Add staticcheck tool

vendor/honnef.co/go/tools/staticcheck/sa9003/sa9003.go

@@ -0,0 +1,62 @@
+package sa9003
+
+import (
+	"go/ast"
+
+	"golang.org/x/tools/go/analysis"
+	"honnef.co/go/tools/analysis/facts/generated"
+	"honnef.co/go/tools/analysis/lint"
+	"honnef.co/go/tools/analysis/report"
+	"honnef.co/go/tools/go/ir/irutil"
+	"honnef.co/go/tools/internal/passes/buildir"
+)
+
+var SCAnalyzer = lint.InitializeAnalyzer(&lint.Analyzer{
+	Analyzer: &analysis.Analyzer{
+		Name:     "SA9003",
+		Run:      run,
+		Requires: []*analysis.Analyzer{buildir.Analyzer, generated.Analyzer},
+	},
+	Doc: &lint.RawDocumentation{
+		Title:      `Empty body in an if or else branch`,
+		Since:      "2017.1",
+		NonDefault: true,
+		Severity:   lint.SeverityWarning,
+		MergeIf:    lint.MergeIfAny,
+	},
+})
+
+var Analyzer = SCAnalyzer.Analyzer
+
+func run(pass *analysis.Pass) (any, error) {
+	for _, fn := range pass.ResultOf[buildir.Analyzer].(*buildir.IR).SrcFuncs {
+		if fn.Source() == nil {
+			continue
+		}
+		if irutil.IsExample(fn) {
+			continue
+		}
+		cb := func(node ast.Node) bool {
+			ifstmt, ok := node.(*ast.IfStmt)
+			if !ok {
+				return true
+			}
+			if ifstmt.Else != nil {
+				b, ok := ifstmt.Else.(*ast.BlockStmt)
+				if !ok || len(b.List) != 0 {
+					return true
+				}
+				report.Report(pass, ifstmt.Else, "empty branch", report.FilterGenerated(), report.ShortRange())
+			}
+			if len(ifstmt.Body.List) != 0 {
+				return true
+			}
+			report.Report(pass, ifstmt, "empty branch", report.FilterGenerated(), report.ShortRange())
+			return true
+		}
+		if source := fn.Source(); source != nil {
+			ast.Inspect(source, cb)
+		}
+	}
+	return nil, nil
+}