commit db07eef77d537bafe05a8546860dcc0e64ef4d3d
author Sam Rawlins <srawlins@google.com> Wed Oct 27 01:43:21 2021 +0000
committer commit-bot@chromium.org <commit-bot@chromium.org> Wed Oct 27 01:43:21 2021 +0000
tree 38cd1151a3865ddffdd8e9d37416fe28e981ba9a
parent c46baff9c9a7d10b55d9039f0c75c11ecc41c32a

analyzer: visit local variables in resolution more safely

I'm preparing for the situation where an expression of (almost) any kind
could be wrapped with a generic function instantiation, and I was very
worried that there were a lot of cases like this:

    var localVariable = node.childNode;
    localVariable.accept(_resolver);
    // Do more with localVariable.

This is dangerous because localVariable may no longer be the same node
as `node.childNode`. I searched eerywhere I could for dangerous cases
like this. In some cases, I follow the middle statement with
`localVariable = node.childNode`, which is a common practice. In other
cases, the local variable was only referenced 2 or 3 times, and was
unnecessary. In other cases, I saw that the node strictly referred to
statements or other types of nodes, like a CatchClause. I am
reassured though that there really wasn't too much code like this.

I'd love to figure out how to enforce this statically, but haven't
found a good solution.

Change-Id: If38124dc2036b6f04879a065d66bf3ea73e68977
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/218184
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Commit-Queue: Samuel Rawlins <srawlins@google.com>