diff --git a/core_backup.c b/core_backup.c
index 7f083fdc69..e660292414 100644
--- a/core_backup.c
+++ b/core_backup.c
@@ -279,9 +279,7 @@ bool core_backup_get_backup_crc(char *backup_path, uint32_t *crc)
                goto error;
 
             /* Convert to an integer */
-            *crc = (uint32_t)string_hex_to_unsigned(crc_str);
-
-            if (*crc == 0)
+            if ((*crc = (uint32_t)string_hex_to_unsigned(crc_str)) == 0)
                goto error;
 
             string_list_free(metadata_list);
diff --git a/core_updater_list.c b/core_updater_list.c
index 841abdd11d..54438aea78 100644
--- a/core_updater_list.c
+++ b/core_updater_list.c
@@ -371,9 +371,7 @@ static bool core_updater_list_set_crc(
    if (!entry || string_is_empty(crc_str))
       return false;
 
-   crc = (uint32_t)string_hex_to_unsigned(crc_str);
-
-   if (crc == 0)
+   if ((crc = (uint32_t)string_hex_to_unsigned(crc_str)) == 0)
       return false;
 
    entry->crc = crc;
diff --git a/libretro-common/file/file_path.c b/libretro-common/file/file_path.c
index 86295751ea..0b2f953788 100644
--- a/libretro-common/file/file_path.c
+++ b/libretro-common/file/file_path.c
@@ -82,7 +82,11 @@ struct path_linked_list* path_linked_list_new(void)
    return paths_list;
 }
 
-/* Free the entire linked list */
+/**
+ * path_linked_list_free:
+ *
+ * Free the entire linked list
+ **/
 void path_linked_list_free(struct path_linked_list *in_path_linked_list)
 {
    struct path_linked_list *node_tmp = (struct path_linked_list*)in_path_linked_list;
@@ -99,11 +103,14 @@ void path_linked_list_free(struct path_linked_list *in_path_linked_list)
 }
 
 /**
+ * path_linked_list_add_path:
+ *
  * Add a node to the linked list with this path
  * If the first node's path if it's not yet set the path
  * on this node instead
 **/
-void path_linked_list_add_path(struct path_linked_list *in_path_linked_list, char *path)
+void path_linked_list_add_path(struct path_linked_list *in_path_linked_list,
+      char *path)
 {
     /* If the first item does not have a path this is
       a list which has just been created, so we just fill 
@@ -142,9 +149,9 @@ void path_linked_list_add_path(struct path_linked_list *in_path_linked_list, cha
  * Find delimiter of an archive file. Only the first '#'
  * after a compression extension is considered.
  *
- * Returns: pointer to the delimiter in the path if it contains
+ * @return pointer to the delimiter in the path if it contains
  * a path inside a compressed file, otherwise NULL.
- */
+ **/
 const char *path_get_archive_delim(const char *path)
 {
    char buf[5];
@@ -198,8 +205,8 @@ const char *path_get_archive_delim(const char *path)
  * Gets extension of file. Only '.'s
  * after the last slash are considered.
  *
- * Returns: extension part from the path.
- */
+ * @return extension part from the path.
+ **/
 const char *path_get_extension(const char *path)
 {
    const char *ext;
@@ -216,12 +223,12 @@ const char *path_get_extension(const char *path)
  * text after and including the last '.'.
  * Only '.'s after the last slash are considered.
  *
- * Returns:
+ * @return
  * 1) If path has an extension, returns path with the
  *    extension removed.
  * 2) If there is no extension, returns NULL.
  * 3) If path is empty or NULL, returns NULL
- */
+ **/
 char *path_remove_extension(char *path)
 {
    char *last = !string_is_empty(path)
@@ -239,7 +246,7 @@ char *path_remove_extension(char *path)
  *
  * Checks if path is a compressed file.
  *
- * Returns: true (1) if path is a compressed file, otherwise false (0).
+ * @return true if path is a compressed file, otherwise false.
  **/
 bool path_is_compressed_file(const char* path)
 {
@@ -286,6 +293,17 @@ void fill_pathname(char *out_path, const char *in_path,
 }
 
 
+/**
+ * find_last_slash:
+ * @str                : path
+ * @size               : size of path
+ *
+ * Find last slash in path. Tries to find
+ * a backslash on Windows too which takes precedence
+ * over regular slash.
+
+ * @return pointer to last slash/backslash found in @str.
+ **/
 char *find_last_slash(const char *str)
 {
    const char *slash     = strrchr(str, '/');
@@ -362,7 +380,7 @@ size_t fill_pathname_dir(char *in_dir, const char *in_basename,
  *
  * Copies basename of @in_path into @out_path.
  *
- * @return length of the string copied into @out
+ * @return Length of the string copied into @out
  **/
 size_t fill_pathname_base(char *out, const char *in_path, size_t size)
 {
@@ -398,7 +416,8 @@ void fill_pathname_basedir(char *out_dir,
  *
  * Copies only the parent directory name of @in_dir into @out_dir.
  * The two buffers must not overlap. Removes trailing '/'.
- * Returns true on success, false if a slash was not found in the path.
+ *
+ * @return true on success, false if a slash was not found in the path.
  **/
 bool fill_pathname_parent_dir_name(char *out_dir,
       const char *in_dir, size_t size)
@@ -446,7 +465,8 @@ bool fill_pathname_parent_dir_name(char *out_dir,
  *
  * Copies parent directory of @in_dir into @out_dir.
  * Assumes @in_dir is a directory. Keeps trailing '/'.
- * If the path was already at the root directory, @out_dir will be an empty string.
+ * If the path was already at the root directory,
+ * @out_dir will be an empty string.
  **/
 void fill_pathname_parent_dir(char *out_dir,
       const char *in_dir, size_t size)
@@ -506,16 +526,15 @@ void fill_str_dated_filename(char *out_filename,
 
    rtime_localtime(&cur_time, &tm_);
 
+   strlcpy(out_filename, in_str, size);
    if (string_is_empty(ext))
    {
       strftime(format, sizeof(format), "-%y%m%d-%H%M%S", &tm_);
-      strlcpy(out_filename, in_str, size);
       strlcat(out_filename, format, size);
    }
    else
    {
       strftime(format, sizeof(format), "-%y%m%d-%H%M%S.", &tm_);
-      strlcpy(out_filename, in_str, size);
       strlcat(out_filename, format, size);
       strlcat(out_filename, ext,    size);
    }
@@ -584,7 +603,7 @@ void path_parent_dir(char *path, size_t len)
  *
  * Get basename from @path.
  *
- * Returns: basename from path.
+ * @return basename from path.
  **/
 const char *path_basename(const char *path)
 {
@@ -604,6 +623,15 @@ const char *path_basename(const char *path)
 }
 
 /* Specialized version */
+/**
+ * path_basename_nocompression:
+ * @path               : path
+ *
+ * Specialized version of path_basename().
+ * Get basename from @path.
+ *
+ * @return basename from path.
+ **/
 const char *path_basename_nocompression(const char *path)
 {
    /* We cut at the last slash */
@@ -619,7 +647,7 @@ const char *path_basename_nocompression(const char *path)
  *
  * Checks if @path is an absolute path or a relative path.
  *
- * Returns: true if path is absolute, false if path is relative.
+ * @return true if path is absolute, false if path is relative.
  **/
 bool path_is_absolute(const char *path)
 {
@@ -655,7 +683,7 @@ bool path_is_absolute(const char *path)
  *
  * Relative paths are rebased on the current working dir.
  *
- * Returns: @buf if successful, NULL otherwise.
+ * @return @buf if successful, NULL otherwise.
  * Note: Not implemented on consoles
  * Note: Symlinks are only resolved on Unix-likes
  * Note: The current working dir might not be what you expect,
@@ -921,9 +949,9 @@ size_t fill_pathname_join_delim(char *out_path, const char *dir,
    size_t copied;
    /* behavior of strlcpy is undefined if dst and src overlap */
    if (out_path == dir)
-      copied = strlen(dir);
+      copied          = strlen(dir);
    else
-      copied = strlcpy(out_path, dir, size);
+      copied          = strlcpy(out_path, dir, size);
 
    out_path[copied]   = delim;
    out_path[copied+1] = '\0';
@@ -1060,28 +1088,53 @@ void fill_pathname_abbreviate_special(char *out_path,
    retro_assert(strlcpy(out_path, in_path, size) < size);
 }
 
-/* Changes the slashes to the correct kind for the os 
- * So forward slash on linux and backslash on Windows */
+/**
+ * pathname_conform_slashes_to_os:
+ *
+ * @path               : path
+ *
+ * Leaf function.
+ *
+ * Changes the slashes to the correct kind for the os 
+ * So forward slash on linux and backslash on Windows
+ **/
 void pathname_conform_slashes_to_os(char *path)
 {
    /* Conform slashes to os standard so we get proper matching */
-   char* p;
+   char *p;
    for (p = path; *p; p++)
       if (*p == '/' || *p == '\\')
          *p = PATH_DEFAULT_SLASH_C();
 }
 
-/* Change all shashes to forward so they are more portable between Windows and Linux */
+/**
+ * pathname_make_slashes_portable:
+ * @path               : path
+ *
+ * Leaf function.
+ *
+ * Change all slashes to forward so they are more 
+ * portable between Windows and Linux
+ **/
 void pathname_make_slashes_portable(char *path)
 {
    /* Conform slashes to os standard so we get proper matching */
-   char* p;
+   char *p;
    for (p = path; *p; p++)
       if (*p == '/' || *p == '\\')
          *p = '/';
 }
 
-/* Get the number of slashes in a path, returns an integer */
+/**
+ * get_pathname_num_slashes:
+ * @in_path            : input path
+ *
+ * Leaf function.
+ *
+ * Get the number of slashes in a path.
+ *
+ * @return number of slashes found in @in_path.
+ **/
 static int get_pathname_num_slashes(const char *in_path)
 {
    int num_slashes = 0;
@@ -1098,11 +1151,18 @@ static int get_pathname_num_slashes(const char *in_path)
    return num_slashes;
 }
 
-/* Fills the supplied path with either the abbreviated path or the relative path, which ever
- * one is has less depth / number of slashes
- * If lengths of abbreviated and relative paths are the same the relative path will be used
- * in_path can be an absolute, relative or abbreviated path */
-void fill_pathname_abbreviated_or_relative(char *out_path, const char *in_refpath, const char *in_path, size_t size)
+/**
+ * fill_pathname_abbreviated_or_relative:
+ *
+ * Fills the supplied path with either the abbreviated path or 
+ * the relative path, which ever one has less depth / number of slashes
+ * 
+ * If lengths of abbreviated and relative paths are the same,
+ * the relative path will be used
+ * @in_path can be an absolute, relative or abbreviated path
+ **/
+void fill_pathname_abbreviated_or_relative(char *out_path,
+      const char *in_refpath, const char *in_path, size_t size)
 {
    char in_path_conformed[PATH_MAX_LENGTH];
    char in_refpath_conformed[PATH_MAX_LENGTH];
@@ -1111,15 +1171,13 @@ void fill_pathname_abbreviated_or_relative(char *out_path, const char *in_refpat
    char relative_path[PATH_MAX_LENGTH];
    char abbreviated_path[PATH_MAX_LENGTH];
    
-   in_path_conformed[0]    = '\0';
-   in_refpath_conformed[0] = '\0';
    expanded_path[0]        = '\0';
    absolute_path[0]        = '\0';
    relative_path[0]        = '\0';
    abbreviated_path[0]     = '\0';
 
-   strcpy_literal(in_path_conformed, in_path);
-   strcpy_literal(in_refpath_conformed, in_refpath);
+   strlcpy(in_path_conformed, in_path, sizeof(in_path_conformed));
+   strlcpy(in_refpath_conformed, in_refpath, sizeof(in_refpath_conformed));
 
    pathname_conform_slashes_to_os(in_path_conformed);
    pathname_conform_slashes_to_os(in_refpath_conformed);
diff --git a/libretro-common/include/file/file_path.h b/libretro-common/include/file/file_path.h
index f77cfb2b60..8687f716c0 100644
--- a/libretro-common/include/file/file_path.h
+++ b/libretro-common/include/file/file_path.h
@@ -103,12 +103,12 @@ bool path_is_compressed_file(const char *path);
  * path_get_archive_delim:
  * @path               : path
  *
- * Gets delimiter of an archive file. Only the first '#'
+ * Find delimiter of an archive file. Only the first '#'
  * after a compression extension is considered.
  *
- * Returns: pointer to the delimiter in the path if it contains
- * a compressed file, otherwise NULL.
- */
+ * @return pointer to the delimiter in the path if it contains
+ * a path inside a compressed file, otherwise NULL.
+ **/
 const char *path_get_archive_delim(const char *path);
 
 /**
@@ -118,8 +118,12 @@ const char *path_get_archive_delim(const char *path);
  * Gets extension of file. Only '.'s
  * after the last slash are considered.
  *
- * Returns: extension part from the path.
- */
+ * Hidden non-leaf function cost:
+ * - calls string_is_empty
+ * - calls strrchr
+ *
+ * @return extension part from the path.
+ **/
 const char *path_get_extension(const char *path);
 
 /**
@@ -130,7 +134,10 @@ const char *path_get_extension(const char *path);
  * text after and including the last '.'.
  * Only '.'s after the last slash are considered.
  *
- * Returns:
+ * Hidden non-leaf function cost:
+ * - calls strrchr
+ *
+ * @return
  * 1) If path has an extension, returns path with the
  *    extension removed.
  * 2) If there is no extension, returns NULL.
@@ -144,9 +151,26 @@ char *path_remove_extension(char *path);
  *
  * Get basename from @path.
  *
- * Returns: basename from path.
+ * Hidden non-leaf function cost:
+ * - Calls path_get_archive_delim()
+ *   - can call find_last_slash once if it returns NULL
+ *
+ * @return basename from path.
  **/
 const char *path_basename(const char *path);
+
+/**
+ * path_basename_nocompression:
+ * @path               : path
+ *
+ * Specialized version of path_basename().
+ * Get basename from @path.
+ *
+ * Hidden non-leaf function cost:
+ * - Calls find_last_slash
+ *
+ * @return basename from path.
+ **/
 const char *path_basename_nocompression(const char *path);
 
 /**
@@ -179,7 +203,7 @@ void path_parent_dir(char *path, size_t len);
  *
  * Relative paths are rebased on the current working dir.
  *
- * Returns: @buf if successful, NULL otherwise.
+ * @return @buf if successful, NULL otherwise.
  * Note: Not implemented on consoles
  * Note: Symlinks are only resolved on Unix-likes
  * Note: The current working dir might not be what you expect,
@@ -202,7 +226,8 @@ char *path_resolve_realpath(char *buf, size_t size, bool resolve_symlinks);
  *
  * E.g. path /a/b/e/f.cgp with base /a/b/c/d/ turns into ../../e/f.cgp
  **/
-size_t path_relative_to(char *out, const char *path, const char *base, size_t size);
+size_t path_relative_to(char *out, const char *path, const char *base,
+      size_t size);
 
 /**
  * path_is_absolute:
@@ -210,7 +235,7 @@ size_t path_relative_to(char *out, const char *path, const char *base, size_t si
  *
  * Checks if @path is an absolute path or a relative path.
  *
- * Returns: true if path is absolute, false if path is relative.
+ * @return true if path is absolute, false if path is relative.
  **/
 bool path_is_absolute(const char *path);
 
@@ -234,6 +259,11 @@ bool path_is_absolute(const char *path);
  * out_path = "/foo/bar/baz/boo.asm"
  * E.g.: in_path = "/foo/bar/baz/boo.c", replace = ""     =>
  * out_path = "/foo/bar/baz/boo"
+ *
+ * Hidden non-leaf function cost:
+ * - calls strlcpy 2x
+ * - calls strrchr
+ * - calls strlcat
  */
 void fill_pathname(char *out_path, const char *in_path,
       const char *replace, size_t size);
@@ -249,6 +279,12 @@ void fill_pathname(char *out_path, const char *in_path,
  *
  * E.g.:
  * out_filename = "RetroArch-{month}{day}-{Hours}{Minutes}.{@ext}"
+ *
+ * Hidden non-leaf function cost:
+ * - Calls rtime_localtime()
+ * - Calls strftime
+ * - Calls strlcat
+ *
  **/
 size_t fill_dated_filename(char *out_filename,
       const char *ext, size_t size);
@@ -265,17 +301,31 @@ size_t fill_dated_filename(char *out_filename,
  *
  * E.g.:
  * out_filename = "RetroArch-{year}{month}{day}-{Hour}{Minute}{Second}.{@ext}"
+ *
+ * Hidden non-leaf function cost:
+ * - Calls time
+ * - Calls rtime_localtime
+ * - Calls strlcpy
+ * - Calls string_is_empty
+ * - Calls strftime
+ * - Calls strlcat at least 2x
  **/
 void fill_str_dated_filename(char *out_filename,
       const char *in_str, const char *ext, size_t size);
 
 /**
  * find_last_slash:
- * @str : input path
+ * @str                : path
+ * @size               : size of path
  *
- * Gets a pointer to the last slash in the input path.
+ * Find last slash in path. Tries to find
+ * a backslash on Windows too which takes precedence
+ * over regular slash.
+
+ * Hidden non-leaf function cost: 
+ * - calls strrchr
  *
- * Returns: a pointer to the last slash in the input path.
+ * @return pointer to last slash/backslash found in @str.
  **/
 char *find_last_slash(const char *str);
 
@@ -295,6 +345,11 @@ char *find_last_slash(const char *str);
  *
  * E.g..: in_dir = "/tmp/some_dir", in_basename = "/some_content/foo.c",
  * replace = ".asm" => in_dir = "/tmp/some_dir/foo.c.asm"
+ *
+ * Hidden non-leaf function cost:
+ * - Calls fill_pathname_slash()
+ * - Calls path_basename()
+ * - Calls strlcat 2x
  **/
 size_t fill_pathname_dir(char *in_dir, const char *in_basename,
       const char *replace, size_t size);
@@ -306,6 +361,12 @@ size_t fill_pathname_dir(char *in_dir, const char *in_basename,
  * @size               : size of output path
  *
  * Copies basename of @in_path into @out_path.
+ *
+ * Hidden non-leaf function cost:
+ * - Calls path_basename()
+ * - Calls strlcpy
+ *
+ * @return length of the string copied into @out
  **/
 size_t fill_pathname_base(char *out_path, const char *in_path, size_t size);
 
@@ -318,6 +379,10 @@ size_t fill_pathname_base(char *out_path, const char *in_path, size_t size);
  * Copies base directory of @in_path into @out_path.
  * If in_path is a path without any slashes (relative current directory),
  * @out_path will get path "./".
+ *
+ * Hidden non-leaf function cost:
+ * - Calls strlcpy
+ * - Calls path_basedir()
  **/
 void fill_pathname_basedir(char *out_path, const char *in_path, size_t size);
 
@@ -329,7 +394,13 @@ void fill_pathname_basedir(char *out_path, const char *in_path, size_t size);
  *
  * Copies only the parent directory name of @in_dir into @out_dir.
  * The two buffers must not overlap. Removes trailing '/'.
- * Returns true on success, false if a slash was not found in the path.
+ *
+ * Hidden non-leaf function cost:
+ * - Calls strdup
+ * - Calls find_last_slash x times
+ * - Can call strlcpy
+ *
+ * @return true on success, false if a slash was not found in the path.
  **/
 bool fill_pathname_parent_dir_name(char *out_dir,
       const char *in_dir, size_t size);
@@ -343,6 +414,11 @@ bool fill_pathname_parent_dir_name(char *out_dir,
  * Copies parent directory of @in_dir into @out_dir.
  * Assumes @in_dir is a directory. Keeps trailing '/'.
  * If the path was already at the root directory, @out_dir will be an empty string.
+ *
+ * Hidden non-leaf function cost:
+ * - Can call strlcpy if (@out_dir != @in_dir)
+ * - Calls strlen if (@out_dir == @in_dir)
+ * - Calls path_parent_dir()
  **/
 void fill_pathname_parent_dir(char *out_dir,
       const char *in_dir, size_t size);
@@ -372,6 +448,11 @@ void fill_pathname_resolve_relative(char *out_path, const char *in_refpath,
  * Joins a directory (@dir) and path (@path) together.
  * Makes sure not to get  two consecutive slashes
  * between directory and path.
+ * 
+ * Hidden non-leaf function cost: 
+ * - calls strlcpy
+ * - calls fill_pathname_slash()
+ * - calls strlcat
  **/
 size_t fill_pathname_join(char *out_path, const char *dir,
       const char *path, size_t size);
@@ -391,6 +472,11 @@ size_t fill_pathname_join_special_ext(char *out_path,
  *
  * Joins a directory (@dir) and path (@path) together
  * using the given delimiter (@delim).
+ *
+ * Hidden non-leaf function cost: 
+ * - can call strlen
+ * - can call strlcpy
+ * - can call strlcat
  **/
 size_t fill_pathname_join_delim(char *out_path, const char *dir,
       const char *path, const char delim, size_t size);
@@ -401,10 +487,40 @@ void fill_pathname_expand_special(char *out_path,
 void fill_pathname_abbreviate_special(char *out_path,
       const char *in_path, size_t size);
 
-void fill_pathname_abbreviated_or_relative(char *out_path, const char *in_refpath, const char *in_path, size_t size);
+/**
+ * fill_pathname_abbreviated_or_relative:
+ *
+ * Fills the supplied path with either the abbreviated path or 
+ * the relative path, which ever one has less depth / number of slashes
+ * 
+ * If lengths of abbreviated and relative paths are the same,
+ * the relative path will be used
+ * @in_path can be an absolute, relative or abbreviated path
+ **/
+void fill_pathname_abbreviated_or_relative(char *out_path,
+		const char *in_refpath, const char *in_path, size_t size);
 
+/**
+ * pathname_conform_slashes_to_os:
+ *
+ * @path               : path
+ * 
+ * Leaf function.
+ *
+ * Changes the slashes to the correct kind for the os 
+ * So forward slash on linux and backslash on Windows
+ **/
 void pathname_conform_slashes_to_os(char *path);
 
+/**
+ * pathname_make_slashes_portable:
+ * @path               : path
+ *
+ * Leaf function.
+ *
+ * Change all slashes to forward so they are more 
+ * portable between Windows and Linux
+ **/
 void pathname_make_slashes_portable(char *path);
 
 /**
@@ -422,8 +538,8 @@ void path_basedir_wrapper(char *path);
  *
  * Checks if character (@c) is a slash.
  *
- * Returns: true (1) if character is a slash, otherwise false (0).
- */
+ * @return true if character is a slash, otherwise false.
+ **/
 #ifdef _WIN32
 #define PATH_CHAR_IS_SLASH(c) (((c) == '/') || ((c) == '\\'))
 #else
@@ -435,8 +551,8 @@ void path_basedir_wrapper(char *path);
  *
  * Gets the default slash separator.
  *
- * Returns: default slash separator.
- */
+ * @return default slash separator.
+ **/
 #ifdef _WIN32
 #define PATH_DEFAULT_SLASH() "\\"
 #define PATH_DEFAULT_SLASH_C() '\\'
@@ -452,6 +568,11 @@ void path_basedir_wrapper(char *path);
  *
  * Assumes path is a directory. Appends a slash
  * if not already there.
+
+ * Hidden non-leaf function cost: 
+ * - calls find_last_slash()
+ *   - can call strlcat once if it returns false
+ * - calls strlen
  **/
 void fill_pathname_slash(char *path, size_t size);
 
@@ -467,7 +588,7 @@ void fill_pathname_home_dir(char *buf, size_t size);
  *
  * Create directory on filesystem.
  *
- * Returns: true (1) if directory could be created, otherwise false (0).
+ * @return true if directory could be created, otherwise false.
  **/
 bool path_mkdir(const char *dir);
 
@@ -477,7 +598,7 @@ bool path_mkdir(const char *dir);
  *
  * Checks if path is a directory.
  *
- * Returns: true (1) if path is a directory, otherwise false (0).
+ * @return true if path is a directory, otherwise false.
  */
 bool path_is_directory(const char *path);
 
diff --git a/libretro-common/include/string/stdstring.h b/libretro-common/include/string/stdstring.h
index 6431f4aa72..7b5873ce16 100644
--- a/libretro-common/include/string/stdstring.h
+++ b/libretro-common/include/string/stdstring.h
@@ -92,16 +92,20 @@ static INLINE bool string_ends_with_size(const char *str, const char *suffix,
 
 static INLINE bool string_ends_with(const char *str, const char *suffix)
 {
-   if (!str || !suffix)
-      return false;
-   return string_ends_with_size(str, suffix, strlen(str), strlen(suffix));
+   return str && suffix && string_ends_with_size(str, suffix, strlen(str), strlen(suffix));
 }
 
-/* Returns the length of 'str' (c.f. strlen()), but only
+/**
+ * strlen_size:
+ *
+ * Leaf function.
+ *
+ * @return the length of 'str' (c.f. strlen()), but only
  * checks the first 'size' characters
  * - If 'str' is NULL, returns 0
  * - If 'str' is not NULL and no '\0' character is found
- *   in the first 'size' characters, returns 'size' */
+ *   in the first 'size' characters, returns 'size'
+ **/
 static INLINE size_t strlen_size(const char *str, size_t size)
 {
    size_t i = 0;
@@ -158,16 +162,30 @@ char *string_ucwords(char *s);
 char *string_replace_substring(const char *in, const char *pattern,
       const char *by);
 
-/* Remove leading whitespaces */
+/**
+ * string_trim_whitespace_left:
+ *
+ * Remove leading whitespaces
+ **/
 char *string_trim_whitespace_left(char *const s);
 
-/* Remove trailing whitespaces */
+/**
+ * string_trim_whitespace_right:
+ *
+ * Remove trailing whitespaces
+ **/
 char *string_trim_whitespace_right(char *const s);
 
-/* Remove leading and trailing whitespaces */
+/**
+ * string_trim_whitespace:
+ *
+ * Remove leading and trailing whitespaces
+ **/
 char *string_trim_whitespace(char *const s);
 
-/*
+/**
+ * word_wrap:
+ *
  * Wraps string specified by 'src' to destination buffer
  * specified by 'dst' and 'dst_size'.
  * This function assumes that all glyphs in the string
@@ -184,11 +202,13 @@ char *string_trim_whitespace(char *const s);
  *                        compatibility with word_wrap_wideglyph().
  * @param max_lines       max lines of destination string.
  *                        0 means no limit.
- */
+ **/
 void word_wrap(char *dst, size_t dst_size, const char *src,
       int line_width, int wideglyph_width, unsigned max_lines);
 
-/*
+/**
+ * word_wrap_wideglyph:
+ *
  * Wraps string specified by 'src' to destination buffer
  * specified by 'dst' and 'dst_size'.
  * This function assumes that all glyphs in the string
@@ -219,14 +239,17 @@ void word_wrap(char *dst, size_t dst_size, const char *src,
  *                          would be 200
  * @param max_lines       max lines of destination string.
  *                        0 means no limit.
- */
+ **/
 void word_wrap_wideglyph(char *dst, size_t dst_size, const char *src,
       int line_width, int wideglyph_width, unsigned max_lines);
 
-/* Splits string into tokens seperated by 'delim'
+/**
+ * string_tokenize:
+ *
+ * Splits string into tokens seperated by @delim
  * > Returned token string must be free()'d
  * > Returns NULL if token is not found
- * > After each call, 'str' is set to the position after the
+ * > After each call, @str is set to the position after the
  *   last found token
  * > Tokens *include* empty strings
  * Usage example:
@@ -239,48 +262,118 @@ void word_wrap_wideglyph(char *dst, size_t dst_size, const char *src,
  *        free(token);
  *        token = NULL;
  *    }
- */
+ **/
 char* string_tokenize(char **str, const char *delim);
 
-/* Removes every instance of character 'c' from 'str' */
+/**
+ * string_remove_all_chars:
+ * @str                : input string (must be non-NULL, otherwise UB)
+ *
+ * Leaf function.
+ *
+ * Removes every instance of character @c from @str
+ **/
 void string_remove_all_chars(char *str, char c);
 
-/* Replaces every instance of character 'find' in 'str'
- * with character 'replace' */
+/**
+ * string_replace_all_chars:
+ * @str                : input string (must be non-NULL, otherwise UB)
+ * @find               : character to find
+ * @replace            : character to replace @find with
+ *
+ * Hidden non-leaf function cost:
+ * - Calls strchr (in a loop)
+ *
+ * Replaces every instance of character @find in @str
+ * with character @replace
+ **/
 void string_replace_all_chars(char *str, char find, char replace);
 
-/* Converts string to unsigned integer.
- * Returns 0 if string is invalid  */
+/**
+ * string_to_unsigned:
+ * @str                : input string
+ *
+ * Converts string to unsigned integer.
+ *
+ * @return 0 if string is invalid, otherwise > 0
+ **/
 unsigned string_to_unsigned(const char *str);
 
-/* Converts hexadecimal string to unsigned integer.
+/**
+ * string_hex_to_unsigned:
+ * @str                : input string (must be non-NULL, otherwise UB)
+ *
+ * Converts hexadecimal string to unsigned integer.
  * Handles optional leading '0x'.
- * Returns 0 if string is invalid  */
+ *
+ * @return 0 if string is invalid, otherwise > 0
+ **/
 unsigned string_hex_to_unsigned(const char *str);
 
 char *string_init(const char *src);
 
 void string_set(char **string, const char *src);
 
-/* Get the total number of occurrences of a character in the given string. */
+/**
+ * string_count_occurrences_single_character:
+ *
+ * Leaf function.
+ *
+ * Get the total number of occurrences of character @c in @str.
+ *
+ * @return Total number of occurrences of character @c
+ */
 int string_count_occurrences_single_character(const char *str, char c);
 
-/* Replaces all spaces with the given character. */
+/**
+ * string_replace_whitespace_with_single_character:
+ * 
+ * Leaf function.
+ *
+ * Replaces all spaces with given character @c.
+ **/
 void string_replace_whitespace_with_single_character(char *str, char c);
 
-/* Replaces multiple spaces with a single space in a string. */
+/**
+ * string_replace_multi_space_with_single_space:
+ *
+ * Leaf function.
+ *
+ * Replaces multiple spaces with a single space in a string.
+ **/
 void string_replace_multi_space_with_single_space(char *str);
 
-/* Remove all spaces from the given string. */
+/**
+ * string_remove_all_whitespace:
+ *
+ * Leaf function.
+ *
+ * Remove all spaces from the given string.
+ **/
 void string_remove_all_whitespace(char *str_trimmed, const char *str);
 
 /* Retrieve the last occurance of the given character in a string. */
 int string_index_last_occurance(const char *str, char c);
 
-/* Find the position of a substring in a string. */
+/**
+ * string_find_index_substring_string:
+ * @str                : input string (must be non-NULL, otherwise UB)
+ * @substr             : substring to find in @str
+ *
+ * Hidden non-leaf function cost:
+ * - Calls strstr
+ *
+ * Find the position of substring @substr in string @str.
+ **/
 int string_find_index_substring_string(const char *str, const char *substr);
 
-/* Strips non-ASCII characters from a string. */
+/**
+ * string_copy_only_ascii:
+ *
+ * Leaf function.
+ *
+ * Strips non-ASCII characters from a string.
+ **/
 void string_copy_only_ascii(char *str_stripped, const char *str);
 
 extern const unsigned char lr_char_props[256];
diff --git a/libretro-common/string/stdstring.c b/libretro-common/string/stdstring.c
index c8806e08bb..d800042b64 100644
--- a/libretro-common/string/stdstring.c
+++ b/libretro-common/string/stdstring.c
@@ -136,7 +136,11 @@ char *string_replace_substring(const char *in,
    return out;
 }
 
-/* Remove leading whitespaces */
+/**
+ * string_trim_whitespace_left:
+ *
+ * Remove leading whitespaces
+ **/
 char *string_trim_whitespace_left(char *const s)
 {
    if (s && *s)
@@ -157,7 +161,11 @@ char *string_trim_whitespace_left(char *const s)
    return s;
 }
 
-/* Remove trailing whitespaces */
+/**
+ * string_trim_whitespace_right:
+ *
+ * Remove trailing whitespaces
+ **/
 char *string_trim_whitespace_right(char *const s)
 {
    if (s && *s)
@@ -177,7 +185,11 @@ char *string_trim_whitespace_right(char *const s)
    return s;
 }
 
-/* Remove leading and trailing whitespaces */
+/**
+ * string_trim_whitespace:
+ *
+ * Remove leading and trailing whitespaces
+ **/
 char *string_trim_whitespace(char *const s)
 {
    string_trim_whitespace_right(s);  /* order matters */
@@ -186,7 +198,28 @@ char *string_trim_whitespace(char *const s)
    return s;
 }
 
-void word_wrap(char *dst, size_t dst_size, const char *src, int line_width, int wideglyph_width, unsigned max_lines)
+/**
+ * word_wrap:
+ *
+ * Wraps string specified by 'src' to destination buffer
+ * specified by 'dst' and 'dst_size'.
+ * This function assumes that all glyphs in the string
+ * have an on-screen pixel width similar to that of
+ * regular Latin characters - i.e. it will not wrap
+ * correctly any text containing so-called 'wide' Unicode
+ * characters (e.g. CJK languages, emojis, etc.).
+ *
+ * @param dst             pointer to destination buffer.
+ * @param dst_size        size of destination buffer.
+ * @param src             pointer to input string.
+ * @param line_width      max number of characters per line.
+ * @param wideglyph_width not used, but is necessary to keep
+ *                        compatibility with word_wrap_wideglyph().
+ * @param max_lines       max lines of destination string.
+ *                        0 means no limit.
+ **/
+void word_wrap(char *dst, size_t dst_size, const char *src,
+      int line_width, int wideglyph_width, unsigned max_lines)
 {
    char *lastspace     = NULL;
    unsigned counter    = 0;
@@ -261,7 +294,43 @@ void word_wrap(char *dst, size_t dst_size, const char *src, int line_width, int
    *dst = '\0';
 }
 
-void word_wrap_wideglyph(char *dst, size_t dst_size, const char *src, int line_width, int wideglyph_width, unsigned max_lines)
+/**
+ * word_wrap_wideglyph:
+ *
+ * Wraps string specified by 'src' to destination buffer
+ * specified by 'dst' and 'dst_size'.
+ * This function assumes that all glyphs in the string
+ * are:
+ * - EITHER 'non-wide' Unicode glyphs, with an on-screen
+ *   pixel width similar to that of regular Latin characters
+ * - OR 'wide' Unicode glyphs (e.g. CJK languages, emojis, etc.)
+ *   with an on-screen pixel width defined by 'wideglyph_width'
+ * Note that wrapping may occur in inappropriate locations
+ * if 'src' string contains 'wide' Unicode characters whose
+ * on-screen pixel width deviates greatly from the set
+ * 'wideglyph_width' value.
+ *
+ * @param dst             pointer to destination buffer.
+ * @param dst_size        size of destination buffer.
+ * @param src             pointer to input string.
+ * @param line_width      max number of characters per line.
+ * @param wideglyph_width effective width of 'wide' Unicode glyphs.
+ *                        the value here is normalised relative to the
+ *                        typical on-screen pixel width of a regular
+ *                        Latin character:
+ *                        - a regular Latin character is defined to
+ *                          have an effective width of 100
+ *                        - wideglyph_width = 100 * (wide_character_pixel_width / latin_character_pixel_width)
+ *                        - e.g. if 'wide' Unicode characters in 'src'
+ *                          have an on-screen pixel width twice that of
+ *                          regular Latin characters, wideglyph_width
+ *                          would be 200
+ * @param max_lines       max lines of destination string.
+ *                        0 means no limit.
+ **/
+void word_wrap_wideglyph(char *dst, size_t dst_size,
+      const char *src, int line_width,
+      int wideglyph_width, unsigned max_lines)
 {
    char *lastspace                   = NULL;
    char *lastwideglyph               = NULL;
@@ -310,7 +379,7 @@ void word_wrap_wideglyph(char *dst, size_t dst_size, const char *src, int line_w
          break;
 
       if (*src == ' ')
-         lastspace        = dst; /* Remember the location of the whitespace */
+         lastspace          = dst; /* Remember the location of the whitespace */
       else if (*src == '\n')
       {
          /* If newlines embedded in the input,
@@ -330,7 +399,7 @@ void word_wrap_wideglyph(char *dst, size_t dst_size, const char *src, int line_w
       {
          /* Remember the location of the first byte
           * whose length as UTF-8 >= 3*/
-         lastwideglyph = dst;
+         lastwideglyph       = dst;
          counter_normalized += additional_counter_normalized;
       }
 
@@ -349,9 +418,9 @@ void word_wrap_wideglyph(char *dst, size_t dst_size, const char *src, int line_w
             /* Insert newline character */
             *lastwideglyph = '\n';
             lines++;
-            src -= dst - lastwideglyph;
-            dst = lastwideglyph + 1;
-            lastwideglyph = NULL;
+            src           -= dst - lastwideglyph;
+            dst            = lastwideglyph + 1;
+            lastwideglyph  = NULL;
 
             /* Early return if remaining src string
              * length is less than line width */
@@ -367,9 +436,9 @@ void word_wrap_wideglyph(char *dst, size_t dst_size, const char *src, int line_w
              * with newline character */
             *lastspace = '\n';
             lines++;
-            src -= dst - lastspace - 1;
-            dst = lastspace + 1;
-            lastspace = NULL;
+            src       -= dst - lastspace - 1;
+            dst        = lastspace + 1;
+            lastspace  = NULL;
 
             /* Early return if remaining src string
              * length is less than line width */
@@ -385,10 +454,13 @@ void word_wrap_wideglyph(char *dst, size_t dst_size, const char *src, int line_w
    *dst = '\0';
 }
 
-/* Splits string into tokens seperated by 'delim'
+/**
+ * string_tokenize:
+ *
+ * Splits string into tokens seperated by @delim
  * > Returned token string must be free()'d
  * > Returns NULL if token is not found
- * > After each call, 'str' is set to the position after the
+ * > After each call, @str is set to the position after the
  *   last found token
  * > Tokens *include* empty strings
  * Usage example:
@@ -401,7 +473,7 @@ void word_wrap_wideglyph(char *dst, size_t dst_size, const char *src, int line_w
  *        free(token);
  *        token = NULL;
  *    }
- */
+ **/
 char* string_tokenize(char **str, const char *delim)
 {
    /* Taken from https://codereview.stackexchange.com/questions/216956/strtok-function-thread-safe-supports-empty-tokens-doesnt-change-string# */
@@ -440,42 +512,53 @@ char* string_tokenize(char **str, const char *delim)
    return token;
 }
 
-/* Removes every instance of character 'c' from 'str' */
+/**
+ * string_remove_all_chars:
+ * @str                : input string (must be non-NULL, otherwise UB)
+ *
+ * Leaf function.
+ *
+ * Removes every instance of character @c from @str
+ **/
 void string_remove_all_chars(char *str, char c)
 {
-   char *read_ptr  = NULL;
-   char *write_ptr = NULL;
-
-   if (string_is_empty(str))
-      return;
-
-   read_ptr  = str;
-   write_ptr = str;
+   char *read_ptr  = str;
+   char *write_ptr = str;
 
    while (*read_ptr != '\0')
    {
       *write_ptr = *read_ptr++;
-      write_ptr += (*write_ptr != c) ? 1 : 0;
+      if (*write_ptr != c)
+         write_ptr++;
    }
 
    *write_ptr = '\0';
 }
 
-/* Replaces every instance of character 'find' in 'str'
- * with character 'replace' */
+/**
+ * string_replace_all_chars:
+ * @str                : input string (must be non-NULL, otherwise UB)
+ * @find               : character to find
+ * @replace            : character to replace @find with
+ *
+ * Replaces every instance of character @find in @str
+ * with character @replace
+ **/
 void string_replace_all_chars(char *str, char find, char replace)
 {
-   if (!string_is_empty(str))
-   {
-      char *str_ptr = str;
-	   while ((str_ptr = strchr(str_ptr, find)))
-		   *str_ptr++ = replace;
-   }
-
+   char *str_ptr = str;
+   while ((str_ptr = strchr(str_ptr, find)))
+      *str_ptr++ = replace;
 }
 
-/* Converts string to unsigned integer.
- * Returns 0 if string is invalid  */
+/**
+ * string_to_unsigned:
+ * @str                : input string
+ *
+ * Converts string to unsigned integer.
+ *
+ * @return 0 if string is invalid, otherwise > 0
+ **/
 unsigned string_to_unsigned(const char *str)
 {
    const char *ptr = NULL;
@@ -492,25 +575,33 @@ unsigned string_to_unsigned(const char *str)
    return (unsigned)strtoul(str, NULL, 10);
 }
 
-/* Converts hexadecimal string to unsigned integer.
+/**
+ * string_hex_to_unsigned:
+ * @str                : input string (must be non-NULL, otherwise UB)
+ *
+ * Converts hexadecimal string to unsigned integer.
  * Handles optional leading '0x'.
- * Returns 0 if string is invalid  */
+ *
+ * @return 0 if string is invalid, otherwise > 0
+ **/
 unsigned string_hex_to_unsigned(const char *str)
 {
    const char *hex_str = str;
    const char *ptr     = NULL;
 
-   if (string_is_empty(str))
-      return 0;
-
    /* Remove leading '0x', if required */
-   if (strlen(str) >= 2)
+   if (str[0] != '\0' && str[1] != '\0')
+   {
       if ( (str[0] == '0') &&
           ((str[1] == 'x') || 
            (str[1] == 'X')))
+      {
          hex_str = str + 2;
-
-   if (string_is_empty(hex_str))
+         if (string_is_empty(hex_str))
+            return 0;
+      }
+   }
+   else
       return 0;
 
    /* Check for valid characters */
@@ -524,7 +615,13 @@ unsigned string_hex_to_unsigned(const char *str)
 }
 
 /**
- * Get the total number of occurrences of a character in the given string.
+ * string_count_occurrences_single_character:
+ *
+ * Leaf function.
+ *
+ * Get the total number of occurrences of character @c in @str.
+ *
+ * @return Total number of occurrences of character @c
  */
 int string_count_occurrences_single_character(const char *str, char c)
 {
@@ -538,8 +635,12 @@ int string_count_occurrences_single_character(const char *str, char c)
 }
 
 /**
- * Replaces all spaces with the given character.
- */
+ * string_replace_whitespace_with_single_character:
+ * 
+ * Leaf function.
+ *
+ * Replaces all spaces with given character @c.
+ **/
 void string_replace_whitespace_with_single_character(char *str, char c)
 {
    for (; *str; str++)
@@ -548,8 +649,12 @@ void string_replace_whitespace_with_single_character(char *str, char c)
 }
 
 /**
+ * string_replace_multi_space_with_single_space:
+ *
+ * Leaf function.
+ *
  * Replaces multiple spaces with a single space in a string.
- */
+ **/
 void string_replace_multi_space_with_single_space(char *str)
 {
    char *str_trimmed  = str;
@@ -568,8 +673,12 @@ void string_replace_multi_space_with_single_space(char *str)
 }
 
 /**
+ * string_remove_all_whitespace:
+ *
+ * Leaf function.
+ *
  * Remove all spaces from the given string.
- */
+ **/
 void string_remove_all_whitespace(char *str_trimmed, const char *str)
 {
    for (; *str; str++)
@@ -589,22 +698,27 @@ int string_index_last_occurance(const char *str, char c)
 }
 
 /**
- * Find the position of a substring in a string.
- */
+ * string_find_index_substring_string:
+ * @str                : input string (must be non-NULL, otherwise UB)
+ * @substr             : substring to find in @str
+ *
+ * Find the position of substring @substr in string @str.
+ **/
 int string_find_index_substring_string(const char *str, const char *substr)
 {
-   if (!string_is_empty(str))
-   {
-      const char *pos = strstr(str, substr);
-
-      if (pos)
-         return pos - str;
-   }
-
+   const char *pos = strstr(str, substr);
+   if (pos)
+      return pos - str;
    return -1;
 }
 
-/* Strips non-ASCII characters from a string. */
+/**
+ * string_copy_only_ascii:
+ *
+ * Leaf function.
+ *
+ * Strips non-ASCII characters from a string.
+ **/
 void string_copy_only_ascii(char *str_stripped, const char *str)
 {
    for (; *str; str++)