go1.18 support

[ldez]

go1.18 is released but the core tooling (golang.org/x/tools) is not ready.

The Go version should be defined in the configuration:

run:
    go: 1.18

If you set the version to go1.18, the following linters will be inactive:

• bodyclose
• contextcheck
• gosimple
• nilerr
• noctx
• rowserrcheck
• sqlclosecheck
• staticcheck
• stylecheck
• tparallel
• unparam
• unused
• wastedassign

Notes:

• some analyzers of govet (nilness and unusedwrite) don't work with generics and must be disabled by hand
• some rules in go-critic (hugeParam, rangeValCopy, typeDefFirst) don't work with generics and must be disabled by hand

Also, I can't guarantee that there are no hidden problems, I tested golangci-lint on a codebase containing different use of generics but this is not exhaustive.

Take a look at #2649 for details.

[ernado]

Hey @ldez, any help required?

[ldez]

@ernado not really because the main problem is SSA.

The linters that use SSA cannot work without the support of generics in golang.org/x/tools.

[bombsimon]

LGTM!

[peczenyj]

Hello,

I think we should also omit the linter structcheck on go1.18 mode

A code like this:

type Foo[T any] struct {
	t T
}

func (f Foo[T]) Get() T {
	return f.t
}

will trigger

foo/bar.go:68:2: `t` is unused (structcheck)
	t T

but will execute fine if there is no generic type in the structure

[ldez]

@peczenyj #2649 (comment)