tree 8d3bbd2e80341aeaeb95605d43f091aa064175b1
parent 5f8061bd39bd2a13980584f7a1f96723458df994
author Ben Clayton <bclayton@google.com> 1607019039 +0000
committer Commit Bot service account <commit-bot@chromium.org> 1607019039 +0000

Add ast::CloneContext::ReplaceAll()

ReplaceAll() registers `replacer` to be called whenever the Clone() method is called with a type that matches (or derives from) the type of the first parameter of `replacer`.

`replacer` must be function-like with the signature: `T* (T*)`, where `T` is a type deriving from CastableBase.

If `replacer` returns a nullptr then Clone() will attempt the next registered replacer function that matches the object type. If no replacers match the object type, or all returned nullptr then Clone() will call `T::Clone()` to clone the object.

Example:

```
  // Replace all ast::UintLiterals with the number 42
  CloneCtx ctx(mod);
  ctx.ReplaceAll([&] (ast::UintLiteral* in) {
    return ctx.mod->create<ast::UintLiteral>(ctx.Clone(in->type()), 42);
  });
  auto* out = ctx.Clone(tree);
```

This is to be used by Transforms that want to replace parts of the AST on clone.

Bug: tint:390
Change-Id: I80a0e58aa3711f309f58a504f6b6a06f6c546ea1
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/34568
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: dan sinclair <dsinclair@chromium.org>