[PATCH] libtracefs: Prefer using const pointer arguments

["Yordan Karadzhov (VMware)" <y.karadz@xxxxxxxxx>]

All functions should receive const pointer arguments, except in the
cases when the argument object itself needs to be modified.

Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@xxxxxxxxx>
---
 include/tracefs.h      | 15 ++++++++-------
 src/tracefs-instance.c | 17 +++++++++--------
 2 files changed, 17 insertions(+), 15 deletions(-)

diff --git a/include/tracefs.h b/include/tracefs.h
index f3eec62..e54f791 100644
--- a/include/tracefs.h
+++ b/include/tracefs.h
@@ -25,12 +25,13 @@ struct tracefs_instance *tracefs_instance_create(const char *name);
 struct tracefs_instance *tracefs_instance_alloc(const char *tracing_dir,
 						const char *name);
 int tracefs_instance_destroy(struct tracefs_instance *instance);
-bool tracefs_instance_is_new(struct tracefs_instance *instance);
-const char *tracefs_instance_get_name(struct tracefs_instance *instance);
-const char *tracefs_instance_get_trace_dir(struct tracefs_instance *instance);
+bool tracefs_instance_is_new(const struct tracefs_instance *instance);
+const char *tracefs_instance_get_name(const struct tracefs_instance *instance);
+const char *tracefs_instance_get_trace_dir(const struct tracefs_instance *instance);
 char *
-tracefs_instance_get_file(struct tracefs_instance *instance, const char *file);
-char *tracefs_instance_get_dir(struct tracefs_instance *instance);
+tracefs_instance_get_file(const struct tracefs_instance *instance,
+			  const char *file);
+char *tracefs_instance_get_dir(const struct tracefs_instance *instance);
 int tracefs_instance_file_write(struct tracefs_instance *instance,
 				const char *file, const char *str);
 char *tracefs_instance_file_read(struct tracefs_instance *instance,
@@ -42,8 +43,8 @@ int tracefs_instance_file_open(struct tracefs_instance *instance,
 int tracefs_instances_walk(int (*callback)(const char *, void *), void *context);
 
 bool tracefs_instance_exists(const char *name);
-bool tracefs_file_exists(struct tracefs_instance *instance, char *name);
-bool tracefs_dir_exists(struct tracefs_instance *instance, char *name);
+bool tracefs_file_exists(struct tracefs_instance *instance, const char *name);
+bool tracefs_dir_exists(struct tracefs_instance *instance, const char *name);
 
 int tracefs_trace_is_on(struct tracefs_instance *instance);
 int tracefs_trace_on(struct tracefs_instance *instance);
diff --git a/src/tracefs-instance.c b/src/tracefs-instance.c
index 0df4e13..ba467a8 100644
--- a/src/tracefs-instance.c
+++ b/src/tracefs-instance.c
@@ -100,7 +100,7 @@ out:
  * Returns true, if the ftrace instance is newly created by the library or
  * false otherwise.
  */
-bool tracefs_instance_is_new(struct tracefs_instance *instance)
+bool tracefs_instance_is_new(const struct tracefs_instance *instance)
 {
 	if (instance && (instance->flags & FLAG_INSTANCE_NEWLY_CREATED))
 		return true;
@@ -229,7 +229,8 @@ int tracefs_instance_destroy(struct tracefs_instance *instance)
  * Must use tracefs_put_tracing_file() to free the returned string.
  */
 char *
-tracefs_instance_get_file(struct tracefs_instance *instance, const char *file)
+tracefs_instance_get_file(const struct tracefs_instance *instance,
+			  const char *file)
 {
 	char *path = NULL;
 	int ret;
@@ -255,7 +256,7 @@ tracefs_instance_get_file(struct tracefs_instance *instance, const char *file)
  *
  * Must use tracefs_put_tracing_file() to free the returned string.
  */
-char *tracefs_instance_get_dir(struct tracefs_instance *instance)
+char *tracefs_instance_get_dir(const struct tracefs_instance *instance)
 {
 	char *path = NULL;
 	int ret;
@@ -283,7 +284,7 @@ char *tracefs_instance_get_dir(struct tracefs_instance *instance)
  * Returns the name of the given @instance.
  * The returned string must *not* be freed.
  */
-const char *tracefs_instance_get_name(struct tracefs_instance *instance)
+const char *tracefs_instance_get_name(const struct tracefs_instance *instance)
 {
 	if (instance)
 		return instance->name;
@@ -297,7 +298,7 @@ const char *tracefs_instance_get_name(struct tracefs_instance *instance)
  * Returns the top trace directory where the given @instance is configured.
  * The returned string must *not* be freed.
  */
-const char *tracefs_instance_get_trace_dir(struct tracefs_instance *instance)
+const char *tracefs_instance_get_trace_dir(const struct tracefs_instance *instance)
 {
 	if (instance)
 		return instance->trace_dir;
@@ -436,7 +437,7 @@ int tracefs_instance_file_open(struct tracefs_instance *instance,
 }
 
 static bool check_file_exists(struct tracefs_instance *instance,
-			     char *name, bool dir)
+			     const char *name, bool dir)
 {
 	char file[PATH_MAX];
 	struct stat st;
@@ -482,7 +483,7 @@ bool tracefs_instance_exists(const char *name)
  *
  * If a directory with the given name exists, false is returned.
  */
-bool tracefs_file_exists(struct tracefs_instance *instance, char *name)
+bool tracefs_file_exists(struct tracefs_instance *instance, const char *name)
 {
 	return check_file_exists(instance, name, false);
 }
@@ -494,7 +495,7 @@ bool tracefs_file_exists(struct tracefs_instance *instance, char *name)
  *
  * Returns true if the directory exists, false otherwise
  */
-bool tracefs_dir_exists(struct tracefs_instance *instance, char *name)
+bool tracefs_dir_exists(struct tracefs_instance *instance, const char *name)
 {
 	return check_file_exists(instance, name, true);
 }
-- 
2.25.1