[nfc] 08-22-24 build cleanup

- Roll bazel 7.2.1 : 7.3.1
- Emphasize that full Xcode is required on macOS – this has been confusing to
  folks before
- Add comments for recently added const casts
- Drop check for *.bazel files for linting, this is already covered by BUILD.*

.bazelversion

@@ -1 +1 @@
-7.2.1
+7.3.1

README.md

@@ -79,7 +79,7 @@ To build `workerd`, you need:
   * LLD 16+ (e.g. package `lld-16`). The build may still succeed if a recent version of GNU gold or the system linker is installed, but lld is highly recommended for link performance.
   * `python3`, `python3-distutils`, and `tcl8.6`
 * On macOS:
-  * Xcode 15 installation (available on macOS 13 and higher). Full Xcode is required, the Xcode command line tools alone are not sufficient for building.
+  * Xcode 15 installation (available on macOS 13 and higher). **Full Xcode is required**, the Xcode command line tools alone are **not sufficient** for building.
   * Homebrew installed `tcl-tk` package (provides Tcl 8.6)
 * On Windows:
   * Install [App Installer](https://learn.microsoft.com/en-us/windows/package-manager/winget/#install-winget)

src/workerd/api/crypto/keys.c++

@@ -90,6 +90,7 @@ kj::Array<kj::byte> AsymmetricKeyCryptoKeyImpl::exportKeyExt(kj::StringPtr forma
   auto bio = OSSL_BIO_MEM();
 
   struct EncDetail {
+    // const_cast is acceptable, pass will be reassigned before it is written to.
     char* pass = const_cast<char*>(&EMPTY_PASSPHRASE[0]);
     size_t pass_len = 0;
     const EVP_CIPHER* cipher = nullptr;

src/workerd/io/actor-cache.h

@@ -267,6 +267,7 @@ class ActorCache final: public ActorCacheInterface {
   ActorCache(rpc::ActorStorage::Stage::Client storage,
       const SharedLru& lru,
       OutputGate& gate,
+      // Hooks has no member variables, so const_cast is acceptable.
       Hooks& hooks = const_cast<Hooks&>(Hooks::DEFAULT));
   ~ActorCache() noexcept(false);
 

src/workerd/io/actor-sqlite.h

@@ -42,6 +42,7 @@ class ActorSqlite final: public ActorCacheInterface, private kj::TaskSet::ErrorH
   explicit ActorSqlite(kj::Own<SqliteDatabase> dbParam,
       OutputGate& outputGate,
       kj::Function<kj::Promise<void>()> commitCallback,
+      // Hooks has no member variables, so const_cast is acceptable.
       Hooks& hooks = const_cast<Hooks&>(Hooks::DEFAULT));
 
   bool isCommitScheduled() {

src/workerd/io/io-gate.h

@@ -54,6 +54,7 @@ class InputGate {
     static const Hooks DEFAULT;
   };
 
+  // Hooks has no member variables, so const_cast is acceptable.
   InputGate(Hooks& hooks = const_cast<Hooks&>(Hooks::DEFAULT));
   ~InputGate() noexcept;
 
@@ -248,6 +249,7 @@ class OutputGate {
     static const Hooks DEFAULT;
   };
 
+  // Hooks has no member variables, so const_cast is acceptable.
   OutputGate(Hooks& hooks = const_cast<Hooks&>(Hooks::DEFAULT));
   ~OutputGate() noexcept(false);
 

tools/cross/format.py

@@ -197,7 +197,7 @@ class FormatConfig:
     FormatConfig(directory=".", globs=("*.py",), formatter=ruff),
     FormatConfig(
         directory=".",
-        globs=("*.bzl", "*.bazel", "WORKSPACE", "BUILD", "BUILD.*"),
+        globs=("*.bzl", "WORKSPACE", "BUILD", "BUILD.*"),
         formatter=buildifier,
     ),
 ]