mem: mark all functions as PURE

This might allow compilers that support the anotation to make better
choices when optimizing, and all these functions meet the requirements
for being marked pure.
Signed-off-by: Cody P Schafer <dev@codyps.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

ccan/mem/_info

@@ -18,6 +18,7 @@ int main(int argc, char *argv[])
 		return 1;
 
 	if (strcmp(argv[1], "depends") == 0) {
+		printf("ccan/compiler");
 		return 0;
 	}
 

ccan/mem/mem.h

@@ -3,16 +3,19 @@
 #define CCAN_MEM_H
 
 #include "config.h"
+#include <ccan/compiler/compiler.h>
 
 #include <string.h>
 #include <stdbool.h>
 
 #if !HAVE_MEMMEM
+PURE_FUNCTION
 void *memmem(const void *haystack, size_t haystacklen,
 	     const void *needle, size_t needlelen);
 #endif
 
 #if !HAVE_MEMRCHR
+PURE_FUNCTION
 void *memrchr(const void *s, int c, size_t n);
 #endif
 
@@ -37,6 +40,7 @@ void *memrchr(const void *s, int c, size_t n);
  *	}
  *
  */
+PURE_FUNCTION
 void *mempbrkm(const void *data, size_t len, const void *accept, size_t accept_len);
 
 /**
@@ -57,6 +61,7 @@ void *mempbrkm(const void *data, size_t len, const void *accept, size_t accept_l
  *		printf("Nada\n");
  *	}
  */
+PURE_FUNCTION
 static inline char *mempbrk(const void *data, size_t len, const char *accept)
 {
 	return mempbrkm(data, len, accept, strlen(accept));
@@ -81,6 +86,7 @@ static inline char *mempbrk(const void *data, size_t len, const char *accept)
  *		printf("Found %c after trimming spaces\n", *r);
  *	}
  */
+PURE_FUNCTION
 void *memcchr(void const *data, int c, size_t data_len);
 
 /**
@@ -95,6 +101,7 @@ void *memcchr(void const *data, int c, size_t data_len);
  *		printf("memory blocks are the same!\n");
  *	}
  */
+PURE_FUNCTION
 static inline bool memeq(const void *a, size_t al, const void *b, size_t bl)
 {
 	return al == bl && !memcmp(a, b, bl);
@@ -114,6 +121,7 @@ static inline bool memeq(const void *a, size_t al, const void *b, size_t bl)
  *		printf("somebytes starts with otherbytes!\n");
  *	}
  */
+PURE_FUNCTION
 static inline bool memstarts(void const *data, size_t data_len,
 		void const *prefix, size_t prefix_len)
 {
@@ -135,6 +143,7 @@ static inline bool memstarts(void const *data, size_t data_len,
  *		printf("somebytes == 'foo'!\n");
  *	}
  */
+PURE_FUNCTION
 static inline bool memeqstr(const void *data, size_t length, const char *string)
 {
 	return memeq(data, length, string, strlen(string));
@@ -151,6 +160,7 @@ static inline bool memeqstr(const void *data, size_t length, const char *string)
  *		printf("somebytes starts with 'It'\n");
  *	}
  */
+PURE_FUNCTION
 static inline bool memstarts_str(const void *a, size_t al, const char *s)
 {
 	return memstarts(a, al, s, strlen(s));
@@ -166,6 +176,7 @@ static inline bool memstarts_str(const void *a, size_t al, const char *s)
  * Returns true if @suffix appears as a substring at the end of @s,
  * false otherwise.
  */
+PURE_FUNCTION
 static inline bool memends(const void *s, size_t s_len, const void *suffix, size_t suffix_len)
 {
 	return (s_len >= suffix_len) && (memcmp((const char *)s + s_len - suffix_len,