refactor: Adapt codebase for C++ compilation

CMakeLists.txt

@@ -1,18 +1,24 @@
 cmake_minimum_required(VERSION 3.13)
-project(hwpc-sensor LANGUAGES C)
+project(hwpc-sensor LANGUAGES CXX)
 
 option(WITH_MONGODB "Build with support for MongoDB storage module" ON)
 
-set(CMAKE_C_STANDARD 11)
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
-set(CMAKE_POSITION_INDEPENDENT_CODE ON)
 
 list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
 
-add_compile_options(-Werror -Wall -Wextra -Wpedantic -Wformat=2 -Wnull-dereference -Wno-gnu-statement-expression)
-add_link_options(-Wl,-z,relro,-z,now -pie)
-set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -Og -fsanitize=address,undefined -fno-omit-frame-pointer")
-set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE} -D_FORTIFY_SOURCE=2 -fstack-protector-strong")
+add_compile_options(-Werror -Wall -Wextra -Wformat=2 -fstack-protector-strong -D_FORTIFY_SOURCE=2 -fPIE)
+add_link_options(-pie -Wl,-z,relro,-z,now -Wl,-z,noexecstack -Wl,-z,defs -Wl,--as-needed)
+
+if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
+    # These warnings need to be suppressed temporarily, as the only fix is to rewrite the code in C++
+    add_compile_options(-Wno-deprecated -Wno-c99-designator -Wno-vla-cxx-extension)
+endif()
+
+if (CMAKE_BUILD_TYPE STREQUAL "Debug" AND CMAKE_CXX_COMPILER_ID MATCHES "GNU|Clang")
+    add_compile_options(-Og -fsanitize=address,undefined -fno-omit-frame-pointer)
+    add_link_options(-fsanitize=address,undefined)
+endif()
 
 set(SENSOR_SOURCES
     src/config_cli.c
@@ -51,5 +57,13 @@ if(DEFINED ENV{GIT_TAG} AND DEFINED ENV{GIT_REV})
 endif()
 
 add_executable(hwpc-sensor "${SENSOR_SOURCES}")
+
+foreach(src ${SENSOR_SOURCES})
+    set_source_files_properties(${src} PROPERTIES LANGUAGE CXX)
+endforeach()
+
+target_compile_features(hwpc-sensor PUBLIC cxx_std_20)
+set_target_properties(hwpc-sensor PROPERTIES CXX_EXTENSIONS OFF LINKER_LANGUAGE CXX)
+
 target_include_directories(hwpc-sensor SYSTEM PRIVATE "${LIBPFM_INCLUDE_DIRS}" "${CZMQ_INCLUDE_DIRS}" "${JSONC_INCLUDE_DIRS}" "${MONGOC_INCLUDE_DIRS}")
 target_link_libraries(hwpc-sensor "${LIBPFM_LIBRARIES}" "${CZMQ_LIBRARIES}" "${JSONC_LIBRARIES}" "${MONGOC_LIBRARIES}")

src/config.c

@@ -46,7 +46,7 @@
 struct config *
 config_create(void)
 {
-    struct config *config = malloc(sizeof(struct config));
+    struct config *config = (struct config *) malloc(sizeof(struct config));
 
     if (!config)
         return NULL;
@@ -104,7 +104,7 @@ is_events_group_empty(zhashx_t *events_groups)
 {
     struct events_group *events_group = NULL;
 
-    for (events_group = zhashx_first(events_groups); events_group; events_group = zhashx_next(events_groups)) {
+    for (events_group = (struct events_group *) zhashx_first(events_groups); events_group; events_group = (struct events_group *) zhashx_next(events_groups)) {
         if (zlistx_size(events_group->events) == 0) {
             zsys_error("config: Events group '%s' is empty", events_group->name);
             return -1;

src/config_cli.c

@@ -329,14 +329,14 @@ config_setup_from_cli(int argc, char **argv, struct config *config)
             if (setup_global_events_group(config, optarg)) {
                 return -1;
             }
-            current_events_group = zhashx_lookup(config->events.system, optarg);
+            current_events_group = (struct events_group *) zhashx_lookup(config->events.system, optarg);
             break;
 
             case 'c':
             if (setup_cgroups_events_group(config, optarg)) {
                 return -1;
             }
-            current_events_group = zhashx_lookup(config->events.containers, optarg);
+            current_events_group = (struct events_group *) zhashx_lookup(config->events.containers, optarg);
             break;
 
             case 'o':

src/config_json.c

@@ -469,7 +469,7 @@ static int
 parse_json_configuration_file_from_fd(int fd, json_object **obj)
 {
     int ret = -1;
-    char buffer[JSON_FILE_BUFFER_SIZE] = {0};
+    char buffer[JSON_FILE_BUFFER_SIZE] = {};
     json_tokener *tok = NULL;
     enum json_tokener_error jerr;
     size_t line, column;

src/events.c

@@ -99,7 +99,7 @@ get_msr_pmu_event_encoding(const char *event_name, struct perf_event_attr *attr)
 static int
 setup_perf_event_attr(const char *event_name, struct perf_event_attr *attr)
 {
-    pfm_perf_encode_arg_t arg = {0};
+    pfm_perf_encode_arg_t arg = {};
 
     attr->size = sizeof(struct perf_event_attr);
     attr->disabled = 1;
@@ -120,11 +120,11 @@ setup_perf_event_attr(const char *event_name, struct perf_event_attr *attr)
 struct event_config *
 event_config_create(const char *event_name)
 {
-    struct perf_event_attr attr = {0};
+    struct perf_event_attr attr = {};
     struct event_config *config = NULL;
 
     if (!setup_perf_event_attr(event_name, &attr)) {
-        config = malloc(sizeof(struct event_config));
+        config = (struct event_config *) malloc(sizeof(struct event_config));
         if (config) {
             snprintf(config->name, NAME_MAX, "%s", event_name);
             config->attr = attr;
@@ -140,7 +140,7 @@ event_config_dup(struct event_config *config)
     struct event_config *copy = NULL;
 
     if (config) {
-        copy = malloc(sizeof(struct event_config));
+        copy = (struct event_config *) malloc(sizeof(struct event_config));
         if (copy) {
             snprintf(copy->name, NAME_MAX, "%s", config->name);
             copy->attr = config->attr;
@@ -162,7 +162,7 @@ event_config_destroy(struct event_config **config)
 struct events_group *
 events_group_create(const char *name)
 {
-    struct events_group *group = malloc(sizeof(struct events_group));
+    struct events_group *group = (struct events_group *) malloc(sizeof(struct events_group));
 
     if (group) {
         snprintf(group->name, NAME_MAX, "%s", name);
@@ -182,7 +182,7 @@ events_group_dup(struct events_group *group)
     struct events_group *copy = NULL;
 
     if (group) {
-        copy = malloc(sizeof(struct events_group));
+        copy = (struct events_group *) malloc(sizeof(struct events_group));
         if (copy) {
             snprintf(copy->name, NAME_MAX, "%s", group->name);
             copy->type = group->type;

src/hwinfo.c

@@ -52,7 +52,7 @@
 static struct hwinfo_pkg *
 hwinfo_pkg_create(void)
 {
-    struct hwinfo_pkg *pkg = malloc(sizeof(struct hwinfo_pkg));
+    struct hwinfo_pkg *pkg = (struct hwinfo_pkg *) malloc(sizeof(struct hwinfo_pkg));
 
     if (!pkg)
         return NULL;
@@ -67,7 +67,7 @@ hwinfo_pkg_create(void)
 static struct hwinfo_pkg *
 hwinfo_pkg_dup(struct hwinfo_pkg *pkg)
 {
-    struct hwinfo_pkg *pkgcpy = malloc(sizeof(struct hwinfo_pkg));
+    struct hwinfo_pkg *pkgcpy = (struct hwinfo_pkg *) malloc(sizeof(struct hwinfo_pkg));
 
     if (!pkgcpy)
         return NULL;
@@ -92,7 +92,7 @@ static int
 get_cpu_online_status(const char *cpu_dir)
 {
     int status = 1;
-    char path[PATH_MAX] = {0};
+    char path[PATH_MAX] = {};
     FILE *f = NULL;
     char buffer[2]; /* boolean expected */
 
@@ -118,7 +118,7 @@ static char *
 get_package_id(const char *cpu_dir)
 {
     FILE *f = NULL;
-    char path[PATH_MAX] = {0};
+    char path[PATH_MAX] = {};
     char buffer[24]; /* log10(ULLONG_MAX) */
     char *id = NULL;
 
@@ -138,7 +138,7 @@ get_package_id(const char *cpu_dir)
 static char *
 parse_cpu_id_from_name(const char *str)
 {
-    regex_t re = {0};
+    regex_t re = {};
     regmatch_t matches[CPU_ID_REGEX_EXPECTED_MATCHES];
     char *id = NULL;
 
@@ -191,7 +191,7 @@ do_packages_detection(struct hwinfo *hwinfo)
             }
 
             /* get cpu pkg or create it if never encountered */
-            pkg = zhashx_lookup(hwinfo->pkgs, pkg_id);
+            pkg = (struct hwinfo_pkg *) zhashx_lookup(hwinfo->pkgs, pkg_id);
             if (!pkg) {
                 pkg = hwinfo_pkg_create();
                 if (!pkg) {
@@ -201,7 +201,7 @@ do_packages_detection(struct hwinfo *hwinfo)
 
                 zhashx_insert(hwinfo->pkgs, pkg_id, pkg);
                 hwinfo_pkg_destroy(&pkg);
-                pkg = zhashx_lookup(hwinfo->pkgs, pkg_id); /* get the copy the pkg done by zhashx_insert */
+                pkg = (struct hwinfo_pkg *) zhashx_lookup(hwinfo->pkgs, pkg_id); /* get the copy the pkg done by zhashx_insert */
             }
 
             zlistx_add_end(pkg->cpus_id, cpu_id);
@@ -235,7 +235,7 @@ hwinfo_detect(struct hwinfo *hwinfo)
 struct hwinfo *
 hwinfo_create(void)
 {
-    struct hwinfo *hw = malloc(sizeof(struct hwinfo));
+    struct hwinfo *hw = (struct hwinfo *) malloc(sizeof(struct hwinfo));
 
     if (!hw)
         return NULL;
@@ -250,7 +250,7 @@ hwinfo_create(void)
 struct hwinfo *
 hwinfo_dup(struct hwinfo *hwinfo)
 {
-    struct hwinfo *hwinfocpy = malloc(sizeof(struct hwinfo));
+    struct hwinfo *hwinfocpy = (struct hwinfo *) malloc(sizeof(struct hwinfo));
 
     if (!hwinfocpy)
         return NULL;

src/payload.c

@@ -38,7 +38,7 @@
 struct payload_cpu_data *
 payload_cpu_data_create(void)
 {
-    struct payload_cpu_data *data = malloc(sizeof(struct payload_cpu_data));
+    struct payload_cpu_data *data = (struct payload_cpu_data *) malloc(sizeof(struct payload_cpu_data));
 
     if (!data)
         return NULL;
@@ -64,7 +64,7 @@ payload_cpu_data_destroy(struct payload_cpu_data **data_ptr)
 struct payload_pkg_data *
 payload_pkg_data_create(void)
 {
-    struct payload_pkg_data *data = malloc(sizeof(struct payload_pkg_data));
+    struct payload_pkg_data *data = (struct payload_pkg_data *) malloc(sizeof(struct payload_pkg_data));
 
     if (!data)
         return NULL;
@@ -89,7 +89,7 @@ payload_pkg_data_destroy(struct payload_pkg_data **data_ptr)
 struct payload_group_data *
 payload_group_data_create(void)
 {
-    struct payload_group_data *data = malloc(sizeof(struct payload_group_data));
+    struct payload_group_data *data = (struct payload_group_data *) malloc(sizeof(struct payload_group_data));
 
     if (!data)
         return NULL;
@@ -114,7 +114,7 @@ payload_group_data_destroy(struct payload_group_data **data_ptr)
 struct payload *
 payload_create(uint64_t timestamp, const char *target_name)
 {
-    struct payload *payload = malloc(sizeof(struct payload));
+    struct payload *payload = (struct payload *) malloc(sizeof(struct payload));
 
     if (!payload)
         return NULL;