TokenManager defines Token interfaces for the clang syntax-tree. This is the level
of abstraction that the syntax-tree should use to operate on Tokens.
It decouples the syntax-tree from a particular token implementation (TokenBuffer
previously). This enables us to use a different underlying token implementation
for the syntax Leaf node -- in clang pseudoparser, we want to produce a
syntax-tree with its own pseudo::Token rather than syntax::Token.
Differential Revision: https://reviews.llvm.org/D128411
Rationale:
Children of a syntax tree had forward links only, because there was no
need for reverse links.
This need appeared when we started mutating the syntax tree.
On a forward list, to remove a target node in O(1) we need a pointer to the node before the target. If we don't have this "before" pointer, we have to find it, and that requires O(n).
So in order to remove a syntax node from a tree, we would similarly need to find the node before to then remove. This is both not ergonomic nor does it have a good complexity.
Differential Revision: https://reviews.llvm.org/D90240
Summary:
Copy of https://reviews.llvm.org/D72446, submitting with Ilya's permission.
Only used to assign roles to child nodes for now. This is more efficient
than doing range-based queries.
In the future, will be exposed in the public API of syntax trees.
Reviewers: gribozavr2
Reviewed By: gribozavr2
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D76355
Add checks for some structural invariants when building and mutating
the syntax trees.
Fix a bug failing the invariants after mutations: the parent of nodes
added into the tree was null.
Summary:
This patch adds facilities to mutate the syntax trees and produce
corresponding text replacements.
The public interface of the syntax library now includes facilities to:
1. perform type-safe modifications of syntax trees,
2. compute textual replacements to apply the modifications,
3. create syntax trees not backed by the source code.
For each of the three, we only add a few example transformations in this
patch to illustrate the idea, support for more kinds of nodes and
transformations will be done in follow-up patches.
The high-level mutation operations are implemented on top of operations
that allow to arbitrarily change the trees. They are considered to be
implementation details and are not available to the users of the
library.
Reviewers: sammccall, gribozavr2
Reviewed By: gribozavr2
Subscribers: merge_guards_bot, mgorny, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D64573
Fangrui Song