fix: initialize arguments and executable path correctly, and dlopen with RTLD_GLOBAL (#8)

* fix: initialize arguments and executable path correctly. fixes numpy issue on darwin
* chore: test importing numpy on ci
* tests: log python version and executable
* fix: workaround for dlopen with RTLD_GLOBAL
* ci: only setup python3 on windows

Author: DjDeveloperr

.github/workflows/checks.yml

@@ -39,10 +39,14 @@ jobs:
         with:
           deno-version: v1.x
 
-      - name: Setup python 3.8
+      - name: Setup Python 3.9 (Windows)
         uses: actions/setup-python@v2
+        if: ${{ matrix.os == 'windows-latest' }}
         with:
-          python-version: '3.8'
+          python-version: '3.9'
+
+      - name: Install NumPy
+        run: python3 -m pip install numpy
 
       - name: Run deno test
         run: deno test --allow-all --unstable

src/ffi.ts

@@ -1,4 +1,4 @@
-import { findLib } from "./util.ts";
+import { cstr, findLib } from "./util.ts";
 
 const lib = Deno.env.get("DENO_PYTHON_PATH") ?? await findLib();
 
@@ -375,6 +375,30 @@ try {
       result: "pointer",
     },
   }).symbols;
+
+  // On Unix based systems, we need to supply dlopen with RTLD_GLOBAL
+  // but Deno.dlopen does not support passing that flag. So we'll open
+  // libc and use its dlopen to open with RTLD_LAZY | RTLD_GLOBAL to
+  // allow subsequently loaded shared libraries to be able to use symbols
+  // from Python C API.
+  if (Deno.build.os === "linux") {
+    // TODO: is it right to use this symbol?
+    const libc = Deno.dlopen(`libc.so.6`, {
+      __libc_dlopen_mode: {
+        parameters: ["pointer", "i32"],
+        result: "pointer",
+      },
+    });
+    libc.symbols.__libc_dlopen_mode(cstr(lib), 0x00001 | 0x00100);
+  } else if (Deno.build.os === "darwin") {
+    const libc = Deno.dlopen(`libc.dylib`, {
+      dlopen: {
+        parameters: ["pointer", "i32"],
+        result: "pointer",
+      },
+    });
+    libc.symbols.dlopen(cstr(lib), 0x00001 | 0x00100);
+  }
 } catch (e) {
   throw new Error(`Python library not found: ${(e as Error).message}`);
 }

src/python.ts

@@ -681,6 +681,18 @@ export class Python {
     this.bool = this.builtins.bool;
     this.set = this.builtins.set;
     this.tuple = this.builtins.tuple;
+
+    // Initialize arguments and executable path,
+    // since some modules expect them to be set.
+
+    const sys = this.import("sys");
+    const os = this.import("os");
+
+    sys.argv = [""];
+
+    if (Deno.build.os === "darwin") {
+      sys.executable = os.path.join(sys.exec_prefix, "bin", "python3");
+    }
   }
 
   /**

test/test.ts

@@ -1,8 +1,11 @@
 import { assert, assertEquals } from "./deps.ts";
 import { NamedArgument, PyObject, python } from "../mod.ts";
 
+const { version, executable } = python.import("sys");
+console.log("Python version:", version);
+console.log("Executable:", executable);
+
 Deno.test("python version", () => {
-  const { version } = python.import("sys");
   assert(String(version).match(/^\d+\.\d+\.\d+/));
 });
 
@@ -111,3 +114,7 @@ Deno.test("named argument", () => {
     "Hello, world!",
   );
 });
+
+Deno.test("numpy", () => {
+  const _np = python.import("numpy");
+});