Add support for verible: language server + fixer (#4994)

* Add support for verible: language server + fixer
* verible: add default flag, rules support for verible-ls

autoload/ale/fix/registry.vim

@@ -742,6 +742,11 @@ let s:default_registry = {
 \       'suggested_filetypes': ['toml'],
 \       'description': 'Lints TOML files',
 \   },
+\   'verible_format': {
+\       'function': 'ale#fixers#verible_format#Fix',
+\       'suggested_filetypes': ['verilog'],
+\       'description': 'Formats verilog files using verible.',
+\   },
 \}
 
 " Reset the function registry to the default entries.

autoload/ale/fixers/verible_format.vim

@@ -0,0 +1,17 @@
+" Author: Nicolas Derumigny <https://github.com/nicolasderumigny>
+" Description: verible formatter for verilog.
+
+call ale#Set('verilog_verible_format_executable', 'verible-verilog-format')
+call ale#Set('verilog_verible_format_options', '')
+
+function! ale#fixers#verible_format#Fix(buffer) abort
+    let l:executable = ale#Escape(ale#Var(a:buffer, 'verilog_verible_format_executable'))
+    let l:command = l:executable
+    let l:options = ale#Var(a:buffer, 'verilog_verible_format_options')
+
+    if l:options isnot# ''
+        let l:command .= ' ' . l:options
+    endif
+
+    return {'command': l:command . ' -'}
+endfunction