test: cover shared object folder lookup

Add a CMocka suite around the production shared-object path helper and register it in the existing utility test hierarchy.

Cover directory extraction for a resolvable symbol, invalid symbol and buffer arguments, a zero-sized buffer, and an undersized buffer. These cases protect the path contract used by the library-adjacent mapping lookup.

cmake/src/test/util/CMakeLists.txt

@@ -1,2 +1,3 @@
 add_subdirectory(mem)
-add_subdirectory(str)
+add_subdirectory(proc)
+add_subdirectory(str)

cmake/src/test/util/proc/CMakeLists.txt

@@ -0,0 +1,11 @@
+project(test-util-proc)
+message(STATUS "Project " ${PROJECT_NAME})
+
+set(SRC ${PT_ROOT_TEST}/util/proc)
+
+set(SOURCE_FILES
+        ${SRC}/main.c)
+
+add_executable(${PROJECT_NAME} ${SOURCE_FILES})
+
+target_link_libraries(${PROJECT_NAME} cmocka util dl)

src/test/util/proc/main.c

@@ -0,0 +1,66 @@
+#include <cmocka/cmocka.h>
+#include <dlfcn.h>
+#include <linux/limits.h>
+#include <string.h>
+
+#include "util/proc.h"
+
+static void test_get_folder_path_shared_object(void **state)
+{
+  char path[PATH_MAX];
+  char expected[PATH_MAX];
+  Dl_info info;
+  char *separator;
+
+  assert_true(util_proc_get_folder_path_shared_object(
+      (void *) test_get_folder_path_shared_object, path, sizeof(path)));
+
+  assert_true(dladdr((void *) test_get_folder_path_shared_object, &info));
+  assert_non_null(info.dli_fname);
+  assert_true(strlen(info.dli_fname) < sizeof(expected));
+  strcpy(expected, info.dli_fname);
+  separator = strrchr(expected, '/');
+  assert_non_null(separator);
+
+  if (separator == expected) {
+    separator[1] = '\0';
+  } else {
+    *separator = '\0';
+  }
+
+  assert_string_equal(path, expected);
+}
+
+static void test_get_folder_path_shared_object_invalid_args(void **state)
+{
+  char path[PATH_MAX];
+
+  assert_false(
+      util_proc_get_folder_path_shared_object(NULL, path, sizeof(path)));
+  assert_false(util_proc_get_folder_path_shared_object(
+      (void *) test_get_folder_path_shared_object_invalid_args,
+      NULL,
+      sizeof(path)));
+  assert_false(util_proc_get_folder_path_shared_object(
+      (void *) test_get_folder_path_shared_object_invalid_args, path, 0));
+}
+
+static void test_get_folder_path_shared_object_small_buffer(void **state)
+{
+  char path[1];
+
+  assert_false(util_proc_get_folder_path_shared_object(
+      (void *) test_get_folder_path_shared_object_small_buffer,
+      path,
+      sizeof(path)));
+}
+
+int main(int argc, char *argv[])
+{
+  const struct CMUnitTest tests[] = {
+      cmocka_unit_test(test_get_folder_path_shared_object),
+      cmocka_unit_test(test_get_folder_path_shared_object_invalid_args),
+      cmocka_unit_test(test_get_folder_path_shared_object_small_buffer)};
+
+  return cmocka_run_group_tests(tests, NULL, NULL);
+}