Add some const decorations to prototypes

Reviewed-by: Fabien COELHO <coelho@cri.ensmp.fr>

contrib/dict_xsyn/dict_xsyn.c

@@ -70,7 +70,7 @@ compare_syn(const void *a, const void *b)
 }
 
 static void
-read_dictionary(DictSyn *d, char *filename)
+read_dictionary(DictSyn *d, const char *filename)
 {
 	char	   *real_filename = get_tsearch_config_filename(filename, "rules");
 	tsearch_readline_state trst;

contrib/fuzzystrmatch/dmetaphone.c

@@ -232,7 +232,7 @@ metastring;
  */
 
 static metastring *
-NewMetaString(char *init_str)
+NewMetaString(const char *init_str)
 {
 	metastring *s;
 	char		empty_string[] = "";
@@ -375,7 +375,7 @@ StringAt(metastring *s, int start, int length,...)
 
 
 static void
-MetaphAdd(metastring *s, char *new_str)
+MetaphAdd(metastring *s, const char *new_str)
 {
 	int			add_length;
 

contrib/pgcrypto/pgcrypto.c

@@ -47,7 +47,7 @@ PG_MODULE_MAGIC;
 /* private stuff */
 
 typedef int (*PFN) (const char *name, void **res);
-static void *find_provider(text *name, PFN pf, char *desc, int silent);
+static void *find_provider(text *name, PFN pf, const char *desc, int silent);
 
 /* SQL function: hash(bytea, text) returns bytea */
 PG_FUNCTION_INFO_V1(pg_digest);
@@ -474,7 +474,7 @@ pg_random_uuid(PG_FUNCTION_ARGS)
 static void *
 find_provider(text *name,
 			  PFN provider_lookup,
-			  char *desc, int silent)
+			  const char *desc, int silent)
 {
 	void	   *res;
 	char	   *buf;

contrib/seg/seg.c

@@ -1052,9 +1052,9 @@ restore(char *result, float val, int n)
  * a floating point number
  */
 int
-significant_digits(char *s)
+significant_digits(const char *s)
 {
-	char	   *p = s;
+	const char *p = s;
 	int			n,
 				c,
 				zeroes;

contrib/seg/segdata.h

@@ -12,7 +12,7 @@ typedef struct SEG
 } SEG;
 
 /* in seg.c */
-extern int	significant_digits(char *str);
+extern int	significant_digits(const char *str);
 
 /* in segscan.l */
 extern int	seg_yylex(void);

contrib/seg/segparse.y

@@ -21,7 +21,7 @@
 #define YYMALLOC palloc
 #define YYFREE   pfree
 
-static float seg_atof(char *value);
+static float seg_atof(const char *value);
 
 static char strbuf[25] = {
 	'0', '0', '0', '0', '0',
@@ -151,7 +151,7 @@ deviation: SEGFLOAT
 
 
 static float
-seg_atof(char *value)
+seg_atof(const char *value)
 {
 	Datum datum;
 

contrib/unaccent/unaccent.c

@@ -90,7 +90,7 @@ placeChar(TrieChar *node, const unsigned char *str, int lenstr,
  * Function converts UTF8-encoded file into current encoding.
  */
 static TrieChar *
-initTrie(char *filename)
+initTrie(const char *filename)
 {
 	TrieChar   *volatile rootTrie = NULL;
 	MemoryContext ccxt = CurrentMemoryContext;

contrib/uuid-ossp/uuid-ossp.c

@@ -253,7 +253,7 @@ uuid_generate_v35_internal(int mode, pg_uuid_t *ns, text *name)
 #else							/* !HAVE_UUID_OSSP */
 
 static Datum
-uuid_generate_internal(int v, unsigned char *ns, char *ptr, int len)
+uuid_generate_internal(int v, unsigned char *ns, const char *ptr, int len)
 {
 	char		strbuf[40];