code review 213750043: compiler: Do not declare type switch variable outside c...

compiler: Do not declare type switch variable outside case statements. For expressions containing a TypeSwitchGuard with a short variable declaration e.g. var := x.(type), the spec says that var is declared at the beginning of the implicit block for each in each clause. Previously, var was declared in the block for the switch statement and each implicit block, which led to errors if the type case clause referenced a type with a similar name as the declared variable. Fixes golang/go#10047.

[cmang, 2015-03-04 21:45:03]

Hello iant@golang.org (cc: gofrontend-dev@googlegroups.com), I'd like you to review this change to https://code.google.com/p/gofrontend

[iant, 2015-03-04 22:06:31]

https://codereview.appspot.com/213750043/diff/40001/go/parse.cc File go/parse.cc (right): https://codereview.appspot.com/213750043/diff/40001/go/parse.cc#newcode4609 go/parse.cc:4609: this->gogo_->current_block()->add_statement(switch_temp); Just use this->gogo_->add_statement(switch_temp);

[cmang, 2015-03-04 22:09:49]

https://codereview.appspot.com/213750043/diff/40001/go/parse.cc File go/parse.cc (right): https://codereview.appspot.com/213750043/diff/40001/go/parse.cc#newcode4609 go/parse.cc:4609: this->gogo_->current_block()->add_statement(switch_temp); On 2015/03/04 22:06:30, iant wrote: > Just use > this->gogo_->add_statement(switch_temp); Done.

[iant, 2015-03-05 02:14:13]

https://codereview.appspot.com/213750043/diff/40001/go/parse.cc File go/parse.cc (right): https://codereview.appspot.com/213750043/diff/40001/go/parse.cc#newcode4603 go/parse.cc:4603: "no new variables on left side of %<:=%>"); Since we are now using the name later, we should clear the name here to avoid followon errors.

[cmang, 2015-03-05 17:03:29]

https://codereview.appspot.com/213750043/diff/40001/go/parse.cc File go/parse.cc (right): https://codereview.appspot.com/213750043/diff/40001/go/parse.cc#newcode4603 go/parse.cc:4603: "no new variables on left side of %<:=%>"); On 2015/03/05 02:14:13, iant wrote: > Since we are now using the name later, we should clear the name here to avoid > followon errors. Done.

[iant, 2015-03-06 00:19:37]

LGTM

[iant, 2015-03-06 00:23:01]

*** Submitted as https://code.google.com/p/gofrontend/source/detail?r=a58c55f615d7 *** compiler: Do not declare type switch variable outside case statements. For expressions containing a TypeSwitchGuard with a short variable declaration e.g. var := x.(type), the spec says that var is declared at the beginning of the implicit block for each in each clause. Previously, var was declared in the block for the switch statement and each implicit block, which led to errors if the type case clause referenced a type with a similar name as the declared variable. Fixes golang/go#10047. LGTM=iant R=iant CC=gofrontend-dev https://codereview.appspot.com/213750043 Committer: Ian Lance Taylor <iant@golang.org>