We have known for a long time (see issue #1703) that the quality of our
CQL "syntax error" messages leave a lot to be desired, especially when
compared to Cassandra. This patch doesn't yet bring us great error
messages with great context - doing this isn't easy and it appears that
Antlr3's C++ runtime isn't as good as the Java one in this regard -
but this patch at least fixes **garbage** printed in some error messages.
Specifically, when the parser can deduce that a specific token is missing,
it used to print
line 1:83 missing ')' at '<missing '
After this patch we get rid of the meaningless string '<missing ':
line 1:83 : Missing ')'
Also, when the parser deduced that a specific token was unneeded, it
used to print:
line 1:83 extraneous input ')' expecting <invalid>
Now we got rid of this silly "<invalid>" and write just:
line 1:83 : Unexpected ')'
Refs #1703. I didn't yet marked that issue "fixed" because I think a
complete fix would also require printing the entire misparsed line and the
point of the parse failure. Scylla still prints a generic "Syntax Error"
in most cases now, and although the character number (83 in the above
example) can help, it's much more useful to see the actual failed
statement and where character 83 is.
Unfortunately some tests enshrine buggy error messages and had to be
fixed. Other tests enshrined strange text for a generic unexplained
error message, which used to say " : syntax error..." (note the two
spaces and elipses) and after this patch is " : Syntax error". So
these tests are changed. Another message, "no viable alternative at
input" is deliberately kept unchanged by this patch so as not to break
many more tests which enshrined this message.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Closes#13731
57ffbcbb22