luau/CodeGen/src/CodeBlockUnwind.cpp
Andy Friesen 54324867df
Sync to upstream/release/550 (#723)
* Support `["prop"]` syntax on class definitions in definition files.
(#704)
* Improve type checking performance for complex overloaded functions
* Fix rare cases of incorrect stack traces for out of memory errors at
runtime
2022-10-21 10:54:01 -07:00

125 lines
3.6 KiB
C++

// This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
#include "Luau/CodeBlockUnwind.h"
#include "Luau/CodeAllocator.h"
#include "Luau/UnwindBuilder.h"
#include <string.h>
#if defined(_WIN32) && defined(_M_X64)
#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif
#ifndef NOMINMAX
#define NOMINMAX
#endif
#include <Windows.h>
#elif !defined(_WIN32)
// Defined in unwind.h which may not be easily discoverable on various platforms
extern "C" void __register_frame(const void*);
extern "C" void __deregister_frame(const void*);
#endif
#if defined(__APPLE__)
// On Mac, each FDE inside eh_frame section has to be handled separately
static void visitFdeEntries(char* pos, void (*cb)(const void*))
{
for (;;)
{
unsigned partLength;
memcpy(&partLength, pos, sizeof(partLength));
if (partLength == 0) // Zero-length section signals completion
break;
unsigned partId;
memcpy(&partId, pos + 4, sizeof(partId));
if (partId != 0) // Skip CIE part
cb(pos); // CIE is found using an offset in FDE
pos += partLength + 4;
}
}
#endif
namespace Luau
{
namespace CodeGen
{
void* createBlockUnwindInfo(void* context, uint8_t* block, size_t blockSize, size_t& beginOffset)
{
#if defined(_WIN32) && defined(_M_X64)
UnwindBuilder* unwind = (UnwindBuilder*)context;
// All unwinding related data is placed together at the start of the block
size_t unwindSize = sizeof(RUNTIME_FUNCTION) + unwind->getSize();
unwindSize = (unwindSize + (kCodeAlignment - 1)) & ~(kCodeAlignment - 1); // Match code allocator alignment
LUAU_ASSERT(blockSize >= unwindSize);
RUNTIME_FUNCTION* runtimeFunc = (RUNTIME_FUNCTION*)block;
runtimeFunc->BeginAddress = DWORD(unwindSize); // Code will start after the unwind info
runtimeFunc->EndAddress = DWORD(blockSize); // Whole block is a part of a 'single function'
runtimeFunc->UnwindInfoAddress = DWORD(sizeof(RUNTIME_FUNCTION)); // Unwind info is placed at the start of the block
char* unwindData = (char*)block + runtimeFunc->UnwindInfoAddress;
unwind->finalize(unwindData, block + unwindSize, blockSize - unwindSize);
if (!RtlAddFunctionTable(runtimeFunc, 1, uintptr_t(block)))
{
LUAU_ASSERT(!"failed to allocate function table");
return nullptr;
}
beginOffset = unwindSize + unwind->getBeginOffset();
return block;
#elif !defined(_WIN32)
UnwindBuilder* unwind = (UnwindBuilder*)context;
// All unwinding related data is placed together at the start of the block
size_t unwindSize = unwind->getSize();
unwindSize = (unwindSize + (kCodeAlignment - 1)) & ~(kCodeAlignment - 1); // Match code allocator alignment
LUAU_ASSERT(blockSize >= unwindSize);
char* unwindData = (char*)block;
unwind->finalize(unwindData, block, blockSize);
#if defined(__APPLE__)
visitFdeEntries(unwindData, __register_frame);
#else
__register_frame(unwindData);
#endif
beginOffset = unwindSize + unwind->getBeginOffset();
return block;
#endif
return nullptr;
}
void destroyBlockUnwindInfo(void* context, void* unwindData)
{
#if defined(_WIN32) && defined(_M_X64)
RUNTIME_FUNCTION* runtimeFunc = (RUNTIME_FUNCTION*)unwindData;
if (!RtlDeleteFunctionTable(runtimeFunc))
LUAU_ASSERT(!"failed to deallocate function table");
#elif !defined(_WIN32)
#if defined(__APPLE__)
visitFdeEntries((char*)unwindData, __deregister_frame);
#else
__deregister_frame(unwindData);
#endif
#endif
}
} // namespace CodeGen
} // namespace Luau