# [PATCH v2] sparse: allow '{ 0 }' to be used without warnings 4 messages from 2020-05-22 to 2020-05-31. Participants: Luc Van Oostenryck, Junio C Hamano. Thread: https://gitlist.dev/t/53532 ## Luc Van Oostenryck, 2020-05-22 00:25 Subject: [PATCH v2] sparse: allow '{ 0 }' to be used without warnings Message-ID: <20200522002502.9010-1-luc.vanoostenryck@gmail.com> URL: https://gitlist.dev/e/20200522002502.9010-1-luc.vanoostenryck%40gmail.com ``` In standard C, '{ 0 }' can be used as an universal zero-initializer. However, Sparse complains if this is used on a type where the first member (possibly nested) is a pointer since Sparse purposely wants to warn when '0' is used to initialize a pointer type. Legitimaly, it's desirable to be able to use '{ 0 }' as an idiom without these warnings [1,2]. To allow this, an option have now been added to Sparse: 537e3e2dae univ-init: conditionally accept { 0 } without warnings So, add this option to the SPARSE_FLAGS variable. Note: The option have just been added to Sparse. So, to benefit now from this patch it's needed to use the latest Sparse source from kernel.org. The option will simply be ignored by older versions of Sparse. [1] https://lore.kernel.org/r/e6796c60-a870-e761-3b07-b680f934c537@ramsayjones.plus.com [2] https://lore.kernel.org/r/xmqqd07xem9l.fsf@gitster.c.googlers.com Signed-off-by: Luc Van Oostenryck --- Change since v1: * adapt the commit message to: - fix a typo - give a reference to the Spatch patch - add a note telling the latest Sparse source is needed to benefit from the patch but older versions won't complain. Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Makefile b/Makefile index 3d3a39fc19..69f065ef8c 100644 --- a/Makefile +++ b/Makefile @@ -1189,7 +1189,7 @@ PTHREAD_CFLAGS = # For the 'sparse' target SPARSE_FLAGS ?= -SP_EXTRA_FLAGS = +SP_EXTRA_FLAGS = -Wno-universal-initializer # For the 'coccicheck' target; setting SPATCH_BATCH_SIZE higher will # usually result in less CPU usage at the cost of higher peak memory. -- 2.26.2 ``` ## Junio C Hamano, 2020-05-24 16:17 Subject: Re: [PATCH v2] sparse: allow '{ 0 }' to be used without warnings Message-ID: URL: https://gitlist.dev/e/xmqqa71xqpd2.fsf%40gitster.c.googlers.com In-Reply-To: <20200522002502.9010-1-luc.vanoostenryck@gmail.com> ``` Luc Van Oostenryck writes: > Note: The option have just been added to Sparse. So, to benefit > now from this patch it's needed to use the latest Sparse > source from kernel.org. The option will simply be ignored > by older versions of Sparse. The last sentence in this paragraph is very very much appreciated ;-) > > [1] https://lore.kernel.org/r/e6796c60-a870-e761-3b07-b680f934c537@ramsayjones.plus.com > [2] https://lore.kernel.org/r/xmqqd07xem9l.fsf@gitster.c.googlers.com > > Signed-off-by: Luc Van Oostenryck > --- > > Change since v1: > * adapt the commit message to: > - fix a typo > - give a reference to the Spatch patch > - add a note telling the latest Sparse source is needed to > benefit from the patch but older versions won't complain. > > Makefile | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/Makefile b/Makefile > index 3d3a39fc19..69f065ef8c 100644 > --- a/Makefile > +++ b/Makefile > @@ -1189,7 +1189,7 @@ PTHREAD_CFLAGS = > > # For the 'sparse' target > SPARSE_FLAGS ?= > -SP_EXTRA_FLAGS = > +SP_EXTRA_FLAGS = -Wno-universal-initializer > > # For the 'coccicheck' target; setting SPATCH_BATCH_SIZE higher will > # usually result in less CPU usage at the cost of higher peak memory. ``` ## Luc Van Oostenryck, 2020-05-30 16:24 Subject: Re: [PATCH v2] sparse: allow '{ 0 }' to be used without warnings Message-ID: <20200530162432.a7fitzjc53hsn2ej@ltop.local> URL: https://gitlist.dev/e/20200530162432.a7fitzjc53hsn2ej%40ltop.local In-Reply-To: ``` Hi Junio, I've now changed Sparse's default to not warn when using '{ 0 }'. This flag is thus now unneeded for Git and can be dropped (but it won't hurt to keep it). -- Luc ``` ## Junio C Hamano, 2020-05-31 16:48 Subject: Re: [PATCH v2] sparse: allow '{ 0 }' to be used without warnings Message-ID: URL: https://gitlist.dev/e/xmqqh7vwvymv.fsf%40gitster.c.googlers.com In-Reply-To: <20200530162432.a7fitzjc53hsn2ej@ltop.local> ``` Luc Van Oostenryck writes: > I've now changed Sparse's default to not warn when using '{ 0 }'. > This flag is thus now unneeded for Git and can be dropped > (but it won't hurt to keep it). Nice. Thanks. ```