Initial checkin of Module cloning support stuff

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@4788 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 179 insertions, 4 deletions

diff --git a/lib/Transforms/Utils/CloneFunction.cpp b/lib/Transforms/Utils/CloneFunction.cpp
index 29c7aaa037..ca22003b40 100644
--- a/lib/Transforms/Utils/CloneFunction.cpp
+++ b/lib/Transforms/Utils/CloneFunction.cpp
@@ -10,6 +10,7 @@
 #include "llvm/iTerminators.h"
 #include "llvm/DerivedTypes.h"
 #include "llvm/Function.h"
+#include "ValueMapper.h"
 
 // RemapInstruction - Convert the instruction operands from referencing the 
 // current values into those specified by ValueMap.
@@ -18,10 +19,7 @@ static inline void RemapInstruction(Instruction *I,
                                     std::map<const Value *, Value*> &ValueMap) {
   for (unsigned op = 0, E = I->getNumOperands(); op != E; ++op) {
     const Value *Op = I->getOperand(op);
-    Value *V = ValueMap[Op];
-    if (!V && (isa<GlobalValue>(Op) || isa<Constant>(Op)))
-      continue;  // Globals and constants don't get relocated
-
+    Value *V = MapValue(Op, ValueMap);
 #ifndef NDEBUG
     if (!V) {
       std::cerr << "Val = \n" << Op << "Addr = " << (void*)Op;
diff --git a/lib/Transforms/Utils/CloneModule.cpp b/lib/Transforms/Utils/CloneModule.cpp
new file mode 100644
index 0000000000..043e06d543
--- /dev/null
+++ b/lib/Transforms/Utils/CloneModule.cpp
@@ -0,0 +1,73 @@
+//===- CloneModule.cpp - Clone an entire module ---------------------------===//
+//
+// This file implements the CloneModule interface which makes a copy of an
+// entire module.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Transforms/Utils/Cloning.h"
+#include "llvm/Module.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Constant.h"
+#include "ValueMapper.h"
+
+/// CloneModule - Return an exact copy of the specified module.  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 (intializers and references,
+/// respectively) refer to the right globals.
+///
+Module *CloneModule(const Module *M) {
+  // First off, we need to create the new module...
+  Module *New = new Module();
+
+  // Create the value map that maps things from the old module over to the new
+  // module.
+  std::map<const Value*, Value*> ValueMap;
+
+  // Loop over all of the global variables, making corresponding globals in the
+  // new module.  Here we add them to the ValueMap and to the new Module.  We
+  // don't worry about attributes or initializers, they will come later.
+  //
+  for (Module::const_giterator I = M->gbegin(), E = M->gend(); I != E; ++I)
+    ValueMap[I] = new GlobalVariable(I->getType()->getElementType(),
+                                     false, false, 0, I->getName(), New);
+
+  // Loop over the functions in the module, making external functions as before
+  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
+    ValueMap[I]=new Function(cast<FunctionType>(I->getType()->getElementType()),
+                             false, I->getName(), New);
+
+  // 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_giterator I = M->gbegin(), E = M->gend(); I != E; ++I) {
+    GlobalVariable *GV = cast<GlobalVariable>(ValueMap[I]);
+    if (I->hasInitializer())
+      GV->setInitializer(cast<Constant>(MapValue(I->getInitializer(),
+                                                 ValueMap)));
+    if (I->hasInternalLinkage())
+      GV->setInternalLinkage(true);
+  }
+
+  // Similarly, copy over function bodies now...
+  //
+  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I) {
+    Function *F = cast<Function>(ValueMap[I]);
+    if (!I->isExternal()) {
+      Function::aiterator DestI = F->abegin();
+      for (Function::const_aiterator J = I->abegin(); J != I->aend(); ++J) {
+        DestI->setName(J->getName());
+        ValueMap[J] = DestI++;
+      }
+
+      std::vector<ReturnInst*> Returns;  // Ignore returns cloned...
+      CloneFunctionInto(F, I, ValueMap, Returns);
+    }
+
+    if (I->hasInternalLinkage())
+      F->setInternalLinkage(true);
+  }
+
+  return New;
+}
diff --git a/lib/Transforms/Utils/ValueMapper.cpp b/lib/Transforms/Utils/ValueMapper.cpp
new file mode 100644
index 0000000000..e6ab297428
--- /dev/null
+++ b/lib/Transforms/Utils/ValueMapper.cpp
@@ -0,0 +1,88 @@
+//===- ValueMapper.cpp - Interface shared by lib/Transforms/Utils ---------===//
+//
+// This file defines the MapValue function, which is shared by various parts of
+// the lib/Transforms/Utils library.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ValueMapper.h"
+#include "llvm/Constants.h"
+#include "llvm/Instruction.h"
+
+Value *MapValue(const Value *V, std::map<const Value*, Value*> &VM) {
+  Value *&VMSlot = VM[V];
+  if (VMSlot) return VMSlot;      // Does it exist in the map yet?
+  
+  if (Constant *C = (Constant*)dyn_cast<Constant>(V)) {
+    if (isa<ConstantIntegral>(C) || isa<ConstantFP>(C) ||
+        isa<ConstantPointerNull>(C))
+      return VMSlot = C;           // Primitive constants map directly
+    else if (ConstantPointerRef *CPR = dyn_cast<ConstantPointerRef>(C)) {
+      GlobalValue *MV = cast<GlobalValue>(MapValue((Value*)CPR->getValue(),VM));
+      return VMSlot = ConstantPointerRef::get(MV);
+    } else if (ConstantArray *CA = dyn_cast<ConstantArray>(C)) {
+      const std::vector<Use> &Vals = CA->getValues();
+      for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
+        Value *MV = MapValue(Vals[i], VM);
+        if (MV != Vals[i]) {
+          // This array must contain a reference to a global, make a new array
+          // and return it.
+          //
+          std::vector<Constant*> Values;
+          Values.reserve(Vals.size());
+          for (unsigned j = 0; j != i; ++j)
+            Values.push_back(cast<Constant>(Vals[j]));
+          Values.push_back(cast<Constant>(MV));
+          for (; i != e; ++i)
+            Values.push_back(cast<Constant>(MapValue(Vals[i], VM)));
+          return VMSlot = ConstantArray::get(CA->getType(), Values);
+        }
+      }
+      return VMSlot = C;
+
+    } else if (ConstantStruct *CS = dyn_cast<ConstantStruct>(C)) {
+      const std::vector<Use> &Vals = CS->getValues();
+      for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
+        Value *MV = MapValue(Vals[i], VM);
+        if (MV != Vals[i]) {
+          // This struct must contain a reference to a global, make a new struct
+          // and return it.
+          //
+          std::vector<Constant*> Values;
+          Values.reserve(Vals.size());
+          for (unsigned j = 0; j != i; ++j)
+            Values.push_back(cast<Constant>(Vals[j]));
+          Values.push_back(cast<Constant>(MV));
+          for (; i != e; ++i)
+            Values.push_back(cast<Constant>(MapValue(Vals[i], VM)));
+          return VMSlot = ConstantStruct::get(CS->getType(), Values);
+        }
+      }
+      return VMSlot = C;
+
+    } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
+      if (CE->getOpcode() == Instruction::Cast) {
+        Constant *MV = cast<Constant>(MapValue(CE->getOperand(0), VM));
+        return VMSlot = ConstantExpr::getCast(MV, CE->getType());
+      } else if (CE->getOpcode() == Instruction::GetElementPtr) {
+        std::vector<Constant*> Idx;
+        Constant *MV = cast<Constant>(MapValue(CE->getOperand(0), VM));
+        for (unsigned i = 1, e = CE->getNumOperands(); i != e; ++i)
+          Idx.push_back(cast<Constant>(MapValue(CE->getOperand(i), VM)));
+        return VMSlot = ConstantExpr::getGetElementPtr(MV, Idx);
+      } else {
+        assert(CE->getNumOperands() == 2 && "Must be binary operator?");
+        Constant *MV1 = cast<Constant>(MapValue(CE->getOperand(0), VM));
+        Constant *MV2 = cast<Constant>(MapValue(CE->getOperand(1), VM));
+        return VMSlot = ConstantExpr::get(CE->getOpcode(), MV1, MV2);
+      }
+
+    } else {
+      assert(0 && "Unknown type of constant!");
+    }
+  }
+  
+  assert(0 && "Unknown value type: why didn't it get resolved?!");
+  return 0;
+}
+
diff --git a/lib/Transforms/Utils/ValueMapper.h b/lib/Transforms/Utils/ValueMapper.h
new file mode 100644
index 0000000000..23f7058858
--- /dev/null
+++ b/lib/Transforms/Utils/ValueMapper.h
@@ -0,0 +1,16 @@
+//===- ValueMapper.h - Interface shared by lib/Transforms/Utils -*- C++ -*-===//
+//
+// This file defines the MapValue interface which is used by various parts of
+// the Transforms/Utils library to implement cloning and linking facilities.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LIB_TRANSFORMS_UTILS_VALUE_MAPPER_H
+#define LIB_TRANSFORMS_UTILS_VALUE_MAPPER_H
+
+#include <map>
+class Value;
+
+Value *MapValue(const Value *V, std::map<const Value*, Value*> &VM);
+
+#endif