luau/Analysis/src/TypeUtils.cpp
Arseny Kapoulkine 49b0c59eec
Sync to upstream/release/502 (#134)
Changes:
- Support for time tracing for analysis/compiler (not currently exposed
  through CLI)
- Support for type pack arguments in type aliases (#83)
- Basic support for require(path) in luau-analyze
- Add a lint warning for table.move with 0 index as part of
  TableOperation lint
- Remove last STL dependency from Luau.VM
- Minor VS2022 performance tuning

Co-authored-by: Rodactor <rodactor@roblox.com>
2021-11-04 19:34:35 -07:00

79 lines
2.3 KiB
C++

// This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
#include "Luau/TypeUtils.h"
#include "Luau/Scope.h"
#include "Luau/ToString.h"
#include "Luau/TypeInfer.h"
namespace Luau
{
std::optional<TypeId> findMetatableEntry(ErrorVec& errors, const ScopePtr& globalScope, TypeId type, std::string entry, Location location)
{
type = follow(type);
std::optional<TypeId> metatable = getMetatable(type);
if (!metatable)
return std::nullopt;
TypeId unwrapped = follow(*metatable);
if (get<AnyTypeVar>(unwrapped))
return singletonTypes.anyType;
const TableTypeVar* mtt = getTableType(unwrapped);
if (!mtt)
{
errors.push_back(TypeError{location, GenericError{"Metatable was not a table."}});
return std::nullopt;
}
auto it = mtt->props.find(entry);
if (it != mtt->props.end())
return it->second.type;
else
return std::nullopt;
}
std::optional<TypeId> findTablePropertyRespectingMeta(ErrorVec& errors, const ScopePtr& globalScope, TypeId ty, Name name, Location location)
{
if (get<AnyTypeVar>(ty))
return ty;
if (const TableTypeVar* tableType = getTableType(ty))
{
const auto& it = tableType->props.find(name);
if (it != tableType->props.end())
return it->second.type;
}
std::optional<TypeId> mtIndex = findMetatableEntry(errors, globalScope, ty, "__index", location);
while (mtIndex)
{
TypeId index = follow(*mtIndex);
if (const auto& itt = getTableType(index))
{
const auto& fit = itt->props.find(name);
if (fit != itt->props.end())
return fit->second.type;
}
else if (const auto& itf = get<FunctionTypeVar>(index))
{
std::optional<TypeId> r = first(follow(itf->retType));
if (!r)
return singletonTypes.nilType;
else
return *r;
}
else if (get<AnyTypeVar>(index))
return singletonTypes.anyType;
else
errors.push_back(TypeError{location, GenericError{"__index should either be a function or table. Got " + toString(index)}});
mtIndex = findMetatableEntry(errors, globalScope, *mtIndex, "__index", location);
}
return std::nullopt;
}
} // namespace Luau