Fix nil deref checks for address expressions

test/go/nil_deref_address_test.go

@@ -0,0 +1,130 @@
+package gotest
+
+import (
+	"fmt"
+	"strings"
+	"testing"
+)
+
+type nilDerefAddressStruct struct {
+	i int
+	x [2]int
+}
+
+var nilDerefAddressSink any
+
+func TestNilDerefAddressOperationsPanic(t *testing.T) {
+	tests := []struct {
+		name string
+		f    func()
+	}{
+		{
+			name: "address of dereference",
+			f: func() {
+				var p *int
+				nilDerefAddressSink = &*p
+			},
+		},
+		{
+			name: "field address",
+			f: func() {
+				var p *nilDerefAddressStruct
+				nilDerefAddressSink = &p.i
+			},
+		},
+		{
+			name: "array pointer element address",
+			f: func() {
+				var p *[2]int
+				nilDerefAddressSink = &p[0]
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			expectNilDerefAddressPanic(t, tt.f)
+		})
+	}
+}
+
+func TestNilDerefPrintedCompositeLoadsPanic(t *testing.T) {
+	tests := []struct {
+		name string
+		f    func()
+	}{
+		{
+			name: "slice pointer load",
+			f: func() {
+				var p *[]byte
+				println(*p)
+			},
+		},
+		{
+			name: "string pointer load",
+			f: func() {
+				var p *string
+				println(*p)
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			expectNilDerefAddressPanic(t, tt.f)
+		})
+	}
+}
+
+func TestNilDerefPrintedFieldLoadPanic(t *testing.T) {
+	expectNilDerefAddressPanic(t, func() {
+		var p *nilDerefAddressStruct
+		println(p.i)
+	})
+}
+
+func TestNilDerefInterfaceCopiesPanic(t *testing.T) {
+	tests := []struct {
+		name string
+		f    func()
+	}{
+		{
+			name: "array pointer to interface",
+			f: func() {
+				var p *[4]int
+				nilDerefAddressSink = *p
+			},
+		},
+		{
+			name: "struct pointer to interface",
+			f: func() {
+				var p *nilDerefAddressStruct
+				nilDerefAddressSink = *p
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			expectNilDerefAddressPanic(t, tt.f)
+		})
+	}
+}
+
+func expectNilDerefAddressPanic(t *testing.T, f func()) {
+	t.Helper()
+	defer func() {
+		err := recover()
+		if err == nil {
+			t.Fatal("expected nil pointer dereference panic")
+		}
+		if got := nilDerefAddressPanicString(err); !strings.Contains(got, "nil pointer dereference") {
+			t.Fatalf("panic = %q, want nil pointer dereference", got)
+		}
+	}()
+	f()
+}
+
+func nilDerefAddressPanicString(v any) string {
+	if err, ok := v.(interface{ Error() string }); ok {
+		return err.Error()
+	}
+	return fmt.Sprint(v)
+}

test/go/nil_panic_runtime_error_test.go

@@ -0,0 +1,67 @@
+package gotest
+
+import (
+	"runtime"
+	"strings"
+	"testing"
+)
+
+type nilPanicRuntimeInterface interface {
+	M()
+}
+
+func TestNilPanicValuesAreRuntimeErrors(t *testing.T) {
+	tests := []struct {
+		name string
+		f    func()
+	}{
+		{
+			name: "generic nil interface method",
+			f: func() {
+				nilPanicRuntimeCall[nilPanicRuntimeInterface](nil)
+			},
+		},
+		{
+			name: "nil interface method expression",
+			f: func() {
+				nilPanicRuntimeMethodExpression[int]()
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := expectRuntimeErrorPanic(t, tt.f)
+			if !strings.Contains(err.Error(), "nil pointer dereference") {
+				t.Fatalf("panic = %q, want nil pointer dereference", err.Error())
+			}
+		})
+	}
+}
+
+func nilPanicRuntimeCall[P nilPanicRuntimeInterface](p P) {
+	p.M()
+}
+
+func nilPanicRuntimeMethodExpression[T any]() {
+	interface{ M() T }.M(nil)
+}
+
+func expectRuntimeErrorPanic(t *testing.T, f func()) runtime.Error {
+	t.Helper()
+	var recovered any
+	func() {
+		defer func() {
+			recovered = recover()
+		}()
+		f()
+	}()
+	if recovered == nil {
+		t.Fatal("expected panic")
+	}
+	err, ok := recovered.(runtime.Error)
+	if !ok {
+		t.Fatalf("panic type = %T, want runtime.Error", recovered)
+	}
+	return err
+}

test/goroot/xfail.yaml

@@ -1747,10 +1747,6 @@ xfails:
     directive: run
     case: method5.go
     reason: current main goroot run failure on darwin/arm64
-  - platform: darwin/arm64
-    directive: run
-    case: nilptr2.go
-    reason: current main goroot run failure on darwin/arm64
   - platform: darwin/arm64
     directive: run
     case: noinit.go
@@ -1818,11 +1814,6 @@ xfails:
     directive: run
     case: method5.go
     reason: go1.24 goroot run failure on linux/amd64
-  - version: go1.24
-    platform: linux/amd64
-    directive: run
-    case: nilptr2.go
-    reason: go1.24 goroot run failure on linux/amd64
   - version: go1.24
     platform: linux/amd64
     directive: run
@@ -1898,11 +1889,6 @@ xfails:
     directive: run
     case: method5.go
     reason: go1.25 goroot run failure on linux/amd64
-  - version: go1.25
-    platform: linux/amd64
-    directive: run
-    case: nilptr2.go
-    reason: go1.25 goroot run failure on linux/amd64
   - version: go1.25
     platform: linux/amd64
     directive: run
@@ -1983,11 +1969,6 @@ xfails:
     directive: run
     case: method5.go
     reason: go1.26 goroot run failure on linux/amd64
-  - version: go1.26
-    platform: linux/amd64
-    directive: run
-    case: nilptr2.go
-    reason: go1.26 goroot run failure on linux/amd64
   - version: go1.26
     platform: linux/amd64
     directive: run
@@ -3005,15 +2986,15 @@ xfails:
     reason: current main goroot run failure on darwin/arm64
   - platform: darwin/arm64
     directive: run
-    case: fixedbugs/issue38496.go
+    case: fixedbugs/issue43835.go
     reason: current main goroot run failure on darwin/arm64
   - platform: darwin/arm64
     directive: run
-    case: fixedbugs/issue43835.go
+    case: fixedbugs/issue47928.go
     reason: current main goroot run failure on darwin/arm64
   - platform: darwin/arm64
     directive: run
-    case: fixedbugs/issue47928.go
+    case: fixedbugs/issue38496.go
     reason: current main goroot run failure on darwin/arm64
   - version: go1.26
     platform: darwin/arm64
@@ -3041,10 +3022,6 @@ xfails:
     directive: run
     case: typeparam/chans.go
     reason: select over unbuffered channel misses final receive on darwin/arm64
-  - platform: darwin/arm64
-    directive: run
-    case: typeparam/issue51521.go
-    reason: nil-deref panic value does not implement error on darwin/arm64
   - platform: darwin/arm64
     directive: run
     case: typeparam/mdempsky/15.go
@@ -3065,10 +3042,6 @@ xfails:
     directive: run
     case: fixedbugs/issue26094.go
     reason: current main goroot run failure on linux/amd64
-  - platform: linux/amd64
-    directive: run
-    case: fixedbugs/issue38496.go
-    reason: current main goroot run failure on linux/amd64
   - platform: linux/amd64
     directive: run
     case: fixedbugs/issue43835.go
@@ -3095,6 +3068,10 @@ xfails:
     directive: run
     case: fixedbugs/issue8132.go
     reason: current main goroot run failure on linux/amd64
+  - platform: linux/amd64
+    directive: run
+    case: fixedbugs/issue38496.go
+    reason: current main goroot run failure on linux/amd64
   - version: go1.24
     platform: linux/amd64
     directive: run
@@ -3117,10 +3094,6 @@ xfails:
     directive: run
     case: typeparam/chans.go
     reason: select over unbuffered channel misses final receive on linux/amd64
-  - platform: linux/amd64
-    directive: run
-    case: typeparam/issue51521.go
-    reason: nil-deref panic value does not implement error on linux/amd64
   - platform: linux/amd64
     directive: run
     case: typeparam/mdempsky/15.go