cmd/vet: add waitgroup analyzer

+ relnote

Fixes #18022

Change-Id: I92d1939e9d9f16824655c6c909a5f58ed9500014
Reviewed-on: https://go-review.googlesource.com/c/go/+/661519
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Commit-Queue: Alan Donovan <adonovan@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Auto-Submit: Alan Donovan <adonovan@google.com>

doc/next/3-tools.md

@@ -24,3 +24,12 @@ specifying the command's current version.
 
 ### Cgo {#cgo}
 
+### Vet {#vet}
+
+<!-- go.dev/issue/18022 -->
+
+The `go vet` command now includes the
+[waitgroup](https://pkg.go.dev/golang.org/x/tools/go/analysis/passes/waitgroup)
+analyzer, which reports misplaced calls to [sync.WaitGroup.Add].
+
+

src/cmd/go/internal/test/flagdefs.go

@@ -77,4 +77,5 @@ var passAnalyzersToVet = map[string]bool{
 	"unreachable":      true,
 	"unsafeptr":        true,
 	"unusedresult":     true,
+	"waitgroup":        true,
 }

src/cmd/vet/doc.go

@@ -59,6 +59,7 @@ To list the available checks, run "go tool vet help":
 	unreachable      check for unreachable code
 	unsafeptr        check for invalid conversions of uintptr to unsafe.Pointer
 	unusedresult     check for unused results of calls to some functions
+	waitgroup        check for misuses of sync.WaitGroup
 
 For details and flags of a particular check, such as printf, run "go tool vet help printf".
 

src/cmd/vet/main.go

@@ -44,7 +44,7 @@ import (
 	"golang.org/x/tools/go/analysis/passes/unreachable"
 	"golang.org/x/tools/go/analysis/passes/unsafeptr"
 	"golang.org/x/tools/go/analysis/passes/unusedresult"
-	_ "golang.org/x/tools/go/analysis/passes/waitgroup" // vendoring placeholder
+	"golang.org/x/tools/go/analysis/passes/waitgroup"
 )
 
 func main() {
@@ -86,6 +86,7 @@ func main() {
 		unreachable.Analyzer,
 		unsafeptr.Analyzer,
 		unusedresult.Analyzer,
+		waitgroup.Analyzer,
 	)
 
 	// It's possible that unitchecker will exit early. In

src/cmd/vet/vet_test.go

@@ -70,8 +70,8 @@ func TestVet(t *testing.T) {
 		"unmarshal",
 		"unsafeptr",
 		"unused",
+		"waitgroup",
 	} {
-		pkg := pkg
 		t.Run(pkg, func(t *testing.T) {
 			t.Parallel()