Add some const decorations to prototypes

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

src/backend/parser/parse_expr.c

@@ -386,7 +386,7 @@ transformExprRecurse(ParseState *pstate, Node *expr)
  * selection from an arbitrary node needs it.)
  */
 static void
-unknown_attribute(ParseState *pstate, Node *relref, char *attname,
+unknown_attribute(ParseState *pstate, Node *relref, const char *attname,
 				  int location)
 {
 	RangeTblEntry *rte;

src/backend/parser/parse_func.c

@@ -39,7 +39,7 @@ static void unify_hypothetical_args(ParseState *pstate,
 						List *fargs, int numAggregatedArgs,
 						Oid *actual_arg_types, Oid *declared_arg_types);
 static Oid	FuncNameAsType(List *funcname);
-static Node *ParseComplexProjection(ParseState *pstate, char *funcname,
+static Node *ParseComplexProjection(ParseState *pstate, const char *funcname,
 					   Node *first_arg, int location);
 
 
@@ -1790,7 +1790,7 @@ FuncNameAsType(List *funcname)
  *	  transformed expression tree.  If not, return NULL.
  */
 static Node *
-ParseComplexProjection(ParseState *pstate, char *funcname, Node *first_arg,
+ParseComplexProjection(ParseState *pstate, const char *funcname, Node *first_arg,
 					   int location)
 {
 	TupleDesc	tupdesc;

src/backend/parser/parse_relation.c

@@ -652,7 +652,7 @@ updateFuzzyAttrMatchState(int fuzzy_rte_penalty,
  * for an approximate match and update fuzzystate accordingly.
  */
 Node *
-scanRTEForColumn(ParseState *pstate, RangeTblEntry *rte, char *colname,
+scanRTEForColumn(ParseState *pstate, RangeTblEntry *rte, const char *colname,
 				 int location, int fuzzy_rte_penalty,
 				 FuzzyAttrMatchState *fuzzystate)
 {
@@ -754,7 +754,7 @@ scanRTEForColumn(ParseState *pstate, RangeTblEntry *rte, char *colname,
  *	  If localonly is true, only names in the innermost query are considered.
  */
 Node *
-colNameToVar(ParseState *pstate, char *colname, bool localonly,
+colNameToVar(ParseState *pstate, const char *colname, bool localonly,
 			 int location)
 {
 	Node	   *result = NULL;
@@ -828,7 +828,7 @@ colNameToVar(ParseState *pstate, char *colname, bool localonly,
  * and 'second' will contain the attribute number for the second match.
  */
 static FuzzyAttrMatchState *
-searchRangeTableForCol(ParseState *pstate, const char *alias, char *colname,
+searchRangeTableForCol(ParseState *pstate, const char *alias, const char *colname,
 					   int location)
 {
 	ParseState *orig_pstate = pstate;
@@ -3248,7 +3248,7 @@ errorMissingRTE(ParseState *pstate, RangeVar *relation)
  */
 void
 errorMissingColumn(ParseState *pstate,
-				   char *relname, char *colname, int location)
+				   const char *relname, const char *colname, int location)
 {
 	FuzzyAttrMatchState *state;
 	char	   *closestfirst = NULL;

src/backend/parser/parse_target.c

@@ -455,7 +455,7 @@ Expr *
 transformAssignedExpr(ParseState *pstate,
 					  Expr *expr,
 					  ParseExprKind exprKind,
-					  char *colname,
+					  const char *colname,
 					  int attrno,
 					  List *indirection,
 					  int location)