fix ast-lowering of TransitiveSubtypeWitness values.

csyonghe · csyonghe · commit fd0b8ca60e62 · 2017-12-26T20:20:54.000-05:00
diff --git a/source/slang/ast-legalize.cpp b/source/slang/ast-legalize.cpp
@@ -2623,6 +2623,9 @@ struct LoweringVisitor
         if (auto litVal = dynamic_cast<ConstantIntVal*>(val))
             return val;
 
+        // We do not use subtype witness for ast lowering, return it unchanged.
+        if (auto subtypeWitnessVal = dynamic_cast<SubtypeWitness*>(val))
+            return val;
         SLANG_UNEXPECTED("unhandled value kind");
     }
 

Original file line number	Diff line number	Diff line change
`@@ -2623,6 +2623,9 @@ struct LoweringVisitor`
`2623`	`2623`	`if (auto litVal = dynamic_cast<ConstantIntVal*>(val))`
`2624`	`2624`	`return val;`
`2625`	`2625`
	`2626`	`+ // We do not use subtype witness for ast lowering, return it unchanged.`
	`2627`	`+ if (auto subtypeWitnessVal = dynamic_cast<SubtypeWitness*>(val))`
	`2628`	`+ return val;`
`2626`	`2629`	`SLANG_UNEXPECTED("unhandled value kind");`
`2627`	`2630`	`}`
`2628`	`2631`