plpgsql-still-less-reserved-1.patch

diff --git a/src/pl/plpgsql/src/pl_comp.c b/src/pl/plpgsql/src/pl_comp.c
index 8bacc74..03e7c6c 100644
*** a/src/pl/plpgsql/src/pl_comp.c
--- b/src/pl/plpgsql/src/pl_comp.c
*************** make_datum_param(PLpgSQL_expr *expr, int
*** 1353,1358 ****
--- 1353,1361 ----
   * yytxt is the original token text; we need this to check for quoting,
   * so that later checks for unreserved keywords work properly.
   *
+  * We attempt to recognize the token as a variable only if lookup is true
+  * and the plpgsql_IdentifierLookup context permits it.
+  *
   * If recognized as a variable, fill in *wdatum and return true;
   * if not recognized, fill in *word and return false.
   * (Note: those two pointers actually point to members of the same union,
*************** make_datum_param(PLpgSQL_expr *expr, int
*** 1360,1376 ****
   * ----------
   */
  bool
! plpgsql_parse_word(char *word1, const char *yytxt,
  				   PLwdatum *wdatum, PLword *word)
  {
  	PLpgSQL_nsitem *ns;
  
  	/*
! 	 * We should do nothing in DECLARE sections.  In SQL expressions, there's
! 	 * no need to do anything either --- lookup will happen when the
! 	 * expression is compiled.
  	 */
! 	if (plpgsql_IdentifierLookup == IDENTIFIER_LOOKUP_NORMAL)
  	{
  		/*
  		 * Do a lookup in the current namespace stack
--- 1363,1379 ----
   * ----------
   */
  bool
! plpgsql_parse_word(char *word1, const char *yytxt, bool lookup,
  				   PLwdatum *wdatum, PLword *word)
  {
  	PLpgSQL_nsitem *ns;
  
  	/*
! 	 * We should not lookup variables in DECLARE sections.  In SQL
! 	 * expressions, there's no need to do so either --- lookup will happen
! 	 * when the expression is compiled.
  	 */
! 	if (lookup && plpgsql_IdentifierLookup == IDENTIFIER_LOOKUP_NORMAL)
  	{
  		/*
  		 * Do a lookup in the current namespace stack
diff --git a/src/pl/plpgsql/src/pl_scanner.c b/src/pl/plpgsql/src/pl_scanner.c
index ab18946..3e746d1 100644
*** a/src/pl/plpgsql/src/pl_scanner.c
--- b/src/pl/plpgsql/src/pl_scanner.c
*************** plpgsql_yylex(void)
*** 328,333 ****
--- 328,334 ----
  				push_back_token(tok2, &aux2);
  				if (plpgsql_parse_word(aux1.lval.str,
  									   core_yy.scanbuf + aux1.lloc,
+ 									   true,
  									   &aux1.lval.wdatum,
  									   &aux1.lval.word))
  					tok1 = T_DATUM;
*************** plpgsql_yylex(void)
*** 349,401 ****
  			push_back_token(tok2, &aux2);
  
  			/*
! 			 * If we are at start of statement, prefer unreserved keywords
! 			 * over variable names, unless the next token is assignment or
! 			 * '[', in which case prefer variable names.  (Note we need not
! 			 * consider '.' as the next token; that case was handled above,
! 			 * and we always prefer variable names in that case.)  If we are
! 			 * not at start of statement, always prefer variable names over
! 			 * unreserved keywords.
  			 */
! 			if (AT_STMT_START(plpgsql_yytoken) &&
! 				!(tok2 == '=' || tok2 == COLON_EQUALS || tok2 == '['))
  			{
! 				/* try for unreserved keyword, then for variable name */
! 				if (core_yy.scanbuf[aux1.lloc] != '"' &&
! 					(kw = ScanKeywordLookup(aux1.lval.str,
! 											unreserved_keywords,
! 											num_unreserved_keywords)))
! 				{
! 					aux1.lval.keyword = kw->name;
! 					tok1 = kw->value;
! 				}
! 				else if (plpgsql_parse_word(aux1.lval.str,
! 											core_yy.scanbuf + aux1.lloc,
! 											&aux1.lval.wdatum,
! 											&aux1.lval.word))
! 					tok1 = T_DATUM;
! 				else
! 					tok1 = T_WORD;
  			}
  			else
! 			{
! 				/* try for variable name, then for unreserved keyword */
! 				if (plpgsql_parse_word(aux1.lval.str,
! 									   core_yy.scanbuf + aux1.lloc,
! 									   &aux1.lval.wdatum,
! 									   &aux1.lval.word))
! 					tok1 = T_DATUM;
! 				else if (!aux1.lval.word.quoted &&
! 						 (kw = ScanKeywordLookup(aux1.lval.word.ident,
! 												 unreserved_keywords,
! 												 num_unreserved_keywords)))
! 				{
! 					aux1.lval.keyword = kw->name;
! 					tok1 = kw->value;
! 				}
! 				else
! 					tok1 = T_WORD;
! 			}
  		}
  	}
  	else
--- 350,389 ----
  			push_back_token(tok2, &aux2);
  
  			/*
! 			 * See if it matches a variable name, except in the context where
! 			 * we are at start of statement and the next token isn't
! 			 * assignment or '['.  In that case, it couldn't validly be a
! 			 * variable name, and skipping the lookup allows variable names to
! 			 * be used that would conflict with plpgsql or core keywords that
! 			 * introduce statements (e.g., "comment").  Without this special
! 			 * logic, every statement-introducing keyword would effectively be
! 			 * reserved in PL/pgSQL, which would be unpleasant.
! 			 *
! 			 * If it isn't a variable name, try to match against unreserved
! 			 * plpgsql keywords.  If not one of those either, it's T_WORD.
! 			 *
! 			 * Note: we must call plpgsql_parse_word even if we don't want to
! 			 * do variable lookup, because it sets up aux1.lval.word for the
! 			 * non-variable cases.
  			 */
! 			if (plpgsql_parse_word(aux1.lval.str,
! 								   core_yy.scanbuf + aux1.lloc,
! 								   (!AT_STMT_START(plpgsql_yytoken) ||
! 									(tok2 == '=' || tok2 == COLON_EQUALS ||
! 									 tok2 == '[')),
! 								   &aux1.lval.wdatum,
! 								   &aux1.lval.word))
! 				tok1 = T_DATUM;
! 			else if (!aux1.lval.word.quoted &&
! 					 (kw = ScanKeywordLookup(aux1.lval.word.ident,
! 											 unreserved_keywords,
! 											 num_unreserved_keywords)))
  			{
! 				aux1.lval.keyword = kw->name;
! 				tok1 = kw->value;
  			}
  			else
! 				tok1 = T_WORD;
  		}
  	}
  	else
diff --git a/src/pl/plpgsql/src/plpgsql.h b/src/pl/plpgsql/src/plpgsql.h
index 42177cc..962b9c2 100644
*** a/src/pl/plpgsql/src/plpgsql.h
--- b/src/pl/plpgsql/src/plpgsql.h
*************** extern PLpgSQL_function *plpgsql_compile
*** 1175,1181 ****
  extern PLpgSQL_function *plpgsql_compile_inline(char *proc_source);
  extern void plpgsql_parser_setup(struct ParseState *pstate,
  					 PLpgSQL_expr *expr);
! extern bool plpgsql_parse_word(char *word1, const char *yytxt,
  				   PLwdatum *wdatum, PLword *word);
  extern bool plpgsql_parse_dblword(char *word1, char *word2,
  					  PLwdatum *wdatum, PLcword *cword);
--- 1175,1181 ----
  extern PLpgSQL_function *plpgsql_compile_inline(char *proc_source);
  extern void plpgsql_parser_setup(struct ParseState *pstate,
  					 PLpgSQL_expr *expr);
! extern bool plpgsql_parse_word(char *word1, const char *yytxt, bool lookup,
  				   PLwdatum *wdatum, PLword *word);
  extern bool plpgsql_parse_dblword(char *word1, char *word2,
  					  PLwdatum *wdatum, PLcword *cword);
diff --git a/src/test/regress/expected/plpgsql.out b/src/test/regress/expected/plpgsql.out
index b9a987d..d2f68e1 100644
*** a/src/test/regress/expected/plpgsql.out
--- b/src/test/regress/expected/plpgsql.out
*************** select unreserved_test();
*** 4781,4786 ****
--- 4781,4807 ----
                43
  (1 row)
  
+ create or replace function unreserved_test() returns int as $$
+ declare
+   comment int := 21;
+ begin
+   comment := comment * 2;
+   comment on function unreserved_test() is 'this is a test';
+   return comment;
+ end
+ $$ language plpgsql;
+ select unreserved_test();
+  unreserved_test 
+ -----------------
+               42
+ (1 row)
+ 
+ select obj_description('unreserved_test()'::regprocedure, 'pg_proc');
+  obj_description 
+ -----------------
+  this is a test
+ (1 row)
+ 
  drop function unreserved_test();
  --
  -- Test FOREACH over arrays
diff --git a/src/test/regress/sql/plpgsql.sql b/src/test/regress/sql/plpgsql.sql
index 01239e2..9c8cf75 100644
*** a/src/test/regress/sql/plpgsql.sql
--- b/src/test/regress/sql/plpgsql.sql
*************** $$ language plpgsql;
*** 3892,3897 ****
--- 3892,3911 ----
  
  select unreserved_test();
  
+ create or replace function unreserved_test() returns int as $$
+ declare
+   comment int := 21;
+ begin
+   comment := comment * 2;
+   comment on function unreserved_test() is 'this is a test';
+   return comment;
+ end
+ $$ language plpgsql;
+ 
+ select unreserved_test();
+ 
+ select obj_description('unreserved_test()'::regprocedure, 'pg_proc');
+ 
  drop function unreserved_test();
  
  --