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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=8 sts=2 et sw=2 tw=80:
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "jit/Linker.h"
#include "gc/GC.h"
#include "jit/JitZone.h"
#include "util/Memory.h"
#include "gc/StoreBuffer-inl.h"
namespace js {
namespace jit {
JitCode* Linker::newCode(JSContext* cx, CodeKind kind) {
JS::AutoAssertNoGC nogc(cx);
if (masm.oom()) {
return fail(cx);
}
static const size_t ExecutableAllocatorAlignment = sizeof(void*);
static_assert(CodeAlignment >= ExecutableAllocatorAlignment,
"Unexpected alignment requirements");
// We require enough bytes for the code, header, and worst-case alignment
// padding.
size_t bytesNeeded = masm.bytesNeeded() + sizeof(JitCodeHeader) +
(CodeAlignment - ExecutableAllocatorAlignment);
if (bytesNeeded >= MAX_BUFFER_SIZE) {
return fail(cx);
}
// ExecutableAllocator requires bytesNeeded to be aligned.
bytesNeeded = AlignBytes(bytesNeeded, ExecutableAllocatorAlignment);
JitZone* jitZone = cx->zone()->getJitZone(cx);
if (!jitZone) {
// Note: don't call fail(cx) here, getJitZone reports OOM.
return nullptr;
}
ExecutablePool* pool;
uint8_t* result =
(uint8_t*)jitZone->execAlloc().alloc(cx, bytesNeeded, &pool, kind);
if (!result) {
return fail(cx);
}
// The JitCodeHeader will be stored right before the code buffer.
uint8_t* codeStart = result + sizeof(JitCodeHeader);
// Bump the code up to a nice alignment.
codeStart = (uint8_t*)AlignBytes((uintptr_t)codeStart, CodeAlignment);
MOZ_ASSERT(codeStart + masm.bytesNeeded() <= result + bytesNeeded);
uint32_t headerSize = codeStart - result;
JitCode* code =
JitCode::New<NoGC>(cx, codeStart, bytesNeeded, headerSize, pool, kind);
if (!code) {
return fail(cx);
}
if (masm.oom()) {
return fail(cx);
}
awjcf.emplace(result, bytesNeeded);
if (!awjcf->makeWritable()) {
return fail(cx);
}
code->copyFrom(masm);
masm.link(code);
if (masm.embedsNurseryPointers()) {
cx->runtime()->gc.storeBuffer().putWholeCell(code);
}
return code;
}
} // namespace jit
} // namespace js
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