Replace [KnownBuiltin] string-based comparisons with enum-based system (#7714)

* Initial plan

* Implement enum-based KnownBuiltin system to replace string comparisons

Co-authored-by: csyonghe <2652293+csyonghe@users.noreply.github.com>

* Add test for enum-based KnownBuiltin system and verify functionality

Co-authored-by: csyonghe <2652293+csyonghe@users.noreply.github.com>

* Implement enum-based KnownBuiltin system with direct integer values

Co-authored-by: csyonghe <2652293+csyonghe@users.noreply.github.com>

* Fix IntVal access and update tests for new enum-based KnownBuiltin system

Co-authored-by: csyonghe <2652293+csyonghe@users.noreply.github.com>

* Replace hardcoded KnownBuiltin integers with preprocessor enum syntax

- Updated all KnownBuiltin attributes to use $( (int)KnownBuiltinDeclName::EnumValue) syntax
- Added space between parentheses to avoid preprocessor bug: $( (int) instead of $((int)
- Updated both core.meta.slang and hlsl.meta.slang files
- Eliminates preprocessor-time integer conversion, baking enum values directly into meta files
- Maintains same functionality while using type-safe enum references

Co-authored-by: csyonghe <2652293+csyonghe@users.noreply.github.com>

* Fix IDifferentiablePtr KnownBuiltin mapping regression

Co-authored-by: csyonghe <2652293+csyonghe@users.noreply.github.com>

* Remove unused IDifferentiablePtrType enum case from KnownBuiltinDeclName

Co-authored-by: csyonghe <2652293+csyonghe@users.noreply.github.com>

* Clean up temporary AST dump files from testing

Co-authored-by: csyonghe <2652293+csyonghe@users.noreply.github.com>

* Replace hardcoded integer with descriptive constant in KnownBuiltin test

Replace the hardcoded [KnownBuiltin(0)] with a descriptive named constant
GEOMETRY_STREAM_APPEND_BUILTIN to improve code readability and maintainability.
The test now clearly indicates which builtin enum value is being tested.

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Co-authored-by: Gangzheng Tong <gtong-nv@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: csyonghe <2652293+csyonghe@users.noreply.github.com>
Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: Gangzheng Tong <gtong-nv@users.noreply.github.com>
Co-authored-by: Gangzheng Tong <tonggangzheng@gmail.com>

1 files changed, 6 insertions, 3 deletions

diff --git a/source/slang/slang-lower-to-ir.cpp b/source/slang/slang-lower-to-ir.cpp
index ed4336ff9..4b232e829 100644
--- a/source/slang/slang-lower-to-ir.cpp
+++ b/source/slang/slang-lower-to-ir.cpp
@@ -1444,9 +1444,12 @@ static void addLinkageDecoration(
             // We add this to the internal instruction, like other name-like
             // decorations, for instance "nameHint". This prevents it becoming
             // lost during specialization.
-            builder->addKnownBuiltinDecoration(
-                inInst,
-                knownBuiltinModifier->name.getUnownedSlice());
+            auto constantIntVal = as<ConstantIntVal>(knownBuiltinModifier->name);
+            if (constantIntVal)
+            {
+                auto enumValue = constantIntVal->getValue();
+                builder->addKnownBuiltinDecoration(inInst, KnownBuiltinDeclName(enumValue));
+            }
         }
     }
     if (as<InterfaceDecl>(decl->parentDecl) &&