luau/CodeGen/include/Luau/CodeAllocator.h
vegorov-rbx 42a2805f85
Sync to upstream/release/568 (#865)
* A small subset of control-flow refinements have been added to
recognize type options that are unreachable after a
conditional/unconditional code block. (Fixes
https://github.com/Roblox/luau/issues/356).

Some examples:
```lua
local function f(x: string?)
    if not x then return end

    -- x is 'string' here
end
```
Throwing calls like `error` or `assert(false)` instead of 'return' are
also recognized.
Existing complex refinements like type/typeof and tagged union checks
are expected to work, among others.

To enable this feature, `LuauTinyControlFlowAnalysis` exclusion has to
be removed from `ExperimentalFlags.h`.
If will become enabled unconditionally in the near future.

* Linter has been integrated into the typechecker analysis so that
type-aware lint warnings can work in any mode
`Frontend::lint` methods were deprecated, `Frontend::check` has to be
used instead with `runLintChecks` option set.
Resulting lint warning are located inside `CheckResult`.

* Fixed large performance drop and increased memory consumption when
array is filled at an offset (Fixes
https://github.com/Roblox/luau/issues/590)
* Part of [Type error suppression
RFC](https://github.com/Roblox/luau/blob/master/rfcs/type-error-suppression.md)
was implemented making subtyping checks with `any` type transitive.

---
In our work on the new type-solver:
* `--!nocheck` mode no longer reports type errors
* New solver will not be used for `--!nonstrict` modules until all
issues with strict mode typechecking are fixed
* Added control-flow aware type refinements mentioned earlier

In native code generation:
* `LOP_NAMECALL` has been translated to IR
* `type` and `typeof` builtin fastcalls have been translated to
IR/assembly
* Additional steps were taken towards arm64 support
2023-03-17 12:20:37 -07:00

57 lines
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C++

// This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
#pragma once
#include <vector>
#include <stddef.h>
#include <stdint.h>
namespace Luau
{
namespace CodeGen
{
constexpr uint32_t kCodeAlignment = 32;
struct CodeAllocator
{
CodeAllocator(size_t blockSize, size_t maxTotalSize);
~CodeAllocator();
// Places data and code into the executable page area
// To allow allocation while previously allocated code is already running, allocation has page granularity
// It's important to group functions together so that page alignment won't result in a lot of wasted space
bool allocate(
const uint8_t* data, size_t dataSize, const uint8_t* code, size_t codeSize, uint8_t*& result, size_t& resultSize, uint8_t*& resultCodeStart);
// Provided to callbacks
void* context = nullptr;
// Called when new block is created to create and setup the unwinding information for all the code in the block
// 'startOffset' reserves space for data at the beginning of the page
void* (*createBlockUnwindInfo)(void* context, uint8_t* block, size_t blockSize, size_t& startOffset) = nullptr;
// Called to destroy unwinding information returned by 'createBlockUnwindInfo'
void (*destroyBlockUnwindInfo)(void* context, void* unwindData) = nullptr;
// Unwind information can be placed inside the block with some implementation-specific reservations at the beginning
// But to simplify block space checks, we limit the max size of all that data
static const size_t kMaxReservedDataSize = 256;
bool allocateNewBlock(size_t& unwindInfoSize);
// Current block we use for allocations
uint8_t* blockPos = nullptr;
uint8_t* blockEnd = nullptr;
// All allocated blocks
std::vector<uint8_t*> blocks;
std::vector<void*> unwindInfos;
size_t blockSize = 0;
size_t maxTotalSize = 0;
};
} // namespace CodeGen
} // namespace Luau