upstream_wrapper: Generalize upstream_wrapper for rustfmt

...so we can reuse it for more upstream binaries

tools/rustfmt/BUILD.bazel

@@ -85,20 +85,10 @@ rust_clippy(
     ],
 )
 
-# This is a small wrapper around the raw upstream rustfmt binary which can be `bazel run`.
-rust_binary(
+# Deprecated but present for compatibility.
+alias(
     name = "upstream_rustfmt",
-    srcs = [
-        "src/upstream_rustfmt_wrapper.rs",
-    ],
-    data = ["//rust/toolchain:current_rustfmt_toolchain_for_target"],
-    edition = "2018",
-    rustc_env = {
-        "RUSTFMT": "$(rlocationpath //rust/toolchain:current_rustfmt_toolchain_for_target)",
-    },
-    toolchains = ["@rules_rust//rust/toolchain:current_rust_toolchain"],
+    actual = "//tools/upstream_wrapper:upstream_rustfmt",
+    deprecation = "Prefer //tools/upstream_wrapper:upstream_rustfmt",
     visibility = ["//visibility:public"],
-    deps = [
-        "//tools/runfiles",
-    ],
 )

tools/upstream_wrapper/BUILD.bazel

@@ -0,0 +1,29 @@
+load("//rust:defs.bzl", "rust_binary", "rust_clippy", "rust_library")
+load("//tools:tool_utils.bzl", "aspect_repository")
+
+tools = {
+    "rustfmt": "//rust/toolchain:current_rustfmt_toolchain_for_target",
+}
+
+# This is a small wrapper around the raw upstream binary which can be `bazel run`.
+
+[
+    rust_binary(
+        name = "upstream_{}".format(tool_name),
+        srcs = [
+            "src/main.rs",
+        ],
+        data = [target],
+        edition = "2018",
+        rustc_env = {
+            "WRAPPED_TOOL_NAME": tool_name,
+            "WRAPPED_TOOL_TARGET": "$(rlocationpath {})".format(target),
+        },
+        toolchains = ["@rules_rust//rust/toolchain:current_rust_toolchain"],
+        visibility = ["//visibility:public"],
+        deps = [
+            "//tools/runfiles",
+        ],
+    )
+    for (tool_name, target) in tools.items()
+]

tools/rustfmt/src/upstream_rustfmt_wrapper.rs → tools/upstream_wrapper/src/main.rs

@@ -1,23 +1,29 @@
 use std::path::PathBuf;
 use std::process::{exit, Command};
 
+const WRAPPED_TOOL_NAME: &str = env!("WRAPPED_TOOL_NAME");
+const WRAPPED_TOOL_TARGET: &str = env!("WRAPPED_TOOL_TARGET");
+
 fn main() {
     let runfiles = runfiles::Runfiles::create().unwrap();
 
-    let rustfmt = runfiles::rlocation!(runfiles, env!("RUSTFMT"));
-    if !rustfmt.exists() {
-        panic!("rustfmt does not exist at: {}", rustfmt.display());
+    let wrapped_tool_path = runfiles::rlocation!(runfiles, WRAPPED_TOOL_TARGET);
+    if !wrapped_tool_path.exists() {
+        panic!(
+            "{WRAPPED_TOOL_NAME} does not exist at: {}",
+            wrapped_tool_path.display()
+        );
     }
 
     let working_directory = std::env::var_os("BUILD_WORKING_DIRECTORY")
         .map(PathBuf::from)
         .unwrap_or_else(|| std::env::current_dir().expect("Failed to get working directory"));
 
-    let status = Command::new(rustfmt)
+    let status = Command::new(wrapped_tool_path)
         .current_dir(&working_directory)
         .args(std::env::args_os().skip(1))
         .status()
-        .expect("Failed to run rustfmt");
+        .unwrap_or_else(|e| panic!("Failed to run {WRAPPED_TOOL_NAME} {:#}", e));
     if let Some(exit_code) = status.code() {
         exit(exit_code);
     }