WIP: Put flatc on the path

Author: dbort

build/pip_data_bin_init.py.in

@@ -0,0 +1,48 @@
+# This file should be written to the wheel package as
+# `executorch/data/bin/__init__.py`.
+#
+# Setuptools will expect to be able to say something like `from
+# executorch.data.bin import mybin; mybin()` for each entry listed in the
+# [project.scripts] section of pyproject.toml. This file makes the `mybin()`
+# function execute the binary at `executorch/data/bin/mybin` and exit with that
+# binary's exit status.
+
+import subprocess
+import os
+import sys
+import types
+
+# This file should live in the target `bin` directory.
+_bin_dir = os.path.join(os.path.dirname(__file__))
+
+def _find_executable_files_under(dir):
+    """Lists all executable files in the given directory."""
+    bin_names = []
+    for filename in os.listdir(dir):
+        filepath = os.path.join(dir, filename)
+        if os.path.isfile(filepath) and os.access(filepath, os.X_OK):
+            bin_names.append(filename)
+    return bin_names
+
+# The list of binaries to create wrapper functions for. An executable should
+# exist for each name under `data/bin/<bin-name>`.
+# @nocommit: see if we can just scrape this from the filesystem to avoid the template
+_bin_names = _find_executable_files_under(_bin_dir)
+
+# We'll define functions named after each binary. Make them importable.
+__all__ = _bin_names
+
+def _run(name):
+    """Runs the named binary, which should live under _bin_dir.
+
+    Exits the current process with the return code of the subprocess.
+    """
+    raise SystemExit(subprocess.call([os.path.join(_bin_dir, name)] + sys.argv[1:], close_fds=False))
+
+# Define a function named after each of the binaries.
+for bin_name in _bin_names:
+    exec(f"def {bin_name}(): _run('{bin_name}')")
+    ### globals()[bin_name] = types.FunctionType(
+    ###     code=f"def {bin_name}(): _run('{bin_name}')",
+    ###     globals=globals(),
+    ### )

pyproject.toml

@@ -33,6 +33,12 @@ dependencies=[
   "zstd",
 ]
 
+# Tell setuptools to generate commandline wrappers for tools that we install
+# under data/bin in the pip package. This will put these commands on the user's
+# path.
+[project.scripts]
+flatc = "executorch.data.bin:flatc"
+
 [tool.setuptools.package-data]
 # @nocommit: prune /test[s]/ dirs, /third-party/ dirs
 # @nocommit: yaml only for kernels?

setup.py

@@ -359,6 +359,14 @@ def run(self):
         data_root = os.path.join(self.build_lib, "executorch", "data")
         self.copy_tree(cmake_install_dir, data_root)
 
+        # Copy the bin wrapper so that users can run any executables under
+        # data/bin, as long as they are listed in the [project.scripts] section
+        # of pyproject.toml.
+        self.copy_file(
+            "build/pip_data_bin_init.py.in",
+            os.path.join(data_root, "bin", "__init__.py"),
+        )
+
         # Finally, run the underlying subcommands like build_py, build_ext.
         build.run(self)