delve: Backend does not support function calls while trying to modify a string in Delve

Please answer the following before submitting your issue:

Note: Please include any substantial examples (debug session output, stacktraces, etc) as linked gists.

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

Delve Debugger
Version: 1.5.1
Build: f7542d69fe14ca3d43015a19e0094d1bddd9f90e

What version of Go are you using? (go version)? go version go1.13.15 linux/arm64
What operating system and processor architecture are you using? Alpine Linux on aarch64 emulated using QEMU on x86_64 Linux Ubuntu 16.04 host which itself is installed on VirtualBox on a Mac.
What did you do? (dlv) goroutine 50 frame 1 set my_variable = "my_string" Command failed: literal string can not be allocated because function calls are not allowed without using 'call' ALSO: (dlv) call > main.my_function() /usr/lib/go/src/strings/strings.go:308 (hits goroutine(50):1 total:1) (PC: 0x4a929c) Warning: debugging optimized function Command failed: backend does not support function calls
What did you expect to see? Support for changing a string variable
What did you see instead? Quite honestly, I’m not sure since I’m not familiar with using call to modify a string in Delve (if at all possible).

About this issue

Original URL
State: closed
Created 4 years ago
Comments: 27 (4 by maintainers)

Most upvoted comments

Nobody implemented it for 1.18 given the freeze likely not before 1.19.

+75

aarzilli on Nov 25, 2021

Is anyone concerned about this issue?

+72

Yrp on Aug 13, 2021

I still have the same issue on the platform M1 Pro and go 1.18

+26

chenzhiguo on Apr 7, 2022

@avonar given the current regabi transition it’s unrealistic to expect this to happen before a register ABI will exist for arm64. So, not before Go 1.18.

+16

aarzilli on May 8, 2021

how can we force this issue like a community?

+16

avonar on May 8, 2021

Can this now be reopened due to the release of go 1.16 which supports arm64?

+14

machship-mm on Feb 20, 2021

I still have the same error on the platform that go1.17.2 darwin/arm64.

+13

PandyYang on Nov 3, 2021

the issue persists in go version 1.16.3 on darwin/arm64

+13

tede12 on Apr 18, 2021

I still have the error with go version 1.17.2 darwin/arm64

+11

tede12 on Nov 2, 2021

@aarzilli Should this issue be reopened, given that golang/go#50614 is implemented now?

AlekSi on Apr 28, 2022

I’m on go version go1.19.1 darwin/arm64 and I’ve installed the latest dlv under $GOPATH/bin/dlv

$ ./dlv version
Delve Debugger
Version: 1.9.1
Build: $Id: d81b9fd12bfa603f3cf7a4bc842398bd61c42940 $

I’ve added the VM option in goland -Ddlv.path=$GOPATH/bin/dlv to point delve to the local installation

However my application still throws an error when trying to launch in debug mode (with goland). Application error logs

[00] Starting service
[00] API server listening at: [::]:2345
[00] 2022-09-25T00:02:40Z warning layer=rpc Listening for remote connections (connections are not authenticated nor encrypted)
[00] could not launch process: fork/exec /app/testapp: function not implemented

I suspect this is due to some compatibility issue with Mac M1/ARM and go/delve. Any ideas on how to proceed further?

vineetbaldwa on Sep 25, 2022

Reading through all of the linked issues, it’s not clear to me if this is going to be supported by Delve on go1.18. It looks like go1.18.2 has the necessary support. Will there be a corresponding Delve release?

jsumners on May 11, 2022

#2996 Got merged - thanks @aarzilli! I’ll run this through its paces today 😄

Edit: works like a charm. Cherry-picked the change onto the latest release and did the same for the go1.18 source change. Added to GoLand VM options -Ddlv.path=/Users/tinyfluffs/go/bin/dlv, even better. Thanks again

tinyfluffs on May 4, 2022

same for go1.17.3 darwin/arm64, any updates on this?

philous on Nov 25, 2021

Reading through all of the linked issues, it’s not clear to me if this is going to be supported by Delve on go1.18. It looks like go1.18.2 has the necessary support. Will there be a corresponding Delve release?

Just noticed 1.18.2 was released. Cool!

Whenever Delve does its next release, this will be there. The change was merged to the master branch in c9d800edb9a317b01bb643aa42dda7c09f4a1757.

If you want access earlier than that, you can compile Delve straight from the master branch as-is.

tinyfluffs on May 12, 2022

What is required of both Delve and Go on arm64 in order to implement this debugging feature? Since Delve does not support Rosetta for macOS, we’re of course unable to use that with an amd64 build of Go instead.

A patch set in Go’s Gerrit pages has been available for Linux for a little while, however it doesn’t expand to macOS. https://go-review.googlesource.com/c/go/+/395754/

Looking at it, the assembly portion of the change appears to be idempotent no matter the underlying kernel. My best guess is that we can adapt this change to make sure darwin/arm64 is also supported. I think the test suite should be extended with the build tag to include darwin, possibly?

I’m not sure if it’s my setup, but I cherry picked the patch set and built it against the latest copy of the main branch. Delve itself reports the underlying backend still doesn’t support function calls, however. So I’m guessing a change is required to Delve as well?

tinyfluffs on Apr 21, 2022