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cmd/compile/internal/gc: unify self-assignment checks in esc.go

Move slice self-assign check into isSelfAssign function.
Make debug output consistent for all self-assignment cases.

Change-Id: I0e4cc7b3c1fcaeace7226dd80a0dc1ea97347a55
Reviewed-on: https://go-review.googlesource.com/136276
Run-TryBot: Iskander Sharipov <iskander.sharipov@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
This commit is contained in:
Iskander Sharipov 2018-09-19 15:53:03 +03:00
parent 9a033bf9d3
commit 499fbb1a8a
3 changed files with 24 additions and 27 deletions

View File

@ -705,6 +705,10 @@ func (e *EscState) isSliceSelfAssign(dst, src *Node) bool {
// isSelfAssign reports whether assignment from src to dst can
// be ignored by the escape analysis as it's effectively a self-assignment.
func (e *EscState) isSelfAssign(dst, src *Node) bool {
if e.isSliceSelfAssign(dst, src) {
return true
}
// Detect trivial assignments that assign back to the same object.
//
// It covers these cases:
@ -890,13 +894,6 @@ opSwitch:
case OAS, OASOP:
// Filter out some no-op assignments for escape analysis.
if e.isSliceSelfAssign(n.Left, n.Right) {
if Debug['m'] != 0 {
Warnl(n.Pos, "%v ignoring self-assignment to %S", e.curfnSym(n), n.Left)
}
break
}
if e.isSelfAssign(n.Left, n.Right) {
if Debug['m'] != 0 {
Warnl(n.Pos, "%v ignoring self-assignment in %S", e.curfnSym(n), n)

View File

@ -1602,10 +1602,10 @@ type Buffer struct {
}
func (b *Buffer) foo() { // ERROR "\(\*Buffer\).foo b does not escape$"
b.buf1 = b.buf1[1:2] // ERROR "\(\*Buffer\).foo ignoring self-assignment to b.buf1$"
b.buf1 = b.buf1[1:2:3] // ERROR "\(\*Buffer\).foo ignoring self-assignment to b.buf1$"
b.buf1 = b.buf2[1:2] // ERROR "\(\*Buffer\).foo ignoring self-assignment to b.buf1$"
b.buf1 = b.buf2[1:2:3] // ERROR "\(\*Buffer\).foo ignoring self-assignment to b.buf1$"
b.buf1 = b.buf1[1:2] // ERROR "\(\*Buffer\).foo ignoring self-assignment in b.buf1 = b.buf1\[1:2\]$"
b.buf1 = b.buf1[1:2:3] // ERROR "\(\*Buffer\).foo ignoring self-assignment in b.buf1 = b.buf1\[1:2:3\]$"
b.buf1 = b.buf2[1:2] // ERROR "\(\*Buffer\).foo ignoring self-assignment in b.buf1 = b.buf2\[1:2\]$"
b.buf1 = b.buf2[1:2:3] // ERROR "\(\*Buffer\).foo ignoring self-assignment in b.buf1 = b.buf2\[1:2:3\]$"
}
func (b *Buffer) bar() { // ERROR "leaking param: b$"
@ -1613,13 +1613,13 @@ func (b *Buffer) bar() { // ERROR "leaking param: b$"
}
func (b *Buffer) arrayPtr() { // ERROR "\(\*Buffer\).arrayPtr b does not escape"
b.buf1 = b.arrPtr[1:2] // ERROR "\(\*Buffer\).arrayPtr ignoring self-assignment to b.buf1"
b.buf1 = b.arrPtr[1:2:3] // ERROR "\(\*Buffer\).arrayPtr ignoring self-assignment to b.buf1"
b.buf1 = b.arrPtr[1:2] // ERROR "\(\*Buffer\).arrayPtr ignoring self-assignment in b.buf1 = b.arrPtr\[1:2\]$"
b.buf1 = b.arrPtr[1:2:3] // ERROR "\(\*Buffer\).arrayPtr ignoring self-assignment in b.buf1 = b.arrPtr\[1:2:3\]$"
}
func (b *Buffer) baz() { // ERROR "\(\*Buffer\).baz b does not escape$"
b.str1 = b.str1[1:2] // ERROR "\(\*Buffer\).baz ignoring self-assignment to b.str1$"
b.str1 = b.str2[1:2] // ERROR "\(\*Buffer\).baz ignoring self-assignment to b.str1$"
b.str1 = b.str1[1:2] // ERROR "\(\*Buffer\).baz ignoring self-assignment in b.str1 = b.str1\[1:2\]$"
b.str1 = b.str2[1:2] // ERROR "\(\*Buffer\).baz ignoring self-assignment in b.str1 = b.str2\[1:2\]$"
}
func (b *Buffer) bat() { // ERROR "leaking param content: b$"
@ -1629,8 +1629,8 @@ func (b *Buffer) bat() { // ERROR "leaking param content: b$"
}
func quux(sp *string, bp *[]byte) { // ERROR "quux bp does not escape$" "quux sp does not escape$"
*sp = (*sp)[1:2] // ERROR "quux ignoring self-assignment to \*sp$"
*bp = (*bp)[1:2] // ERROR "quux ignoring self-assignment to \*bp$"
*sp = (*sp)[1:2] // ERROR "quux ignoring self-assignment in \*sp = \(\*sp\)\[1:2\]$"
*bp = (*bp)[1:2] // ERROR "quux ignoring self-assignment in \*bp = \(\*bp\)\[1:2\]$"
}
type StructWithString struct {

View File

@ -1602,10 +1602,10 @@ type Buffer struct {
}
func (b *Buffer) foo() { // ERROR "\(\*Buffer\).foo b does not escape$"
b.buf1 = b.buf1[1:2] // ERROR "\(\*Buffer\).foo ignoring self-assignment to b.buf1$"
b.buf1 = b.buf1[1:2:3] // ERROR "\(\*Buffer\).foo ignoring self-assignment to b.buf1$"
b.buf1 = b.buf2[1:2] // ERROR "\(\*Buffer\).foo ignoring self-assignment to b.buf1$"
b.buf1 = b.buf2[1:2:3] // ERROR "\(\*Buffer\).foo ignoring self-assignment to b.buf1$"
b.buf1 = b.buf1[1:2] // ERROR "\(\*Buffer\).foo ignoring self-assignment in b.buf1 = b.buf1\[1:2\]$"
b.buf1 = b.buf1[1:2:3] // ERROR "\(\*Buffer\).foo ignoring self-assignment in b.buf1 = b.buf1\[1:2:3\]$"
b.buf1 = b.buf2[1:2] // ERROR "\(\*Buffer\).foo ignoring self-assignment in b.buf1 = b.buf2\[1:2\]$"
b.buf1 = b.buf2[1:2:3] // ERROR "\(\*Buffer\).foo ignoring self-assignment in b.buf1 = b.buf2\[1:2:3\]$"
}
func (b *Buffer) bar() { // ERROR "leaking param: b$"
@ -1613,13 +1613,13 @@ func (b *Buffer) bar() { // ERROR "leaking param: b$"
}
func (b *Buffer) arrayPtr() { // ERROR "\(\*Buffer\).arrayPtr b does not escape"
b.buf1 = b.arrPtr[1:2] // ERROR "\(\*Buffer\).arrayPtr ignoring self-assignment to b.buf1"
b.buf1 = b.arrPtr[1:2:3] // ERROR "\(\*Buffer\).arrayPtr ignoring self-assignment to b.buf1"
b.buf1 = b.arrPtr[1:2] // ERROR "\(\*Buffer\).arrayPtr ignoring self-assignment in b.buf1 = b.arrPtr\[1:2\]$"
b.buf1 = b.arrPtr[1:2:3] // ERROR "\(\*Buffer\).arrayPtr ignoring self-assignment in b.buf1 = b.arrPtr\[1:2:3\]$"
}
func (b *Buffer) baz() { // ERROR "\(\*Buffer\).baz b does not escape$"
b.str1 = b.str1[1:2] // ERROR "\(\*Buffer\).baz ignoring self-assignment to b.str1$"
b.str1 = b.str2[1:2] // ERROR "\(\*Buffer\).baz ignoring self-assignment to b.str1$"
b.str1 = b.str1[1:2] // ERROR "\(\*Buffer\).baz ignoring self-assignment in b.str1 = b.str1\[1:2\]$"
b.str1 = b.str2[1:2] // ERROR "\(\*Buffer\).baz ignoring self-assignment in b.str1 = b.str2\[1:2\]$"
}
func (b *Buffer) bat() { // ERROR "leaking param content: b$"
@ -1629,8 +1629,8 @@ func (b *Buffer) bat() { // ERROR "leaking param content: b$"
}
func quux(sp *string, bp *[]byte) { // ERROR "quux bp does not escape$" "quux sp does not escape$"
*sp = (*sp)[1:2] // ERROR "quux ignoring self-assignment to \*sp$"
*bp = (*bp)[1:2] // ERROR "quux ignoring self-assignment to \*bp$"
*sp = (*sp)[1:2] // ERROR "quux ignoring self-assignment in \*sp = \(\*sp\)\[1:2\]$"
*bp = (*bp)[1:2] // ERROR "quux ignoring self-assignment in \*bp = \(\*bp\)\[1:2\]$"
}
type StructWithString struct {