VM Crash on Type Conversion with Native Type

[omarsy]

Description

I encountered a crash in the Gno VM when performing a type conversion with a native type. The code below demonstrates the issue, where converting a struct to io.Reader causes the VM to crash during execution.

Code Snippet

package main

import "io"

type s struct{}

func (s) Read(p []byte) (n int, err error) {
	return 0, nil
}

func main() {
	var v = (io.Reader)(s{})
	println(v.Read([]byte("test")))
}

Stacktrace

runtime/debug.Stack()
        /Users/ghost/go/pkg/mod/golang.org/[email protected]/src/runtime/debug/stack.go:24 +0x64
runtime/debug.PrintStack()
        /Users/ghost/go/pkg/mod/golang.org/[email protected]/src/runtime/debug/stack.go:16 +0x1c
command-line-arguments.RunFileTest.func1.1()
        /Users/ghost/Documents/projects/teritori/gno/gnovm/tests/file.go:155 +0x1e0
panic({0x104b1ae20?, 0x1400043c900?})
        /Users/ghost/go/pkg/mod/golang.org/[email protected]/src/runtime/panic.go:770 +0x124
github.com/gnolang/gno/gnovm/pkg/gnolang.(*Machine).Stacktrace(0x1400035ed88)
        /Users/ghost/Documents/projects/teritori/gno/gnovm/pkg/gnolang/machine.go:513 +0x2a4
github.com/gnolang/gno/gnovm/pkg/gnolang.(*Machine).RunMain.func1()
        /Users/ghost/Documents/projects/teritori/gno/gnovm/pkg/gnolang/machine.go:840 +0x124
panic({0x104add900?, 0x1400004aaa0?})
        /Users/ghost/go/pkg/mod/golang.org/[email protected]/src/runtime/panic.go:770 +0x124
reflect.Value.assignTo({0x104b00760?, 0x1050cb580?, 0x14000428c98?}, {0x1048626d8, 0xb}, 0x104b19fa0, 0x1400004aa30)
        /Users/ghost/go/pkg/mod/golang.org/[email protected]/src/reflect/value.go:3356 +0x20c
reflect.Value.Set({0x104b19fa0?, 0x1400004aa30?, 0x0?}, {0x104b00760?, 0x1050cb580?, 0x16?})
        /Users/ghost/go/pkg/mod/golang.org/[email protected]/src/reflect/value.go:2325 +0xcc
github.com/gnolang/gno/gnovm/pkg/gnolang.gno2GoValue.func1()
        /Users/ghost/Documents/projects/teritori/gno/gnovm/pkg/gnolang/gonative.go:1067 +0x54
github.com/gnolang/gno/gnovm/pkg/gnolang.gno2GoValue(0x14000432050, {0x104b19fa0?, 0x1400004aa30?, 0x1042710ec?})
        /Users/ghost/Documents/projects/teritori/gno/gnovm/pkg/gnolang/gonative.go:1227 +0x9c0
github.com/gnolang/gno/gnovm/pkg/gnolang.ConvertTo(0x0, {0x104be5290, 0x14000248d20}, 0x14000432050, {0x104bd8110, 0x140004104e0?})
        /Users/ghost/Documents/projects/teritori/gno/gnovm/pkg/gnolang/values_conversions.go:57 +0x180
github.com/gnolang/gno/gnovm/pkg/gnolang.(*Machine).doOpConvert(0x1400035ed88)
        /Users/ghost/Documents/projects/teritori/gno/gnovm/pkg/gnolang/op_expressions.go:799 +0xb0
github.com/gnolang/gno/gnovm/pkg/gnolang.(*Machine).Run(0x1400035ed88)
        /Users/ghost/Documents/projects/teritori/gno/gnovm/pkg/gnolang/machine.go:1492 +0x6c0
github.com/gnolang/gno/gnovm/pkg/gnolang.(*Machine).RunStatement(0x1400035ed88, {0x104bddd28, 0x140003f7300})
        /Users/ghost/Documents/projects/teritori/gno/gnovm/pkg/gnolang/machine.go:954 +0x330
github.com/gnolang/gno/gnovm/pkg/gnolang.(*Machine).RunMain(0x1400035ed88)
        /Users/ghost/Documents/projects/teritori/gno/gnovm/pkg/gnolang/machine.go:845 +0x154
command-line-arguments.RunFileTest.func1(0x7?, 0x104bcf188?, {0x14000285900?, 0x0?}, 0x140001411d0, {0x10485ebb3, 0x4}, {0x10485ebb3, 0x4}, {0x104be5290, ...}, ...)
        /Users/ghost/Documents/projects/teritori/gno/gnovm/tests/file.go:178 +0x7e0
command-line-arguments.RunFileTest({0x140000116c8, 0x5}, {0x140004305e8, 0x11}, {0x14000244450, 0x4, 0x6?})
        /Users/ghost/Documents/projects/teritori/gno/gnovm/tests/file.go:247 +0x238
command-line-arguments.runFileTest(0x140003e01a0, {0x140004305e8, 0x11}, {0x1400036a890, 0x2, 0x104383c98?})
        /Users/ghost/Documents/projects/teritori/gno/gnovm/tests/file_test.go:140 +0x1c8
command-line-arguments.runFileTests.func1(0x140003e01a0?)
        /Users/ghost/Documents/projects/teritori/gno/gnovm/tests/file_test.go:64 +0x38
testing.tRunner(0x140003e01a0, 0x14000141170)
        /Users/ghost/go/pkg/mod/golang.org/[email protected]/src/testing/testing.go:1689 +0xec
created by testing.(*T).Run in goroutine 35
        /Users/ghost/go/pkg/mod/golang.org/[email protected]/src/testing/testing.go:1742 +0x318

Expected Behavior

The program should run without crashing, allowing the Read method of the io.Reader interface to execute properly.

Actual Behavior

The VM crashes with a panic related to the type conversion process.

[thehowl]

named native types are no longer available as of #3119