## Summary
- `bun run build:local` now handles everything: configuring JSC,
building JSC, and building Bun in a single command on all platforms
(macOS, Linux, Windows). Previously required manually running `bun run
jsc:build:debug`, deleting a duplicate `InspectorProtocolObjects.h`
header, and then running the Bun build separately.
- Incremental JSC rebuilds: JSC is built via `add_custom_target` that
delegates to JSC's inner Ninja, which tracks WebKit source file changes
and only rebuilds what changed. `ninja -Cbuild/debug-local` also works
after the first build.
- Cross-platform support:
- macOS: Uses system ICU automatically
- Linux: Uses system ICU via find_package instead of requiring bundled
static libs
- Windows: Builds ICU from source automatically (only when libs don't
already exist), sets up static CRT and ICU naming conventions
### Changes
- cmake/tools/SetupWebKit.cmake: Replace the old WEBKIT_LOCAL block
(which just set include paths and assumed JSC was pre-built) with full
JSC configure + build integration for all platforms
- cmake/targets/BuildBun.cmake: Add jsc as a build dependency, use
system ICU on Linux for local builds, handle bmalloc linking for local
builds
- CONTRIBUTING.md / docs/project/contributing.mdx: Simplify "Building
WebKit locally" docs from ~15 lines of manual steps to 3 lines
## Test plan
- [x] macOS arm64: clean build, incremental rebuild, WebKit source
change rebuild
- [x] Windows x64: clean build with ICU, incremental rebuild with ICU
skip
- [x] Linux x64: build with system ICU via find_package
- [x] No duplicate InspectorProtocolObjects.h errors
- [x] build/debug-local/bun-debug --version works
Generated with [Claude Code](https://claude.com/claude-code)
Co-authored-by: Claude <noreply@anthropic.com>
## Summary
Add a CI step that runs JSC JIT stress tests under QEMU when
`SetupWebKit.cmake` is modified. This complements #26571 (basic baseline
CPU verification) by also testing JIT-generated code.
## Motivation
PR #26571 added QEMU-based verification that catches illegal
instructions in:
- Startup code
- Static initialization
- Basic interpreter execution
However, JIT compilers (DFG, FTL, Wasm BBQ/OMG) generate code at runtime
that could emit AVX or LSE instructions even if the compiled binary
doesn't. The JSC stress tests from #26380 exercise all JIT tiers through
hot loops that trigger tier-up.
## How it works
1. Detects if `cmake/tools/SetupWebKit.cmake` is modified in the PR
2. If WebKit changes are detected, runs `verify-jit-stress-qemu.sh`
after the build
3. Executes all 78 JIT stress test fixtures under QEMU with restricted
CPU features:
- x64: `qemu-x86_64 -cpu Nehalem` (SSE4.2, no AVX)
- aarch64: `qemu-aarch64 -cpu cortex-a53` (ARMv8.0-A, no LSE)
4. Any SIGILL from JIT-generated code fails the build
## Platforms tested
| Target | CPU Model | What it catches |
|---|---|---|
| `linux-x64-baseline` | Nehalem | JIT emitting AVX/AVX2/AVX512 |
| `linux-x64-musl-baseline` | Nehalem | JIT emitting AVX/AVX2/AVX512 |
| `linux-aarch64` | Cortex-A53 | JIT emitting LSE atomics, SVE |
| `linux-aarch64-musl` | Cortex-A53 | JIT emitting LSE atomics, SVE |
## Timeout
The step has a 30-minute timeout since QEMU emulation is ~10-50x slower
than native. This only runs on WebKit update PRs, so it won't affect
most CI runs.
## Refs
- #26380 - Added JSC JIT stress tests
- #26571 - Added basic QEMU baseline verification
Fixes illegal instruction (SIGILL) crashes on ARMv8.0 aarch64 CPUs
(Cortex-A53, Raspberry Pi 4, AWS a1 instances).
## Root cause
Upstream mimalloc force-enables `MI_OPT_ARCH` on arm64, which adds
`-march=armv8.1-a` and emits LSE atomic instructions (`casa`, `swpa`,
`ldaddl`). These are not available on ARMv8.0 CPUs.
## Fix
- Pass `MI_NO_OPT_ARCH=ON` to mimalloc on aarch64 (has priority over
`MI_OPT_ARCH` in mimalloc's CMake)
- Update WebKit to autobuild-596e48e22e3a1090e5b802744a7938088b1ea860
which explicitly passes `-march` flags to the WebKit build
## Verification
Includes QEMU-based baseline CPU verification CI steps (#26571) that
catch these regressions automatically.
## Summary
- Updates oven-sh/mimalloc bun-dev3 branch to latest upstream
microsoft/mimalloc dev3 (ffa38ab8)
- Merged 12 new commits from upstream
### Key upstream changes included:
- fix re-initialization of threads on macOS
- add lock for sub-pagemap allocations
- fix peak commit stat
- fix use of continue in bitmap find_and_clear (fixes rare case of not
finding space while it exists)
## Test plan
- [ ] CI passes
- [ ] Memory allocation tests pass
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
### What does this PR do?
Updates WebKit to
5b6a0ac49b
### How did you verify your code works?
---------
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Jarred Sumner <jarred@jarredsumner.com>
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
## What does this PR do?
Fixes CMake "No jobs found" error during the build-bun step in CI by
using `BUILDKITE_BUILD_NUMBER` instead of `BUILDKITE_BUILD_ID` (UUID)
for the Buildkite API URL.
### Problem
When `BUN_LINK_ONLY=ON`, `SetupBuildkite.cmake` fetches build info from
the Buildkite API to download artifacts from earlier build steps
(build-cpp, build-zig).
The `BUILDKITE_BUILD_ID` environment variable contains a UUID (e.g.,
`019bee3e-da45-4e9f-b4d8-4bdb5aeac0ac`). When this UUID is used in the
URL, Buildkite returns a **302 redirect** to the numeric build number
URL (e.g., `/builds/35708`).
CMake's `file(DOWNLOAD)` command **does not follow HTTP redirects**, so
the downloaded file is empty. Parsing the empty JSON yields 0 jobs,
triggering the fatal error:
```
CMake Error at cmake/tools/SetupBuildkite.cmake:67 (message):
No jobs found:
https://buildkite.com/bun/bun/builds/019bee3e-da45-4e9f-b4d8-4bdb5aeac0ac
```
### Solution
Prefer `BUILDKITE_BUILD_NUMBER` (numeric, e.g., `35708`) when available,
which doesn't redirect. This environment variable is automatically set
by Buildkite.
## How did you verify your code works?
- Verified UUID URL returns 302: `curl -sS -w '%{http_code}'
"https://buildkite.com/bun/bun/builds/019bee3e-da45-4e9f-b4d8-4bdb5aeac0ac"`
→ `302`
- Verified numeric URL returns 200 with JSON: `curl -sS -H "Accept:
application/json" "https://buildkite.com/bun/bun/builds/35708"` → valid
JSON with jobs array
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
### What does this PR do?
Updates WebKit to
87c6cde57d
### How did you verify your code works?
---------
Co-authored-by: Jarred Sumner <jarred@jarredsumner.com>
## What does this PR do?
Updates the oven-sh/tinycc fork to the latest upstream TinyCC,
incorporating 30+ upstream commits while preserving all Bun-specific
patches.
### Upstream changes incorporated
- Build system improvements (c2str.exe handling, cross-compilation)
- macOS 15 compatibility fixes
- libtcc debugging support
- pic/pie support for i386
- arm64 alignment and symbol offset fixes
- RISC-V 64 improvements (pointer difference, assembly, Zicsr extension)
- Relocation updates
- Preprocessor improvements (integer literal overflow handling)
- x86-64 cvts*2si fix
- Various bug fixes
### Bun-specific patches preserved
- Fix crash on macOS x64 (libxcselect.dylib memory handling)
- Implement `-framework FrameworkName` on macOS (for framework header
parsing)
- Add missing #ifdef guards for TCC_IS_NATIVE
- Make `__attribute__(deprecated)` a no-op
- Fix `__has_include` with framework paths
- Support attributes after identifiers in enums
- Fix dlsym behavior on macOS (RTLD_SELF first, then RTLD_DEFAULT)
- Various tccmacho.c improvements
### Related PRs
- TinyCC fork CI is passing:
https://github.com/oven-sh/tinycc/actions/runs/21105489093
## How did you verify your code works?
- [x] TinyCC fork CI passes on all platforms (Linux
x86_64/arm64/armv7/riscv64, macOS x86_64/arm64, Windows i386/x86_64)
- [ ] Bun CI passes
🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
### What does this PR do?
Without this change, building with `-DWEBKIT_LOCAL=ON` fails with:
```
/work/bun/src/bun.js/bindings/BunObject.cpp:12:10: fatal error: 'JavaScriptCore/JSBase.h' file not found
12 | #include <JavaScriptCore/JSBase.h>
| ^~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.
```
The reason for this is because the directory structure differs between
downloaded and local WebKit.
Downloaded WebKit:
```
build/debug/cache/webkit-6d0f3aac0b817cc0/
└── include/
└── JavaScriptCore/
└── JSBase.h ← Direct path
```
Local WebKit:
```
vendor/WebKit/WebKitBuild/Debug/
└── JavaScriptCore/Headers/
└── JavaScriptCore/
└── JSBase.h ← Nested path
```
The include paths are thus configured differently for each build type.
For Remote WebKit (when WEBKIT_LOCAL=OFF):
- SetupWebKit.cmake line 22 sets: WEBKIT_INCLUDE_PATH =
${WEBKIT_PATH}/include
- BuildBun.cmake line 1253 adds:
include_directories(${WEBKIT_INCLUDE_PATH})
- This resolves to: build/debug/cache/webkit-6d0f3aac0b817cc0/include/
- So #include <JavaScriptCore/JSBase.h> finds the file at
include/JavaScriptCore/JSBase.h ✅
For Local WebKit (when WEBKIT_LOCAL=ON):
- The original code only added:
${WEBKIT_PATH}/JavaScriptCore/Headers/JavaScriptCore
- This resolves to:
vendor/WebKit/WebKitBuild/Debug/JavaScriptCore/Headers/JavaScriptCore/
- So #include <JavaScriptCore/JSBase.h> fails because there's no
JavaScriptCore/ subdirectory at that level ❌
- The fix adds: ${WEBKIT_PATH}/JavaScriptCore/Headers
- Now the include path includes:
vendor/WebKit/WebKitBuild/Debug/JavaScriptCore/Headers/
- So #include <JavaScriptCore/JSBase.h> finds the file at
Headers/JavaScriptCore/JSBase.h ✅
### How did you verify your code works?
Built locally.
Co-authored-by: Carl Smedstad <carsme@archlinux.org>
### What does this PR do?
In CMake, failure to execute a process will place a message string in
the RESULT_VARIABLE. If the message string starts with 'No' such as in
'No such file or directory' then CMake will interpret that as the
boolean false and not halt the build. The new code uses a built-in
option to halt the build on any failure, so the script will halt
correctly if that error occurs. This could also be fixed by quoting, but
might as well use the CMake feature.
I encountered this error when I improperly defined BUN_EXECUTABLE.
### How did you verify your code works?
<details>
<summary>Ran the build with invalid executable path:</summary>
```
$ node ./scripts/build.mjs \
-GNinja \
-DCMAKE_BUILD_TYPE=Debug \
-B build/debug \
--log-level=NOTICE \
-DBUN_EXECUTABLE="foo" \
-DNPM_EXECUTABLE="$(which npm)" \
-DZIG_EXECUTABLE="$(which zig)" \
-DENABLE_ASAN=OFF
Globbed 1971 sources [178.21ms]
CMake Configure
$ cmake -G Ninja -DCMAKE_BUILD_TYPE=Debug -B /work/bun/build/debug --log-level NOTICE -DBUN_EXECUTABLE=foo -DNPM_EXECUTABLE=/bin/npm -DZIG_EXECUTABLE=/bin/zig -DENABLE_ASAN=OFF -S /work/bun -DCACHE_STRATEGY=auto
sccache: Using local cache strategy.
```
</details>
Result:
```
CMake Error at cmake/targets/BuildBun.cmake:422 (execute_process):
execute_process failed command indexes:
1: "Abnormal exit with child return code: no such file or directory"
Call Stack (most recent call first):
CMakeLists.txt:66 (include)
```
### What does this PR do?
Before this change, downloading WebKit would fail silently if there were
e.g. a connection or TLS certificate issue. I experienced this when
trying to build bun in an overly-restrictive sandbox.
After this change, the failure reason will be visible.
### How did you verify your code works?
<details>
<summary>Brought down my network interface and ran the build:</summary>
```sh
$ node ./scripts/build.mjs \
-GNinja \
-DCMAKE_BUILD_TYPE=Debug \
-B build/debug \
--log-level=NOTICE \
-DBUN_EXECUTABLE="$(which node)" \
-DNPM_EXECUTABLE="$(which npm)" \
-DZIG_EXECUTABLE="$(which zig)" \
-DENABLE_ASAN=OFF
Globbed 1971 sources [180.67ms]
CMake Configure
$ cmake -G Ninja -DCMAKE_BUILD_TYPE=Debug -B /work/bun/build/debug --log-level NOTICE -DBUN_EXECUTABLE=/bin/node -DNPM_EXECUTABLE=/bin/npm -DZIG_EXECUTABLE=/bin/zig -DENABLE_ASAN=OFF -S /work/bun -DCACHE_STRATEGY=auto
sccache: Using local cache strategy.
...
```
</details>
Result:
```
CMake Error at cmake/tools/SetupWebKit.cmake:99 (message):
Failed to download WebKit: 6;"Could not resolve hostname"
Call Stack (most recent call first):
cmake/targets/BuildBun.cmake:1204 (include)
CMakeLists.txt:66 (include)
```
## Summary
- Fix CMake JSON parsing error when Buildkite API returns commit
messages with newlines
CMake's `file(READ ...)` reads files with literal newlines, which breaks
`string(JSON ...)` when the JSON contains escape sequences like `\n` in
string values (e.g., commit messages from Buildkite API).
Use `file(STRINGS ...)` to read line-by-line, then join with `\n` to
preserve valid JSON escape sequences while avoiding literal newlines.
## Test plan
- Verify CMake configure succeeds when Buildkite build has commit
messages with newlines
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
### What does this PR do?
Enables `CHECK_REF_COUNTED_LIFECYCLE` in WebKit (
https://github.com/oven-sh/WebKit/pull/121 )
See also
a978fae619
#### `CHECK_REF_COUNTED_LIFECYCLE`?
A compile-time macro that enables lifecycle validation for
reference-counted objects in debug builds.
**Definition**
```cpp
#if ASSERT_ENABLED || ENABLE(SECURITY_ASSERTIONS)
#define CHECK_REF_COUNTED_LIFECYCLE 1
#else
#define CHECK_REF_COUNTED_LIFECYCLE 0
#endif
```
**Purpose**
Detects three categories of bugs:
1. Missing adoption - Objects stored in RefPtr without using adoptRef()
2. Ref during destruction - ref() called while destructor is running
(causes dangling pointers)
3. Thread safety violations - Unsafe ref/deref across threads
**Implementation**
When enabled, RefCountDebugger adds two tracking flags:
- m_deletionHasBegun - Set when destructor starts
- m_adoptionIsRequired - Cleared when adoptRef() is called
These flags are checked on every ref()/deref() call, with assertions
failing on violations.
**Motivation**
Refactored debug code into a separate RefCountDebugger class to:
- Improve readability of core refcount logic
- Eliminate duplicate code across RefCounted, ThreadSafeRefCounted, etc.
- Simplify adding new refcount classes
**Overhead**
Zero in release builds - the flags and checks are compiled out entirely.
### How did you verify your code works?
---------
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
## Summary
- Remove sccache support entirely, use ccache only
- Missing ccache no longer fails the build (just skips caching)
- Remove S3 distributed cache support
## Changes
- Remove `cmake/tools/SetupSccache.cmake` and S3 distributed cache
support
- Simplify `CMakeLists.txt` to only use ccache
- Update `SetupCcache.cmake` to not fail when ccache is missing
- Replace sccache with ccache in bootstrap scripts (sh, ps1)
- Update `.buildkite/Dockerfile` to install ccache instead of sccache
- Update `flake.nix` and `shell.nix` to use ccache
- Update documentation (CONTRIBUTING.md, contributing.mdx,
building-windows.mdx)
- Remove `scripts/build-cache/` directory (was only for sccache S3
access)
## Test plan
- [x] Build completes successfully with `bun bd`
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
- WTFMove → WTF::move / std::move: Replaced WTFMove() macro with
WTF::move() function for WTF types, std::move() for std types
- SortedArrayMap removed: Replaced with if-else chains in
EventFactory.cpp, JSCryptoKeyUsage.cpp
- Wasm::Memory::create signature changed: Removed VM parameter
- URLPattern allocation: Changed from WTF_MAKE_ISO_ALLOCATED to
WTF_MAKE_TZONE_ALLOCATED
---------
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
## Summary
- Add `bun_version` field to `link-metadata.json`
- Pass `VERSION` CMake variable to the metadata script as `BUN_VERSION`
env var
This ensures the build version is captured in the link metadata JSON
file, which is useful for tracking which version produced a given build
artifact.
## Test plan
- Build with `bun bd` and verify `link-metadata.json` includes
`bun_version`
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-authored-by: Claude <noreply@anthropic.com>
## Summary
Fixes#24593 - WebSocket segfault on Windows when publishing large
messages with `perMessageDeflate: true`.
Also fixes#21028 (duplicate issue).
Also closes#25457 (alternative PR).
**Root cause:**
On Windows, the C++ code was compiled against system zlib headers
(1.3.1) but linked against Bun's vendored Cloudflare zlib (1.2.8).
This version mismatch caused `deflateInit2()` to return
`Z_VERSION_ERROR` (-6), leaving the deflate stream in an invalid state.
All subsequent `deflate()` calls returned `Z_STREAM_ERROR` (-2),
producing zero output, which then caused an integer underflow when
subtracting the 4-byte trailer → segfault in memcpy.
**Fix:**
Add `${VENDOR_PATH}/zlib` to the C++ include paths in
`cmake/targets/BuildBun.cmake`. This ensures the vendored zlib headers
are found before system headers, maintaining header/library version
consistency.
This is a simpler alternative to #25457 which worked around the issue by
using libdeflate exclusively.
## Test plan
- [x] Added regression test `test/regression/issue/24593.test.ts` with 4
test cases:
- Large ~109KB JSON message publish (core reproduction)
- Multiple rapid publishes (buffer corruption)
- Broadcast to multiple subscribers
- Messages at CORK_BUFFER_SIZE boundary (16KB)
- [x] Tests pass on Windows (was crashing before fix)
- [x] Tests pass on macOS
🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
### What does this PR do?
Adds [@mschwarzl's Fuzzilli Support
PR](https://github.com/oven-sh/bun/pull/23862) with the changes
necessary to be able to:
- Run it in CI
- Make no impact on `debug` and `release` mode.
### How did you verify your code works?
---------
Co-authored-by: Martin Schwarzl <mschwarzl@cloudflare.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Dylan Conway <dylan.conway567@gmail.com>
Fixes ENG-21481
Updates ci_info to include more CIs. It makes it codegen the ci
detection based on the json from the ci-info package. Also it supports
setting CI=true to force ci detected.
---------
Co-authored-by: pfg <pfg@pfg.pw>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
### What does this PR do?
msvc doesn't support c23 yet
### How did you verify your code works?
---------
Co-authored-by: Marko Vejnovic <marko@bun.com>
