From 1c699c568720929d44500a5dc02174409f29d8c1 Mon Sep 17 00:00:00 2001
From: Gary Guo <gary.guo@lowrisc.org>
Date: Wed, 3 Jan 2024 17:15:13 +0000
Subject: [PATCH] Introduce bazel_ot package

This is bazelisk with auto completion stolen from bazel package.
---
 dev/opentitan.nix         |  4 ++--
 flake.nix                 |  2 +-
 pkgs/bazel_ot/default.nix | 20 ++++++++++++++++++++
 pkgs/default.nix          |  1 +
 4 files changed, 24 insertions(+), 3 deletions(-)
 create mode 100644 pkgs/bazel_ot/default.nix

diff --git a/dev/opentitan.nix b/dev/opentitan.nix
index 766c4e5..5cc4b77 100644
--- a/dev/opentitan.nix
+++ b/dev/opentitan.nix
@@ -1,6 +1,7 @@
 {
   pkgs,
   ncurses5-fhs,
+  bazel_ot,
   python_ot,
   verilator_ot,
   edaTools ? [],
@@ -29,8 +30,7 @@ in
     targetPkgs = _:
       with pkgs;
         [
-          bazelisk
-
+          bazel_ot
           python_ot
           verilator_ot
 
diff --git a/flake.nix b/flake.nix
index 69765ee..078bf9b 100644
--- a/flake.nix
+++ b/flake.nix
@@ -30,7 +30,7 @@
       packages = import ./pkgs {inherit pkgs inputs;};
       devShells = {
         opentitan = pkgs.callPackage ./dev/opentitan.nix {
-          inherit (packages) ncurses5-fhs verilator_ot python_ot;
+          inherit (packages) ncurses5-fhs bazel_ot verilator_ot python_ot;
         };
       };
       formatter = pkgs.alejandra;
diff --git a/pkgs/bazel_ot/default.nix b/pkgs/bazel_ot/default.nix
new file mode 100644
index 0000000..f7ea11b
--- /dev/null
+++ b/pkgs/bazel_ot/default.nix
@@ -0,0 +1,20 @@
+{
+  runCommand,
+  bazelisk,
+  bazel_6,
+  ...
+}:
+# OpenTitan requires a specific version of Bazel.
+# We *could* package our own Bazel, but it can't be a simple override since Bazel build process
+# require a lot of Internet dependencies.
+#
+# For simplicity we'll just let bazelisk do the heavyloading.
+#
+# This package basically just creates an alias from bazel to bazelisk and adds the auto completion
+# which is absent in bazelisk.
+runCommand "bazel" {} ''
+  cp -r ${bazelisk} $out
+  chmod -R +w $out
+  ln -s $out/bin/bazelisk $out/bin/bazel
+  cp -r ${bazel_6}/share $out/share
+''
diff --git a/pkgs/default.nix b/pkgs/default.nix
index 21ecba4..36858bd 100644
--- a/pkgs/default.nix
+++ b/pkgs/default.nix
@@ -11,6 +11,7 @@
 
   verilator_ot = import ./verilator {inherit pkgs;};
   python_ot = pkgs.callPackage ./python_ot {inherit inputs;};
+  bazel_ot = pkgs.callPackage ./bazel_ot {};
 }
 // pkgs.lib.optionalAttrs (pkgs.system == "x86_64-linux") {
   lowrisc-toolchain-gcc-rv32imcb = pkgs.callPackage ./lowrisc-toolchain-gcc-rv32imcb.nix {};