tree-wide: add DEBUG_LOGGING macro that checks whether debug logging is on (#7645)

This makes things a bit easier to read I think, and also makes sure we
always use the _unlikely_ wrapper around it, which so far we used
sometimes and other times we didn't. Let's clean that up.

coccinelle/debug-logging.cocci

@@ -0,0 +1,8 @@
+@@
+@@
+- _unlikely_(log_get_max_level() >= LOG_DEBUG)
++ DEBUG_LOGGING
+@@
+@@
+- log_get_max_level() >= LOG_DEBUG
++ DEBUG_LOGGING

src/analyze/analyze-verify.c

@@ -220,7 +220,7 @@ static int verify_unit(Unit *u, bool check_man) {
 
         assert(u);
 
-        if (log_get_max_level() >= LOG_DEBUG)
+        if (DEBUG_LOGGING)
                 unit_dump(u, stdout, "\t");
 
         log_unit_debug(u, "Creating %s/start job", u->id);

src/basic/log.h

@@ -335,3 +335,5 @@ int log_syntax_internal(
                                             "String is not UTF-8 clean, ignoring assignment: %s", strna(_p)); \
                 }                                                       \
         })
+
+#define DEBUG_LOGGING _unlikely_(log_get_max_level() >= LOG_DEBUG)

src/core/execute.c

@@ -3418,7 +3418,7 @@ static int exec_child(
                 return log_oom();
         }
 
-        if (_unlikely_(log_get_max_level() >= LOG_DEBUG)) {
+        if (DEBUG_LOGGING) {
                 _cleanup_free_ char *line;
 
                 line = exec_command_line(final_argv);

src/core/manager.c

@@ -1887,7 +1887,7 @@ static void manager_invoke_notify_message(Manager *m, Unit *u, pid_t pid, const
 
         if (UNIT_VTABLE(u)->notify_message)
                 UNIT_VTABLE(u)->notify_message(u, pid, tags, fds);
-        else if (_unlikely_(log_get_max_level() >= LOG_DEBUG)) {
+        else if (DEBUG_LOGGING) {
                 _cleanup_free_ char *x = NULL, *y = NULL;
 
                 x = cescape(buf);

src/core/service.c

@@ -3417,7 +3417,7 @@ static void service_notify_message(Unit *u, pid_t pid, char **tags, FDSet *fds)
         if (!service_notify_message_authorized(SERVICE(u), pid, tags, fds))
                 return;
 
-        if (log_get_max_level() >= LOG_DEBUG) {
+        if (DEBUG_LOGGING) {
                 _cleanup_free_ char *cc = NULL;
 
                 cc = strv_join(tags, ", ");

src/coredump/coredumpctl.c

@@ -1061,7 +1061,7 @@ int main(int argc, char *argv[]) {
         if (r < 0)
                 goto end;
 
-        if (_unlikely_(log_get_max_level() >= LOG_DEBUG)) {
+        if (DEBUG_LOGGING) {
                 _cleanup_free_ char *filter;
 
                 filter = journal_make_match_string(j);

src/journal-remote/journal-upload.c

@@ -248,7 +248,7 @@ int start_upload(Uploader *u,
                 easy_setopt(curl, CURLOPT_HTTPHEADER, u->header,
                             LOG_ERR, return -EXFULL);
 
-                if (_unlikely_(log_get_max_level() >= LOG_DEBUG))
+                if (DEBUG_LOGGING)
                         /* enable verbose for easier tracing */
                         easy_setopt(curl, CURLOPT_VERBOSE, 1L, LOG_WARNING, );
 

src/journal/journalctl.c

@@ -2257,7 +2257,7 @@ int main(int argc, char *argv[]) {
         if (r < 0)
                 goto finish;
 
-        if (_unlikely_(log_get_max_level() >= LOG_DEBUG)) {
+        if (DEBUG_LOGGING) {
                 _cleanup_free_ char *filter;
 
                 filter = journal_make_match_string(j);

src/resolve/resolved-dns-cache.c

@@ -476,7 +476,7 @@ static int dns_cache_put_positive(
         if (r < 0)
                 return r;
 
-        if (log_get_max_level() >= LOG_DEBUG) {
+        if (DEBUG_LOGGING) {
                 _cleanup_free_ char *t = NULL;
 
                 (void) in_addr_to_string(i->owner_family, &i->owner_address, &t);

src/resolve/resolved-manager.c

@@ -1410,7 +1410,7 @@ void manager_dnssec_verdict(Manager *m, DnssecVerdict verdict, const DnsResource
         assert(verdict >= 0);
         assert(verdict < _DNSSEC_VERDICT_MAX);
 
-        if (log_get_max_level() >= LOG_DEBUG) {
+        if (DEBUG_LOGGING) {
                 char s[DNS_RESOURCE_KEY_STRING_MAX];
 
                 log_debug("Found verdict for lookup %s: %s",

src/shared/logs-show.c

@@ -1392,7 +1392,7 @@ int show_journal_by_unit(
         if (r < 0)
                 return log_error_errno(r, "Failed to add unit matches: %m");
 
-        if (_unlikely_(log_get_max_level() >= LOG_DEBUG)) {
+        if (DEBUG_LOGGING) {
                 _cleanup_free_ char *filter;
 
                 filter = journal_make_match_string(j);

src/shared/seccomp-util.c

@@ -954,7 +954,7 @@ int seccomp_restrict_namespaces(unsigned long retain) {
         uint32_t arch;
         int r;
 
-        if (log_get_max_level() >= LOG_DEBUG) {
+        if (DEBUG_LOGGING) {
                 _cleanup_free_ char *s = NULL;
 
                 (void) namespace_flag_to_string_many(retain, &s);