1 files changed, 200 insertions, 0 deletions
diff --git a/src/internal/types/testdata/check/cycles5.go b/src/internal/types/testdata/check/cycles5.go
new file mode 100644
index 0000000..5e0d191
--- /dev/null
+++ b/src/internal/types/testdata/check/cycles5.go
@@ -0,0 +1,200 @@
+// Copyright 2017 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 p
+
+import "unsafe"
+
+// test case from issue #18395
+
+type (
+	A interface { B }
+	B interface { C }
+	C interface { D; F() A }
+	D interface { G() B }
+)
+
+var _ = A(nil).G // G must be found
+
+
+// test case from issue #21804
+
+type sourceBridge interface {
+	listVersions() ([]Version, error)
+}
+
+type Constraint interface {
+	copyTo(*ConstraintMsg)
+}
+
+type ConstraintMsg struct{}
+
+func (m *ConstraintMsg) asUnpairedVersion() UnpairedVersion {
+	return nil
+}
+
+type Version interface {
+	Constraint
+}
+
+type UnpairedVersion interface {
+	Version
+}
+
+var _ Constraint = UnpairedVersion(nil)
+
+
+// derived test case from issue #21804
+
+type (
+	_ interface{ m(B1) }
+	A1 interface{ a(D1) }
+	B1 interface{ A1 }
+	C1 interface{ B1 }
+	D1 interface{ C1 }
+)
+
+var _ A1 = C1(nil)
+
+
+// derived test case from issue #22701
+
+func F(x I4) interface{} {
+	return x.Method()
+}
+
+type Unused interface {
+	RefersToI1(a I1)
+}
+
+type I1 interface {
+	I2
+	I3
+}
+
+type I2 interface {
+	RefersToI4() I4
+}
+
+type I3 interface {
+	Method() interface{}
+}
+
+type I4 interface {
+	I1
+}
+
+
+// check embedding of error interface
+
+type Error interface{ error }
+
+var err Error
+var _ = err.Error()
+
+
+// more esoteric cases
+
+type (
+	T1 interface { T2 }
+	T2 /* ERROR invalid recursive type */ T2
+)
+
+type (
+	T3 interface { T4 }
+	T4 /* ERROR invalid recursive type */ T5
+	T5 = T6
+	T6 = T7
+	T7 = T4
+)
+
+
+// arbitrary code may appear inside an interface
+
+const n = unsafe.Sizeof(func(){})
+
+type I interface {
+	m([unsafe.Sizeof(func() { I.m(nil, [n]byte{}) })]byte)
+}
+
+
+// test cases for varias alias cycles
+
+type T10 /* ERROR invalid recursive type */ = *T10                 // issue #25141
+type T11 /* ERROR invalid recursive type */ = interface{ f(T11) }  // issue #23139
+
+// issue #18640
+type (
+	aa = bb
+	bb struct {
+		*aa
+	}
+)
+
+type (
+	a struct{ *b }
+	b = c
+	c struct{ *b /* ERROR invalid use of type alias */ }
+)
+
+// issue #24939
+type (
+	_ interface {
+		M(P)
+	}
+
+	M interface {
+		F() P // ERROR invalid use of type alias
+	}
+
+	P = interface {
+		I() M
+	}
+)
+
+// issue #8699
+type T12 /* ERROR invalid recursive type */ [len(a12)]int
+var a12 = makeArray()
+func makeArray() (res T12) { return }
+
+// issue #20770
+var r /* ERROR invalid cycle in declaration of r */ = newReader()
+func newReader() r
+
+// variations of the theme of #8699 and #20770
+var arr /* ERROR cycle */ = f()
+func f() [len(arr)]int
+
+// issue #25790
+func ff(ff /* ERROR not a type */ )
+func gg((gg /* ERROR not a type */ ))
+
+type T13 /* ERROR invalid recursive type T13 */ [len(b13)]int
+var b13 T13
+
+func g1() [unsafe.Sizeof(g1)]int
+func g2() [unsafe.Sizeof(x2)]int
+var x2 = g2
+
+// verify that we get the correct sizes for the functions above
+// (note: assert is statically evaluated in go/types test mode)
+func init() {
+	assert(unsafe.Sizeof(g1) == 8)
+	assert(unsafe.Sizeof(x2) == 8)
+}
+
+func h() [h /* ERROR no value */ ()[0]]int { panic(0) }
+
+var c14 /* ERROR cycle */ T14
+type T14 [uintptr(unsafe.Sizeof(&c14))]byte
+
+// issue #34333
+type T15 /* ERROR invalid recursive type T15 */ struct {
+	f func() T16
+	b T16
+}
+
+type T16 struct {
+	T15
+}
+\ No newline at end of file