[PATCH bpf-next v10 13/13] btf: Refactor the code by calling str_is_empty

[Donglin Peng <dolinux.peng@gmail.com>]

From: pengdonglin <pengdonglin@xiaomi.com>

Calling the str_is_empty function to clarify the code and
no functional changes are introduced.

Cc: Eduard Zingerman <eddyz87@gmail.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Ihor Solodrai <ihor.solodrai@linux.dev>
Cc: Xiaoqin Zhang <zhangxiaoqin@xiaomi.com>
Signed-off-by: pengdonglin <pengdonglin@xiaomi.com>
---
 tools/lib/bpf/btf.c    | 34 +++++++++++++++++-----------------
 tools/lib/bpf/libbpf.c |  4 ++--
 2 files changed, 19 insertions(+), 19 deletions(-)

diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 571b72bd90b5..013b1e5d396d 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -2169,7 +2169,7 @@ int btf__add_int(struct btf *btf, const char *name, size_t byte_sz, int encoding
 	int sz, name_off;
 
 	/* non-empty name */
-	if (!name || !name[0])
+	if (str_is_empty(name))
 		return libbpf_err(-EINVAL);
 	/* byte_sz must be power of 2 */
 	if (!byte_sz || (byte_sz & (byte_sz - 1)) || byte_sz > 16)
@@ -2217,7 +2217,7 @@ int btf__add_float(struct btf *btf, const char *name, size_t byte_sz)
 	int sz, name_off;
 
 	/* non-empty name */
-	if (!name || !name[0])
+	if (str_is_empty(name))
 		return libbpf_err(-EINVAL);
 
 	/* byte_sz must be one of the explicitly allowed values */
@@ -2272,7 +2272,7 @@ static int btf_add_ref_kind(struct btf *btf, int kind, const char *name, int ref
 	if (!t)
 		return libbpf_err(-ENOMEM);
 
-	if (name && name[0]) {
+	if (!str_is_empty(name)) {
 		name_off = btf__add_str(btf, name);
 		if (name_off < 0)
 			return name_off;
@@ -2349,7 +2349,7 @@ static int btf_add_composite(struct btf *btf, int kind, const char *name, __u32
 	if (!t)
 		return libbpf_err(-ENOMEM);
 
-	if (name && name[0]) {
+	if (!str_is_empty(name)) {
 		name_off = btf__add_str(btf, name);
 		if (name_off < 0)
 			return name_off;
@@ -2450,7 +2450,7 @@ int btf__add_field(struct btf *btf, const char *name, int type_id,
 	if (!m)
 		return libbpf_err(-ENOMEM);
 
-	if (name && name[0]) {
+	if (!str_is_empty(name)) {
 		name_off = btf__add_str(btf, name);
 		if (name_off < 0)
 			return name_off;
@@ -2488,7 +2488,7 @@ static int btf_add_enum_common(struct btf *btf, const char *name, __u32 byte_sz,
 	if (!t)
 		return libbpf_err(-ENOMEM);
 
-	if (name && name[0]) {
+	if (!str_is_empty(name)) {
 		name_off = btf__add_str(btf, name);
 		if (name_off < 0)
 			return name_off;
@@ -2546,7 +2546,7 @@ int btf__add_enum_value(struct btf *btf, const char *name, __s64 value)
 		return libbpf_err(-EINVAL);
 
 	/* non-empty name */
-	if (!name || !name[0])
+	if (str_is_empty(name))
 		return libbpf_err(-EINVAL);
 	if (value < INT_MIN || value > UINT_MAX)
 		return libbpf_err(-E2BIG);
@@ -2623,7 +2623,7 @@ int btf__add_enum64_value(struct btf *btf, const char *name, __u64 value)
 		return libbpf_err(-EINVAL);
 
 	/* non-empty name */
-	if (!name || !name[0])
+	if (str_is_empty(name))
 		return libbpf_err(-EINVAL);
 
 	/* decompose and invalidate raw data */
@@ -2663,7 +2663,7 @@ int btf__add_enum64_value(struct btf *btf, const char *name, __u64 value)
  */
 int btf__add_fwd(struct btf *btf, const char *name, enum btf_fwd_kind fwd_kind)
 {
-	if (!name || !name[0])
+	if (str_is_empty(name))
 		return libbpf_err(-EINVAL);
 
 	switch (fwd_kind) {
@@ -2699,7 +2699,7 @@ int btf__add_fwd(struct btf *btf, const char *name, enum btf_fwd_kind fwd_kind)
  */
 int btf__add_typedef(struct btf *btf, const char *name, int ref_type_id)
 {
-	if (!name || !name[0])
+	if (str_is_empty(name))
 		return libbpf_err(-EINVAL);
 
 	return btf_add_ref_kind(btf, BTF_KIND_TYPEDEF, name, ref_type_id, 0);
@@ -2751,7 +2751,7 @@ int btf__add_restrict(struct btf *btf, int ref_type_id)
  */
 int btf__add_type_tag(struct btf *btf, const char *value, int ref_type_id)
 {
-	if (!value || !value[0])
+	if (str_is_empty(value))
 		return libbpf_err(-EINVAL);
 
 	return btf_add_ref_kind(btf, BTF_KIND_TYPE_TAG, value, ref_type_id, 0);
@@ -2768,7 +2768,7 @@ int btf__add_type_tag(struct btf *btf, const char *value, int ref_type_id)
  */
 int btf__add_type_attr(struct btf *btf, const char *value, int ref_type_id)
 {
-	if (!value || !value[0])
+	if (str_is_empty(value))
 		return libbpf_err(-EINVAL);
 
 	return btf_add_ref_kind(btf, BTF_KIND_TYPE_TAG, value, ref_type_id, 1);
@@ -2787,7 +2787,7 @@ int btf__add_func(struct btf *btf, const char *name,
 {
 	int id;
 
-	if (!name || !name[0])
+	if (str_is_empty(name))
 		return libbpf_err(-EINVAL);
 	if (linkage != BTF_FUNC_STATIC && linkage != BTF_FUNC_GLOBAL &&
 	    linkage != BTF_FUNC_EXTERN)
@@ -2873,7 +2873,7 @@ int btf__add_func_param(struct btf *btf, const char *name, int type_id)
 	if (!p)
 		return libbpf_err(-ENOMEM);
 
-	if (name && name[0]) {
+	if (!str_is_empty(name)) {
 		name_off = btf__add_str(btf, name);
 		if (name_off < 0)
 			return name_off;
@@ -2908,7 +2908,7 @@ int btf__add_var(struct btf *btf, const char *name, int linkage, int type_id)
 	int sz, name_off;
 
 	/* non-empty name */
-	if (!name || !name[0])
+	if (str_is_empty(name))
 		return libbpf_err(-EINVAL);
 	if (linkage != BTF_VAR_STATIC && linkage != BTF_VAR_GLOBAL_ALLOCATED &&
 	    linkage != BTF_VAR_GLOBAL_EXTERN)
@@ -2957,7 +2957,7 @@ int btf__add_datasec(struct btf *btf, const char *name, __u32 byte_sz)
 	int sz, name_off;
 
 	/* non-empty name */
-	if (!name || !name[0])
+	if (str_is_empty(name))
 		return libbpf_err(-EINVAL);
 
 	if (btf_ensure_modifiable(btf))
@@ -3034,7 +3034,7 @@ static int btf_add_decl_tag(struct btf *btf, const char *value, int ref_type_id,
 	struct btf_type *t;
 	int sz, value_off;
 
-	if (!value || !value[0] || component_idx < -1)
+	if (str_is_empty(value) || component_idx < -1)
 		return libbpf_err(-EINVAL);
 
 	if (validate_type_id(ref_type_id))
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 1a52d818a76c..96c6db972855 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -2904,7 +2904,7 @@ static int bpf_object__init_user_btf_map(struct bpf_object *obj,
 	var_extra = btf_var(var);
 	map_name = btf__name_by_offset(obj->btf, var->name_off);
 
-	if (map_name == NULL || map_name[0] == '\0') {
+	if (str_is_empty(map_name)) {
 		pr_warn("map #%d: empty name.\n", var_idx);
 		return -EINVAL;
 	}
@@ -4281,7 +4281,7 @@ static int bpf_object__collect_externs(struct bpf_object *obj)
 		if (!sym_is_extern(sym))
 			continue;
 		ext_name = elf_sym_str(obj, sym->st_name);
-		if (!ext_name || !ext_name[0])
+		if (str_is_empty(ext_name))
 			continue;
 
 		ext = obj->externs;
-- 
2.34.1