>>>>> "Andrew" == Andrew Gierth <and...@tao11.riddles.org.uk> writes:
Andrew> select f(a =>-1); -- ERROR: column "a" does not exist
Andrew> I guess the fix is to extend the existing special case code
Andrew> that checks for one character left after removing trailing [+-]
Andrew> and also check for the two-character ops "<>" ">=" "<=" "=>"
Andrew> "!=".
Patch attached.
This fixes two bugs: first the mis-lexing of two-char ops as mentioned
originally; second, the O(N^3) lexing time of strings of - or +
characters is reduced to O(N^2) (in practice it's better than O(N^2)
once N gets large because the bison stack gets blown out, ending the
loop early).
--
Andrew (irc:RhodiumToad)
diff --git a/src/backend/parser/scan.l b/src/backend/parser/scan.l
index 0cd782827a..cc855ffb1c 100644
--- a/src/backend/parser/scan.l
+++ b/src/backend/parser/scan.l
@@ -885,20 +885,34 @@ other .
* to forbid operator names like '?-' that could not be
* sequences of SQL operators.
*/
- while (nchars > 1 &&
- (yytext[nchars - 1] == '+' ||
- yytext[nchars - 1] == '-'))
+ if (nchars > 1 &&
+ (yytext[nchars - 1] == '+' ||
+ yytext[nchars - 1] == '-'))
{
int ic;
for (ic = nchars - 2; ic >= 0; ic--)
{
- if (strchr("~!@#^&|`?%", yytext[ic]))
+ char c = yytext[ic];
+ if (c == '~' || c == '!' || c == '@' ||
+ c == '#' || c == '^' || c == '&' ||
+ c == '|' || c == '`' || c == '?' ||
+ c == '%')
break;
}
- if (ic >= 0)
- break; /* found a char that makes it OK */
- nchars--; /* else remove the +/-, and check again */
+ if (ic < 0)
+ {
+ /*
+ * didn't find a qualifying character, so remove
+ * all trailing [+-]
+ */
+ for (nchars--;
+ nchars > 1 &&
+ (yytext[nchars - 1] == '+' ||
+ yytext[nchars - 1] == '-');
+ nchars--)
+ continue;
+ }
}
SET_YYLLOC();
@@ -916,6 +930,25 @@ other .
if (nchars == 1 &&
strchr(",()[].;:+-*/%^<>=", yytext[0]))
return yytext[0];
+ /*
+ * Likewise, if what we have left is two chars, and
+ * those match the tokens ">=", "<=", "=>", "<>" or
+ * "!=", then we must return the sppropriate token
+ * rather than the generic Op.
+ */
+ if (nchars == 2)
+ {
+ if (yytext[0] == '=' && yytext[1] == '>')
+ return EQUALS_GREATER;
+ if (yytext[0] == '>' && yytext[1] == '=')
+ return GREATER_EQUALS;
+ if (yytext[0] == '<' && yytext[1] == '=')
+ return LESS_EQUALS;
+ if (yytext[0] == '<' && yytext[1] == '>')
+ return NOT_EQUALS;
+ if (yytext[0] == '!' && yytext[1] == '=')
+ return NOT_EQUALS;
+ }
}
/*
