mirror of
https://github.com/oven-sh/bun
synced 2026-02-02 15:08:46 +00:00
05d0475c6c
Fixes ENG-21287
Build times, from `bun run build && echo '//' >> src/main.zig && time
bun run build`
|Platform|0.14.1|0.15.2|Speedup|
|-|-|-|-|
|macos debug asan|126.90s|106.27s|1.19x|
|macos debug noasan|60.62s|50.85s|1.19x|
|linux debug asan|292.77s|241.45s|1.21x|
|linux debug noasan|146.58s|130.94s|1.12x|
|linux debug use_llvm=false|n/a|78.27s|1.87x|
|windows debug asan|177.13s|142.55s|1.24x|
Runtime performance:
- next build memory usage may have gone up by 5%. Otherwise seems the
same. Some code with writers may have gotten slower, especially one
instance of a counting writer and a few instances of unbuffered writers
that now have vtable overhead.
- File size reduced by 800kb (from 100.2mb to 99.4mb)
Improvements:
- `@export` hack is no longer needed for watch
- native x86_64 backend for linux builds faster. to use it, set use_llvm
false and no_link_obj false. also set `ASAN_OPTIONS=detect_leaks=0`
otherwise it will spam the output with tens of thousands of lines of
debug info errors. may need to use the zig lldb fork for debugging.
- zig test-obj, which we will be able to use for zig unit tests
Still an issue:
- false 'dependency loop' errors remain in watch mode
- watch mode crashes observed
Follow-up:
- [ ] search `comptime Writer: type` and `comptime W: type` and remove
- [ ] remove format_mode in our zig fork
- [ ] remove deprecated.zig autoFormatLabelFallback
- [ ] remove deprecated.zig autoFormatLabel
- [ ] remove deprecated.BufferedWriter and BufferedReader
- [ ] remove override_no_export_cpp_apis as it is no longer needed
- [ ] css Parser(W) -> Parser, and remove all the comptime writer: type
params
- [ ] remove deprecated writer fully
Files that add lines:
```
649 src/deprecated.zig
167 scripts/pack-codegen-for-zig-team.ts
54 scripts/cleartrace-impl.js
46 scripts/cleartrace.ts
43 src/windows.zig
18 src/fs.zig
17 src/bun.js/ConsoleObject.zig
16 src/output.zig
12 src/bun.js/test/debug.zig
12 src/bun.js/node/node_fs.zig
8 src/env_loader.zig
7 src/css/printer.zig
7 src/cli/init_command.zig
7 src/bun.js/node.zig
6 src/string/escapeRegExp.zig
6 src/install/PnpmMatcher.zig
5 src/bun.js/webcore/Blob.zig
4 src/crash_handler.zig
4 src/bun.zig
3 src/install/lockfile/bun.lock.zig
3 src/cli/update_interactive_command.zig
3 src/cli/pack_command.zig
3 build.zig
2 src/Progress.zig
2 src/install/lockfile/lockfile_json_stringify_for_debugging.zig
2 src/css/small_list.zig
2 src/bun.js/webcore/prompt.zig
1 test/internal/ban-words.test.ts
1 test/internal/ban-limits.json
1 src/watcher/WatcherTrace.zig
1 src/transpiler.zig
1 src/shell/builtin/cp.zig
1 src/js_printer.zig
1 src/io/PipeReader.zig
1 src/install/bin.zig
1 src/css/selectors/selector.zig
1 src/cli/run_command.zig
1 src/bun.js/RuntimeTranspilerStore.zig
1 src/bun.js/bindings/JSRef.zig
1 src/bake/DevServer.zig
```
Files that remove lines:
```
-1 src/test/recover.zig
-1 src/sql/postgres/SocketMonitor.zig
-1 src/sql/mysql/MySQLRequestQueue.zig
-1 src/sourcemap/CodeCoverage.zig
-1 src/css/values/color_js.zig
-1 src/compile_target.zig
-1 src/bundler/linker_context/convertStmtsForChunk.zig
-1 src/bundler/bundle_v2.zig
-1 src/bun.js/webcore/blob/read_file.zig
-1 src/ast/base.zig
-2 src/sql/postgres/protocol/ArrayList.zig
-2 src/shell/builtin/mkdir.zig
-2 src/install/PackageManager/patchPackage.zig
-2 src/install/PackageManager/PackageManagerDirectories.zig
-2 src/fmt.zig
-2 src/css/declaration.zig
-2 src/css/css_parser.zig
-2 src/collections/baby_list.zig
-2 src/bun.js/bindings/ZigStackFrame.zig
-2 src/ast/E.zig
-3 src/StandaloneModuleGraph.zig
-3 src/deps/picohttp.zig
-3 src/deps/libuv.zig
-3 src/btjs.zig
-4 src/threading/Futex.zig
-4 src/shell/builtin/touch.zig
-4 src/meta.zig
-4 src/install/lockfile.zig
-4 src/css/selectors/parser.zig
-5 src/shell/interpreter.zig
-5 src/css/error.zig
-5 src/bun.js/web_worker.zig
-5 src/bun.js.zig
-6 src/cli/test_command.zig
-6 src/bun.js/VirtualMachine.zig
-6 src/bun.js/uuid.zig
-6 src/bun.js/bindings/JSValue.zig
-9 src/bun.js/test/pretty_format.zig
-9 src/bun.js/api/BunObject.zig
-14 src/install/install_binding.zig
-14 src/fd.zig
-14 src/bun.js/node/path.zig
-14 scripts/pack-codegen-for-zig-team.sh
-17 src/bun.js/test/diff_format.zig
```
`git diff --numstat origin/main...HEAD | awk '{ print ($1-$2)"\t"$3 }' |
sort -rn`
---------
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Dylan Conway <dylan.conway567@gmail.com>
Co-authored-by: Meghan Denny <meghan@bun.com>
Co-authored-by: tayor.fish <contact@taylor.fish>
LLDB Pretty Printers for Bun
This directory contains LLDB pretty printers for various Bun data structures to improve the debugging experience.
Files
bun_pretty_printer.py- Pretty printers for Bun-specific types (bun.String, WTFStringImpl, ZigString, BabyList, etc.)lldb_pretty_printers.py- Pretty printers for Zig language types from the Zig projectlldb_webkit.py- Pretty printers for WebKit/JavaScriptCore typesinit.lldb- LLDB initialization commands
Supported Types
bun.String Types
bun.String(or justString) - The main Bun string typeWTFStringImpl- WebKit string implementation (Latin1/UTF16)ZigString- Zig string type (UTF8/Latin1/UTF16 with pointer tagging)
Display Format
The pretty printers show string content directly, with additional metadata:
# bun.String examples:
"Hello, World!" [latin1] # Regular ZigString
"UTF-8 String 🎉" [utf8] # UTF-8 encoded
"Static content" [latin1 static] # Static string
"" # Empty string
<dead> # Dead/invalid string
# WTFStringImpl examples:
"WebKit String" # Shows the actual string content
# ZigString examples:
"Some text" [utf16 global] # UTF16 globally allocated
"ASCII text" [latin1] # Latin1 encoded
Usage
Option 1: Manual Loading
In your LLDB session:
command script import /path/to/bun/misctools/lldb/bun_pretty_printer.py
Option 2: Add to ~/.lldbinit
Add the following line to your ~/.lldbinit file to load automatically:
command script import /path/to/bun/misctools/lldb/bun_pretty_printer.py
Option 3: Use init.lldb
command source /path/to/bun/misctools/lldb/init.lldb
Testing
To test the pretty printers:
- Build a debug version of Bun:
bun bd
-
Create a test file that uses bun.String types
-
Debug with LLDB:
lldb ./build/debug/bun-debug
(lldb) command script import misctools/lldb/bun_pretty_printer.py
(lldb) breakpoint set --file your_test.zig --line <line_number>
(lldb) run your_test.zig
(lldb) frame variable
Implementation Details
ZigString Pointer Tagging
ZigString uses pointer tagging in the upper bits:
- Bit 63: 1 = UTF16, 0 = UTF8/Latin1
- Bit 62: 1 = Globally allocated (mimalloc)
- Bit 61: 1 = UTF8 encoding
The pretty printer automatically detects and handles these tags.
WTFStringImpl Encoding
WTFStringImpl uses flags in m_hashAndFlags:
- Bit 2 (s_hashFlag8BitBuffer): 1 = Latin1, 0 = UTF16
bun.String Tag Union
bun.String is a tagged union with these variants:
- Dead (0): Invalid/freed string
- WTFStringImpl (1): WebKit string
- ZigString (2): Regular Zig string
- StaticZigString (3): Static/immortal string
- Empty (4): Empty string ""
Troubleshooting
If the pretty printers don't work:
- Verify the Python script loaded:
(lldb) script print("Python works")
- Check if the category is enabled:
(lldb) type category list
- Enable the Bun category manually:
(lldb) type category enable bun
- For debugging the pretty printer itself, check for exceptions:
- The pretty printers catch all exceptions and return
<error> - Modify the code to print exceptions for debugging