go/types, types2: quote user-supplied names in error messages
Use `' quotes (as in `foo') to differentiate from Go quotes.
Quoting prevents confusion when user-supplied names alter
the meaning of the error message.
For instance, report
duplicate method `wanted'
rather than
duplicate method wanted
Exceptions:
- don't quote _:
`_' is ugly and not necessary
- don't quote after a ":":
undefined name: foo
- don't quote if the name is used correctly in a statement:
goto L jumps over variable declaration
Quoting is done with a helper function and can be centrally adjusted
and fine-tuned as needed.
Adjusted some test cases to explicitly include the quoted names.
Fixes #65790.
Change-Id: Icce667215f303ab8685d3e5cb00d540a2fd372ca
Reviewed-on: https://go-review.googlesource.com/c/go/+/571396
TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Robert Griesemer <gri@google.com> Reviewed-by: Robert Findley <rfindley@google.com>
Run-TryBot: Emmanuel Odeke <emmanuel@orijtech.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Robert Griesemer <gri@google.com>