Fix GLSL global const diagnostic regression (#7808)

* Initial plan

* Fix GLSL global const diagnostic regression - add test exclusion for GLSL module

Co-authored-by: csyonghe <2652293+csyonghe@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>

1 files changed, 10 insertions, 4 deletions

diff --git a/source/slang/slang-check-decl.cpp b/source/slang/slang-check-decl.cpp
index 46876131a..1dc230dae 100644
--- a/source/slang/slang-check-decl.cpp
+++ b/source/slang/slang-check-decl.cpp
@@ -240,13 +240,19 @@ struct SemanticsDeclModifiersVisitor : public SemanticsDeclVisitorBase,
         // In HLSL, const global variables without static are uniform parameters
         // that cannot have default values
         // Exception: specialization constants are allowed to have initializers
+        // Exception: In GLSL mode, global const variables are real constants, not uniform
+        // parameters
         if (isGlobalDecl(decl) && (hasConst || hasUniform) && !hasStatic &&
             !hasSpecializationConstant && decl->initExpr)
         {
-            getSink()->diagnose(
-                decl,
-                Diagnostics::constGlobalVarWithInitRequiresStatic,
-                decl->getName());
+            auto moduleDecl = getModuleDecl(decl);
+            if (!moduleDecl || !moduleDecl->hasModifier<GLSLModuleModifier>())
+            {
+                getSink()->diagnose(
+                    decl,
+                    Diagnostics::constGlobalVarWithInitRequiresStatic,
+                    decl->getName());
+            }
         }
     }