From 2b21e5f7c6a3e94816bb55a16be3e8a8f277d16d Mon Sep 17 00:00:00 2001
From: Steffen Vogel <post@steffenvogel.de>
Date: Mon, 13 Sep 2021 19:14:22 +0200
Subject: [PATCH] remove dependency on std::filesystem

---
 common                    |  2 +-
 include/villas/config.hpp |  5 +----
 lib/CMakeLists.txt        |  4 ----
 lib/config.cpp            | 37 ++++++++++++++++++++++++++++---------
 tests/unit/config.cpp     |  2 --
 5 files changed, 30 insertions(+), 20 deletions(-)

diff --git a/common b/common
index dd9304ca0..3e062fdc0 160000
--- a/common
+++ b/common
@@ -1 +1 @@
-Subproject commit dd9304ca059efffe053b74159ca32b16a5eb4597
+Subproject commit 3e062fdc0f311d9eb4bc541b7a292def71f87cb0
diff --git a/include/villas/config.hpp b/include/villas/config.hpp
index fba5ae197..10dcc9b3d 100644
--- a/include/villas/config.hpp
+++ b/include/villas/config.hpp
@@ -29,13 +29,10 @@
 
 #include <functional>
 #include <regex>
-#include <filesystem>
 
 #include <villas/node/config.h>
 #include <villas/log.hpp>
 
-namespace fs = std::filesystem;
-
 namespace villas {
 namespace node {
 
@@ -76,7 +73,7 @@ protected:
 	json_t * walkStrings(json_t *in, str_walk_fcn_t cb);
 
 	/** Get the include dirs */
-	std::list<fs::path> getIncludeDirs(FILE *f) const;
+	std::list<std::string> getIncludeDirectories(FILE *f) const;
 
 public:
 	json_t *root;
diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index f6794c749..dd58441af 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -40,10 +40,6 @@ if(UNIX AND NOT APPLE)
     list(APPEND LIBRARIES "rt")
 endif()
 
-if(CMAKE_CXX_COMPILER_ID STREQUAL GNU)
-    list(APPEND LIBRARIES "-lstdc++fs")
-endif()
-
 set(LIB_SRC
     config_helper.cpp
     config.cpp
diff --git a/lib/config.cpp b/lib/config.cpp
index 8bd9431f7..bdb25d447 100644
--- a/lib/config.cpp
+++ b/lib/config.cpp
@@ -21,6 +21,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  *********************************************************************************/
 
+#include <linux/limits.h>
 #include <unistd.h>
 #include <libgen.h>
 
@@ -122,16 +123,34 @@ json_t * Config::decode(FILE *f)
 	return root;
 }
 
-std::list<fs::path> Config::getIncludeDirs(FILE *f) const
+std::list<std::string> Config::getIncludeDirectories(FILE *f) const
 {
-	auto uri = fs::read_symlink(fs::path("/proc/self/fd") / std::to_string(fileno(f)));
-	if (isLocalFile(uri)) {
-		return {
-			uri.parent_path()
-		};
+	int ret, fd;
+	char buf[PATH_MAX];
+	char *dir;
+
+	std::list<std::string> dirs;
+
+	dir = getcwd(buf, sizeof(buf));
+	if (dir != nullptr)
+		dirs.push_back(dir);
+
+	fd = fileno(f);
+	if (fd < 0)
+		throw SystemError("Failed to get file descriptor");
+
+	auto path = fmt::format("/proc/self/fd/{}", fd);
+
+	ret = readlink(path.c_str(), buf, sizeof(buf));
+	if (ret > 0) {
+		buf[ret] = 0;
+		if (isLocalFile(buf)) {
+			dir = dirname(buf);
+			dirs.push_back(dir);
+		}
 	}
-	else
-		return { };
+
+	return dirs;
 }
 
 #ifdef WITH_CONFIG
@@ -145,7 +164,7 @@ json_t * Config::libconfigDecode(FILE *f)
 	config_set_auto_convert(&cfg, 1);
 
 	/* Setup libconfig include path. */
-	auto inclDirs = getIncludeDirs(f);
+	auto inclDirs = getIncludeDirectories(f);
 	if (inclDirs.size() > 0) {
 		logger->info("Setting include dir to: {}", inclDirs.front());
 
diff --git a/tests/unit/config.cpp b/tests/unit/config.cpp
index 77e318089..e9f8928d3 100644
--- a/tests/unit/config.cpp
+++ b/tests/unit/config.cpp
@@ -22,13 +22,11 @@
 
 #include <cstdio>
 #include <cstdlib>
-#include <filesystem>
 #include <criterion/criterion.h>
 
 #include <villas/utils.hpp>
 #include <villas/config.hpp>
 
-namespace fs = std::filesystem;
 using namespace villas::node;
 
 // cppcheck-suppress syntaxError