From: Tom Lane Date: Sat, 5 May 2018 20:23:07 +0000 (-0400) Subject: Fix bootstrap parser so that its keywords are unreserved words. X-Git-Tag: REL_11_BETA1~86 X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=d160882a17403d61bc04c5745493e027e60165ce;p=postgresql Fix bootstrap parser so that its keywords are unreserved words. Mark Dilger pointed out that the bootstrap parser does not allow any of its keywords to appear as column values unless they're quoted, and proposed dealing with that by quoting such values in genbki.pl. Looking closer, though, we also have that problem with respect to table, column, and type names appearing in the .bki file: the parser would fail if any of those matched any of its keywords. While so far there have been no conflicts (that I've heard of), this seems like a booby trap waiting to catch somebody. Rather than clutter genbki.pl with enough quoting logic to handle all that, let's make the bootstrap parser grow up a little bit and treat its keywords as unreserved. Experimentation shows that it's fairly easy to do so with the exception of _null_, which I don't have a big problem with keeping as a reserved word. The only change needed is that we can't have the "close" command take an optional table name: it has to either require or forbid the table name to avoid shift/reduce conflicts. genbki.pl has historically always included the table name, so I took that option. The implementation has bootscanner.l passing forward the string value of each keyword, in case bootparse.y needs that. This avoids needing to know the precise spelling of each keyword in bootparse.y, which is good because that's not always obvious from the token name. Discussion: https://postgr.es/m/3024FC91-DB6D-4732-B31C-DF772DF039A0@gmail.com --- diff --git a/doc/src/sgml/bki.sgml b/doc/src/sgml/bki.sgml index 5b557ffb7b..e3ba73a9a8 100644 --- a/doc/src/sgml/bki.sgml +++ b/doc/src/sgml/bki.sgml @@ -248,6 +248,8 @@ Null values are represented by _null_. + (Note that there is no way to create a value that is just that + string.) @@ -752,13 +754,13 @@ $ perl rewrite_dat_with_prokind.pl pg_proc.dat - close tablename + close tablename - Close the open table. The name of the table can be given as a - cross-check, but this is not required. + Close the open table. The name of the table must be given as a + cross-check. @@ -782,8 +784,8 @@ $ perl rewrite_dat_with_prokind.pl pg_proc.dat NULL values can be specified using the special key word - _null_. Values containing spaces must be - double quoted. + _null_. Values that do not look like + identifiers or digit strings must be double quoted. diff --git a/src/backend/bootstrap/bootparse.y b/src/backend/bootstrap/bootparse.y index 1ec0e5c8a9..4c72989cc2 100644 --- a/src/backend/bootstrap/bootparse.y +++ b/src/backend/bootstrap/bootparse.y @@ -105,6 +105,7 @@ static int num_columns_read = 0; List *list; IndexElem *ielem; char *str; + const char *kw; int ival; Oid oidval; } @@ -116,17 +117,17 @@ static int num_columns_read = 0; %type oidspec optoideq optrowtypeoid %token ID -%token OPEN XCLOSE XCREATE INSERT_TUPLE -%token XDECLARE INDEX ON USING XBUILD INDICES UNIQUE XTOAST %token COMMA EQUALS LPAREN RPAREN -%token OBJ_ID XBOOTSTRAP XSHARED_RELATION XWITHOUT_OIDS XROWTYPE_OID NULLVAL -%token XFORCE XNOT XNULL +/* NULLVAL is a reserved keyword */ +%token NULLVAL +/* All the rest are unreserved, and should be handled in boot_ident! */ +%token OPEN XCLOSE XCREATE INSERT_TUPLE +%token XDECLARE INDEX ON USING XBUILD INDICES UNIQUE XTOAST +%token OBJ_ID XBOOTSTRAP XSHARED_RELATION XWITHOUT_OIDS XROWTYPE_OID +%token XFORCE XNOT XNULL %start TopLevel -%nonassoc low -%nonassoc high - %% TopLevel: @@ -160,18 +161,12 @@ Boot_OpenStmt: ; Boot_CloseStmt: - XCLOSE boot_ident %prec low + XCLOSE boot_ident { do_start(); closerel($2); do_end(); } - | XCLOSE %prec high - { - do_start(); - closerel(NULL); - do_end(); - } ; Boot_CreateStmt: @@ -489,8 +484,28 @@ boot_column_val: { InsertOneNull(num_columns_read++); } ; -boot_ident : - ID { $$ = yylval.str; } +boot_ident: + ID { $$ = $1; } + | OPEN { $$ = pstrdup($1); } + | XCLOSE { $$ = pstrdup($1); } + | XCREATE { $$ = pstrdup($1); } + | INSERT_TUPLE { $$ = pstrdup($1); } + | XDECLARE { $$ = pstrdup($1); } + | INDEX { $$ = pstrdup($1); } + | ON { $$ = pstrdup($1); } + | USING { $$ = pstrdup($1); } + | XBUILD { $$ = pstrdup($1); } + | INDICES { $$ = pstrdup($1); } + | UNIQUE { $$ = pstrdup($1); } + | XTOAST { $$ = pstrdup($1); } + | OBJ_ID { $$ = pstrdup($1); } + | XBOOTSTRAP { $$ = pstrdup($1); } + | XSHARED_RELATION { $$ = pstrdup($1); } + | XWITHOUT_OIDS { $$ = pstrdup($1); } + | XROWTYPE_OID { $$ = pstrdup($1); } + | XFORCE { $$ = pstrdup($1); } + | XNOT { $$ = pstrdup($1); } + | XNULL { $$ = pstrdup($1); } ; %% diff --git a/src/backend/bootstrap/bootscanner.l b/src/backend/bootstrap/bootscanner.l index 1799757da2..739087b786 100644 --- a/src/backend/bootstrap/bootscanner.l +++ b/src/backend/bootstrap/bootscanner.l @@ -68,22 +68,35 @@ static int yyline = 1; /* line number for error reporting */ id [-A-Za-z0-9_]+ sid \"([^\"])*\" +/* + * Keyword tokens return the keyword text (as a constant string) in yylval.kw, + * just in case that's needed because we want to treat the keyword as an + * unreserved identifier. Note that _null_ is not treated as a keyword + * for this purpose; it's the one "reserved word" in the bootstrap syntax. + * + * Notice that all the keywords are case-sensitive, and for historical + * reasons some must be upper case. + * + * String tokens return a palloc'd string in yylval.str. + */ + %% -open { return OPEN; } +open { yylval.kw = "open"; return OPEN; } -close { return XCLOSE; } +close { yylval.kw = "close"; return XCLOSE; } -create { return XCREATE; } +create { yylval.kw = "create"; return XCREATE; } -OID { return OBJ_ID; } -bootstrap { return XBOOTSTRAP; } -"shared_relation" { return XSHARED_RELATION; } -"without_oids" { return XWITHOUT_OIDS; } -"rowtype_oid" { return XROWTYPE_OID; } -_null_ { return NULLVAL; } +OID { yylval.kw = "OID"; return OBJ_ID; } +bootstrap { yylval.kw = "bootstrap"; return XBOOTSTRAP; } +shared_relation { yylval.kw = "shared_relation"; return XSHARED_RELATION; } +without_oids { yylval.kw = "without_oids"; return XWITHOUT_OIDS; } +rowtype_oid { yylval.kw = "rowtype_oid"; return XROWTYPE_OID; } + +insert { yylval.kw = "insert"; return INSERT_TUPLE; } -insert { return INSERT_TUPLE; } +_null_ { return NULLVAL; } "," { return COMMA; } "=" { return EQUALS; } @@ -91,32 +104,31 @@ insert { return INSERT_TUPLE; } ")" { return RPAREN; } [\n] { yyline++; } -[\t] ; -" " ; - -^\#[^\n]* ; /* drop everything after "#" for comments */ - - -"declare" { return XDECLARE; } -"build" { return XBUILD; } -"indices" { return INDICES; } -"unique" { return UNIQUE; } -"index" { return INDEX; } -"on" { return ON; } -"using" { return USING; } -"toast" { return XTOAST; } -"FORCE" { return XFORCE; } -"NOT" { return XNOT; } -"NULL" { return XNULL; } +[\r\t ] ; + +^\#[^\n]* ; /* drop everything after "#" for comments */ + +declare { yylval.kw = "declare"; return XDECLARE; } +build { yylval.kw = "build"; return XBUILD; } +indices { yylval.kw = "indices"; return INDICES; } +unique { yylval.kw = "unique"; return UNIQUE; } +index { yylval.kw = "index"; return INDEX; } +on { yylval.kw = "on"; return ON; } +using { yylval.kw = "using"; return USING; } +toast { yylval.kw = "toast"; return XTOAST; } +FORCE { yylval.kw = "FORCE"; return XFORCE; } +NOT { yylval.kw = "NOT"; return XNOT; } +NULL { yylval.kw = "NULL"; return XNULL; } {id} { yylval.str = scanstr(yytext); return ID; } {sid} { - yytext[strlen(yytext)-1] = '\0'; /* strip off quotes */ + /* leading and trailing quotes are not passed to scanstr */ + yytext[strlen(yytext) - 1] = '\0'; yylval.str = scanstr(yytext+1); - yytext[strlen(yytext)] = '"'; /* restore quotes */ + yytext[strlen(yytext)] = '"'; /* restore yytext */ return ID; } @@ -124,8 +136,6 @@ insert { return INSERT_TUPLE; } elog(ERROR, "syntax error at line %d: unexpected character \"%s\"", yyline, yytext); } - - %% /* LCOV_EXCL_STOP */