Make better use of existing enums in plpgsql

plpgsql.h defines a number of enums, but most of the code passes them
around as ints.  Update structs and function prototypes to take enum
types instead.  This clarifies the struct definitions in plpgsql.h in
particular.
Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com>

src/pl/plpgsql/src/pl_comp.c

@@ -93,7 +93,7 @@ static PLpgSQL_function *do_compile(FunctionCallInfo fcinfo,
 		   PLpgSQL_func_hashkey *hashkey,
 		   bool forValidator);
 static void plpgsql_compile_error_callback(void *arg);
-static void add_parameter_name(int itemtype, int itemno, const char *name);
+static void add_parameter_name(PLpgSQL_nsitem_type itemtype, int itemno, const char *name);
 static void add_dummy_return(PLpgSQL_function *function);
 static Node *plpgsql_pre_column_ref(ParseState *pstate, ColumnRef *cref);
 static Node *plpgsql_post_column_ref(ParseState *pstate, ColumnRef *cref, Node *var);
@@ -410,7 +410,7 @@ do_compile(FunctionCallInfo fcinfo,
 				char		argmode = argmodes ? argmodes[i] : PROARGMODE_IN;
 				PLpgSQL_type *argdtype;
 				PLpgSQL_variable *argvariable;
-				int			argitemtype;
+				PLpgSQL_nsitem_type argitemtype;
 
 				/* Create $n name for variable */
 				snprintf(buf, sizeof(buf), "$%d", i + 1);
@@ -946,7 +946,7 @@ plpgsql_compile_error_callback(void *arg)
  * Add a name for a function parameter to the function's namespace
  */
 static void
-add_parameter_name(int itemtype, int itemno, const char *name)
+add_parameter_name(PLpgSQL_nsitem_type itemtype, int itemno, const char *name)
 {
 	/*
 	 * Before adding the name, check for duplicates.  We need this even though

src/pl/plpgsql/src/pl_exec.c

@@ -1557,7 +1557,7 @@ exec_stmt(PLpgSQL_execstate *estate, PLpgSQL_stmt *stmt)
 
 	CHECK_FOR_INTERRUPTS();
 
-	switch ((enum PLpgSQL_stmt_types) stmt->cmd_type)
+	switch (stmt->cmd_type)
 	{
 		case PLPGSQL_STMT_BLOCK:
 			rc = exec_stmt_block(estate, (PLpgSQL_stmt_block *) stmt);

src/pl/plpgsql/src/pl_funcs.c

@@ -51,7 +51,7 @@ plpgsql_ns_init(void)
  * ----------
  */
 void
-plpgsql_ns_push(const char *label, enum PLpgSQL_label_types label_type)
+plpgsql_ns_push(const char *label, PLpgSQL_label_type label_type)
 {
 	if (label == NULL)
 		label = "";
@@ -89,7 +89,7 @@ plpgsql_ns_top(void)
  * ----------
  */
 void
-plpgsql_ns_additem(int itemtype, int itemno, const char *name)
+plpgsql_ns_additem(PLpgSQL_nsitem_type itemtype, int itemno, const char *name)
 {
 	PLpgSQL_nsitem *nse;
 
@@ -231,7 +231,7 @@ plpgsql_ns_find_nearest_loop(PLpgSQL_nsitem *ns_cur)
 const char *
 plpgsql_stmt_typename(PLpgSQL_stmt *stmt)
 {
-	switch ((enum PLpgSQL_stmt_types) stmt->cmd_type)
+	switch (stmt->cmd_type)
 	{
 		case PLPGSQL_STMT_BLOCK:
 			return _("statement block");
@@ -291,7 +291,7 @@ plpgsql_stmt_typename(PLpgSQL_stmt *stmt)
  * GET DIAGNOSTICS item name as a string, for use in error messages etc.
  */
 const char *
-plpgsql_getdiag_kindname(int kind)
+plpgsql_getdiag_kindname(PLpgSQL_getdiag_kind kind)
 {
 	switch (kind)
 	{
@@ -367,7 +367,7 @@ static void free_expr(PLpgSQL_expr *expr);
 static void
 free_stmt(PLpgSQL_stmt *stmt)
 {
-	switch ((enum PLpgSQL_stmt_types) stmt->cmd_type)
+	switch (stmt->cmd_type)
 	{
 		case PLPGSQL_STMT_BLOCK:
 			free_block((PLpgSQL_stmt_block *) stmt);
@@ -791,7 +791,7 @@ static void
 dump_stmt(PLpgSQL_stmt *stmt)
 {
 	printf("%3d:", stmt->lineno);
-	switch ((enum PLpgSQL_stmt_types) stmt->cmd_type)
+	switch (stmt->cmd_type)
 	{
 		case PLPGSQL_STMT_BLOCK:
 			dump_block((PLpgSQL_stmt_block *) stmt);

src/pl/plpgsql/src/plpgsql.h

@@ -37,28 +37,28 @@
 /*
  * Compiler's namespace item types
  */
-enum
+typedef enum PLpgSQL_nsitem_type
 {
 	PLPGSQL_NSTYPE_LABEL,
 	PLPGSQL_NSTYPE_VAR,
 	PLPGSQL_NSTYPE_ROW,
 	PLPGSQL_NSTYPE_REC
-};
+} PLpgSQL_nsitem_type;
 
 /*
  * A PLPGSQL_NSTYPE_LABEL stack entry must be one of these types
  */
-enum PLpgSQL_label_types
+typedef enum PLpgSQL_label_type
 {
 	PLPGSQL_LABEL_BLOCK,		/* DECLARE/BEGIN block */
 	PLPGSQL_LABEL_LOOP,			/* looping construct */
 	PLPGSQL_LABEL_OTHER			/* anything else */
-};
+} PLpgSQL_label_type;
 
 /*
  * Datum array node types
  */
-enum
+typedef enum PLpgSQL_datum_type
 {
 	PLPGSQL_DTYPE_VAR,
 	PLPGSQL_DTYPE_ROW,
@@ -66,23 +66,23 @@ enum
 	PLPGSQL_DTYPE_RECFIELD,
 	PLPGSQL_DTYPE_ARRAYELEM,
 	PLPGSQL_DTYPE_EXPR
-};
+} PLpgSQL_datum_type;
 
 /*
  * Variants distinguished in PLpgSQL_type structs
  */
-enum
+typedef enum PLpgSQL_type_type
 {
 	PLPGSQL_TTYPE_SCALAR,		/* scalar types and domains */
 	PLPGSQL_TTYPE_ROW,			/* composite types */
 	PLPGSQL_TTYPE_REC,			/* RECORD pseudotype */
 	PLPGSQL_TTYPE_PSEUDO		/* other pseudotypes */
-};
+} PLpgSQL_type_type;
 
 /*
  * Execution tree node types
  */
-enum PLpgSQL_stmt_types
+typedef enum PLpgSQL_stmt_type
 {
 	PLPGSQL_STMT_BLOCK,
 	PLPGSQL_STMT_ASSIGN,
@@ -108,7 +108,7 @@ enum PLpgSQL_stmt_types
 	PLPGSQL_STMT_FETCH,
 	PLPGSQL_STMT_CLOSE,
 	PLPGSQL_STMT_PERFORM
-};
+} PLpgSQL_stmt_type;
 
 /*
  * Execution node return codes
@@ -124,7 +124,7 @@ enum
 /*
  * GET DIAGNOSTICS information items
  */
-enum
+typedef enum PLpgSQL_getdiag_kind
 {
 	PLPGSQL_GETDIAG_ROW_COUNT,
 	PLPGSQL_GETDIAG_RESULT_OID,
@@ -139,12 +139,12 @@ enum
 	PLPGSQL_GETDIAG_MESSAGE_TEXT,
 	PLPGSQL_GETDIAG_TABLE_NAME,
 	PLPGSQL_GETDIAG_SCHEMA_NAME
-};
+} PLpgSQL_getdiag_kind;
 
 /*
  * RAISE statement options
  */
-enum
+typedef enum PLpgSQL_raise_option_type
 {
 	PLPGSQL_RAISEOPTION_ERRCODE,
 	PLPGSQL_RAISEOPTION_MESSAGE,
@@ -155,12 +155,12 @@ enum
 	PLPGSQL_RAISEOPTION_DATATYPE,
 	PLPGSQL_RAISEOPTION_TABLE,
 	PLPGSQL_RAISEOPTION_SCHEMA
-};
+} PLpgSQL_raise_option_type;
 
 /*
  * Behavioral modes for plpgsql variable resolution
  */
-typedef enum
+typedef enum PLpgSQL_resolve_option
 {
 	PLPGSQL_RESOLVE_ERROR,		/* throw error if ambiguous */
 	PLPGSQL_RESOLVE_VARIABLE,	/* prefer plpgsql var to table column */
@@ -179,7 +179,7 @@ typedef struct PLpgSQL_type
 {
 	char	   *typname;		/* (simple) name of the type */
 	Oid			typoid;			/* OID of the data type */
-	int			ttype;			/* PLPGSQL_TTYPE_ code */
+	PLpgSQL_type_type ttype;	/* PLPGSQL_TTYPE_ code */
 	int16		typlen;			/* stuff copied from its pg_type entry */
 	bool		typbyval;
 	char		typtype;
@@ -197,7 +197,7 @@ typedef struct PLpgSQL_type
  */
 typedef struct PLpgSQL_datum
 {
-	int			dtype;
+	PLpgSQL_datum_type dtype;
 	int			dno;
 } PLpgSQL_datum;
 
@@ -209,7 +209,7 @@ typedef struct PLpgSQL_datum
  */
 typedef struct PLpgSQL_variable
 {
-	int			dtype;
+	PLpgSQL_datum_type dtype;
 	int			dno;
 	char	   *refname;
 	int			lineno;
@@ -220,7 +220,7 @@ typedef struct PLpgSQL_variable
  */
 typedef struct PLpgSQL_expr
 {
-	int			dtype;
+	PLpgSQL_datum_type dtype;
 	int			dno;
 	char	   *query;
 	SPIPlanPtr	plan;
@@ -255,7 +255,7 @@ typedef struct PLpgSQL_expr
  */
 typedef struct PLpgSQL_var
 {
-	int			dtype;
+	PLpgSQL_datum_type dtype;
 	int			dno;
 	char	   *refname;
 	int			lineno;
@@ -278,7 +278,7 @@ typedef struct PLpgSQL_var
  */
 typedef struct PLpgSQL_row
 {
-	int			dtype;
+	PLpgSQL_datum_type dtype;
 	int			dno;
 	char	   *refname;
 	int			lineno;
@@ -301,7 +301,7 @@ typedef struct PLpgSQL_row
  */
 typedef struct PLpgSQL_rec
 {
-	int			dtype;
+	PLpgSQL_datum_type dtype;
 	int			dno;
 	char	   *refname;
 	int			lineno;
@@ -317,7 +317,7 @@ typedef struct PLpgSQL_rec
  */
 typedef struct PLpgSQL_recfield
 {
-	int			dtype;
+	PLpgSQL_datum_type dtype;
 	int			dno;
 	char	   *fieldname;
 	int			recparentno;	/* dno of parent record */
@@ -328,7 +328,7 @@ typedef struct PLpgSQL_recfield
  */
 typedef struct PLpgSQL_arrayelem
 {
-	int			dtype;
+	PLpgSQL_datum_type dtype;
 	int			dno;
 	PLpgSQL_expr *subscript;
 	int			arrayparentno;	/* dno of parent array variable */
@@ -350,9 +350,9 @@ typedef struct PLpgSQL_arrayelem
  */
 typedef struct PLpgSQL_nsitem
 {
-	int			itemtype;
+	PLpgSQL_nsitem_type itemtype;
 	/*
-	 * For labels, itemno is a value of enum PLpgSQL_label_types. For other
+	 * For labels, itemno is a value of enum PLpgSQL_label_type. For other
 	 * itemtypes, itemno is the associated PLpgSQL_datum's dno.
 	 */
 	int			itemno;
@@ -365,7 +365,7 @@ typedef struct PLpgSQL_nsitem
  */
 typedef struct PLpgSQL_stmt
 {
-	int			cmd_type;
+	PLpgSQL_stmt_type cmd_type;
 	int			lineno;
 } PLpgSQL_stmt;
 
@@ -404,7 +404,7 @@ typedef struct PLpgSQL_exception
  */
 typedef struct PLpgSQL_stmt_block
 {
-	int			cmd_type;
+	PLpgSQL_stmt_type cmd_type;
 	int			lineno;
 	char	   *label;
 	List	   *body;			/* List of statements */
@@ -418,7 +418,7 @@ typedef struct PLpgSQL_stmt_block
  */
 typedef struct PLpgSQL_stmt_assign
 {
-	int			cmd_type;
+	PLpgSQL_stmt_type cmd_type;
 	int			lineno;
 	int			varno;
 	PLpgSQL_expr *expr;
@@ -429,7 +429,7 @@ typedef struct PLpgSQL_stmt_assign
  */
 typedef struct PLpgSQL_stmt_perform
 {
-	int			cmd_type;
+	PLpgSQL_stmt_type cmd_type;
 	int			lineno;
 	PLpgSQL_expr *expr;
 } PLpgSQL_stmt_perform;
@@ -439,7 +439,7 @@ typedef struct PLpgSQL_stmt_perform
  */
 typedef struct PLpgSQL_diag_item
 {
-	int			kind;			/* id for diagnostic value desired */
+	PLpgSQL_getdiag_kind kind;	/* id for diagnostic value desired */
 	int			target;			/* where to assign it */
 } PLpgSQL_diag_item;
 
@@ -448,7 +448,7 @@ typedef struct PLpgSQL_diag_item
  */
 typedef struct PLpgSQL_stmt_getdiag
 {
-	int			cmd_type;
+	PLpgSQL_stmt_type cmd_type;
 	int			lineno;
 	bool		is_stacked;		/* STACKED or CURRENT diagnostics area? */
 	List	   *diag_items;		/* List of PLpgSQL_diag_item */
@@ -459,7 +459,7 @@ typedef struct PLpgSQL_stmt_getdiag
  */
 typedef struct PLpgSQL_stmt_if
 {
-	int			cmd_type;
+	PLpgSQL_stmt_type cmd_type;
 	int			lineno;
 	PLpgSQL_expr *cond;			/* boolean expression for THEN */
 	List	   *then_body;		/* List of statements */
@@ -482,7 +482,7 @@ typedef struct PLpgSQL_if_elsif
  */
 typedef struct PLpgSQL_stmt_case
 {
-	int			cmd_type;
+	PLpgSQL_stmt_type cmd_type;
 	int			lineno;
 	PLpgSQL_expr *t_expr;		/* test expression, or NULL if none */
 	int			t_varno;		/* var to store test expression value into */
@@ -506,7 +506,7 @@ typedef struct PLpgSQL_case_when
  */
 typedef struct PLpgSQL_stmt_loop
 {
-	int			cmd_type;
+	PLpgSQL_stmt_type cmd_type;
 	int			lineno;
 	char	   *label;
 	List	   *body;			/* List of statements */
@@ -517,7 +517,7 @@ typedef struct PLpgSQL_stmt_loop
  */
 typedef struct PLpgSQL_stmt_while
 {
-	int			cmd_type;
+	PLpgSQL_stmt_type cmd_type;
 	int			lineno;
 	char	   *label;
 	PLpgSQL_expr *cond;
@@ -529,7 +529,7 @@ typedef struct PLpgSQL_stmt_while
  */
 typedef struct PLpgSQL_stmt_fori
 {
-	int			cmd_type;
+	PLpgSQL_stmt_type cmd_type;
 	int			lineno;
 	char	   *label;
 	PLpgSQL_var *var;
@@ -547,7 +547,7 @@ typedef struct PLpgSQL_stmt_fori
  */
 typedef struct PLpgSQL_stmt_forq
 {
-	int			cmd_type;
+	PLpgSQL_stmt_type cmd_type;
 	int			lineno;
 	char	   *label;
 	PLpgSQL_rec *rec;
@@ -560,7 +560,7 @@ typedef struct PLpgSQL_stmt_forq
  */
 typedef struct PLpgSQL_stmt_fors
 {
-	int			cmd_type;
+	PLpgSQL_stmt_type cmd_type;
 	int			lineno;
 	char	   *label;
 	PLpgSQL_rec *rec;
@@ -575,7 +575,7 @@ typedef struct PLpgSQL_stmt_fors
  */
 typedef struct PLpgSQL_stmt_forc
 {
-	int			cmd_type;
+	PLpgSQL_stmt_type cmd_type;
 	int			lineno;
 	char	   *label;
 	PLpgSQL_rec *rec;
@@ -591,7 +591,7 @@ typedef struct PLpgSQL_stmt_forc
  */
 typedef struct PLpgSQL_stmt_dynfors
 {
-	int			cmd_type;
+	PLpgSQL_stmt_type cmd_type;
 	int			lineno;
 	char	   *label;
 	PLpgSQL_rec *rec;
@@ -607,7 +607,7 @@ typedef struct PLpgSQL_stmt_dynfors
  */
 typedef struct PLpgSQL_stmt_foreach_a
 {
-	int			cmd_type;
+	PLpgSQL_stmt_type cmd_type;
 	int			lineno;
 	char	   *label;
 	int			varno;			/* loop target variable */
@@ -621,7 +621,7 @@ typedef struct PLpgSQL_stmt_foreach_a
  */
 typedef struct PLpgSQL_stmt_open
 {
-	int			cmd_type;
+	PLpgSQL_stmt_type cmd_type;
 	int			lineno;
 	int			curvar;
 	int			cursor_options;
@@ -637,7 +637,7 @@ typedef struct PLpgSQL_stmt_open
  */
 typedef struct PLpgSQL_stmt_fetch
 {
-	int			cmd_type;
+	PLpgSQL_stmt_type cmd_type;
 	int			lineno;
 	PLpgSQL_rec *rec;			/* target, as record or row */
 	PLpgSQL_row *row;
@@ -654,7 +654,7 @@ typedef struct PLpgSQL_stmt_fetch
  */
 typedef struct PLpgSQL_stmt_close
 {
-	int			cmd_type;
+	PLpgSQL_stmt_type cmd_type;
 	int			lineno;
 	int			curvar;
 } PLpgSQL_stmt_close;
@@ -664,7 +664,7 @@ typedef struct PLpgSQL_stmt_close
  */
 typedef struct PLpgSQL_stmt_exit
 {
-	int			cmd_type;
+	PLpgSQL_stmt_type cmd_type;
 	int			lineno;
 	bool		is_exit;		/* Is this an exit or a continue? */
 	char	   *label;			/* NULL if it's an unlabelled EXIT/CONTINUE */
@@ -676,7 +676,7 @@ typedef struct PLpgSQL_stmt_exit
  */
 typedef struct PLpgSQL_stmt_return
 {
-	int			cmd_type;
+	PLpgSQL_stmt_type cmd_type;
 	int			lineno;
 	PLpgSQL_expr *expr;
 	int			retvarno;
@@ -687,7 +687,7 @@ typedef struct PLpgSQL_stmt_return
  */
 typedef struct PLpgSQL_stmt_return_next
 {
-	int			cmd_type;
+	PLpgSQL_stmt_type cmd_type;
 	int			lineno;
 	PLpgSQL_expr *expr;
 	int			retvarno;
@@ -698,7 +698,7 @@ typedef struct PLpgSQL_stmt_return_next
  */
 typedef struct PLpgSQL_stmt_return_query
 {
-	int			cmd_type;
+	PLpgSQL_stmt_type cmd_type;
 	int			lineno;
 	PLpgSQL_expr *query;		/* if static query */
 	PLpgSQL_expr *dynquery;		/* if dynamic query (RETURN QUERY EXECUTE) */
@@ -710,7 +710,7 @@ typedef struct PLpgSQL_stmt_return_query
  */
 typedef struct PLpgSQL_stmt_raise
 {
-	int			cmd_type;
+	PLpgSQL_stmt_type cmd_type;
 	int			lineno;
 	int			elog_level;
 	char	   *condname;		/* condition name, SQLSTATE, or NULL */
@@ -724,7 +724,7 @@ typedef struct PLpgSQL_stmt_raise
  */
 typedef struct PLpgSQL_raise_option
 {
-	int			opt_type;
+	PLpgSQL_raise_option_type opt_type;
 	PLpgSQL_expr *expr;
 } PLpgSQL_raise_option;
 
@@ -733,7 +733,7 @@ typedef struct PLpgSQL_raise_option
  */
 typedef struct PLpgSQL_stmt_assert
 {
-	int			cmd_type;
+	PLpgSQL_stmt_type cmd_type;
 	int			lineno;
 	PLpgSQL_expr *cond;
 	PLpgSQL_expr *message;
@@ -744,7 +744,7 @@ typedef struct PLpgSQL_stmt_assert
  */
 typedef struct PLpgSQL_stmt_execsql
 {
-	int			cmd_type;
+	PLpgSQL_stmt_type cmd_type;
 	int			lineno;
 	PLpgSQL_expr *sqlstmt;
 	bool		mod_stmt;		/* is the stmt INSERT/UPDATE/DELETE?  Note:
@@ -760,7 +760,7 @@ typedef struct PLpgSQL_stmt_execsql
  */
 typedef struct PLpgSQL_stmt_dynexecute
 {
-	int			cmd_type;
+	PLpgSQL_stmt_type cmd_type;
 	int			lineno;
 	PLpgSQL_expr *query;		/* string expression */
 	bool		into;			/* INTO supplied? */
@@ -1111,10 +1111,10 @@ extern void plpgsql_exec_get_datum_type_info(PLpgSQL_execstate *estate,
  */
 extern void plpgsql_ns_init(void);
 extern void plpgsql_ns_push(const char *label,
-				enum PLpgSQL_label_types label_type);
+				PLpgSQL_label_type label_type);
 extern void plpgsql_ns_pop(void);
 extern PLpgSQL_nsitem *plpgsql_ns_top(void);
-extern void plpgsql_ns_additem(int itemtype, int itemno, const char *name);
+extern void plpgsql_ns_additem(PLpgSQL_nsitem_type itemtype, int itemno, const char *name);
 extern PLpgSQL_nsitem *plpgsql_ns_lookup(PLpgSQL_nsitem *ns_cur, bool localmode,
 				  const char *name1, const char *name2,
 				  const char *name3, int *names_used);
@@ -1126,7 +1126,7 @@ extern PLpgSQL_nsitem *plpgsql_ns_find_nearest_loop(PLpgSQL_nsitem *ns_cur);
  * Other functions in pl_funcs.c
  */
 extern const char *plpgsql_stmt_typename(PLpgSQL_stmt *stmt);
-extern const char *plpgsql_getdiag_kindname(int kind);
+extern const char *plpgsql_getdiag_kindname(PLpgSQL_getdiag_kind kind);
 extern void plpgsql_free_function_memory(PLpgSQL_function *func);
 extern void plpgsql_dumptree(PLpgSQL_function *func);