Add staticcheck tool

vendor/honnef.co/go/tools/simple/s1004/s1004.go

@@ -0,0 +1,65 @@
+package s1004
+
+import (
+	"fmt"
+	"go/ast"
+	"go/token"
+
+	"honnef.co/go/tools/analysis/code"
+	"honnef.co/go/tools/analysis/edit"
+	"honnef.co/go/tools/analysis/facts/generated"
+	"honnef.co/go/tools/analysis/lint"
+	"honnef.co/go/tools/analysis/report"
+	"honnef.co/go/tools/pattern"
+
+	"golang.org/x/tools/go/analysis"
+)
+
+var SCAnalyzer = lint.InitializeAnalyzer(&lint.Analyzer{
+	Analyzer: &analysis.Analyzer{
+		Name:     "S1004",
+		Run:      CheckBytesCompare,
+		Requires: append([]*analysis.Analyzer{generated.Analyzer}, code.RequiredAnalyzers...),
+	},
+	Doc: &lint.RawDocumentation{
+		Title:   `Replace call to \'bytes.Compare\' with \'bytes.Equal\'`,
+		Before:  `if bytes.Compare(x, y) == 0 {}`,
+		After:   `if bytes.Equal(x, y) {}`,
+		Since:   "2017.1",
+		MergeIf: lint.MergeIfAny,
+	},
+})
+
+var Analyzer = SCAnalyzer.Analyzer
+
+var (
+	checkBytesCompareQ  = pattern.MustParse(`(BinaryExpr (CallExpr (Symbol "bytes.Compare") args) op@(Or "==" "!=") (IntegerLiteral "0"))`)
+	checkBytesCompareRe = pattern.MustParse(`(CallExpr (SelectorExpr (Ident "bytes") (Ident "Equal")) args)`)
+	checkBytesCompareRn = pattern.MustParse(`(UnaryExpr "!" (CallExpr (SelectorExpr (Ident "bytes") (Ident "Equal")) args))`)
+)
+
+func CheckBytesCompare(pass *analysis.Pass) (any, error) {
+	if pass.Pkg.Path() == "bytes" || pass.Pkg.Path() == "bytes_test" {
+		// the bytes package is free to use bytes.Compare as it sees fit
+		return nil, nil
+	}
+	for node, m := range code.Matches(pass, checkBytesCompareQ) {
+		args := report.RenderArgs(pass, m.State["args"].([]ast.Expr))
+		prefix := ""
+		if m.State["op"].(token.Token) == token.NEQ {
+			prefix = "!"
+		}
+
+		var fix analysis.SuggestedFix
+		switch tok := m.State["op"].(token.Token); tok {
+		case token.EQL:
+			fix = edit.Fix("Simplify use of bytes.Compare", edit.ReplaceWithPattern(pass.Fset, node, checkBytesCompareRe, m.State))
+		case token.NEQ:
+			fix = edit.Fix("Simplify use of bytes.Compare", edit.ReplaceWithPattern(pass.Fset, node, checkBytesCompareRn, m.State))
+		default:
+			panic(fmt.Sprintf("unexpected token %v", tok))
+		}
+		report.Report(pass, node, fmt.Sprintf("should use %sbytes.Equal(%s) instead", prefix, args), report.FilterGenerated(), report.Fixes(fix))
+	}
+	return nil, nil
+}