[CIR][CUDA] Add initial support for name-mangling CUDA declarations

Author: AdUhTkJm

clang/lib/CIR/CodeGen/CIRGenModule.cpp

@@ -516,7 +516,6 @@ void CIRGenModule::emitGlobal(GlobalDecl GD) {
 
   assert(!Global->hasAttr<IFuncAttr>() && "NYI");
   assert(!Global->hasAttr<CPUDispatchAttr>() && "NYI");
-  assert(!langOpts.CUDA && "NYI");
 
   if (langOpts.OpenMP) {
     // If this is OpenMP, check if it is legal to emit this global normally.
@@ -559,6 +558,7 @@ void CIRGenModule::emitGlobal(GlobalDecl GD) {
       return;
     }
   } else {
+    assert(!langOpts.CUDA && "NYI");
     const auto *VD = cast<VarDecl>(Global);
     assert(VD->isFileVarDecl() && "Cannot emit local var decl as global.");
     if (VD->isThisDeclarationADefinition() != VarDecl::Definition &&
@@ -2291,7 +2291,7 @@ static std::string getMangledNameImpl(CIRGenModule &CGM, GlobalDecl GD,
       assert(0 && "NYI");
     } else if (FD && FD->hasAttr<CUDAGlobalAttr>() &&
                GD.getKernelReferenceKind() == KernelReferenceKind::Stub) {
-      assert(0 && "NYI");
+      Out << "__device_stub__" << II->getName();
     } else {
       Out << II->getName();
     }
@@ -2309,7 +2309,23 @@ static std::string getMangledNameImpl(CIRGenModule &CGM, GlobalDecl GD,
   if (const auto *FD = dyn_cast<FunctionDecl>(ND)) {
     assert(!FD->isMultiVersion() && "NYI");
   }
-  assert(!CGM.getLangOpts().GPURelocatableDeviceCode && "NYI");
+
+  // we need to generate a unique mangled name if relocatable-device-code
+  // is specified, so we postfix it with CUID, which is unique.
+  if (CGM.getASTContext().shouldExternalize(ND) &&
+      CGM.getLangOpts().GPURelocatableDeviceCode &&
+      CGM.getLangOpts().CUDAIsDevice) {
+      // ptxas does not allow '.' in symbol names. On the other hand, HIP prefers
+      // postfix beginning with '.' since the symbol name can be demangled.
+      if (CGM.getLangOpts().HIP)
+        Out << (isa<VarDecl>(ND) ? ".static." : ".intern.");
+      else
+        Out << (isa<VarDecl>(ND) ? "__static__" : "__intern__");
+
+      // TODO: generate a unique id with other means
+      assert(!CGM.getLangOpts().CUID.empty() && "NYI");
+      Out << CGM.getASTContext().getCUIDHash();
+  }
 
   return std::string(Out.str());
 }
@@ -2325,8 +2341,6 @@ StringRef CIRGenModule::getMangledName(GlobalDecl GD) {
     }
   }
 
-  assert(!langOpts.CUDAIsDevice && "NYI");
-
   // Keep the first result in the case of a mangling collision.
   const auto *ND = cast<NamedDecl>(GD.getDecl());
   std::string MangledName = getMangledNameImpl(*this, GD, ND);