go.tools/go/ssa/interp: some fixes to tests

- Break out parts of coverage.go into more specific files.
- Re-enable test of nil interface-to-interface conversion.
- Update initorder test to reflect spec ambiguity and gc vs go/types variance.
- Re-enable test dependent on now-fixed bug 8189 ("value,ok" yields an untyped bool)

LGTM=gri
R=gri
CC=golang-codereviews
https://golang.org/cl/119530043

go/ssa/interp/interp_test.go

@@ -135,14 +135,18 @@ var gorootTestTests = []string{
 // These are files in go.tools/go/ssa/interp/testdata/.
 var testdataTests = []string{
 	"boundmeth.go",
+	"complit.go",
 	"coverage.go",
+	"defer.go",
 	"fieldprom.go",
 	"ifaceconv.go",
 	"ifaceprom.go",
 	"initorder.go",
 	"methprom.go",
 	"mrvchain.go",
+	"range.go",
 	"recover.go",
+	"static.go",
 	"callstack.go",
 }
 

go/ssa/interp/testdata/complit.go

@@ -0,0 +1,84 @@
+package main
+
+// Tests of composite literals.
+
+import "fmt"
+
+// Map literals.
+func init() {
+	type M map[int]int
+	m1 := []*M{{1: 1}, &M{2: 2}}
+	want := "map[1:1] map[2:2]"
+	if got := fmt.Sprint(*m1[0], *m1[1]); got != want {
+		panic(got)
+	}
+	m2 := []M{{1: 1}, M{2: 2}}
+	if got := fmt.Sprint(m2[0], m2[1]); got != want {
+		panic(got)
+	}
+}
+
+// Nonliteral keys in composite literal.
+func init() {
+	const zero int = 1
+	var v = []int{1 + zero: 42}
+	if x := fmt.Sprint(v); x != "[0 0 42]" {
+		panic(x)
+	}
+}
+
+// Test for in-place initialization.
+func init() {
+	// struct
+	type S struct {
+		a, b int
+	}
+	s := S{1, 2}
+	s = S{b: 3}
+	if s.a != 0 {
+		panic("s.a != 0")
+	}
+	if s.b != 3 {
+		panic("s.b != 3")
+	}
+	s = S{}
+	if s.a != 0 {
+		panic("s.a != 0")
+	}
+	if s.b != 0 {
+		panic("s.b != 0")
+	}
+
+	// array
+	type A [4]int
+	a := A{2, 4, 6, 8}
+	a = A{1: 6, 2: 4}
+	if a[0] != 0 {
+		panic("a[0] != 0")
+	}
+	if a[1] != 6 {
+		panic("a[1] != 6")
+	}
+	if a[2] != 4 {
+		panic("a[2] != 4")
+	}
+	if a[3] != 0 {
+		panic("a[3] != 0")
+	}
+	a = A{}
+	if a[0] != 0 {
+		panic("a[0] != 0")
+	}
+	if a[1] != 0 {
+		panic("a[1] != 0")
+	}
+	if a[2] != 0 {
+		panic("a[2] != 0")
+	}
+	if a[3] != 0 {
+		panic("a[3] != 0")
+	}
+}
+
+func main() {
+}

go/ssa/interp/testdata/coverage.go

@@ -1,11 +1,8 @@
 // This interpreter test is designed to run very quickly yet provide
 // some coverage of a broad selection of constructs.
-// TODO(adonovan): more.
 //
 // Validate this file with 'go run' after editing.
 // TODO(adonovan): break this into small files organized by theme.
-// TODO(adonovan): move static tests (sanity checks) of ssa
-// construction into ssa/testdata.
 
 package main
 
@@ -14,17 +11,6 @@ import (
 	"reflect"
 )
 
-const zero int = 1
-
-var v = []int{1 + zero: 42}
-
-// Nonliteral keys in composite literal.
-func init() {
-	if x := fmt.Sprint(v); x != "[0 0 42]" {
-		panic(x)
-	}
-}
-
 func init() {
 	// Call of variadic function with (implicit) empty slice.
 	if x := fmt.Sprint(); x != "" {
@@ -126,40 +112,6 @@ func init() {
 	}
 }
 
-// Range over string.
-func init() {
-	if x := len("Hello, 世界"); x != 13 { // bytes
-		panic(x)
-	}
-	var indices []int
-	var runes []rune
-	for i, r := range "Hello, 世界" {
-		runes = append(runes, r)
-		indices = append(indices, i)
-	}
-	if x := fmt.Sprint(runes); x != "[72 101 108 108 111 44 32 19990 30028]" {
-		panic(x)
-	}
-	if x := fmt.Sprint(indices); x != "[0 1 2 3 4 5 6 7 10]" {
-		panic(x)
-	}
-	s := ""
-	for _, r := range runes {
-		s = fmt.Sprintf("%s%c", s, r)
-	}
-	if s != "Hello, 世界" {
-		panic(s)
-	}
-
-	var x int
-	for range "Hello, 世界" {
-		x++
-	}
-	if x != len(indices) {
-		panic(x)
-	}
-}
-
 func main() {
 	print() // legal
 
@@ -289,25 +241,6 @@ func main() {
 	_ = map[int]*struct{}{0: {}}
 }
 
-// A blocking select (sans "default:") cannot fall through.
-// Regression test for issue 7022.
-func bug7022() int {
-	var c1, c2 chan int
-	select {
-	case <-c1:
-		return 123
-	case <-c2:
-		return 456
-	}
-}
-
-// Parens should not prevent intrinsic treatment of built-ins.
-// (Regression test for a crash.)
-func init() {
-	_ = (new)(int)
-	_ = (make)([]int, 0)
-}
-
 type mybool bool
 
 func (mybool) f() {}
@@ -350,26 +283,6 @@ func init() {
 	}
 }
 
-var order []int
-
-func create(x int) int {
-	order = append(order, x)
-	return x
-}
-
-var c = create(b + 1)
-var a, b = create(1), create(2)
-
-// Initialization order of package-level value specs.
-func init() {
-	if x := fmt.Sprint(order); x != "[1 2 3]" {
-		panic(x)
-	}
-	if c != 3 {
-		panic(c)
-	}
-}
-
 // Shifts.
 func init() {
 	var i int64 = 1
@@ -408,15 +321,16 @@ func init() {
 
 // An I->I type-assert fails iff the value is nil.
 func init() {
-	// TODO(adonovan): temporarily disabled; see comment at bottom of file.
+	defer func() {
-	// defer func() {
+		r := fmt.Sprint(recover())
-	// 	r := fmt.Sprint(recover())
+		// Exact error varies by toolchain.
-	// 	if r != "interface conversion: interface is nil, not main.I" {
+		if r != "runtime error: interface conversion: interface is nil, not main.I" &&
-	// 		panic("I->I type assertion succeeded for nil value")
+			r != "interface conversion: interface is nil, not main.I" {
-	// 	}
+			panic("I->I type assertion succeeded for nil value")
-	// }()
+		}
-	// var x I
+	}()
-	// _ = x.(I)
+	var x I
+	_ = x.(I)
 }
 
 //////////////////////////////////////////////////////////////////////
@@ -488,54 +402,6 @@ func init() {
 	multipleLabels()
 }
 
-////////////////////////////////////////////////////////////////////////
-// Defer
-
-func deferMutatesResults(noArgReturn bool) (a, b int) {
-	defer func() {
-		if a != 1 || b != 2 {
-			panic(fmt.Sprint(a, b))
-		}
-		a, b = 3, 4
-	}()
-	if noArgReturn {
-		a, b = 1, 2
-		return
-	}
-	return 1, 2
-}
-
-func init() {
-	a, b := deferMutatesResults(true)
-	if a != 3 || b != 4 {
-		panic(fmt.Sprint(a, b))
-	}
-	a, b = deferMutatesResults(false)
-	if a != 3 || b != 4 {
-		panic(fmt.Sprint(a, b))
-	}
-}
-
-// We concatenate init blocks to make a single function, but we must
-// run defers at the end of each block, not the combined function.
-var deferCount = 0
-
-func init() {
-	deferCount = 1
-	defer func() {
-		deferCount++
-	}()
-	// defer runs HERE
-}
-
-func init() {
-	// Strictly speaking the spec says deferCount may be 0 or 2
-	// since the relative order of init blocks is unspecified.
-	if deferCount != 2 {
-		panic(deferCount) // defer call has not run!
-	}
-}
-
 func init() {
 	// Struct equivalence ignores blank fields.
 	type s struct{ x, _, z int }
@@ -566,21 +432,6 @@ func init() {
 	_ = i == j // interface comparison recurses on types
 }
 
-// Composite literals
-
-func init() {
-	type M map[int]int
-	m1 := []*M{{1: 1}, &M{2: 2}}
-	want := "map[1:1] map[2:2]"
-	if got := fmt.Sprint(*m1[0], *m1[1]); got != want {
-		panic(got)
-	}
-	m2 := []M{{1: 1}, M{2: 2}}
-	if got := fmt.Sprint(m2[0], m2[1]); got != want {
-		panic(got)
-	}
-}
-
 func init() {
 	// Regression test for SSA renaming bug.
 	var ints []int
@@ -594,42 +445,6 @@ func init() {
 	}
 }
 
-func init() {
-	// Regression test for issue 6806.
-	ch := make(chan int)
-	select {
-	case n, _ := <-ch:
-		_ = n
-	default:
-		// The default case disables the simplification of
-		// select to a simple receive statement.
-	}
-
-	// TODO(adonovan, gri) enable again once we accept issue 8189.
-	// value,ok-form receive where TypeOf(ok) is a named boolean.
-	// type mybool bool
-	// var x int
-	// var y mybool
-	// select {
-	// case x, y = <-ch:
-	// default:
-	// 	// The default case disables the simplification of
-	// 	// select to a simple receive statement.
-	// }
-
-	// TODO(adonovan, gri) remove once we accept issue 8189.
-	var x int
-	var y bool
-	select {
-	case x, y = <-ch:
-	default:
-		// The default case disables the simplification of
-		// select to a simple receive statement.
-	}
-	_ = x
-	_ = y
-}
-
 // Regression test for issue 6949:
 // []byte("foo") is not a constant since it allocates memory.
 func init() {
@@ -655,33 +470,14 @@ func init() {
 		panic(got)
 	}
 	max := 3
-	if v[2] == 42 {
+	if "a"[0] == 'a' {
-		max = 2
+		max = 2 // max is non-constant, even in SSA form
 	}
 	if got := lenCapLoHi(s[1:2:max]); got != [4]int{1, 1, 1, 1} {
 		panic(got)
 	}
 }
 
-// Regression test for issue 7840 (covered by SSA sanity checker).
-func bug7840() bool {
-	// This creates a single-predecessor block with a φ-node.
-	return false && a == 0 && a == 0
-}
-
-// Regression test for range of pointer to named array type.
-func init() {
-	type intarr [3]int
-	ia := intarr{1, 2, 3}
-	var count int
-	for _, x := range &ia {
-		count += x
-	}
-	if count != 6 {
-		panic(count)
-	}
-}
-
 // Test that a nice error is issue by indirection wrappers.
 func init() {
 	var ptr *T
@@ -698,56 +494,3 @@ func init() {
 	i.f()
 	panic("unreachable")
 }
-
-// Test for in-place initialization.
-func init() {
-	// struct
-	type S struct {
-		a, b int
-	}
-	s := S{1, 2}
-	s = S{b: 3}
-	if s.a != 0 {
-		panic("s.a != 0")
-	}
-	if s.b != 3 {
-		panic("s.b != 3")
-	}
-	s = S{}
-	if s.a != 0 {
-		panic("s.a != 0")
-	}
-	if s.b != 0 {
-		panic("s.b != 0")
-	}
-
-	// array
-	type A [4]int
-	a := A{2, 4, 6, 8}
-	a = A{1: 6, 2: 4}
-	if a[0] != 0 {
-		panic("a[0] != 0")
-	}
-	if a[1] != 6 {
-		panic("a[1] != 6")
-	}
-	if a[2] != 4 {
-		panic("a[2] != 4")
-	}
-	if a[3] != 0 {
-		panic("a[3] != 0")
-	}
-	a = A{}
-	if a[0] != 0 {
-		panic("a[0] != 0")
-	}
-	if a[1] != 0 {
-		panic("a[1] != 0")
-	}
-	if a[2] != 0 {
-		panic("a[2] != 0")
-	}
-	if a[3] != 0 {
-		panic("a[3] != 0")
-	}
-}

go/ssa/interp/testdata/defer.go

@@ -0,0 +1,53 @@
+package main
+
+// Tests of defer.  (Deferred recover() belongs is recover.go.)
+
+import "fmt"
+
+func deferMutatesResults(noArgReturn bool) (a, b int) {
+	defer func() {
+		if a != 1 || b != 2 {
+			panic(fmt.Sprint(a, b))
+		}
+		a, b = 3, 4
+	}()
+	if noArgReturn {
+		a, b = 1, 2
+		return
+	}
+	return 1, 2
+}
+
+func init() {
+	a, b := deferMutatesResults(true)
+	if a != 3 || b != 4 {
+		panic(fmt.Sprint(a, b))
+	}
+	a, b = deferMutatesResults(false)
+	if a != 3 || b != 4 {
+		panic(fmt.Sprint(a, b))
+	}
+}
+
+// We concatenate init blocks to make a single function, but we must
+// run defers at the end of each block, not the combined function.
+var deferCount = 0
+
+func init() {
+	deferCount = 1
+	defer func() {
+		deferCount++
+	}()
+	// defer runs HERE
+}
+
+func init() {
+	// Strictly speaking the spec says deferCount may be 0 or 2
+	// since the relative order of init blocks is unspecified.
+	if deferCount != 2 {
+		panic(deferCount) // defer call has not run!
+	}
+}
+
+func main() {
+}

go/ssa/interp/testdata/initorder.go

@@ -1,5 +1,7 @@
 package main
 
+import "fmt"
+
 // Test of initialization order of package-level vars.
 
 var counter int
@@ -38,3 +40,28 @@ var order = makeOrder()
 var a, b = next(), next()
 var c, d = next2()
 var e, f = next(), next()
+
+// ------------------------------------------------------------------------
+
+var order2 []string
+
+func create(x int, name string) int {
+	order2 = append(order2, name)
+	return x
+}
+
+var C = create(B+1, "C")
+var A, B = create(1, "A"), create(2, "B")
+
+// Initialization order of package-level value specs.
+func init() {
+	x := fmt.Sprint(order2)
+	// Result varies by toolchain.  This is a spec bug.
+	if x != "[B C A]" && // gc
+		x != "[A B C]" { // go/types
+		panic(x)
+	}
+	if C != 3 {
+		panic(c)
+	}
+}

go/ssa/interp/testdata/range.go

@@ -0,0 +1,55 @@
+package main
+
+// Tests of range loops.
+
+import "fmt"
+
+// Range over string.
+func init() {
+	if x := len("Hello, 世界"); x != 13 { // bytes
+		panic(x)
+	}
+	var indices []int
+	var runes []rune
+	for i, r := range "Hello, 世界" {
+		runes = append(runes, r)
+		indices = append(indices, i)
+	}
+	if x := fmt.Sprint(runes); x != "[72 101 108 108 111 44 32 19990 30028]" {
+		panic(x)
+	}
+	if x := fmt.Sprint(indices); x != "[0 1 2 3 4 5 6 7 10]" {
+		panic(x)
+	}
+	s := ""
+	for _, r := range runes {
+		s = fmt.Sprintf("%s%c", s, r)
+	}
+	if s != "Hello, 世界" {
+		panic(s)
+	}
+
+	var x int
+	for range "Hello, 世界" {
+		x++
+	}
+	if x != len(indices) {
+		panic(x)
+	}
+}
+
+// Regression test for range of pointer to named array type.
+func init() {
+	type intarr [3]int
+	ia := intarr{1, 2, 3}
+	var count int
+	for _, x := range &ia {
+		count += x
+	}
+	if count != 6 {
+		panic(count)
+	}
+}
+
+func main() {
+}

go/ssa/interp/testdata/static.go

@@ -0,0 +1,58 @@
+package main
+
+// Static tests of SSA builder (via the sanity checker).
+// Dynamic semantics are not exercised.
+
+func init() {
+	// Regression test for issue 6806.
+	ch := make(chan int)
+	select {
+	case n, _ := <-ch:
+		_ = n
+	default:
+		// The default case disables the simplification of
+		// select to a simple receive statement.
+	}
+
+	// value,ok-form receive where TypeOf(ok) is a named boolean.
+	type mybool bool
+	var x int
+	var y mybool
+	select {
+	case x, y = <-ch:
+	default:
+		// The default case disables the simplification of
+		// select to a simple receive statement.
+	}
+	_ = x
+	_ = y
+}
+
+var a int
+
+// Regression test for issue 7840 (covered by SSA sanity checker).
+func bug7840() bool {
+	// This creates a single-predecessor block with a φ-node.
+	return false && a == 0 && a == 0
+}
+
+// A blocking select (sans "default:") cannot fall through.
+// Regression test for issue 7022.
+func bug7022() int {
+	var c1, c2 chan int
+	select {
+	case <-c1:
+		return 123
+	case <-c2:
+		return 456
+	}
+}
+
+// Parens should not prevent intrinsic treatment of built-ins.
+// (Regression test for a crash.)
+func init() {
+	_ = (new)(int)
+	_ = (make)([]int, 0)
+}
+
+func main() {}