perf tools: Refactor LLVM test warning for missing binary

The same warning is duplicated in two places so refactor it into a
single function "search_program_and_warn". This will be used a third
time in a later commit.
Signed-off-by: NJames Clark <james.clark@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: clang-built-linux@googlegroups.com
Link: http://lore.kernel.org/lkml/20210831145501.2135754-1-james.clark@arm.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/llvm-utils.c

@@ -38,6 +38,8 @@ struct llvm_param llvm_param = {
 	.user_set_param = false,
 };
 
+static void version_notice(void);
+
 int perf_llvm_config(const char *var, const char *value)
 {
 	if (!strstarts(var, "llvm."))
@@ -108,6 +110,21 @@ search_program(const char *def, const char *name,
 	return ret;
 }
 
+static int search_program_and_warn(const char *def, const char *name,
+				   char *output)
+{
+	int ret = search_program(def, name, output);
+
+	if (ret) {
+		pr_err("ERROR:\tunable to find %s.\n"
+		       "Hint:\tTry to install latest clang/llvm to support BPF. Check your $PATH\n"
+		       "     \tand '%s-path' option in [llvm] section of ~/.perfconfig.\n",
+		       name, name);
+		version_notice();
+	}
+	return ret;
+}
+
 #define READ_SIZE	4096
 static int
 read_from_pipe(const char *cmd, void **p_buf, size_t *p_read_sz)
@@ -458,16 +475,10 @@ int llvm__compile_bpf(const char *path, void **p_obj_buf,
 	if (!template)
 		template = CLANG_BPF_CMD_DEFAULT_TEMPLATE;
 
-	err = search_program(llvm_param.clang_path,
+	err = search_program_and_warn(llvm_param.clang_path,
 			     "clang", clang_path);
-	if (err) {
-		pr_err(
-"ERROR:\tunable to find clang.\n"
-"Hint:\tTry to install latest clang/llvm to support BPF. Check your $PATH\n"
-"     \tand 'clang-path' option in [llvm] section of ~/.perfconfig.\n");
-		version_notice();
+	if (err)
 		return -ENOENT;
-	}
 
 	/*
 	 * This is an optional work. Even it fail we can continue our
@@ -495,14 +506,9 @@ int llvm__compile_bpf(const char *path, void **p_obj_buf,
 	force_set_env("WORKING_DIR", kbuild_dir ? : ".");
 
 	if (opts) {
-		err = search_program(llvm_param.llc_path, "llc", llc_path);
-		if (err) {
-			pr_err("ERROR:\tunable to find llc.\n"
-			       "Hint:\tTry to install latest clang/llvm to support BPF. Check your $PATH\n"
-			       "     \tand 'llc-path' option in [llvm] section of ~/.perfconfig.\n");
-			version_notice();
+		err = search_program_and_warn(llvm_param.llc_path, "llc", llc_path);
+		if (err)
 			goto errout;
-		}
 
 		err = -ENOMEM;
 		if (asprintf(&pipe_template, "%s -emit-llvm | %s -march=bpf %s -filetype=obj -o -",