Silence Clang-Tidy

This commit makes lots of changes to the C code to appease the
Clang-Tidy linter. Some of the less obvious ones are due to C's weird
semantics regarding handling of numeric literals.

We also disable a bunch of the detections because they are
super-pedantic, arguably useless, or we have our own unwritten coding
style rules that solve the issues.

4 files changed, 26 insertions, 19 deletions

diff --git a/utils/cache_gc/categories.c b/utils/cache_gc/categories.c
index 19dec45c..aaa1ae53 100644
--- a/utils/cache_gc/categories.c
+++ b/utils/cache_gc/categories.c
@@ -18,7 +18,7 @@ static bool rrtype_is_infrastructure(uint16_t r)
 	}
 }
 
-static int get_random(int to)
+static unsigned int get_random(int to)
 {
 	// We don't need these to be really unpredictable,
 	// but this should be cheap enough not to be noticeable.
diff --git a/utils/cache_gc/db.c b/utils/cache_gc/db.c
index fc4a2fdb..c31ff220 100644
--- a/utils/cache_gc/db.c
+++ b/utils/cache_gc/db.c
@@ -9,11 +9,13 @@
 #include <time.h>
 #include <sys/stat.h>
 
+#define MDB_FILE "/data.mdb"
+
 int kr_gc_cache_open(const char *cache_path, struct kr_cache *kres_db,
 		     knot_db_t ** libknot_db)
 {
-	char cache_data[strlen(cache_path) + 10];
-	snprintf(cache_data, sizeof(cache_data), "%s/data.mdb", cache_path);
+	char cache_data[strlen(cache_path) + sizeof(MDB_FILE)];
+	(void)snprintf(cache_data, sizeof(cache_data), "%s" MDB_FILE, cache_path);
 
 	struct stat st = { 0 };
 	if (stat(cache_path, &st) || !(st.st_mode & S_IFDIR)
diff --git a/utils/cache_gc/kr_cache_gc.c b/utils/cache_gc/kr_cache_gc.c
index 5978345c..62465f51 100644
--- a/utils/cache_gc/kr_cache_gc.c
+++ b/utils/cache_gc/kr_cache_gc.c
@@ -194,12 +194,12 @@ int kr_cache_gc(kr_cache_gc_cfg_t *cfg, kr_cache_gc_state_t **state)
 	// Mixing ^^ page usage and entry sizes (key+value lengths) didn't work
 	// too well, probably due to internal fragmentation after some GC cycles.
 	// Therefore let's scale this by the ratio of these two sums.
-	ssize_t cats_sumsize = 0;
+	size_t cats_sumsize = 0;
 	for (int i = 0; i < CATEGORIES; ++i) {
 		cats_sumsize += cats.categories_sizes[i];
 	}
 	/* use less precise variant to avoid 32-bit overflow */
-	ssize_t amount_tofree = cats_sumsize / 100 * cfg->cache_to_be_freed;
+	size_t amount_tofree = cats_sumsize / 100 * cfg->cache_to_be_freed;
 
 	kr_log_debug(CACHE, "tofree: %zd / %zd\n", amount_tofree, cats_sumsize);
 	if (VERBOSE_STATUS) {
@@ -212,8 +212,11 @@ int kr_cache_gc(kr_cache_gc_cfg_t *cfg, kr_cache_gc_state_t **state)
 	}
 
 	category_t limit_category = CATEGORIES;
-	while (limit_category > 0 && amount_tofree > 0) {
-		amount_tofree -= cats.categories_sizes[--limit_category];
+	while (limit_category > 0) {
+		size_t cat_size = cats.categories_sizes[--limit_category];
+		if (cat_size > amount_tofree)
+			break;
+		amount_tofree -= cat_size;
 	}
 
 	printf("Cache analyzed in %.0lf msecs, %zu records, limit category is %d.\n",
diff --git a/utils/cache_gc/main.c b/utils/cache_gc/main.c
index 5adf19f0..fe131cd0 100644
--- a/utils/cache_gc/main.c
+++ b/utils/cache_gc/main.c
@@ -13,6 +13,7 @@
 #include "kr_cache_gc.h"
 
 static volatile int killed = 0;
+static volatile int exit_code = 0;
 
 static void got_killed(int signum)
 {
@@ -21,12 +22,10 @@ static void got_killed(int signum)
 	case 1:
 		break;
 	case 2:
-		exit(5);
+		exit_code = 5;
 		break;
-	case 3:
-		abort();
 	default:
-		kr_assert(false);
+		abort();
 	}
 }
 
@@ -60,16 +59,20 @@ int main(int argc, char *argv[])
 {
 	printf("Knot Resolver Cache Garbage Collector, version %s\n", PACKAGE_VERSION);
 	if (setvbuf(stdout, NULL, _IONBF, 0) || setvbuf(stderr, NULL, _IONBF, 0)) {
-		fprintf(stderr, "Failed to to set output buffering (ignored): %s\n",
+		(void)fprintf(stderr, "Failed to to set output buffering (ignored): %s\n",
 				strerror(errno));
-		fflush(stderr);
+		(void)fflush(stderr);
 	}
 
-	signal(SIGTERM, got_killed);
-	signal(SIGKILL, got_killed);
-	signal(SIGPIPE, got_killed);
-	signal(SIGCHLD, got_killed);
-	signal(SIGINT, got_killed);
+	struct sigaction act = {
+		.sa_handler = got_killed,
+		.sa_flags = SA_RESETHAND,
+	};
+	sigemptyset(&act.sa_mask);
+	kr_assert(!sigaction(SIGTERM, &act, NULL));
+	kr_assert(!sigaction(SIGPIPE, &act, NULL));
+	kr_assert(!sigaction(SIGCHLD, &act, NULL));
+	kr_assert(!sigaction(SIGINT, &act, NULL));
 
 	kr_cache_gc_cfg_t cfg = {
 		.ro_txn_items = 200,
@@ -131,7 +134,6 @@ int main(int argc, char *argv[])
 		return 1;
 	}
 
-	int exit_code = 0;
 	kr_cache_gc_state_t *gc_state = NULL;
 	bool last_espace = false;
 	do {