Make nullSemAction const, add 'const' decorators to related functions

hlinnaka · hlinnaka · commit 85829c973cb3 · 2024-08-06T23:04:22.000+03:00
To make it more clear that these should never be modified. Reviewed-by: Andres Freund Discussion: https://www.postgresql.org/message-id/54c29fb0-edf2-48ea-9814-44e918bbd6e8@iki.fi
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
@@ -514,7 +514,7 @@ static JsonParseErrorType transform_string_values_scalar(void *state, char *toke
  * returned when escontext is an ErrorSaveContext).
  */
 bool
-pg_parse_json_or_errsave(JsonLexContext *lex, JsonSemAction *sem,
+pg_parse_json_or_errsave(JsonLexContext *lex, const JsonSemAction *sem,
 						 Node *escontext)
 {
 	JsonParseErrorType result;
diff --git a/src/common/jsonapi.c b/src/common/jsonapi.c
@@ -213,15 +213,15 @@ static char JSON_PROD_GOAL[] = {JSON_TOKEN_END, JSON_NT_JSON, 0};
 static inline JsonParseErrorType json_lex_string(JsonLexContext *lex);
 static inline JsonParseErrorType json_lex_number(JsonLexContext *lex, const char *s,
 												 bool *num_err, size_t *total_len);
-static inline JsonParseErrorType parse_scalar(JsonLexContext *lex, JsonSemAction *sem);
-static JsonParseErrorType parse_object_field(JsonLexContext *lex, JsonSemAction *sem);
-static JsonParseErrorType parse_object(JsonLexContext *lex, JsonSemAction *sem);
-static JsonParseErrorType parse_array_element(JsonLexContext *lex, JsonSemAction *sem);
-static JsonParseErrorType parse_array(JsonLexContext *lex, JsonSemAction *sem);
+static inline JsonParseErrorType parse_scalar(JsonLexContext *lex, const JsonSemAction *sem);
+static JsonParseErrorType parse_object_field(JsonLexContext *lex, const JsonSemAction *sem);
+static JsonParseErrorType parse_object(JsonLexContext *lex, const JsonSemAction *sem);
+static JsonParseErrorType parse_array_element(JsonLexContext *lex, const JsonSemAction *sem);
+static JsonParseErrorType parse_array(JsonLexContext *lex, const JsonSemAction *sem);
 static JsonParseErrorType report_parse_error(JsonParseContext ctx, JsonLexContext *lex);
 
 /* the null action object used for pure validation */
-JsonSemAction nullSemAction =
+const JsonSemAction nullSemAction =
 {
 	NULL, NULL, NULL, NULL, NULL,
 	NULL, NULL, NULL, NULL, NULL
@@ -519,7 +519,7 @@ freeJsonLexContext(JsonLexContext *lex)
  * other differences.
  */
 JsonParseErrorType
-pg_parse_json(JsonLexContext *lex, JsonSemAction *sem)
+pg_parse_json(JsonLexContext *lex, const JsonSemAction *sem)
 {
 #ifdef FORCE_JSON_PSTACK
 
@@ -648,7 +648,7 @@ json_count_array_elements(JsonLexContext *lex, int *elements)
  */
 JsonParseErrorType
 pg_parse_json_incremental(JsonLexContext *lex,
-						  JsonSemAction *sem,
+						  const JsonSemAction *sem,
 						  const char *json,
 						  size_t len,
 						  bool is_last)
@@ -1005,7 +1005,7 @@ pg_parse_json_incremental(JsonLexContext *lex,
  *	  - object field
  */
 static inline JsonParseErrorType
-parse_scalar(JsonLexContext *lex, JsonSemAction *sem)
+parse_scalar(JsonLexContext *lex, const JsonSemAction *sem)
 {
 	char	   *val = NULL;
 	json_scalar_action sfunc = sem->scalar;
@@ -1049,7 +1049,7 @@ parse_scalar(JsonLexContext *lex, JsonSemAction *sem)
 }
 
 static JsonParseErrorType
-parse_object_field(JsonLexContext *lex, JsonSemAction *sem)
+parse_object_field(JsonLexContext *lex, const JsonSemAction *sem)
 {
 	/*
 	 * An object field is "fieldname" : value where value can be a scalar,
@@ -1111,7 +1111,7 @@ parse_object_field(JsonLexContext *lex, JsonSemAction *sem)
 }
 
 static JsonParseErrorType
-parse_object(JsonLexContext *lex, JsonSemAction *sem)
+parse_object(JsonLexContext *lex, const JsonSemAction *sem)
 {
 	/*
 	 * an object is a possibly empty sequence of object fields, separated by
@@ -1185,7 +1185,7 @@ parse_object(JsonLexContext *lex, JsonSemAction *sem)
 }
 
 static JsonParseErrorType
-parse_array_element(JsonLexContext *lex, JsonSemAction *sem)
+parse_array_element(JsonLexContext *lex, const JsonSemAction *sem)
 {
 	json_aelem_action astart = sem->array_element_start;
 	json_aelem_action aend = sem->array_element_end;
@@ -1229,7 +1229,7 @@ parse_array_element(JsonLexContext *lex, JsonSemAction *sem)
 }
 
 static JsonParseErrorType
-parse_array(JsonLexContext *lex, JsonSemAction *sem)
+parse_array(JsonLexContext *lex, const JsonSemAction *sem)
 {
 	/*
 	 * an array is a possibly empty sequence of array elements, separated by
diff --git a/src/include/common/jsonapi.h b/src/include/common/jsonapi.h
@@ -153,16 +153,16 @@ typedef struct JsonSemAction
  * does nothing and just continues.
  */
 extern JsonParseErrorType pg_parse_json(JsonLexContext *lex,
-										JsonSemAction *sem);
+										const JsonSemAction *sem);
 
 extern JsonParseErrorType pg_parse_json_incremental(JsonLexContext *lex,
-													JsonSemAction *sem,
+													const JsonSemAction *sem,
 													const char *json,
 													size_t len,
 													bool is_last);
 
 /* the null action object used for pure validation */
-extern PGDLLIMPORT JsonSemAction nullSemAction;
+extern PGDLLIMPORT const JsonSemAction nullSemAction;
 
 /*
  * json_count_array_elements performs a fast secondary parse to determine the
diff --git a/src/include/utils/jsonfuncs.h b/src/include/utils/jsonfuncs.h
@@ -41,7 +41,7 @@ typedef text *(*JsonTransformStringValuesAction) (void *state, char *elem_value,
 extern JsonLexContext *makeJsonLexContext(JsonLexContext *lex, text *json, bool need_escapes);
 
 /* try to parse json, and errsave(escontext) on failure */
-extern bool pg_parse_json_or_errsave(JsonLexContext *lex, JsonSemAction *sem,
+extern bool pg_parse_json_or_errsave(JsonLexContext *lex, const JsonSemAction *sem,
 									 struct Node *escontext);
 
 #define pg_parse_json_or_ereport(lex, sem) \
diff --git a/src/test/modules/test_json_parser/test_json_parser_incremental.c b/src/test/modules/test_json_parser/test_json_parser_incremental.c
@@ -84,7 +84,7 @@ main(int argc, char **argv)
 	size_t		chunk_size = DEFAULT_CHUNK_SIZE;
 	struct stat statbuf;
 	off_t		bytes_left;
-	JsonSemAction *testsem = &nullSemAction;
+	const JsonSemAction *testsem = &nullSemAction;
 	char	   *testfile;
 	int			c;
 	bool		need_strings = false;

Original file line number	Diff line number	Diff line change
`@@ -514,7 +514,7 @@ static JsonParseErrorType transform_string_values_scalar(void state, char toke`
`514`	`514`	`* returned when escontext is an ErrorSaveContext).`
`515`	`515`	`*/`
`516`	`516`	`bool`
`517`		`-pg_parse_json_or_errsave(JsonLexContext lex, JsonSemAction sem,`
	`517`	`+pg_parse_json_or_errsave(JsonLexContext lex, const JsonSemAction sem,`
`518`	`518`	`Node *escontext)`
`519`	`519`	`{`
`520`	`520`	`JsonParseErrorType result;`