Eliminate `typedef`s when lowering to GLSL

GLSL doesn't support `typedef` declarations.

The lowering code already lowered any named types (references to `typedef`s) to their underlying definition when targetting GLSL.
This changes makes sure that we also don't generate any lowered output for `typedef` declarations in the source program.

1 files changed, 6 insertions, 0 deletions

diff --git a/source/slang/lower.cpp b/source/slang/lower.cpp
index 8bc9619f3..b90573495 100644
--- a/source/slang/lower.cpp
+++ b/source/slang/lower.cpp
@@ -1059,6 +1059,12 @@ struct LoweringVisitor
 
     RefPtr<Decl> visitTypeDefDecl(TypeDefDecl* decl)
     {
+        if (shared->target == CodeGenTarget::GLSL)
+        {
+            // GLSL does not support `typedef`, so we will lower it out of existence here
+            return nullptr;
+        }
+
         RefPtr<TypeDefDecl> loweredDecl = new TypeDefDecl();
         lowerDeclCommon(loweredDecl, decl);