Revert "cmd/compile: set conversions to unsafe.Pointer as an escaping operation when -asan is enabled"

This reverts commit 5fd0ed7aaf.

Reason for revert: <The internal information in commit message is not removed.>

Change-Id: Id6845a9c8114ac71c56a1007a4d133a560a37fbc
Reviewed-on: https://go-review.googlesource.com/c/go/+/393314
Trust: Fannie Zhang <Fannie.Zhang@arm.com>
Reviewed-by: Eric Fang <eric.fang@arm.com>

misc/cgo/testsanitizers/asan_test.go

@@ -41,9 +41,6 @@ func TestASAN(t *testing.T) {
 		{src: "asan4_fail.go", memoryAccessError: "use-after-poison", errorLocation: "asan4_fail.go:13"},
 		{src: "asan5_fail.go", memoryAccessError: "use-after-poison", errorLocation: "asan5_fail.go:18"},
 		{src: "asan_useAfterReturn.go"},
-		{src: "asan_unsafe_fail1.go", memoryAccessError: "use-after-poison", errorLocation: "asan_unsafe_fail1.go:25"},
-		{src: "asan_unsafe_fail2.go", memoryAccessError: "use-after-poison", errorLocation: "asan_unsafe_fail2.go:25"},
-		{src: "asan_unsafe_fail3.go", memoryAccessError: "use-after-poison", errorLocation: "asan_unsafe_fail3.go:18"},
 	}
 	for _, tc := range cases {
 		tc := tc

misc/cgo/testsanitizers/testdata/asan_unsafe_fail1.go

@@ -1,27 +0,0 @@
-// Copyright 2022 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
-
-import (
-	"fmt"
-	"unsafe"
-)
-
-func main() {
-	a := 1
-	b := 2
-	c := add(a, b)
-	d := a + b
-	fmt.Println(c, d)
-}
-
-//go:noinline
-func add(a1, b1 int) int {
-	// The arguments.
-	// When -asan is enabled, unsafe.Pointer(&a1) conversion is escaping.
-	var p *int = (*int)(unsafe.Pointer(uintptr(unsafe.Pointer(&a1)) + 1*unsafe.Sizeof(int(1))))
-	*p = 10 // BOOM
-	return a1 + b1
-}

misc/cgo/testsanitizers/testdata/asan_unsafe_fail2.go

@@ -1,28 +0,0 @@
-// Copyright 2022 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
-
-import (
-	"fmt"
-	"unsafe"
-)
-
-func main() {
-	a := 1
-	b := 2
-	c := add(a, b)
-	d := a + b
-	fmt.Println(c, d)
-}
-
-//go:noinline
-func add(a1, b1 int) (ret int) {
-	// The return value
-	// When -asan is enabled, the unsafe.Pointer(&ret) conversion is escaping.
-	var p *int = (*int)(unsafe.Pointer(uintptr(unsafe.Pointer(&ret)) + 1*unsafe.Sizeof(int(1))))
-	*p = 123 // BOOM
-	ret = a1 + b1
-	return
-}

misc/cgo/testsanitizers/testdata/asan_unsafe_fail3.go

@@ -1,21 +0,0 @@
-// Copyright 2022 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
-
-import (
-	"fmt"
-	"unsafe"
-)
-
-func main() {
-	a := 1
-	b := 2
-	// The local variables.
-	// When -asan is enabled, the unsafe.Pointer(&a) conversion is escaping.
-	var p *int = (*int)(unsafe.Pointer(uintptr(unsafe.Pointer(&a)) + 1*unsafe.Sizeof(int(1))))
-	*p = 20 // BOOM
-	d := a + b
-	fmt.Println(d)
-}

src/cmd/compile/internal/escape/expr.go

@@ -100,9 +100,9 @@ func (e *escape) exprSkipInit(k hole, n ir.Node) {
 
 	case ir.OCONV, ir.OCONVNOP:
 		n := n.(*ir.ConvExpr)
-		if (ir.ShouldCheckPtr(e.curfn, 2) || ir.ShouldAsanCheckPtr(e.curfn)) && n.Type().IsUnsafePtr() && n.X.Type().IsPtr() {
+		if ir.ShouldCheckPtr(e.curfn, 2) && n.Type().IsUnsafePtr() && n.X.Type().IsPtr() {
-			// When -d=checkptr=2 or -asan is enabled,
+			// When -d=checkptr=2 is enabled, treat
-			// treat conversions to unsafe.Pointer as an
+			// conversions to unsafe.Pointer as an
 			// escaping operation. This allows better
 			// runtime instrumentation, since we can more
 			// easily detect object boundaries on the heap

src/cmd/compile/internal/ir/expr.go

@@ -1036,12 +1036,6 @@ func ShouldCheckPtr(fn *Func, level int) bool {
 	return base.Debug.Checkptr >= level && fn.Pragma&NoCheckPtr == 0
 }
 
-// ShouldAsanCheckPtr reports whether pointer checking should be enabled for
-// function fn when -asan is enabled.
-func ShouldAsanCheckPtr(fn *Func) bool {
-	return base.Flag.ASan && fn.Pragma&NoCheckPtr == 0
-}
-
 // IsReflectHeaderDataField reports whether l is an expression p.Data
 // where p has type reflect.SliceHeader or reflect.StringHeader.
 func IsReflectHeaderDataField(l Node) bool {