Branch: refs/heads/main
Home: https://github.com/WebKit/WebKit
Commit: 29ac32293df6aedf716001999056f180b7145eaa
https://github.com/WebKit/WebKit/commit/29ac32293df6aedf716001999056f180b7145eaa
Author: Keith Miller <[email protected]>
Date: 2026-05-16 (Sat, 16 May 2026)
Changed paths:
M
Source/JavaScriptCore/SaferCPPExpectations/MemoryUnsafeCastCheckerExpectations
M
Source/JavaScriptCore/SaferCPPExpectations/UncountedCallArgsCheckerExpectations
M
Source/JavaScriptCore/SaferCPPExpectations/UncountedLocalVarsCheckerExpectations
M Source/JavaScriptCore/runtime/NativeCallee.h
M Source/JavaScriptCore/wasm/WasmCalleeGroup.cpp
M Source/JavaScriptCore/wasm/WasmCalleeGroup.h
M Source/JavaScriptCore/wasm/WasmConstExprGenerator.cpp
M Source/JavaScriptCore/wasm/WasmFunctionParser.h
M Source/JavaScriptCore/wasm/WasmIPIntPlan.cpp
M Source/JavaScriptCore/wasm/WasmIPIntPlan.h
M Source/JavaScriptCore/wasm/WasmModuleInformation.h
M Source/JavaScriptCore/wasm/WasmOperationsInlines.h
M Source/JavaScriptCore/wasm/WasmSectionParser.cpp
M Source/JavaScriptCore/wasm/js/JSWebAssemblyInstance.cpp
M Source/JavaScriptCore/wasm/js/JSWebAssemblyInstance.h
M Source/JavaScriptCore/wasm/js/WebAssemblyFunction.cpp
M Source/JavaScriptCore/wasm/js/WebAssemblyFunction.h
M Source/JavaScriptCore/wasm/js/WebAssemblyModuleRecord.cpp
Log Message:
-----------
[Wasm] Build JS Wrappers and JSToWasmCallees Lazily
https://bugs.webkit.org/show_bug.cgi?id=314910
rdar://177187656
Reviewed by Yusuke Suzuki.
Wasm instantiation eagerly built two things that are commonly unused:
1. A WebAssemblyFunction (or WebAssemblyWrapperFunction) wrapper for every
function listed in ModuleInformation::referencedFunctions() — the union of
exports, ref.func targets, and element-segment entries. Many modules never
expose most of those functions to JS.
2. A Wasm::JSToWasmCallee for every defined Wasm function, built inside
IPIntPlan and stored in CalleeGroup::m_jsToWasmCallees. Most internal
functions are never called from JS, so the thunk and frame-size
computation were wasted.
This patch makes both lazy. The resulting eagerness matrix is:
| Function kind | Wrapper | JS->Wasm
callee |
|------------------------------------|------------------------------|-----------------|
| Exported | eager (instantiation) |
eager-on-create |
| In an active element segment | eager (table-init at link) |
eager-on-create |
| Only via passive/dec element seg | lazy (table.init/table.copy) |
eager-on-create |
| Only via ref.func | lazy (ref.func execution) |
eager-on-create |
| Host import | lazy | n/a
|
Wrappers for non-exports are now materialized on demand by the new
JSWebAssemblyInstance::ensureFunctionWrapper(FunctionSpaceIndex), which
folds in the previous makeFunctionWrapper lambda from
WebAssemblyModuleRecord. The eager loop over referencedFunctions() is
replaced with a smaller exports-only loop in WebAssemblyModuleRecord.
Active element segments still create wrappers at instantiation, but only
for the functions they actually contain (via the table-init code path),
not the precomputed union of all referenced functions. ref.func, table
init/copy, const-expr evaluation, and the start-function path all now
route through ensureFunctionWrapper.
JSToWasmCallee construction is removed from IPIntPlan
(takeJSToWasmCallees, ensureEntrypoint, m_entrypoints, m_jsToWasmCallees
are gone). CalleeGroup::ensureJSToWasmCallee(const ModuleInformation&,
FunctionSpaceIndex) creates and caches the JSToWasmCallee on first
demand, guarded by a dedicated m_jsToWasmCalleesLock so it does not
contend with the rest of CalleeGroup::m_lock. WebAssemblyFunction owns a
RefPtr to the boxed callee and exposes ensureJSToWasmCallee, which is
called from WebAssemblyFunction::create so the LLInt and JIT JS->Wasm
entry trampolines (which read m_boxedJSToWasmCallee and m_frameSize
directly via fixed offsets, bypassing callWebAssemblyFunction) always
observe a populated value. WebAssemblyFunction is single-threaded so no
extra locking is needed there.
Also, remove the ModuleInformation::referencedFunctions() function and
related BitVector. The referencedFunctions list was only used to
determine which functions to create wrappers for.
No new tests, no behavior change. Covered by existing tests.
Canonical link: https://commits.webkit.org/313362@main
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