mirror of
https://github.com/RGBCube/serenity
synced 2025-10-31 02:32:45 +00:00
67 lines
2.1 KiB
C++
67 lines
2.1 KiB
C++
/*
|
|
* Copyright (c) 2021, Andreas Kling <kling@serenityos.org>
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#include <AK/String.h>
|
|
#include <LibJS/Bytecode/BasicBlock.h>
|
|
#include <LibJS/Bytecode/Op.h>
|
|
#include <sys/mman.h>
|
|
|
|
namespace JS::Bytecode {
|
|
|
|
NonnullOwnPtr<BasicBlock> BasicBlock::create(String name, size_t size)
|
|
{
|
|
return adopt_own(*new BasicBlock(move(name), max(size, static_cast<size_t>(4 * KiB))));
|
|
}
|
|
|
|
BasicBlock::BasicBlock(String name, size_t size)
|
|
: m_name(move(name))
|
|
{
|
|
// FIXME: This is not the smartest solution ever. Find something cleverer!
|
|
// The main issue we're working around here is that we don't want pointers into the bytecode stream to become invalidated
|
|
// during code generation due to dynamic buffer resizing. Otherwise we could just use a Vector.
|
|
m_buffer_capacity = size;
|
|
m_buffer = (u8*)mmap(nullptr, m_buffer_capacity, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
|
|
VERIFY(m_buffer != MAP_FAILED);
|
|
}
|
|
|
|
BasicBlock::~BasicBlock()
|
|
{
|
|
Bytecode::InstructionStreamIterator it(instruction_stream());
|
|
while (!it.at_end()) {
|
|
auto& to_destroy = (*it);
|
|
++it;
|
|
Instruction::destroy(const_cast<Instruction&>(to_destroy));
|
|
}
|
|
|
|
munmap(m_buffer, m_buffer_capacity);
|
|
}
|
|
|
|
void BasicBlock::seal()
|
|
{
|
|
// FIXME: mprotect the instruction stream as PROT_READ
|
|
// This is currently not possible because instructions can have destructors (that clean up strings)
|
|
// Instructions should instead be destructor-less and refer to strings in a string table on the Bytecode::Block.
|
|
// It also doesn't work because instructions that have String members use RefPtr internally which must be in writable memory.
|
|
}
|
|
|
|
void BasicBlock::dump(Bytecode::Executable const& executable) const
|
|
{
|
|
Bytecode::InstructionStreamIterator it(instruction_stream());
|
|
if (!m_name.is_empty())
|
|
warnln("{}:", m_name);
|
|
while (!it.at_end()) {
|
|
warnln("[{:4x}] {}", it.offset(), (*it).to_string(executable));
|
|
++it;
|
|
}
|
|
}
|
|
|
|
void BasicBlock::grow(size_t additional_size)
|
|
{
|
|
m_buffer_size += additional_size;
|
|
VERIFY(m_buffer_size <= m_buffer_capacity);
|
|
}
|
|
|
|
}
|