diff options
Diffstat (limited to 'vendor/github.com/polyfloyd')
3 files changed, 310 insertions, 0 deletions
diff --git a/vendor/github.com/polyfloyd/go-errorlint/LICENSE b/vendor/github.com/polyfloyd/go-errorlint/LICENSE new file mode 100644 index 000000000..b7f88cf1c --- /dev/null +++ b/vendor/github.com/polyfloyd/go-errorlint/LICENSE @@ -0,0 +1,21 @@ +The MIT License (MIT) + +Copyright (c) 2019 polyfloyd + +Permission is hereby granted, free of charge, to any person obtaining a copy +of this software and associated documentation files (the "Software"), to deal +in the Software without restriction, including without limitation the rights +to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +copies of the Software, and to permit persons to whom the Software is +furnished to do so, subject to the following conditions: + +The above copyright notice and this permission notice shall be included in all +copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +SOFTWARE. diff --git a/vendor/github.com/polyfloyd/go-errorlint/errorlint/analysis.go b/vendor/github.com/polyfloyd/go-errorlint/errorlint/analysis.go new file mode 100644 index 000000000..20d1c1e7c --- /dev/null +++ b/vendor/github.com/polyfloyd/go-errorlint/errorlint/analysis.go @@ -0,0 +1,44 @@ +package errorlint + +import ( + "flag" + "sort" + + "golang.org/x/tools/go/analysis" +) + +func NewAnalyzer() *analysis.Analyzer { + return &analysis.Analyzer{ + Name: "errorlint", + Doc: "Source code linter for Go software that can be used to find code that will cause problems with the error wrapping scheme introduced in Go 1.13.", + Run: run, + Flags: flagSet, + } +} + +var ( + flagSet flag.FlagSet + checkErrorf bool +) + +func init() { + flagSet.BoolVar(&checkErrorf, "errorf", false, "Check whether fmt.Errorf uses the %w verb for formatting errors. See the readme for caveats") +} + +func run(pass *analysis.Pass) (interface{}, error) { + lints := []Lint{} + if checkErrorf { + l := LintFmtErrorfCalls(pass.Fset, *pass.TypesInfo) + lints = append(lints, l...) + } + l := LintErrorComparisons(pass.Fset, *pass.TypesInfo) + lints = append(lints, l...) + l = LintErrorTypeAssertions(pass.Fset, *pass.TypesInfo) + lints = append(lints, l...) + sort.Sort(ByPosition(lints)) + + for _, l := range lints { + pass.Report(analysis.Diagnostic{Pos: l.Pos, Message: l.Message}) + } + return nil, nil +} diff --git a/vendor/github.com/polyfloyd/go-errorlint/errorlint/lint.go b/vendor/github.com/polyfloyd/go-errorlint/errorlint/lint.go new file mode 100644 index 000000000..e9f889c93 --- /dev/null +++ b/vendor/github.com/polyfloyd/go-errorlint/errorlint/lint.go @@ -0,0 +1,245 @@ +package errorlint + +import ( + "fmt" + "go/ast" + "go/constant" + "go/token" + "go/types" + "regexp" +) + +type Lint struct { + Message string + Pos token.Pos +} + +type ByPosition []Lint + +func (l ByPosition) Len() int { return len(l) } +func (l ByPosition) Swap(i, j int) { l[i], l[j] = l[j], l[i] } + +func (l ByPosition) Less(i, j int) bool { + return l[i].Pos < l[j].Pos +} + +func LintFmtErrorfCalls(fset *token.FileSet, info types.Info) []Lint { + lints := []Lint{} + for expr, t := range info.Types { + // Search for error expressions that are the result of fmt.Errorf + // invocations. + if t.Type.String() != "error" { + continue + } + call, ok := isFmtErrorfCallExpr(info, expr) + if !ok { + continue + } + + // Find all % fields in the format string. + formatVerbs, ok := printfFormatStringVerbs(info, call) + if !ok { + continue + } + + // For any arguments that are errors, check whether the wrapping verb + // is used. Only one %w verb may be used in a single format string at a + // time, so we stop after finding a correct %w. + var lintArg ast.Expr + args := call.Args[1:] + for i := 0; i < len(args) && i < len(formatVerbs); i++ { + if info.Types[args[i]].Type.String() != "error" && !isErrorStringCall(info, args[i]) { + continue + } + + if formatVerbs[i] == "%w" { + lintArg = nil + break + } + + if lintArg == nil { + lintArg = args[i] + } + } + if lintArg != nil { + lints = append(lints, Lint{ + Message: "non-wrapping format verb for fmt.Errorf. Use `%w` to format errors", + Pos: lintArg.Pos(), + }) + } + } + return lints +} + +// isErrorStringCall tests whether the expression is a string expression that +// is the result of an `(error).Error()` method call. +func isErrorStringCall(info types.Info, expr ast.Expr) bool { + if info.Types[expr].Type.String() == "string" { + if call, ok := expr.(*ast.CallExpr); ok { + if callSel, ok := call.Fun.(*ast.SelectorExpr); ok { + fun := info.Uses[callSel.Sel].(*types.Func) + return fun.Type().String() == "func() string" && fun.Name() == "Error" + } + } + } + return false +} + +func printfFormatStringVerbs(info types.Info, call *ast.CallExpr) ([]string, bool) { + if len(call.Args) <= 1 { + return nil, false + } + strLit, ok := call.Args[0].(*ast.BasicLit) + if !ok { + // Ignore format strings that are not literals. + return nil, false + } + formatString := constant.StringVal(info.Types[strLit].Value) + + // Naive format string argument verb. This does not take modifiers such as + // padding into account... + re := regexp.MustCompile(`%[^%]`) + return re.FindAllString(formatString, -1), true +} + +func isFmtErrorfCallExpr(info types.Info, expr ast.Expr) (*ast.CallExpr, bool) { + call, ok := expr.(*ast.CallExpr) + if !ok { + return nil, false + } + fn, ok := call.Fun.(*ast.SelectorExpr) + if !ok { + // TODO: Support fmt.Errorf variable aliases? + return nil, false + } + obj := info.Uses[fn.Sel] + + pkg := obj.Pkg() + if pkg != nil && pkg.Name() == "fmt" && obj.Name() == "Errorf" { + return call, true + } + return nil, false +} + +func LintErrorComparisons(fset *token.FileSet, info types.Info) []Lint { + lints := []Lint{} + + for expr := range info.Types { + // Find == and != operations. + binExpr, ok := expr.(*ast.BinaryExpr) + if !ok { + continue + } + if binExpr.Op != token.EQL && binExpr.Op != token.NEQ { + continue + } + // Comparing errors with nil is okay. + if isNilComparison(binExpr) { + continue + } + // Find comparisons of which one side is a of type error. + if !isErrorComparison(info, binExpr) { + continue + } + + lints = append(lints, Lint{ + Message: fmt.Sprintf("comparing with %s will fail on wrapped errors. Use errors.Is to check for a specific error", binExpr.Op), + Pos: binExpr.Pos(), + }) + } + + for scope := range info.Scopes { + // Find value switch blocks. + switchStmt, ok := scope.(*ast.SwitchStmt) + if !ok { + continue + } + // Check whether the switch operates on an error type. + if switchStmt.Tag == nil { + continue + } + tagType := info.Types[switchStmt.Tag] + if tagType.Type.String() != "error" { + continue + } + + lints = append(lints, Lint{ + Message: "switch on an error will fail on wrapped errors. Use errors.Is to check for specific errors", + Pos: switchStmt.Pos(), + }) + } + + return lints +} + +func isNilComparison(binExpr *ast.BinaryExpr) bool { + if ident, ok := binExpr.X.(*ast.Ident); ok && ident.Name == "nil" { + return true + } + if ident, ok := binExpr.Y.(*ast.Ident); ok && ident.Name == "nil" { + return true + } + return false +} + +func isErrorComparison(info types.Info, binExpr *ast.BinaryExpr) bool { + tx := info.Types[binExpr.X] + ty := info.Types[binExpr.Y] + return tx.Type.String() == "error" || ty.Type.String() == "error" +} + +func LintErrorTypeAssertions(fset *token.FileSet, info types.Info) []Lint { + lints := []Lint{} + + for expr := range info.Types { + // Find type assertions. + typeAssert, ok := expr.(*ast.TypeAssertExpr) + if !ok { + continue + } + + // Find type assertions that operate on values of type error. + if !isErrorTypeAssertion(info, typeAssert) { + continue + } + + lints = append(lints, Lint{ + Message: "type assertion on error will fail on wrapped errors. Use errors.As to check for specific errors", + Pos: typeAssert.Pos(), + }) + } + + for scope := range info.Scopes { + // Find type switches. + typeSwitch, ok := scope.(*ast.TypeSwitchStmt) + if !ok { + continue + } + + // Find the type assertion in the type switch. + var typeAssert *ast.TypeAssertExpr + switch t := typeSwitch.Assign.(type) { + case *ast.ExprStmt: + typeAssert = t.X.(*ast.TypeAssertExpr) + case *ast.AssignStmt: + typeAssert = t.Rhs[0].(*ast.TypeAssertExpr) + } + + // Check whether the type switch is on a value of type error. + if !isErrorTypeAssertion(info, typeAssert) { + continue + } + + lints = append(lints, Lint{ + Message: "type switch on error will fail on wrapped errors. Use errors.As to check for specific errors", + Pos: typeAssert.Pos(), + }) + } + + return lints +} + +func isErrorTypeAssertion(info types.Info, typeAssert *ast.TypeAssertExpr) bool { + t := info.Types[typeAssert.X] + return t.Type.String() == "error" +} |