Add staticcheck tool

vendor/honnef.co/go/tools/staticcheck/sa2003/sa2003.go

@@ -0,0 +1,87 @@
+package sa2003
+
+import (
+	"fmt"
+	"go/types"
+
+	"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:     "SA2003",
+		Run:      run,
+		Requires: []*analysis.Analyzer{buildir.Analyzer},
+	},
+	Doc: &lint.RawDocumentation{
+		Title:    `Deferred \'Lock\' right after locking, likely meant to defer \'Unlock\' instead`,
+		Since:    "2017.1",
+		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 {
+		for _, block := range fn.Blocks {
+			instrs := irutil.FilterDebug(block.Instrs)
+			if len(instrs) < 2 {
+				continue
+			}
+			for i, ins := range instrs[:len(instrs)-1] {
+				call, ok := ins.(*ir.Call)
+				if !ok {
+					continue
+				}
+				if !irutil.IsCallToAny(call.Common(), "(*sync.Mutex).Lock", "(*sync.RWMutex).RLock") {
+					continue
+				}
+				nins, ok := instrs[i+1].(*ir.Defer)
+				if !ok {
+					continue
+				}
+				if !irutil.IsCallToAny(&nins.Call, "(*sync.Mutex).Lock", "(*sync.RWMutex).RLock") {
+					continue
+				}
+				if call.Common().Args[0] != nins.Call.Args[0] {
+					continue
+				}
+				name := shortCallName(call.Common())
+				alt := ""
+				switch name {
+				case "Lock":
+					alt = "Unlock"
+				case "RLock":
+					alt = "RUnlock"
+				}
+				report.Report(pass, nins, fmt.Sprintf("deferring %s right after having locked already; did you mean to defer %s?", name, alt))
+			}
+		}
+	}
+	return nil, nil
+}
+
+func shortCallName(call *ir.CallCommon) string {
+	if call.IsInvoke() {
+		return ""
+	}
+	switch v := call.Value.(type) {
+	case *ir.Function:
+		fn, ok := v.Object().(*types.Func)
+		if !ok {
+			return ""
+		}
+		return fn.Name()
+	case *ir.Builtin:
+		return v.Name()
+	}
+	return ""
+}