perf env: Introduce perf_env__arch_strerrno()

That will cache the arch specific function translating error numbers to
strings.
Reviewed-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Laight <David.Laight@ACULAB.COM>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/20231201203046.486596-2-acme@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-trace.c

@@ -2470,9 +2470,8 @@ static int trace__fprintf_callchain(struct trace *trace, struct perf_sample *sam
 static const char *errno_to_name(struct evsel *evsel, int err)
 {
 	struct perf_env *env = evsel__env(evsel);
-	const char *arch_name = perf_env__arch(env);
 
-	return arch_syscalls__strerrno(arch_name, err);
+	return perf_env__arch_strerrno(env, err);
 }
 
 static int trace__sys_exit(struct trace *trace, struct evsel *evsel,
@@ -4264,12 +4263,11 @@ static size_t thread__dump_stats(struct thread_trace *ttrace,
 			printed += fprintf(fp, " %9.3f %9.2f%%\n", max, pct);
 
 			if (trace->errno_summary && stats->nr_failures) {
-				const char *arch_name = perf_env__arch(trace->host->env);
 				int e;
 
 				for (e = 0; e < stats->max_errno; ++e) {
 					if (stats->errnos[e] != 0)
-						fprintf(fp, "\t\t\t\t%s: %d\n", arch_syscalls__strerrno(arch_name, e + 1), stats->errnos[e]);
+						fprintf(fp, "\t\t\t\t%s: %d\n", perf_env__arch_strerrno(trace->host->env, e + 1), stats->errnos[e]);
 				}
 			}
 		}

tools/perf/util/env.c

@@ -3,6 +3,7 @@
 #include "debug.h"
 #include "env.h"
 #include "util/header.h"
+#include "linux/compiler.h"
 #include <linux/ctype.h>
 #include <linux/zalloc.h>
 #include "cgroup.h"
@@ -12,6 +13,7 @@
 #include <string.h>
 #include "pmus.h"
 #include "strbuf.h"
+#include "trace/beauty/beauty.h"
 
 struct perf_env perf_env;
 
@@ -453,6 +455,16 @@ const char *perf_env__arch(struct perf_env *env)
 	return normalize_arch(arch_name);
 }
 
+const char *perf_env__arch_strerrno(struct perf_env *env __maybe_unused, int err __maybe_unused)
+{
+#if defined(HAVE_SYSCALL_TABLE_SUPPORT) && defined(HAVE_LIBTRACEEVENT)
+	const char *arch_name = perf_env__arch(env);
+	return arch_syscalls__strerrno(arch_name, err);
+#else
+	return "!(HAVE_SYSCALL_TABLE_SUPPORT && HAVE_LIBTRACEEVENT)";
+#endif
+}
+
 const char *perf_env__cpuid(struct perf_env *env)
 {
 	int status;

tools/perf/util/env.h

@@ -164,6 +164,7 @@ int perf_env__read_cpu_topology_map(struct perf_env *env);
 void cpu_cache_level__free(struct cpu_cache_level *cache);
 
 const char *perf_env__arch(struct perf_env *env);
+const char *perf_env__arch_strerrno(struct perf_env *env, int err);
 const char *perf_env__cpuid(struct perf_env *env);
 const char *perf_env__raw_arch(struct perf_env *env);
 int perf_env__nr_cpus_avail(struct perf_env *env);