Subzero: Manage each Cfg as a std::unique_ptr<Cfg>.

src/IceConverter.cpp

Index: src/IceConverter.cpp
diff --git a/src/IceConverter.cpp b/src/IceConverter.cpp
index e8ec56d18112f49120c12f10a94a10d321acf8fc..cc0a73ef024758f07ba01a39d5132702900c463b 100644
--- a/src/IceConverter.cpp
+++ b/src/IceConverter.cpp
@@ -79,15 +79,14 @@ public:
   LLVM2ICEFunctionConverter(Ice::Converter &Converter)
       : LLVM2ICEConverter(Converter), Func(nullptr) {}
 
-  // Caller is expected to delete the returned Ice::Cfg object.
-  Ice::Cfg *convertFunction(const Function *F) {
+  std::unique_ptr<Ice::Cfg> convertFunction(const Function *F) {
     VarMap.clear();
     NodeMap.clear();
     Func = Ice::Cfg::create(Ctx);
     Func->setFunctionName(F->getName());
     Func->setReturnType(convertToIceType(F->getReturnType()));
     Func->setInternal(F->hasInternalLinkage());
-    Ice::TimerMarker T(Ice::TimerStack::TT_llvmConvert, Func);
+    Ice::TimerMarker T(Ice::TimerStack::TT_llvmConvert, Func.get());
 
     // The initial definition/use of each arg is the entry node.
     for (auto ArgI = F->arg_begin(), ArgE = F->arg_end(); ArgI != ArgE;
@@ -106,7 +105,7 @@ public:
     Func->setEntryNode(mapBasicBlockToNode(&F->getEntryBlock()));
     Func->computePredecessors();
 
-    return Func;
+    return std::move(Func);

[JF, 2015/02/02 17:11:47]

This invalidates the Func data member contained in LLVM2ICEFunctionConverter.
Why does this class contain it, and then give up its ownership?

[Jim Stichnoth, 2015/02/02 18:48:48]

Yeah, I agree that's kind of weird.  The class contains it so that the class's
private methods can operate on it, but then deliberately gives it up to the
caller.

I took Karl's suggestion and made ownership/release more explicit.

This class structure should be cleaned up, but it's not that high a priority
since the code is not part of the production build.

   }
 
   // convertConstant() does not use Func or require it to be a valid
@@ -147,7 +146,7 @@ private:
     if (VarMap.find(V) == VarMap.end()) {
       VarMap[V] = Func->makeVariable(IceTy);
       if (ALLOW_DUMP)
-        VarMap[V]->setName(Func, V->getName());
+        VarMap[V]->setName(Func.get(), V->getName());
     }
     return VarMap[V];
   }
@@ -304,13 +303,13 @@ private:
   Ice::Inst *convertLoadInstruction(const LoadInst *Inst) {
     Ice::Operand *Src = convertOperand(Inst, 0);
     Ice::Variable *Dest = mapValueToIceVar(Inst);
-    return Ice::InstLoad::create(Func, Dest, Src);
+    return Ice::InstLoad::create(Func.get(), Dest, Src);
   }
 
   Ice::Inst *convertStoreInstruction(const StoreInst *Inst) {
     Ice::Operand *Addr = convertOperand(Inst, 1);
     Ice::Operand *Val = convertOperand(Inst, 0);
-    return Ice::InstStore::create(Func, Val, Addr);
+    return Ice::InstStore::create(Func.get(), Val, Addr);
   }
 
   Ice::Inst *convertArithInstruction(const Instruction *Inst,
@@ -319,13 +318,13 @@ private:
     Ice::Operand *Src0 = convertOperand(Inst, 0);
     Ice::Operand *Src1 = convertOperand(Inst, 1);
     Ice::Variable *Dest = mapValueToIceVar(BinOp);
-    return Ice::InstArithmetic::create(Func, Opcode, Dest, Src0, Src1);
+    return Ice::InstArithmetic::create(Func.get(), Opcode, Dest, Src0, Src1);
   }
 
   Ice::Inst *convertPHINodeInstruction(const PHINode *Inst) {
     unsigned NumValues = Inst->getNumIncomingValues();
     Ice::InstPhi *IcePhi =
-        Ice::InstPhi::create(Func, NumValues, mapValueToIceVar(Inst));
+        Ice::InstPhi::create(Func.get(), NumValues, mapValueToIceVar(Inst));
     for (unsigned N = 0, E = NumValues; N != E; ++N) {
       IcePhi->addArgument(convertOperand(Inst, N),
                           mapBasicBlockToNode(Inst->getIncomingBlock(N)));
@@ -340,31 +339,31 @@ private:
       BasicBlock *BBElse = Inst->getSuccessor(1);
       Ice::CfgNode *NodeThen = mapBasicBlockToNode(BBThen);
       Ice::CfgNode *NodeElse = mapBasicBlockToNode(BBElse);
-      return Ice::InstBr::create(Func, Src, NodeThen, NodeElse);
+      return Ice::InstBr::create(Func.get(), Src, NodeThen, NodeElse);
     } else {
       BasicBlock *BBSucc = Inst->getSuccessor(0);
-      return Ice::InstBr::create(Func, mapBasicBlockToNode(BBSucc));
+      return Ice::InstBr::create(Func.get(), mapBasicBlockToNode(BBSucc));
     }
   }
 
   Ice::Inst *convertIntToPtrInstruction(const IntToPtrInst *Inst) {
     Ice::Operand *Src = convertOperand(Inst, 0);
     Ice::Variable *Dest = mapValueToIceVar(Inst, Ice::getPointerType());
-    return Ice::InstAssign::create(Func, Dest, Src);
+    return Ice::InstAssign::create(Func.get(), Dest, Src);
   }
 
   Ice::Inst *convertPtrToIntInstruction(const PtrToIntInst *Inst) {
     Ice::Operand *Src = convertOperand(Inst, 0);
     Ice::Variable *Dest = mapValueToIceVar(Inst);
-    return Ice::InstAssign::create(Func, Dest, Src);
+    return Ice::InstAssign::create(Func.get(), Dest, Src);
   }
 
   Ice::Inst *convertRetInstruction(const ReturnInst *Inst) {
     Ice::Operand *RetOperand = convertOperand(Inst, 0);
     if (RetOperand) {
-      return Ice::InstRet::create(Func, RetOperand);
+      return Ice::InstRet::create(Func.get(), RetOperand);
     } else {
-      return Ice::InstRet::create(Func);
+      return Ice::InstRet::create(Func.get());
     }
   }
 
@@ -372,7 +371,7 @@ private:
                                     Ice::InstCast::OpKind CastKind) {
     Ice::Operand *Src = convertOperand(Inst, 0);
     Ice::Variable *Dest = mapValueToIceVar(Inst);
-    return Ice::InstCast::create(Func, CastKind, Dest, Src);
+    return Ice::InstCast::create(Func.get(), CastKind, Dest, Src);
   }
 
   Ice::Inst *convertICmpInstruction(const ICmpInst *Inst) {
@@ -416,7 +415,7 @@ private:
       break;
     }
 
-    return Ice::InstIcmp::create(Func, Cond, Dest, Src0, Src1);
+    return Ice::InstIcmp::create(Func.get(), Cond, Dest, Src0, Src1);
   }
 
   Ice::Inst *convertFCmpInstruction(const FCmpInst *Inst) {
@@ -480,14 +479,14 @@ private:
       break;
     }
 
-    return Ice::InstFcmp::create(Func, Cond, Dest, Src0, Src1);
+    return Ice::InstFcmp::create(Func.get(), Cond, Dest, Src0, Src1);
   }
 
   Ice::Inst *convertExtractElementInstruction(const ExtractElementInst *Inst) {
     Ice::Variable *Dest = mapValueToIceVar(Inst);
     Ice::Operand *Source1 = convertValue(Inst->getOperand(0));
     Ice::Operand *Source2 = convertValue(Inst->getOperand(1));
-    return Ice::InstExtractElement::create(Func, Dest, Source1, Source2);
+    return Ice::InstExtractElement::create(Func.get(), Dest, Source1, Source2);
   }
 
   Ice::Inst *convertInsertElementInstruction(const InsertElementInst *Inst) {
@@ -495,7 +494,7 @@ private:
     Ice::Operand *Source1 = convertValue(Inst->getOperand(0));
     Ice::Operand *Source2 = convertValue(Inst->getOperand(1));
     Ice::Operand *Source3 = convertValue(Inst->getOperand(2));
-    return Ice::InstInsertElement::create(Func, Dest, Source1, Source2,
+    return Ice::InstInsertElement::create(Func.get(), Dest, Source1, Source2,
                                           Source3);
   }
 
@@ -504,7 +503,7 @@ private:
     Ice::Operand *Cond = convertValue(Inst->getCondition());
     Ice::Operand *Source1 = convertValue(Inst->getTrueValue());
     Ice::Operand *Source2 = convertValue(Inst->getFalseValue());
-    return Ice::InstSelect::create(Func, Dest, Cond, Source1, Source2);
+    return Ice::InstSelect::create(Func.get(), Dest, Cond, Source1, Source2);
   }
 
   Ice::Inst *convertSwitchInstruction(const SwitchInst *Inst) {
@@ -512,7 +511,7 @@ private:
     Ice::CfgNode *LabelDefault = mapBasicBlockToNode(Inst->getDefaultDest());
     unsigned NumCases = Inst->getNumCases();
     Ice::InstSwitch *Switch =
-        Ice::InstSwitch::create(Func, NumCases, Source, LabelDefault);
+        Ice::InstSwitch::create(Func.get(), NumCases, Source, LabelDefault);
     unsigned CurrentCase = 0;
     for (SwitchInst::ConstCaseIt I = Inst->case_begin(), E = Inst->case_end();
          I != E; ++I, ++CurrentCase) {
@@ -544,14 +543,14 @@ private:
           report_fatal_error(std::string("Invalid PNaCl intrinsic call: ") +
                              LLVMObjectAsString(Inst));
         }
-        NewInst = Ice::InstIntrinsicCall::create(Func, NumArgs, Dest,
+        NewInst = Ice::InstIntrinsicCall::create(Func.get(), NumArgs, Dest,
                                                  CallTarget, Info->Info);
       }
     }
 
     // Not an intrinsic call.
     if (NewInst == nullptr) {
-      NewInst = Ice::InstCall::create(Func, NumArgs, Dest, CallTarget,
+      NewInst = Ice::InstCall::create(Func.get(), NumArgs, Dest, CallTarget,
                                       Inst->isTailCall());
     }
     for (unsigned i = 0; i < NumArgs; ++i) {
@@ -569,11 +568,11 @@ private:
     uint32_t Align = Inst->getAlignment();
     Ice::Variable *Dest = mapValueToIceVar(Inst, Ice::getPointerType());
 
-    return Ice::InstAlloca::create(Func, ByteCount, Align, Dest);
+    return Ice::InstAlloca::create(Func.get(), ByteCount, Align, Dest);
   }
 
   Ice::Inst *convertUnreachableInstruction(const UnreachableInst * /*Inst*/) {
-    return Ice::InstUnreachable::create(Func);
+    return Ice::InstUnreachable::create(Func.get());
   }
 
   Ice::CfgNode *convertBasicBlock(const BasicBlock *BB) {
@@ -621,7 +620,7 @@ private:
 
 private:
   // Data
-  Ice::Cfg *Func;
+  std::unique_ptr<Ice::Cfg> Func;
   std::map<const Value *, Ice::Variable *> VarMap;
   std::map<const BasicBlock *, Ice::CfgNode *> NodeMap;
 };
@@ -884,8 +883,8 @@ void Converter::convertFunctions() {
     }
     LLVM2ICEFunctionConverter FunctionConverter(*this);
 
-    Cfg *Fcn = FunctionConverter.convertFunction(&I);
-    translateFcn(Fcn);
+    std::unique_ptr<Cfg> Fcn = FunctionConverter.convertFunction(&I);
+    translateFcn(std::move(Fcn));

[Karl, 2015/02/02 18:14:10]

Should you leave the ownership of Func inside FunctionConvert, and have it
explicitly release the pointer to pass to TranslateFcn (cleaning up how owns the
unique_ptr?).

[Jim Stichnoth, 2015/02/02 18:48:48]

Done.

     if (ALLOW_DUMP && Ctx->getFlags().TimeEachFunction)
       Ctx->popTimer(TimerID, StackID);
   }