parser/parser.y: S/R conflicts 1->0.

[cznic]

state 696 // alter tableKwd after charsetKwd after [$end]

  484 TableOptListOpt: TableOptList .  [$end, ',', ';']
  486 TableOptList: TableOptList . TableOpt
  487 TableOptList: TableOptList . ',' TableOpt
   99 DefaultKwdOpt: .  [character, charsetKwd, collation]

    $end           reduce using rule 484 (TableOptListOpt)
    ','            shift, and goto state 699
    ';'            reduce using rule 484 (TableOptListOpt)
    autoIncrement  shift, and goto state 695
    character      reduce using rule 99 (DefaultKwdOpt)
    charsetKwd     reduce using rule 99 (DefaultKwdOpt)
    collation      reduce using rule 99 (DefaultKwdOpt)
    defaultKwd     shift, and goto state 654
    engine         shift, and goto state 693

    DefaultKwdOpt  goto state 694
    TableOpt       goto state 698

    conflict on ',', shift, and goto state 699, reduce using rule 484

(15:02) jnml@r550:~/src/github.com/cznic/tidb/parser$ goyacc -o /dev/null -cr parser.y
Parse table entries: 124933 of 382547, x 16 bits == 249866 bytes
(15:02) jnml@r550:~/src/github.com/cznic/tidb/parser$ 

WARNING: This PR removes the CommaOpt item in the CreateTableStmt production. Looking at MySQL docs, I believe it should not be accepted in this part of the grammar. However, if I'm mistaken, then you should not merge this PR and please let me know why CommaOpt is there - as the proper solution would have to be different (if it then exists at all).

[siddontang]

Thanks @cznic

We can execute create table if not exists t (c1 int); in MySQL command shell, so we support CommaOpt here.

Maybe we can remove the ; at first before parsing? @shenli

[cznic]

Comma is ',', not ';', that's a semicolon. IOW, now I'm confused even more ;-)

[siddontang]

Sorry for my fault. @cznic , I am wrong.
Comma is not allowed, I think too.

[shenli]

LGTM
@siddontang I think the CommaOpt should not be here. The parser parse text into statement list, and ';' will be treated as separator between statements. So it is not necessary to add ';' at the end of create statement rule.
Thanks a lot! @cznic

[coocood]

LGTM

Wow! All conflicts are resolved.
Great job, thank you.

[shenli]

I think we should add syntax conflict detection in Makefile to prevent future bugs. I will add an issue.