From: Tom Lane Date: Thu, 5 Nov 2009 16:58:36 +0000 (+0000) Subject: Remove plpgsql's RENAME declaration, which has bizarre and mostly nonfunctional X-Git-Tag: REL8_5_ALPHA3~155 X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=c29ae527e90d7704ec85f69a3fe67996e654a6bd;p=postgresql Remove plpgsql's RENAME declaration, which has bizarre and mostly nonfunctional behavior, and is so little used that no one has been interested in fixing it. To ensure that possible uses are covered, remove the ALIAS declaration's arbitrary restriction that only $n identifiers can be aliased. (We could alternatively make RENAME act just like ALIAS, but per discussion having two different ways to do the same thing is probably more confusing than helpful.) --- diff --git a/doc/src/sgml/plpgsql.sgml b/doc/src/sgml/plpgsql.sgml index 65d508c37e..401d1216e4 100644 --- a/doc/src/sgml/plpgsql.sgml +++ b/doc/src/sgml/plpgsql.sgml @@ -1,4 +1,4 @@ - + <application>PL/pgSQL</application> - <acronym>SQL</acronym> Procedural Language @@ -135,7 +135,7 @@ and anyenum. The actual data types handled by a polymorphic function can vary from call to call, as discussed in . - An example is shown in . + An example is shown in . @@ -163,7 +163,7 @@ Specific examples appear in - and + and . @@ -353,8 +353,8 @@ user_id CONSTANT integer := 10; - - Aliases for Function Parameters + + Declaring Function Parameters Parameters passed to functions are named with the identifiers @@ -401,7 +401,7 @@ $$ LANGUAGE plpgsql; These two examples are not perfectly equivalent. In the first case, subtotal could be referenced as sales_tax.subtotal, but in the second case it could not. - (Had we attached a label to the block, subtotal could + (Had we attached a label to the inner block, subtotal could be qualified with that label, instead.) @@ -532,6 +532,38 @@ $$ LANGUAGE plpgsql; + + <literal>ALIAS</> + + +newname ALIAS FOR oldname; + + + + The ALIAS syntax is more general than is suggested in the + previous section: you can declare an alias for any variable, not just + function parameters. The main practical use for this is to assign + a different name for variables with predetermined names, such as + NEW or OLD within + a trigger procedure. + + + + Examples: + +DECLARE + prior ALIAS FOR old; + updated ALIAS FOR new; + + + + + Since ALIAS creates two different ways to name the same + object, unrestricted use can be confusing. It's best to use it only + for the purpose of overriding predetermined names. + + + Copying Types @@ -664,39 +696,6 @@ SELECT merge_fields(t.*) FROM table1 t WHERE ... ; structure on-the-fly. - - - <literal>RENAME</> - - -RENAME oldname TO newname; - - - - Using the RENAME declaration you can change the - name of a variable, record or row. This is primarily useful if - NEW or OLD should be - referenced by another name inside a trigger procedure. See also - ALIAS. - - - - Examples: - -RENAME id TO user_id; -RENAME this_var TO that_var; - - - - - - RENAME appears to be broken as of - PostgreSQL 7.3. Fixing this is of low priority, - since ALIAS covers most of the practical uses - of RENAME. - - - diff --git a/src/pl/plpgsql/src/gram.y b/src/pl/plpgsql/src/gram.y index ec6b285bf2..e2e3f203ae 100644 --- a/src/pl/plpgsql/src/gram.y +++ b/src/pl/plpgsql/src/gram.y @@ -9,7 +9,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/pl/plpgsql/src/gram.y,v 1.129 2009/11/04 22:26:07 tgl Exp $ + * $PostgreSQL: pgsql/src/pl/plpgsql/src/gram.y,v 1.130 2009/11/05 16:58:36 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -128,7 +128,6 @@ static List *read_raise_options(void); %type decl_sect %type decl_varname -%type decl_renname %type decl_const decl_notnull exit_type %type decl_defval decl_cursor_query %type decl_datatype @@ -218,7 +217,6 @@ static List *read_raise_options(void); %token K_PERFORM %token K_ROW_COUNT %token K_RAISE -%token K_RENAME %token K_RESULT_OID %token K_RETURN %token K_REVERSE @@ -382,10 +380,6 @@ decl_statement : decl_varname decl_const decl_datatype decl_notnull decl_defval plpgsql_ns_additem($4->itemtype, $4->itemno, $1.name); } - | K_RENAME decl_renname K_TO decl_renname ';' - { - plpgsql_ns_rename($2, $4); - } | decl_varname opt_scrollable K_CURSOR { plpgsql_ns_push($1.name); } decl_cursor_args decl_is_for decl_cursor_query @@ -521,9 +515,8 @@ decl_aliasitem : any_identifier char *name; PLpgSQL_nsitem *nsi; + /* XXX should allow block-label-qualified names */ plpgsql_convert_ident($1, &name, 1); - if (name[0] != '$') - yyerror("only positional parameters can be aliased"); plpgsql_ns_setlocal(false); @@ -532,8 +525,8 @@ decl_aliasitem : any_identifier { plpgsql_error_lineno = plpgsql_scanner_lineno(); ereport(ERROR, - (errcode(ERRCODE_UNDEFINED_PARAMETER), - errmsg("function has no parameter \"%s\"", + (errcode(ERRCODE_UNDEFINED_OBJECT), + errmsg("variable \"%s\" does not exist", name))); } @@ -573,17 +566,6 @@ decl_varname : T_WORD } ; -/* XXX this is broken because it doesn't allow for T_SCALAR,T_ROW,T_RECORD */ -decl_renname : T_WORD - { - char *name; - - plpgsql_convert_ident(yytext, &name, 1); - /* the result must be palloc'd, see plpgsql_ns_rename */ - $$ = name; - } - ; - decl_const : { $$ = false; } | K_CONSTANT diff --git a/src/pl/plpgsql/src/pl_funcs.c b/src/pl/plpgsql/src/pl_funcs.c index 274d027114..790e2e86ba 100644 --- a/src/pl/plpgsql/src/pl_funcs.c +++ b/src/pl/plpgsql/src/pl_funcs.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_funcs.c,v 1.82 2009/11/04 22:26:07 tgl Exp $ + * $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_funcs.c,v 1.83 2009/11/05 16:58:36 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -235,48 +235,6 @@ plpgsql_ns_lookup_label(const char *name) } -/* ---------- - * plpgsql_ns_rename Rename a namespace entry - * ---------- - */ -void -plpgsql_ns_rename(char *oldname, char *newname) -{ - PLpgSQL_ns *ns; - PLpgSQL_nsitem *newitem; - int i; - - /* - * Lookup name in the namestack - */ - for (ns = ns_current; ns != NULL; ns = ns->upper) - { - for (i = 1; i < ns->items_used; i++) - { - if (strcmp(ns->items[i]->name, oldname) == 0) - { - newitem = palloc(sizeof(PLpgSQL_nsitem) + strlen(newname)); - newitem->itemtype = ns->items[i]->itemtype; - newitem->itemno = ns->items[i]->itemno; - strcpy(newitem->name, newname); - - pfree(oldname); - pfree(newname); - - pfree(ns->items[i]); - ns->items[i] = newitem; - return; - } - } - } - - ereport(ERROR, - (errcode(ERRCODE_UNDEFINED_OBJECT), - errmsg("variable \"%s\" does not exist in the current block", - oldname))); -} - - /* ---------- * plpgsql_convert_ident * diff --git a/src/pl/plpgsql/src/plpgsql.h b/src/pl/plpgsql/src/plpgsql.h index 3d0f155a88..193d8d5c4c 100644 --- a/src/pl/plpgsql/src/plpgsql.h +++ b/src/pl/plpgsql/src/plpgsql.h @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/pl/plpgsql/src/plpgsql.h,v 1.118 2009/11/04 22:26:07 tgl Exp $ + * $PostgreSQL: pgsql/src/pl/plpgsql/src/plpgsql.h,v 1.119 2009/11/05 16:58:36 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -287,7 +287,7 @@ typedef struct { /* Item in the compilers namestack */ int itemtype; int itemno; - char name[1]; + char name[1]; /* actually, as long as needed */ } PLpgSQL_nsitem; @@ -851,7 +851,6 @@ extern void plpgsql_ns_additem(int itemtype, int itemno, const char *name); extern PLpgSQL_nsitem *plpgsql_ns_lookup(const char *name1, const char *name2, const char *name3, int *names_used); extern PLpgSQL_nsitem *plpgsql_ns_lookup_label(const char *name); -extern void plpgsql_ns_rename(char *oldname, char *newname); /* ---------- * Other functions in pl_funcs.c diff --git a/src/pl/plpgsql/src/scan.l b/src/pl/plpgsql/src/scan.l index b309d81187..3563b2ff15 100644 --- a/src/pl/plpgsql/src/scan.l +++ b/src/pl/plpgsql/src/scan.l @@ -9,7 +9,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/pl/plpgsql/src/scan.l,v 1.72 2009/09/29 20:05:29 tgl Exp $ + * $PostgreSQL: pgsql/src/pl/plpgsql/src/scan.l,v 1.73 2009/11/05 16:58:36 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -183,7 +183,6 @@ open { return K_OPEN; } or { return K_OR; } perform { return K_PERFORM; } raise { return K_RAISE; } -rename { return K_RENAME; } result_oid { return K_RESULT_OID; } return { return K_RETURN; } reverse { return K_REVERSE; } diff --git a/src/test/regress/expected/plpgsql.out b/src/test/regress/expected/plpgsql.out index e3cacf589e..2e97bec42e 100644 --- a/src/test/regress/expected/plpgsql.out +++ b/src/test/regress/expected/plpgsql.out @@ -162,7 +162,7 @@ create trigger tg_pfield_ad after delete create function tg_pslot_biu() returns trigger as $proc$ declare pfrec record; - rename new to ps; + ps alias for new; begin select into pfrec * from PField where name = ps.pfname; if not found then diff --git a/src/test/regress/sql/plpgsql.sql b/src/test/regress/sql/plpgsql.sql index 3e6b6de539..83cda97d1b 100644 --- a/src/test/regress/sql/plpgsql.sql +++ b/src/test/regress/sql/plpgsql.sql @@ -211,7 +211,7 @@ create trigger tg_pfield_ad after delete create function tg_pslot_biu() returns trigger as $proc$ declare pfrec record; - rename new to ps; + ps alias for new; begin select into pfrec * from PField where name = ps.pfname; if not found then