Language Server: implement textDocument/hover

[hzeller]

The Hover request should return some information that can be useful in the context

Ideas:

• Variables: type if available (maybe requires symbol table, but could probably be more simply derived; register/wire/parameter/localparam; if possible to determine without going too much in elaboration-weeds: width. Input, output ?)
• Blocks: when hovering over the end block - if this is a labelled block, name of the label
• generalized to endmodule, endfunction... name of the corresponding thing.

Some simple things can probably be relatively easily be derived, others might need symbol table.

[Saad-Mufti]

Is there any plan for adding hover info for literals, say to show what a binary literal is in hex or decimal? Or utility functions (e.g. $clog2)/other keywords (always_ff), to show parameters + basic info? If not I'd be willing to take a stab at it.

[hzeller]

There are many ideas that could be implemented, alas there is not enough time.
So yes, please take a stab!

[thomas-woehrle]

Hi,

I just wanted to ask which hover functionalities currently exist if any.

The language server README says: verible-verilog-ls by default loads and analyses only currently edited files in the editor. To be able to utilize such features as going to definition, going to references, printing hover info project-wide, add a verible.filelist file to the project.

This indicates that hover info already exists, but it doesn't work for me, while go-to-definition does after setting up verible.filelist, hence my question.

[hzeller]

There is actually some partial hover implementation, but it is disabled right now.

You have to set the hoverProvider value to true and recompile: https://github.com/chipsalliance/verible/blob/master/verilog/tools/ls/verilog-language-server.cc#L90

Reason why it is currently disabled is, that it creates a full symbol table of all files first, while it would be probably better to look in the local file first before doing an expensive symbol table creation.

But, this is a start and can be expanded from there.

[ButterSus]

Hi,

As a workaround, you can use the hover.nvim plugin to implement the default hover behavior. Here's how:
https://gist.github.com/ButterSus/36d47999251030ddf3bbfd187046fe7a

This solution leverages nvim-treesitter and expands the preview until the line containing the definition is fully selected.