When being used by the compiler, fix up types2 error messages to be more
like Go 1.17 compiler errors. In particular:
- add information about which method is missing when a type is not
assignable/convertible/etc. to an interface.
- add information about any existing method which has the same name,
but wrong type.
- add extra hint in the case that the source or destination type is a
pointer to an interface, rather than an interface.
- add extra hint "need type assertion" in the case that the source is
an interface that is implemented by the destination.
- the following change in the CL stack also adds information about any
existing method with a different name that only differs in case.
Include much of the new logic in a new common function
(*Checker).missingMethodReason().
types2 still adds a little more information in some cases then the Go
1.17 compiler. For example, it typically says "(value of type T)",
rather than "(type T)", where "value" could also be "constant",
"variable", etc.
I kept the types2 error messages almost all the same when types2 is not
used by the compiler. The only change (to reduce amount of compatibility
code) was to change "M method" phrasing in one case to "method M"
phrasing in one error message (which is the phrasing it uses in all
other cases). That is the reason that there are a few small changes in
types2/testdata/check/*.src.
Added new test test/fixedbugs/issue48471.go to test that the added
information is appearing correctly.
Also adjusted the pattern matching in a bunch of other
test/fixedbugs/*.go, now that types2 is producing error messages closer
to Go 1.17. Was able to remove a couple test files from the types2
exception list in run.go.
Updated #48471
Change-Id: I8af1eae6eb8a5541d8ea20b66f494e2e795e1956
Reviewed-on: https://go-review.googlesource.com/c/go/+/363436
Trust: Dan Scales <danscales@google.com>
Run-TryBot: Dan Scales <danscales@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
The test directory contains tests of the Go tool chain and runtime.
It includes black box tests, regression tests, and error output tests.
They are run as part of all.bash.
To run just these tests, execute:
../bin/go run run.go
To run just tests from specified files in this directory, execute:
../bin/go run run.go -- file1.go file2.go ...
Standard library tests should be written as regular Go tests in the appropriate package.
The tool chain and runtime also have regular Go tests in their packages.
The main reasons to add a new test to this directory are:
it is most naturally expressed using the test runner; or
it is also applicable to gccgo and other Go tool chains.
