blob: 286fcc30640ef87f63e799e70442d8e2cfff3c56 [file] [log] [blame]
// 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) {
// Because x and y are ambiguously live, they appear
// live throughout the function, to avoid being poisoned
// in GODEBUG=gcdead=1 mode.
print(0) // ERROR "live at call to printint: x y$"
if b == false {
print(0) // ERROR "live at call to printint: x y$"
return
}
if b {
var x *int
print(&x) // ERROR "live at call to printpointer: x y$"
print(&x) // ERROR "live at call to printpointer: x y$"
} else {
var y *int
print(&y) // ERROR "live at call to printpointer: x y$"
print(&y) // ERROR "live at call to printpointer: x y$"
}
print(0) // ERROR "live at call to printint: x y$" "x \(type \*int\) is ambiguously live" "y \(type \*int\) is ambiguously live"
}
// 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$"
}
}
func f5(b1 bool) {
var z **int
if b1 {
x := new(int)
*x = 42
z = &x
} else {
y := new(int)
*y = 54
z = &y
}
print(**z) // ERROR "live at call to printint: x y$" "x \(type \*int\) is ambiguously live" "y \(type \*int\) is ambiguously live"
}
// 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)
}
// liveness formerly confused by select, thinking runtime.selectgo
// can return to next instruction; it always jumps elsewhere.
// note that you have to use at least two cases in the select
// to get a true select; smaller selects compile to optimized helper functions.
var c chan *int
var b bool
// this used to have a spurious "live at entry to f11a: ~r0"
func f11a() *int {
select { // ERROR "live at call to selectgo: autotmp"
case <-c: // ERROR "live at call to selectrecv: autotmp"
return nil
case <-c: // ERROR "live at call to selectrecv: autotmp"
return nil
}
}
func f11b() *int {
p := new(int)
if b {
// At this point p is dead: the code here cannot
// get to the bottom of the function.
// This used to have a spurious "live at call to printint: p".
print(1) // nothing live here!
select { // ERROR "live at call to selectgo: autotmp"
case <-c: // ERROR "live at call to selectrecv: autotmp"
return nil
case <-c: // ERROR "live at call to selectrecv: autotmp"
return nil
}
}
println(*p)
return nil
}
func f11c() *int {
p := new(int)
if b {
// Unlike previous, the cases in this select fall through,
// so we can get to the println, so p is not dead.
print(1) // ERROR "live at call to printint: p"
select { // ERROR "live at call to newselect: p" "live at call to selectgo: autotmp.* p"
case <-c: // ERROR "live at call to selectrecv: autotmp.* p"
case <-c: // ERROR "live at call to selectrecv: autotmp.* p"
}
}
println(*p)
return nil
}
// similarly, select{} does not fall through.
// this used to have a spurious "live at entry to f12: ~r0".
func f12() *int {
if b {
select{}
} else {
return nil
}
}
// incorrectly placed VARDEF annotations can cause missing liveness annotations.
// this used to be missing the fact that s is live during the call to g13 (because it is
// needed for the call to h13).
func f13() {
s := "hello"
s = h13(s, g13(s)) // ERROR "live at call to g13: s"
}
func g13(string) string
func h13(string, string) string
// more incorrectly placed VARDEF.
func f14() {
x := g14()
print(&x) // ERROR "live at call to printpointer: x"
}
func g14() string
func f15() {
var x string
_ = &x
x = g15() // ERROR "live at call to g15: x"
print(x) // ERROR "live at call to printstring: x"
}
func g15() string
// Checking that various temporaries do not persist or cause
// ambiguously live values that must be zeroed.
// The exact temporary names are inconsequential but we are
// trying to check that there is only one at any given site,
// and also that none show up in "ambiguously live" messages.
var m map[string]int
func f16() {
if b {
delete(m, "hi") // ERROR "live at call to mapdelete: autotmp_[0-9]+$"
}
delete(m, "hi") // ERROR "live at call to mapdelete: autotmp_[0-9]+$"
delete(m, "hi") // ERROR "live at call to mapdelete: autotmp_[0-9]+$"
}
var m2s map[string]*byte
var m2 map[[2]string]*byte
var x2 [2]string
var bp *byte
func f17a() {
// value temporary only
if b {
m2[x2] = nil // ERROR "live at call to mapassign1: autotmp_[0-9]+$"
}
m2[x2] = nil // ERROR "live at call to mapassign1: autotmp_[0-9]+$"
m2[x2] = nil // ERROR "live at call to mapassign1: autotmp_[0-9]+$"
}
func f17b() {
// key temporary only
if b {
m2s["x"] = bp // ERROR "live at call to mapassign1: autotmp_[0-9]+$"
}
m2s["x"] = bp // ERROR "live at call to mapassign1: autotmp_[0-9]+$"
m2s["x"] = bp // ERROR "live at call to mapassign1: autotmp_[0-9]+$"
}
func f17c() {
// key and value temporaries
if b {
m2s["x"] = nil // ERROR "live at call to mapassign1: autotmp_[0-9]+ autotmp_[0-9]+$"
}
m2s["x"] = nil // ERROR "live at call to mapassign1: autotmp_[0-9]+ autotmp_[0-9]+$"
m2s["x"] = nil // ERROR "live at call to mapassign1: autotmp_[0-9]+ autotmp_[0-9]+$"
}
func g18() [2]string
func f18() {
// key temporary for mapaccess.
// temporary introduced by orderexpr.
var z *byte
if b {
z = m2[g18()] // ERROR "live at call to mapaccess1: autotmp_[0-9]+$"
}
z = m2[g18()] // ERROR "live at call to mapaccess1: autotmp_[0-9]+$"
z = m2[g18()] // ERROR "live at call to mapaccess1: autotmp_[0-9]+$"
print(z)
}
var ch chan *byte
func f19() {
// dest temporary for channel receive.
var z *byte
if b {
z = <-ch // ERROR "live at call to chanrecv1: autotmp_[0-9]+$"
}
z = <-ch // ERROR "live at call to chanrecv1: autotmp_[0-9]+$"
z = <-ch // ERROR "live at call to chanrecv1: autotmp_[0-9]+$"
print(z)
}
func f20() {
// src temporary for channel send
if b {
ch <- nil // ERROR "live at call to chansend1: autotmp_[0-9]+$"
}
ch <- nil // ERROR "live at call to chansend1: autotmp_[0-9]+$"
ch <- nil // ERROR "live at call to chansend1: autotmp_[0-9]+$"
}
func f21() {
// key temporary for mapaccess using array literal key.
var z *byte
if b {
z = m2[[2]string{"x", "y"}] // ERROR "live at call to mapaccess1: autotmp_[0-9]+$"
}
z = m2[[2]string{"x", "y"}] // ERROR "live at call to mapaccess1: autotmp_[0-9]+$"
z = m2[[2]string{"x", "y"}] // ERROR "live at call to mapaccess1: autotmp_[0-9]+$"
print(z)
}
func f23() {
// key temporary for two-result map access using array literal key.
var z *byte
var ok bool
if b {
z, ok = m2[[2]string{"x", "y"}] // ERROR "live at call to mapaccess2: autotmp_[0-9]+$"
}
z, ok = m2[[2]string{"x", "y"}] // ERROR "live at call to mapaccess2: autotmp_[0-9]+$"
z, ok = m2[[2]string{"x", "y"}] // ERROR "live at call to mapaccess2: autotmp_[0-9]+$"
print(z, ok)
}
func f24() {
// key temporary for map access using array literal key.
// value temporary too.
if b {
m2[[2]string{"x", "y"}] = nil // ERROR "live at call to mapassign1: autotmp_[0-9]+ autotmp_[0-9]+$"
}
m2[[2]string{"x", "y"}] = nil // ERROR "live at call to mapassign1: autotmp_[0-9]+ autotmp_[0-9]+$"
m2[[2]string{"x", "y"}] = nil // ERROR "live at call to mapassign1: autotmp_[0-9]+ autotmp_[0-9]+$"
}
// defer should not cause spurious ambiguously live variables
func f25(b bool) {
defer g25()
if b {
return
}
var x string
_ = &x
x = g15() // ERROR "live at call to g15: x"
print(x) // ERROR "live at call to printstring: x"
} // ERROR "live at call to deferreturn: x"
func g25()
// non-escaping ... slices passed to function call should die on return,
// so that the temporaries do not stack and do not cause ambiguously
// live variables.
func f26(b bool) {
if b {
print26(1,2,3) // ERROR "live at call to print26: autotmp_[0-9]+$"
}
print26(4,5,6) // ERROR "live at call to print26: autotmp_[0-9]+$"
print26(7,8,9) // ERROR "live at call to print26: autotmp_[0-9]+$"
println()
}
//go:noescape
func print26(...interface{})
// non-escaping closures passed to function call should die on return
func f27(b bool) {
x := 0
if b {
call27(func() {x++}) // ERROR "live at call to call27: autotmp_[0-9]+$"
}
call27(func() {x++}) // ERROR "live at call to call27: autotmp_[0-9]+$"
call27(func() {x++}) // ERROR "live at call to call27: autotmp_[0-9]+$"
println()
}
// but defer does escape to later execution in the function
func f27defer(b bool) {
x := 0
if b {
defer call27(func() {x++}) // ERROR "live at call to deferproc: autotmp_[0-9]+$" "live at call to deferreturn: autotmp_[0-9]+$"
}
defer call27(func() {x++}) // ERROR "live at call to deferproc: autotmp_[0-9]+ autotmp_[0-9]+$" "live at call to deferreturn: autotmp_[0-9]+ autotmp_[0-9]+$" "ambiguously live"
println() // ERROR "live at call to printnl: autotmp_[0-9]+ autotmp_[0-9]+$"
} // ERROR "live at call to deferreturn: autotmp_[0-9]+ autotmp_[0-9]+$"
// and newproc (go) escapes to the heap
func f27go(b bool) {
x := 0
if b {
go call27(func() {x++}) // ERROR "live at call to new: &x" "live at call to newproc: &x$"
}
go call27(func() {x++}) // ERROR "live at call to new: &x"
println()
}
//go:noescape
func call27(func())
// concatstring slice should die on return
var s1, s2, s3, s4, s5, s6, s7, s8, s9, s10 string
func f28(b bool) {
if b {
print(s1+s2+s3+s4+s5+s6+s7+s8+s9+s10) // ERROR "live at call to concatstrings: autotmp_[0-9]+$" "live at call to printstring: autotmp_[0-9]+$"
}
print(s1+s2+s3+s4+s5+s6+s7+s8+s9+s10) // ERROR "live at call to concatstrings: autotmp_[0-9]+$" "live at call to printstring: autotmp_[0-9]+$"
print(s1+s2+s3+s4+s5+s6+s7+s8+s9+s10) // ERROR "live at call to concatstrings: autotmp_[0-9]+$" "live at call to printstring: autotmp_[0-9]+$"
}
// map iterator should die on end of range loop
func f29(b bool) {
if b {
for k := range m { // ERROR "live at call to mapiterinit: autotmp_[0-9]+$" "live at call to mapiternext: autotmp_[0-9]+$"
print(k) // ERROR "live at call to printstring: autotmp_[0-9]+$"
}
}
for k := range m { // ERROR "live at call to mapiterinit: autotmp_[0-9]+$" "live at call to mapiternext: autotmp_[0-9]+$"
print(k) // ERROR "live at call to printstring: autotmp_[0-9]+$"
}
for k := range m { // ERROR "live at call to mapiterinit: autotmp_[0-9]+$" "live at call to mapiternext: autotmp_[0-9]+$"
print(k) // ERROR "live at call to printstring: autotmp_[0-9]+$"
}
}
// copy of array of pointers should die at end of range loop
var ptrarr [10]*int
func f30(b bool) {
// two live temps during print(p):
// the copy of ptrarr and the internal iterator pointer.
if b {
for _, p := range ptrarr {
print(p) // ERROR "live at call to printpointer: autotmp_[0-9]+ autotmp_[0-9]+$"
}
}
for _, p := range ptrarr {
print(p) // ERROR "live at call to printpointer: autotmp_[0-9]+ autotmp_[0-9]+$"
}
for _, p := range ptrarr {
print(p) // ERROR "live at call to printpointer: autotmp_[0-9]+ autotmp_[0-9]+$"
}
}
// conversion to interface should not leave temporary behind
func f31(b1, b2, b3 bool) {
if b1 {
g31("a") // ERROR "live at call to convT2E: autotmp_[0-9]+$" "live at call to g31: autotmp_[0-9]+$"
}
if b2 {
h31("b") // ERROR "live at call to new: autotmp_[0-9]+$" "live at call to convT2E: autotmp_[0-9]+ autotmp_[0-9]+$" "live at call to h31: autotmp_[0-9]+$"
}
if b3 {
panic("asdf") // ERROR "live at call to convT2E: autotmp_[0-9]+$" "live at call to panic: autotmp_[0-9]+$"
}
print(b3)
}
func g31(interface{})
func h31(...interface{})
// non-escaping partial functions passed to function call should die on return
type T32 int
func (t *T32) Inc() { // ERROR "live at entry"
*t++
}
var t32 T32
func f32(b bool) {
if b {
call32(t32.Inc) // ERROR "live at call to call32: autotmp_[0-9]+$"
}
call32(t32.Inc) // ERROR "live at call to call32: autotmp_[0-9]+$"
call32(t32.Inc) // ERROR "live at call to call32: autotmp_[0-9]+$"
}
//go:noescape
func call32(func())
// temporaries introduced during if conditions and && || expressions
// should die once the condition has been acted upon.
var m33 map[interface{}]int
func f33() {
if m33[nil] == 0 { // ERROR "live at call to mapaccess1: autotmp_[0-9]+$"
println()
return
} else {
println()
}
println()
}
func f34() {
if m33[nil] == 0 { // ERROR "live at call to mapaccess1: autotmp_[0-9]+$"
println()
return
}
println()
}
func f35() {
if m33[nil] == 0 && m33[nil] == 0 { // ERROR "live at call to mapaccess1: autotmp_[0-9]+$"
println()
return
}
println()
}
func f36() {
if m33[nil] == 0 || m33[nil] == 0 { // ERROR "live at call to mapaccess1: autotmp_[0-9]+$"
println()
return
}
println()
}
func f37() {
if (m33[nil] == 0 || m33[nil] == 0) && m33[nil] == 0 { // ERROR "live at call to mapaccess1: autotmp_[0-9]+$"
println()
return
}
println()
}
// select temps should disappear in the case bodies
var c38 chan string
func fc38() chan string
func fi38(int) *string
func fb38() *bool
func f38(b bool) {
// we don't care what temps are printed on the lines with output.
// we care that the println lines have no live variables
// and therefore no output.
if b {
select { // ERROR "live at call"
case <-fc38(): // ERROR "live at call"
println()
case fc38() <- *fi38(1): // ERROR "live at call"
println()
case *fi38(2) = <-fc38(): // ERROR "live at call"
println()
case *fi38(3), *fb38() = <-fc38(): // ERROR "live at call"
println()
}
println()
}
println()
}
// issue 8097: mishandling of x = x during return.
func f39() (x []int) {
x = []int{1}
println() // ERROR "live at call to printnl: x"
return x
}
func f39a() (x []int) {
x = []int{1}
println() // ERROR "live at call to printnl: x"
return
}
func f39b() (x [10]*int) {
x = [10]*int{new(int)} // ERROR "live at call to new: x"
println() // ERROR "live at call to printnl: x"
return x
}
func f39c() (x [10]*int) {
x = [10]*int{new(int)} // ERROR "live at call to new: x"
println() // ERROR "live at call to printnl: x"
return
}