[clang] [CIR][HIP] Match kernel handle linkage, visibility and comdat (PR #227267)

[Steffen Larsen via cfe-commits]

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@@ -417,6 +424,13 @@ mlir::Operation *CIRGenNVCUDARuntime::getKernelHandle(cir::FuncOp fn,
   globalOp->setAttr("alignment", builder.getI64IntegerAttr(
                                      cgm.getPointerAlign().getQuantity()));
 
+  // Inherit visibility and comdat from the kernel's declaration.
+  auto *fd = cast<FunctionDecl>(gd.getDecl());
+  cgm.setGVProperties(globalOp, fd);
+  FunctionTemplateDecl *ft = fd->getPrimaryTemplate();
+  if (!ft || ft->isThisDeclarationADefinition())
+    cgm.maybeSetTrivialComdat(*fd, globalOp);
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steffenlarsen wrote:

At this point comdat hasn't been finalized yet, so `getComdat` would not not reflect it correctly. If we wanted to do it by copying through `getComdat` we could move it back to `emitDeviceStub`, but the current implementation is based off of OGCG and should result in correct comdat being produced for the handle.

https://github.com/llvm/llvm-project/pull/227267