diff --git a/go/analysis/passes/printf/printf.go b/go/analysis/passes/printf/printf.go index 80db95c8..9fa0a1c6 100644 --- a/go/analysis/passes/printf/printf.go +++ b/go/analysis/passes/printf/printf.go @@ -843,7 +843,22 @@ func recursiveStringer(pass *analysis.Pass, e ast.Expr) bool { } // Is the expression e within the body of that String method? - return stringMethod.Pkg() == pass.Pkg && stringMethod.Scope().Contains(e.Pos()) + if stringMethod.Pkg() != pass.Pkg || !stringMethod.Scope().Contains(e.Pos()) { + return false + } + + // Is it the receiver r, or &r? + recv := stringMethod.Type().(*types.Signature).Recv() + if recv == nil { + return false + } + if u, ok := e.(*ast.UnaryExpr); ok && u.Op == token.AND { + e = u.X // strip off & from &r + } + if id, ok := e.(*ast.Ident); ok { + return pass.TypesInfo.Uses[id] == recv + } + return false } // isFunctionValue reports whether the expression is a function as opposed to a function call. diff --git a/go/analysis/passes/printf/testdata/src/a/a.go b/go/analysis/passes/printf/testdata/src/a/a.go index 603179bc..970b5122 100644 --- a/go/analysis/passes/printf/testdata/src/a/a.go +++ b/go/analysis/passes/printf/testdata/src/a/a.go @@ -514,6 +514,19 @@ func (p *recursivePtrStringer) String() string { return fmt.Sprintln(p) // want "Sprintln arg p causes recursive call to String method" } +type cons struct { + car int + cdr *cons +} + +func (cons *cons) String() string { + if cons == nil { + return "nil" + } + _ = fmt.Sprint(cons.cdr) // don't want "recursive call" diagnostic + return fmt.Sprintf("(%d . %v)", cons.car, cons.cdr) // don't want "recursive call" diagnostic +} + type BoolFormatter bool func (*BoolFormatter) Format(fmt.State, rune) {