1 files changed, 215 insertions, 0 deletions
diff --git a/contrib/llvm-project/llvm/lib/Transforms/Utils/CloneModule.cpp b/contrib/llvm-project/llvm/lib/Transforms/Utils/CloneModule.cpp
new file mode 100644
index 000000000000..a6327bbf21bc
--- /dev/null
+++ b/contrib/llvm-project/llvm/lib/Transforms/Utils/CloneModule.cpp
@@ -0,0 +1,215 @@
+//===- CloneModule.cpp - Clone an entire module ---------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the CloneModule interface which makes a copy of an
+// entire module.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/IR/Constant.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Transforms/Utils/Cloning.h"
+#include "llvm/Transforms/Utils/ValueMapper.h"
+using namespace llvm;
+
+static void copyComdat(GlobalObject *Dst, const GlobalObject *Src) {
+  const Comdat *SC = Src->getComdat();
+  if (!SC)
+    return;
+  Comdat *DC = Dst->getParent()->getOrInsertComdat(SC->getName());
+  DC->setSelectionKind(SC->getSelectionKind());
+  Dst->setComdat(DC);
+}
+
+/// This is not as easy as it might seem because we have to worry about making
+/// copies of global variables and functions, and making their (initializers and
+/// references, respectively) refer to the right globals.
+///
+std::unique_ptr<Module> llvm::CloneModule(const Module &M) {
+  // Create the value map that maps things from the old module over to the new
+  // module.
+  ValueToValueMapTy VMap;
+  return CloneModule(M, VMap);
+}
+
+std::unique_ptr<Module> llvm::CloneModule(const Module &M,
+                                          ValueToValueMapTy &VMap) {
+  return CloneModule(M, VMap, [](const GlobalValue *GV) { return true; });
+}
+
+std::unique_ptr<Module> llvm::CloneModule(
+    const Module &M, ValueToValueMapTy &VMap,
+    function_ref<bool(const GlobalValue *)> ShouldCloneDefinition) {
+  // First off, we need to create the new module.
+  std::unique_ptr<Module> New =
+      std::make_unique<Module>(M.getModuleIdentifier(), M.getContext());
+  New->setSourceFileName(M.getSourceFileName());
+  New->setDataLayout(M.getDataLayout());
+  New->setTargetTriple(M.getTargetTriple());
+  New->setModuleInlineAsm(M.getModuleInlineAsm());
+
+  // Loop over all of the global variables, making corresponding globals in the
+  // new module.  Here we add them to the VMap and to the new Module.  We
+  // don't worry about attributes or initializers, they will come later.
+  //
+  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
+       I != E; ++I) {
+    GlobalVariable *GV = new GlobalVariable(*New,
+                                            I->getValueType(),
+                                            I->isConstant(), I->getLinkage(),
+                                            (Constant*) nullptr, I->getName(),
+                                            (GlobalVariable*) nullptr,
+                                            I->getThreadLocalMode(),
+                                            I->getType()->getAddressSpace());
+    GV->copyAttributesFrom(&*I);
+    VMap[&*I] = GV;
+  }
+
+  // Loop over the functions in the module, making external functions as before
+  for (const Function &I : M) {
+    Function *NF =
+        Function::Create(cast<FunctionType>(I.getValueType()), I.getLinkage(),
+                         I.getAddressSpace(), I.getName(), New.get());
+    NF->copyAttributesFrom(&I);
+    VMap[&I] = NF;
+  }
+
+  // Loop over the aliases in the module
+  for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
+       I != E; ++I) {
+    if (!ShouldCloneDefinition(&*I)) {
+      // An alias cannot act as an external reference, so we need to create
+      // either a function or a global variable depending on the value type.
+      // FIXME: Once pointee types are gone we can probably pick one or the
+      // other.
+      GlobalValue *GV;
+      if (I->getValueType()->isFunctionTy())
+        GV = Function::Create(cast<FunctionType>(I->getValueType()),
+                              GlobalValue::ExternalLinkage,
+                              I->getAddressSpace(), I->getName(), New.get());
+      else
+        GV = new GlobalVariable(
+            *New, I->getValueType(), false, GlobalValue::ExternalLinkage,
+            nullptr, I->getName(), nullptr,
+            I->getThreadLocalMode(), I->getType()->getAddressSpace());
+      VMap[&*I] = GV;
+      // We do not copy attributes (mainly because copying between different
+      // kinds of globals is forbidden), but this is generally not required for
+      // correctness.
+      continue;
+    }
+    auto *GA = GlobalAlias::create(I->getValueType(),
+                                   I->getType()->getPointerAddressSpace(),
+                                   I->getLinkage(), I->getName(), New.get());
+    GA->copyAttributesFrom(&*I);
+    VMap[&*I] = GA;
+  }
+
+  // Now that all of the things that global variable initializer can refer to
+  // have been created, loop through and copy the global variable referrers
+  // over...  We also set the attributes on the global now.
+  //
+  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
+       I != E; ++I) {
+    GlobalVariable *GV = cast<GlobalVariable>(VMap[&*I]);
+
+    SmallVector<std::pair<unsigned, MDNode *>, 1> MDs;
+    I->getAllMetadata(MDs);
+    for (auto MD : MDs)
+      GV->addMetadata(MD.first,
+                      *MapMetadata(MD.second, VMap, RF_MoveDistinctMDs));
+
+    if (I->isDeclaration())
+      continue;
+
+    if (!ShouldCloneDefinition(&*I)) {
+      // Skip after setting the correct linkage for an external reference.
+      GV->setLinkage(GlobalValue::ExternalLinkage);
+      continue;
+    }
+    if (I->hasInitializer())
+      GV->setInitializer(MapValue(I->getInitializer(), VMap));
+
+    copyComdat(GV, &*I);
+  }
+
+  // Similarly, copy over function bodies now...
+  //
+  for (const Function &I : M) {
+    if (I.isDeclaration())
+      continue;
+
+    Function *F = cast<Function>(VMap[&I]);
+    if (!ShouldCloneDefinition(&I)) {
+      // Skip after setting the correct linkage for an external reference.
+      F->setLinkage(GlobalValue::ExternalLinkage);
+      // Personality function is not valid on a declaration.
+      F->setPersonalityFn(nullptr);
+      continue;
+    }
+
+    Function::arg_iterator DestI = F->arg_begin();
+    for (Function::const_arg_iterator J = I.arg_begin(); J != I.arg_end();
+         ++J) {
+      DestI->setName(J->getName());
+      VMap[&*J] = &*DestI++;
+    }
+
+    SmallVector<ReturnInst *, 8> Returns; // Ignore returns cloned.
+    CloneFunctionInto(F, &I, VMap, /*ModuleLevelChanges=*/true, Returns);
+
+    if (I.hasPersonalityFn())
+      F->setPersonalityFn(MapValue(I.getPersonalityFn(), VMap));
+
+    copyComdat(F, &I);
+  }
+
+  // And aliases
+  for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
+       I != E; ++I) {
+    // We already dealt with undefined aliases above.
+    if (!ShouldCloneDefinition(&*I))
+      continue;
+    GlobalAlias *GA = cast<GlobalAlias>(VMap[&*I]);
+    if (const Constant *C = I->getAliasee())
+      GA->setAliasee(MapValue(C, VMap));
+  }
+
+  // And named metadata....
+  const auto* LLVM_DBG_CU = M.getNamedMetadata("llvm.dbg.cu");
+  for (Module::const_named_metadata_iterator I = M.named_metadata_begin(),
+                                             E = M.named_metadata_end();
+       I != E; ++I) {
+    const NamedMDNode &NMD = *I;
+    NamedMDNode *NewNMD = New->getOrInsertNamedMetadata(NMD.getName());
+    if (&NMD == LLVM_DBG_CU) {
+      // Do not insert duplicate operands.
+      SmallPtrSet<const void*, 8> Visited;
+      for (const auto* Operand : NewNMD->operands())
+        Visited.insert(Operand);
+      for (const auto* Operand : NMD.operands()) {
+        auto* MappedOperand = MapMetadata(Operand, VMap);
+        if (Visited.insert(MappedOperand).second)
+          NewNMD->addOperand(MappedOperand);
+      }
+    } else
+      for (unsigned i = 0, e = NMD.getNumOperands(); i != e; ++i)
+        NewNMD->addOperand(MapMetadata(NMD.getOperand(i), VMap));
+  }
+
+  return New;
+}
+
+extern "C" {
+
+LLVMModuleRef LLVMCloneModule(LLVMModuleRef M) {
+  return wrap(CloneModule(*unwrap(M)).release());
+}
+
+}