Vim Syntax Plugin for Verilog and SystemVerilog

About

Based on script originally found at:

http://www.vim.org/scripts/script.php?script_id=1586

IMPORTANT NOTICE

Version 3.0 reviews the configuration variables used in this plugin. As such, take into account that the following variables were deprecated and are no longer supported:

• b:verilog_indent_modules
• b:verilog_indent_preproc
• g:verilog_dont_deindent_eos

The following variables were renamed:

• g:verilog_disable_indent -> g:verilog_disable_indent_lst
• g:verilog_syntax_fold -> g:verilog_syntax_fold_lst

Most configuration variables now also support buffer local variables, allowing exceptions to the default configuration through the use of autocmd.

Features

Besides some bug corrections, the following features were added to this set of scripts:

• Omni completion.
• Configurable syntax folding.
• Matchit settings to support Verilog 2001 and SystemVerilog.
• Error format definitions for common Verilog tools.
• Commands for code navigation.

Omni Completion

This plugin implements an omni completion function that will offer completion suggestions depending on the current context. This will only work if a . character is found in the keyword behind the cursor. At the moment the following contexts are supported:

1. Module instantiation port names.
2. Function/task arguments.
3. Object methods and attributes.

In order to use omni completion a tags file must be generated using the following arguments:

• --extra=+q - Enable hierarchy qualified tags extraction.
• --fields=+i - Enable class inheritance extraction.
• -n - (Optional) Use line number instead of Ex: patterns to identify declaration.

No tool alternative to universal-ctags was tested, but any tool should work seemingly as long as it is able to generate a standard class qualified tags file. For more information on using omni completion please check the vim man page for i_CTRL-X_CTRL-O (the required option omnifunc is automatically defined for the supported file extensions).

Note: Proper SystemVerilog tag generation requires development version of universal-ctags.

Syntax folding

To enable syntax folding set the following option:

let g:verilog_syntax_fold_lst = "all"
set foldmethod=syntax

For more information check the help page :help veriog-fold.

Verilog Compilation and Error format

This plugin includes the errorformat configurations for the following Verilog tools:

• Synopsys VCS (vcs)
• Mentor Modelsim (msim)
• Icarus Verilog (iverilog)
• GPL Cver (cver)
• Synopsys Leda (leda)
• Verilator (verilator)
• Cadence NCVerilog (ncverilog)

The command VerilogErrorFormat allows the interactive selection of these configurations. In some cases it is also possible to ignore lint and/or warning level messages.

A specific tool can be directly selected calling this command with some arguments. Below is an example for VCS:

:VerilogErrorFormat vcs 2

In this example the second argument disables the detection of lint messages. This argument can take the following values:

1. All messages are detected.
2. Ignore lint messages.
3. Ignore lint and warning messages.

After the errorformat has been so defined, it is only a matter of setting makeprg and run :make to call the tool of choice and vim will automatically detect errors, open the required file and place the cursor on the error position. To navigate the error list use the commands :cnext and :cprevious.

For more information check the help page for the quickfix vim feature.

Following an Instance

A framework is provided to follow a module instance to its module declaration as long as its respective entry exists in the tags file. To do so simply execute :VerilogFollowInstance within the instance to follow it to its declaration.

Alternatively, if the cursor is placed over a port of the instance the command :VerilogFollowPort can be used to navigate to the module declaration and immediately searching for that port.

These commands can be mapped as following:

nnoremap <leader>i :VerilogFollowInstance<CR>
nnoremap <leader>I :VerilogFollowPort<CR>

Jump to start of current instance

The command :VerilogGotoInstanceStart is provided to move the cursor to the start of the first module instantiation that precedes the current cursor location.

This command can be mapped as following:

nnoremap <leader>u :VerilogGotoInstanceStart<CR>

Installation

Using vim-plug

1. Add the following to your vimrc:

   Plug 'vhda/verilog_systemverilog.vim'

2. Run:

   $ vim +PlugInstall +qall

Using Vundle

1. Add the following to your vimrc:

   Plugin 'vhda/verilog_systemverilog.vim'

2. Run:

   $ vim +PluginInstall +qall

Using Pathogen

$ cd ~/.vim/bundle
$ git clone https://github.com/vhda/verilog_systemverilog.vim

Other Vim addons helpful for Verilog/SystemVerilog

Matchit

This addon allows using % to jump between matching keywords as Vim already does for matching parentheses/brackets. Many syntax files include the definition of the matching keyword pairs for their supported languages.

Since it is already included in all Vim installations and the addon can be easily loaded by adding the following line to .vimrc:

runtime macros/matchit.vim

Highlight Matchit

The hl_matchit.vim addon complements Matchit by automatically underlining matching words, similarly as Vim already does for parentheses/brackets.

Supertab

Supertab configures the tab key to perform insert completion. To take full advantage of the omni completion functionality the following configuration should be used:

let g:SuperTabDefaultCompletionType = 'context'

When this is done Supertab will choose the most appropriate type of completion to use depending on the current context.

Tagbar

Tagbar allows browsing all variable, functions, tasks, etc within a file in a nice hierarchical view. SystemVerilog language and Verilog/SystemVerilog hierarchical browsing are only supported when used together with the development version of universal-ctags.

The required filetype related configuration for Tagbar is included within this addon.

FastFold

Vim can become very slow in Insert mode when using Syntax Folding and the folds extend across the complete file. The FastFold addon overcomes this limitation by automatically creating manual folds from the syntax generated ones. More information about this problem and on how to configure the addon can be found on its GitHub page.