Support of generics

[ldez]

Since the version v1.45.0 golangci-lint supports go1.18.

But some linters don't work with generics, golangci-lint disable those linters automatically with go1.18.

Since v1.45.1, golangci-lint can detect the Go version used by a project.

To get the Go version golangci-lint will use, in order:

• the Go version defined by the CLI flag, ex: --go=1.18
• the Go version defined in the configuration file, ex:

  run:
    go: '1.18'

• the Go version defined in the go.mod, ex;

  module github.com/org/my-project
  
  go 1.18

• Go version defined by the env var GOVERSION
• fallback on go1.17.

Notes:

• some rules in go-critic (externalErrorReassign) don't work with generics and must be disabled by hand
• if you are not using generics (and your dependencies) you can use the following configuration:

  run:
    go: '1.17'

---

The keyword any works well and produces no error (it's expected because it's just a type alias)

---

The problem with SSA is now fixed but some linters need to update their code base to handle generics.

About the linters:

• for go-critic, there is an existing issue Support generics for Go 1.18 go-critic/go-critic#1193

---

Linter issues: (checked if the problems are solved)

• govet(nilness,unusedwrite)
• staticcheck, stylecheck, gosimple, unused
• bodyclose
• contextcheck
• nilerr
• noctx
• rowserrcheck
• sqlclosecheck
• tparallel
• wastedassign
• unparam
• struccheck: Deprecated
• go-critic(externalErrorReassign)

---

The binary compiled with go1.17 doesn't work when running on go1.18:

$ golangci-lint run
panic: load embedded ruleguard rules: rules/rules.go:13: can't load fmt

goroutine 1 [running]:
github.com/go-critic/go-critic/checkers.init.22()
        github.com/go-critic/go-critic@v0.6.2/checkers/embedded_rules.go:46 +0x4b4

---

Compatibility table

🟢️: means that the linter seems to work, but it's not 100% sure, it needs to be tested on more go1.18 code.
🟠: means that the linter works partially.
🔴: means that the linter panic.

The current state:

Linter	State	Problem
asciicheck	🟢️
bidichk	🟢️
bodyclose	🟢️
containedctx	🟢️
contextcheck	🟢️
cyclop	🟢️
deadcode	🟢️
decorder	🟢️
depguard	🟢️
dogsled	🟢️
dupl	🟢️
durationcheck	🟢️
errcheck	🟢️
errchkjson	🟢️
errname	🟢️
errname	🟢️
errorlint	🟢️
exhaustive	🟢️
exhaustivestruct	🟢️
exportloopref	🟢️
forbidigo	🟢️
forcetypeassert	🟢️
funlen	🟢️
gci	🟢️
gochecknoglobals	🟢️
gochecknoinits	🟢️
gocognit	🟢️
goconst	🟢️
gocritic	🟠	type assertion
gocyclo	🟢️
godot	🟢️
godox	🟢️
goerr113	🟢️
gofmt	🟢️
gofumpt	🟢️
goheader	🟢️
goimports	🟢️
gomnd	🟢️
gomoddirectives	🟢️
gomodguard	🟢️
goprintffuncname	🟢️
gosec	🟢️
gosimple	🟢️
govet	🟢️
grouper	🟢️
ifshort	🟢️
importas	🟢️
ineffassign	🟢️
ireturn	🟢️
lll	🟢️
maintidx	🟢️
makezero	🟢️
misspell	🟢️
nakedret	🟢️
nestif	🟢️
nilerr	🟢️
nilnil	🟢️
nlreturn	🟢️
noctx	🟢️
nolintlint	🟢️
paralleltest	🟢️
prealloc	🟢️
predeclared	🟢️
promlinter	🟢️
revive	🟢️
rowserrcheck	🟠	some elements are not detected
sqlclosecheck	🟠	some elements are not detected
staticcheck	🟢️
structcheck	🟠	false positives
stylecheck	🟢️
tagliatelle	🟢️
tenv	🟢️
testpackage	🟢️
thelper	🟢️
tparallel	🟢️
typecheck	🟢️
unconvert	🟢️
unparam	🟢️
unused	🟢️
varcheck	🟢️
varnamelen	🟢️
wastedassign	🟠	some elements are not detected
whitespace	🟢️
wrapcheck	🟢️
wsl	🟢️

---

golangci-lint is a free and open-source project, built by people in their free time.
Also, the linter authors are an important part of golangci-lint.
If you use and appreciate golangci-lint please think to support us (golangci-lint maintainers and linters authors). ❤️

[ipfans]

I think we can pin this issue and lists all issues related to Go 1.18 support.

[ldez]

If someone want to help, you can contribute to solving this issue golang/go#48525

[vmatyus]

In our project after go version update to 1.18, the CI detected a lot of typecheck error. It is unable to load the types from ginkgo and also detects this module as unused:

"github.com/onsi/ginkgo" imported but not used (typecheck)
. "github.com/onsi/ginkgo"

undeclared name: `Describe` (typecheck)
var _ = Describe("Authenticator Unit Tests", func() {
        ^

[gucio321]

thats strange, I'm able to build golangci-lint with go1.18 without any issues however, I'm unable to run previously installed (before update to go 1.18) rpm 🤔

$ /usr/local/bin/golangci-lint run ./...
panic: load embedded ruleguard rules: rules/rules.go:13: can't load fmt

goroutine 1 [running]:
github.com/go-critic/go-critic/checkers.init.22()
	github.com/go-critic/go-critic@v0.6.2/checkers/embedded_rules.go:46 +0x4b4

after building linter by myself:

[giu (1) ]$ cd /tmp/golangci-lint/
[golangci-lint (0) ]$ go build -o golangci-lint cmd/golangci-lint/main.go 
[golangci-lint (0) ]$ cd ~/myproject
[myproject (0) ]$ /tmp/golangci-lint/golangci-lint run ./...
[myproject (0) ]$ 

[ldez]

@gucio321 take a look at #2438

[gucio321]

@gucio321 take a look at #2438

yah I swa it, but cannot understand what's going on... what is a difference between linter from here an this build with go-build?
and how to reproduce this issue?

[ldez]

Message for everyone

I'm working to find quick solutions (proposals and implementations), I will try to send a status update tomorrow.

I do my best, stay tuned.

[ldez]

All the linters are now fixed 🎉, we create a release soon ⏲️.

[MichaelSnowden]

I'm using version 1.52.2 (golangci-lint has version 1.52.2 built with go1.20.2 from da04413 on 2023-03-23T16:18:48Z), and I'm not able to use structcheck. The error message refers me to this issue.

$ golangci-lint run --no-config --disable-all -E structcheck 
WARN [runner] The linter 'structcheck' is deprecated (since v1.49.0) due to: The owner seems to have abandoned the linter. Replaced by unused. 
WARN [linters_context] structcheck is disabled because of generics. You can track the evolution of the generics support by following the https://github.com/golangci/golangci-lint/issues/2649. 
$

Is there a way to analyze and fix maligned structs using golangci-lint?

[james-d-elliott]

govet's fieldalignment analyzer should do this per the docs: https://golangci-lint.run/usage/linters/