Emitted functions report an exception by returning with the thread's
pending flag set, and every caller tests the flag after each call that
may throw. On Linux executables (glibc and musl), functions reached only
by direct calls now propagate exceptions by unwinding the native stack
instead:
- unwindAbiFunctions selects the may-throw functions that are not async
or generators, constructors, virtually called or overridden methods,
closure targets, the entry, library exports, module initializers or
callees of coroutine bodies.
- A native unwind costs about 2 µs a raise and 0.1 µs a frame, so functions that
exceptions are likely to cross keep the flag: those with a `throw` of
their own, those up to three calls above one, and recursive functions,
counting calls through methods, closures and callbacks.
- Their propagating exits call scr_unwind_raise (scr_unwind.c), a forced
unwind through _Unwind_ForcedUnwind with the exception still in the
active cell.
- Direct calls to them are `invoke`s without a pending check. The
landing pad runs the frame's usual unwind path: it releases the frame's
values and then enters the enclosing try handler or resumes the unwind.
- Remaining plain calls to them (wrappers, adapters, runtime-facing entry
points) become invokes whose landing pad continues on the pending flag,
or resumes when the wrapper is itself invoked. Every other call is
marked `nounwind`, so inlining a raising function at an invoke keeps its
calls plain.
- When emitted text breaks these rules (a raising function's address is
taken, or an invoked function returns with the flag pending), the
module is emitted again with those functions on the pending flag.
Emitted code does not declare scr_unwind_raise `noreturn`, so sanitized
builds do not run the sanitizer's no-return hook, which needs stack
bounds that fiber stacks do not report. Instead, scr_unwind_raise clears
the shadow of the frames it unwinds.
Executables link a static unwinder: libgcc_eh with the host toolchain and
the glibc runtime packs, and Zig's libunwind with Zig and the musl packs.
macOS, Windows, Android, WASI, libraries and debug builds keep the
pending flag everywhere and emit the same code as before.
The throw-chains runtime workload measures exceptions caught 2, 5 and 20
recursive calls above the throw, through direct calls and a callback,
and a parser that backtracks by throwing.
- Enforce oxlint and oxfmt for owned JavaScript and TypeScript with independent CI checks.
- Preserve compiler import boundaries and protected fixtures while cleaning up lint findings.
- Standardize source formatting and validate import, fixture, and embedded-source protections.
- Remove C emission, debugging options, and automatic backend fallback.
- Complete LLVM lowering and native bootstrap coverage across supported targets.
- Link executables and libraries with precompiled C runtime packs, including iOS and Android.
- Pin GNU runtime packs to glibc 2.36 Zig targets and reject incompatible imports.
- Provision verified Zig builds and exercise published artifacts on Debian Bookworm.
Fixes#349
Co-authored-by: Cruel <383999+Cruel@users.noreply.github.com>
* Expand LLVM native output targets
- Add owned helper and runtime-pack contracts for macOS x64, Linux glibc/musl, Windows x64, and WASI.
- Generalize LLVM target selection, package validation, linker plans, and release/CI matrices.
- Document linker boundaries and add focused native-output and runtime-pack coverage.
* Pin Windows LLVM helper CI to VS 2022
The official LLVM archive needs the Visual Studio 2022 CMake generator, which is not guaranteed by windows-latest.
* Align bootstrap cache with LLVM runtime-pack builds
Use the same target-specific helper and linker identity before and after compiler loading so routed executable cache hits remain lightweight.
* Install Windows LLVM CI tools with Chocolatey
windows-2022 includes Visual Studio but not winget; use its available Chocolatey bootstrap for CMake and Ninja.
* Prevent Zig version probes from leaving runtime-pack objects
Run runtime-pack compiler version probes in a private temporary directory and remove the accidental tracked WASI a.o file.
* Use 7-Zip for Windows LLVM setup
Extract the official LLVM development archive with two-stage 7-Zip instead of Windows tar.exe, which timed out while materializing the toolchain tree.
* Define ssize_t for the MSVC runtime pack
Clang's MSVC target does not expose POSIX ssize_t through sys/types.h; define the pointer-sized runtime type without affecting MinGW.
* Build the Windows runtime pack with Zig
Use the MinGW-compatible Windows sysroot required by the runtime while retaining COFF helper output and installing Zig in the Windows native CI lane.
* Give macOS LLVM differential shard time to finish
Shard 1 passed its setup and focused contracts but was cancelled during its cold LLVM differential slice at the 20-minute job limit.
Chris Tate