[{"id":2047,"web_url":"https://patchwork.libcamera.org/comment/2047/","msgid":"<20190628060748.sglsalponiqdagw5@uno.localdomain>","date":"2019-06-28T06:07:48","subject":"Re: [libcamera-devel] [PATCH] libcamera: v4l2_device: Fix\n\tvariable-sized object initialization","submitter":{"id":3,"url":"https://patchwork.libcamera.org/api/people/3/","name":"Jacopo Mondi","email":"jacopo@jmondi.org"},"content":"Hi Niklas,\n sorry, I didn't test on clang. It should become a standard practice\nsince it's the default compiler used for building, ie, Cros..\n\nOn Wed, Jun 26, 2019 at 07:35:43PM +0200, Nklas Söderlund wrote:\n> Compiling with clang renders errors as a variable-sized arrays are not\n> allowed to be initialized, solve this by using memset() instead.\n>\n> ../../src/libcamera/v4l2_device.cpp:155:37: error: variable-sized object may not be initialized\n> const V4L2ControlInfo *controlInfo[count] = {};\n> ^~~~~\n> ../../src/libcamera/v4l2_device.cpp:156:36: error: variable-sized object may not be initialized\n> \t struct v4l2_ext_control v4l2Ctrls[count] = {};\n> \t\t\t\t\t ^~~~~\n> ../../src/libcamera/v4l2_device.cpp:227:37: error: variable-sized object may not be initialized\n> \t const V4L2ControlInfo *controlInfo[count] = {};\n> \t\t\t\t\t ^~~~~\n> ../../src/libcamera/v4l2_device.cpp:228:36: error: variable-sized object may not be initialized\n> \t struct v4l2_ext_control v4l2Ctrls[count] = {};\n> \t\t\t\t\t ^~~~~\n> Fixes: eb068f4e67eedacd (\"libcamera: v4l2_device: Implement get and set controls\")\n> Signed-off-by: Niklas Söderlund \n> ---\n> src/libcamera/v4l2_device.cpp | 13 +++++++++----\n> 1 file changed, 9 insertions(+), 4 deletions(-)\n>\n> diff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp\n> index 84758a811c271976..d730df78e1ab2478 100644\n> --- a/src/libcamera/v4l2_device.cpp\n> +++ b/src/libcamera/v4l2_device.cpp\n> @@ -152,8 +152,11 @@ int V4L2Device::getControls(V4L2ControlList *ctrls)\n> \tif (count == 0)\n> \t\treturn 0;\n>\n> -\tconst V4L2ControlInfo *controlInfo[count] = {};\n> -\tstruct v4l2_ext_control v4l2Ctrls[count] = {};\n> +\tconst V4L2ControlInfo *controlInfo[count];\n\nNo need to zero this one.\n\n> +\tstruct v4l2_ext_control v4l2Ctrls[count];\n\nWe can initialize each entry as we walk them maybe?\n\n--- a/src/libcamera/v4l2_device.cpp\n+++ b/src/libcamera/v4l2_device.cpp\n@@ -152,8 +152,8 @@ int V4L2Device::getControls(V4L2ControlList *ctrls)\n if (count == 0)\n return 0;\n\n- const V4L2ControlInfo *controlInfo[count] = {};\n- struct v4l2_ext_control v4l2Ctrls[count] = {};\n+ const V4L2ControlInfo *controlInfo[count];\n+ struct v4l2_ext_control v4l2Ctrls[count];\n for (unsigned int i = 0; i < count; ++i) {\n const V4L2Control *ctrl = ctrls->getByIndex(i);\n const V4L2ControlInfo *info = getControlInfo(ctrl->id());\n@@ -164,6 +164,7 @@ int V4L2Device::getControls(V4L2ControlList *ctrls)\n }\n\n controlInfo[i] = info;\n+ v4l2Ctrls[i] = {};\n v4l2Ctrls[i].id = info->id();\n }\nWith the same to be done for setControl()?\n\nWhat do you think?\n\n> +\tmemset(controlInfo, 0, count * sizeof(controlInfo[0]));\n> +\tmemset(v4l2Ctrls, 0, count * sizeof(v4l2Ctrls[0]));\n> +\n> \tfor (unsigned int i = 0; i < count; ++i) {\n> \t\tconst V4L2Control *ctrl = ctrls->getByIndex(i);\n> \t\tconst V4L2ControlInfo *info = getControlInfo(ctrl->id());\n> @@ -224,8 +227,10 @@ int V4L2Device::setControls(V4L2ControlList *ctrls)\n> \tif (count == 0)\n> \t\treturn 0;\n>\n> -\tconst V4L2ControlInfo *controlInfo[count] = {};\n> -\tstruct v4l2_ext_control v4l2Ctrls[count] = {};\n> +\tconst V4L2ControlInfo *controlInfo[count];\n> +\tstruct v4l2_ext_control v4l2Ctrls[count];\n> +\tmemset(controlInfo, 0, count * sizeof(controlInfo[0]));\n> +\tmemset(v4l2Ctrls, 0, count * sizeof(v4l2Ctrls[0]));\n>\n> \tfor (unsigned int i = 0; i < count; ++i) {\n> \t\tconst V4L2Control *ctrl = ctrls->getByIndex(i);\n> --\n> 2.22.0\n>\n> _______________________________________________\n> libcamera-devel mailing list\n> libcamera-devel@lists.libcamera.org\n> https://lists.libcamera.org/listinfo/libcamera-devel","headers":{"Return-Path":"","Received":["from relay2-d.mail.gandi.net (relay2-d.mail.gandi.net\n\t[217.70.183.194])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 26BAD6157D\n\tfor ;\n\tFri, 28 Jun 2019 08:06:34 +0200 (CEST)","from uno.localdomain\n\t(host248-134-dynamic.46-79-r.retail.telecomitalia.it [79.46.134.248])\n\t(Authenticated sender: jacopo@jmondi.org)\n\tby relay2-d.mail.gandi.net (Postfix) with ESMTPSA id 6B48A40008;\n\tFri, 28 Jun 2019 06:06:33 +0000 (UTC)"],"X-Originating-IP":"79.46.134.248","Date":"Fri, 28 Jun 2019 08:07:48 +0200","From":"Jacopo Mondi ","To":"Niklas =?utf-8?q?S=C3=B6derlund?= ","Cc":"libcamera-devel@lists.libcamera.org","Message-ID":"<20190628060748.sglsalponiqdagw5@uno.localdomain>","References":"<20190626173543.2257-1-niklas.soderlund@ragnatech.se>","MIME-Version":"1.0","Content-Type":"multipart/signed; micalg=pgp-sha256;\n\tprotocol=\"application/pgp-signature\"; boundary=\"cze6xidu4wnats6f\"","Content-Disposition":"inline","In-Reply-To":"<20190626173543.2257-1-niklas.soderlund@ragnatech.se>","User-Agent":"NeoMutt/20180716","Subject":"Re: [libcamera-devel] [PATCH] libcamera: v4l2_device: Fix\n\tvariable-sized object initialization","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.23","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","X-List-Received-Date":"Fri, 28 Jun 2019 06:06:34 -0000"}},{"id":2053,"web_url":"https://patchwork.libcamera.org/comment/2053/","msgid":"<20190628123452.GF4779@pendragon.ideasonboard.com>","date":"2019-06-28T12:34:52","subject":"Re: [libcamera-devel] [PATCH] libcamera: v4l2_device: Fix\n\tvariable-sized object initialization","submitter":{"id":2,"url":"https://patchwork.libcamera.org/api/people/2/","name":"Laurent Pinchart","email":"laurent.pinchart@ideasonboard.com"},"content":"Hi Jacopo,\n\nOn Fri, Jun 28, 2019 at 08:07:48AM +0200, Jacopo Mondi wrote:\n> Hi Niklas,\n> sorry, I didn't test on clang. It should become a standard practice\n> since it's the default compiler used for building, ie, Cros..\n> \n> On Wed, Jun 26, 2019 at 07:35:43PM +0200, Nklas Söderlund wrote:\n> > Compiling with clang renders errors as a variable-sized arrays are not\n> > allowed to be initialized, solve this by using memset() instead.\n> >\n> > ../../src/libcamera/v4l2_device.cpp:155:37: error: variable-sized object may not be initialized\n> > const V4L2ControlInfo *controlInfo[count] = {};\n> > ^~~~~\n> > ../../src/libcamera/v4l2_device.cpp:156:36: error: variable-sized object may not be initialized\n> > \t struct v4l2_ext_control v4l2Ctrls[count] = {};\n> > \t\t\t\t\t ^~~~~\n> > ../../src/libcamera/v4l2_device.cpp:227:37: error: variable-sized object may not be initialized\n> > \t const V4L2ControlInfo *controlInfo[count] = {};\n> > \t\t\t\t\t ^~~~~\n> > ../../src/libcamera/v4l2_device.cpp:228:36: error: variable-sized object may not be initialized\n> > \t struct v4l2_ext_control v4l2Ctrls[count] = {};\n> > \t\t\t\t\t ^~~~~\n> > Fixes: eb068f4e67eedacd (\"libcamera: v4l2_device: Implement get and set controls\")\n> > Signed-off-by: Niklas Söderlund \n> > ---\n> > src/libcamera/v4l2_device.cpp | 13 +++++++++----\n> > 1 file changed, 9 insertions(+), 4 deletions(-)\n> >\n> > diff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp\n> > index 84758a811c271976..d730df78e1ab2478 100644\n> > --- a/src/libcamera/v4l2_device.cpp\n> > +++ b/src/libcamera/v4l2_device.cpp\n> > @@ -152,8 +152,11 @@ int V4L2Device::getControls(V4L2ControlList *ctrls)\n> > \tif (count == 0)\n> > \t\treturn 0;\n> >\n> > -\tconst V4L2ControlInfo *controlInfo[count] = {};\n> > -\tstruct v4l2_ext_control v4l2Ctrls[count] = {};\n> > +\tconst V4L2ControlInfo *controlInfo[count];\n> \n> No need to zero this one.\n> \n> > +\tstruct v4l2_ext_control v4l2Ctrls[count];\n> \n> We can initialize each entry as we walk them maybe?\n> \n> --- a/src/libcamera/v4l2_device.cpp\n> +++ b/src/libcamera/v4l2_device.cpp\n> @@ -152,8 +152,8 @@ int V4L2Device::getControls(V4L2ControlList *ctrls)\n> if (count == 0)\n> return 0;\n> \n> - const V4L2ControlInfo *controlInfo[count] = {};\n> - struct v4l2_ext_control v4l2Ctrls[count] = {};\n> + const V4L2ControlInfo *controlInfo[count];\n> + struct v4l2_ext_control v4l2Ctrls[count];\n> for (unsigned int i = 0; i < count; ++i) {\n> const V4L2Control *ctrl = ctrls->getByIndex(i);\n> const V4L2ControlInfo *info = getControlInfo(ctrl->id());\n> @@ -164,6 +164,7 @@ int V4L2Device::getControls(V4L2ControlList *ctrls)\n> }\n> \n> controlInfo[i] = info;\n> + v4l2Ctrls[i] = {};\n> v4l2Ctrls[i].id = info->id();\n> }\n> With the same to be done for setControl()?\n> \n> What do you think?\n\nWouldn't a single memset be more efficient ?\n\n> > +\tmemset(controlInfo, 0, count * sizeof(controlInfo[0]));\n> > +\tmemset(v4l2Ctrls, 0, count * sizeof(v4l2Ctrls[0]));\n> > +\n> > \tfor (unsigned int i = 0; i < count; ++i) {\n> > \t\tconst V4L2Control *ctrl = ctrls->getByIndex(i);\n> > \t\tconst V4L2ControlInfo *info = getControlInfo(ctrl->id());\n> > @@ -224,8 +227,10 @@ int V4L2Device::setControls(V4L2ControlList *ctrls)\n> > \tif (count == 0)\n> > \t\treturn 0;\n> >\n> > -\tconst V4L2ControlInfo *controlInfo[count] = {};\n> > -\tstruct v4l2_ext_control v4l2Ctrls[count] = {};\n> > +\tconst V4L2ControlInfo *controlInfo[count];\n> > +\tstruct v4l2_ext_control v4l2Ctrls[count];\n> > +\tmemset(controlInfo, 0, count * sizeof(controlInfo[0]));\n> > +\tmemset(v4l2Ctrls, 0, count * sizeof(v4l2Ctrls[0]));\n> >\n> > \tfor (unsigned int i = 0; i < count; ++i) {\n> > \t\tconst V4L2Control *ctrl = ctrls->getByIndex(i);","headers":{"Return-Path":"","Received":["from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 14FC460BC7\n\tfor ;\n\tFri, 28 Jun 2019 14:35:11 +0200 (CEST)","from pendragon.ideasonboard.com\n\t(dfj612yhrgyx302h3jwwy-3.rev.dnainternet.fi\n\t[IPv6:2001:14ba:21f5:5b00:ce28:277f:58d7:3ca4])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 9DFFB2C6;\n\tFri, 28 Jun 2019 14:35:10 +0200 (CEST)"],"DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1561725310;\n\tbh=sRegGgqZ+eRtAZvxsYpnIutnZHwwn+PwzezfqP+Evcg=;\n\th=Date:From:To:Cc:Subject:References:In-Reply-To:From;\n\tb=WvlxaP0f3b2H0TENBA2eu287U0EI30tMl0WZoXTQfioZ5P6XLLnNuUnyJ1F+UA5PS\n\tdSD97tTsE7OXKQ5/bZepIUF3v6/JDlizqpQQNV4vkzsyeinZWsiItonbqhH7UHMi0R\n\tzU/dcuJzrg32eDyph6d08x1b1UC4/+ony90oZTRo=","Date":"Fri, 28 Jun 2019 15:34:52 +0300","From":"Laurent Pinchart ","To":"Jacopo Mondi ","Cc":"Niklas =?utf-8?q?S=C3=B6derlund?= ,\n\tlibcamera-devel@lists.libcamera.org","Message-ID":"<20190628123452.GF4779@pendragon.ideasonboard.com>","References":"<20190626173543.2257-1-niklas.soderlund@ragnatech.se>\n\t<20190628060748.sglsalponiqdagw5@uno.localdomain>","MIME-Version":"1.0","Content-Type":"text/plain; charset=utf-8","Content-Disposition":"inline","Content-Transfer-Encoding":"8bit","In-Reply-To":"<20190628060748.sglsalponiqdagw5@uno.localdomain>","User-Agent":"Mutt/1.10.1 (2018-07-13)","Subject":"Re: [libcamera-devel] [PATCH] libcamera: v4l2_device: Fix\n\tvariable-sized object initialization","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.23","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","X-List-Received-Date":"Fri, 28 Jun 2019 12:35:11 -0000"}},{"id":2054,"web_url":"https://patchwork.libcamera.org/comment/2054/","msgid":"<20190628150940.b3swcepeipxxndao@uno.localdomain>","date":"2019-06-28T15:09:40","subject":"Re: [libcamera-devel] [PATCH] libcamera: v4l2_device: Fix\n\tvariable-sized object initialization","submitter":{"id":3,"url":"https://patchwork.libcamera.org/api/people/3/","name":"Jacopo Mondi","email":"jacopo@jmondi.org"},"content":"Hi Laurent,\n\nOn Fri, Jun 28, 2019 at 03:34:52PM +0300, Laurent Pinchart wrote:\n> Hi Jacopo,\n>\n> On Fri, Jun 28, 2019 at 08:07:48AM +0200, Jacopo Mondi wrote:\n> > Hi Niklas,\n> > sorry, I didn't test on clang. It should become a standard practice\n> > since it's the default compiler used for building, ie, Cros..\n> >\n> > On Wed, Jun 26, 2019 at 07:35:43PM +0200, Nklas Söderlund wrote:\n> > > Compiling with clang renders errors as a variable-sized arrays are not\n> > > allowed to be initialized, solve this by using memset() instead.\n> > >\n> > > ../../src/libcamera/v4l2_device.cpp:155:37: error: variable-sized object may not be initialized\n> > > const V4L2ControlInfo *controlInfo[count] = {};\n> > > ^~~~~\n> > > ../../src/libcamera/v4l2_device.cpp:156:36: error: variable-sized object may not be initialized\n> > > \t struct v4l2_ext_control v4l2Ctrls[count] = {};\n> > > \t\t\t\t\t ^~~~~\n> > > ../../src/libcamera/v4l2_device.cpp:227:37: error: variable-sized object may not be initialized\n> > > \t const V4L2ControlInfo *controlInfo[count] = {};\n> > > \t\t\t\t\t ^~~~~\n> > > ../../src/libcamera/v4l2_device.cpp:228:36: error: variable-sized object may not be initialized\n> > > \t struct v4l2_ext_control v4l2Ctrls[count] = {};\n> > > \t\t\t\t\t ^~~~~\n> > > Fixes: eb068f4e67eedacd (\"libcamera: v4l2_device: Implement get and set controls\")\n> > > Signed-off-by: Niklas Söderlund \n> > > ---\n> > > src/libcamera/v4l2_device.cpp | 13 +++++++++----\n> > > 1 file changed, 9 insertions(+), 4 deletions(-)\n> > >\n> > > diff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp\n> > > index 84758a811c271976..d730df78e1ab2478 100644\n> > > --- a/src/libcamera/v4l2_device.cpp\n> > > +++ b/src/libcamera/v4l2_device.cpp\n> > > @@ -152,8 +152,11 @@ int V4L2Device::getControls(V4L2ControlList *ctrls)\n> > > \tif (count == 0)\n> > > \t\treturn 0;\n> > >\n> > > -\tconst V4L2ControlInfo *controlInfo[count] = {};\n> > > -\tstruct v4l2_ext_control v4l2Ctrls[count] = {};\n> > > +\tconst V4L2ControlInfo *controlInfo[count];\n> >\n> > No need to zero this one.\n> >\n> > > +\tstruct v4l2_ext_control v4l2Ctrls[count];\n> >\n> > We can initialize each entry as we walk them maybe?\n> >\n> > --- a/src/libcamera/v4l2_device.cpp\n> > +++ b/src/libcamera/v4l2_device.cpp\n> > @@ -152,8 +152,8 @@ int V4L2Device::getControls(V4L2ControlList *ctrls)\n> > if (count == 0)\n> > return 0;\n> >\n> > - const V4L2ControlInfo *controlInfo[count] = {};\n> > - struct v4l2_ext_control v4l2Ctrls[count] = {};\n> > + const V4L2ControlInfo *controlInfo[count];\n> > + struct v4l2_ext_control v4l2Ctrls[count];\n> > for (unsigned int i = 0; i < count; ++i) {\n> > const V4L2Control *ctrl = ctrls->getByIndex(i);\n> > const V4L2ControlInfo *info = getControlInfo(ctrl->id());\n> > @@ -164,6 +164,7 @@ int V4L2Device::getControls(V4L2ControlList *ctrls)\n> > }\n> >\n> > controlInfo[i] = info;\n> > + v4l2Ctrls[i] = {};\n> > v4l2Ctrls[i].id = info->id();\n> > }\n> > With the same to be done for setControl()?\n> >\n> > What do you think?\n>\n> Wouldn't a single memset be more efficient ?\n\nProbably yes, as we need to walk all entries anyway.\n\n\n>\n> > > +\tmemset(controlInfo, 0, count * sizeof(controlInfo[0]));\n> > > +\tmemset(v4l2Ctrls, 0, count * sizeof(v4l2Ctrls[0]));\n> > > +\n> > > \tfor (unsigned int i = 0; i < count; ++i) {\n> > > \t\tconst V4L2Control *ctrl = ctrls->getByIndex(i);\n> > > \t\tconst V4L2ControlInfo *info = getControlInfo(ctrl->id());\n> > > @@ -224,8 +227,10 @@ int V4L2Device::setControls(V4L2ControlList *ctrls)\n> > > \tif (count == 0)\n> > > \t\treturn 0;\n> > >\n> > > -\tconst V4L2ControlInfo *controlInfo[count] = {};\n> > > -\tstruct v4l2_ext_control v4l2Ctrls[count] = {};\n> > > +\tconst V4L2ControlInfo *controlInfo[count];\n> > > +\tstruct v4l2_ext_control v4l2Ctrls[count];\n> > > +\tmemset(controlInfo, 0, count * sizeof(controlInfo[0]));\n> > > +\tmemset(v4l2Ctrls, 0, count * sizeof(v4l2Ctrls[0]));\n> > >\n> > > \tfor (unsigned int i = 0; i < count; ++i) {\n> > > \t\tconst V4L2Control *ctrl = ctrls->getByIndex(i);\n>\n> --\n> Regards,\n>\n> Laurent Pinchart","headers":{"Return-Path":"","Received":["from relay7-d.mail.gandi.net (relay7-d.mail.gandi.net\n\t[217.70.183.200])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 65D0A60BF9\n\tfor ;\n\tFri, 28 Jun 2019 17:08:28 +0200 (CEST)","from uno.localdomain\n\t(host107-52-dynamic.246-95-r.retail.telecomitalia.it [95.246.52.107])\n\t(Authenticated sender: jacopo@jmondi.org)\n\tby relay7-d.mail.gandi.net (Postfix) with ESMTPSA id B826120013;\n\tFri, 28 Jun 2019 15:08:25 +0000 (UTC)"],"X-Originating-IP":"95.246.52.107","Date":"Fri, 28 Jun 2019 17:09:40 +0200","From":"Jacopo Mondi ","To":"Laurent Pinchart ","Cc":"Niklas =?utf-8?q?S=C3=B6derlund?= ,\n\tlibcamera-devel@lists.libcamera.org","Message-ID":"<20190628150940.b3swcepeipxxndao@uno.localdomain>","References":"<20190626173543.2257-1-niklas.soderlund@ragnatech.se>\n\t<20190628060748.sglsalponiqdagw5@uno.localdomain>\n\t<20190628123452.GF4779@pendragon.ideasonboard.com>","MIME-Version":"1.0","Content-Type":"multipart/signed; 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