2 files changed, 47 insertions, 0 deletions

diff --git a/tools/perf/util/llvm-utils.c b/tools/perf/util/llvm-utils.c
index 33071d6159bc..878a566763c3 100644
--- a/tools/perf/util/llvm-utils.c
+++ b/tools/perf/util/llvm-utils.c
@@ -42,6 +42,8 @@ int perf_llvm_config(const char *var, const char *value)
                 llvm_param.kbuild_dir = strdup(value);
         else if (!strcmp(var, "kbuild-opts"))
                 llvm_param.kbuild_opts = strdup(value);
+        else if (!strcmp(var, "dump-obj"))
+                llvm_param.dump_obj = !!perf_config_bool(var, value);
         else
                 return -1;
         llvm_param.user_set_param = true;
@@ -326,6 +328,42 @@ get_kbuild_opts(char **kbuild_dir, char **kbuild_include_opts)
         pr_debug("include option is set to %s\n", *kbuild_include_opts);
 }
 
+static void
+dump_obj(const char *path, void *obj_buf, size_t size)
+{
+        char *obj_path = strdup(path);
+        FILE *fp;
+        char *p;
+
+        if (!obj_path) {
+                pr_warning("WARNING: No enough memory, skip object dumping\n");
+                return;
+        }
+
+        p = strrchr(obj_path, '.');
+        if (!p || (strcmp(p, ".c") != 0)) {
+                pr_warning("WARNING: invalid llvm source path: '%s', skip object dumping\n",
+                           obj_path);
+                goto out;
+        }
+
+        p[1] = 'o';
+        fp = fopen(obj_path, "wb");
+        if (!fp) {
+                pr_warning("WARNING: failed to open '%s': %s, skip object dumping\n",
+                           obj_path, strerror(errno));
+                goto out;
+        }
+
+        pr_info("LLVM: dumping %s\n", obj_path);
+        if (fwrite(obj_buf, size, 1, fp) != 1)
+                pr_warning("WARNING: failed to write to file '%s': %s, skip object dumping\n",
+                           obj_path, strerror(errno));
+        fclose(fp);
+out:
+        free(obj_path);
+}
+
 int llvm__compile_bpf(const char *path, void **p_obj_buf,
                       size_t *p_obj_buf_sz)
 {
@@ -411,6 +449,10 @@ int llvm__compile_bpf(const char *path, void **p_obj_buf,
 
         free(kbuild_dir);
         free(kbuild_include_opts);
+
+        if (llvm_param.dump_obj)
+                dump_obj(path, obj_buf, obj_buf_sz);
+
         if (!p_obj_buf)
                 free(obj_buf);
         else
diff --git a/tools/perf/util/llvm-utils.h b/tools/perf/util/llvm-utils.h
index 23b9a743fe72..9f501cef06a1 100644
--- a/tools/perf/util/llvm-utils.h
+++ b/tools/perf/util/llvm-utils.h
@@ -30,6 +30,11 @@ struct llvm_param {
          */
         const char *kbuild_opts;
         /*
+         * Default is false. If set to true, write compiling result
+         * to object file.
+         */
+        bool dump_obj;
+        /*
          * Default is false. If one of the above fields is set by user
          * explicitly then user_set_llvm is set to true. This is used
          * for perf test. If user doesn't set anything in .perfconfig