Fix macOS build (#525)

* style: remove some trailing whitespace

* docs: make `identifier-cache` _before_ `jsc`

Running them the other way around results in a failed build.

* docs: `npm i` in both `test/snippets` _and_ `test/scripts`

`test/scripts` has node packages as well. If they aren't installed, then
some of the tests fail to start.

* docs: add `rust` to list of homebrew packages

One of the dependencies tries to run `cargo`, and will fail the build if
it can't. The `cargo` command is provided by the `rust` brew package.

* docs: clean up section on macOS code signing

This requirement applies to _all_ macOS builds, not just those on Apple
Silicon, and also had some slightly confusing wording.

* build: remove leading whitespace from flags

This leading whitespace was making my system treat the argument as a
file with name ` -L$(LLVM_PREFIX)/lib` (leading whitespace included),
instead of as a library path argument.

* build: try llvm@13 first, then fall back on bare llvm

The macOS instructions say to install `llvm@13`, which has a different
path than the bare `llvm` install (`brew --prefix llvm@13` != `brew
--prefix llvm`). This patch takes a slightly smarter approach:

1. If the user defined `LLVM_PREFIX` and it points to a valid path on
   disk, use that.
2. If `LLVM_PREFIX` is NOT a valid path, try setting it to the `llvm@13`
   path.
3. If it's STILL not a valid path, try the plain `llvm` path
4. If it's STILL not valid, set it to a user-friendly error.

There might be a better solution for doing this, I'm not well-versed in
Makefile syntax, but it's at least slightly better than it was before.

* fix(build): update cast signature

`std.math.cast` was changed in 0e6285c8fc31ff866df96847fe34e660da38b4a9.
It used to throw if the cast would overflow, but now it returns `null`
instead.

1 files changed, 6 insertions, 5 deletions

diff --git a/src/futex.zig b/src/futex.zig
index ad8ff84b9..77af4aeca 100644
--- a/src/futex.zig
+++ b/src/futex.zig
@@ -1,7 +1,7 @@
 //! Futex is a mechanism used to block (`wait`) and unblock (`wake`) threads using a 32bit memory address as hints.
 //! Blocking a thread is acknowledged only if the 32bit memory address is equal to a given value.
 //! This check helps avoid block/unblock deadlocks which occur if a `wake()` happens before a `wait()`.
-//! Using Futex, other Thread synchronization primitives can be built which efficiently wait for cross-thread events or signals.  
+//! Using Futex, other Thread synchronization primitives can be built which efficiently wait for cross-thread events or signals.
 
 // This is copy-pasted from Zig's source code to fix an issue with linking on macOS Catalina and earlier.
 
@@ -22,7 +22,7 @@ const spinLoopHint = std.atomic.spinLoopHint;
 /// - The value at `ptr` is no longer equal to `expect`.
 /// - The caller is unblocked by a matching `wake()`.
 /// - The caller is unblocked spuriously by an arbitrary internal signal.
-/// 
+///
 /// If `timeout` is provided, and the caller is blocked for longer than `timeout` nanoseconds`, `error.TimedOut` is returned.
 ///
 /// The checking of `ptr` and `expect`, along with blocking the caller, is done atomically
@@ -200,9 +200,10 @@ const DarwinFutex = struct {
         // true so that we we know to ignore the ETIMEDOUT result.
         var timeout_overflowed = false;
         const status = blk: {
-            const timeout_us = std.math.cast(u32, timeout_ns / std.time.ns_per_us) catch overflow: {
-                timeout_overflowed = true;
-                break :overflow std.math.maxInt(u32);
+            const timeout_us = cast: {
+                const timeout_u32 = std.math.cast(u32, timeout_ns / std.time.ns_per_us);
+                timeout_overflowed = timeout_u32 == null;
+                break :cast timeout_u32 orelse std.math.maxInt(u32);
             };
             break :blk darwin.__ulock_wait(flags, addr, expect, timeout_us);
         };