[{"id":38005,"web_url":"https://patchwork.libcamera.org/comment/38005/","msgid":"<176961779665.783702.17427637677557728457@ping.linuxembedded.co.uk>","date":"2026-01-28T16:29:56","subject":"Re: [PATCH] libcamera: yaml_parser: Fix uninitialized variable\n\twarning","submitter":{"id":4,"url":"https://patchwork.libcamera.org/api/people/4/","name":"Kieran Bingham","email":"kieran.bingham@ideasonboard.com"},"content":"Quoting Laurent Pinchart (2026-01-28 16:26:49)\n> gcc 14.3.0, cross-compiling from amd64 to arm64, warns about a possibly\n> uninitialized variable in YamlObject::Getter<>::get():\n> \n> In file included from ../../include/libcamera/internal/yaml_parser.h:12,\n> from ../../src/libcamera/yaml_parser.cpp:8:\n> In constructor ‘constexpr std::_Optional_payload_base<_Tp>::_Storage<_Up, >::_Storage(std::in_place_t, _Args&& ...) [with _Args = {unsigned char}; _Up = unsigned char; bool = true; _Tp = unsigned char]’,\n> inlined from ‘constexpr std::_Optional_payload_base<_Tp>::_Optional_payload_base(std::in_place_t, _Args&& ...) [with _Args = {unsigned char}; _Tp = unsigned char]’ at include/c++/14.3.0/optional:122:4,\n> inlined from ‘constexpr std::_Optional_payload::_Optional_payload(std::in_place_t, _Args&& ...) [with _Args = {unsigned char}][inherited from std::_Optional_payload_base]’ at include/c++/14.3.0/optional:337:42,\n> inlined from ‘constexpr std::_Optional_base<_Tp, true, true>::_Optional_base(std::in_place_t, _Args&& ...) [with _Args = {unsigned char}; typename std::enable_if, bool>::type = false; _Tp = unsigned char]’ at include/c++/14.3.0/optional:648:4,\n> inlined from ‘constexpr std::optional<_Tp>::optional(_Up&&) [with _Up = unsigned char; typename std::enable_if<__and_v, typename std::remove_cv::type>::type> >, std::__not_::type>::type> >, std::is_constructible<_T1, _U1>, std::is_convertible<_Iter, _Iterator> >, bool>::type = true; _Tp = unsigned char]’ at include/c++/14.3.0/optional:747:47,\n> inlined from ‘std::optional<_Tp> libcamera::YamlObject::Getter || is_same_v) || is_same_v) || is_same_v) || is_same_v) || is_same_v), void>::type>::get(const libcamera::YamlObject&) const [with T = unsigned char]’ at ../../src/libcamera/yaml_parser.cpp:172:10:\n> include/c++/14.3.0/optional:210:15: error: ‘value’ may be used uninitialized [-Werror=maybe-uninitialized]\n> 210 | : _M_value(std::forward<_Args>(__args)...)\n> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n> ../../src/libcamera/yaml_parser.cpp: In member function ‘std::optional<_Tp> libcamera::YamlObject::Getter || is_same_v) || is_same_v) || is_same_v) || is_same_v) || is_same_v), void>::type>::get(const libcamera::YamlObject&) const [with T = unsigned char]’:\n> ../../src/libcamera/yaml_parser.cpp:165:19: note: ‘value’ was declared here\n> 165 | T value;\n> | ^~~~~\n> \n> This appears to be a false positive, as the std::from_chars() function\n> should set value when it returns without an error. Commit bb1d216113bc\n> (\"libcamera: base: log: Fix uninitialized variable warning\") fixed a\n> similar warning with gcc 13.3.0.\n> \n> The warning is easy to work around by initializing the variable, and\n> doing so shouldn't be too costly as the type T is restricted to being an\n> integer. Fix the build by doing so.\n> \n> Signed-off-by: Laurent Pinchart \n\nOdd that this hasn't come up elsewhere but it's not a difficult fix so:\n\n\nReviewed-by: Kieran Bingham \n\n> ---\n> src/libcamera/yaml_parser.cpp | 2 +-\n> 1 file changed, 1 insertion(+), 1 deletion(-)\n> \n> diff --git a/src/libcamera/yaml_parser.cpp b/src/libcamera/yaml_parser.cpp\n> index a5e424615c26..e13b5faedd81 100644\n> --- a/src/libcamera/yaml_parser.cpp\n> +++ b/src/libcamera/yaml_parser.cpp\n> @@ -162,7 +162,7 @@ struct YamlObject::Getter return std::nullopt;\n> \n> const std::string &str = obj.value_;\n> - T value;\n> + T value = {};\n> \n> auto [ptr, ec] = std::from_chars(str.data(), str.data() + str.size(),\n> value);\n> \n> base-commit: 186e5cf9ac74cc495384c0af5a055c33a43d9ecc\n> -- \n> Regards,\n> \n> Laurent Pinchart\n>","headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id 85E07C3226\n\tfor ;\n\tWed, 28 Jan 2026 16:30:01 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id C205961FD0;\n\tWed, 28 Jan 2026 17:30:00 +0100 (CET)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 7E62361FC4\n\tfor ;\n\tWed, 28 Jan 2026 17:29:59 +0100 (CET)","from monstersaurus.ideasonboard.com\n\t(cpc89244-aztw30-2-0-cust6594.18-1.cable.virginm.net [86.31.185.195])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 6EDFBE70;\n\tWed, 28 Jan 2026 17:29:22 +0100 (CET)"],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"ezVAfv4x\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1769617762;\n\tbh=8uKXf3dchhCHCBalWol59gwutGb5kIw/oeHe2oaqWgM=;\n\th=In-Reply-To:References:Subject:From:To:Date:From;\n\tb=ezVAfv4xGqXD90bq0ELvAEv184tCt64S7srqI4wGRB22ns2trFVWuxLZ11KAzM+3P\n\t/hmcCb9rgYLr/Guu3KL52u5OxmIVplTVuPe+ZUEDx8fOE5F0MZ00Dzo8b40DGPBzmM\n\twSrP93UXvnCD8emoGHkRVBGy9Br9Okl+BzYrbTXw=","Content-Type":"text/plain; charset=\"utf-8\"","MIME-Version":"1.0","Content-Transfer-Encoding":"quoted-printable","In-Reply-To":"<20260128162649.3263861-1-laurent.pinchart@ideasonboard.com>","References":"<20260128162649.3263861-1-laurent.pinchart@ideasonboard.com>","Subject":"Re: [PATCH] libcamera: yaml_parser: Fix uninitialized variable\n\twarning","From":"Kieran Bingham ","To":"Laurent Pinchart ,\n\tlibcamera-devel@lists.libcamera.org","Date":"Wed, 28 Jan 2026 16:29:56 +0000","Message-ID":"<176961779665.783702.17427637677557728457@ping.linuxembedded.co.uk>","User-Agent":"alot/0.9.1","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}},{"id":38007,"web_url":"https://patchwork.libcamera.org/comment/38007/","msgid":"<549f932d-f6f5-456a-9c93-619ce075e04b@ideasonboard.com>","date":"2026-01-28T16:34:45","subject":"Re: [PATCH] libcamera: yaml_parser: Fix uninitialized variable\n\twarning","submitter":{"id":216,"url":"https://patchwork.libcamera.org/api/people/216/","name":"Barnabás Pőcze","email":"barnabas.pocze@ideasonboard.com"},"content":"2026. 01. 28. 17:26 keltezéssel, Laurent Pinchart írta:\n> gcc 14.3.0, cross-compiling from amd64 to arm64, warns about a possibly\n> uninitialized variable in YamlObject::Getter<>::get():\n> \n> In file included from ../../include/libcamera/internal/yaml_parser.h:12,\n> from ../../src/libcamera/yaml_parser.cpp:8:\n> In constructor ‘constexpr std::_Optional_payload_base<_Tp>::_Storage<_Up, >::_Storage(std::in_place_t, _Args&& ...) [with _Args = {unsigned char}; _Up = unsigned char; bool = true; _Tp = unsigned char]’,\n> inlined from ‘constexpr std::_Optional_payload_base<_Tp>::_Optional_payload_base(std::in_place_t, _Args&& ...) [with _Args = {unsigned char}; _Tp = unsigned char]’ at include/c++/14.3.0/optional:122:4,\n> inlined from ‘constexpr std::_Optional_payload::_Optional_payload(std::in_place_t, _Args&& ...) [with _Args = {unsigned char}][inherited from std::_Optional_payload_base]’ at include/c++/14.3.0/optional:337:42,\n> inlined from ‘constexpr std::_Optional_base<_Tp, true, true>::_Optional_base(std::in_place_t, _Args&& ...) [with _Args = {unsigned char}; typename std::enable_if, bool>::type = false; _Tp = unsigned char]’ at include/c++/14.3.0/optional:648:4,\n> inlined from ‘constexpr std::optional<_Tp>::optional(_Up&&) [with _Up = unsigned char; typename std::enable_if<__and_v, typename std::remove_cv::type>::type> >, std::__not_::type>::type> >, std::is_constructible<_T1, _U1>, std::is_convertible<_Iter, _Iterator> >, bool>::type = true; _Tp = unsigned char]’ at include/c++/14.3.0/optional:747:47,\n> inlined from ‘std::optional<_Tp> libcamera::YamlObject::Getter || is_same_v) || is_same_v) || is_same_v) || is_same_v) || is_same_v), void>::type>::get(const libcamera::YamlObject&) const [with T = unsigned char]’ at ../../src/libcamera/yaml_parser.cpp:172:10:\n> include/c++/14.3.0/optional:210:15: error: ‘value’ may be used uninitialized [-Werror=maybe-uninitialized]\n> 210 | : _M_value(std::forward<_Args>(__args)...)\n> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n> ../../src/libcamera/yaml_parser.cpp: In member function ‘std::optional<_Tp> libcamera::YamlObject::Getter || is_same_v) || is_same_v) || is_same_v) || is_same_v) || is_same_v), void>::type>::get(const libcamera::YamlObject&) const [with T = unsigned char]’:\n> ../../src/libcamera/yaml_parser.cpp:165:19: note: ‘value’ was declared here\n> 165 | T value;\n> | ^~~~~\n> \n> This appears to be a false positive, as the std::from_chars() function\n> should set value when it returns without an error. Commit bb1d216113bc\n> (\"libcamera: base: log: Fix uninitialized variable warning\") fixed a\n> similar warning with gcc 13.3.0.\n> \n> The warning is easy to work around by initializing the variable, and\n> doing so shouldn't be too costly as the type T is restricted to being an\n> integer. Fix the build by doing so.\n> \n> Signed-off-by: Laurent Pinchart \n> ---\n\nReviewed-by: Barnabás Pőcze \n\n\n> src/libcamera/yaml_parser.cpp | 2 +-\n> 1 file changed, 1 insertion(+), 1 deletion(-)\n> \n> diff --git a/src/libcamera/yaml_parser.cpp b/src/libcamera/yaml_parser.cpp\n> index a5e424615c26..e13b5faedd81 100644\n> --- a/src/libcamera/yaml_parser.cpp\n> +++ b/src/libcamera/yaml_parser.cpp\n> @@ -162,7 +162,7 @@ struct YamlObject::Getter \t\t\treturn std::nullopt;\n> \n> \t\tconst std::string &str = obj.value_;\n> -\t\tT value;\n> +\t\tT value = {};\n> \n> \t\tauto [ptr, ec] = std::from_chars(str.data(), str.data() + str.size(),\n> \t\t\t\t\t\t value);\n> \n> base-commit: 186e5cf9ac74cc495384c0af5a055c33a43d9ecc","headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id C8F7EC3200\n\tfor ;\n\tWed, 28 Jan 2026 16:34:49 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 2150661FD1;\n\tWed, 28 Jan 2026 17:34:49 +0100 (CET)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 7F31E61FC4\n\tfor ;\n\tWed, 28 Jan 2026 17:34:48 +0100 (CET)","from [192.168.33.40] (185.221.142.123.nat.pool.zt.hu\n\t[185.221.142.123])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 6CBAEE70;\n\tWed, 28 Jan 2026 17:34:11 +0100 (CET)"],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"fObIg9j6\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1769618051;\n\tbh=nD1KWMbzNFOuoTO3s4TqWW4s/dJLeqeR2NwgargFE5M=;\n\th=Date:Subject:To:References:From:In-Reply-To:From;\n\tb=fObIg9j6IcmaZiqidNcpE45gZxassHLGaSEvKMJKIiRldLITcn/XjEmIk1vmJq3P8\n\t+7ysa9ETcF1gFpt17yhxU5DXA6GXAsXKYPgvzxNZko/wdHZSWzAzw6g4QxTV85UbJQ\n\tAreJk/1dF9dIilDM4SWUE73G3qZu96VvBaN/48Qo=","Message-ID":"<549f932d-f6f5-456a-9c93-619ce075e04b@ideasonboard.com>","Date":"Wed, 28 Jan 2026 17:34:45 +0100","MIME-Version":"1.0","User-Agent":"Mozilla Thunderbird","Subject":"Re: [PATCH] libcamera: yaml_parser: Fix uninitialized variable\n\twarning","To":"Laurent Pinchart ,\n\tlibcamera-devel@lists.libcamera.org","References":"<20260128162649.3263861-1-laurent.pinchart@ideasonboard.com>","From":"=?utf-8?q?Barnab=C3=A1s_P=C5=91cze?= ","Content-Language":"en-US, hu-HU","In-Reply-To":"<20260128162649.3263861-1-laurent.pinchart@ideasonboard.com>","Content-Type":"text/plain; charset=UTF-8; format=flowed","Content-Transfer-Encoding":"8bit","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}}]