mirror of
https://github.com/golang/go
synced 2024-11-18 07:14:44 -07:00
a0894ea5b5
Currently, escape analysis is able to record at most one dereference
when a parameter leaks to the heap; that is, at call sites, it can't
distinguish between any of these three functions:
func x1(p ****int) { sink = *p }
func x2(p ****int) { sink = **p }
func x3(p ****int) { sink = ***p }
Similarly, it's limited to recording parameter leaks to only the first
4 parameters, and only up to 6 dereferences.
All of these limitations are due to the awkward encoding scheme used
at the moment.
This CL replaces the encoding scheme with a simple [8]uint8 array,
which can handle up to the first 7 parameters, and up to 254
dereferences, which ought to be enough for anyone. And if not, it's
much more easily increased.
Shrinks export data size geometric mean for Kubernetes by 0.07%.
Fixes #33981.
Change-Id: I10a94b9accac9a0c91490e0d6d458316f5ca1e13
Reviewed-on: https://go-review.googlesource.com/c/go/+/197680
Reviewed-by: Cherry Zhang <cherryyz@google.com>
442 lines
9.1 KiB
Go
442 lines
9.1 KiB
Go
// errorcheck -0 -m -l
|
|
|
|
// Copyright 2015 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.
|
|
|
|
// Test escape analysis for function parameters.
|
|
|
|
// In this test almost everything is BAD except the simplest cases
|
|
// where input directly flows to output.
|
|
|
|
package escape
|
|
|
|
func zero() int { return 0 }
|
|
|
|
var sink interface{}
|
|
|
|
// in -> out
|
|
func param0(p *int) *int { // ERROR "leaking param: p to result ~r1"
|
|
return p
|
|
}
|
|
|
|
func caller0a() {
|
|
i := 0
|
|
_ = param0(&i)
|
|
}
|
|
|
|
func caller0b() {
|
|
i := 0 // ERROR "moved to heap: i$"
|
|
sink = param0(&i)
|
|
}
|
|
|
|
// in, in -> out, out
|
|
func param1(p1, p2 *int) (*int, *int) { // ERROR "leaking param: p1 to result ~r2" "leaking param: p2 to result ~r3"
|
|
return p1, p2
|
|
}
|
|
|
|
func caller1() {
|
|
i := 0 // ERROR "moved to heap: i$"
|
|
j := 0
|
|
sink, _ = param1(&i, &j)
|
|
}
|
|
|
|
// in -> other in
|
|
func param2(p1 *int, p2 **int) { // ERROR "leaking param: p1$" "p2 does not escape$"
|
|
*p2 = p1
|
|
}
|
|
|
|
func caller2a() {
|
|
i := 0 // ERROR "moved to heap: i$"
|
|
var p *int
|
|
param2(&i, &p)
|
|
_ = p
|
|
}
|
|
|
|
func caller2b() {
|
|
i := 0 // ERROR "moved to heap: i$"
|
|
var p *int
|
|
param2(&i, &p)
|
|
sink = p
|
|
}
|
|
|
|
func paramArraySelfAssign(p *PairOfPairs) { // ERROR "p does not escape"
|
|
p.pairs[0] = p.pairs[1] // ERROR "ignoring self-assignment in p.pairs\[0\] = p.pairs\[1\]"
|
|
}
|
|
|
|
func paramArraySelfAssignUnsafeIndex(p *PairOfPairs) { // ERROR "leaking param content: p"
|
|
// Function call inside index disables self-assignment case to trigger.
|
|
p.pairs[zero()] = p.pairs[1]
|
|
p.pairs[zero()+1] = p.pairs[1]
|
|
}
|
|
|
|
type PairOfPairs struct {
|
|
pairs [2]*Pair
|
|
}
|
|
|
|
type BoxedPair struct {
|
|
pair *Pair
|
|
}
|
|
|
|
type WrappedPair struct {
|
|
pair Pair
|
|
}
|
|
|
|
func leakParam(x interface{}) { // ERROR "leaking param: x"
|
|
sink = x
|
|
}
|
|
|
|
func sinkAfterSelfAssignment1(box *BoxedPair) { // ERROR "leaking param content: box"
|
|
box.pair.p1 = box.pair.p2 // ERROR "ignoring self-assignment in box.pair.p1 = box.pair.p2"
|
|
sink = box.pair.p2
|
|
}
|
|
|
|
func sinkAfterSelfAssignment2(box *BoxedPair) { // ERROR "leaking param content: box"
|
|
box.pair.p1 = box.pair.p2 // ERROR "ignoring self-assignment in box.pair.p1 = box.pair.p2"
|
|
sink = box.pair
|
|
}
|
|
|
|
func sinkAfterSelfAssignment3(box *BoxedPair) { // ERROR "leaking param content: box"
|
|
box.pair.p1 = box.pair.p2 // ERROR "ignoring self-assignment in box.pair.p1 = box.pair.p2"
|
|
leakParam(box.pair.p2)
|
|
}
|
|
|
|
func sinkAfterSelfAssignment4(box *BoxedPair) { // ERROR "leaking param content: box"
|
|
box.pair.p1 = box.pair.p2 // ERROR "ignoring self-assignment in box.pair.p1 = box.pair.p2"
|
|
leakParam(box.pair)
|
|
}
|
|
|
|
func selfAssignmentAndUnrelated(box1, box2 *BoxedPair) { // ERROR "leaking param content: box2" "box1 does not escape"
|
|
box1.pair.p1 = box1.pair.p2 // ERROR "ignoring self-assignment in box1.pair.p1 = box1.pair.p2"
|
|
leakParam(box2.pair.p2)
|
|
}
|
|
|
|
func notSelfAssignment1(box1, box2 *BoxedPair) { // ERROR "leaking param content: box2" "box1 does not escape"
|
|
box1.pair.p1 = box2.pair.p1
|
|
}
|
|
|
|
func notSelfAssignment2(p1, p2 *PairOfPairs) { // ERROR "leaking param content: p2" "p1 does not escape"
|
|
p1.pairs[0] = p2.pairs[1]
|
|
}
|
|
|
|
func notSelfAssignment3(p1, p2 *PairOfPairs) { // ERROR "leaking param content: p2" "p1 does not escape"
|
|
p1.pairs[0].p1 = p2.pairs[1].p1
|
|
}
|
|
|
|
func boxedPairSelfAssign(box *BoxedPair) { // ERROR "box does not escape"
|
|
box.pair.p1 = box.pair.p2 // ERROR "ignoring self-assignment in box.pair.p1 = box.pair.p2"
|
|
}
|
|
|
|
func wrappedPairSelfAssign(w *WrappedPair) { // ERROR "w does not escape"
|
|
w.pair.p1 = w.pair.p2 // ERROR "ignoring self-assignment in w.pair.p1 = w.pair.p2"
|
|
}
|
|
|
|
// in -> in
|
|
type Pair struct {
|
|
p1 *int
|
|
p2 *int
|
|
}
|
|
|
|
func param3(p *Pair) { // ERROR "p does not escape"
|
|
p.p1 = p.p2 // ERROR "param3 ignoring self-assignment in p.p1 = p.p2"
|
|
}
|
|
|
|
func caller3a() {
|
|
i := 0
|
|
j := 0
|
|
p := Pair{&i, &j}
|
|
param3(&p)
|
|
_ = p
|
|
}
|
|
|
|
func caller3b() {
|
|
i := 0 // ERROR "moved to heap: i$"
|
|
j := 0 // ERROR "moved to heap: j$"
|
|
p := Pair{&i, &j}
|
|
param3(&p)
|
|
sink = p // ERROR "p escapes to heap$"
|
|
}
|
|
|
|
// in -> rcvr
|
|
func (p *Pair) param4(i *int) { // ERROR "p does not escape$" "leaking param: i$"
|
|
p.p1 = i
|
|
}
|
|
|
|
func caller4a() {
|
|
i := 0 // ERROR "moved to heap: i$"
|
|
p := Pair{}
|
|
p.param4(&i)
|
|
_ = p
|
|
}
|
|
|
|
func caller4b() {
|
|
i := 0 // ERROR "moved to heap: i$"
|
|
p := Pair{}
|
|
p.param4(&i)
|
|
sink = p // ERROR "p escapes to heap$"
|
|
}
|
|
|
|
// in -> heap
|
|
func param5(i *int) { // ERROR "leaking param: i$"
|
|
sink = i
|
|
}
|
|
|
|
func caller5() {
|
|
i := 0 // ERROR "moved to heap: i$"
|
|
param5(&i)
|
|
}
|
|
|
|
// *in -> heap
|
|
func param6(i ***int) { // ERROR "leaking param content: i$"
|
|
sink = *i
|
|
}
|
|
|
|
func caller6a() {
|
|
i := 0 // ERROR "moved to heap: i$"
|
|
p := &i // ERROR "moved to heap: p$"
|
|
p2 := &p
|
|
param6(&p2)
|
|
}
|
|
|
|
// **in -> heap
|
|
func param7(i ***int) { // ERROR "leaking param content: i$"
|
|
sink = **i
|
|
}
|
|
|
|
func caller7() {
|
|
i := 0 // ERROR "moved to heap: i$"
|
|
p := &i
|
|
p2 := &p
|
|
param7(&p2)
|
|
}
|
|
|
|
// **in -> heap
|
|
func param8(i **int) { // ERROR "i does not escape$"
|
|
sink = **i // ERROR "\* \(\*i\) escapes to heap"
|
|
}
|
|
|
|
func caller8() {
|
|
i := 0
|
|
p := &i
|
|
param8(&p)
|
|
}
|
|
|
|
// *in -> out
|
|
func param9(p ***int) **int { // ERROR "leaking param: p to result ~r1 level=1"
|
|
return *p
|
|
}
|
|
|
|
func caller9a() {
|
|
i := 0
|
|
p := &i
|
|
p2 := &p
|
|
_ = param9(&p2)
|
|
}
|
|
|
|
func caller9b() {
|
|
i := 0 // ERROR "moved to heap: i$"
|
|
p := &i // ERROR "moved to heap: p$"
|
|
p2 := &p
|
|
sink = param9(&p2)
|
|
}
|
|
|
|
// **in -> out
|
|
func param10(p ***int) *int { // ERROR "leaking param: p to result ~r1 level=2"
|
|
return **p
|
|
}
|
|
|
|
func caller10a() {
|
|
i := 0
|
|
p := &i
|
|
p2 := &p
|
|
_ = param10(&p2)
|
|
}
|
|
|
|
func caller10b() {
|
|
i := 0 // ERROR "moved to heap: i$"
|
|
p := &i
|
|
p2 := &p
|
|
sink = param10(&p2)
|
|
}
|
|
|
|
// in escapes to heap (address of param taken and returned)
|
|
func param11(i **int) ***int { // ERROR "moved to heap: i$"
|
|
return &i
|
|
}
|
|
|
|
func caller11a() {
|
|
i := 0 // ERROR "moved to heap: i"
|
|
p := &i // ERROR "moved to heap: p"
|
|
_ = param11(&p)
|
|
}
|
|
|
|
func caller11b() {
|
|
i := 0 // ERROR "moved to heap: i$"
|
|
p := &i // ERROR "moved to heap: p$"
|
|
sink = param11(&p)
|
|
}
|
|
|
|
func caller11c() { // GOOD
|
|
i := 0 // ERROR "moved to heap: i$"
|
|
p := &i // ERROR "moved to heap: p"
|
|
sink = *param11(&p)
|
|
}
|
|
|
|
func caller11d() {
|
|
i := 0 // ERROR "moved to heap: i$"
|
|
p := &i // ERROR "moved to heap: p"
|
|
p2 := &p
|
|
sink = param11(p2)
|
|
}
|
|
|
|
// &in -> rcvr
|
|
type Indir struct {
|
|
p ***int
|
|
}
|
|
|
|
func (r *Indir) param12(i **int) { // ERROR "r does not escape$" "moved to heap: i$"
|
|
r.p = &i
|
|
}
|
|
|
|
func caller12a() {
|
|
i := 0 // ERROR "moved to heap: i$"
|
|
p := &i // ERROR "moved to heap: p$"
|
|
var r Indir
|
|
r.param12(&p)
|
|
_ = r
|
|
}
|
|
|
|
func caller12b() {
|
|
i := 0 // ERROR "moved to heap: i$"
|
|
p := &i // ERROR "moved to heap: p$"
|
|
r := &Indir{} // ERROR "&Indir literal does not escape$"
|
|
r.param12(&p)
|
|
_ = r
|
|
}
|
|
|
|
func caller12c() {
|
|
i := 0 // ERROR "moved to heap: i$"
|
|
p := &i // ERROR "moved to heap: p$"
|
|
r := Indir{}
|
|
r.param12(&p)
|
|
sink = r
|
|
}
|
|
|
|
func caller12d() {
|
|
i := 0 // ERROR "moved to heap: i$"
|
|
p := &i // ERROR "moved to heap: p$"
|
|
r := Indir{}
|
|
r.param12(&p)
|
|
sink = **r.p
|
|
}
|
|
|
|
// in -> value rcvr
|
|
type Val struct {
|
|
p **int
|
|
}
|
|
|
|
func (v Val) param13(i *int) { // ERROR "v does not escape$" "leaking param: i$"
|
|
*v.p = i
|
|
}
|
|
|
|
func caller13a() {
|
|
i := 0 // ERROR "moved to heap: i$"
|
|
var p *int
|
|
var v Val
|
|
v.p = &p
|
|
v.param13(&i)
|
|
_ = v
|
|
}
|
|
|
|
func caller13b() {
|
|
i := 0 // ERROR "moved to heap: i$"
|
|
var p *int
|
|
v := Val{&p}
|
|
v.param13(&i)
|
|
_ = v
|
|
}
|
|
|
|
func caller13c() {
|
|
i := 0 // ERROR "moved to heap: i$"
|
|
var p *int
|
|
v := &Val{&p} // ERROR "&Val literal does not escape$"
|
|
v.param13(&i)
|
|
_ = v
|
|
}
|
|
|
|
func caller13d() {
|
|
i := 0 // ERROR "moved to heap: i$"
|
|
var p *int // ERROR "moved to heap: p$"
|
|
var v Val
|
|
v.p = &p
|
|
v.param13(&i)
|
|
sink = v
|
|
}
|
|
|
|
func caller13e() {
|
|
i := 0 // ERROR "moved to heap: i$"
|
|
var p *int // ERROR "moved to heap: p$"
|
|
v := Val{&p}
|
|
v.param13(&i)
|
|
sink = v
|
|
}
|
|
|
|
func caller13f() {
|
|
i := 0 // ERROR "moved to heap: i$"
|
|
var p *int // ERROR "moved to heap: p$"
|
|
v := &Val{&p} // ERROR "&Val literal escapes to heap$"
|
|
v.param13(&i)
|
|
sink = v
|
|
}
|
|
|
|
func caller13g() {
|
|
i := 0 // ERROR "moved to heap: i$"
|
|
var p *int
|
|
v := Val{&p}
|
|
v.param13(&i)
|
|
sink = *v.p
|
|
}
|
|
|
|
func caller13h() {
|
|
i := 0 // ERROR "moved to heap: i$"
|
|
var p *int
|
|
v := &Val{&p} // ERROR "&Val literal does not escape$"
|
|
v.param13(&i)
|
|
sink = **v.p // ERROR "\* \(\*v\.p\) escapes to heap"
|
|
}
|
|
|
|
type Node struct {
|
|
p *Node
|
|
}
|
|
|
|
var Sink *Node
|
|
|
|
func f(x *Node) { // ERROR "leaking param content: x"
|
|
Sink = &Node{x.p} // ERROR "&Node literal escapes to heap"
|
|
}
|
|
|
|
func g(x *Node) *Node { // ERROR "leaking param content: x"
|
|
return &Node{x.p} // ERROR "&Node literal escapes to heap"
|
|
}
|
|
|
|
func h(x *Node) { // ERROR "leaking param: x"
|
|
y := &Node{x} // ERROR "&Node literal does not escape"
|
|
Sink = g(y)
|
|
f(y)
|
|
}
|
|
|
|
// interface(in) -> out
|
|
// See also issue 29353.
|
|
|
|
// Convert to a non-direct interface, require an allocation and
|
|
// copy x to heap (not to result).
|
|
func param14a(x [4]*int) interface{} { // ERROR "leaking param: x$"
|
|
return x // ERROR "x escapes to heap"
|
|
}
|
|
|
|
// Convert to a direct interface, does not need an allocation.
|
|
// So x only leaks to result.
|
|
func param14b(x *int) interface{} { // ERROR "leaking param: x to result ~r1 level=0"
|
|
return x
|
|
}
|