Add staticcheck tool

vendor/honnef.co/go/tools/staticcheck/sa5003/sa5003.go

@@ -0,0 +1,74 @@
+package sa5003
+
+import (
+	"go/ast"
+	"go/token"
+
+	"honnef.co/go/tools/analysis/code"
+	"honnef.co/go/tools/analysis/lint"
+	"honnef.co/go/tools/analysis/report"
+
+	"golang.org/x/tools/go/analysis"
+	"golang.org/x/tools/go/analysis/passes/inspect"
+)
+
+var SCAnalyzer = lint.InitializeAnalyzer(&lint.Analyzer{
+	Analyzer: &analysis.Analyzer{
+		Name:     "SA5003",
+		Run:      run,
+		Requires: []*analysis.Analyzer{inspect.Analyzer},
+	},
+	Doc: &lint.RawDocumentation{
+		Title: `Defers in infinite loops will never execute`,
+		Text: `Defers are scoped to the surrounding function, not the surrounding
+block. In a function that never returns, i.e. one containing an
+infinite loop, defers will never execute.`,
+		Since:    "2017.1",
+		Severity: lint.SeverityWarning,
+		MergeIf:  lint.MergeIfAny,
+	},
+})
+
+var Analyzer = SCAnalyzer.Analyzer
+
+func run(pass *analysis.Pass) (any, error) {
+	fn := func(node ast.Node) {
+		mightExit := false
+		var defers []ast.Stmt
+		loop := node.(*ast.ForStmt)
+		if loop.Cond != nil {
+			return
+		}
+		fn2 := func(node ast.Node) bool {
+			switch stmt := node.(type) {
+			case *ast.ReturnStmt:
+				mightExit = true
+				return false
+			case *ast.BranchStmt:
+				// TODO(dominikh): if this sees a break in a switch or
+				// select, it doesn't check if it breaks the loop or
+				// just the select/switch. This causes some false
+				// negatives.
+				if stmt.Tok == token.BREAK {
+					mightExit = true
+					return false
+				}
+			case *ast.DeferStmt:
+				defers = append(defers, stmt)
+			case *ast.FuncLit:
+				// Don't look into function bodies
+				return false
+			}
+			return true
+		}
+		ast.Inspect(loop.Body, fn2)
+		if mightExit {
+			return
+		}
+		for _, stmt := range defers {
+			report.Report(pass, stmt, "defers in this infinite loop will never run")
+		}
+	}
+	code.Preorder(pass, fn, (*ast.ForStmt)(nil))
+	return nil, nil
+}