cmd/compile: fix load of interface{}-typed OpIData in expand_calls
In certain cases, the declkared type of an OpIData is interface{}.
This was not expected (since interface{} is a pair, right?) and
thus caused a crash. What is intended is that these be treated as
a byteptr, so do that instead (this is what happens in 1.15).
Fixes #42568.
Change-Id: Id7c9e5dc2cbb5d7c71c6748832491ea62b0b339f
Reviewed-on: https://go-review.googlesource.com/c/go/+/270057
Trust: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
diff --git a/src/cmd/compile/internal/amd64/ssa.go b/src/cmd/compile/internal/amd64/ssa.go
index 76e33a3..5ff05a0 100644
--- a/src/cmd/compile/internal/amd64/ssa.go
+++ b/src/cmd/compile/internal/amd64/ssa.go
@@ -76,7 +76,7 @@
return x86.AMOVQ
}
}
- panic("bad store type")
+ panic(fmt.Sprintf("bad store type %v", t))
}
// moveByType returns the reg->reg move instruction of the given type.
@@ -101,7 +101,7 @@
case 16:
return x86.AMOVUPS // int128s are in SSE registers
default:
- panic(fmt.Sprintf("bad int register width %d:%s", t.Size(), t))
+ panic(fmt.Sprintf("bad int register width %d:%v", t.Size(), t))
}
}
}
diff --git a/src/cmd/compile/internal/ssa/expand_calls.go b/src/cmd/compile/internal/ssa/expand_calls.go
index fbde19d..3681af6 100644
--- a/src/cmd/compile/internal/ssa/expand_calls.go
+++ b/src/cmd/compile/internal/ssa/expand_calls.go
@@ -196,6 +196,9 @@
}
if leaf.Op == OpIData {
leafType = removeTrivialWrapperTypes(leaf.Type)
+ if leafType.IsEmptyInterface() {
+ leafType = typ.BytePtr
+ }
}
aux := selector.Aux
auxInt := selector.AuxInt + offset
diff --git a/test/fixedbugs/issue42568.go b/test/fixedbugs/issue42568.go
new file mode 100644
index 0000000..834fdc5
--- /dev/null
+++ b/test/fixedbugs/issue42568.go
@@ -0,0 +1,25 @@
+// compile
+
+// Copyright 2020 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.
+
+// Ensure that late expansion correctly handles an OpIData with type interface{}
+
+package p
+
+type S struct{}
+
+func (S) M() {}
+
+type I interface {
+ M()
+}
+
+func f(i I) {
+ o := i.(interface{})
+ if _, ok := i.(*S); ok {
+ o = nil
+ }
+ println(o)
+}
