mirror of
https://github.com/carbon-language/carbon-lang.git
synced 2026-10-03 15:16:08 +01:00
Adrien Leravat
d02366f881
Prevent copies when initializing value expression from reference expression. This is based on https://github.com/carbon-language/carbon-lang/pull/2006, which introduces expression categories, and how it is possible to convert to/from those different categories. Continuation of https://github.com/carbon-language/carbon-lang/pull/2907 ## Functional changes * Initializing a value expression from a reference expression takes its value without a copy * Reading from the value expression causes an error if the value changed from the time it was initialized * In this situation, prevents a copy both for variable definitions, and call parameter bindings ## Main implementation changes * Add new `ExpressionCategoryAction`, which evaluates an expression and returns an `ExpressionValue` containing its category and address (if any), in addition to the resulting `Value*` * `ExpressionAction`s now invokes `ExpressionCategoryAction` and unwraps the returned `ExpressionValue` * `RuntimeScope::BindAndPin` method, and corresponding when attempting to read a `value_node`. ## Next work * Avoid unnecessary copies from value expression to value expression, after ensuring that even value expression temporaries are registered for destruction (https://github.com/Pixep/carbon-lang/pull/9)
62 lines
2.3 KiB
C++
62 lines
2.3 KiB
C++
// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
|
|
// Exceptions. See /LICENSE for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
|
|
#ifndef CARBON_EXPLORER_INTERPRETER_HEAP_ALLOCATION_INTERFACE_H_
|
|
#define CARBON_EXPLORER_INTERPRETER_HEAP_ALLOCATION_INTERFACE_H_
|
|
|
|
#include "common/error.h"
|
|
#include "explorer/ast/address.h"
|
|
#include "explorer/ast/value_node.h"
|
|
#include "explorer/common/arena.h"
|
|
#include "explorer/common/nonnull.h"
|
|
#include "explorer/common/source_location.h"
|
|
|
|
namespace Carbon {
|
|
|
|
class Value;
|
|
|
|
// The allocation interface for Heap, factored out as an interface in order to
|
|
// resolve a layering issue. No other class should derive from this.
|
|
class HeapAllocationInterface {
|
|
public:
|
|
HeapAllocationInterface(const HeapAllocationInterface&) = delete;
|
|
auto operator=(const HeapAllocationInterface&)
|
|
-> HeapAllocationInterface& = delete;
|
|
|
|
// Returns the value at the given address in the heap after
|
|
// checking that it is alive.
|
|
virtual auto Read(const Address& a, SourceLocation source_loc) const
|
|
-> ErrorOr<Nonnull<const Value*>> = 0;
|
|
|
|
// Writes the given value at the address in the heap after
|
|
// checking that the address is alive.
|
|
virtual auto Write(const Address& a, Nonnull<const Value*> v,
|
|
SourceLocation source_loc) -> ErrorOr<Success> = 0;
|
|
|
|
// Put the given value on the heap and mark it as alive.
|
|
virtual auto AllocateValue(Nonnull<const Value*> v) -> AllocationId = 0;
|
|
|
|
// Marks this allocation, and all of its sub-objects, as dead.
|
|
virtual auto Deallocate(AllocationId allocation) -> ErrorOr<Success> = 0;
|
|
|
|
// Returns the arena used to allocate the values in this heap.
|
|
virtual auto arena() const -> Arena& = 0;
|
|
|
|
// Binds a value node to a reference, and manages its lifetime.
|
|
virtual void BindValueToReference(const ValueNodeView& node,
|
|
const Address& a) = 0;
|
|
|
|
// Returns whether the value bound at the given node is still alive.
|
|
virtual auto is_bound_value_alive(const ValueNodeView& node,
|
|
const Address& a) const -> bool = 0;
|
|
|
|
protected:
|
|
HeapAllocationInterface() = default;
|
|
virtual ~HeapAllocationInterface() = default;
|
|
};
|
|
|
|
} // namespace Carbon
|
|
|
|
#endif // CARBON_EXPLORER_INTERPRETER_HEAP_ALLOCATION_INTERFACE_H_
|