From ca6242ec4087276809b45060234e0804e7de9abc Mon Sep 17 00:00:00 2001
From: Helena Kotas <hekotas@microsoft.com>
Date: Fri, 7 Jun 2024 12:08:00 -0700
Subject: [PATCH] Set internal linkage on groupshared variables; check if
 function is defined

---
 clang/include/clang/Basic/Attr.td   | 4 +++-
 clang/lib/AST/Decl.cpp              | 6 ++++++
 clang/lib/CodeGen/CGHLSLRuntime.cpp | 8 ++++----
 3 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/clang/include/clang/Basic/Attr.td b/clang/include/clang/Basic/Attr.td
index 17d9a710d948b2..4e292826d4e1a1 100644
--- a/clang/include/clang/Basic/Attr.td
+++ b/clang/include/clang/Basic/Attr.td
@@ -158,8 +158,10 @@ def FunctionTmpl
 
 def HLSLEntry
     : SubsetSubject<Function,
-                    [{S->isExternallyVisible() && !isa<CXXMethodDecl>(S)}],
+                    [{S->getDeclContext()->getRedeclContext()->isFileContext() &&
+                      S->getStorageClass() != SC_Static}],
                     "global functions">;
+                    
 def HLSLBufferObj : SubsetSubject<HLSLBuffer,
                     [{isa<HLSLBufferDecl>(S)}],
                     "cbuffer/tbuffer">;
diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index 1f19dadafa44e8..dc5566bab312cc 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -621,6 +621,7 @@ LinkageComputer::getLVForNamespaceScopeDecl(const NamedDecl *D,
     // - a variable, variable template, function, or function template
     //   that is explicitly declared static; or
     // (This bullet corresponds to C99 6.2.2p3.)
+    // - also applies to HLSL
     return LinkageInfo::internal();
   }
 
@@ -657,6 +658,11 @@ LinkageComputer::getLVForNamespaceScopeDecl(const NamedDecl *D,
       if (PrevVar->getStorageClass() == SC_Static)
         return LinkageInfo::internal();
     }
+
+    if (Context.getLangOpts().HLSL &&
+        Var->hasAttr<HLSLGroupSharedAddressSpaceAttr>())
+      return LinkageInfo::internal();
+
   } else if (const auto *IFD = dyn_cast<IndirectFieldDecl>(D)) {
     //   - a data member of an anonymous union.
     const VarDecl *VD = IFD->getVarDecl();
diff --git a/clang/lib/CodeGen/CGHLSLRuntime.cpp b/clang/lib/CodeGen/CGHLSLRuntime.cpp
index 8e5123daf2084b..173f0c1449c869 100644
--- a/clang/lib/CodeGen/CGHLSLRuntime.cpp
+++ b/clang/lib/CodeGen/CGHLSLRuntime.cpp
@@ -361,10 +361,10 @@ void CGHLSLRuntime::emitFunctionProlog(const FunctionDecl *FD,
   if (FD->hasAttr<HLSLShaderAttr>()) {
     emitEntryFunction(FD, Fn);
   } else {
-    // HLSL functions that are not shader entry points or exported
-    // have internal linkage by default.
-    // FIXME: skip this for exported functions (Issue #92812)
-    Fn->setLinkage(GlobalValue::InternalLinkage);
+    // HLSL functions defined in the current translation unit that are not
+    // shader entry points or exported have internal linkage by default.
+    if (FD->isDefined())
+      Fn->setLinkage(GlobalValue::InternalLinkage);
   }
 }