Add a CLI for creating a debug build (#7)

This is useful for hooking up as a VSCode launch configuration alongside
an LLDB debugger.

.vscode/launch.json

@@ -14,10 +14,10 @@
             "type": "lldb",
             "request": "launch",
             "name": "Debug Example",
-            "preLaunchTask": "zig-test-bin-example",
-            "program": "${workspaceFolder}/example/zig-out/bin/test.bin",
-            "args": [],
-            "cwd": "${workspaceFolder}/example",
+            "initCommands": [
+                "shell poetry run pydust debug ${file}"
+            ],
+            "program": "zig-out/debug.bin",
         },
     ]
 }

.vscode/tasks.json

@@ -4,16 +4,14 @@
         {
             "label": "zig-test-bin",
             "command": "zig",
-            "args": ["build", "-Dtest-debug-root=${file}"],
-            "options": { "cwd": "${workspaceFolder}" },
-            "type": "shell"
-        },
-        {
-            "label": "zig-test-bin-example",
-            "command": "zig",
-            "args": ["build", "-Dtest-debug-root=${file}"],
-            "options": { "cwd": "${workspaceFolder}/example" },
+            "args": [
+                "build",
+                "-Dtest-debug-root=${file}"
+            ],
+            "options": {
+                "cwd": "${workspaceFolder}"
+            },
             "type": "shell"
         },
     ]
-}
+}

pydust/__main__.py

@@ -0,0 +1,44 @@
+import argparse
+import os
+import shutil
+import subprocess
+
+from pydust import config, zigexe
+
+parser = argparse.ArgumentParser()
+sub = parser.add_subparsers(dest="command", required=True)
+
+debug = sub.add_parser("debug", help="Compile a Zig file with debug symbols. Useful for running from an IDE.")
+debug.add_argument("entrypoint")
+
+
+def main():
+    args = parser.parse_args()
+
+    if args.command == "debug":
+        debug(args)
+
+
+def debug(args):
+    """Given an entrypoint file, compile it for test debugging. Placing it in a well-known location."""
+    entrypoint = args.entrypoint
+
+    filename = os.path.basename(entrypoint)
+    name, _ext = os.path.splitext(filename)
+
+    ext_module = config.ExtModule(
+        name=name,
+        root=entrypoint,
+        # Not sure how else we could guess this?
+        limited_api=False,
+    )
+
+    with zigexe.build_argv("test", ext_module, optimize="Debug") as argv:
+        subprocess.run(argv, check=True)
+
+    os.makedirs("zig-out/", exist_ok=True)
+    shutil.move(ext_module.test_bin, "zig-out/debug.bin")
+
+
+if __name__ == "__main__":
+    main()

pydust/build.py

@@ -9,7 +9,8 @@ def build():
     pydust_conf = config.load()
 
     for ext_module in pydust_conf.ext_modules:
-        with zigexe.build_argv("build-lib", ext_module) as argv:
+        # TODO(ngates): figure out if we're running as part of a dev install, or an sdist install?
+        with zigexe.build_argv("build-lib", ext_module, optimize="ReleaseSafe") as argv:
             retcode = subprocess.call(argv)
             if retcode != 0:
                 raise ValueError(f"Failed to compile Zig: {' '.join(shlex.quote(arg) for arg in argv)}")

pydust/src/types/str.zig

@@ -41,6 +41,11 @@ pub const PyString = extern struct {
         return self.appendObj(other.obj);
     }
 
+    pub fn asOwnedSlice(self: PyString) ![:0]const u8 {
+        defer self.decref();
+        return try self.asSlice();
+    }
+
     pub fn asSlice(self: PyString) ![:0]const u8 {
         var size: i64 = 0;
         const buffer: [*]const u8 = ffi.PyUnicode_AsUTF8AndSize(self.obj.py, &size) orelse return PyError.Propagate;

pydust/zigexe.py

@@ -17,9 +17,9 @@
 
 
 @contextlib.contextmanager
-def build_argv(command: Command, ext_module: config.ExtModule):
+def build_argv(command: Command, ext_module: config.ExtModule, optimize: str = "Debug"):
     """The main entry point from Poetry's build script."""
-    argv = [sys.executable, "-m", "ziglang", command]
+    argv = [sys.executable, "-m", "ziglang", command, "-O", optimize]
     if command == "build-lib":
         argv += ["-dynamic"]
         # TODO(ngates): create the correct .so filename based on arch

pyproject.toml

@@ -5,7 +5,7 @@ description = ""
 authors = ["Nicholas Gates <[email protected]>"]
 license = "Apache 2.0"
 readme = "README.md"
-packages = [{include = "pydust"}]
+packages = [{ include = "pydust" }]
 include = ["src"]
 exclude = ["example"]
 
@@ -19,6 +19,9 @@ pytest = "^7.4.0"
 ruff = "^0.0.286"
 black = "^23.7.0"
 
+[tool.poetry.scripts]
+pydust = "pydust.__main__:main"
+
 [tool.black]
 line-length = 120