Support debugging i386 executables on amd64 host

[dennwc]

1. What version of Delve are you using (dlv version)?

Delve Debugger
Version: 1.4.1
Build: 708eadd5538edd222d8553b08b47c295474f38fa

2. What version of Go are you using? (go version)?

go version go1.13.12 linux/amd64

3. What operating system and processor architecture are you using?

Delve is running on linux/amd64, while debugging the program for linux/386 (running on the same host).

4. What did you do?

Run the debugging session using Goland:

dlv --listen=0.0.0.0:45155 --headless=true --api-version=2 --check-go-version=false --only-same-user=false exec /tmp/___go_build_cmd -- --some-flags

5. What did you expect to see?

A running debugging session, as usual.

6. What did you see instead?

panic: runtime error: slice bounds out of range

goroutine 6 [running]:
github.com/go-delve/delve/pkg/dwarf/frame.parseFDE(0xc0011fa0a0, 0xbe0858)
        /mnt/agent/work/4c3e5e3eabfaf2d2/pkg/dwarf/frame/parser.go:88 +0x2db
github.com/go-delve/delve/pkg/dwarf/frame.Parse(0xc000e94000, 0xa54c4, 0xa54c4, 0xcbbb40, 0x11af820, 0x0, 0x8, 0x0, 0x0, 0x0)
        /mnt/agent/work/4c3e5e3eabfaf2d2/pkg/dwarf/frame/parser.go:36 +0x109
github.com/go-delve/delve/pkg/proc.(*BinaryInfo).parseDebugFrameElf(0xc0001903c0, 0xc0001d40b0, 0xc000033540, 0xc000041ed0)
        /mnt/agent/work/4c3e5e3eabfaf2d2/pkg/proc/bininfo.go:1186 +0x234
created by github.com/go-delve/delve/pkg/proc.loadBinaryInfoElf
        /mnt/agent/work/4c3e5e3eabfaf2d2/pkg/proc/bininfo.go:1142 +0x3d4

[chainhelen]

It do rely on runtime.GOOS, runtime.GOARCH instead of executable at present.

[dennwc]

Thanks for the insight!

Do you mean the environment variables, or the constants in the runtime?

If the later, I guess I will need to run Delve for 386. Or I can send a patch to allow the environment variables first.

[chainhelen]

Delve need to be compiled on i386 platform or cross compile for i386 (please note dlv use cgo when cross compile) .

[dennwc]

I can confirm that Delve works with that binary if 386 version of the tool is used.

[dennwc]

I opened an issue for Goland, to consider bundling 386 Delve version in the meantime.