[libcamera-devel] [PATCH] hal: Fix comparison of integers of different signs

[Niklas Söderlund]

Hi Laurent,

Thanks for your patch.

On 2019-08-12 14:04:47 +0300, Laurent Pinchart wrote:
> The CameraHalManager::getCameraInfo() validates the camera id it
> receives from the camera service, and in doing so compares it with an
> unsigned integer, generating a compiler error:
> 
> src/android/camera_hal_manager.cpp:121:9: error: comparison of integers of different signs: 'int' and 'unsigned int' [-Werror,-Wsign-compare]
>         if (id >= numCameras() || id < 0) {
>             ~~ ^  ~~~~~~~~~~~~
> 
> Fix this by turning the id into an unsigned int, as camera ids can't be
> negative. If a negative id is received from the camera service it will
> be converted to a large unsigned integer that will fail the comparison
> with numCameras().
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

Reviewed-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>

> ---
>  src/android/camera_hal_manager.cpp | 4 ++--
>  src/android/camera_hal_manager.h   | 2 +-
>  2 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/src/android/camera_hal_manager.cpp b/src/android/camera_hal_manager.cpp
> index 08c759dfd8a1..1e66f63240da 100644
> --- a/src/android/camera_hal_manager.cpp
> +++ b/src/android/camera_hal_manager.cpp
> @@ -113,12 +113,12 @@ unsigned int CameraHalManager::numCameras() const
>  	return cameraManager_->cameras().size();
>  }
>  
> -int CameraHalManager::getCameraInfo(int id, struct camera_info *info)
> +int CameraHalManager::getCameraInfo(unsigned int id, struct camera_info *info)
>  {
>  	if (!info)
>  		return -EINVAL;
>  
> -	if (id >= numCameras() || id < 0) {
> +	if (id >= numCameras()) {
>  		LOG(HAL, Error) << "Invalid camera id '" << id << "'";
>  		return -EINVAL;
>  	}
> diff --git a/src/android/camera_hal_manager.h b/src/android/camera_hal_manager.h
> index 8004aaf660f5..8228623aba90 100644
> --- a/src/android/camera_hal_manager.h
> +++ b/src/android/camera_hal_manager.h
> @@ -30,7 +30,7 @@ public:
>  	int close(CameraProxy *proxy);
>  
>  	unsigned int numCameras() const;
> -	int getCameraInfo(int id, struct camera_info *info);
> +	int getCameraInfo(unsigned int id, struct camera_info *info);
>  
>  private:
>  	void run() override;
> -- 
> Regards,
> 
> Laurent Pinchart
> 
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> libcamera-devel at lists.libcamera.org
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-- 
Regards,
Niklas Söderlund