run-drc-for-cell-gds-using-magic: Enable running in a directory.

Add a command line argument to allow the check to look for the `./cells`
in a directory other than the current working directory.

Signed-off-by: Tim 'mithro' Ansell <tansell@google.com>

run-drc-for-cell-gds-using-magic/action.yml

diff --git a/run-drc-for-cell-gds-using-magic/action.yml b/run-drc-for-cell-gds-using-magic/action.yml
index dd5e06e..d7b39d6 100644
--- a/run-drc-for-cell-gds-using-magic/action.yml
+++ b/run-drc-for-cell-gds-using-magic/action.yml
@@ -20,6 +20,10 @@
   directory.
 
 inputs:
+  top:
+    description: >-
+        What directory to run the check inside.
+    default: .
   acceptable-errors-file:
     description: >-
         A file containing a list of newline-delimited acceptable DRC errors.
@@ -38,6 +42,8 @@
   using: 'docker'
   image: docker://gcr.io/skywater-pdk/actions/run-drc-for-cell-gds-using-magic:main
   args:
+  - --top
+  - ${{ inputs.top }}
   - --acceptable-errors-file
   - ${{ inputs.acceptable-errors-file }}
   - --match-directories

run-drc-for-cell-gds-using-magic/run_all_drc.py

diff --git a/run-drc-for-cell-gds-using-magic/run_all_drc.py b/run-drc-for-cell-gds-using-magic/run_all_drc.py
index 5adcbcd..9ba9605 100644
--- a/run-drc-for-cell-gds-using-magic/run_all_drc.py
+++ b/run-drc-for-cell-gds-using-magic/run_all_drc.py
@@ -135,6 +135,13 @@
 
 @click.command()
 @click.option(
+    "-t",
+    "--top",
+    default=".",
+    help="Directory to run the process inside."
+         " Default: Current working directory"
+)
+@click.option(
     "-a",
     "--acceptable-errors-file",
     default="/dev/null",
@@ -156,8 +163,10 @@
          " thus do not cause a non-zero exit upon failure."
          " Default: empty string (None of them.)"
 )
-def run_all_drc(acceptable_errors_file, match_directories, known_bad):
-    print("Testing cells in directories matching /%s/…" % match_directories)
+def run_all_drc(top, acceptable_errors_file, match_directories, known_bad):
+    os.chdir(top)
+    print("Testing cells in %s directories matching /%s/…" % (
+        os.getcwd(), match_directories))
 
     global acceptable_errors
     acceptable_errors_str = open(acceptable_errors_file).read()