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.

🤖 Generated with [Claude Code](https://claude.ai/code)

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, 25 insertions, 21 deletions

diff --git a/source/slang/slang-check-expr.cpp b/source/slang/slang-check-expr.cpp
index c7e58a888..9325eda61 100644
--- a/source/slang/slang-check-expr.cpp
+++ b/source/slang/slang-check-expr.cpp
@@ -15,6 +15,7 @@
 #include "slang-ast-decl.h"
 #include "slang-ast-natural-layout.h"
 #include "slang-ast-print.h"
+#include "slang-ast-support-types.h"
 #include "slang-ast-synthesis.h"
 #include "slang-lookup-spirv.h"
 #include "slang-lookup.h"
@@ -4524,29 +4525,32 @@ void SemanticsExprVisitor::maybeCheckKnownBuiltinInvocation(Expr* invokeExpr)
     auto knownBuiltinAttr = callee->findModifier<KnownBuiltinAttribute>();
     if (!knownBuiltinAttr)
         return;
-    if (knownBuiltinAttr->name == "GetAttributeAtVertex")
+    if (auto constantIntVal = as<ConstantIntVal>(knownBuiltinAttr->name))
     {
-        if (checkedInvokeExpr->arguments.getCount() != 2)
-            return;
-        auto vertexAttributeArg = checkedInvokeExpr->arguments[0];
-        auto vertexAttributeArgDeclRefExpr = as<DeclRefExpr>(vertexAttributeArg);
-        if (!vertexAttributeArgDeclRefExpr)
+        if (constantIntVal->getValue() == (int)KnownBuiltinDeclName::GetAttributeAtVertex)
         {
-            getSink()->diagnose(
-                invokeExpr,
-                Diagnostics::getAttributeAtVertexMustReferToPerVertexInput);
-            return;
-        }
-        auto vertexAttributeArgDecl = vertexAttributeArgDeclRefExpr->declRef.getDecl();
-        if (!vertexAttributeArgDecl)
-            return;
-        if (!vertexAttributeArgDecl->findModifier<PerVertexModifier>() &&
-            !vertexAttributeArgDecl->findModifier<HLSLNoInterpolationModifier>())
-        {
-            getSink()->diagnose(
-                vertexAttributeArgDeclRefExpr,
-                Diagnostics::getAttributeAtVertexMustReferToPerVertexInput);
-            return;
+            if (checkedInvokeExpr->arguments.getCount() != 2)
+                return;
+            auto vertexAttributeArg = checkedInvokeExpr->arguments[0];
+            auto vertexAttributeArgDeclRefExpr = as<DeclRefExpr>(vertexAttributeArg);
+            if (!vertexAttributeArgDeclRefExpr)
+            {
+                getSink()->diagnose(
+                    invokeExpr,
+                    Diagnostics::getAttributeAtVertexMustReferToPerVertexInput);
+                return;
+            }
+            auto vertexAttributeArgDecl = vertexAttributeArgDeclRefExpr->declRef.getDecl();
+            if (!vertexAttributeArgDecl)
+                return;
+            if (!vertexAttributeArgDecl->findModifier<PerVertexModifier>() &&
+                !vertexAttributeArgDecl->findModifier<HLSLNoInterpolationModifier>())
+            {
+                getSink()->diagnose(
+                    vertexAttributeArgDeclRefExpr,
+                    Diagnostics::getAttributeAtVertexMustReferToPerVertexInput);
+                return;
+            }
         }
     }
 }