[libcamera-devel] [PATCH 05/16] libcamera: Separate source and build path helpers
Hirokazu Honda
hiroh at chromium.org
Fri Jun 25 05:22:07 CEST 2021
Hi Kieran, thank you for the patch.
On Fri, Jun 25, 2021 at 10:35 AM Kieran Bingham
<kieran.bingham at ideasonboard.com> wrote:
>
> The libcameraSourcePath and libcameraBuildPath helper functions are
> internal and specific to libcamera needs while operating with the meson
> build system.
>
> In preparation for the upcoming move of utils to a common library, move
> these helpers out of utils and into their own build unit.
>
> Signed-off-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
> ---
> include/libcamera/internal/meson.build | 1 +
> include/libcamera/internal/source-paths.h | 19 ++++
> src/libcamera/meson.build | 1 +
> src/libcamera/source-paths.cpp | 129 ++++++++++++++++++++++
> src/libcamera/utils.cpp | 102 -----------------
> 5 files changed, 150 insertions(+), 102 deletions(-)
> create mode 100644 include/libcamera/internal/source-paths.h
> create mode 100644 src/libcamera/source-paths.cpp
>
> diff --git a/include/libcamera/internal/meson.build b/include/libcamera/internal/meson.build
> index f019cfb3b0de..e5088177fe8e 100644
> --- a/include/libcamera/internal/meson.build
> +++ b/include/libcamera/internal/meson.build
> @@ -39,6 +39,7 @@ libcamera_internal_headers = files([
> 'process.h',
> 'pub_key.h',
> 'semaphore.h',
> + 'source-paths.h',
According to coding style guide
(https://libcamera.org/coding-style.html), there is no rule about a
file name.
But it seems like we use the snake case for file names. So,
source_paths.h and source_paths.cpp?
> 'sysfs.h',
> 'thread.h',
> 'timer.h',
> diff --git a/include/libcamera/internal/source-paths.h b/include/libcamera/internal/source-paths.h
> new file mode 100644
> index 000000000000..2591ebb1081b
> --- /dev/null
> +++ b/include/libcamera/internal/source-paths.h
> @@ -0,0 +1,19 @@
> +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> +/*
> + * Copyright (C) 2021, Google Inc.
> + *
> + * source-paths.h - Identify libcamera source and build paths
> + */
> +#ifndef __LIBCAMERA_INTERNAL_SOURCE_PATHS_H__
> +#define __LIBCAMERA_INTERNAL_SOURCE_PATHS_H__
> +
> +#include <string>
> +
> +namespace libcamera::utils {
> +
> +std::string libcameraBuildPath();
> +std::string libcameraSourcePath();
> +
> +} /* namespace libcamera::utils */
> +
> +#endif /* __LIBCAMERA_INTERNAL_SOURCE_PATHS_H__ */
> diff --git a/src/libcamera/meson.build b/src/libcamera/meson.build
> index 387d20843203..e792094f5798 100644
> --- a/src/libcamera/meson.build
> +++ b/src/libcamera/meson.build
> @@ -46,6 +46,7 @@ libcamera_sources = files([
> 'request.cpp',
> 'semaphore.cpp',
> 'signal.cpp',
> + 'source-paths.cpp',
> 'stream.cpp',
> 'sysfs.cpp',
> 'thread.cpp',
> diff --git a/src/libcamera/source-paths.cpp b/src/libcamera/source-paths.cpp
> new file mode 100644
> index 000000000000..b39f5f853e39
> --- /dev/null
> +++ b/src/libcamera/source-paths.cpp
> @@ -0,0 +1,129 @@
> +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> +/*
> + * Copyright (C) 2021, Google Inc.
> + *
> + * source-paths.cpp - Identify libcamera source and build paths
> + */
> +
> +#include "libcamera/internal/source-paths.h"
> +
> +#include <dlfcn.h>
> +#include <elf.h>
> +#include <link.h>
> +#include <sys/stat.h>
> +
> +#include "libcamera/internal/utils.h"
> +
> +/**
> + * \file source-paths.h
> + * \brief Identify the build and source path of a not-yet-installed library
> + */
> +
> +/* musl doesn't declare _DYNAMIC in link.h, declare it manually. */
> +extern ElfW(Dyn) _DYNAMIC[];
> +
> +namespace libcamera::utils {
> +
> +/**
> + * \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;
> +}
> +
isLIbcameraInstalled() should be put in anonymous namespace as it is
used only in .cc file.
With these nits,
Reviewed-by: Hirokazu Honda<hiroh at chromium.org>
> +/**
> + * \brief Retrieve the path to the build directory
> + *
> + * During development, it is useful to run libcamera binaries directly from the
> + * build directory without installing them. This function helps components that
> + * need to locate resources in the build tree, such as IPA modules or IPA proxy
> + * workers, by providing them with the path to the root of the build directory.
> + * Callers can then use it to complement or override searches in system-wide
> + * directories.
> + *
> + * If libcamera has been installed, the build directory path is not available
> + * and this function returns an empty string.
> + *
> + * \return The path to the build directory if running from a build, or an empty
> + * string otherwise
> + */
> +std::string libcameraBuildPath()
> +{
> + if (isLibcameraInstalled())
> + return std::string();
> +
> + Dl_info info;
> +
> + /* Look up our own symbol. */
> + int ret = dladdr(reinterpret_cast<void *>(libcameraBuildPath), &info);
> + if (ret == 0)
> + return std::string();
> +
> + std::string path = dirname(info.dli_fname) + "/../../";
> +
> + char *real = realpath(path.c_str(), nullptr);
> + if (!real)
> + return std::string();
> +
> + path = real;
> + free(real);
> +
> + return path + "/";
> +}
> +
> +/**
> + * \brief Retrieve the path to the source directory
> + *
> + * During development, it is useful to run libcamera binaries directly from the
> + * build directory without installing them. This function helps components that
> + * need to locate resources in the source tree, such as IPA configuration
> + * files, by providing them with the path to the root of the source directory.
> + * Callers can then use it to complement or override searches in system-wide
> + * directories.
> + *
> + * If libcamera has been installed, the source directory path is not available
> + * and this function returns an empty string.
> + *
> + * \return The path to the source directory if running from a build directory,
> + * or an empty string otherwise
> + */
> +std::string libcameraSourcePath()
> +{
> + std::string path = libcameraBuildPath();
> + if (path.empty())
> + return std::string();
> +
> + path += "source";
> +
> + char *real = realpath(path.c_str(), nullptr);
> + if (!real)
> + return std::string();
> +
> + path = real;
> + free(real);
> +
> + struct stat statbuf;
> + int ret = stat(path.c_str(), &statbuf);
> + if (ret < 0 || (statbuf.st_mode & S_IFMT) != S_IFDIR)
> + return std::string();
> +
> + return path + "/";
> +}
> +
> +} /* namespace libcamera::utils */
> diff --git a/src/libcamera/utils.cpp b/src/libcamera/utils.cpp
> index 49b8fc9e211f..42f82d6158dd 100644
> --- a/src/libcamera/utils.cpp
> +++ b/src/libcamera/utils.cpp
> @@ -351,108 +351,6 @@ std::string toAscii(const std::string &str)
> return ret;
> }
>
> -/**
> - * \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 Retrieve the path to the build directory
> - *
> - * During development, it is useful to run libcamera binaries directly from the
> - * build directory without installing them. This function helps components that
> - * need to locate resources in the build tree, such as IPA modules or IPA proxy
> - * workers, by providing them with the path to the root of the build directory.
> - * Callers can then use it to complement or override searches in system-wide
> - * directories.
> - *
> - * If libcamera has been installed, the build directory path is not available
> - * and this function returns an empty string.
> - *
> - * \return The path to the build directory if running from a build, or an empty
> - * string otherwise
> - */
> -std::string libcameraBuildPath()
> -{
> - if (isLibcameraInstalled())
> - return std::string();
> -
> - Dl_info info;
> -
> - /* Look up our own symbol. */
> - int ret = dladdr(reinterpret_cast<void *>(libcameraBuildPath), &info);
> - if (ret == 0)
> - return std::string();
> -
> - std::string path = dirname(info.dli_fname) + "/../../";
> -
> - char *real = realpath(path.c_str(), nullptr);
> - if (!real)
> - return std::string();
> -
> - path = real;
> - free(real);
> -
> - return path + "/";
> -}
> -
> -/**
> - * \brief Retrieve the path to the source directory
> - *
> - * During development, it is useful to run libcamera binaries directly from the
> - * build directory without installing them. This function helps components that
> - * need to locate resources in the source tree, such as IPA configuration
> - * files, by providing them with the path to the root of the source directory.
> - * Callers can then use it to complement or override searches in system-wide
> - * directories.
> - *
> - * If libcamera has been installed, the source directory path is not available
> - * and this function returns an empty string.
> - *
> - * \return The path to the source directory if running from a build directory,
> - * or an empty string otherwise
> - */
> -std::string libcameraSourcePath()
> -{
> - std::string path = libcameraBuildPath();
> - if (path.empty())
> - return std::string();
> -
> - path += "source";
> -
> - char *real = realpath(path.c_str(), nullptr);
> - if (!real)
> - return std::string();
> -
> - path = real;
> - free(real);
> -
> - struct stat statbuf;
> - int ret = stat(path.c_str(), &statbuf);
> - if (ret < 0 || (statbuf.st_mode & S_IFMT) != S_IFDIR)
> - return std::string();
> -
> - return path + "/";
> -}
> -
> /**
> * \fn alignDown(unsigned int value, unsigned int alignment)
> * \brief Align \a value down to \a alignment
> --
> 2.30.2
>
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