feat(aig): make the vendored-PDK root configurable via JACQUARD_VENDOR_DIR

CHANGELOG.md

@@ -12,6 +12,14 @@ the authoritative record.
 
 ### Added
 
+- **`JACQUARD_VENDOR_DIR`** env var to override the vendored-PDK root used
+  for cell-library decomposition (`gf180mcu_fd_sc_mcu7t5v0` /
+  `sky130_fd_sc_hd` functional models). Previously the path was hardcoded
+  to `vendor/` relative to the process CWD, so a consumer running
+  `jacquard` from another working directory had to symlink `vendor/` into
+  place. Now it defaults to `vendor/` (unchanged behaviour) and honours
+  `JACQUARD_VENDOR_DIR` when set. Follows the existing `JACQUARD_*`
+  runtime-knob convention.
 - **Multi-corner support** (WS2.4, commits `5822343` / `530bb36` /
   `59fde04`). `opensta-to-ir` accepts `--liberty NAME=PATH` to attach
   Liberty files to named PVT corners (bare paths still go to a

src/aig.rs

@@ -28,6 +28,26 @@ use indexmap::{IndexMap, IndexSet};
 use netlistdb::{Direction, GeneralPinName, NetlistDB};
 use smallvec::SmallVec;
 
+/// Root directory under which the vendored PDK cell libraries live —
+/// `<root>/gf180mcu_fd_sc_mcu7t5v0` and `<root>/sky130_fd_sc_hd`.
+///
+/// Defaults to `vendor` (the in-repo submodule layout, resolved relative
+/// to the process CWD). Set `JACQUARD_VENDOR_DIR` to override it so a
+/// caller that runs jacquard from a different working directory can point
+/// at the vendored PDKs directly instead of symlinking `vendor/` into its
+/// CWD. Follows the existing `JACQUARD_*` runtime-knob convention.
+fn pdk_vendor_root() -> std::path::PathBuf {
+    pdk_vendor_root_from(std::env::var_os("JACQUARD_VENDOR_DIR"))
+}
+
+/// Pure core of [`pdk_vendor_root`], split out so the env-independent
+/// resolution logic is unit-testable without mutating process env.
+fn pdk_vendor_root_from(override_dir: Option<std::ffi::OsString>) -> std::path::PathBuf {
+    override_dir
+        .map(std::path::PathBuf::from)
+        .unwrap_or_else(|| std::path::PathBuf::from("vendor"))
+}
+
 /// Work item for iterative DFS traversal.
 /// Using two-phase approach: Visit pushes dependencies, Process computes outputs.
 #[derive(Clone, Copy)]
@@ -1732,7 +1752,9 @@ impl AIG {
 
         let pdk = gf180_pdk.expect(
             "GF180 PDK models required for gf180mcu cell decomposition. \
-             Ensure vendor/gf180mcu_fd_sc_mcu7t5v0 submodule is initialized.",
+             Ensure the gf180mcu_fd_sc_mcu7t5v0 PDK is present under the \
+             vendor root (the vendor/ submodule by default, or \
+             $JACQUARD_VENDOR_DIR if set).",
         );
         let model = pdk.models.get(cell_type).unwrap_or_else(|| {
             panic!(
@@ -1853,7 +1875,7 @@ impl AIG {
         });
 
         if has_sky130 {
-            let pdk_path = std::path::PathBuf::from("vendor/sky130_fd_sc_hd/cells");
+            let pdk_path = pdk_vendor_root().join("sky130_fd_sc_hd/cells");
             let mut cell_types: Vec<String> = Vec::new();
             for cellid in 1..netlistdb.num_cells {
                 let celltype = netlistdb.celltypes[cellid].as_str();
@@ -1868,7 +1890,7 @@ impl AIG {
             let pdk_models = crate::sky130_pdk::load_pdk_models(&pdk_path, &cell_types);
             Self::from_netlistdb_impl(netlistdb, Some(&pdk_models), None, cell_library)
         } else if has_gf180mcu {
-            let pdk_path = std::path::PathBuf::from("vendor/gf180mcu_fd_sc_mcu7t5v0");
+            let pdk_path = pdk_vendor_root().join("gf180mcu_fd_sc_mcu7t5v0");
             let mut cell_types: Vec<String> = Vec::new();
             for cellid in 1..netlistdb.num_cells {
                 let celltype = netlistdb.celltypes[cellid].as_str();
@@ -3365,6 +3387,30 @@ impl AIG {
     }
 }
 
+#[cfg(test)]
+mod pdk_vendor_root_tests {
+    use super::*;
+    use std::path::PathBuf;
+
+    #[test]
+    fn defaults_to_vendor_when_unset() {
+        assert_eq!(pdk_vendor_root_from(None), PathBuf::from("vendor"));
+    }
+
+    #[test]
+    fn honours_override_dir() {
+        assert_eq!(
+            pdk_vendor_root_from(Some("/opt/pdks".into())),
+            PathBuf::from("/opt/pdks"),
+        );
+        // Relative overrides are taken verbatim (joined against CWD at use).
+        assert_eq!(
+            pdk_vendor_root_from(Some("some/submodule/vendor".into())),
+            PathBuf::from("some/submodule/vendor"),
+        );
+    }
+}
+
 #[cfg(test)]
 mod xprop_tests {
     use super::*;