tree bdedbd4ddbd856aeb43cdb514065a86b7c2a88c6
parent 4d1d9acccfd63e494cda58054baf5113972ffacb
author Heschi Kreinick <heschi@google.com> 1595358906 -0400
committer Heschi Kreinick <heschi@google.com> 1595957711 +0000

internal/lsp: replace ParseGoHandle with concrete data

ParseGoHandles serve two purposes: they pin cache entries so that
redundant calculations are cached, and they allow users to obtain the
actual parsed AST. The former is an implementation detail, and the
latter turns out to just be an annoyance.

Parsed Go files are obtained from two places. By far the most common is
from a type checked package. But a type checked package must by
definition have already parsed all the files it contains, so the PGH
is already computed and cannot have failed. Type checked packages can
simply return the parsed file without requiring a separate Check
operation. We do want to pin the cache entries in this case, which I've
done by holding on to the PGH in cache.pkg.

There are some cases where we directly parse a file, such as for the
FoldingRange LSP call, which doesn't need type information. Those parses
can actually fail, so we do need an error check. But we don't need the
PGH; in all cases we are immediately using and discarding it.

So it turns out we don't actually need the PGH type at all, at least not
in the public API. Instead, we can pass around a concrete struct that
has the various pieces of data directly available.

This uncovered a bug in typeCheck: it should fail if it encounters any
real errors.

Change-Id: I203bf2dd79d5d65c01392d69c2cf4f7744fde7fc
Reviewed-on: https://go-review.googlesource.com/c/tools/+/244021
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rebecca Stambler <rstambler@golang.org>