Can't find definition

[eychun]

I can't seem to use M-x xref-find-definitions to find the definition of reg "a" in the following code with Point at "a" on the 4th line:

module tb; reg[7:0] a; initial begin a = 8'hDA; $display ("[%0t]: a = 0x%0h, b = 0x%0h, c = 0x%0h", $time, a, b, c); end endmodule : tb

I get the following error message in Emacs:

eglot--error: [eglot] Unsupported or ignored LSP capability `:definitionProvider'

I've done M-x verilog-ext-tags-get RET to get tags from the code. I'm using Emacs 29.1.

Here are relevant lines from my .emacs file:

(setq verilog-ext-feature-list '(font-lock xref capf hierarchy eglot lsp flycheck beautify navigation template formatter compilation imenu which-func hideshow typedefs time-stamp block-end-comments ports)) (require 'verilog-ext) (verilog-ext-mode-setup) (add-hook 'verilog-ts-mode-hook #'verilog-ext-mode) (verilog-ext-eglot-set-server 've-svls) ;eglot' config (setq verilog-ext-project-alist (("training" ; Project name :root "/home/eychun/training" ; supports remote dirs via Tramp :files ("*.v") ; Multiple files can be specified through the glob pattern :compile-cmd "make tb_top" ; command used to compile current project :lib-search-path nil))) ; list of dirs to look for include directories or libraries (setq verilog-ext-tags-backend 'tree-sitter)

Here is what I have in my .svls.toml file:

[verilog] include_paths = ["blah.sv"] defines = ["DEBUG", "VAR=1"]

[option] linter = true

Am I missing any steps?

[gmlarumbe]

Hi @eychun ,

Thanks for opening an issue.

The function xref-find-definitions uses only one of the available backends, which in your case seem to be the verilog-ext backend (since you have xref included in verilog-ext-feature-list) and eglot backend (through LSP server svls).

It seems to me that for some reason the verilog-ext xref backend is not active. Can you check the value of the variable xref-backend-functions? Its first element should be verilog-ext-xref-backend. Besides, can you also check if tags have been collected properly on the files in directory ~/.emacs.d/verilog-ext ?

On the other hand, the svls language server only supports diagnostics but not finding definitions, so that is the reason why you are getting the error:

eglot--error: [eglot] Unsupported or ignored LSP capability `:definitionProvider'

[eychun]

Hi @gmlarumbe,

Thank you for your reply to my post. Here is the value of the variable xref-backend-functions:

xref-backend-functions is a variable defined in ‘xref.el’.

Its value is (eglot-xref-backend verilog-ext-xref-backend etags--xref-backend) Local in buffer blah.sv; global value is (etags--xref-backend)

I checked if tags have been collected properly. Here is what I see in ~/.emacs.d/verilog-ext/defs-file-tables:

Here is what my Emacs window looks like:

By the way, I have a question about something you said:

the svls language server only supports diagnostics but not finding definitions

How did you find this information? I couldn't find it in the https://github.com/dalance/svls/blob/master/README.md. Does verilog-ext work with svls? Should I try verilog-ext without svls?

[gmlarumbe]

Seems that eglot is being enabled after verilog-ext when visiting the blah.sv buffer. This results in eglot-xref-backend taking precedence over verilog-ext-xref-backend as it is the first element of the xref-backend-functions list.

I believe the simplest solution could be setting up eglot to not use xref. The following might work:

(setq eglot-stay-out-of '(xref))

How did you find this information? I couldn't find it in the https://github.com/dalance/svls/blob/master/README.md. Does verilog-ext work with svls? Should I try verilog-ext without svls?

The README Feature section only mentions the linter based on svlint. verilog-ext works with svls but it cannot navigate definitions/references because svls itself does not support it.

[eychun]

Thank you. I'm able to jump to definitions now.

After setting up eglot to not use xref, here is the value of xref-backend-functions:

Its value is (verilog-ext-xref-backend etags--xref-backend) Local in buffer blah.sv; global value is (etags--xref-backend)

I'm a little confused by all the pieces necessary for using LSP. I think svls is a language server. Is verilog-ext also a language server? svls works with eglot. Does verilog-ext also work with Eglot or does it work by itself?

[gmlarumbe]

Hi @eychun ,

verilog-ext is an Emacs package that extends the functionality of verilog-mode and verilog-ts-mode to edit SystemVerilog code and provides similar features as LSP does (e.g. find definition).

On the other hand for LSP you need a server (e.g. svls) and a client (e.g. Emacs eglot package). You could configure eglot to connect to svls without the need of verilog-ext. verilog-ext simply provides some basic code to simplify the process for all the current known LSP servers and clients for Verilog.

You can check the wiki entry for more info: https://github.com/gmlarumbe/verilog-ext/wiki/Language-Server-Protocol