tree 2bd7898c2e1e7256c52380d264a7c711a030a0d3
parent 3d845b5cb05d20c71841efdc9d2d8e3e9bfda796
author rmorisset@apple.com <rmorisset@apple.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc> 1563308761 +0000
committer rmorisset@apple.com <rmorisset@apple.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc> 1563308761 +0000

[WHLSL] Desugar for loops and while loops
https://bugs.webkit.org/show_bug.cgi?id=199726

Reviewed by Myles C. Maxfield.

Source/WebCore:

This patch makes loops behave a lot more similarly to the spec.
In particular, while loops are just degenerate for loops, so they can be desugared in the parser.
And for loops can themselves be heavily desugared, into having no initializer, one condition and one increment
by putting any initializer in a block around the loop, putting true in the condition if there is none, and putting any litteral in the increment if there is none.

Debugging this patch revealed an unrelated bug where the parser would generate an empty comma expression on ";", which the checker would then choke on.
The parser now generates an empty block in that case (as specified in the spec), which fixes the problem.

Finally, while updating the NameResolver for the new structure of loops I realized that it was needlessly generating extra NameContext.
They are not expected by the spec, that forbids naked variable declarations outside of blocks anyway.
So I removed this unnecessary work, and fixed the parser to correctly forbid such naked variable declarations.

* Modules/webgpu/WHLSL/AST/WHLSLAST.h:
* Modules/webgpu/WHLSL/AST/WHLSLForLoop.h:
(WebCore::WHLSL::AST::ForLoop::ForLoop):
(WebCore::WHLSL::AST::ForLoop::condition):
(WebCore::WHLSL::AST::ForLoop::increment):
* Modules/webgpu/WHLSL/AST/WHLSLStatement.h:
(WebCore::WHLSL::AST::Statement::isVariableDeclarationsStatement const):
* Modules/webgpu/WHLSL/AST/WHLSLWhileLoop.h: Removed.
* Modules/webgpu/WHLSL/Metal/WHLSLFunctionWriter.cpp:
(WebCore::WHLSL::Metal::FunctionDefinitionWriter::visit):
* Modules/webgpu/WHLSL/WHLSLASTDumper.cpp:
(WebCore::WHLSL::ASTDumper::visit):
* Modules/webgpu/WHLSL/WHLSLASTDumper.h:
* Modules/webgpu/WHLSL/WHLSLChecker.cpp:
(WebCore::WHLSL::Checker::visit):
* Modules/webgpu/WHLSL/WHLSLNameResolver.cpp:
(WebCore::WHLSL::NameResolver::visit):
* Modules/webgpu/WHLSL/WHLSLNameResolver.h:
* Modules/webgpu/WHLSL/WHLSLParser.cpp:
(WebCore::WHLSL::Parser::parseBlockBody):
(WebCore::WHLSL::Parser::parseForLoop):
(WebCore::WHLSL::Parser::parseWhileLoop):
(WebCore::WHLSL::Parser::parseStatement):
(WebCore::WHLSL::Parser::parseEffectfulExpression):
* Modules/webgpu/WHLSL/WHLSLParser.h:
* Modules/webgpu/WHLSL/WHLSLStatementBehaviorChecker.cpp:
* Modules/webgpu/WHLSL/WHLSLVisitor.cpp:
(WebCore::WHLSL::Visitor::visit):
* Modules/webgpu/WHLSL/WHLSLVisitor.h:
* WebCore.xcodeproj/project.pbxproj:

LayoutTests:

I added the for-loop tests from Test.mjs (with help from Saam).
I did not add the foo9 and foo10 tests, as they are forbidden by the behavior checker in the C++ implementation (and by the spec).

I also changed one test from whlsl-return-spec-tests.html to assert_fail, because it relied on a lone variable declaration in an if, which is forbidden by the spec.

* webgpu/whlsl-for-loop-expected.txt: Added.
* webgpu/whlsl-for-loop.html: Added.
* webgpu/whlsl-return-spec-tests.html:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@247493 268f45cc-cd09-0410-ab3c-d52691b4dbfc