Fixed bug in symbol linking for CUDA kernel registration with LLVM 13.

Since cling was ported to LLVM 13, it is required that the
`__cuda_register_globals` function and the `__cuda_fatbin_wrapper` and
`__cuda_gpubin_handle` variables are unique when defining a CUDA kernel.
Otherwise, the JIT is lazy and reuses the compiled version of
`__cuda_register_globals`, `__cuda_fatbin_wrapper` and `__cuda_gpubin_handle`
from the first CUDA kernel definition for all subsequent CUDA kernel
definitions, which in practice means that the PTX code from the first kernel is
re-registered each time.

Increase the default CUDA SM level to 35 because SM 20 is deprecated or
removed in the current CUDA SDK versions.

lib/Interpreter/BackendPasses.cpp

@@ -127,29 +127,55 @@ char WeakTypeinfoVTablePass::ID = 0;
 
 namespace {
 
-  // Add a suffix to the CUDA module ctor/dtor to generate a unique name.
-  // This is necessary for lazy compilation. Without suffix, cling cannot
-  // distinguish ctor/dtor of subsequent modules.
+  // Add a suffix to the CUDA module ctor/dtor, CUDA specific functions and
+  // variables to generate a unique name. This is necessary for lazy
+  // compilation. Without suffix, cling cannot distinguish ctor/dtor, register
+  // function and and ptx code string of subsequent modules.
   class UniqueCUDAStructorName : public ModulePass {
     static char ID;
 
-    bool runOnFunction(Function& F, const StringRef ModuleName){
-      if(F.hasName() && (F.getName() == "__cuda_module_ctor"
-          || F.getName() == "__cuda_module_dtor") ){
-        llvm::SmallString<128> NewFunctionName;
-        NewFunctionName.append(F.getName());
-        NewFunctionName.append("_");
-        NewFunctionName.append(ModuleName);
+    // append a suffix to a symbol to make it unique
+    // the suffix is "_cling_module_<module number>"
+    llvm::SmallString<128> add_module_suffix(const StringRef SymbolName,
+                                             const StringRef ModuleName) {
+      llvm::SmallString<128> NewFunctionName;
+      NewFunctionName.append(SymbolName);
+      NewFunctionName.append("_");
+      NewFunctionName.append(ModuleName);
 
-        for (size_t i = 0; i < NewFunctionName.size(); ++i) {
-          // Replace everything that is not [a-zA-Z0-9._] with a _. This set
-          // happens to be the set of C preprocessing numbers.
-          if (!isPreprocessingNumberBody(NewFunctionName[i]))
-            NewFunctionName[i] = '_';
-        }
+      for (size_t i = 0; i < NewFunctionName.size(); ++i) {
+        // Replace everything that is not [a-zA-Z0-9._] with a _. This set
+        // happens to be the set of C preprocessing numbers.
+        if (!isPreprocessingNumberBody(NewFunctionName[i]))
+          NewFunctionName[i] = '_';
+      }
 
-        F.setName(NewFunctionName);
+      return NewFunctionName;
+    }
 
+    // make CUDA specific variables unique
+    bool runOnGlobal(GlobalValue& GV, const StringRef ModuleName) {
+      if (GV.isDeclaration())
+        return false; // no change.
+
+      if (!GV.hasName())
+        return false;
+
+      if (GV.getName().equals("__cuda_fatbin_wrapper") ||
+          GV.getName().equals("__cuda_gpubin_handle")) {
+        GV.setName(add_module_suffix(GV.getName(), ModuleName));
+        return true;
+      }
+
+      return false;
+    }
+
+    // make CUDA specific functions unique
+    bool runOnFunction(Function& F, const StringRef ModuleName) {
+      if (F.hasName() && (F.getName().equals("__cuda_module_ctor") ||
+                          F.getName().equals("__cuda_module_dtor") ||
+                          F.getName().equals("__cuda_register_globals"))) {
+        F.setName(add_module_suffix(F.getName(), ModuleName));
         return true;
       }
 
@@ -159,15 +185,17 @@ namespace {
   public:
     UniqueCUDAStructorName() : ModulePass(ID) {}
 
-    bool runOnModule(Module &M) override {
+    bool runOnModule(Module& M) override {
       bool ret = false;
       const StringRef ModuleName = M.getName();
-      for (auto &&F: M)
+      for (auto&& F : M)
         ret |= runOnFunction(F, ModuleName);
+      for (auto&& G : M.globals())
+        ret |= runOnGlobal(G, ModuleName);
       return ret;
     }
   };
-}
+} // namespace
 
 char UniqueCUDAStructorName::ID = 0;
 

lib/Interpreter/IncrementalCUDADeviceCompiler.cpp

@@ -121,7 +121,7 @@ namespace cling {
       llvm::errs()
           << "IncrementalCUDADeviceCompiler: No valid c++ standard is set.\n";
 
-    uint32_t smVersion = 20;
+    uint32_t smVersion = 35;
     if (!invocationOptions.CompilerOpts.CUDAGpuArch.empty()) {
       llvm::StringRef(invocationOptions.CompilerOpts.CUDAGpuArch)
           .drop_front(3 /* sm_ */)

test/CodeGeneration/CUDACtorDtor.C

@@ -6,9 +6,10 @@
 // LICENSE.TXT for details.
 //------------------------------------------------------------------------------
 
-// The Test checks, if the symbols __cuda_module_ctor and __cuda_module_dtor are
-// unique for every module. Attention, for a working test case, a cuda
-// fatbinary is necessary.
+// The Test checks, if the symbols __cuda_module_ctor, __cuda_module_dtor,
+// __cuda_register_globals, __cuda_fatbin_wrapper and __cuda_gpubin_handle are
+// unique for every module. Attention, for a working test case, a cuda fatbinary
+// is necessary.
 // RUN: cat %s | %cling -x cuda --cuda-path=%cudapath %cudasmlevel -Xclang -verify 2>&1 | FileCheck %s
 // REQUIRES: cuda-runtime
 
@@ -17,58 +18,113 @@
 #include "llvm/IR/Function.h"
 #include "llvm/IR/Module.h"
 #include <iostream>
+#include <map>
+#include <vector>
 
-// Compare the cuda module ctor and dtor of two random modules.
-std::string ctor1, ctor2, dtor1, dtor2;
+// for each key in the map, the test searches for a symbol in a module and
+// stores the full name in the vector in the value
+std::map<std::string, std::vector<std::string>> module_compare;
+for (std::string const& s :
+     {"__cuda_module_ctor", "__cuda_module_dtor", "__cuda_register_globals",
+      "__cuda_fatbin_wrapper", "__cuda_gpubin_handle"}) {
+  module_compare.emplace(s, std::vector<std::string>{});
+}
 
 auto T1 = gCling->getLatestTransaction();
-// only __global__ CUDA kernel definitions has the cuda module ctor and dtor
+// only __global__ CUDA kernel definitions has the cuda specific functions and
+// variables to register a kernel
 __global__ void g1() { int i = 1; }
-auto M1 = T1->getNext()->getModule();
+auto M1 = T1->getNext()->getCompiledModule();
 
-for(auto &I : *M1){
-  // The trailing '_' identify the function name as modified name.
-  if(I.getName().startswith_lower("__cuda_module_ctor_")){
-    ctor1 = I.getName().str();
+// search for the symbols in the llvm::Module M1
+for (auto const& key_value : module_compare) {
+  for (auto& I : *M1) {
+    if (I.getName().startswith(key_value.first)) {
+      module_compare[key_value.first].push_back(I.getName().str());
+    }
   }
+  for (auto& I : M1->globals()) {
+    if (I.getName().startswith(key_value.first)) {
+      module_compare[key_value.first].push_back(I.getName().str());
+    }
+  }
+}
 
-  if(I.getName().startswith_lower("__cuda_module_dtor_")){
-    dtor1 = I.getName().str();
+// verify, that each symbol was found in the module
+// if a symbol was not found, the vector should be empty
+for (auto const& key_value : module_compare) {
+  if (key_value.second.size() < 1) {
+    std::cout << "could not find symbol" << std::endl;
+    // CHECK-NOT: could not find symbol
+    std::cout << "\"" << key_value.first << "\" is not in transaction T1"
+              << std::endl;
   }
 }
 
 auto T2 = gCling->getLatestTransaction();
 __global__ void g2() { int i = 2; }
-auto M2 = T2->getNext()->getModule();
+auto M2 = T2->getNext()->getCompiledModule();
 
-// The two modules should have different names, because of the for loop.
-M1->getName().str() != M2->getName().str()
-// CHECK: (bool) true
-
-for(auto &I : *M2){
-  if(I.getName().startswith_lower("__cuda_module_ctor_")){
-    ctor2 = I.getName().str();
+// search for the symbols in the llvm::Module M2
+for (auto const& key_value : module_compare) {
+  for (auto& I : *M2) {
+    if (I.getName().startswith(key_value.first)) {
+      module_compare[key_value.first].push_back(I.getName().str());
+    }
   }
-
-  if(I.getName().startswith_lower("__cuda_module_dtor_")){
-    dtor2 = I.getName().str();
+  for (auto& I : M2->globals()) {
+    if (I.getName().startswith(key_value.first)) {
+      module_compare[key_value.first].push_back(I.getName().str());
+    }
   }
 }
 
-// Check if the ctor and dtor of the two modules are different.
-ctor1 != ctor2 // expected-note {{use '|=' to turn this inequality comparison into an or-assignment}}
-// CHECK: (bool) true
-dtor1 != dtor2 // expected-note {{use '|=' to turn this inequality comparison into an or-assignment}}
-// CHECK: (bool) true
+// verify, that each symbol was found in the second module
+for (auto const& key_value : module_compare) {
+  if (key_value.second.size() < 2) {
+    std::cout << "could not find symbol" << std::endl;
+    // CHECK-NOT: could not find symbol
+    std::cout << "\"" << key_value.first << "\" is not in transaction T2"
+              << std::endl;
+  }
+}
 
-// Check if the ctor symbol starts with the correct prefix.
-std::string expectedCtorPrefix = "__cuda_module_ctor_cling_module_";
-ctor1.compare(0, expectedCtorPrefix.length(), expectedCtorPrefix)
-// CHECK: (int) 0
+for (auto const& key_value : module_compare) {
+  std::string const generic_symbol_name = key_value.first;
+  std::string const symbol_name_suffix = generic_symbol_name + "_cling_module_";
+  std::string const T1_symbol_name = key_value.second[0];
+  std::string const T2_symbol_name = key_value.second[1];
 
-// Check if the dtor symbol starts with the correct prefix.
-std::string expectedDtorPrefix = "__cuda_module_dtor_cling_module_";
-dtor1.compare(0, expectedDtorPrefix.length(), expectedDtorPrefix)
-// CHECK: (int) 0
+  // check if each symbols are different for different modules
+  if (T1_symbol_name != T2_symbol_name) {
+    std::cout << "T1_symbol_name and T2_symbol_name are unique" << std::endl;
+    // CHECK: T1_symbol_name and T2_symbol_name are unique
+  } else {
+    std::cerr << "T1_symbol_name and T2_symbol_name are equals" << std::endl;
+    // CHECK-NOT: T1_symbol_name and T2_symbol_name are equals
+    std::cerr << T1_symbol_name << " == " << T2_symbol_name << std::endl;
+  }
 
+  // only the module number is difference for each symbol
+  // therefor the begin of the symbol name can be checked
+  if (0 != T1_symbol_name.compare(0, symbol_name_suffix.length(),
+                                  symbol_name_suffix)) {
+    std::cerr << "Wrong suffix" << std::endl;
+    // CHECK-NOT: Wrong suffix
+    std::cerr << "T1_symbol_name: " << T1_symbol_name << std::endl;
+    std::cerr << "expected symbol + suffix: " << symbol_name_suffix
+              << std::endl;
+  }
+
+  if (0 != T2_symbol_name.compare(0, symbol_name_suffix.length(),
+                                  symbol_name_suffix)) {
+    std::cerr << "Wrong suffix" << std::endl;
+    // CHECK-NOT: Wrong suffix
+    std::cerr << "T2_symbol_name: " << T2_symbol_name << std::endl;
+    std::cerr << "expected symbol + suffix: " << symbol_name_suffix
+              << std::endl;
+  }
+}
+
+// expected-no-diagnostics
 .q