Update LLVM to r84949.

7 files changed, 542 insertions, 160 deletions

diff --git a/utils/TableGen/AsmWriterEmitter.cpp b/utils/TableGen/AsmWriterEmitter.cpp
index 84a647b..ff348e8 100644
--- a/utils/TableGen/AsmWriterEmitter.cpp
+++ b/utils/TableGen/AsmWriterEmitter.cpp
@@ -538,6 +538,29 @@ FindUniqueOperandCommands(std::vector<std::string> &UniqueOperandCommands,
 }
 
 
+static void UnescapeString(std::string &Str) {
+  for (unsigned i = 0; i != Str.size(); ++i) {
+    if (Str[i] == '\\' && i != Str.size()-1) {
+      switch (Str[i+1]) {
+      default: continue;  // Don't execute the code after the switch.
+      case 'a': Str[i] = '\a'; break;
+      case 'b': Str[i] = '\b'; break;
+      case 'e': Str[i] = 27; break;
+      case 'f': Str[i] = '\f'; break;
+      case 'n': Str[i] = '\n'; break;
+      case 'r': Str[i] = '\r'; break;
+      case 't': Str[i] = '\t'; break;
+      case 'v': Str[i] = '\v'; break;
+      case '"': Str[i] = '\"'; break;
+      case '\'': Str[i] = '\''; break;
+      case '\\': Str[i] = '\\'; break;
+      }
+      // Nuke the second character.
+      Str.erase(Str.begin()+i+1);
+    }
+  }
+}
+
 /// EmitPrintInstruction - Generate the code for the "printInstruction" method
 /// implementation.
 void AsmWriterEmitter::EmitPrintInstruction(raw_ostream &O) {
diff --git a/utils/TableGen/ClangDiagnosticsEmitter.cpp b/utils/TableGen/ClangDiagnosticsEmitter.cpp
index c127afd..6f1080e 100644
--- a/utils/TableGen/ClangDiagnosticsEmitter.cpp
+++ b/utils/TableGen/ClangDiagnosticsEmitter.cpp
@@ -52,15 +52,12 @@ void ClangDiagsDefsEmitter::run(raw_ostream &OS) {
     
     // Description string.
     OS << ", \"";
-    std::string S = R.getValueAsString("Text");
-    EscapeString(S);
-    OS << S << "\"";
+    OS.write_escaped(R.getValueAsString("Text")) << '"';
     
     // Warning associated with the diagnostic.
     if (DefInit *DI = dynamic_cast<DefInit*>(R.getValueInit("Group"))) {
-      S = DI->getDef()->getValueAsString("GroupName");
-      EscapeString(S);
-      OS << ", \"" << S << "\"";
+      OS << ", \"";
+      OS.write_escaped(DI->getDef()->getValueAsString("GroupName")) << '"';
     } else {
       OS << ", 0";
     }
@@ -151,11 +148,10 @@ void ClangDiagGroupsEmitter::run(raw_ostream &OS) {
   OS << "\n#ifdef GET_DIAG_TABLE\n";
   for (std::map<std::string, GroupInfo>::iterator
        I = DiagsInGroup.begin(), E = DiagsInGroup.end(); I != E; ++I) {
-    std::string S = I->first;
-    EscapeString(S);
     // Group option string.
-    OS << "  { \"" << S << "\","
-      << std::string(MaxLen-I->first.size()+1, ' ');
+    OS << "  { \"";
+    OS.write_escaped(I->first) << "\","
+                               << std::string(MaxLen-I->first.size()+1, ' ');
     
     // Diagnostics in the group.
     if (I->second.DiagsInGroup.empty())
diff --git a/utils/TableGen/CodeGenDAGPatterns.h b/utils/TableGen/CodeGenDAGPatterns.h
index 9b53ecc5..398764b 100644
--- a/utils/TableGen/CodeGenDAGPatterns.h
+++ b/utils/TableGen/CodeGenDAGPatterns.h
@@ -584,6 +584,8 @@ public:
     return intrinsic_wo_chain_sdnode;
   }
   
+  bool hasTargetIntrinsics() { return !TgtIntrinsics.empty(); }
+
 private:
   void ParseNodeInfo();
   void ParseNodeTransforms();
diff --git a/utils/TableGen/DAGISelEmitter.cpp b/utils/TableGen/DAGISelEmitter.cpp
index dcf64e4..bbb8a18 100644
--- a/utils/TableGen/DAGISelEmitter.cpp
+++ b/utils/TableGen/DAGISelEmitter.cpp
@@ -2067,8 +2067,16 @@ void DAGISelEmitter::EmitInstructionSelector(raw_ostream &OS) {
      << "  errs() << \"Cannot yet select: \";\n"
      << "  unsigned iid = cast<ConstantSDNode>(N.getOperand("
      << "N.getOperand(0).getValueType() == MVT::Other))->getZExtValue();\n"
-     << " llvm_report_error(\"Cannot yet select: intrinsic %\" +\n"
-     << "Intrinsic::getName((Intrinsic::ID)iid));\n"
+     << "  if (iid < Intrinsic::num_intrinsics)\n"
+     << "    llvm_report_error(\"Cannot yet select: intrinsic %\" + "
+     << "Intrinsic::getName((Intrinsic::ID)iid));\n";
+  if (CGP.hasTargetIntrinsics()) {
+    OS << "  else if (const TargetIntrinsicInfo *tii = TM.getIntrinsicInfo())\n"
+       << "    llvm_report_error(Twine(\"Cannot yet select: target intrinsic "
+       << "%\") + tii->getName(iid));\n";
+  }
+  OS << "  else\n"
+     << "    llvm_report_error(\"Cannot yet select: invalid intrinsic\");\n"
      << "}\n\n";
 }
 
diff --git a/utils/TableGen/LLVMCConfigurationEmitter.cpp b/utils/TableGen/LLVMCConfigurationEmitter.cpp
index 06afaf7..f5d1139 100644
--- a/utils/TableGen/LLVMCConfigurationEmitter.cpp
+++ b/utils/TableGen/LLVMCConfigurationEmitter.cpp
@@ -56,8 +56,14 @@ const char * SinkOptionName = "AutoGeneratedSinkOption";
 
 /// Id - An 'identity' function object.
 struct Id {
-  template<typename T>
-  void operator()(const T&) const {
+  template<typename T0>
+  void operator()(const T0&) const {
+  }
+  template<typename T0, typename T1>
+  void operator()(const T0&, const T1&) const {
+  }
+  template<typename T0, typename T1, typename T2>
+  void operator()(const T0&, const T1&, const T2&) const {
   }
 };
 
@@ -81,16 +87,24 @@ const DagInit& InitPtrToDag(const Init* ptr) {
   return val;
 }
 
+const std::string GetOperatorName(const DagInit* D) {
+  return D->getOperator()->getAsString();
+}
+
+const std::string GetOperatorName(const DagInit& D) {
+  return GetOperatorName(&D);
+}
+
 // checkNumberOfArguments - Ensure that the number of args in d is
 // greater than or equal to min_arguments, otherwise throw an exception.
 void checkNumberOfArguments (const DagInit* d, unsigned min_arguments) {
   if (!d || d->getNumArgs() < min_arguments)
-    throw d->getOperator()->getAsString() + ": too few arguments!";
+    throw GetOperatorName(d) + ": too few arguments!";
 }
 
 // isDagEmpty - is this DAG marked with an empty marker?
 bool isDagEmpty (const DagInit* d) {
-  return d->getOperator()->getAsString() == "empty_dag_marker";
+  return GetOperatorName(d) == "empty_dag_marker";
 }
 
 // EscapeVariableName - Escape commas and other symbols not allowed
@@ -132,6 +146,18 @@ void checkedIncrement(I& P, I E, S ErrorString) {
     throw ErrorString;
 }
 
+// apply is needed because C++'s syntax doesn't let us construct a function
+// object and call it in the same statement.
+template<typename F, typename T0>
+void apply(F Fun, T0& Arg0) {
+  return Fun(Arg0);
+}
+
+template<typename F, typename T0, typename T1>
+void apply(F Fun, T0& Arg0, T1& Arg1) {
+  return Fun(Arg0, Arg1);
+}
+
 //===----------------------------------------------------------------------===//
 /// Back-end specific code
 
@@ -143,6 +169,10 @@ namespace OptionType {
   enum OptionType { Alias, Switch, Parameter, ParameterList,
                     Prefix, PrefixList};
 
+  bool IsAlias(OptionType t) {
+    return (t == Alias);
+  }
+
   bool IsList (OptionType t) {
     return (t == ParameterList || t == PrefixList);
   }
@@ -231,12 +261,12 @@ struct OptionDescription {
   bool isReallyHidden() const;
   void setReallyHidden();
 
-  bool isParameter() const
-  { return OptionType::IsParameter(this->Type); }
-
   bool isSwitch() const
   { return OptionType::IsSwitch(this->Type); }
 
+  bool isParameter() const
+  { return OptionType::IsParameter(this->Type); }
+
   bool isList() const
   { return OptionType::IsList(this->Type); }
 
@@ -258,7 +288,7 @@ void OptionDescription::Merge (const OptionDescription& other)
 }
 
 bool OptionDescription::isAlias() const {
-  return Type == OptionType::Alias;
+  return OptionType::IsAlias(this->Type);
 }
 
 bool OptionDescription::isMultiVal() const {
@@ -352,6 +382,14 @@ public:
   /// FindOption - exception-throwing wrapper for find().
   const OptionDescription& FindOption(const std::string& OptName) const;
 
+  // Wrappers for FindOption that throw an exception in case the option has a
+  // wrong type.
+  const OptionDescription& FindSwitch(const std::string& OptName) const;
+  const OptionDescription& FindParameter(const std::string& OptName) const;
+  const OptionDescription& FindList(const std::string& OptName) const;
+  const OptionDescription&
+  FindListOrParameter(const std::string& OptName) const;
+
   /// insertDescription - Insert new OptionDescription into
   /// OptionDescriptions list
   void InsertDescription (const OptionDescription& o);
@@ -363,8 +401,7 @@ public:
 };
 
 const OptionDescription&
-OptionDescriptions::FindOption(const std::string& OptName) const
-{
+OptionDescriptions::FindOption(const std::string& OptName) const {
   const_iterator I = Descriptions.find(OptName);
   if (I != Descriptions.end())
     return I->second;
@@ -372,8 +409,40 @@ OptionDescriptions::FindOption(const std::string& OptName) const
     throw OptName + ": no such option!";
 }
 
-void OptionDescriptions::InsertDescription (const OptionDescription& o)
-{
+const OptionDescription&
+OptionDescriptions::FindSwitch(const std::string& OptName) const {
+  const OptionDescription& OptDesc = this->FindOption(OptName);
+  if (!OptDesc.isSwitch())
+    throw OptName + ": incorrect option type - should be a switch!";
+  return OptDesc;
+}
+
+const OptionDescription&
+OptionDescriptions::FindList(const std::string& OptName) const {
+  const OptionDescription& OptDesc = this->FindOption(OptName);
+  if (!OptDesc.isList())
+    throw OptName + ": incorrect option type - should be a list!";
+  return OptDesc;
+}
+
+const OptionDescription&
+OptionDescriptions::FindParameter(const std::string& OptName) const {
+  const OptionDescription& OptDesc = this->FindOption(OptName);
+  if (!OptDesc.isParameter())
+    throw OptName + ": incorrect option type - should be a parameter!";
+  return OptDesc;
+}
+
+const OptionDescription&
+OptionDescriptions::FindListOrParameter(const std::string& OptName) const {
+  const OptionDescription& OptDesc = this->FindOption(OptName);
+  if (!OptDesc.isList() && !OptDesc.isParameter())
+    throw OptName
+      + ": incorrect option type - should be a list or parameter!";
+  return OptDesc;
+}
+
+void OptionDescriptions::InsertDescription (const OptionDescription& o) {
   container_type::iterator I = Descriptions.find(o.Name);
   if (I != Descriptions.end()) {
     OptionDescription& D = I->second;
@@ -409,7 +478,7 @@ public:
   /// handler.
   void operator() (Init* i) {
     const DagInit& property = InitPtrToDag(i);
-    const std::string& property_name = property.getOperator()->getAsString();
+    const std::string& property_name = GetOperatorName(property);
     typename HandlerMap::iterator method = Handlers_.find(property_name);
 
     if (method != Handlers_.end()) {
@@ -558,7 +627,7 @@ public:
     checkNumberOfArguments(&d, 1);
 
     const OptionType::OptionType Type =
-      stringToOptionType(d.getOperator()->getAsString());
+      stringToOptionType(GetOperatorName(d));
     const std::string& Name = InitPtrToString(d.getArg(0));
 
     OptionDescription OD(Type, Name);
@@ -678,7 +747,7 @@ private:
     checkNumberOfArguments(d, 1);
     Init* Case = d->getArg(0);
     if (typeid(*Case) != typeid(DagInit) ||
-        static_cast<DagInit*>(Case)->getOperator()->getAsString() != "case")
+        GetOperatorName(static_cast<DagInit*>(Case)) != "case")
       throw
         std::string("The argument to (actions) should be a 'case' construct!");
     toolDesc_.Actions = Case;
@@ -775,11 +844,17 @@ void FillInEdgeVector(RecordVector::const_iterator B,
 /// CalculatePriority - Calculate the priority of this plugin.
 int CalculatePriority(RecordVector::const_iterator B,
                       RecordVector::const_iterator E) {
-  int total = 0;
-  for (; B!=E; ++B) {
-    total += static_cast<int>((*B)->getValueAsInt("priority"));
+  int priority = 0;
+
+  if (B != E) {
+    priority  = static_cast<int>((*B)->getValueAsInt("priority"));
+
+    if (++B != E)
+      throw std::string("More than one 'PluginPriority' instance found: "
+                        "most probably an error!");
   }
-  return total;
+
+  return priority;
 }
 
 /// NotInGraph - Helper function object for FilterNotInGraph.
@@ -874,22 +949,60 @@ void TypecheckGraph (const RecordVector& EdgeVector,
 /// WalkCase - Walks the 'case' expression DAG and invokes
 /// TestCallback on every test, and StatementCallback on every
 /// statement. Handles 'case' nesting, but not the 'and' and 'or'
-/// combinators.
-// TODO: Re-implement EmitCaseConstructHandler on top of this function?
+/// combinators (that is, they are passed directly to TestCallback).
+/// TestCallback must have type 'void TestCallback(const DagInit*, unsigned
+/// IndentLevel, bool FirstTest)'.
+/// StatementCallback must have type 'void StatementCallback(const Init*,
+/// unsigned IndentLevel)'.
 template <typename F1, typename F2>
-void WalkCase(Init* Case, F1 TestCallback, F2 StatementCallback) {
+void WalkCase(const Init* Case, F1 TestCallback, F2 StatementCallback,
+              unsigned IndentLevel = 0)
+{
   const DagInit& d = InitPtrToDag(Case);
+
+  // Error checks.
+  if (GetOperatorName(d) != "case")
+    throw std::string("WalkCase should be invoked only on 'case' expressions!");
+
+  if (d.getNumArgs() < 2)
+    throw "There should be at least one clause in the 'case' expression:\n"
+      + d.getAsString();
+
+  // Main loop.
   bool even = false;
+  const unsigned numArgs = d.getNumArgs();
+  unsigned i = 1;
   for (DagInit::const_arg_iterator B = d.arg_begin(), E = d.arg_end();
        B != E; ++B) {
     Init* arg = *B;
-    if (even && dynamic_cast<DagInit*>(arg)
-        && static_cast<DagInit*>(arg)->getOperator()->getAsString() == "case")
-      WalkCase(arg, TestCallback, StatementCallback);
-    else if (!even)
-      TestCallback(arg);
+
+    if (!even)
+    {
+      // Handle test.
+      const DagInit& Test = InitPtrToDag(arg);
+
+      if (GetOperatorName(Test) == "default" && (i+1 != numArgs))
+        throw std::string("The 'default' clause should be the last in the"
+                          "'case' construct!");
+      if (i == numArgs)
+        throw "Case construct handler: no corresponding action "
+          "found for the test " + Test.getAsString() + '!';
+
+      TestCallback(&Test, IndentLevel, (i == 1));
+    }
     else
-      StatementCallback(arg);
+    {
+      if (dynamic_cast<DagInit*>(arg)
+          && GetOperatorName(static_cast<DagInit*>(arg)) == "case") {
+        // Nested 'case'.
+        WalkCase(arg, TestCallback, StatementCallback, IndentLevel + Indent1);
+      }
+
+      // Handle statement.
+      StatementCallback(arg, IndentLevel);
+    }
+
+    ++i;
     even = !even;
   }
 }
@@ -901,7 +1014,7 @@ class ExtractOptionNames {
 
   void processDag(const Init* Statement) {
     const DagInit& Stmt = InitPtrToDag(Statement);
-    const std::string& ActionName = Stmt.getOperator()->getAsString();
+    const std::string& ActionName = GetOperatorName(Stmt);
     if (ActionName == "forward" || ActionName == "forward_as" ||
         ActionName == "unpack_values" || ActionName == "switch_on" ||
         ActionName == "parameter_equals" || ActionName == "element_in_list" ||
@@ -932,6 +1045,13 @@ public:
       this->processDag(Statement);
     }
   }
+
+  void operator()(const DagInit* Test, unsigned, bool) {
+    this->operator()(Test);
+  }
+  void operator()(const Init* Statement, unsigned) {
+    this->operator()(Statement);
+  }
 };
 
 /// CheckForSuperfluousOptions - Check that there are no side
@@ -990,51 +1110,137 @@ bool EmitCaseTest0Args(const std::string& TestName, raw_ostream& O) {
   return false;
 }
 
+/// EmitListTest - Helper function used by EmitCaseTest1ArgList().
+template <typename F>
+void EmitListTest(const ListInit& L, const char* LogicOp,
+                  F Callback, raw_ostream& O)
+{
+  // This is a lot like EmitLogicalOperationTest, but works on ListInits instead
+  // of Dags...
+  bool isFirst = true;
+  for (ListInit::const_iterator B = L.begin(), E = L.end(); B != E; ++B) {
+    if (isFirst)
+      isFirst = false;
+    else
+      O << " || ";
+    Callback(InitPtrToString(*B), O);
+  }
+}
+
+// Callbacks for use with EmitListTest.
 
-/// EmitCaseTest1Arg - Helper function used by EmitCaseConstructHandler().
-bool EmitCaseTest1Arg(const std::string& TestName,
-                      const DagInit& d,
-                      const OptionDescriptions& OptDescs,
-                      raw_ostream& O) {
-  checkNumberOfArguments(&d, 1);
+class EmitSwitchOn {
+  const OptionDescriptions& OptDescs_;
+public:
+  EmitSwitchOn(const OptionDescriptions& OptDescs) : OptDescs_(OptDescs)
+  {}
+
+  void operator()(const std::string& OptName, raw_ostream& O) const {
+    const OptionDescription& OptDesc = OptDescs_.FindSwitch(OptName);
+    O << OptDesc.GenVariableName();
+  }
+};
+
+class EmitEmptyTest {
+  bool EmitNegate_;
+  const OptionDescriptions& OptDescs_;
+public:
+  EmitEmptyTest(bool EmitNegate, const OptionDescriptions& OptDescs)
+    : EmitNegate_(EmitNegate), OptDescs_(OptDescs)
+  {}
+
+  void operator()(const std::string& OptName, raw_ostream& O) const {
+    const char* Neg = (EmitNegate_ ? "!" : "");
+    if (OptName == "o") {
+      O << Neg << "OutputFilename.empty()";
+    }
+    else {
+      const OptionDescription& OptDesc = OptDescs_.FindListOrParameter(OptName);
+      O << Neg << OptDesc.GenVariableName() << ".empty()";
+    }
+  }
+};
+
+
+/// EmitCaseTest1ArgList - Helper function used by EmitCaseTest1Arg();
+bool EmitCaseTest1ArgList(const std::string& TestName,
+                          const DagInit& d,
+                          const OptionDescriptions& OptDescs,
+                          raw_ostream& O) {
+  const ListInit& L = *static_cast<ListInit*>(d.getArg(0));
+
+  if (TestName == "any_switch_on") {
+    EmitListTest(L, "||", EmitSwitchOn(OptDescs), O);
+    return true;
+  }
+  else if (TestName == "switch_on") {
+    EmitListTest(L, "&&", EmitSwitchOn(OptDescs), O);
+    return true;
+  }
+  else if (TestName == "any_not_empty") {
+    EmitListTest(L, "||", EmitEmptyTest(true, OptDescs), O);
+    return true;
+  }
+  else if (TestName == "any_empty") {
+    EmitListTest(L, "||", EmitEmptyTest(false, OptDescs), O);
+    return true;
+  }
+  else if (TestName == "not_empty") {
+    EmitListTest(L, "&&", EmitEmptyTest(true, OptDescs), O);
+    return true;
+  }
+  else if (TestName == "empty") {
+    EmitListTest(L, "&&", EmitEmptyTest(false, OptDescs), O);
+    return true;
+  }
+
+  return false;
+}
+
+/// EmitCaseTest1ArgStr - Helper function used by EmitCaseTest1Arg();
+bool EmitCaseTest1ArgStr(const std::string& TestName,
+                         const DagInit& d,
+                         const OptionDescriptions& OptDescs,
+                         raw_ostream& O) {
   const std::string& OptName = InitPtrToString(d.getArg(0));
 
   if (TestName == "switch_on") {
-    const OptionDescription& OptDesc = OptDescs.FindOption(OptName);
-    if (!OptDesc.isSwitch())
-      throw OptName + ": incorrect option type - should be a switch!";
-    O << OptDesc.GenVariableName();
+    apply(EmitSwitchOn(OptDescs), OptName, O);
     return true;
-  } else if (TestName == "input_languages_contain") {
+  }
+  else if (TestName == "input_languages_contain") {
     O << "InLangs.count(\"" << OptName << "\") != 0";
     return true;
-  } else if (TestName == "in_language") {
+  }
+  else if (TestName == "in_language") {
     // This works only for single-argument Tool::GenerateAction. Join
     // tools can process several files in different languages simultaneously.
 
     // TODO: make this work with Edge::Weight (if possible).
     O << "LangMap.GetLanguage(inFile) == \"" << OptName << '\"';
     return true;
-  } else if (TestName == "not_empty" || TestName == "empty") {
-    const char* Test = (TestName == "empty") ? "" : "!";
-
-    if (OptName == "o") {
-      O << Test << "OutputFilename.empty()";
-      return true;
-    }
-    else {
-      const OptionDescription& OptDesc = OptDescs.FindOption(OptName);
-      if (OptDesc.isSwitch())
-        throw OptName
-          + ": incorrect option type - should be a list or parameter!";
-      O << Test << OptDesc.GenVariableName() << ".empty()";
-      return true;
-    }
+  }
+  else if (TestName == "not_empty" || TestName == "empty") {
+    bool EmitNegate = (TestName == "not_empty");
+    apply(EmitEmptyTest(EmitNegate, OptDescs), OptName, O);
+    return true;
   }
 
   return false;
 }
 
+/// EmitCaseTest1Arg - Helper function used by EmitCaseConstructHandler();
+bool EmitCaseTest1Arg(const std::string& TestName,
+                      const DagInit& d,
+                      const OptionDescriptions& OptDescs,
+                      raw_ostream& O) {
+  checkNumberOfArguments(&d, 1);
+  if (typeid(*d.getArg(0)) == typeid(ListInit))
+    return EmitCaseTest1ArgList(TestName, d, OptDescs, O);
+  else
+    return EmitCaseTest1ArgStr(TestName, d, OptDescs, O);
+}
+
 /// EmitCaseTest2Args - Helper function used by EmitCaseConstructHandler().
 bool EmitCaseTest2Args(const std::string& TestName,
                        const DagInit& d,
@@ -1044,17 +1250,14 @@ bool EmitCaseTest2Args(const std::string& TestName,
   checkNumberOfArguments(&d, 2);
   const std::string& OptName = InitPtrToString(d.getArg(0));
   const std::string& OptArg = InitPtrToString(d.getArg(1));
-  const OptionDescription& OptDesc = OptDescs.FindOption(OptName);
 
   if (TestName == "parameter_equals") {
-    if (!OptDesc.isParameter())
-      throw OptName + ": incorrect option type - should be a parameter!";
+    const OptionDescription& OptDesc = OptDescs.FindParameter(OptName);
     O << OptDesc.GenVariableName() << " == \"" << OptArg << "\"";
     return true;
   }
   else if (TestName == "element_in_list") {
-    if (!OptDesc.isList())
-      throw OptName + ": incorrect option type - should be a list!";
+    const OptionDescription& OptDesc = OptDescs.FindList(OptName);
     const std::string& VarName = OptDesc.GenVariableName();
     O << "std::find(" << VarName << ".begin(),\n";
     O.indent(IndentLevel + Indent1)
@@ -1106,7 +1309,7 @@ void EmitLogicalNot(const DagInit& d, unsigned IndentLevel,
 void EmitCaseTest(const DagInit& d, unsigned IndentLevel,
                   const OptionDescriptions& OptDescs,
                   raw_ostream& O) {
-  const std::string& TestName = d.getOperator()->getAsString();
+  const std::string& TestName = GetOperatorName(d);
 
   if (TestName == "and")
     EmitLogicalOperationTest(d, "&&", IndentLevel, OptDescs, O);
@@ -1124,59 +1327,79 @@ void EmitCaseTest(const DagInit& d, unsigned IndentLevel,
     throw TestName + ": unknown edge property!";
 }
 
-// Emit code that handles the 'case' construct.
-// Takes a function object that should emit code for every case clause.
-// Callback's type is
-// void F(Init* Statement, unsigned IndentLevel, raw_ostream& O).
-template <typename F>
-void EmitCaseConstructHandler(const Init* Dag, unsigned IndentLevel,
-                              F Callback, bool EmitElseIf,
-                              const OptionDescriptions& OptDescs,
-                              raw_ostream& O) {
-  const DagInit* d = &InitPtrToDag(Dag);
-  if (d->getOperator()->getAsString() != "case")
-    throw std::string("EmitCaseConstructHandler should be invoked"
-                      " only on 'case' expressions!");
 
-  unsigned numArgs = d->getNumArgs();
-  if (d->getNumArgs() < 2)
-    throw "There should be at least one clause in the 'case' expression:\n"
-      + d->getAsString();
+/// EmitCaseTestCallback - Callback used by EmitCaseConstructHandler.
+class EmitCaseTestCallback {
+  bool EmitElseIf_;
+  const OptionDescriptions& OptDescs_;
+  raw_ostream& O_;
+public:
 
-  for (unsigned i = 0; i != numArgs; ++i) {
-    const DagInit& Test = InitPtrToDag(d->getArg(i));
+  EmitCaseTestCallback(bool EmitElseIf,
+                       const OptionDescriptions& OptDescs, raw_ostream& O)
+    : EmitElseIf_(EmitElseIf), OptDescs_(OptDescs), O_(O)
+  {}
 
-    // Emit the test.
-    if (Test.getOperator()->getAsString() == "default") {
-      if (i+2 != numArgs)
-        throw std::string("The 'default' clause should be the last in the"
-                          "'case' construct!");
-      O.indent(IndentLevel) << "else {\n";
+  void operator()(const DagInit* Test, unsigned IndentLevel, bool FirstTest)
+  {
+    if (GetOperatorName(Test) == "default") {
+      O_.indent(IndentLevel) << "else {\n";
     }
     else {
-      O.indent(IndentLevel) << ((i != 0 && EmitElseIf) ? "else if (" : "if (");
-      EmitCaseTest(Test, IndentLevel, OptDescs, O);
-      O << ") {\n";
+      O_.indent(IndentLevel)
+        << ((!FirstTest && EmitElseIf_) ? "else if (" : "if (");
+      EmitCaseTest(*Test, IndentLevel, OptDescs_, O_);
+      O_ << ") {\n";
     }
+  }
+};
 
-    // Emit the corresponding statement.
-    ++i;
-    if (i == numArgs)
-      throw "Case construct handler: no corresponding action "
-        "found for the test " + Test.getAsString() + '!';
-
-    Init* arg = d->getArg(i);
-    const DagInit* nd = dynamic_cast<DagInit*>(arg);
-    if (nd && (nd->getOperator()->getAsString() == "case")) {
-      // Handle the nested 'case'.
-      EmitCaseConstructHandler(nd, (IndentLevel + Indent1),
-                               Callback, EmitElseIf, OptDescs, O);
-    }
-    else {
-      Callback(arg, (IndentLevel + Indent1), O);
+/// EmitCaseStatementCallback - Callback used by EmitCaseConstructHandler.
+template <typename F>
+class EmitCaseStatementCallback {
+  F Callback_;
+  raw_ostream& O_;
+public:
+
+  EmitCaseStatementCallback(F Callback, raw_ostream& O)
+    : Callback_(Callback), O_(O)
+  {}
+
+  void operator() (const Init* Statement, unsigned IndentLevel) {
+
+    // Ignore nested 'case' DAG.
+    if (!(dynamic_cast<const DagInit*>(Statement) &&
+          GetOperatorName(static_cast<const DagInit*>(Statement)) == "case")) {
+      if (typeid(*Statement) == typeid(ListInit)) {
+        const ListInit& DagList = *static_cast<const ListInit*>(Statement);
+        for (ListInit::const_iterator B = DagList.begin(), E = DagList.end();
+             B != E; ++B)
+          Callback_(*B, (IndentLevel + Indent1), O_);
+      }
+      else {
+        Callback_(Statement, (IndentLevel + Indent1), O_);
+      }
     }
-    O.indent(IndentLevel) << "}\n";
+    O_.indent(IndentLevel) << "}\n";
   }
+
+};
+
+/// EmitCaseConstructHandler - Emit code that handles the 'case'
+/// construct. Takes a function object that should emit code for every case
+/// clause. Implemented on top of WalkCase.
+/// Callback's type is void F(Init* Statement, unsigned IndentLevel,
+/// raw_ostream& O).
+/// EmitElseIf parameter controls the type of condition that is emitted ('if
+/// (..) {..} else if (..) {} .. else {..}' vs. 'if (..) {..} if(..)  {..}
+/// .. else {..}').
+template <typename F>
+void EmitCaseConstructHandler(const Init* Case, unsigned IndentLevel,
+                              F Callback, bool EmitElseIf,
+                              const OptionDescriptions& OptDescs,
+                              raw_ostream& O) {
+  WalkCase(Case, EmitCaseTestCallback(EmitElseIf, OptDescs, O),
+           EmitCaseStatementCallback<F>(Callback, O), IndentLevel);
 }
 
 /// TokenizeCmdline - converts from "$CALL(HookName, 'Arg1', 'Arg2')/path" to
@@ -1474,17 +1697,40 @@ void EmitForwardOptionPropertyHandlingCode (const OptionDescription& D,
   }
 }
 
-/// EmitActionHandler - Emit code that handles actions. Used by
-/// EmitGenerateActionMethod() as an argument to
-/// EmitCaseConstructHandler().
-class EmitActionHandler {
+/// ActionHandlingCallbackBase - Base class of EmitActionHandlersCallback and
+/// EmitPreprocessOptionsCallback.
+struct ActionHandlingCallbackBase {
+
+  void onErrorDag(const DagInit& d,
+                  unsigned IndentLevel, raw_ostream& O) const
+  {
+    O.indent(IndentLevel)
+      << "throw std::runtime_error(\"" <<
+      (d.getNumArgs() >= 1 ? InitPtrToString(d.getArg(0))
+       : "Unknown error!")
+      << "\");\n";
+  }
+
+  void onWarningDag(const DagInit& d,
+                    unsigned IndentLevel, raw_ostream& O) const
+  {
+    checkNumberOfArguments(&d, 1);
+    O.indent(IndentLevel) << "llvm::errs() << \""
+                          << InitPtrToString(d.getArg(0)) << "\";\n";
+  }
+
+};
+
+/// EmitActionHandlersCallback - Emit code that handles actions. Used by
+/// EmitGenerateActionMethod() as an argument to EmitCaseConstructHandler().
+class EmitActionHandlersCallback : ActionHandlingCallbackBase {
   const OptionDescriptions& OptDescs;
 
   void processActionDag(const Init* Statement, unsigned IndentLevel,
                         raw_ostream& O) const
   {
     const DagInit& Dag = InitPtrToDag(Statement);
-    const std::string& ActionName = Dag.getOperator()->getAsString();
+    const std::string& ActionName = GetOperatorName(Dag);
 
     if (ActionName == "append_cmd") {
       checkNumberOfArguments(&Dag, 1);
@@ -1497,10 +1743,10 @@ class EmitActionHandler {
         O.indent(IndentLevel) << "vec.push_back(\"" << *B << "\");\n";
     }
     else if (ActionName == "error") {
-      O.indent(IndentLevel) << "throw std::runtime_error(\"" <<
-        (Dag.getNumArgs() >= 1 ? InitPtrToString(Dag.getArg(0))
-         : "Unknown error!")
-        << "\");\n";
+      this->onErrorDag(Dag, IndentLevel, O);
+    }
+    else if (ActionName == "warning") {
+      this->onWarningDag(Dag, IndentLevel, O);
     }
     else if (ActionName == "forward") {
       checkNumberOfArguments(&Dag, 1);
@@ -1554,21 +1800,13 @@ class EmitActionHandler {
     }
   }
  public:
-  EmitActionHandler(const OptionDescriptions& OD)
+  EmitActionHandlersCallback(const OptionDescriptions& OD)
     : OptDescs(OD) {}
 
-  void operator()(const Init* Statement, unsigned IndentLevel,
-                  raw_ostream& O) const
+  void operator()(const Init* Statement,
+                  unsigned IndentLevel, raw_ostream& O) const
   {
-    if (typeid(*Statement) == typeid(ListInit)) {
-      const ListInit& DagList = *static_cast<const ListInit*>(Statement);
-      for (ListInit::const_iterator B = DagList.begin(), E = DagList.end();
-           B != E; ++B)
-        this->processActionDag(*B, IndentLevel, O);
-    }
-    else {
-      this->processActionDag(Statement, IndentLevel, O);
-    }
+    this->processActionDag(Statement, IndentLevel, O);
   }
 };
 
@@ -1593,9 +1831,20 @@ public:
   {}
 
   void operator()(const Init* CmdLine) {
+    // Ignore nested 'case' DAG.
+    if (typeid(*CmdLine) == typeid(DagInit))
+      return;
+
     if (IsOutFileIndexCheckRequiredStr(CmdLine))
       *ret_ = true;
   }
+
+  void operator()(const DagInit* Test, unsigned, bool) {
+    this->operator()(Test);
+  }
+  void operator()(const Init* Statement, unsigned) {
+    this->operator()(Statement);
+  }
 };
 
 bool IsOutFileIndexCheckRequiredCase (Init* CmdLine) {
@@ -1652,7 +1901,7 @@ void EmitGenerateActionMethod (const ToolDescription& D,
 
   // For every understood option, emit handling code.
   if (D.Actions)
-    EmitCaseConstructHandler(D.Actions, Indent2, EmitActionHandler(OptDescs),
+    EmitCaseConstructHandler(D.Actions, Indent2, EmitActionHandlersCallback(OptDescs),
                              false, OptDescs, O);
 
   O << '\n';
@@ -1870,10 +2119,93 @@ void EmitOptionDefinitions (const OptionDescriptions& descs,
   O << '\n';
 }
 
-/// EmitPopulateLanguageMap - Emit the PopulateLanguageMap() function.
+/// EmitPreprocessOptionsCallback - Helper function passed to
+/// EmitCaseConstructHandler() by EmitPreprocessOptions().
+class EmitPreprocessOptionsCallback : ActionHandlingCallbackBase {
+  const OptionDescriptions& OptDescs_;
+
+  void onUnsetOption(Init* i, unsigned IndentLevel, raw_ostream& O) {
+    const std::string& OptName = InitPtrToString(i);
+    const OptionDescription& OptDesc = OptDescs_.FindOption(OptName);
+
+    if (OptDesc.isSwitch()) {
+      O.indent(IndentLevel) << OptDesc.GenVariableName() << " = false;\n";
+    }
+    else if (OptDesc.isParameter()) {
+      O.indent(IndentLevel) << OptDesc.GenVariableName() << " = \"\";\n";
+    }
+    else if (OptDesc.isList()) {
+      O.indent(IndentLevel) << OptDesc.GenVariableName() << ".clear();\n";
+    }
+    else {
+      throw "Can't apply 'unset_option' to alias option '" + OptName + "'";
+    }
+  }
+
+  void processDag(const Init* I, unsigned IndentLevel, raw_ostream& O)
+  {
+    const DagInit& d = InitPtrToDag(I);
+    const std::string& OpName = GetOperatorName(d);
+
+    if (OpName == "warning") {
+      this->onWarningDag(d, IndentLevel, O);
+    }
+    else if (OpName == "error") {
+      this->onWarningDag(d, IndentLevel, O);
+    }
+    else if (OpName == "unset_option") {
+      checkNumberOfArguments(&d, 1);
+      Init* I = d.getArg(0);
+      if (typeid(*I) == typeid(ListInit)) {
+        const ListInit& DagList = *static_cast<const ListInit*>(I);
+        for (ListInit::const_iterator B = DagList.begin(), E = DagList.end();
+             B != E; ++B)
+          this->onUnsetOption(*B, IndentLevel, O);
+      }
+      else {
+        this->onUnsetOption(I, IndentLevel, O);
+      }
+    }
+    else {
+      throw "Unknown operator in the option preprocessor: '" + OpName + "'!"
+        "\nOnly 'warning', 'error' and 'unset_option' are allowed.";
+    }
+  }
+
+public:
+
+  void operator()(const Init* I, unsigned IndentLevel, raw_ostream& O) {
+      this->processDag(I, IndentLevel, O);
+  }
+
+  EmitPreprocessOptionsCallback(const OptionDescriptions& OptDescs)
+  : OptDescs_(OptDescs)
+  {}
+};
+
+/// EmitPreprocessOptions - Emit the PreprocessOptionsLocal() function.
+void EmitPreprocessOptions (const RecordKeeper& Records,
+                            const OptionDescriptions& OptDecs, raw_ostream& O)
+{
+  O << "void PreprocessOptionsLocal() {\n";
+
+  const RecordVector& OptionPreprocessors =
+    Records.getAllDerivedDefinitions("OptionPreprocessor");
+
+  for (RecordVector::const_iterator B = OptionPreprocessors.begin(),
+         E = OptionPreprocessors.end(); B!=E; ++B) {
+    DagInit* Case = (*B)->getValueAsDag("preprocessor");
+    EmitCaseConstructHandler(Case, Indent1,
+                             EmitPreprocessOptionsCallback(OptDecs),
+                             false, OptDecs, O);
+  }
+
+  O << "}\n\n";
+}
+
+/// EmitPopulateLanguageMap - Emit the PopulateLanguageMapLocal() function.
 void EmitPopulateLanguageMap (const RecordKeeper& Records, raw_ostream& O)
 {
-  // Generate code
   O << "void PopulateLanguageMapLocal(LanguageMap& langMap) {\n";
 
   // Get the relevant field out of RecordKeeper
@@ -1907,7 +2239,7 @@ void EmitPopulateLanguageMap (const RecordKeeper& Records, raw_ostream& O)
 void IncDecWeight (const Init* i, unsigned IndentLevel,
                    raw_ostream& O) {
   const DagInit& d = InitPtrToDag(i);
-  const std::string& OpName = d.getOperator()->getAsString();
+  const std::string& OpName = GetOperatorName(d);
 
   if (OpName == "inc_weight") {
     O.indent(IndentLevel) << "ret += ";
@@ -1916,17 +2248,16 @@ void IncDecWeight (const Init* i, unsigned IndentLevel,
     O.indent(IndentLevel) << "ret -= ";
   }
   else if (OpName == "error") {
-    O.indent(IndentLevel)
-      << "throw std::runtime_error(\"" <<
-      (d.getNumArgs() >= 1 ? InitPtrToString(d.getArg(0))
-       : "Unknown error!")
-      << "\");\n";
+    checkNumberOfArguments(&d, 1);
+    O.indent(IndentLevel) << "throw std::runtime_error(\""
+                          << InitPtrToString(d.getArg(0))
+                          << "\");\n";
     return;
   }
-
-  else
-    throw "Unknown operator in edge properties list: " + OpName + '!' +
+  else {
+    throw "Unknown operator in edge properties list: '" + OpName + "'!"
       "\nOnly 'inc_weight', 'dec_weight' and 'error' are allowed.";
+  }
 
   if (d.getNumArgs() > 0)
     O << InitPtrToInt(d.getArg(0)) << ";\n";
@@ -1975,7 +2306,7 @@ void EmitEdgeClasses (const RecordVector& EdgeVector,
   }
 }
 
-/// EmitPopulateCompilationGraph - Emit the PopulateCompilationGraph()
+/// EmitPopulateCompilationGraph - Emit the PopulateCompilationGraphLocal()
 /// function.
 void EmitPopulateCompilationGraph (const RecordVector& EdgeVector,
                                    const ToolDescriptions& ToolDescs,
@@ -2024,6 +2355,11 @@ public:
 
   void operator()(const Init* CmdLine) {
     StrVector cmds;
+
+    // Ignore nested 'case' DAG.
+    if (typeid(*CmdLine) == typeid(DagInit))
+      return;
+
     TokenizeCmdline(InitPtrToString(CmdLine), cmds);
     for (StrVector::const_iterator B = cmds.begin(), E = cmds.end();
          B != E; ++B) {
@@ -2053,6 +2389,13 @@ public:
       }
     }
   }
+
+  void operator()(const DagInit* Test, unsigned, bool) {
+    this->operator()(Test);
+  }
+  void operator()(const Init* Statement, unsigned) {
+    this->operator()(Statement);
+  }
 };
 
 /// FillInHookNames - Actually extract the hook names from all command
@@ -2104,6 +2447,8 @@ void EmitRegisterPlugin(int Priority, raw_ostream& O) {
   O << "struct Plugin : public llvmc::BasePlugin {\n\n";
   O.indent(Indent1) << "int Priority() const { return "
                     << Priority << "; }\n\n";
+  O.indent(Indent1) << "void PreprocessOptions() const\n";
+  O.indent(Indent1) << "{ PreprocessOptionsLocal(); }\n\n";
   O.indent(Indent1) << "void PopulateLanguageMap(LanguageMap& langMap) const\n";
   O.indent(Indent1) << "{ PopulateLanguageMapLocal(langMap); }\n\n";
   O.indent(Indent1)
@@ -2123,7 +2468,8 @@ void EmitIncludes(raw_ostream& O) {
     << "#include \"llvm/CompilerDriver/Tool.h\"\n\n"
 
     << "#include \"llvm/ADT/StringExtras.h\"\n"
-    << "#include \"llvm/Support/CommandLine.h\"\n\n"
+    << "#include \"llvm/Support/CommandLine.h\"\n"
+    << "#include \"llvm/Support/raw_ostream.h\"\n\n"
 
     << "#include <cstdlib>\n"
     << "#include <stdexcept>\n\n"
@@ -2223,8 +2569,11 @@ void EmitPluginCode(const PluginData& Data, raw_ostream& O) {
 
   O << "namespace {\n\n";
 
-  // Emit PopulateLanguageMap() function
-  // (a language map maps from file extensions to language names).
+  // Emit PreprocessOptionsLocal() function.
+  EmitPreprocessOptions(Records, Data.OptDescs, O);
+
+  // Emit PopulateLanguageMapLocal() function
+  // (language map maps from file extensions to language names).
   EmitPopulateLanguageMap(Records, O);
 
   // Emit Tool classes.
@@ -2235,7 +2584,7 @@ void EmitPluginCode(const PluginData& Data, raw_ostream& O) {
   // Emit Edge# classes.
   EmitEdgeClasses(Data.Edges, Data.OptDescs, O);
 
-  // Emit PopulateCompilationGraph() function.
+  // Emit PopulateCompilationGraphLocal() function.
   EmitPopulateCompilationGraph(Data.Edges, Data.ToolDescs, O);
 
   // Emit code for plugin registration.
diff --git a/utils/TableGen/LLVMCConfigurationEmitter.h b/utils/TableGen/LLVMCConfigurationEmitter.h
index 347f6f1..b37b83f 100644
--- a/utils/TableGen/LLVMCConfigurationEmitter.h
+++ b/utils/TableGen/LLVMCConfigurationEmitter.h
@@ -21,9 +21,8 @@ namespace llvm {
   /// LLVMCConfigurationEmitter - TableGen backend that generates
   /// configuration code for LLVMC.
   class LLVMCConfigurationEmitter : public TableGenBackend {
-    RecordKeeper &Records;
   public:
-    explicit LLVMCConfigurationEmitter(RecordKeeper &R) : Records(R) {}
+    explicit LLVMCConfigurationEmitter(RecordKeeper&) {}
 
     // run - Output the asmwriter, returning true on failure.
     void run(raw_ostream &o);
diff --git a/utils/TableGen/StringToOffsetTable.h b/utils/TableGen/StringToOffsetTable.h
index d9d7cf4..ac9422c 100644
--- a/utils/TableGen/StringToOffsetTable.h
+++ b/utils/TableGen/StringToOffsetTable.h
@@ -10,9 +10,10 @@
 #ifndef TBLGEN_STRING_TO_OFFSET_TABLE_H
 #define TBLGEN_STRING_TO_OFFSET_TABLE_H
 
+#include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/StringMap.h"
-#include "llvm/Support/raw_ostream.h"
 #include "llvm/ADT/StringExtras.h"
+#include "llvm/Support/raw_ostream.h"
 
 namespace llvm {
 
@@ -38,9 +39,13 @@ public:
   }
   
   void EmitString(raw_ostream &O) {
+    // Escape the string.
+    SmallString<256> Str;
+    raw_svector_ostream(Str).write_escaped(AggregateString);
+    AggregateString = Str.str();
+
     O << "    \"";
     unsigned CharsPrinted = 0;
-    EscapeString(AggregateString);
     for (unsigned i = 0, e = AggregateString.size(); i != e; ++i) {
       if (CharsPrinted > 70) {
         O << "\"\n    \"";