[PATCH bpf-next v3 1/2] tools/resolve_btfids: Add --fatal_warnings option

["Thomas Weißschuh" <linux@weissschuh.net>]

Currently warnings emitted by resolve_btfids are buried in the build log
and are slipping into mainline frequently.
Add an option to elevate warnings to hard errors so the CI bots can
catch any new warnings.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
---
 tools/bpf/resolve_btfids/main.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/tools/bpf/resolve_btfids/main.c b/tools/bpf/resolve_btfids/main.c
index bd9f960bce3d5b74dc34159b35af1e0b33524d2d..d47191c6e55e10215269774f4bdfc6e5b4bf72f8 100644
--- a/tools/bpf/resolve_btfids/main.c
+++ b/tools/bpf/resolve_btfids/main.c
@@ -141,6 +141,7 @@ struct object {
 };
 
 static int verbose;
+static int warnings;
 
 static int eprintf(int level, int var, const char *fmt, ...)
 {
@@ -604,6 +605,7 @@ static int symbols_resolve(struct object *obj)
 			if (id->id) {
 				pr_info("WARN: multiple IDs found for '%s': %d, %d - using %d\n",
 					str, id->id, type_id, id->id);
+				warnings++;
 			} else {
 				id->id = type_id;
 				(*nr)--;
@@ -625,8 +627,10 @@ static int id_patch(struct object *obj, struct btf_id *id)
 	int i;
 
 	/* For set, set8, id->id may be 0 */
-	if (!id->id && !id->is_set && !id->is_set8)
+	if (!id->id && !id->is_set && !id->is_set8) {
 		pr_err("WARN: resolve_btfids: unresolved symbol %s\n", id->name);
+		warnings++;
+	}
 
 	for (i = 0; i < id->addr_cnt; i++) {
 		unsigned long addr = id->addr[i];
@@ -782,6 +786,7 @@ int main(int argc, const char **argv)
 		.funcs    = RB_ROOT,
 		.sets     = RB_ROOT,
 	};
+	bool fatal_warnings = false;
 	struct option btfid_options[] = {
 		OPT_INCR('v', "verbose", &verbose,
 			 "be more verbose (show errors, etc)"),
@@ -789,6 +794,8 @@ int main(int argc, const char **argv)
 			   "BTF data"),
 		OPT_STRING('b', "btf_base", &obj.base_btf_path, "file",
 			   "path of file providing base BTF"),
+		OPT_BOOLEAN(0, "fatal_warnings", &fatal_warnings,
+			    "turn warnings into errors"),
 		OPT_END()
 	};
 	int err = -1;
@@ -823,7 +830,8 @@ int main(int argc, const char **argv)
 	if (symbols_patch(&obj))
 		goto out;
 
-	err = 0;
+	if (!(fatal_warnings && warnings))
+		err = 0;
 out:
 	if (obj.efile.elf) {
 		elf_end(obj.efile.elf);

-- 
2.47.1