use param file

Author: aignas

python/uv/private/lock.bzl

@@ -19,24 +19,33 @@ load("@bazel_skylib//rules:diff_test.bzl", "diff_test")
 load("@bazel_skylib//rules:expand_template.bzl", "expand_template")
 load("//python:py_binary.bzl", "py_binary")
 load("//python/private:bzlmod_enabled.bzl", "BZLMOD_ENABLED")  # buildifier: disable=bzl-visibility
+load("//python/private:text_util.bzl", "render")  # buildifier: disable=bzl-visibility
 
 visibility(["//..."])
 
 _REQUIREMENTS_TARGET_COMPATIBLE_WITH = [] if BZLMOD_ENABLED else ["@platforms//:incompatible"]
 
-def _impl(ctx):
-    args = ctx.actions.args()
+_LockRunInfo = provider(
+    doc = "Information about source tree for Sphinx to build.",
+    fields = {
+        "args": """
+:type: Args
 
-    # TODO @aignas 2025-03-02: create an executable file here that is using a
-    # python and uv toolchains.
+TODO
+""",
+    },
+)
 
+def _lock_impl(ctx):
+    args = ctx.actions.args()
     if ctx.files.maybe_out:
         args.add_all([
             "--src-out",
             ctx.files.maybe_out[0].path,
         ])
     args.add("--output-file", ctx.outputs.out)
     args.add_all(ctx.files.srcs)
+    args.use_param_file("--file=%s", use_always = True)
 
     ctx.actions.run(
         executable = ctx.executable.cmd,
@@ -51,10 +60,13 @@ def _impl(ctx):
         env = ctx.attr.env,
     )
 
-    return [DefaultInfo(files = depset([ctx.outputs.out]))]
+    return [
+        DefaultInfo(files = depset([ctx.outputs.out])),
+        _LockRunInfo(args = args),
+    ]
 
 _lock = rule(
-    implementation = _impl,
+    implementation = _lock_impl,
     doc = """\
 """,
     attrs = {
@@ -71,6 +83,37 @@ _lock = rule(
     },
 )
 
+def _run_lock_impl(ctx):
+    provider = ctx.attr.lock[_LockRunInfo]
+
+    executable = ctx.actions.declare_file(ctx.label.name)
+    ctx.actions.expand_template(
+        template = ctx.file._template,
+        output = executable,
+        substitutions = {
+            "    args = []": "    args = " + render.indent(render.list(provider.args)),
+        },
+        is_executable = True,
+    )
+    fail(provider)
+
+_run_lock = rule(
+    implementation = _run_lock_impl,
+    doc = """\
+""",
+    attrs = {
+        "lock": attr.label(
+            mandatory = True,
+            providers = [_LockRunInfo],
+        ),
+        "_template": attr.label(
+            default = "//python/uv/private:pip_compile.py",
+            allow_single_file = True,
+        ),
+    },
+    executable = True,
+)
+
 def lock(*, name, srcs, out, args = [], **kwargs):
     """Pin the requirements based on the src files.
 
@@ -142,6 +185,7 @@ def lock(*, name, srcs, out, args = [], **kwargs):
             "//python/uv:current_toolchain",
         ] + srcs + ([maybe_out] if maybe_out else []),
         args = run_args,
+        python_version = kwargs.get("python_version"),
         tags = ["manual"],
         deps = ["//python/runfiles"],
     )
@@ -164,6 +208,11 @@ def lock(*, name, srcs, out, args = [], **kwargs):
         cmd = locker_target,
     )
 
+    _run_lock(
+        name = name + ".run2",
+        lock = name,
+    )
+
     if maybe_out:
         diff_test(
             name = name + "_test",

python/uv/private/pip_compile.py

@@ -4,12 +4,15 @@
 import sys
 from pathlib import Path
 
-from python import runfiles
-
 
 def _run() -> None:
-    rfiles = runfiles.Create()
-    uv_path = rfiles.Rlocation("_main/python/uv/current_toolchain/uv")
+    uv_path = ""
+    if not uv_path:
+        from python import runfiles
+
+        rfiles = runfiles.Create()
+        uv_path = rfiles.Rlocation("_main/python/uv/current_toolchain/uv")
+
     if not uv_path:
         raise RuntimeError("cannot find uv: {}".format(uv_path))
 
@@ -20,6 +23,9 @@ def _run() -> None:
     env["UV_INTERNAL__PARENT_INTERPRETER"] = sys.executable
     args = []
     sys_args = sys.argv[1:]
+    if sys_args[0].startswith("--file"):
+        # TODO @aignas 2025-03-10: use argparse.ArgumentParser instead
+        sys_args = Path(sys_args[0].partition("=")[-1]).read_text().strip().split("\n")
 
     src_out = sys_args[1] if sys_args[0] == "--src-out" else None
     if src_out: