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Michael Attenborough > Hardware-Vhdl-Automake > Hardware::Vhdl::Automake


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Hardware::Vhdl::Automake - Automate the compilation of VHDL projects


See Hardware::Vhdl::Automake::Tutorial for a more detailed walk-through of how to set up a project and compile it.

To create a create a new project:

    my $project = Hardware::Vhdl::Automake::Project->new();
    # add some files to it
        $project_dir . '/src/adder.vhd', 
            # explicitly specifying target library and source language
            file => $project_dir . '/src/count_up.vhd', 
            library => 'work', 
            language => 'vhdl-93',
    # change the directory used for the generated hdl files (default would be ~/vhdl/uart/uart_hdlproj_files)
    $project->hdl_dir($project_dir . '/hdl');
    # save the project
    $project->save($project_dir . '/tutorial.hdlproj');

To do an automated compilation:

    use strict;
    use warnings;
    use Hardware::Vhdl::Automake::Project;
    use Hardware::Vhdl::Automake::Compiler::ModelSim;
    my $project_dir = 'C:/hva_tutorial';
    my $modelsim_path = 'C:\ProgramFiles\Modeltech\win32pe';
    # create a new project
    my $project = Hardware::Vhdl::Automake::Project->new();
    # load the project
    $project->load($project_dir . '/tutorial.hdlproj');
    # Tell the project how to report status
    $project->set_status_callback( \&output_status );
    # Generate the HDL files
    # create a ModelSim compiler instance, and tell it where to put its compilation data
    my $compiler = Hardware::Vhdl::Automake::Compiler::ModelSim->new({basedir => $project_dir."/sim"});
    # Tell the compiler object where to find the compiler binaries
    # Tell the compiler how to report status (see the tutorial for an example output_status sub)
    $compiler->set_status_callback( \&output_status );
    # Compile the HDL files
    # save the project, using the last save filename


With this package you can set up a 'project', consisting of a number of VHDL source files, and then with a small script you can compile all the VHDL design units, without worrying about compilation order. Edit your source files, and then the same script will recompile only those VHDL design units that have changed.

You can also benefit from

This is working code - I regularly use it for my own VHDL projects.


I spend a lot of time using ModelSim to design and simulate electronic hardware in VHDL, and I wanted a way to automatically compile only those design units that need to be recompiled, and to do it in the right order. Hardware::Vhdl::Automake is a set of modules to do this, which also allow for pre-processing and the setting of compiler options in the source code. It is developed to the point where I actually find it useful to use, and it works reliably for me. On the other hand, it doesn't have the level of documentation and test code that I would usually consider necessary before uploading to CPAN. I always have too many Perl developments on the go, on top of the work I am actually meant to be doing!

So I'm putting it up as-is, with very little test code but with a tutorial which should be sufficient for people to start getting some productive use out of it. By doing this I'm hoping to get some feedback on whether people find it useful, what features are missing, and what needs to be better documented. So please have a look at it, and tell me whether you found it useful, or confusing, or useless, or what - because if I get no feedback, it will only ever do what I find useful myself. And even that won't be well documented.

I have to warn you that it is currently dependent on using ModelSim, however - although the architecture of the modules allows for different compilers to be used, this would not be simple to add and I can't really develop interfaces for tools that I don't have.

Some notes on how my "auto-compile" tool works

I looked at using 'make', but the problem is working out the dependencies. Every time you add an instantiation of another entity to an architecture, you change the dependencies. A C program tends not to have so many dependency changes during development, but with VHDL you really need to check all the dependencies every time you do a compile. And working out which architecture is used where needs a lot of parsing work, especially when you consider the complexity of 'configuration' statements. I realised there is actually an easier way. If you can split up the design units (e.g. compile entities and architectures, package headers and package bodies, separately), then all you need to do is compile the package headers, then package bodies, then entities, then architectures, then configurations. And no need to compile ones that haven't changed. (Actually this isn't quite true: dependencies between package headers need to be considered. But each of the other groups of design unit type can be compiled in any order).

So what my tool does is to take all the source files in a project and split them up into design units (running them through a pre-processor first if desired), works out which ones have changed since the last compile (by making a digest of significant code tokens), and compiles what needs to be compiled, in the right order. I found it simplest to just always ensure that all the project code is compiled, rather than trying to work out dependencies for a particular target: this avoids the need to parse configurations.

Relationship with Hardware::Vhdl::Lexer and Hardware::Vhdl::Parser

My Lexer module was developed to act as part of these tools.

Hardware::Vhdl::Parser was written (by someone else) before my Lexer, and my Lexer doesn't use it. The Parser does a complete parse of the VHDL code - which would be great, except that it is very slow. It takes a long time to even start up, because of the complexity of building the parser. What I needed this tool to do was to split up the design units so that they could be compiled separately, and that needed just enough parsing to recognise where each design unit ended. The Hardware::Vhdl::Tidy module also does "just enough" parsing to recognise keywords that affect indentation. Both tools use Hardware::Vhdl::Lexer to split up source code into lexical tokens.


Michael Attenborough, <michaelattenborough at yahoo doht co doht uk>


This module requires the following modules to be available:

Hardware::Vhdl::Lexer (version 1.0 or later)
YAML (version 0.62 or later)


Please report any bugs or feature requests to bug-hardware-vhdl-automake at, or through the web interface at I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.


Just email me at <michaelattenborough at yahoo doht co doht uk> - knowing that someone is interested will spur me to writing further features and documentation.


Copyright 2009 Michael Attenborough, all rights reserved.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

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