Rust: integrate rust code generation into //rust/codegen

rust/codegen/BUILD.bazel

@@ -1,15 +1,17 @@
-load("@bazel_skylib//rules:native_binary.bzl", "native_binary")
+_args = [
+    "//rust/ast-generator",
+    "//rust/ast-generator:manifest",
+    "//misc/codegen",
+    "//rust:codegen-conf",
+]
 
-native_binary(
+sh_binary(
     name = "codegen",
-    src = "//misc/codegen",
-    out = "codegen",
-    args = [
-        "--configuration-file=$(location //rust:codegen-conf)",
-    ],
-    data = [
-        "//rust:codegen-conf",
-        "//rust:schema",
-    ],
+    srcs = ["codegen.sh"],
+    args = ["$(rlocationpath %s)" % a for a in _args],
+    data = _args,
     visibility = ["//rust:__subpackages__"],
+    deps = [
+        "//misc/bazel:sh_runfiles",
+    ],
 )

rust/codegen/codegen.sh

@@ -0,0 +1,13 @@
+#!/bin/bash
+
+set -eu
+
+source misc/bazel/runfiles.sh 2>/dev/null || source external/ql~/misc/bazel/runfiles.sh
+
+ast_generator="$(rlocation "$1")"
+ast_generator_manifest="$(rlocation "$2")"
+codegen="$(rlocation "$3")"
+codegen_conf="$(rlocation "$4")"
+
+CARGO_MANIFEST_DIR="$(dirname "$ast_generator_manifest")" "$ast_generator"
+"$codegen" --configuration-file="$codegen_conf"