build: add const and pure attributes, per gcc recommendation

* src/mkid.c (ceil_log_8, ceil_log_2): Add "const" attribute.
(token_hash_1, token_hash_2): Add "pure" attribute.
(token_hash_cmp, token_qsort_cmp): Likewise.
(count_vec_size, count_buf_size): Likewise.

* libidu/idu-hash.c (round_up_2): Add "const" attribute.
* libidu/scanners.h (get_language): Add "pure" attribute.
* libidu/idfile.h (token_flags): Likewise.
(token_count): Likewise.
(member_file_qsort_compare): Likewise.
(tree8_count_levels): Add "const" attribute.
* libidu/walker.c (symlink_ancestry): Add "pure" attribute.
(links_depth): Likewise.
(file_link_hash_1): Likewise.
(vector_length): Likewise.
(file_link_hash_compare): Likewise.
(string_in_vector): Likewise.
* src/lid.c (vector_cardinality, get_radix, dtoi, otoi): Likewise.
(is_regexp): Likewise.
(vector_length): Remove forward decl and move function definition
to precede first use.

1 files changed, 14 insertions, 15 deletions

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;