[webkit-changes] [WebKit/WebKit] 1e7620: [WGSL] Add IdentityExpression node

[Tadeu Zagallo]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 1e76207c4357149a69994b53bb756f31996c13df
      https://github.com/WebKit/WebKit/commit/1e76207c4357149a69994b53bb756f31996c13df
  Author: Tadeu Zagallo <tzagallo at apple.com>
  Date:   2023-01-30 (Mon, 30 Jan 2023)

  Changed paths:
    M Source/WebGPU/WGSL/AST/AST.h
    M Source/WebGPU/WGSL/AST/ASTForward.h
    M Source/WebGPU/WGSL/AST/ASTIdentifierExpression.h
    A Source/WebGPU/WGSL/AST/ASTIdentityExpression.h
    M Source/WebGPU/WGSL/AST/ASTNode.h
    M Source/WebGPU/WGSL/AST/ASTVisitor.cpp
    M Source/WebGPU/WGSL/AST/ASTVisitor.h
    M Source/WebGPU/WGSL/GlobalVariableRewriter.cpp
    M Source/WebGPU/WebGPU.xcodeproj/project.pbxproj

  Log Message:
  -----------
  [WGSL] Add IdentityExpression node
https://bugs.webkit.org/show_bug.cgi?id=251262
<rdar://problem/104740808>

Reviewed by Myles C. Maxfield.

Address the FIXME from IdentifierExpression by introducing an IdentityExpression node.
This new node is a special node that does nothing but point to another expression. It's
useful when replacing nodes, if the new node is larger than the existing node. In which
case, an identity node can be used to point to the larger node.

* Source/WebGPU/WGSL/AST/AST.h:
* Source/WebGPU/WGSL/AST/ASTForward.h:
* Source/WebGPU/WGSL/AST/ASTIdentifierExpression.h:
* Source/WebGPU/WGSL/AST/ASTIdentityExpression.h: Copied from Source/WebGPU/WGSL/AST/ASTIdentifierExpression.h.
* Source/WebGPU/WGSL/AST/ASTNode.h:
* Source/WebGPU/WGSL/AST/ASTVisitor.cpp:
(WGSL::AST::Visitor::visit):
* Source/WebGPU/WGSL/AST/ASTVisitor.h:
* Source/WebGPU/WGSL/GlobalVariableRewriter.cpp:
(WGSL::replace):
(WGSL::RewriteGlobalVariables::visit):
* Source/WebGPU/WebGPU.xcodeproj/project.pbxproj:

Canonical link: https://commits.webkit.org/259552@main