1 files changed, 95 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Transforms/Utils/ModuleUtils.cpp b/contrib/llvm/lib/Transforms/Utils/ModuleUtils.cpp
new file mode 100644
index 0000000..d9dbbca
--- /dev/null
+++ b/contrib/llvm/lib/Transforms/Utils/ModuleUtils.cpp
@@ -0,0 +1,95 @@
+//===-- ModuleUtils.cpp - Functions to manipulate Modules -----------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This family of functions perform manipulations on Modules.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Transforms/Utils/ModuleUtils.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/Module.h"
+
+using namespace llvm;
+
+static void appendToGlobalArray(const char *Array, 
+                                Module &M, Function *F, int Priority) {
+  IRBuilder<> IRB(M.getContext());
+  FunctionType *FnTy = FunctionType::get(IRB.getVoidTy(), false);
+
+  // Get the current set of static global constructors and add the new ctor
+  // to the list.
+  SmallVector<Constant *, 16> CurrentCtors;
+  StructType *EltTy;
+  if (GlobalVariable *GVCtor = M.getNamedGlobal(Array)) {
+    // If there is a global_ctors array, use the existing struct type, which can
+    // have 2 or 3 fields.
+    ArrayType *ATy = cast<ArrayType>(GVCtor->getType()->getElementType());
+    EltTy = cast<StructType>(ATy->getElementType());
+    if (Constant *Init = GVCtor->getInitializer()) {
+      unsigned n = Init->getNumOperands();
+      CurrentCtors.reserve(n + 1);
+      for (unsigned i = 0; i != n; ++i)
+        CurrentCtors.push_back(cast<Constant>(Init->getOperand(i)));
+    }
+    GVCtor->eraseFromParent();
+  } else {
+    // Use a simple two-field struct if there isn't one already.
+    EltTy = StructType::get(IRB.getInt32Ty(), PointerType::getUnqual(FnTy),
+                            nullptr);
+  }
+
+  // Build a 2 or 3 field global_ctor entry.  We don't take a comdat key.
+  Constant *CSVals[3];
+  CSVals[0] = IRB.getInt32(Priority);
+  CSVals[1] = F;
+  // FIXME: Drop support for the two element form in LLVM 4.0.
+  if (EltTy->getNumElements() >= 3)
+    CSVals[2] = llvm::Constant::getNullValue(IRB.getInt8PtrTy());
+  Constant *RuntimeCtorInit =
+      ConstantStruct::get(EltTy, makeArrayRef(CSVals, EltTy->getNumElements()));
+
+  CurrentCtors.push_back(RuntimeCtorInit);
+
+  // Create a new initializer.
+  ArrayType *AT = ArrayType::get(EltTy, CurrentCtors.size());
+  Constant *NewInit = ConstantArray::get(AT, CurrentCtors);
+
+  // Create the new global variable and replace all uses of
+  // the old global variable with the new one.
+  (void)new GlobalVariable(M, NewInit->getType(), false,
+                           GlobalValue::AppendingLinkage, NewInit, Array);
+}
+
+void llvm::appendToGlobalCtors(Module &M, Function *F, int Priority) {
+  appendToGlobalArray("llvm.global_ctors", M, F, Priority);
+}
+
+void llvm::appendToGlobalDtors(Module &M, Function *F, int Priority) {
+  appendToGlobalArray("llvm.global_dtors", M, F, Priority);
+}
+
+GlobalVariable *
+llvm::collectUsedGlobalVariables(Module &M, SmallPtrSet<GlobalValue *, 8> &Set,
+                                 bool CompilerUsed) {
+  const char *Name = CompilerUsed ? "llvm.compiler.used" : "llvm.used";
+  GlobalVariable *GV = M.getGlobalVariable(Name);
+  if (!GV || !GV->hasInitializer())
+    return GV;
+
+  const ConstantArray *Init = cast<ConstantArray>(GV->getInitializer());
+  for (unsigned I = 0, E = Init->getNumOperands(); I != E; ++I) {
+    Value *Op = Init->getOperand(I);
+    GlobalValue *G = cast<GlobalValue>(Op->stripPointerCastsNoFollowAliases());
+    Set.insert(G);
+  }
+  return GV;
+}