Cloning a function now also clones its debug metadata if 'ModuleLevelChanges' is true.

llvm-svn: 203662

3 files changed, 270 insertions, 2 deletions

diff --git a/llvm/include/llvm/Transforms/Utils/Cloning.h b/llvm/include/llvm/Transforms/Utils/Cloning.h
index 13532e80093..96c650834aa 100644
--- a/llvm/include/llvm/Transforms/Utils/Cloning.h
+++ b/llvm/include/llvm/Transforms/Utils/Cloning.h
@@ -109,7 +109,7 @@ BasicBlock *CloneBasicBlock(const BasicBlock *BB,
 /// information about the cloned code if non-null.
 ///
 /// If ModuleLevelChanges is false, VMap contains no non-identity GlobalValue
-/// mappings.
+/// mappings, and debug info metadata will not be cloned.
 ///
 Function *CloneFunction(const Function *F,
                         ValueToValueMapTy &VMap,
diff --git a/llvm/lib/Transforms/Utils/CloneFunction.cpp b/llvm/lib/Transforms/Utils/CloneFunction.cpp
index 6001a9bf607..22222112f17 100644
--- a/llvm/lib/Transforms/Utils/CloneFunction.cpp
+++ b/llvm/lib/Transforms/Utils/CloneFunction.cpp
@@ -27,6 +27,7 @@
 #include "llvm/IR/IntrinsicInst.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Metadata.h"
+#include "llvm/IR/Module.h"
 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
 #include "llvm/Transforms/Utils/Local.h"
 #include "llvm/Transforms/Utils/ValueMapper.h"
@@ -151,6 +152,60 @@ void llvm::CloneFunctionInto(Function *NewFunc, const Function *OldFunc,
                        TypeMapper, Materializer);
 }
 
+// Find the MDNode which corresponds to the DISubprogram data that described F.
+static MDNode* FindSubprogram(const Function *F, DebugInfoFinder &Finder) {
+  for (DebugInfoFinder::iterator I = Finder.subprogram_begin(),
+                                 E = Finder.subprogram_end();
+       I != E; ++I) {
+    DISubprogram Subprogram(*I);
+    if (Subprogram.describes(F)) return Subprogram;
+  }
+  return NULL;
+}
+
+// Add an operand to an existing MDNode. The new operand will be added at the
+// back of the operand list.
+static void AddOperand(MDNode *Node, Value *Operand) {
+  SmallVector<Value*, 16> Operands;
+  for (unsigned i = 0; i < Node->getNumOperands(); i++) {
+    Operands.push_back(Node->getOperand(i));
+  }
+  Operands.push_back(Operand);
+  MDNode *NewNode = MDNode::get(Node->getContext(), Operands);
+  Node->replaceAllUsesWith(NewNode);
+}
+
+// Clone the module-level debug info associated with OldFunc. The cloned data
+// will point to NewFunc instead.
+static void CloneDebugInfoMetadata(Function *NewFunc, const Function *OldFunc,
+                            ValueToValueMapTy &VMap) {
+  DebugInfoFinder Finder;
+  Finder.processModule(*OldFunc->getParent());
+
+  const MDNode *OldSubprogramMDNode = FindSubprogram(OldFunc, Finder);
+  if (!OldSubprogramMDNode) return;
+
+  // Ensure that OldFunc appears in the map.
+  // (if it's already there it must point to NewFunc anyway)
+  VMap[OldFunc] = NewFunc;
+  DISubprogram NewSubprogram(MapValue(OldSubprogramMDNode, VMap));
+
+  for (DebugInfoFinder::iterator CUIter = Finder.compile_unit_begin(),
+       CUEnd = Finder.compile_unit_end(); CUIter != CUEnd; ++CUIter) {
+    DICompileUnit CU(*CUIter);
+
+    DIArray Subprograms(CU.getSubprograms());
+
+    // If the compile unit's function list contains the old function, it should
+    // also contain the new one.
+    for (unsigned i = 0; i < Subprograms.getNumElements(); i++) {
+      if ((MDNode*)Subprograms.getElement(i) == OldSubprogramMDNode) {
+        AddOperand(Subprograms, NewSubprogram);
+      }
+    }
+  }
+}
+
 /// CloneFunction - Return a copy of the specified function, but without
 /// embedding the function into another module.  Also, any references specified
 /// in the VMap are changed to refer to their mapped value instead of the
@@ -188,6 +243,9 @@ Function *llvm::CloneFunction(const Function *F, ValueToValueMapTy &VMap,
       VMap[I] = DestI++;        // Add mapping to VMap
     }
 
+  if (ModuleLevelChanges)
+    CloneDebugInfoMetadata(NewF, F, VMap);
+
   SmallVector<ReturnInst*, 8> Returns;  // Ignore returns cloned.
   CloneFunctionInto(NewF, F, VMap, ModuleLevelChanges, Returns, "", CodeInfo);
   return NewF;
diff --git a/llvm/unittests/Transforms/Utils/Cloning.cpp b/llvm/unittests/Transforms/Utils/Cloning.cpp
index 25812470b14..0ff80d6f8a8 100644
--- a/llvm/unittests/Transforms/Utils/Cloning.cpp
+++ b/llvm/unittests/Transforms/Utils/Cloning.cpp
@@ -7,15 +7,22 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "llvm/Transforms/Utils/Cloning.h"
+#include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/IR/Argument.h"
 #include "llvm/IR/Constant.h"
+#include "llvm/IR/DebugInfo.h"
+#include "llvm/IR/DIBuilder.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/InstIterator.h"
 #include "llvm/IR/Instructions.h"
+#include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/Module.h"
 #include "llvm/IR/LLVMContext.h"
-#include "llvm/Transforms/Utils/Cloning.h"
 #include "gtest/gtest.h"
 
 using namespace llvm;
@@ -173,4 +180,207 @@ TEST_F(CloneInstruction, Attributes) {
   delete F2;
 }
 
+class CloneFunc : public ::testing::Test {
+protected:
+  virtual void SetUp() {
+    SetupModule();
+    CreateOldFunc();
+    CreateNewFunc();
+    SetupFinder();
+  }
+
+  virtual void TearDown() {
+    delete Finder;
+  }
+
+  void SetupModule() {
+    M = new Module("", C);
+  }
+
+  void CreateOldFunc() {
+    FunctionType* FuncType = FunctionType::get(Type::getVoidTy(C), false);
+    OldFunc = Function::Create(FuncType, GlobalValue::PrivateLinkage, "f", M);
+    CreateOldFunctionBodyAndDI();
+  }
+
+  void CreateOldFunctionBodyAndDI() {
+    DIBuilder DBuilder(*M);
+    IRBuilder<> IBuilder(C);
+
+    // Function DI
+    DIFile File = DBuilder.createFile("filename.c", "/file/dir/");
+    DIArray ParamTypes = DBuilder.getOrCreateArray(ArrayRef<Value*>());
+    DICompositeType FuncType = DBuilder.createSubroutineType(File, ParamTypes);
+    DICompileUnit CU = DBuilder.createCompileUnit(dwarf::DW_LANG_C99,
+        "filename.c", "/file/dir", "CloneFunc", false, "", 0);
+
+    DISubprogram Subprogram = DBuilder.createFunction(CU, "f", "f", File, 4,
+        FuncType, true, true, 3, 0, false, OldFunc);
+
+    // Function body
+    BasicBlock* Entry = BasicBlock::Create(C, "", OldFunc);
+    IBuilder.SetInsertPoint(Entry);
+    DebugLoc Loc = DebugLoc::get(3, 2, Subprogram);
+    IBuilder.SetCurrentDebugLocation(Loc);
+    AllocaInst* Alloca = IBuilder.CreateAlloca(IntegerType::getInt32Ty(C));
+    IBuilder.SetCurrentDebugLocation(DebugLoc::get(4, 2, Subprogram));
+    Value* AllocaContent = IBuilder.getInt32(1);
+    Instruction* Store = IBuilder.CreateStore(AllocaContent, Alloca);
+    IBuilder.SetCurrentDebugLocation(DebugLoc::get(5, 2, Subprogram));
+    Instruction* Terminator = IBuilder.CreateRetVoid();
+
+    // Create a local variable around the alloca
+    DIType IntType = DBuilder.createBasicType("int", 32, 0,
+        dwarf::DW_ATE_signed);
+    DIVariable Variable = DBuilder.createLocalVariable(
+      dwarf::DW_TAG_auto_variable, Subprogram, "x", File, 5, IntType, true);
+    DBuilder.insertDeclare(Alloca, Variable, Store);
+    DBuilder.insertDbgValueIntrinsic(AllocaContent, 0, Variable, Terminator);
+    // Finalize the debug info
+    DBuilder.finalize();
+
+
+    // Create another, empty, compile unit
+    DIBuilder DBuilder2(*M);
+    DBuilder2.createCompileUnit(dwarf::DW_LANG_C99,
+        "extra.c", "/file/dir", "CloneFunc", false, "", 0);
+    DBuilder2.finalize();
+  }
+
+  void CreateNewFunc() {
+    ValueToValueMapTy VMap;
+    NewFunc = CloneFunction(OldFunc, VMap, true, NULL);
+    M->getFunctionList().push_back(NewFunc);
+  }
+
+  void SetupFinder() {
+    Finder = new DebugInfoFinder();
+    Finder->processModule(*M);
+  }
+
+  LLVMContext C;
+  Function* OldFunc;
+  Function* NewFunc;
+  Module* M;
+  DebugInfoFinder* Finder;
+};
+
+// Test that a new, distinct function was created.
+TEST_F(CloneFunc, NewFunctionCreated) {
+  EXPECT_NE(OldFunc, NewFunc);
+}
+
+// Test that a new subprogram entry was added and is pointing to the new
+// function, while the original subprogram still points to the old one.
+TEST_F(CloneFunc, Subprogram) {
+  unsigned SubprogramCount = Finder->subprogram_count();
+  EXPECT_EQ(2, SubprogramCount);
+
+  DebugInfoFinder::iterator Iter = Finder->subprogram_begin();
+  DISubprogram Sub1(*Iter);
+  EXPECT_TRUE(Sub1.Verify());
+  Iter++;
+  DISubprogram Sub2(*Iter);
+  EXPECT_TRUE(Sub2.Verify());
+
+  EXPECT_TRUE(Sub1.getFunction() == OldFunc && Sub2.getFunction() == NewFunc
+           || Sub1.getFunction() == NewFunc && Sub2.getFunction() == OldFunc);
+}
+
+// Test that the new subprogram entry was not added to the CU which doesn't
+// contain the old subprogram entry.
+TEST_F(CloneFunc, SubprogramInRightCU) {
+  EXPECT_EQ(2, Finder->compile_unit_count());
+
+  DebugInfoFinder::iterator Iter = Finder->compile_unit_begin();
+  DICompileUnit CU1(*Iter);
+  EXPECT_TRUE(CU1.Verify());
+  Iter++;
+  DICompileUnit CU2(*Iter);
+  EXPECT_TRUE(CU2.Verify());
+  EXPECT_TRUE(CU1.getSubprograms().getNumElements() == 0
+           || CU2.getSubprograms().getNumElements() == 0);
+}
+
+// Test that instructions in the old function still belong to it in the
+// metadata, while instruction in the new function belong to the new one.
+TEST_F(CloneFunc, InstructionOwnership) {
+  inst_iterator OldIter = inst_begin(OldFunc);
+  inst_iterator OldEnd = inst_end(OldFunc);
+  inst_iterator NewIter = inst_begin(NewFunc);
+  inst_iterator NewEnd = inst_end(NewFunc);
+  while (OldIter != OldEnd && NewIter != NewEnd) {
+    Instruction& OldI = *OldIter;
+    Instruction& NewI = *NewIter;
+    EXPECT_NE(&OldI, &NewI);
+
+    EXPECT_EQ(OldI.hasMetadata(), NewI.hasMetadata());
+    if (OldI.hasMetadata()) {
+      const DebugLoc& OldDL = OldI.getDebugLoc();
+      const DebugLoc& NewDL = NewI.getDebugLoc();
+
+      // Verify that the debug location data is the same
+      EXPECT_EQ(OldDL.getLine(), NewDL.getLine());
+      EXPECT_EQ(OldDL.getCol(), NewDL.getCol());
+      
+      // But that they belong to different functions
+      DISubprogram OldSubprogram(OldDL.getScope(C));
+      DISubprogram NewSubprogram(NewDL.getScope(C));
+      EXPECT_TRUE(OldSubprogram.Verify());
+      EXPECT_TRUE(NewSubprogram.Verify());
+      EXPECT_EQ(OldFunc, OldSubprogram.getFunction());
+      EXPECT_EQ(NewFunc, NewSubprogram.getFunction());
+    }
+
+    ++OldIter;
+    ++NewIter;
+  }
+  EXPECT_EQ(OldEnd, OldIter);
+  EXPECT_EQ(NewEnd, NewIter);
+}
+
+// Test that the arguments for debug intrinsics in the new function were
+// properly cloned
+TEST_F(CloneFunc, DebugIntrinsics) {
+  inst_iterator OldIter = inst_begin(OldFunc);
+  inst_iterator OldEnd = inst_end(OldFunc);
+  inst_iterator NewIter = inst_begin(NewFunc);
+  inst_iterator NewEnd = inst_end(NewFunc);
+  while (OldIter != OldEnd && NewIter != NewEnd) {
+    Instruction& OldI = *OldIter;
+    Instruction& NewI = *NewIter;
+    if (DbgDeclareInst* OldIntrin = dyn_cast<DbgDeclareInst>(&OldI)) {
+      DbgDeclareInst* NewIntrin = dyn_cast<DbgDeclareInst>(&NewI);
+      EXPECT_TRUE(NewIntrin);
+
+      // Old address must belong to the old function
+      EXPECT_EQ(OldFunc, cast<AllocaInst>(OldIntrin->getAddress())->
+                         getParent()->getParent());
+      // New address must belong to the new function
+      EXPECT_EQ(NewFunc, cast<AllocaInst>(NewIntrin->getAddress())->
+                         getParent()->getParent());
+
+      // Old variable must belong to the old function
+      EXPECT_EQ(OldFunc, DISubprogram(DIVariable(OldIntrin->getVariable())
+                         .getContext()).getFunction());
+      // New variable must belong to the New function
+      EXPECT_EQ(NewFunc, DISubprogram(DIVariable(NewIntrin->getVariable())
+                         .getContext()).getFunction());
+    } else if (DbgValueInst* OldIntrin = dyn_cast<DbgValueInst>(&OldI)) {
+      DbgValueInst* NewIntrin = dyn_cast<DbgValueInst>(&NewI);
+      EXPECT_TRUE(NewIntrin);
+
+      // Old variable must belong to the old function
+      EXPECT_EQ(OldFunc, DISubprogram(DIVariable(OldIntrin->getVariable())
+                         .getContext()).getFunction());
+      // New variable must belong to the New function
+      EXPECT_EQ(NewFunc, DISubprogram(DIVariable(NewIntrin->getVariable())
+                         .getContext()).getFunction());
+    }
+
+    ++OldIter;
+    ++NewIter;
+  }
+}
+
 }