From a54d3fb2e6ce3db9d0c3ad911ae6165e527b21f5 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Tue, 27 Nov 2007 19:58:44 +0000 Subject: [PATCH] Fix plpgsql to not lookup block labels except in contexts where a block label is sane (eg, EXIT argument or first part of a qualified identifier), and cause more-closely-nested record variables to take precedence over outer block labels. This cures the breakage exhibited by Marko Kreen that 8.3 no longer allowed a function's name to be used for a variable within the function, and makes plpgsql's handling of block labels more like Oracle's. It's important to fix this now because we are documenting the use of block labels as variable qualifiers for the first time in 8.3. --- src/pl/plpgsql/src/gram.y | 42 ++++++-- src/pl/plpgsql/src/pl_comp.c | 193 ++++++++++++---------------------- src/pl/plpgsql/src/pl_funcs.c | 120 ++++++++++++++------- src/pl/plpgsql/src/plpgsql.h | 16 +-- 4 files changed, 191 insertions(+), 180 deletions(-) diff --git a/src/pl/plpgsql/src/gram.y b/src/pl/plpgsql/src/gram.y index ffb16bea1c..4541c9839d 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 1.106 2007/11/09 23:58:32 tgl Exp $ + * $PostgreSQL: pgsql/src/pl/plpgsql/src/gram.y,v 1.107 2007/11/27 19:58:44 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -43,6 +43,7 @@ static PLpgSQL_row *make_scalar_list1(const char *initial_name, int lineno); static void check_sql_expr(const char *stmt); static void plpgsql_sql_error_callback(void *arg); +static char *check_label(const char *yytxt); static void check_labels(const char *start_label, const char *end_label); @@ -214,7 +215,6 @@ static void check_labels(const char *start_label, %token T_ROW %token T_RECORD %token T_DTYPE -%token T_LABEL %token T_WORD %token T_ERROR @@ -505,7 +505,8 @@ decl_aliasitem : T_WORD yyerror("only positional parameters can be aliased"); plpgsql_ns_setlocal(false); - nsi = plpgsql_ns_lookup(name, NULL); + + nsi = plpgsql_ns_lookup(name, NULL, NULL, NULL); if (nsi == NULL) { plpgsql_error_lineno = plpgsql_scanner_lineno(); @@ -1642,20 +1643,28 @@ opt_block_label : } ; +/* + * need all the options because scanner will have tried to resolve as variable + */ opt_label : { $$ = NULL; } - | T_LABEL - { - char *label_name; - plpgsql_convert_ident(yytext, &label_name, 1); - $$ = label_name; - } | T_WORD { - /* just to give a better error than "syntax error" */ - yyerror("no such label"); + $$ = check_label(yytext); + } + | T_SCALAR + { + $$ = check_label(yytext); + } + | T_RECORD + { + $$ = check_label(yytext); + } + | T_ROW + { + $$ = check_label(yytext); } ; @@ -2484,6 +2493,17 @@ plpgsql_sql_error_callback(void *arg) errposition(0); } +static char * +check_label(const char *yytxt) +{ + char *label_name; + + plpgsql_convert_ident(yytxt, &label_name, 1); + if (plpgsql_ns_lookup_label(label_name) == NULL) + yyerror("no such label"); + return label_name; +} + static void check_labels(const char *start_label, const char *end_label) { diff --git a/src/pl/plpgsql/src/pl_comp.c b/src/pl/plpgsql/src/pl_comp.c index edb423e521..2e76b5e187 100644 --- a/src/pl/plpgsql/src/pl_comp.c +++ b/src/pl/plpgsql/src/pl_comp.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_comp.c,v 1.119 2007/11/15 21:14:46 momjian Exp $ + * $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_comp.c,v 1.120 2007/11/27 19:58:44 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -787,7 +787,7 @@ plpgsql_compile_error_callback(void *arg) * ---------- */ int -plpgsql_parse_word(char *word) +plpgsql_parse_word(const char *word) { PLpgSQL_nsitem *nse; char *cp[1]; @@ -797,6 +797,7 @@ plpgsql_parse_word(char *word) /* * Recognize tg_argv when compiling triggers + * (XXX this sucks, it should be a regular variable in the namestack) */ if (plpgsql_curr_compile->fn_functype == T_TRIGGER) { @@ -825,15 +826,13 @@ plpgsql_parse_word(char *word) /* * Do a lookup on the compiler's namestack */ - nse = plpgsql_ns_lookup(cp[0], NULL); + nse = plpgsql_ns_lookup(cp[0], NULL, NULL, NULL); + pfree(cp[0]); + if (nse != NULL) { - pfree(cp[0]); switch (nse->itemtype) { - case PLPGSQL_NSTYPE_LABEL: - return T_LABEL; - case PLPGSQL_NSTYPE_VAR: plpgsql_yylval.scalar = plpgsql_Datums[nse->itemno]; return T_SCALAR; @@ -855,7 +854,6 @@ plpgsql_parse_word(char *word) * Nothing found - up to now it's a word without any special meaning for * us. */ - pfree(cp[0]); return T_WORD; } @@ -866,18 +864,19 @@ plpgsql_parse_word(char *word) * ---------- */ int -plpgsql_parse_dblword(char *word) +plpgsql_parse_dblword(const char *word) { PLpgSQL_nsitem *ns; char *cp[2]; + int nnames; /* Do case conversion and word separation */ plpgsql_convert_ident(word, cp, 2); /* - * Lookup the first word + * Do a lookup on the compiler's namestack */ - ns = plpgsql_ns_lookup(cp[0], NULL); + ns = plpgsql_ns_lookup(cp[0], cp[1], NULL, &nnames); if (ns == NULL) { pfree(cp[0]); @@ -887,39 +886,15 @@ plpgsql_parse_dblword(char *word) switch (ns->itemtype) { - case PLPGSQL_NSTYPE_LABEL: - - /* - * First word is a label, so second word could be a variable, - * record or row in that bodies namestack. Anything else could - * only be something in a query given to the SPI manager and - * T_ERROR will get eaten up by the collector routines. - */ - ns = plpgsql_ns_lookup(cp[1], cp[0]); + case PLPGSQL_NSTYPE_VAR: + /* Block-qualified reference to scalar variable. */ + plpgsql_yylval.scalar = plpgsql_Datums[ns->itemno]; pfree(cp[0]); pfree(cp[1]); - if (ns == NULL) - return T_ERROR; - switch (ns->itemtype) - { - case PLPGSQL_NSTYPE_VAR: - plpgsql_yylval.scalar = plpgsql_Datums[ns->itemno]; - return T_SCALAR; - - case PLPGSQL_NSTYPE_REC: - plpgsql_yylval.rec = (PLpgSQL_rec *) (plpgsql_Datums[ns->itemno]); - return T_RECORD; - - case PLPGSQL_NSTYPE_ROW: - plpgsql_yylval.row = (PLpgSQL_row *) (plpgsql_Datums[ns->itemno]); - return T_ROW; - - default: - return T_ERROR; - } - break; + return T_SCALAR; case PLPGSQL_NSTYPE_REC: + if (nnames == 1) { /* * First word is a record name, so second word must be a field @@ -940,8 +915,17 @@ plpgsql_parse_dblword(char *word) pfree(cp[1]); return T_SCALAR; } + else + { + /* Block-qualified reference to record variable. */ + plpgsql_yylval.rec = (PLpgSQL_rec *) (plpgsql_Datums[ns->itemno]); + pfree(cp[0]); + pfree(cp[1]); + return T_RECORD; + } case PLPGSQL_NSTYPE_ROW: + if (nnames == 1) { /* * First word is a row name, so second word must be a field in @@ -967,6 +951,14 @@ plpgsql_parse_dblword(char *word) errmsg("row \"%s\" has no field \"%s\"", cp[0], cp[1]))); } + else + { + /* Block-qualified reference to row variable. */ + plpgsql_yylval.row = (PLpgSQL_row *) (plpgsql_Datums[ns->itemno]); + pfree(cp[0]); + pfree(cp[1]); + return T_ROW; + } default: break; @@ -984,38 +976,21 @@ plpgsql_parse_dblword(char *word) * ---------- */ int -plpgsql_parse_tripword(char *word) +plpgsql_parse_tripword(const char *word) { PLpgSQL_nsitem *ns; char *cp[3]; + int nnames; /* Do case conversion and word separation */ plpgsql_convert_ident(word, cp, 3); /* - * Lookup the first word - it must be a label + * Do a lookup on the compiler's namestack. + * Must find a qualified reference. */ - ns = plpgsql_ns_lookup(cp[0], NULL); - if (ns == NULL) - { - pfree(cp[0]); - pfree(cp[1]); - pfree(cp[2]); - return T_ERROR; - } - if (ns->itemtype != PLPGSQL_NSTYPE_LABEL) - { - pfree(cp[0]); - pfree(cp[1]); - pfree(cp[2]); - return T_ERROR; - } - - /* - * First word is a label, so second word could be a record or row - */ - ns = plpgsql_ns_lookup(cp[1], cp[0]); - if (ns == NULL) + ns = plpgsql_ns_lookup(cp[0], cp[1], cp[2], &nnames); + if (ns == NULL || nnames != 2) { pfree(cp[0]); pfree(cp[1]); @@ -1028,7 +1003,7 @@ plpgsql_parse_tripword(char *word) case PLPGSQL_NSTYPE_REC: { /* - * This word is a record name, so third word must be a field + * words 1/2 are a record name, so third word must be a field * in this record. */ PLpgSQL_recfield *new; @@ -1052,7 +1027,7 @@ plpgsql_parse_tripword(char *word) case PLPGSQL_NSTYPE_ROW: { /* - * This word is a row name, so third word must be a field in + * words 1/2 are a row name, so third word must be a field in * this row. */ PLpgSQL_row *row; @@ -1114,11 +1089,10 @@ plpgsql_parse_wordtype(char *word) pfree(cp[1]); /* - * Do a lookup on the compiler's namestack. But ensure it moves up to the - * toplevel. + * Do a lookup on the compiler's namestack. Ensure we scan all levels. */ old_nsstate = plpgsql_ns_setlocal(false); - nse = plpgsql_ns_lookup(cp[0], NULL); + nse = plpgsql_ns_lookup(cp[0], NULL, NULL, NULL); plpgsql_ns_setlocal(old_nsstate); if (nse != NULL) @@ -1200,32 +1174,21 @@ plpgsql_parse_dblwordtype(char *word) word[i] = '.'; plpgsql_convert_ident(word, cp, 3); word[i] = '%'; + pfree(cp[2]); /* - * Lookup the first word + * Do a lookup on the compiler's namestack. Ensure we scan all levels. + * We don't need to check number of names matched, because we will only + * consider scalar variables. */ - nse = plpgsql_ns_lookup(cp[0], NULL); + old_nsstate = plpgsql_ns_setlocal(false); + nse = plpgsql_ns_lookup(cp[0], cp[1], NULL, NULL); + plpgsql_ns_setlocal(old_nsstate); - /* - * If this is a label lookup the second word in that label's namestack - * level - */ - if (nse != NULL) + if (nse != NULL && nse->itemtype == PLPGSQL_NSTYPE_VAR) { - if (nse->itemtype == PLPGSQL_NSTYPE_LABEL) - { - old_nsstate = plpgsql_ns_setlocal(false); - nse = plpgsql_ns_lookup(cp[1], cp[0]); - plpgsql_ns_setlocal(old_nsstate); - - if (nse != NULL && nse->itemtype == PLPGSQL_NSTYPE_VAR) - { - plpgsql_yylval.dtype = ((PLpgSQL_var *) (plpgsql_Datums[nse->itemno]))->datatype; - result = T_DTYPE; - } - } - - /* Return T_ERROR if not found, otherwise T_DTYPE */ + plpgsql_yylval.dtype = ((PLpgSQL_var *) (plpgsql_Datums[nse->itemno]))->datatype; + result = T_DTYPE; goto done; } @@ -1291,8 +1254,6 @@ done: * plpgsql_parse_tripwordtype Same lookup for word.word.word%TYPE * ---------- */ -#define TYPE_JUNK_LEN 5 - int plpgsql_parse_tripwordtype(char *word) { @@ -1302,10 +1263,7 @@ plpgsql_parse_tripwordtype(char *word) HeapTuple typetup = NULL; Form_pg_class classStruct; Form_pg_attribute attrStruct; - char *cp[2]; - char *colname[1]; - int qualified_att_len; - int numdots = 0; + char *cp[4]; int i; RangeVar *relvar; MemoryContext oldCxt; @@ -1315,27 +1273,15 @@ plpgsql_parse_tripwordtype(char *word) oldCxt = MemoryContextSwitchTo(compile_tmp_cxt); /* Do case conversion and word separation */ - qualified_att_len = strlen(word) - TYPE_JUNK_LEN; - Assert(word[qualified_att_len] == '%'); + /* We convert %type to .type momentarily to keep converter happy */ + i = strlen(word) - 5; + Assert(word[i] == '%'); + word[i] = '.'; + plpgsql_convert_ident(word, cp, 4); + word[i] = '%'; + pfree(cp[3]); - for (i = 0; i < qualified_att_len; i++) - { - if (word[i] == '.' && ++numdots == 2) - break; - } - - cp[0] = (char *) palloc((i + 1) * sizeof(char)); - memcpy(cp[0], word, i * sizeof(char)); - cp[0][i] = '\0'; - - /* - * qualified_att_len - one based position + 1 (null terminator) - */ - cp[1] = (char *) palloc((qualified_att_len - i) * sizeof(char)); - memcpy(cp[1], &word[i + 1], (qualified_att_len - i - 1) * sizeof(char)); - cp[1][qualified_att_len - i - 1] = '\0'; - - relvar = makeRangeVarFromNameList(stringToQualifiedNameList(cp[0])); + relvar = makeRangeVar(cp[0], cp[1]); classOid = RangeVarGetRelid(relvar, true); if (!OidIsValid(classOid)) goto done; @@ -1359,8 +1305,7 @@ plpgsql_parse_tripwordtype(char *word) /* * Fetch the named table field and its type */ - plpgsql_convert_ident(cp[1], colname, 1); - attrtup = SearchSysCacheAttName(classOid, colname[0]); + attrtup = SearchSysCacheAttName(classOid, cp[2]); if (!HeapTupleIsValid(attrtup)) goto done; attrStruct = (Form_pg_attribute) GETSTRUCT(attrtup); @@ -1436,13 +1381,11 @@ plpgsql_parse_wordrowtype(char *word) * So word must be a namespace qualified table name. * ---------- */ -#define ROWTYPE_JUNK_LEN 8 - int plpgsql_parse_dblwordrowtype(char *word) { Oid classOid; - char *cp; + char *cp[3]; int i; RangeVar *relvar; MemoryContext oldCxt; @@ -1452,19 +1395,19 @@ plpgsql_parse_dblwordrowtype(char *word) /* Do case conversion and word separation */ /* We convert %rowtype to .rowtype momentarily to keep converter happy */ - i = strlen(word) - ROWTYPE_JUNK_LEN; + i = strlen(word) - 8; Assert(word[i] == '%'); - word[i] = '\0'; - cp = pstrdup(word); + word[i] = '.'; + plpgsql_convert_ident(word, cp, 3); word[i] = '%'; /* Lookup the relation */ - relvar = makeRangeVarFromNameList(stringToQualifiedNameList(cp)); + relvar = makeRangeVar(cp[0], cp[1]); classOid = RangeVarGetRelid(relvar, true); if (!OidIsValid(classOid)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_TABLE), - errmsg("relation \"%s\" does not exist", cp))); + errmsg("relation \"%s.%s\" does not exist", cp[0], cp[1]))); /* Build and return the row type struct */ plpgsql_yylval.dtype = plpgsql_build_datatype(get_rel_type_id(classOid), diff --git a/src/pl/plpgsql/src/pl_funcs.c b/src/pl/plpgsql/src/pl_funcs.c index 573bfd4e0c..66e0f47d8c 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 1.65 2007/11/15 22:25:17 momjian Exp $ + * $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_funcs.c,v 1.66 2007/11/27 19:58:44 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -126,9 +126,15 @@ plpgsql_ns_init(void) /* ---------- - * plpgsql_ns_setlocal Tell plpgsql_ns_lookup to or to - * not look into the current level - * only. + * plpgsql_ns_setlocal Tell plpgsql_ns_lookup whether to + * look into the current level only. + * + * This is a crock, but in the current design we need it because scan.l + * initiates name lookup, and the scanner does not know whether we are + * examining a name being declared in a DECLARE section. For that case + * we only want to know if there is a conflicting name earlier in the + * same DECLARE section. So the grammar must temporarily set local mode + * before scanning decl_varnames. * ---------- */ bool @@ -219,59 +225,98 @@ plpgsql_ns_additem(int itemtype, int itemno, const char *name) /* ---------- - * plpgsql_ns_lookup Lookup for a word in the namestack + * plpgsql_ns_lookup Lookup an identifier in the namestack + * + * Note that this only searches for variables, not labels. + * + * name1 must be non-NULL. Pass NULL for name2 and/or name3 if parsing a name + * with fewer than three components. + * + * If names_used isn't NULL, *names_used receives the number of names + * matched: 0 if no match, 1 if name1 matched an unqualified variable name, + * 2 if name1 and name2 matched a block label + variable name. + * + * Note that name3 is never directly matched to anything. However, if it + * isn't NULL, we will disregard qualified matches to scalar variables. + * Similarly, if name2 isn't NULL, we disregard unqualified matches to + * scalar variables. * ---------- */ PLpgSQL_nsitem * -plpgsql_ns_lookup(const char *name, const char *label) +plpgsql_ns_lookup(const char *name1, const char *name2, const char *name3, + int *names_used) { PLpgSQL_ns *ns; int i; - /* - * If a label is specified, lookup only in that - */ - if (label != NULL) + /* Scan each level of the namestack */ + for (ns = ns_current; ns != NULL; ns = ns->upper) { - for (ns = ns_current; ns != NULL; ns = ns->upper) + /* Check for unqualified match to variable name */ + for (i = 1; i < ns->items_used; i++) { - if (strcmp(ns->items[0]->name, label) == 0) + PLpgSQL_nsitem *nsitem = ns->items[i]; + + if (strcmp(nsitem->name, name1) == 0) { - for (i = 1; i < ns->items_used; i++) + if (name2 == NULL || + nsitem->itemtype != PLPGSQL_NSTYPE_VAR) { - if (strcmp(ns->items[i]->name, name) == 0) - return ns->items[i]; + if (names_used) + *names_used = 1; + return nsitem; } - return NULL; /* name not found in specified label */ } } - return NULL; /* label not found */ + + /* Check for qualified match to variable name */ + if (name2 != NULL && + strcmp(ns->items[0]->name, name1) == 0) + { + for (i = 1; i < ns->items_used; i++) + { + PLpgSQL_nsitem *nsitem = ns->items[i]; + + if (strcmp(nsitem->name, name2) == 0) + { + if (name3 == NULL || + nsitem->itemtype != PLPGSQL_NSTYPE_VAR) + { + if (names_used) + *names_used = 2; + return nsitem; + } + } + } + } + + if (ns_localmode) + break; /* do not look into upper levels */ } - /* - * No label given, lookup for visible labels ignoring localmode - */ + /* This is just to suppress possibly-uninitialized-variable warnings */ + if (names_used) + *names_used = 0; + return NULL; /* No match found */ +} + + +/* ---------- + * plpgsql_ns_lookup_label Lookup a label in the namestack + * ---------- + */ +PLpgSQL_nsitem * +plpgsql_ns_lookup_label(const char *name) +{ + PLpgSQL_ns *ns; + for (ns = ns_current; ns != NULL; ns = ns->upper) { if (strcmp(ns->items[0]->name, name) == 0) return ns->items[0]; } - /* - * Finally 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, name) == 0) - return ns->items[i]; - } - if (ns_localmode) - return NULL; /* name not found in current namespace */ - } - - return NULL; + return NULL; /* label not found */ } @@ -846,8 +891,9 @@ static void dump_exit(PLpgSQL_stmt_exit *stmt) { dump_ind(); - printf("%s label='%s'", - stmt->is_exit ? "EXIT" : "CONTINUE", stmt->label); + printf("%s", stmt->is_exit ? "EXIT" : "CONTINUE"); + if (stmt->label != NULL) + printf(" label='%s'", stmt->label); if (stmt->cond != NULL) { printf(" WHEN "); diff --git a/src/pl/plpgsql/src/plpgsql.h b/src/pl/plpgsql/src/plpgsql.h index 6ba0126b49..7bbed551ab 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 1.93 2007/11/15 22:25:17 momjian Exp $ + * $PostgreSQL: pgsql/src/pl/plpgsql/src/plpgsql.h,v 1.94 2007/11/27 19:58:44 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -473,7 +473,7 @@ typedef struct int cmd_type; int lineno; bool is_exit; /* Is this an exit or a continue? */ - char *label; + char *label; /* NULL if it's an unlabelled EXIT/CONTINUE */ PLpgSQL_expr *cond; } PLpgSQL_stmt_exit; @@ -723,9 +723,9 @@ extern PLpgSQL_plugin **plugin_ptr; */ extern PLpgSQL_function *plpgsql_compile(FunctionCallInfo fcinfo, bool forValidator); -extern int plpgsql_parse_word(char *word); -extern int plpgsql_parse_dblword(char *word); -extern int plpgsql_parse_tripword(char *word); +extern int plpgsql_parse_word(const char *word); +extern int plpgsql_parse_dblword(const char *word); +extern int plpgsql_parse_tripword(const char *word); extern int plpgsql_parse_wordtype(char *word); extern int plpgsql_parse_dblwordtype(char *word); extern int plpgsql_parse_tripwordtype(char *word); @@ -773,7 +773,7 @@ extern void plpgsql_dstring_append_char(PLpgSQL_dstring *ds, char c); extern char *plpgsql_dstring_get(PLpgSQL_dstring *ds); /* ---------- - * Functions for the namestack handling in pl_funcs.c + * Functions for namestack handling in pl_funcs.c * ---------- */ extern void plpgsql_ns_init(void); @@ -781,7 +781,9 @@ extern bool plpgsql_ns_setlocal(bool flag); extern void plpgsql_ns_push(const char *label); extern void plpgsql_ns_pop(void); extern void plpgsql_ns_additem(int itemtype, int itemno, const char *name); -extern PLpgSQL_nsitem *plpgsql_ns_lookup(const char *name, const char *nsname); +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); /* ----------