4 files changed, 6 insertions, 5 deletions
diff --git a/lib/strnumcmp-in.h b/lib/strnumcmp-in.h
index dccbca539..7e963bc16 100644
--- a/lib/strnumcmp-in.h
+++ b/lib/strnumcmp-in.h
@@ -71,7 +71,7 @@
      if digit return -1, else 0
    return 0 */
 
-static inline int
+static inline int _GL_ATTRIBUTE_PURE
 fraccompare (char const *a, char const *b, char decimal_point)
 {
   if (*a == decimal_point && *b == decimal_point)
@@ -111,7 +111,7 @@ fraccompare (char const *a, char const *b, char decimal_point)
    causes comparisons to act as if there is no decimal point
    character, and likewise for THOUSANDS_SEP.  */
 
-static inline int
+static inline int _GL_ATTRIBUTE_PURE
 numcompare (char const *a, char const *b,
             int decimal_point, int thousands_sep)
 {
diff --git a/lib/strnumcmp.c b/lib/strnumcmp.c
index f130b5836..2dfc28c9e 100644
--- a/lib/strnumcmp.c
+++ b/lib/strnumcmp.c
@@ -23,7 +23,7 @@
 
 /* Externally-visible name for numcompare.  */
 
-int
+int _GL_ATTRIBUTE_PURE
 strnumcmp (char const *a, char const *b,
            int decimal_point, int thousands_sep)
 {
diff --git a/lib/strnumcmp.h b/lib/strnumcmp.h
index 91ad3519b..4deef82bd 100644
--- a/lib/strnumcmp.h
+++ b/lib/strnumcmp.h
@@ -1,2 +1,2 @@
-int strintcmp (char const *, char const *);
+int strintcmp (char const *, char const *) _GL_ATTRIBUTE_PURE;
 int strnumcmp (char const *, char const *, int, int);
diff --git a/lib/xfts.h b/lib/xfts.h
index fc3ba9010..f903f4804 100644
--- a/lib/xfts.h
+++ b/lib/xfts.h
@@ -6,4 +6,5 @@ xfts_open (char * const *, int options,
            int (*) (const FTSENT **, const FTSENT **));
 
 bool
-cycle_warning_required (FTS const *fts, FTSENT const *ent);
+cycle_warning_required (FTS const *fts, FTSENT const *ent)
+  _GL_ATTRIBUTE_PURE;