Mark pure functions with attribute pure

1 files changed, 4 insertions, 4 deletions

diff --git a/include/string.h b/include/string.h
index c77d387b..c31b4292 100644
--- a/include/string.h
+++ b/include/string.h
@@ -32,7 +32,7 @@ extern void *memcpy (void *dest, const void *src, size_t n);
 
 extern void *memmove (void *dest, const void *src, size_t n);
 
-extern int memcmp (const void *s1, const void *s2, size_t n);
+extern int memcmp (const void *s1, const void *s2, size_t n) __attribute__ ((pure));
 
 extern void *memset (void *s, int c, size_t n);
 
@@ -46,11 +46,11 @@ extern char *strrchr (const char *s, int c);
 
 extern char *strsep (char **strp, const char *delim);
 
-extern int strcmp (const char *s1, const char *s2);
+extern int strcmp (const char *s1, const char *s2) __attribute__ ((pure));
 
-extern int strncmp (const char *s1, const char *s2, size_t n);
+extern int strncmp (const char *s1, const char *s2, size_t n) __attribute__ ((pure));
 
-extern size_t strlen (const char *s);
+extern size_t strlen (const char *s) __attribute__ ((pure));
 
 extern char *strstr(const char *haystack, const char *needle);