// errorcheck -0 -l -live // Copyright 2014 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. package main func f1() { var x *int print(&x) // ERROR "live at call to printpointer: x$" print(&x) // ERROR "live at call to printpointer: x$" } func f2(b bool) { if b { print(0) // nothing live here return } var x *int print(&x) // ERROR "live at call to printpointer: x$" print(&x) // ERROR "live at call to printpointer: x$" } func f3(b bool) { print(0) if b == false { print(0) // nothing live here return } if b { var x *int print(&x) // ERROR "live at call to printpointer: x$" print(&x) // ERROR "live at call to printpointer: x$" } else { var y *int print(&y) // ERROR "live at call to printpointer: y$" print(&y) // ERROR "live at call to printpointer: y$" } print(0) // ERROR "live at call to printint: x y$" } // The old algorithm treated x as live on all code that // could flow to a return statement, so it included the // function entry and code above the declaration of x // but would not include an indirect use of x in an infinite loop. // Check that these cases are handled correctly. func f4(b1, b2 bool) { // x not live here if b2 { print(0) // x not live here return } var z **int x := new(int) *x = 42 z = &x print(**z) // ERROR "live at call to printint: x z$" if b2 { print(1) // ERROR "live at call to printint: x$" return } for { print(**z) // ERROR "live at call to printint: x z$" } } func f5(b1 bool) { var z **int if b1 { x := new(int) *x = 42 z = &x } else { y := new(int) *y = 54 z = &y } print(**z) // ERROR "live at call to printint: x y$" } // confusion about the _ result used to cause spurious "live at entry to f6: _". func f6() (_, y string) { y = "hello" return } // confusion about addressed results used to cause "live at entry to f7: x". func f7() (x string) { _ = &x x = "hello" return } // ignoring block returns used to cause "live at entry to f8: x, y". func f8() (x, y string) { return g8() } func g8() (string, string) // ignoring block assignments used to cause "live at entry to f9: x" // issue 7205 var i9 interface{} func f9() bool { g8() x := i9 return x != 99 } // liveness formerly confused by UNDEF followed by RET, // leading to "live at entry to f10: ~r1" (unnamed result). func f10() string { panic(1) }