blob: 25057e09a2f31199858286b2f62d106d3e0265ed [file] [log] [blame]
// Copyright (c) 2019, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
#include "vm/ffi_callback_trampolines.h"
#if !defined(DART_PRECOMPILED_RUNTIME)
#include "vm/code_comments.h"
#include "vm/code_observers.h"
#include "vm/compiler/assembler/assembler.h"
#include "vm/compiler/assembler/disassembler.h"
#include "vm/exceptions.h"
#endif // !defined(DART_PRECOMPILED_RUNTIME)
namespace dart {
DECLARE_FLAG(bool, disassemble_stubs);
#if !defined(DART_PRECOMPILED_RUNTIME)
uword NativeCallbackTrampolines::TrampolineForId(int32_t callback_id) {
#if defined(DART_PRECOMPILER)
ASSERT(!Enabled());
UNREACHABLE();
#else
const intptr_t trampolines_per_page = NumCallbackTrampolinesPerPage();
const intptr_t page_index = callback_id / trampolines_per_page;
const uword entry_point = trampoline_pages_[page_index]->start();
return entry_point +
(callback_id % trampolines_per_page) *
compiler::StubCodeCompiler::kNativeCallbackTrampolineSize;
#endif
}
void NativeCallbackTrampolines::AllocateTrampoline() {
#if defined(DART_PRECOMPILER)
ASSERT(!Enabled());
UNREACHABLE();
#else
// Callback IDs are limited to 32-bits for trampoline compactness.
if (kWordSize == 8 &&
!Utils::IsInt(32, next_callback_id_ + NumCallbackTrampolinesPerPage())) {
Exceptions::ThrowOOM();
}
if (trampolines_left_on_page_ == 0) {
// Fuchsia requires memory to be allocated with ZX_RIGHT_EXECUTE in order
// to be flipped to kReadExecute after being kReadWrite.
VirtualMemory* const memory = VirtualMemory::AllocateAligned(
/*size=*/VirtualMemory::PageSize(),
/*alignment=*/VirtualMemory::PageSize(),
/*is_executable=*/true, /*name=*/"Dart VM FFI callback trampolines");
memory->Protect(VirtualMemory::kReadWrite);
if (memory == nullptr) {
Exceptions::ThrowOOM();
}
trampoline_pages_.Add(memory);
compiler::Assembler assembler(/*object_pool_builder=*/nullptr);
compiler::StubCodeCompiler::GenerateJITCallbackTrampolines(
&assembler, next_callback_id_);
MemoryRegion region(memory->address(), memory->size());
assembler.FinalizeInstructions(region);
memory->Protect(VirtualMemory::kReadExecute);
#if !defined(PRODUCT)
const char* name = "FfiJitCallbackTrampolines";
ASSERT(!Thread::Current()->IsAtSafepoint());
if (CodeObservers::AreActive()) {
const auto& comments = CreateCommentsFrom(&assembler);
CodeObservers::NotifyAll(name,
/*base=*/memory->start(),
/*prologue_offset=*/0,
/*size=*/assembler.CodeSize(),
/*optimized=*/false, // not really relevant
&comments);
}
#endif
#if !defined(PRODUCT) || defined(FORCE_INCLUDE_DISASSEMBLER)
if (FLAG_disassemble_stubs && FLAG_support_disassembler) {
DisassembleToStdout formatter;
THR_Print(
"Code for native callback trampolines "
"[%" Pd " -> %" Pd "]: {\n",
next_callback_id_,
next_callback_id_ + NumCallbackTrampolinesPerPage() - 1);
const auto& comments = CreateCommentsFrom(&assembler);
Disassembler::Disassemble(memory->start(),
memory->start() + assembler.CodeSize(),
&formatter, &comments);
}
#endif
trampolines_left_on_page_ = NumCallbackTrampolinesPerPage();
}
trampolines_left_on_page_--;
next_callback_id_++;
#endif // defined(DART_PRECOMPILER)
}
#endif // !defined(DART_PRECOMPILED_RUNTIME)
} // namespace dart