Remove block address constants form PNaCl bitcode.

Removes block address constants because they are not part of the PNaClABI.
Suggested in CL https://codereview.chromium.org/20172002

BUG= https://code.google.com/p/nativeclient/issues/detail?id=3590
R=mseaborn@chromium.org

Review URL: https://codereview.chromium.org/20402002

6 files changed, 1 insertions, 114 deletions

diff --git a/include/llvm/Bitcode/NaCl/NaClLLVMBitCodes.h b/include/llvm/Bitcode/NaCl/NaClLLVMBitCodes.h
index b334842415..53f74f0ef4 100644
--- a/include/llvm/Bitcode/NaCl/NaClLLVMBitCodes.h
+++ b/include/llvm/Bitcode/NaCl/NaClLLVMBitCodes.h
@@ -162,7 +162,7 @@ namespace naclbitc {
     CST_CODE_INLINEASM_OLD = 18,  // No longer used.
     CST_CODE_CE_SHUFVEC_EX = 19,  // Not used in PNaCl.
     CST_CODE_CE_INBOUNDS_GEP = 20,// Not used in PNaCl.
-    CST_CODE_BLOCKADDRESS  = 21,  // CST_CODE_BLOCKADDRESS [fnty, fnval, bb#]
+    CST_CODE_BLOCKADDRESS  = 21,  // Not used in PNaCl.
     CST_CODE_DATA          = 22,  // DATA:          [n x elements]
     CST_CODE_INLINEASM     = 23   // Not used in PNaCl.
   };
diff --git a/lib/Bitcode/NaCl/Reader/NaClBitcodeReader.cpp b/lib/Bitcode/NaCl/Reader/NaClBitcodeReader.cpp
index f36fc4b17c..b384df7f58 100644
--- a/lib/Bitcode/NaCl/Reader/NaClBitcodeReader.cpp
+++ b/lib/Bitcode/NaCl/Reader/NaClBitcodeReader.cpp
@@ -33,13 +33,6 @@ enum {
   SWITCH_INST_MAGIC = 0x4B5 // May 2012 => 1205 => Hex
 };
 
-void NaClBitcodeReader::materializeForwardReferencedFunctions() {
-  while (!BlockAddrFwdRefs.empty()) {
-    Function *F = BlockAddrFwdRefs.begin()->first;
-    F->Materialize();
-  }
-}
-
 void NaClBitcodeReader::FreeState() {
   if (BufferOwned)
     delete Buffer;
@@ -50,8 +43,6 @@ void NaClBitcodeReader::FreeState() {
   std::vector<BasicBlock*>().swap(FunctionBBs);
   std::vector<Function*>().swap(FunctionsWithBodies);
   DeferredFunctionInfo.clear();
-
-  assert(BlockAddrFwdRefs.empty() && "Unresolved blockaddress fwd references");
 }
 
 //===----------------------------------------------------------------------===//
@@ -1014,37 +1005,6 @@ bool NaClBitcodeReader::ParseConstants() {
       }
       break;
     }
-
-    case naclbitc::CST_CODE_BLOCKADDRESS:{
-      if (Record.size() < 3) return Error("Invalid CE_BLOCKADDRESS record");
-      Type *FnTy = getTypeByID(Record[0]);
-      if (FnTy == 0) return Error("Invalid CE_BLOCKADDRESS record");
-      Function *Fn =
-        dyn_cast_or_null<Function>(ValueList.getConstantFwdRef(Record[1],FnTy));
-      if (Fn == 0) return Error("Invalid CE_BLOCKADDRESS record");
-
-      // If the function is already parsed we can insert the block address right
-      // away.
-      if (!Fn->empty()) {
-        Function::iterator BBI = Fn->begin(), BBE = Fn->end();
-        for (size_t I = 0, E = Record[2]; I != E; ++I) {
-          if (BBI == BBE)
-            return Error("Invalid blockaddress block #");
-          ++BBI;
-        }
-        V = BlockAddress::get(Fn, BBI);
-      } else {
-        // Otherwise insert a placeholder and remember it so it can be inserted
-        // when the function is parsed.
-        GlobalVariable *FwdRef = new GlobalVariable(*Fn->getParent(),
-                                                    Type::getInt8Ty(Context),
-                                            false, GlobalValue::InternalLinkage,
-                                                    0, "");
-        BlockAddrFwdRefs[Fn].push_back(std::make_pair(Record[2], FwdRef));
-        V = FwdRef;
-      }
-      break;
-    }
     }
 
     ValueList.AssignValue(V, NextCstNo);
@@ -1782,25 +1742,6 @@ OutOfRecordLoop:
     }
   }
 
-  // See if anything took the address of blocks in this function.  If so,
-  // resolve them now.
-  DenseMap<Function*, std::vector<BlockAddrRefTy> >::iterator BAFRI =
-    BlockAddrFwdRefs.find(F);
-  if (BAFRI != BlockAddrFwdRefs.end()) {
-    std::vector<BlockAddrRefTy> &RefList = BAFRI->second;
-    for (unsigned i = 0, e = RefList.size(); i != e; ++i) {
-      unsigned BlockIdx = RefList[i].first;
-      if (BlockIdx >= FunctionBBs.size())
-        return Error("Invalid blockaddress block #");
-
-      GlobalVariable *FwdRef = RefList[i].second;
-      FwdRef->replaceAllUsesWith(BlockAddress::get(F, FunctionBBs[BlockIdx]));
-      FwdRef->eraseFromParent();
-    }
-
-    BlockAddrFwdRefs.erase(BAFRI);
-  }
-
   // Trim the value list down to the size it was before we parsed this function.
   ValueList.shrinkTo(ModuleValueListSize);
   std::vector<BasicBlock*>().swap(FunctionBBs);
@@ -1873,16 +1814,6 @@ bool NaClBitcodeReader::isDematerializable(const GlobalValue *GV) const {
   const Function *F = dyn_cast<Function>(GV);
   if (!F || F->isDeclaration())
     return false;
-  // @LOCALMOD-START
-  // Don't dematerialize functions with BBs which have their address taken;
-  // it will cause any referencing blockAddress constants to also be destroyed,
-  // but because they are GVs, they need to stay around until PassManager
-  // finalization.
-  for (Function::const_iterator BB = F->begin(); BB != F->end(); ++BB) {
-    if (BB->hasAddressTaken())
-      return false;
-  }
-  // @LOCALMOD-END
   return DeferredFunctionInfo.count(const_cast<Function*>(F));
 }
 
@@ -1993,8 +1924,6 @@ Module *llvm::getNaClLazyBitcodeModule(MemoryBuffer *Buffer,
   // Have the NaClBitcodeReader dtor delete 'Buffer'.
   R->setBufferOwned(true);
 
-  R->materializeForwardReferencedFunctions();
-
   return M;
 }
 
@@ -2016,8 +1945,6 @@ Module *llvm::getNaClStreamedBitcodeModule(const std::string &name,
   }
   R->setBufferOwned(false); // no buffer to delete
 
-  R->materializeForwardReferencedFunctions();
-
   return M;
 }
 
diff --git a/lib/Bitcode/NaCl/Reader/NaClBitcodeReader.h b/lib/Bitcode/NaCl/Reader/NaClBitcodeReader.h
index fe7b5c1e9e..849ca7e506 100644
--- a/lib/Bitcode/NaCl/Reader/NaClBitcodeReader.h
+++ b/lib/Bitcode/NaCl/Reader/NaClBitcodeReader.h
@@ -155,11 +155,6 @@ class NaClBitcodeReader : public GVMaterializer {
   /// stream.
   DenseMap<Function*, uint64_t> DeferredFunctionInfo;
 
-  /// BlockAddrFwdRefs - These are blockaddr references to basic blocks.  These
-  /// are resolved lazily when functions are loaded.
-  typedef std::pair<unsigned, GlobalVariable*> BlockAddrRefTy;
-  DenseMap<Function*, std::vector<BlockAddrRefTy> > BlockAddrFwdRefs;
-
   /// UseRelativeIDs - Indicates that we are using a new encoding for
   /// instruction operands where most operands in the current
   /// FUNCTION_BLOCK are encoded relative to the instruction number,
@@ -193,8 +188,6 @@ public:
     FreeState();
   }
 
-  void materializeForwardReferencedFunctions();
-
   void FreeState();
 
   /// setBufferOwned - If this is true, the reader will destroy the MemoryBuffer
diff --git a/lib/Bitcode/NaCl/Writer/NaClBitcodeWriter.cpp b/lib/Bitcode/NaCl/Writer/NaClBitcodeWriter.cpp
index afc8d83451..9f3626557b 100644
--- a/lib/Bitcode/NaCl/Writer/NaClBitcodeWriter.cpp
+++ b/lib/Bitcode/NaCl/Writer/NaClBitcodeWriter.cpp
@@ -753,11 +753,6 @@ static void WriteConstants(unsigned FirstVal, unsigned LastVal,
       for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
         Record.push_back(VE.getValueID(C->getOperand(i)));
       AbbrevToUse = AggregateAbbrev;
-    } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
-      Code = naclbitc::CST_CODE_BLOCKADDRESS;
-      Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
-      Record.push_back(VE.getValueID(BA->getFunction()));
-      Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
     } else {
 #ifndef NDEBUG
       C->dump();
diff --git a/lib/Bitcode/NaCl/Writer/NaClValueEnumerator.cpp b/lib/Bitcode/NaCl/Writer/NaClValueEnumerator.cpp
index 01b4ff8df5..3ad224a04f 100644
--- a/lib/Bitcode/NaCl/Writer/NaClValueEnumerator.cpp
+++ b/lib/Bitcode/NaCl/Writer/NaClValueEnumerator.cpp
@@ -423,22 +423,3 @@ void NaClValueEnumerator::purgeFunction() {
   BasicBlocks.clear();
   FnForwardTypeRefs.clear();
 }
-
-static void IncorporateFunctionInfoGlobalBBIDs(const Function *F,
-                                 DenseMap<const BasicBlock*, unsigned> &IDMap) {
-  unsigned Counter = 0;
-  for (Function::const_iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
-    IDMap[BB] = ++Counter;
-}
-
-/// getGlobalBasicBlockID - This returns the function-specific ID for the
-/// specified basic block.  This is relatively expensive information, so it
-/// should only be used by rare constructs such as address-of-label.
-unsigned NaClValueEnumerator::getGlobalBasicBlockID(const BasicBlock *BB) const {
-  unsigned &Idx = GlobalBasicBlockIDs[BB];
-  if (Idx != 0)
-    return Idx-1;
-
-  IncorporateFunctionInfoGlobalBBIDs(BB->getParent(), GlobalBasicBlockIDs);
-  return getGlobalBasicBlockID(BB);
-}
diff --git a/lib/Bitcode/NaCl/Writer/NaClValueEnumerator.h b/lib/Bitcode/NaCl/Writer/NaClValueEnumerator.h
index 21bbb2fb76..3e71740f92 100644
--- a/lib/Bitcode/NaCl/Writer/NaClValueEnumerator.h
+++ b/lib/Bitcode/NaCl/Writer/NaClValueEnumerator.h
@@ -55,10 +55,6 @@ private:
   ValueMapType ValueMap;
   ValueList Values;
 
-  /// GlobalBasicBlockIDs - This map memoizes the basic block ID's referenced by
-  /// the "getGlobalBasicBlockID" method.
-  mutable DenseMap<const BasicBlock*, unsigned> GlobalBasicBlockIDs;
-
   typedef DenseMap<const Instruction*, unsigned> InstructionMapType;
   InstructionMapType InstructionMap;
   unsigned InstructionCount;
@@ -133,11 +129,6 @@ public:
     return BasicBlocks;
   }
 
-  /// getGlobalBasicBlockID - This returns the function-specific ID for the
-  /// specified basic block.  This is relatively expensive information, so it
-  /// should only be used by rare constructs such as address-of-label.
-  unsigned getGlobalBasicBlockID(const BasicBlock *BB) const;
-
   /// incorporateFunction/purgeFunction - If you'd like to deal with a function,
   /// use these two methods to get its data into the NaClValueEnumerator!
   ///