4 files changed, 25 insertions, 23 deletions
diff --git a/libidu/idfile.h b/libidu/idfile.h
index fe531db..739819d 100644
--- a/libidu/idfile.h
+++ b/libidu/idfile.h
@@ -144,9 +144,10 @@ extern struct hash_table dev_ino_table;
 /* token flags (struct token is defined in scanners.h) */
 
 #define token_string(buf) (buf)
-extern unsigned int token_flags (char const *buf);
-extern unsigned short token_count (char const *buf);
-extern unsigned char const *token_hits_addr (char const *buf);
+extern unsigned int token_flags (char const *buf) _GL_ATTRIBUTE_PURE;
+extern unsigned short token_count (char const *buf) _GL_ATTRIBUTE_PURE;
+extern unsigned char const *token_hits_addr (char const *buf)
+  _GL_ATTRIBUTE_PURE;
 
 #define MAYBE_RETURN_PREFIX_MATCH(arg, str, val) do { \
     char const *_s_ = (str); \
@@ -187,7 +188,8 @@ extern struct file_link **deserialize_file_links (struct idhead *idhp);
 extern void serialize_file_links (struct idhead *idhp);
 
 extern void mark_member_file_links (struct idhead *idhp);
-extern int member_file_qsort_compare (void const *x, void const *y);
+extern int member_file_qsort_compare (void const *x, void const *y)
+  _GL_ATTRIBUTE_PURE;
 extern struct file_link *parse_file_name (char *file_name, struct file_link *relative_dir_link);
 extern void print_filenames (struct file_link **flinkv, enum separator_style separator_style);
 extern enum separator_style parse_separator_style (char const *arg);
@@ -202,11 +204,11 @@ extern char *absolute_file_name (char *buffer, struct file_link const *flink);
 extern char *maybe_relative_file_name (char *buffer, struct file_link const *to_link, struct file_link const *from_link);
 extern char const *locate_id_file_name (char const *arg);
 
-extern int tree8_count_levels (unsigned int cardinality);
+extern int tree8_count_levels (unsigned int cardinality) _GL_ATTRIBUTE_CONST;
 extern int gets_past_00 (char *tok, FILE *input_FILE);
 extern int skip_past_00 (FILE *input_FILE);
 
-extern int links_depth (struct file_link const *flink);
+extern int links_depth (struct file_link const *flink) _GL_ATTRIBUTE_PURE;
 
 #if HAVE_LINK
 
diff --git a/libidu/idu-hash.c b/libidu/idu-hash.c
index 58b6d3d..3d55c64 100644
--- a/libidu/idu-hash.c
+++ b/libidu/idu-hash.c
@@ -296,7 +296,7 @@ hash_dump (struct hash_table const *ht, void **vector_0, qsort_cmp_t compare)
 
 /* Round a given number up to the nearest power of 2. */
 
-static unsigned long
+static unsigned long _GL_ATTRIBUTE_CONST
 round_up_2 (unsigned long rough)
 {
   int round;
diff --git a/libidu/scanners.h b/libidu/scanners.h
index cc0dad0..b20ec3c 100644
--- a/libidu/scanners.h
+++ b/libidu/scanners.h
@@ -63,7 +63,8 @@ struct lang_args
 extern void language_help_me (void);
 extern void language_getopt (void);
 extern void language_save_arg (char *arg);
-extern struct language *get_language (char const *lang_name);
+extern struct language *get_language (char const *lang_name)
+  _GL_ATTRIBUTE_PURE;
 extern void parse_language_map (char const *file_name);
 extern void set_default_language (char const *lang_name);
 
diff --git a/libidu/walker.c b/libidu/walker.c
index 02e3d65..e268f35 100644
--- a/libidu/walker.c
+++ b/libidu/walker.c
@@ -59,7 +59,6 @@ static struct file_link *make_link_from_string (char const *name,
 static int lang_wanted (char const *lang_name);
 static char **append_strings_to_vector (char **vector_0, char *string,
 					char const *delimiter_class);
-static int vector_length (char **vector);
 static int string_in_vector (char const *string, char **vector);
 static int same_as_dot (char const *cwd);
 static struct file_link const
@@ -365,7 +364,7 @@ find_alias_link (struct file_link *flink, struct stat *stp)
    directory.  PATH_MAX is considered an infinite distance (e.g.,
    there are no symlinks between `flink' and the root).  */
 
-static int
+static int _GL_ATTRIBUTE_PURE
 symlink_ancestry (struct file_link *flink)
 {
   int ancestry = 0;
@@ -506,6 +505,15 @@ exclude_languages (char *lang_names)
   langs_excluded = append_strings_to_vector (langs_excluded, lang_names, white_space);
 }
 
+static int _GL_ATTRIBUTE_PURE
+vector_length (char **vector)
+{
+  int length = 0;
+  while (*vector++)
+    length++;
+  return length;
+}
+
 static char **
 append_strings_to_vector (char **vector_0, char *string,
 			  char const *delimiter_class)
@@ -527,16 +535,7 @@ append_strings_to_vector (char **vector_0, char *string,
   return xnrealloc (vector_0, vector - vector_0, sizeof *vector_0);
 }
 
-static int
-vector_length (char **vector)
-{
-  int length = 0;
-  while (*vector++)
-    length++;
-  return length;
-}
-
-static int
+static int _GL_ATTRIBUTE_PURE
 string_in_vector (char const *string, char **vector)
 {
   while (*vector)
@@ -1052,7 +1051,7 @@ member_file_qsort_compare (void const *x, void const *y)
 /****************************************************************************/
 /* Hash stuff for `struct file_link'.  */
 
-static unsigned long
+static unsigned long _GL_ATTRIBUTE_PURE
 file_link_hash_1 (void const *key)
 {
   unsigned long result = 0;
@@ -1063,7 +1062,7 @@ file_link_hash_1 (void const *key)
   return result;
 }
 
-static unsigned long
+static unsigned long _GL_ATTRIBUTE_PURE
 file_link_hash_2 (void const *key)
 {
   unsigned long result = 0;
@@ -1074,7 +1073,7 @@ file_link_hash_2 (void const *key)
   return result;
 }
 
-static int
+static int _GL_ATTRIBUTE_PURE
 file_link_hash_compare (void const *x, void const *y)
 {
   int result;