[clang] [llvm] Tentative fix for not removing newly internal functions (PR #106146)

[Greg Roth via cfe-commits]

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@@ -18,19 +18,20 @@
 using namespace llvm;
 
 static bool finalizeLinkage(Module &M) {
-  SmallPtrSet<Function *, 8> EntriesAndExports;
+  SmallPtrSet<Function *, 8> Funcs;
 
   // Find all entry points and export functions
   for (Function &EF : M.functions()) {
-    if (!EF.hasFnAttribute("hlsl.shader") && !EF.hasFnAttribute("hlsl.export"))
+    if (EF.hasFnAttribute("hlsl.shader") || EF.hasFnAttribute("hlsl.export"))
       continue;
-    EntriesAndExports.insert(&EF);
+    Funcs.insert(&EF);
   }
 
-  for (Function &F : M.functions()) {
-    if (F.getLinkage() == GlobalValue::ExternalLinkage &&
-        !EntriesAndExports.contains(&F)) {
-      F.setLinkage(GlobalValue::InternalLinkage);
+  for (Function *F : Funcs) {
+    if (F->getLinkage() == GlobalValue::ExternalLinkage) {
+      F->setLinkage(GlobalValue::InternalLinkage);
+      if (F->isDefTriviallyDead())
----------------
pow2clk wrote:

Not sure if this should also check that the alwaysinline attribute is set like AlwaysInliner does: https://github.com/llvm/llvm-project/blob/2a5ac9d9aff91406b0c58629df3a4e4dce87738c/llvm/lib/Transforms/IPO/AlwaysInliner.cpp#L89

We should always inline functions that are marked internal, so I don't know of a case where it wouldn't be set. 

https://github.com/llvm/llvm-project/pull/106146