Add staticcheck tool

vendor/honnef.co/go/tools/staticcheck/sa5000/sa5000.go

@@ -0,0 +1,49 @@
+package sa5000
+
+import (
+	"honnef.co/go/tools/analysis/lint"
+	"honnef.co/go/tools/analysis/report"
+	"honnef.co/go/tools/go/ir"
+	"honnef.co/go/tools/go/ir/irutil"
+	"honnef.co/go/tools/internal/passes/buildir"
+
+	"golang.org/x/tools/go/analysis"
+)
+
+var SCAnalyzer = lint.InitializeAnalyzer(&lint.Analyzer{
+	Analyzer: &analysis.Analyzer{
+		Name:     "SA5000",
+		Run:      run,
+		Requires: []*analysis.Analyzer{buildir.Analyzer},
+	},
+	Doc: &lint.RawDocumentation{
+		Title:    `Assignment to nil map`,
+		Since:    "2017.1",
+		Severity: lint.SeverityError,
+		MergeIf:  lint.MergeIfAny,
+	},
+})
+
+var Analyzer = SCAnalyzer.Analyzer
+
+func run(pass *analysis.Pass) (any, error) {
+	for _, fn := range pass.ResultOf[buildir.Analyzer].(*buildir.IR).SrcFuncs {
+		for _, block := range fn.Blocks {
+			for _, ins := range block.Instrs {
+				mu, ok := ins.(*ir.MapUpdate)
+				if !ok {
+					continue
+				}
+				c, ok := irutil.Flatten(mu.Map).(*ir.Const)
+				if !ok {
+					continue
+				}
+				if c.Value != nil {
+					continue
+				}
+				report.Report(pass, mu, "assignment to nil map")
+			}
+		}
+	}
+	return nil, nil
+}