> index 9ef0b47..1b79a6e 100644
>> --- a/tools/Rules.mk
>> +++ b/tools/Rules.mk
>> @@ -138,6 +138,7 @@ SHLIB_libxenvchan = $(SHDEPS_libxenvchan) -Wl,-rpath-link=$(XEN_LIBVCHAN)
>> ifeq ($(debug),y)
>> # Disable optimizations and enable debugging information for macros
>> CFLAGS += -O0 -g3
>> +$(call cc-option-add,CFLAGS,CC,-Og)
>> # But allow an override to -O0 in case Python enforces -D_FORTIFY_SOURCE=<n>.
>> PY_CFLAGS += $(PY_NOOPT_CFLAGS)
>> endif
>> --
>> 2.7.3
>
> Heh, this patch seems to has a (good) side effect. I will look into
> fixing that tomorrow.
>
> make[10]: Entering directory '/local/work/COMMITTER/xen.git/tools/firmware/rombios/32bit/tcgbios'
> gcc -O1 -fno-omit-frame-pointer -m32 -march=i686 -g -fno-strict-aliasing -std=gnu99 -Wall -Wstrict-prototypes -Wdeclaration-after-statement -Wno-unused-but-set-variable -Wno-unused-local-typedefs -O0 -g3 -Og -D__XEN_INTERFACE_VERSION__=__XEN_LATEST_INTERFACE_VERSION__ -MMD -MF .tcgbios.o.d -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -fno-optimize-sibling-calls -mno-tls-direct-seg-refs -Werror -fno-stack-protector -fno-exceptions -fno-builtin -msoft-float -I/local/work/COMMITTER/xen.git/tools/firmware/rombios/32bit/tcgbios/../../../../../tools/include -I.. -I../.. -c -o tcgbios.o tcgbios.c
> gcc -O1 -fno-omit-frame-pointer -m32 -march=i686 -g -fno-strict-aliasing -std=gnu99 -Wall -Wstrict-prototypes -Wdeclaration-after-statement -Wno-unused-but-set-variable -Wno-unused-local-typedefs -O0 -g3 -Og -D__XEN_INTERFACE_VERSION__=__XEN_LATEST_INTERFACE_VERSION__ -MMD -MF .tpm_drivers.o.d -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -fno-optimize-sibling-calls -mno-tls-direct-seg-refs -Werror -fno-stack-protector -fno-exceptions -fno-builtin -msoft-float -I/local/work/COMMITTER/xen.git/tools/firmware/rombios/32bit/tcgbios/../../../../../tools/include -I.. -I../.. -c -o tpm_drivers.o tpm_drivers.c
> tcgbios.c: In function ‘tcpa_extend_acpi_log’:
> tcgbios.c:362:3: error: ‘size’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
> memcpy((char *)lasa_last, (char *)entry_ptr, size);
> ^
> tcgbios.c: In function ‘HashLogEvent32’:
> tcgbios.c:1142:22: error: ‘entry’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
> hleo->eventnumber = entry;
> ^
> tcgbios.c:1131:10: error: ‘logdataptr’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
> entry = tcpa_extend_acpi_log(logdataptr);
> ^
This appears to be fixed with 0b5e769ae3ac81f8a8dfaf476147ccdf41caeb68
but the patch referenced here never landed. The patch doesn't apply
cleanly anymore (due to context) but its a one-liner so maybe someone
can fix it up as its committed?
--
Doug Goldstein
[-- Attachment #1.2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 963 bytes --]
[-- Attachment #2: Type: text/plain, Size: 157 bytes --]
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v3] tools: detect appropriate debug optimization level
2018-02-24 5:26 ` Doug Goldstein
@ 2018-03-02 12:46 ` Wei Liu
2018-03-11 5:08 ` Doug Goldstein
0 siblings, 1 reply; 9+ messages in thread
From: Wei Liu @ 2018-03-02 12:46 UTC (permalink / raw)
To: Doug Goldstein; +Cc: Ian Jackson, Wei Liu, xen-devel
On Fri, Feb 23, 2018 at 11:26:17PM -0600, Doug Goldstein wrote:
> On 4/28/16 12:40 PM, Wei Liu wrote:
> > On Tue, Apr 26, 2016 at 09:38:45AM -0500, Doug Goldstein wrote:
> >> When building debug use -Og as the optimization level if its available,
> >> otherwise retain the use of -O0. -Og has been added by GCC to enable all
> >> optimizations that to not affect debugging while retaining full
> >> debugability.
> >>
> >> Signed-off-by: Doug Goldstein <cardoe@cardoe.com>
> >> ---
> >> change since v2:
> >> - switch back to cc-option-add to not call cc-option on every invocation
> >> change since v1:
> >> - switch to cc-option to only specify -O0 if -Og isn't supported
> >> ---
> >> tools/Rules.mk | 1 +
> >> 1 file changed, 1 insertion(+)
> >>
> >> diff --git a/tools/Rules.mk b/tools/Rules.mk
> >> index 9ef0b47..1b79a6e 100644
> >> --- a/tools/Rules.mk
> >> +++ b/tools/Rules.mk
> >> @@ -138,6 +138,7 @@ SHLIB_libxenvchan = $(SHDEPS_libxenvchan) -Wl,-rpath-link=$(XEN_LIBVCHAN)
> >> ifeq ($(debug),y)
> >> # Disable optimizations and enable debugging information for macros
> >> CFLAGS += -O0 -g3
> >> +$(call cc-option-add,CFLAGS,CC,-Og)
Though -Og will supersede -O0 because it comes later, I would rather you
use cc-option to selectively add one of the two, like:
CFLAGS += $(cc-option,CC,-Og,-O0)
Wei.
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v3] tools: detect appropriate debug optimization level
2018-03-02 12:46 ` Wei Liu
@ 2018-03-11 5:08 ` Doug Goldstein
2018-03-12 16:16 ` Wei Liu
0 siblings, 1 reply; 9+ messages in thread
From: Doug Goldstein @ 2018-03-11 5:08 UTC (permalink / raw)
To: Wei Liu; +Cc: Ian Jackson, xen-devel
[-- Attachment #1.1.1: Type: text/plain, Size: 1622 bytes --]
On 3/2/18 6:46 AM, Wei Liu wrote:
> On Fri, Feb 23, 2018 at 11:26:17PM -0600, Doug Goldstein wrote:
>> On 4/28/16 12:40 PM, Wei Liu wrote:
>>> On Tue, Apr 26, 2016 at 09:38:45AM -0500, Doug Goldstein wrote:
>>>> When building debug use -Og as the optimization level if its available,
>>>> otherwise retain the use of -O0. -Og has been added by GCC to enable all
>>>> optimizations that to not affect debugging while retaining full
>>>> debugability.
>>>>
>>>> Signed-off-by: Doug Goldstein <cardoe@cardoe.com>
>>>> ---
>>>> change since v2:
>>>> - switch back to cc-option-add to not call cc-option on every invocation
>>>> change since v1:
>>>> - switch to cc-option to only specify -O0 if -Og isn't supported
>>>> ---
>>>> tools/Rules.mk | 1 +
>>>> 1 file changed, 1 insertion(+)
>>>>
>>>> diff --git a/tools/Rules.mk b/tools/Rules.mk
>>>> index 9ef0b47..1b79a6e 100644
>>>> --- a/tools/Rules.mk
>>>> +++ b/tools/Rules.mk
>>>> @@ -138,6 +138,7 @@ SHLIB_libxenvchan = $(SHDEPS_libxenvchan) -Wl,-rpath-link=$(XEN_LIBVCHAN)
>>>> ifeq ($(debug),y)
>>>> # Disable optimizations and enable debugging information for macros
>>>> CFLAGS += -O0 -g3
>>>> +$(call cc-option-add,CFLAGS,CC,-Og)
>
> Though -Og will supersede -O0 because it comes later, I would rather you
> use cc-option to selectively add one of the two, like:
>
> CFLAGS += $(cc-option,CC,-Og,-O0)
>
> Wei.
>
Wei,
It was like that in v2 but I changed it per Ian's request to this
version. See:
https://lists.xenproject.org/archives/html/xen-devel/2016-04/msg02822.html
for reference.
--
Doug Goldstein
[-- Attachment #1.2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 963 bytes --]
[-- Attachment #2: Type: text/plain, Size: 157 bytes --]
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v3] tools: detect appropriate debug optimization level
2018-03-11 5:08 ` Doug Goldstein
@ 2018-03-12 16:16 ` Wei Liu
0 siblings, 0 replies; 9+ messages in thread
From: Wei Liu @ 2018-03-12 16:16 UTC (permalink / raw)
To: Doug Goldstein; +Cc: Ian Jackson, Wei Liu, xen-devel
On Sat, Mar 10, 2018 at 11:08:21PM -0600, Doug Goldstein wrote:
> On 3/2/18 6:46 AM, Wei Liu wrote:
> > On Fri, Feb 23, 2018 at 11:26:17PM -0600, Doug Goldstein wrote:
> >> On 4/28/16 12:40 PM, Wei Liu wrote:
> >>> On Tue, Apr 26, 2016 at 09:38:45AM -0500, Doug Goldstein wrote:
> >>>> When building debug use -Og as the optimization level if its available,
> >>>> otherwise retain the use of -O0. -Og has been added by GCC to enable all
> >>>> optimizations that to not affect debugging while retaining full
> >>>> debugability.
> >>>>
> >>>> Signed-off-by: Doug Goldstein <cardoe@cardoe.com>
> >>>> ---
> >>>> change since v2:
> >>>> - switch back to cc-option-add to not call cc-option on every invocation
> >>>> change since v1:
> >>>> - switch to cc-option to only specify -O0 if -Og isn't supported
> >>>> ---
> >>>> tools/Rules.mk | 1 +
> >>>> 1 file changed, 1 insertion(+)
> >>>>
> >>>> diff --git a/tools/Rules.mk b/tools/Rules.mk
> >>>> index 9ef0b47..1b79a6e 100644
> >>>> --- a/tools/Rules.mk
> >>>> +++ b/tools/Rules.mk
> >>>> @@ -138,6 +138,7 @@ SHLIB_libxenvchan = $(SHDEPS_libxenvchan) -Wl,-rpath-link=$(XEN_LIBVCHAN)
> >>>> ifeq ($(debug),y)
> >>>> # Disable optimizations and enable debugging information for macros
> >>>> CFLAGS += -O0 -g3
> >>>> +$(call cc-option-add,CFLAGS,CC,-Og)
> >
> > Though -Og will supersede -O0 because it comes later, I would rather you
> > use cc-option to selectively add one of the two, like:
> >
> > CFLAGS += $(cc-option,CC,-Og,-O0)
> >
> > Wei.
> >
>
> Wei,
>
> It was like that in v2 but I changed it per Ian's request to this
> version. See:
> https://lists.xenproject.org/archives/html/xen-devel/2016-04/msg02822.html
> for reference.
That's a good point. We certainly want to avoid expanding the same thing
over and over again.
I think you can do with
ifneq ($(call cc-option,$(CC),-Og,n),n)
CFLAGS += -Og
else
CFLAGS += -O0
endif
Wei.
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2018-03-12 16:16 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-04-26 14:38 [PATCH v3] tools: detect appropriate debug optimization level Doug Goldstein
2016-04-28 10:57 ` Wei Liu
2016-04-28 17:19 ` Ian Jackson
2016-04-28 17:22 ` Wei Liu
2016-04-28 17:40 ` Wei Liu
2018-02-24 5:26 ` Doug Goldstein
2018-03-02 12:46 ` Wei Liu
2018-03-11 5:08 ` Doug Goldstein
2018-03-12 16:16 ` Wei Liu
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).