Workspace: Add Ghidra GDB Python dependencies (#1109)

Give Ghidra a dedicated GDB wrapper whose embedded Python uses its
bundled protobuf and psutil packages, avoiding runtime pip installation
while leaving the normal GDB environment unchanged.

Author: ConnorNelson

workspace/additional/ghidra.nix

@@ -1,12 +1,49 @@
 { pkgs }:
 
-# ghidra will spam-log stack traces into the home directory when not run in a desktop environment
-
 let
   inherit (pkgs.ghidra) pname version meta;
 
   description = "Software reverse engineering (SRE) suite of tools developed by NSA's Research Directorate in support of the Cybersecurity mission";
 
+  ghidraPythonDist = "${pkgs.ghidra}/lib/ghidra/Ghidra/Debug/Debugger-rmi-trace/pypkg/dist";
+
+  ghidraProtobuf = pkgs.python3Packages.buildPythonPackage {
+    pname = "protobuf";
+    version = "3.20.3";
+    format = "wheel";
+    src = "${ghidraPythonDist}/protobuf-3.20.3-py2.py3-none-any.whl";
+    doCheck = false;
+    pythonImportsCheck = [ "google.protobuf" ];
+  };
+
+  ghidraPsutil = pkgs.python3Packages.buildPythonPackage {
+    pname = "psutil";
+    version = "5.9.8";
+    pyproject = true;
+    src = "${ghidraPythonDist}/psutil-5.9.8.tar.gz";
+    build-system = with pkgs.python3Packages; [
+      setuptools
+      wheel
+    ];
+    doCheck = false;
+    pythonImportsCheck = [ "psutil" ];
+  };
+
+  pythonEnv = pkgs.python3.withPackages (_: [
+    ghidraProtobuf
+    ghidraPsutil
+  ]);
+
+  gdb = pkgs.symlinkJoin {
+    name = "ghidra-gdb";
+    paths = [ pkgs.gdb ];
+    nativeBuildInputs = [ pkgs.makeWrapper ];
+    postBuild = ''
+      wrapProgram $out/bin/gdb \
+        --suffix PYTHONPATH : "${pythonEnv}/${pkgs.python3.sitePackages}"
+    '';
+  };
+
 in pkgs.stdenv.mkDerivation {
   inherit pname version meta description;
 
@@ -18,8 +55,11 @@ in pkgs.stdenv.mkDerivation {
       runHook preInstall
 
       mkdir -p "$out/bin"
+
+      # Ghidra will spam-log stack traces into the home directory when not run in a desktop environment.
       makeWrapper "$src/bin/ghidra" \
         "$out/bin/ghidra" \
+        --prefix PATH : "${pkgs.lib.makeBinPath [ gdb ]}" \
         --run 'if [ -z "$DISPLAY" ]; then echo "Error: DISPLAY is not set. Please run under desktop environment." >&2; exit 1; fi'
 
       cp -r "$src/share" "$out/share"