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

This reverts commit 5fd0ed7.

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 <[email protected]>
Reviewed-by: Eric Fang <[email protected]>

Author: zhangfannie

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

@@ -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() {
-			// When -d=checkptr=2 or -asan is enabled,
-			// treat conversions to unsafe.Pointer as an
+		if ir.ShouldCheckPtr(e.curfn, 2) && n.Type().IsUnsafePtr() && n.X.Type().IsPtr() {
+			// When -d=checkptr=2 is enabled, treat
+			// conversions to unsafe.Pointer as an
 			// escaping operation. This allows better
 			// runtime instrumentation, since we can more
 			// easily detect object boundaries on the heap

misc/cgo/testsanitizers/testdata/asan_unsafe_fail2.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 {