debug: Fails when Delve returns an empty file location

[JadenSimon]

What version of Go, VS Code & VS Code Go extension are you using?

• Run go version to get version of Go from the VS Code integrated terminal.
  • go1.16.3 darwin/amd64
• Run code -v or code-insiders -v to get version of VS Code or VS Code Insiders.
  • 1.55.2
• Check your installed extensions to get the version of the VS Code Go extension
  • 0.24.2 but this bug happens on the latest commit too

Share the Go related settings you have added/edited

All settings are default

Describe the bug

I'm running Delve in headless exec mode in a container. Binary + Delve are cross-compiled for linux/amd64 without optimization. Using the legacy adapter.

The debug client will send a StackTraceRequest to the Delve server. Delve responds correctly except for two functions:
runtime.call64 and runtime.call1024. These appear to be entry points for the Go runtime itself. Delve is unable to properly extract information about these two functions, returning blank file locations (Delve returns a file name for Go1.14 but not Go1.15 or Go1.16). The Go extension does not handle this gracefully, and instead will throw an exception in inferLocalPathFromRemotePath (the actual error is caused by glob.sync).

Suggestion:

If Delve returns an invalid path, treat the source as an unknown instead of failing. A message should also be logged so the Delve team can be notified.

I have a quick-fix for this bug by immediately returning in inferLocalPathFromRemotePath if the path is empty, but I'm sure there is a better solution.

Steps to reproduce the behavior:

Difficult to reproduce since it's dependent on the binary used. My executable also requires a specific set of steps to hit the desired breakpoints.

Logs

An example of the file location being blank (StackTraceRequest):
{"pc":4627612,"file":"","line":0,"function":{"name":"runtime.call1024","value":4627520,"type":0,"goType":0,"optimized":true},"Locals":[],"Arguments":[],"FrameOffset":-2280,"FramePointerOffset":-2296,"Defers":[],"Err":""}

This is when the binary compiled with Go1.14.15:
{"pc":4589589,"file":"/usr/local/go/src/runtime/asm_amd64.s","line":1,"function":{"name":"runtime.call1024","value":4589504,"type":0,"goType":0,"optimized":true},"Locals":[],"Arguments":[],"FrameOffset":-2328,"FramePointerOffset":-2344,"Defers":[],"Err":""}

The empty file location is caused by a bug with Delve (go-delve/delve#2442) but it's likely they won't fix it.

[suzmue]

Thanks for filing this issue! If you would like to send a PR with your fix I would be happy to review it.

[gopherbot]

Change https://golang.org/cl/314190 mentions this issue: debugAdapter: fix missing file bug for remote debugging