Maps and init function not playing nice

[trivigy]

To reproduce simply try to compile the following code:

package main

var test map[string]int

func init() {
	test = make(map[string]int)
	for i := 0; i < 10; i++ {
		test[""] = i
	}
}

func main() {
}

I get the following compilation error:

panic: interface conversion: interp.Value is *interp.LocalValue, not *interp.MapValue

goroutine 1 [running]:
github.com/tinygo-org/tinygo/interp.(*frame).evalBasicBlock(0xc00067a7e8, 0x7f2e18290e40, 0x7f2e18290dc0, 0x34a3f12, 0x4, 0x0, 0x0, 0xc0001a44e8, 0x1, 0x1, ...)
        /home/circleci/project/interp/frame.go:279 +0x92c9
github.com/tinygo-org/tinygo/interp.(*Eval).function(0xc000432120, 0x7f2e1801f8d8, 0xc0001ae760, 0x2, 0x2, 0xc0006ec660, 0xd, 0x34a3f12, 0x4, 0x0, ...)
        /home/circleci/project/interp/interp.go:104 +0x208
github.com/tinygo-org/tinygo/interp.(*frame).evalBasicBlock(0xc00067b310, 0x7f2e18290420, 0x0, 0x0, 0x0, 0xc0182ba918, 0x10, 0x10, 0xc000395d60, 0xa6f821, ...)
        /home/circleci/project/interp/frame.go:449 +0x515a
github.com/tinygo-org/tinygo/interp.(*Eval).function(0xc000432120, 0x7f2e1801f7e8, 0xc00067b450, 0x2, 0x2, 0xc0006ec660, 0xd, 0x0, 0x0, 0x0, ...)
        /home/circleci/project/interp/interp.go:104 +0x208
github.com/tinygo-org/tinygo/interp.(*Eval).Function(...)
        /home/circleci/project/interp/interp.go:87
github.com/tinygo-org/tinygo/interp.Run(0x4c95310, 0x4c8dff0, 0x0, 0x0, 0x0)
        /home/circleci/project/interp/interp.go:74 +0x681
main.Compile(0x7ffe2d091ae5, 0xd, 0x7ffe2d091ac7, 0x10, 0xc000164180, 0xc00067bee0, 0xc00067bd48, 0x0, 0x0)
        /home/circleci/project/main.go:140 +0xc55
main.Build(0x7ffe2d091ae5, 0xd, 0x7ffe2d091ac7, 0x10, 0x7ffe2d091ae0, 0x4, 0xc0000bfee0, 0xc000116260, 0x7f2e2ae7d1b8)
        /home/circleci/project/main.go:337 +0xe2
main.main()
        /home/circleci/project/main.go:696 +0xefd

[trivigy]

Also my workaround for now is:

package main

var test map[string]int

func init() {
	temp := make(map[string]int)
	for i := 0; i < 10; i++ {
		temp[""] = i
	}
        test = temp
}

func main() {
}

[aykevl]

Yes, I'm aware of this. It's currently a limitation of the interp package, which tries to do as much initialization of globals as possible at compile time. This is very important for code size (especially for the unicode package) so can't really be turned off, but needs to be improved to handle this case.

[niaow]

Changes to the interp package appear to have fixed this. The code now compiles and runs.