Fix cs_loader process crash on missing TPA directory (#789)

source/loaders/cs_loader/CMakeLists.txt

@@ -251,7 +251,7 @@ loader_configuartion_end_development()
 
 # Install
 loader_configuration_begin(cs_loader "${CS_LOADER_CONFIG_TEMPLATE}")
-set(DOTNET_CORE_LOADER_ASSEMBLY_PATH ${PROJECT_OUTPUT_DIR}/CSLoader.dll)
+set(DOTNET_CORE_LOADER_ASSEMBLY_PATH ${CMAKE_INSTALL_PREFIX}/${INSTALL_LIB}/CSLoader.dll)
 loader_configuartion_end_install()
 
 #

source/loaders/cs_loader/include/cs_loader/netcore_linux.h

@@ -16,12 +16,13 @@
  *	See the License for the specific language governing permissions and
  *	limitations under the License.
  *
-*/
+ */
 
 #ifndef _NETCORELINUX_H_
 #define _NETCORELINUX_H_
 
 #include <cs_loader/netcore.h>
+#include <log/log.h>
 
 #include <dynlink/dynlink.h>
 
@@ -108,17 +109,31 @@ class netcore_linux : public netcore
 
 	bool LoadMain();
 
-	void AddFilesFromDirectoryToTpaList(std::string directory, std::string &tpaList)
+	bool AddFilesFromDirectoryToTpaList(std::string directory, std::string &tpaList)
 	{
-		for (auto &dirent : fs::directory_iterator(directory))
+		// Use the error_code overload so it can't throw an uncaught filesystem_error
+		std::error_code ec;
+		fs::directory_iterator it(directory, ec);
+		if (ec)
+		{
+			// Bad config directory, skip gracefully instead of std::terminate
+			log_write("metacall", LOG_LEVEL_ERROR, "cs_loader: skipping unreadable TPA directory '%s' (%s)",
+				directory.c_str(), ec.message().c_str());
+			return false;
+		}
+
+		for (const auto &dirent : it)
 		{
 			std::string path = dirent.path();
 
-			if (!path.compare(path.length() - 4, 4, ".dll"))
+			// Length guard avoids size_t underflow for names shorter than 4 chars
+			if (path.length() >= 4 && path.compare(path.length() - 4, 4, ".dll") == 0)
 			{
 				tpaList.append(path + ":");
 			}
 		}
+
+		return true;
 	}
 
 public:

source/loaders/cs_loader/source/netcore_linux.cpp

@@ -84,7 +84,10 @@ bool netcore_linux::ConfigAssemblyName()
 		if (this->dotnet_loader_assembly_path[0] == '/')
 		{
 			this->managedAssemblyFullName.append(this->dotnet_loader_assembly_path);
-			AddFilesFromDirectoryToTpaList(dotnet_loader_assembly_directory, tpaList);
+			if (AddFilesFromDirectoryToTpaList(dotnet_loader_assembly_directory, tpaList) == false)
+			{
+				return false;
+			}
 		}
 		else
 		{
@@ -108,7 +111,10 @@ bool netcore_linux::ConfigAssemblyName()
 	this->nativeDllSearchDirs.append(":");
 	this->nativeDllSearchDirs.append(this->runtimePath);
 
-	AddFilesFromDirectoryToTpaList(this->runtimePath, tpaList);
+	if (AddFilesFromDirectoryToTpaList(this->runtimePath, tpaList) == false)
+	{
+		return false;
+	}
 
 	log_write("metacall", LOG_LEVEL_DEBUG, "NetCore application absolute path: %s", this->appPath);
 

source/tests/CMakeLists.txt

@@ -221,7 +221,7 @@ add_subdirectory(metacall_csharp_static_class_test)
 # TODO:
 # add_subdirectory(metacall_csharp_function_test)
 # add_subdirectory(metacall_csharp_empty_configuration_test)
-# add_subdirectory(metacall_csharp_invalid_configuration_test)
+add_subdirectory(metacall_csharp_invalid_configuration_test)
 add_subdirectory(metacall_julia_test)
 add_subdirectory(metacall_java_test)
 add_subdirectory(metacall_wasm_test)

source/tests/metacall_csharp_invalid_configuration_test/source/metacall_csharp_invalid_configuration_test.cpp

@@ -45,7 +45,7 @@ TEST_F(metacall_csharp_invalid_configuration_test, DefaultConstructor)
 		"\t}\n"
 		"}\n";
 
-	ASSERT_EQ((int)0, (int)metacall_load_from_memory("cs", sum, sizeof(sum), NULL));
+	ASSERT_NE((int)0, (int)metacall_load_from_memory("cs", sum, sizeof(sum), NULL));
 
 	metacall_destroy();
 }