[libcamera-devel] [PATCH LIBCAMERA v4 3/5] libcamera: utils: Move libcamera build path lookup to utis

[Laurent Pinchart]

Hi Kaaira,

Thank you for the patch.

In the subject line, s/utis/utils/

Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

If this is the only change needed in the series, there's no need to
resubmit, Kieran will fix this when applying.

On Wed, Mar 18, 2020 at 08:54:25PM +0530, Kaaira Gupta wrote:
> The IPA proxy manager will need to find the libcamera build path exactly
> the same way as the IPA module mnager. Move the isLibcameraInstalled()
> and libcameraPath() functions to utils to make them reusable.
> 
> Signed-off-by: Kaaira Gupta <kgupta at es.iitr.ac.in>
> ---
>  src/libcamera/include/utils.h |  4 +++
>  src/libcamera/ipa_manager.cpp | 36 ++-----------------------
>  src/libcamera/utils.cpp       | 49 +++++++++++++++++++++++++++++++++++
>  3 files changed, 55 insertions(+), 34 deletions(-)
> 
> diff --git a/src/libcamera/include/utils.h b/src/libcamera/include/utils.h
> index 9405977..bc96e79 100644
> --- a/src/libcamera/include/utils.h
> +++ b/src/libcamera/include/utils.h
> @@ -143,6 +143,10 @@ private:
>  
>  details::StringSplitter split(const std::string &str, const std::string &delim);
>  
> +bool isLibcameraInstalled();
> +
> +std::string libcameraPath();
> +
>  } /* namespace utils */
>  
>  } /* namespace libcamera */
> diff --git a/src/libcamera/ipa_manager.cpp b/src/libcamera/ipa_manager.cpp
> index 238433d..0bd280c 100644
> --- a/src/libcamera/ipa_manager.cpp
> +++ b/src/libcamera/ipa_manager.cpp
> @@ -9,9 +9,6 @@
>  
>  #include <algorithm>
>  #include <dirent.h>
> -#include <dlfcn.h>
> -#include <elf.h>
> -#include <link.h>
>  #include <string.h>
>  #include <sys/types.h>
>  
> @@ -27,35 +24,6 @@
>   * \brief Image Processing Algorithm module manager
>   */
>  
> -static bool isLibcameraInstalled()
> -{
> -	/* musl doesn't declare _DYNAMIC in link.h, declare it manually. */
> -	extern ElfW(Dyn) _DYNAMIC[];
> -
> -	/*
> -	 * DT_RUNPATH (DT_RPATH when the linker uses old dtags) is removed on
> -	 * install.
> -	 */
> -	for (const ElfW(Dyn) *dyn = _DYNAMIC; dyn->d_tag != DT_NULL; ++dyn) {
> -		if (dyn->d_tag == DT_RUNPATH || dyn->d_tag == DT_RPATH)
> -			return false;
> -	}
> -
> -	return true;
> -}
> -
> -static std::string libcameraPath()
> -{
> -	Dl_info info;
> -
> -	/* Look up our own symbol. */
> -	int ret = dladdr(reinterpret_cast<void *>(libcameraPath), &info);
> -	if (ret == 0)
> -		return nullptr;
> -
> -	return info.dli_fname;
> -}
> -
>  namespace libcamera {
>  
>  LOG_DEFINE_CATEGORY(IPAManager)
> @@ -151,8 +119,8 @@ IPAManager::IPAManager()
>  	 * path for the IPA from that point. We need to recurse one level of
>  	 * sub-directories to match the build tree.
>  	 */
> -	if (!isLibcameraInstalled()) {
> -		std::string ipaBuildPath = utils::dirname(libcameraPath()) + "/../ipa";
> +	if (!utils::isLibcameraInstalled()) {
> +		std::string ipaBuildPath = utils::dirname(utils::libcameraPath()) + "/../ipa";
>  		constexpr int maxDepth = 1;
>  
>  		LOG(IPAManager, Info)
> diff --git a/src/libcamera/utils.cpp b/src/libcamera/utils.cpp
> index f566e88..7e118fa 100644
> --- a/src/libcamera/utils.cpp
> +++ b/src/libcamera/utils.cpp
> @@ -7,7 +7,10 @@
>  
>  #include "utils.h"
>  
> +#include <dlfcn.h>
> +#include <elf.h>
>  #include <iomanip>
> +#include <link.h>
>  #include <sstream>
>  #include <stdlib.h>
>  #include <string.h>
> @@ -18,6 +21,9 @@
>   * \brief Miscellaneous utility functions
>   */
>  
> +/* musl doesn't declare _DYNAMIC in link.h, declare it manually. */
> +extern ElfW(Dyn) _DYNAMIC[];
> +
>  namespace libcamera {
>  
>  namespace utils {
> @@ -310,6 +316,49 @@ details::StringSplitter split(const std::string &str, const std::string &delim)
>  	return details::StringSplitter(str, delim);
>  }
>  
> +/**
> + * \brief Check if libcamera is installed or not
> + *
> + * Utilise the build_rpath dynamic tag which is stripped out by meson at
> + * install time to determine at runtime if the library currently executing
> + * has been installed or not.
> + *
> + * \return True if libcamera is installed, false otherwise
> + */
> +bool isLibcameraInstalled()
> +{
> +	/*
> +	 * DT_RUNPATH (DT_RPATH when the linker uses old dtags) is removed on
> +	 * install.
> +	 */
> +	for (const ElfW(Dyn) *dyn = _DYNAMIC; dyn->d_tag != DT_NULL; ++dyn) {
> +		if (dyn->d_tag == DT_RUNPATH || dyn->d_tag == DT_RPATH)
> +			return false;
> +	}
> +
> +	return true;
> +}
> +
> +/**
> + * \brief Identify the libcamera.so path
> + *
> + * This function locates the running libcamera.so and returns its full path,
> + * including the file name.
> + *
> + * \return A string stating the path
> + */
> +std::string libcameraPath()
> +{
> +	Dl_info info;
> +
> +	/* Look up our own symbol. */
> +	int ret = dladdr(reinterpret_cast<void *>(libcameraPath), &info);
> +	if (ret == 0)
> +		return nullptr;
> +
> +	return info.dli_fname;
> +}
> +
>  } /* namespace utils */
>  
>  } /* namespace libcamera */

-- 
Regards,

Laurent Pinchart