From 484e63fbdb0db5fa0d2f63f866e54a2719cec0c4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=98yvind=20Harboe?= <oyvind.harboe@zylin.com>
Date: Fri, 1 May 2026 13:05:12 +0200
Subject: [PATCH] extension: add `yosys_plugins` attribute to orfs.default()
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Lets consumers expose out-of-tree yosys plugins (e.g. yosys-slang)
without having to materialize a custom yosys_share tree.

bazel-orfs now derives YOSYS_PLUGIN_PATH from the dirnames of the
plugin files passed via `yosys_plugins`, and adds them to the input
set of yosys actions. The old single-tree-artifact yosys_share path
is preserved as a fallback when no plugins are specified, so
existing consumers (including downstream/test) keep working.

Tested via The-OpenROAD-Project/OpenROAD#10237 (ditch-docker):
- bazelisk build //:openroad clean
- bazelisk test //test/orfs/... -- all 19 tests pass
- merge_yosys_share custom rule removed in OpenROAD; orfs.default()
  uses yosys_plugins = ["@yosys-slang//src/yosys_plugin:slang.so"]

Signed-off-by: Øyvind Harboe <oyvind.harboe@zylin.com>
---
 config.bzl              |  6 ++++++
 extension.bzl           |  7 +++++++
 private/attrs.bzl       |  7 +++++++
 private/environment.bzl | 20 ++++++++++++++------
 4 files changed, 34 insertions(+), 6 deletions(-)

diff --git a/config.bzl b/config.bzl
index 9b912a3b..b47a3894 100644
--- a/config.bzl
+++ b/config.bzl
@@ -6,6 +6,9 @@ def _global_config_impl(repository_ctx):
         num_cpus = int(result.stdout.strip())
     else:
         num_cpus = 4
+    yosys_plugins_repr = "[" + ", ".join(
+        ['"{}"'.format(p) for p in repository_ctx.attr.yosys_plugins],
+    ) + "]"
     repository_ctx.file(
         "global_config.bzl",
         """
@@ -19,6 +22,7 @@ CONFIG_PDK = "{pdk}"
 CONFIG_YOSYS = "{yosys}"
 CONFIG_YOSYS_ABC = "{yosys_abc}"
 CONFIG_YOSYS_SHARE = "{yosys_share}"
+CONFIG_YOSYS_PLUGINS = {yosys_plugins}
 NUM_CPUS = {num_cpus}
 """.format(
             klayout = repository_ctx.attr.klayout,
@@ -31,6 +35,7 @@ NUM_CPUS = {num_cpus}
             yosys = repository_ctx.attr.yosys,
             yosys_abc = repository_ctx.attr.yosys_abc,
             yosys_share = repository_ctx.attr.yosys_share,
+            yosys_plugins = yosys_plugins_repr,
             num_cpus = num_cpus,
         ),
     )
@@ -68,6 +73,7 @@ global_config = repository_rule(
             cfg = "exec",
         ),
         "yosys_share": attr.label(mandatory = True),
+        "yosys_plugins": attr.label_list(),
     },
     doc = "A repository that provides global configuration values as strings.",
 )
diff --git a/extension.bzl b/extension.bzl
index d73112b5..baa56a46 100644
--- a/extension.bzl
+++ b/extension.bzl
@@ -66,6 +66,12 @@ _default_tag = tag_class(
             mandatory = False,
             default = Label("@yosys//:yosys_share"),
         ),
+        "yosys_plugins": attr.label_list(
+            mandatory = False,
+            doc = "Extra .so plugin files to expose via YOSYS_PLUGIN_PATH " +
+                  "during yosys actions. Use to load out-of-tree plugins " +
+                  "(e.g. yosys-slang) without merging them into yosys_share.",
+        ),
     },
 )
 
@@ -90,6 +96,7 @@ def _orfs_repositories_impl(module_ctx):
             yosys = default.yosys,
             yosys_abc = default.yosys_abc,
             yosys_share = default.yosys_share,
+            yosys_plugins = default.yosys_plugins,
         )
 
         load_json_file(
diff --git a/private/attrs.bzl b/private/attrs.bzl
index dc8a76a9..23b0124d 100644
--- a/private/attrs.bzl
+++ b/private/attrs.bzl
@@ -12,6 +12,7 @@ load(
     "CONFIG_PDK",
     "CONFIG_YOSYS",
     "CONFIG_YOSYS_ABC",
+    "CONFIG_YOSYS_PLUGINS",
     "CONFIG_YOSYS_SHARE",
 )
 load(
@@ -163,6 +164,12 @@ def yosys_only_attrs():
             cfg = "exec",
             default = CONFIG_YOSYS_SHARE,
         ),
+        "_yosys_plugins": attr.label_list(
+            doc = "Extra .so plugin files exposed via YOSYS_PLUGIN_PATH.",
+            allow_files = True,
+            cfg = "exec",
+            default = CONFIG_YOSYS_PLUGINS,
+        ),
     }
 
 def renamed_inputs_attr():
diff --git a/private/environment.bzl b/private/environment.bzl
index 7f0a96ee..265de78d 100644
--- a/private/environment.bzl
+++ b/private/environment.bzl
@@ -55,11 +55,19 @@ def yosys_environment(ctx):
         "YOSYS_EXE": ctx.executable.yosys.path,
     } | orfs_environment(ctx)
 
-    # When yosys_share is a single tree artifact (e.g. merged share with
-    # plugins), tell yosys where to find plugins via YOSYS_PLUGIN_PATH.
-    # BCR yosys discovers plugins via /proc/self/exe and won't find plugins
-    # that live outside its own share/ tree without this hint.
-    if len(ctx.files._yosys_share) == 1:
+    # Tell yosys where to find out-of-tree plugins (e.g. yosys-slang)
+    # via YOSYS_PLUGIN_PATH. BCR yosys discovers plugins via
+    # /proc/self/exe and won't find plugins that live outside its own
+    # share/ tree without this hint.
+    plugin_dirs = []
+    for f in ctx.files._yosys_plugins:
+        if f.dirname not in plugin_dirs:
+            plugin_dirs.append(f.dirname)
+    if plugin_dirs:
+        env["YOSYS_PLUGIN_PATH"] = ":".join(plugin_dirs)
+    elif len(ctx.files._yosys_share) == 1:
+        # Backwards-compat: a single tree-artifact yosys_share with a
+        # plugins/ subdir still works.
         env["YOSYS_PLUGIN_PATH"] = ctx.files._yosys_share[0].path + "/plugins"
     return env
 
@@ -133,7 +141,7 @@ def test_inputs(ctx):
 
 def yosys_inputs(ctx):
     return depset(
-        ctx.files._yosys_share,
+        ctx.files._yosys_share + ctx.files._yosys_plugins,
         transitive = [
             _runfiles(
                 [