Files
carbon-lang/toolchain/semantics/node_ref.h
T
Jon Ross-Perkins a23f15e901 Refactoring Semantics towards a more instruction-like model (#1349)
This is how I'm interpreting discussion:

- Basic elements are getting set to an ID.
- SetName exists to assign a name (which can then be referred to later with an identifier expression) to an ID.
- Expressions are broken down into a series of operations which operate on IDs.

So with something like the last test:

```
fn Main() { return 12 + 34; }
```

This becomes:

```
Function(%0,
  {IntegerLiteral(%3, 12),
   IntegerLiteral(%2, 34),
   BinaryOperator(%1, +, %3, %2),
   Return(%1),
  })
SetName(`Main`, %0)
```

Note I'm treating blocks as fairly equal to the top of a file now, and basically eliminating boundaries between things. That's because we have discussed also supporting code like:

```
fn Foo() {
  fn Bar() {}
  Bar();
}
```

Here a declaration of a function is occurring inside a code block, so it felt like eliminating the difference was the best choice.

I know you'd commented on the separation of nodes to individual files before; I still think we're going to have a lot of different types of nodes, and so separating them out into individual files makes them easier to browse.
2022-07-06 11:08:47 -07:00

41 lines
1.1 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_TOOLCHAIN_SEMANTICS_NODE_REF_H_
#define CARBON_TOOLCHAIN_SEMANTICS_NODE_REF_H_
#include <cstdint>
#include "common/ostream.h"
#include "toolchain/semantics/node_kind.h"
namespace Carbon::Semantics {
// The standard structure for nodes.
//
// This flyweight pattern is used so that each subtype can be stored in its own
// vector, minimizing memory consumption and heap fragmentation when large
// quantities are being created.
class NodeRef {
public:
NodeRef() : NodeRef(NodeKind::Invalid, -1) {}
auto kind() -> NodeKind { return kind_; }
private:
template <typename... StoredNodeT>
friend class NodeStoreBase;
NodeRef(NodeKind kind, int32_t index) : kind_(kind), index_(index) {}
NodeKind kind_;
// The index of the named entity within its list.
int32_t index_;
};
} // namespace Carbon::Semantics
#endif // CARBON_TOOLCHAIN_SEMANTICS_NODE_REF_H_