From df493769a0d71c09898171c47438fc94bdc976b3 Mon Sep 17 00:00:00 2001
From: Kaaira Gupta <kgupta@es.iitr.ac.in>
Date: Wed, 18 Mar 2020 20:54:25 +0530
Subject: libcamera: utils: Move libcamera build path lookup to utils

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@es.iitr.ac.in>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
---
 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 94059776..bc96e79c 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 238433dc..0bd280c2 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 f566e88c..7e118faf 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 */
-- 
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