1 files changed, 587 insertions, 0 deletions
diff --git a/test/recover.go b/test/recover.go
new file mode 100644
index 0000000..e4187c0
--- /dev/null
+++ b/test/recover.go
@@ -0,0 +1,587 @@
+// run
+
+// Copyright 2010 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.
+
+// Test of basic recover functionality.
+
+package main
+
+import (
+	"os"
+	"reflect"
+	"runtime"
+)
+
+func main() {
+	// go.tools/ssa/interp still has:
+	// - some lesser bugs in recover()
+	// - incomplete support for reflection
+	interp := os.Getenv("GOSSAINTERP") != ""
+
+	test1()
+	test1WithClosures()
+	test2()
+	test3()
+	if !interp {
+		test4()
+	}
+	test5()
+	test6()
+	test6WithClosures()
+	test7()
+	test8()
+	test9()
+	if !interp {
+		test9reflect1()
+		test9reflect2()
+	}
+	test10()
+	if !interp {
+		test10reflect1()
+		test10reflect2()
+	}
+	test11()
+	if !interp {
+		test11reflect1()
+		test11reflect2()
+	}
+	test111()
+	test12()
+	if !interp {
+		test12reflect1()
+		test12reflect2()
+	}
+	test13()
+	if !interp {
+		test13reflect1()
+		test13reflect2()
+	}
+	test14()
+	if !interp {
+		test14reflect1()
+		test14reflect2()
+		test15()
+		test16()
+	}
+}
+
+func die() {
+	runtime.Breakpoint() // can't depend on panic
+}
+
+func mustRecoverBody(v1, v2, v3, x interface{}) {
+	v := v1
+	if v != nil {
+		println("spurious recover", v)
+		die()
+	}
+	v = v2
+	if v == nil {
+		println("missing recover", x.(int))
+		die() // panic is useless here
+	}
+	if v != x {
+		println("wrong value", v, x)
+		die()
+	}
+
+	// the value should be gone now regardless
+	v = v3
+	if v != nil {
+		println("recover didn't recover")
+		die()
+	}
+}
+
+func doubleRecover() interface{} {
+	return recover()
+}
+
+func mustRecover(x interface{}) {
+	mustRecoverBody(doubleRecover(), recover(), recover(), x)
+}
+
+func mustNotRecover() {
+	v := recover()
+	if v != nil {
+		println("spurious recover", v)
+		die()
+	}
+}
+
+func withoutRecover() {
+	mustNotRecover() // because it's a sub-call
+}
+
+func withoutRecoverRecursive(n int) {
+	if n == 0 {
+		withoutRecoverRecursive(1)
+	} else {
+		v := recover()
+		if v != nil {
+			println("spurious recover (recursive)", v)
+			die()
+		}
+	}
+}
+
+func test1() {
+	defer mustNotRecover()           // because mustRecover will squelch it
+	defer mustRecover(1)             // because of panic below
+	defer withoutRecover()           // should be no-op, leaving for mustRecover to find
+	defer withoutRecoverRecursive(0) // ditto
+	panic(1)
+}
+
+// Repeat test1 with closures instead of standard function.
+// Interesting because recover bases its decision
+// on the frame pointer of its caller, and a closure's
+// frame pointer is in the middle of its actual arguments
+// (after the hidden ones for the closed-over variables).
+func test1WithClosures() {
+	defer func() {
+		v := recover()
+		if v != nil {
+			println("spurious recover in closure")
+			die()
+		}
+	}()
+	defer func(x interface{}) {
+		mustNotRecover()
+		v := recover()
+		if v == nil {
+			println("missing recover", x.(int))
+			die()
+		}
+		if v != x {
+			println("wrong value", v, x)
+			die()
+		}
+	}(1)
+	defer func() {
+		mustNotRecover()
+	}()
+	panic(1)
+}
+
+func test2() {
+	// Recover only sees the panic argument
+	// if it is called from a deferred call.
+	// It does not see the panic when called from a call within a deferred call (too late)
+	// nor does it see the panic when it *is* the deferred call (too early).
+	defer mustRecover(2)
+	defer recover() // should be no-op
+	panic(2)
+}
+
+func test3() {
+	defer mustNotRecover()
+	defer func() {
+		recover() // should squelch
+	}()
+	panic(3)
+}
+
+func test4() {
+	// Equivalent to test3 but using defer to make the call.
+	defer mustNotRecover()
+	defer func() {
+		defer recover() // should squelch
+	}()
+	panic(4)
+}
+
+// Check that closures can set output arguments.
+// Run g().  If it panics, return x; else return deflt.
+func try(g func(), deflt interface{}) (x interface{}) {
+	defer func() {
+		if v := recover(); v != nil {
+			x = v
+		}
+	}()
+	defer g()
+	return deflt
+}
+
+// Check that closures can set output arguments.
+// Run g().  If it panics, return x; else return deflt.
+func try1(g func(), deflt interface{}) (x interface{}) {
+	defer func() {
+		if v := recover(); v != nil {
+			x = v
+		}
+	}()
+	defer g()
+	x = deflt
+	return
+}
+
+func test5() {
+	v := try(func() { panic(5) }, 55).(int)
+	if v != 5 {
+		println("wrong value", v, 5)
+		die()
+	}
+
+	s := try(func() {}, "hi").(string)
+	if s != "hi" {
+		println("wrong value", s, "hi")
+		die()
+	}
+
+	v = try1(func() { panic(5) }, 55).(int)
+	if v != 5 {
+		println("try1 wrong value", v, 5)
+		die()
+	}
+
+	s = try1(func() {}, "hi").(string)
+	if s != "hi" {
+		println("try1 wrong value", s, "hi")
+		die()
+	}
+}
+
+// When a deferred big call starts, it must first
+// create yet another stack segment to hold the
+// giant frame for x.  Make sure that doesn't
+// confuse recover.
+func big(mustRecover bool) {
+	var x [100000]int
+	x[0] = 1
+	x[99999] = 1
+	_ = x
+
+	v := recover()
+	if mustRecover {
+		if v == nil {
+			println("missing big recover")
+			die()
+		}
+	} else {
+		if v != nil {
+			println("spurious big recover")
+			die()
+		}
+	}
+}
+
+func test6() {
+	defer big(false)
+	defer big(true)
+	panic(6)
+}
+
+func test6WithClosures() {
+	defer func() {
+		var x [100000]int
+		x[0] = 1
+		x[99999] = 1
+		_ = x
+		if recover() != nil {
+			println("spurious big closure recover")
+			die()
+		}
+	}()
+	defer func() {
+		var x [100000]int
+		x[0] = 1
+		x[99999] = 1
+		_ = x
+		if recover() == nil {
+			println("missing big closure recover")
+			die()
+		}
+	}()
+	panic("6WithClosures")
+}
+
+func test7() {
+	ok := false
+	func() {
+		// should panic, then call mustRecover 7, which stops the panic.
+		// then should keep processing ordinary defers earlier than that one
+		// before returning.
+		// this test checks that the defer func on the next line actually runs.
+		defer func() { ok = true }()
+		defer mustRecover(7)
+		panic(7)
+	}()
+	if !ok {
+		println("did not run ok func")
+		die()
+	}
+}
+
+func varargs(s *int, a ...int) {
+	*s = 0
+	for _, v := range a {
+		*s += v
+	}
+	if recover() != nil {
+		*s += 100
+	}
+}
+
+func test8a() (r int) {
+	defer varargs(&r, 1, 2, 3)
+	panic(0)
+}
+
+func test8b() (r int) {
+	defer varargs(&r, 4, 5, 6)
+	return
+}
+
+func test8() {
+	if test8a() != 106 || test8b() != 15 {
+		println("wrong value")
+		die()
+	}
+}
+
+type I interface {
+	M()
+}
+
+// pointer receiver, so no wrapper in i.M()
+type T1 struct{}
+
+func (*T1) M() {
+	mustRecoverBody(doubleRecover(), recover(), recover(), 9)
+}
+
+func test9() {
+	var i I = &T1{}
+	defer i.M()
+	panic(9)
+}
+
+func test9reflect1() {
+	f := reflect.ValueOf(&T1{}).Method(0).Interface().(func())
+	defer f()
+	panic(9)
+}
+
+func test9reflect2() {
+	f := reflect.TypeOf(&T1{}).Method(0).Func.Interface().(func(*T1))
+	defer f(&T1{})
+	panic(9)
+}
+
+// word-sized value receiver, so no wrapper in i.M()
+type T2 uintptr
+
+func (T2) M() {
+	mustRecoverBody(doubleRecover(), recover(), recover(), 10)
+}
+
+func test10() {
+	var i I = T2(0)
+	defer i.M()
+	panic(10)
+}
+
+func test10reflect1() {
+	f := reflect.ValueOf(T2(0)).Method(0).Interface().(func())
+	defer f()
+	panic(10)
+}
+
+func test10reflect2() {
+	f := reflect.TypeOf(T2(0)).Method(0).Func.Interface().(func(T2))
+	defer f(T2(0))
+	panic(10)
+}
+
+// tiny receiver, so basic wrapper in i.M()
+type T3 struct{}
+
+func (T3) M() {
+	mustRecoverBody(doubleRecover(), recover(), recover(), 11)
+}
+
+func test11() {
+	var i I = T3{}
+	defer i.M()
+	panic(11)
+}
+
+func test11reflect1() {
+	f := reflect.ValueOf(T3{}).Method(0).Interface().(func())
+	defer f()
+	panic(11)
+}
+
+func test11reflect2() {
+	f := reflect.TypeOf(T3{}).Method(0).Func.Interface().(func(T3))
+	defer f(T3{})
+	panic(11)
+}
+
+// tiny receiver, so basic wrapper in i.M()
+type T3deeper struct{}
+
+func (T3deeper) M() {
+	badstate() // difference from T3
+	mustRecoverBody(doubleRecover(), recover(), recover(), 111)
+}
+
+func test111() {
+	var i I = T3deeper{}
+	defer i.M()
+	panic(111)
+}
+
+type Tiny struct{}
+
+func (Tiny) M() {
+	panic(112)
+}
+
+// i.M is a wrapper, and i.M panics.
+//
+// This is a torture test for an old implementation of recover that
+// tried to deal with wrapper functions by doing some argument
+// positioning math on both entry and exit. Doing anything on exit
+// is a problem because sometimes functions exit via panic instead
+// of an ordinary return, so panic would have to know to do the
+// same math when unwinding the stack. It gets complicated fast.
+// This particular test never worked with the old scheme, because
+// panic never did the right unwinding math.
+//
+// The new scheme adjusts Panic.argp on entry to a wrapper.
+// It has no exit work, so if a wrapper is interrupted by a panic,
+// there's no cleanup that panic itself must do.
+// This test just works now.
+func badstate() {
+	defer func() {
+		recover()
+	}()
+	var i I = Tiny{}
+	i.M()
+}
+
+// large receiver, so basic wrapper in i.M()
+type T4 [2]string
+
+func (T4) M() {
+	mustRecoverBody(doubleRecover(), recover(), recover(), 12)
+}
+
+func test12() {
+	var i I = T4{}
+	defer i.M()
+	panic(12)
+}
+
+func test12reflect1() {
+	f := reflect.ValueOf(T4{}).Method(0).Interface().(func())
+	defer f()
+	panic(12)
+}
+
+func test12reflect2() {
+	f := reflect.TypeOf(T4{}).Method(0).Func.Interface().(func(T4))
+	defer f(T4{})
+	panic(12)
+}
+
+// enormous receiver, so wrapper splits stack to call M
+type T5 [8192]byte
+
+func (T5) M() {
+	mustRecoverBody(doubleRecover(), recover(), recover(), 13)
+}
+
+func test13() {
+	var i I = T5{}
+	defer i.M()
+	panic(13)
+}
+
+func test13reflect1() {
+	f := reflect.ValueOf(T5{}).Method(0).Interface().(func())
+	defer f()
+	panic(13)
+}
+
+func test13reflect2() {
+	f := reflect.TypeOf(T5{}).Method(0).Func.Interface().(func(T5))
+	defer f(T5{})
+	panic(13)
+}
+
+// enormous receiver + enormous method frame, so wrapper splits stack to call M,
+// and then M splits stack to allocate its frame.
+// recover must look back two frames to find the panic.
+type T6 [8192]byte
+
+var global byte
+
+func (T6) M() {
+	var x [8192]byte
+	x[0] = 1
+	x[1] = 2
+	for i := range x {
+		global += x[i]
+	}
+	mustRecoverBody(doubleRecover(), recover(), recover(), 14)
+}
+
+func test14() {
+	var i I = T6{}
+	defer i.M()
+	panic(14)
+}
+
+func test14reflect1() {
+	f := reflect.ValueOf(T6{}).Method(0).Interface().(func())
+	defer f()
+	panic(14)
+}
+
+func test14reflect2() {
+	f := reflect.TypeOf(T6{}).Method(0).Func.Interface().(func(T6))
+	defer f(T6{})
+	panic(14)
+}
+
+// function created by reflect.MakeFunc
+
+func reflectFunc(args []reflect.Value) (results []reflect.Value) {
+	mustRecoverBody(doubleRecover(), recover(), recover(), 15)
+	return nil
+}
+
+func test15() {
+	f := reflect.MakeFunc(reflect.TypeOf((func())(nil)), reflectFunc).Interface().(func())
+	defer f()
+	panic(15)
+}
+
+func reflectFunc2(args []reflect.Value) (results []reflect.Value) {
+	// This will call reflectFunc3
+	args[0].Interface().(func())()
+	return nil
+}
+
+func reflectFunc3(args []reflect.Value) (results []reflect.Value) {
+	if v := recover(); v != nil {
+		println("spurious recover", v)
+		die()
+	}
+	return nil
+}
+
+func test16() {
+	defer mustRecover(16)
+
+	f2 := reflect.MakeFunc(reflect.TypeOf((func(func()))(nil)), reflectFunc2).Interface().(func(func()))
+	f3 := reflect.MakeFunc(reflect.TypeOf((func())(nil)), reflectFunc3).Interface().(func())
+	defer f2(f3)
+
+	panic(16)
+}