Support for Relative Paths in Yosys scripts

[RCoeurjoly]

Feature Description

Feature Request: Support for Relative Paths in Yosys scripts

Problem Description

When executing a Yosys script (.ys file) that contains relative file paths, Yosys fails if it is not executed from the same directory where the script is. This creates issues when trying to run scripts from different directories.

Example Scenario

Consider the following situation:

• Directory: dir/
  • Files:
    • my_script.ys
    • design.v

Contents of my_script.ys:
read_verilog design.v
Contents of design.v (although not relevant for this feature):

module pass_through(
    input wire a,
    output wire y
);

assign y = a;

endmodule

If I execute Yosys from outside the dir directory, like this:

yosys -p "script dir/my_script.ys"

I get the following error:

/----------------------------------------------------------------------------
| yosys -- Yosys Open SYnthesis Suite |
| Copyright (C) 2012 - 2024 Claire Xenia Wolf [email protected] |
| Distributed under an ISC-like license, type "license" to see terms |
----------------------------------------------------------------------------/
Yosys 0.44+20 (git sha1 e4c8bb0, g++ 11.4.0-1ubuntu1~22.04 -Og -fPIC)

-- Running command `script dir/my_script.ys' --

-- Executing script file dir/my_script.ys' -- ERROR: Can't open input file design.v` for reading: No such file or directory

This happens because Yosys attempts to read design.v from the current directory, not relative to the script's location.

Feature Request

Add a new option to the script command, such as -relative_path.

When -relative_path is used, Yosys should prepend the relative path of the .ys script to all relative file paths mentioned in the script.

Note that this should affect only relative file paths in the script, not absolute paths.

Example Command

yosys -p "script -relative_path dir/my_script.ys"

[povik]

I would find having a way to make sure paths from the script are interpreted relative to the script location very useful, though I would prefer this was controlled by the content of the script rather than passing a flag externally. We already place special meaning on the +/ prefix in paths, maybe we could invent another prefix for this.

[RCoeurjoly]

I would find having a way to make sure paths from the script are interpreted relative to the script location very useful, though I would prefer this was controlled by the content of the script rather than passing a flag externally. We already place special meaning on the +/ prefix in paths, maybe we could invent another prefix for this.

Yeah, that would be a good way also to implement this.