[PATCH] libcamera: base: log: Fix uninitialized variable warning

[Barnabás Pőcze]

Hi


2025. március 2., vasárnap 3:09 keltezéssel, Laurent Pinchart <laurent.pinchart at ideasonboard.com> írta:

> gcc 13.3.0, cross-compiling from amd64 to arm64, warns about a possibly
> uninitialized variable in Logger::parseLogLevel():

Yet it has no problems with it when not cross compiling:
https://gitlab.freedesktop.org/camera/libcamera/-/jobs/71959259 ...

> 
> src/libcamera/base/log.cpp: In static member function ‘static libcamera::LogSeverity libcamera::Logger::parseLogLevel(std::string_view)’:
> ../../src/libcamera/base/log.cpp:694:55: error: ‘severity’ may be used uninitialized [-Werror=maybe-uninitialized]
>   694 |                 if (ec != std::errc() || *end != '\0' || severity > LogFatal)
>       |                     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
> src/libcamera/base/log.cpp:690:22: note: ‘severity’ was declared here
>   690 |         unsigned int severity;
>       |                      ^~~~~~~~
> 
> This appears to be a false positive, as the std::from_chars() function
> should set severity value when it returns without an error. Still, the
> warning is easy to solve, so fix it by initializing the severity
> variable.

I am pretty sure it is false positive, barring any bugs in from_chars(), unfortunate...


Regards,
Barnabás Pőcze


> 
> Fixes: 8fa119e0b50f ("libcamera: base: log: Use `std::from_chars()`")
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> ---
>  src/libcamera/base/log.cpp | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/src/libcamera/base/log.cpp b/src/libcamera/base/log.cpp
> index 6a040b59290a..8bf3e1daa9c6 100644
> --- a/src/libcamera/base/log.cpp
> +++ b/src/libcamera/base/log.cpp
> @@ -687,14 +687,13 @@ LogSeverity Logger::parseLogLevel(std::string_view level)
>  		"FATAL",
>  	};
> 
> -	unsigned int severity;
> +	unsigned int severity = LogInvalid;
> 
>  	if (std::isdigit(level[0])) {
>  		auto [end, ec] = std::from_chars(level.data(), level.data() + level.size(), severity);
>  		if (ec != std::errc() || *end != '\0' || severity > LogFatal)
>  			severity = LogInvalid;
>  	} else {
> -		severity = LogInvalid;
>  		for (unsigned int i = 0; i < std::size(names); ++i) {
>  			if (names[i] == level) {
>  				severity = i;
> 
> base-commit: c0a58b97989f7d529f1469b2c2f8705ff55d3af4
> --
> Regards,
> 
> Laurent Pinchart
>