[libcamera-devel] [PATCH v1.1 02/11] libcamera: utils: Add a function to retrieve the libcamera source tree
Laurent Pinchart
laurent.pinchart at ideasonboard.com
Mon Apr 27 14:18:34 CEST 2020
Similarly to libcameraBuildPath(), there's a need to locate resources
within the source tree when running libcamera without installing it.
Support this use case with a new utils::libcameraSourcePath() function.
The implementation uses a symlink from the build root to the source root
in order to avoid hardcoding the path to the source root in the
libcamera.so binary.
Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
---
Changes since v1:
- Use a symlink to the source tree to avoid hardcoding the path in the
libcamera.so binary
---
meson.build | 6 +++++
src/libcamera/include/utils.h | 1 +
src/libcamera/utils.cpp | 49 ++++++++++++++++++++++++++++++++---
3 files changed, 53 insertions(+), 3 deletions(-)
diff --git a/meson.build b/meson.build
index c6e6a934e54e..ec5bc970f5b6 100644
--- a/meson.build
+++ b/meson.build
@@ -93,6 +93,12 @@ if get_option('test')
subdir('test')
endif
+# Create a symlink from the build root to the source root. This is used when
+# running libcamera from the build directory to locate resources in the source
+# directory (such as IPA configuration files).
+run_command('ln', '-fs', meson.source_root(),
+ join_paths(meson.build_root(), 'source'))
+
configure_file(output : 'config.h', configuration : config_h)
pkg_mod = import('pkgconfig')
diff --git a/src/libcamera/include/utils.h b/src/libcamera/include/utils.h
index 242eeded9d50..3334ff16613d 100644
--- a/src/libcamera/include/utils.h
+++ b/src/libcamera/include/utils.h
@@ -188,6 +188,7 @@ private:
details::StringSplitter split(const std::string &str, const std::string &delim);
std::string libcameraBuildPath();
+std::string libcameraSourcePath();
} /* namespace utils */
diff --git a/src/libcamera/utils.cpp b/src/libcamera/utils.cpp
index 97f9b632e45b..a96ca7f40cbd 100644
--- a/src/libcamera/utils.cpp
+++ b/src/libcamera/utils.cpp
@@ -10,10 +10,13 @@
#include <dlfcn.h>
#include <elf.h>
#include <iomanip>
+#include <limits.h>
#include <link.h>
#include <sstream>
#include <stdlib.h>
#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
#include <unistd.h>
/**
@@ -360,9 +363,10 @@ bool isLibcameraInstalled()
*
* 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, 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.
+ * 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.
@@ -385,6 +389,45 @@ std::string libcameraBuildPath()
return dirname(info.dli_fname) + "/../../";
}
+/**
+ * \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 utils */
} /* namespace libcamera */
--
Regards,
Laurent Pinchart
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