Convert assert(0) to llvm_unreachable

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149967 91177308-0d34-0410-b5e6-96231b3b80d8

30 files changed, 66 insertions, 89 deletions

diff --git a/lib/Analysis/ConstantFolding.cpp b/lib/Analysis/ConstantFolding.cpp
index 6e2a8d4756..7a0a4e1e82 100644
--- a/lib/Analysis/ConstantFolding.cpp
+++ b/lib/Analysis/ConstantFolding.cpp
@@ -862,7 +862,7 @@ Constant *llvm::ConstantFoldInstOperands(unsigned Opcode, Type *DestTy,
   switch (Opcode) {
   default: return 0;
   case Instruction::ICmp:
-  case Instruction::FCmp: assert(0 && "Invalid for compares");
+  case Instruction::FCmp: llvm_unreachable("Invalid for compares");
   case Instruction::Call:
     if (Function *F = dyn_cast<Function>(Ops.back()))
       if (canConstantFoldCallTo(F))
@@ -1390,7 +1390,7 @@ llvm::ConstantFoldCall(Function *F, ArrayRef<Constant *> Operands,
           APInt Res;
           bool Overflow;
           switch (F->getIntrinsicID()) {
-          default: assert(0 && "Invalid case");
+          default: llvm_unreachable("Invalid case");
           case Intrinsic::sadd_with_overflow:
             Res = Op1->getValue().sadd_ov(Op2->getValue(), Overflow);
             break;
diff --git a/lib/Analysis/DebugInfo.cpp b/lib/Analysis/DebugInfo.cpp
index 5cbd15e4c7..405ed31d32 100644
--- a/lib/Analysis/DebugInfo.cpp
+++ b/lib/Analysis/DebugInfo.cpp
@@ -583,8 +583,7 @@ StringRef DIScope::getFilename() const {
     return DIType(DbgNode).getFilename();
   if (isFile())
     return DIFile(DbgNode).getFilename();
-  assert(0 && "Invalid DIScope!");
-  return StringRef();
+  llvm_unreachable("Invalid DIScope!");
 }
 
 StringRef DIScope::getDirectory() const {
@@ -604,8 +603,7 @@ StringRef DIScope::getDirectory() const {
     return DIType(DbgNode).getDirectory();
   if (isFile())
     return DIFile(DbgNode).getDirectory();
-  assert(0 && "Invalid DIScope!");
-  return StringRef();
+  llvm_unreachable("Invalid DIScope!");
 }
 
 DIArray DICompileUnit::getEnumTypes() const {
diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp
index 6605586654..bce7e79318 100644
--- a/lib/Analysis/InstructionSimplify.cpp
+++ b/lib/Analysis/InstructionSimplify.cpp
@@ -1595,8 +1595,7 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
   if (match(RHS, m_Zero())) {
     bool LHSKnownNonNegative, LHSKnownNegative;
     switch (Pred) {
-    default:
-      assert(false && "Unknown ICmp predicate!");
+    default: llvm_unreachable("Unknown ICmp predicate!");
     case ICmpInst::ICMP_ULT:
       return getFalse(ITy);
     case ICmpInst::ICMP_UGE:
@@ -1766,8 +1765,7 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
         // there.  Use this to work out the result of the comparison.
         if (RExt != CI) {
           switch (Pred) {
-          default:
-            assert(false && "Unknown ICmp predicate!");
+          default: llvm_unreachable("Unknown ICmp predicate!");
           // LHS <u RHS.
           case ICmpInst::ICMP_EQ:
           case ICmpInst::ICMP_UGT:
@@ -1826,8 +1824,7 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
         // bits there.  Use this to work out the result of the comparison.
         if (RExt != CI) {
           switch (Pred) {
-          default:
-            assert(false && "Unknown ICmp predicate!");
+          default: llvm_unreachable("Unknown ICmp predicate!");
           case ICmpInst::ICMP_EQ:
             return ConstantInt::getFalse(CI->getContext());
           case ICmpInst::ICMP_NE:
diff --git a/lib/AsmParser/LLParser.cpp b/lib/AsmParser/LLParser.cpp
index 81bad631cf..068be3d47c 100644
--- a/lib/AsmParser/LLParser.cpp
+++ b/lib/AsmParser/LLParser.cpp
@@ -2837,7 +2837,7 @@ bool LLParser::ParseBasicBlock(PerFunctionState &PFS) {
     }
 
     switch (ParseInstruction(Inst, BB, PFS)) {
-    default: assert(0 && "Unknown ParseInstruction result!");
+    default: llvm_unreachable("Unknown ParseInstruction result!");
     case InstError: return true;
     case InstNormal:
       BB->getInstList().push_back(Inst);
diff --git a/lib/ExecutionEngine/ExecutionEngine.cpp b/lib/ExecutionEngine/ExecutionEngine.cpp
index b9356dcd0a..2890174bc9 100644
--- a/lib/ExecutionEngine/ExecutionEngine.cpp
+++ b/lib/ExecutionEngine/ExecutionEngine.cpp
@@ -1149,6 +1149,6 @@ void ExecutionEngineState::AddressMapConfig::onDelete(ExecutionEngineState *EES,
 void ExecutionEngineState::AddressMapConfig::onRAUW(ExecutionEngineState *,
                                                     const GlobalValue *,
                                                     const GlobalValue *) {
-  assert(false && "The ExecutionEngine doesn't know how to handle a"
-         " RAUW on a value it has a global mapping for.");
+  llvm_unreachable("The ExecutionEngine doesn't know how to handle a"
+                   " RAUW on a value it has a global mapping for.");
 }
diff --git a/lib/ExecutionEngine/JIT/JIT.cpp b/lib/ExecutionEngine/JIT/JIT.cpp
index eb2e19d392..f715f6f3a2 100644
--- a/lib/ExecutionEngine/JIT/JIT.cpp
+++ b/lib/ExecutionEngine/JIT/JIT.cpp
@@ -706,9 +706,8 @@ void *JIT::getPointerToBasicBlock(BasicBlock *BB) {
   if (I != getBasicBlockAddressMap(locked).end()) {
     return I->second;
   } else {
-    assert(0 && "JIT does not have BB address for address-of-label, was"
-           " it eliminated by optimizer?");
-    return 0;
+    llvm_unreachable("JIT does not have BB address for address-of-label, was"
+                     " it eliminated by optimizer?");
   }
 }
 
diff --git a/lib/ExecutionEngine/JIT/JITEmitter.cpp b/lib/ExecutionEngine/JIT/JITEmitter.cpp
index 26201c397d..504c8bdffd 100644
--- a/lib/ExecutionEngine/JIT/JITEmitter.cpp
+++ b/lib/ExecutionEngine/JIT/JITEmitter.cpp
@@ -76,8 +76,8 @@ namespace {
   struct NoRAUWValueMapConfig : public ValueMapConfig<ValueTy> {
     typedef JITResolverState *ExtraData;
     static void onRAUW(JITResolverState *, Value *Old, Value *New) {
-      assert(false && "The JIT doesn't know how to handle a"
-             " RAUW on a value it has emitted.");
+      llvm_unreachable("The JIT doesn't know how to handle a"
+                       " RAUW on a value it has emitted.");
     }
   };
 
@@ -1162,7 +1162,7 @@ void JITEmitter::emitJumpTableInfo(MachineJumpTableInfo *MJTI) {
     break;
   }
   case MachineJumpTableInfo::EK_GPRel64BlockAddress:
-    assert(false &&
+    llvm_unreachable(
            "JT Info emission not implemented for GPRel64BlockAddress yet.");
   }
 }
diff --git a/lib/ExecutionEngine/MCJIT/MCJIT.cpp b/lib/ExecutionEngine/MCJIT/MCJIT.cpp
index 6982e74562..5f93a8d3ca 100644
--- a/lib/ExecutionEngine/MCJIT/MCJIT.cpp
+++ b/lib/ExecutionEngine/MCJIT/MCJIT.cpp
@@ -213,6 +213,5 @@ GenericValue MCJIT::runFunction(Function *F,
     }
   }
 
-  assert(0 && "Full-featured argument passing not supported yet!");
-  return GenericValue();
+  llvm_unreachable("Full-featured argument passing not supported yet!");
 }
diff --git a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
index c0845fbbb2..e15b200c5e 100644
--- a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
+++ b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
@@ -185,9 +185,7 @@ void RuntimeDyldELF::resolveX86_64Relocation(StringRef Name,
   }
 
   switch (RE.Type) {
-  default:
-    assert(0 && ("Relocation type not implemented yet!"));
-  break;
+  default: llvm_unreachable("Relocation type not implemented yet!");
   case ELF::R_X86_64_64: {
     uint8_t **Target = reinterpret_cast<uint8_t**>(TargetAddr);
     *Target = Addr + RE.Addend;
@@ -249,8 +247,7 @@ void RuntimeDyldELF::resolveX86Relocation(StringRef Name,
     default:
       // There are other relocation types, but it appears these are the
       //  only ones currently used by the LLVM ELF object writer
-      assert(0 && ("Relocation type not implemented yet!"));
-      break;
+      llvm_unreachable("Relocation type not implemented yet!");
   }
 }
 
@@ -272,9 +269,7 @@ void RuntimeDyldELF::resolveRelocation(StringRef Name,
   case Triple::arm:
     resolveArmRelocation(Name, Addr, RE);
     break;
-  default:
-    assert(0 && "Unsupported CPU type!");
-    break;
+  default: llvm_unreachable("Unsupported CPU type!");
   }
 }
 
diff --git a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
index 669ff4c6f8..4be91d347b 100644
--- a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
+++ b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
@@ -26,7 +26,7 @@ resolveRelocation(uint8_t *Address, uint64_t Value, bool isPCRel,
                   unsigned Type, unsigned Size, int64_t Addend) {
   // This just dispatches to the proper target specific routine.
   switch (CPUType) {
-  default: assert(0 && "Unsupported CPU type!");
+  default: llvm_unreachable("Unsupported CPU type!");
   case mach::CTM_x86_64:
     return resolveX86_64Relocation((uintptr_t)Address, (uintptr_t)Value,
                                    isPCRel, Type, Size, Addend);
diff --git a/lib/Linker/LinkModules.cpp b/lib/Linker/LinkModules.cpp
index 60fa9a76e2..73ae6ad8c2 100644
--- a/lib/Linker/LinkModules.cpp
+++ b/lib/Linker/LinkModules.cpp
@@ -267,7 +267,7 @@ Type *TypeMapTy::getImpl(Type *Ty) {
     
     // Otherwise, rebuild a modified type.
     switch (Ty->getTypeID()) {
-    default: assert(0 && "unknown derived type to remap");
+    default: llvm_unreachable("unknown derived type to remap");
     case Type::ArrayTyID:
       return *Entry = ArrayType::get(ElementTypes[0],
                                      cast<ArrayType>(Ty)->getNumElements());
diff --git a/lib/MC/MCAsmStreamer.cpp b/lib/MC/MCAsmStreamer.cpp
index ba6dee7cc2..f7c6765ff3 100644
--- a/lib/MC/MCAsmStreamer.cpp
+++ b/lib/MC/MCAsmStreamer.cpp
@@ -394,7 +394,7 @@ void MCAsmStreamer::EmitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel,
 void MCAsmStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
                                         MCSymbolAttr Attribute) {
   switch (Attribute) {
-  case MCSA_Invalid: assert(0 && "Invalid symbol attribute");
+  case MCSA_Invalid: llvm_unreachable("Invalid symbol attribute");
   case MCSA_ELF_TypeFunction:    /// .type _foo, STT_FUNC  # aka @function
   case MCSA_ELF_TypeIndFunction: /// .type _foo, STT_GNU_IFUNC
   case MCSA_ELF_TypeObject:      /// .type _foo, STT_OBJECT  # aka @object
@@ -406,7 +406,7 @@ void MCAsmStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
     OS << "\t.type\t" << *Symbol << ','
        << ((MAI.getCommentString()[0] != '@') ? '@' : '%');
     switch (Attribute) {
-    default: assert(0 && "Unknown ELF .type");
+    default: llvm_unreachable("Unknown ELF .type");
     case MCSA_ELF_TypeFunction:    OS << "function"; break;
     case MCSA_ELF_TypeIndFunction: OS << "gnu_indirect_function"; break;
     case MCSA_ELF_TypeObject:      OS << "object"; break;
diff --git a/lib/MC/MCAssembler.cpp b/lib/MC/MCAssembler.cpp
index 0087f67b43..c041f65640 100644
--- a/lib/MC/MCAssembler.cpp
+++ b/lib/MC/MCAssembler.cpp
@@ -348,8 +348,7 @@ uint64_t MCAssembler::computeFragmentSize(const MCAsmLayout &Layout,
     return cast<MCDwarfCallFrameFragment>(F).getContents().size();
   }
 
-  assert(0 && "invalid fragment kind");
-  return 0;
+  llvm_unreachable("invalid fragment kind");
 }
 
 void MCAsmLayout::LayoutFragment(MCFragment *F) {
@@ -414,8 +413,7 @@ static void WriteFragmentData(const MCAssembler &Asm, const MCAsmLayout &Layout,
     // Otherwise, write out in multiples of the value size.
     for (uint64_t i = 0; i != Count; ++i) {
       switch (AF.getValueSize()) {
-      default:
-        assert(0 && "Invalid size!");
+      default: llvm_unreachable("Invalid size!");
       case 1: OW->Write8 (uint8_t (AF.getValue())); break;
       case 2: OW->Write16(uint16_t(AF.getValue())); break;
       case 4: OW->Write32(uint32_t(AF.getValue())); break;
@@ -439,8 +437,7 @@ static void WriteFragmentData(const MCAssembler &Asm, const MCAsmLayout &Layout,
 
     for (uint64_t i = 0, e = FF.getSize() / FF.getValueSize(); i != e; ++i) {
       switch (FF.getValueSize()) {
-      default:
-        assert(0 && "Invalid size!");
+      default: llvm_unreachable("Invalid size!");
       case 1: OW->Write8 (uint8_t (FF.getValue())); break;
       case 2: OW->Write16(uint16_t(FF.getValue())); break;
       case 4: OW->Write32(uint32_t(FF.getValue())); break;
@@ -496,8 +493,7 @@ void MCAssembler::writeSectionData(const MCSectionData *SD,
     for (MCSectionData::const_iterator it = SD->begin(),
            ie = SD->end(); it != ie; ++it) {
       switch (it->getKind()) {
-      default:
-        assert(0 && "Invalid fragment in virtual section!");
+      default: llvm_unreachable("Invalid fragment in virtual section!");
       case MCFragment::FT_Data: {
         // Check that we aren't trying to write a non-zero contents (or fixups)
         // into a virtual section. This is to support clients which use standard
diff --git a/lib/MC/MCDisassembler/EDMain.cpp b/lib/MC/MCDisassembler/EDMain.cpp
index 3fd355b4bc..c658717b02 100644
--- a/lib/MC/MCDisassembler/EDMain.cpp
+++ b/lib/MC/MCDisassembler/EDMain.cpp
@@ -23,7 +23,7 @@ int EDGetDisassembler(EDDisassemblerRef *disassembler,
                       EDAssemblySyntax_t syntax) {
   EDDisassembler::AssemblySyntax Syntax;
   switch (syntax) {
-  default: assert(0 && "Unknown assembly syntax!");
+  default: llvm_unreachable("Unknown assembly syntax!");
   case kEDAssemblySyntaxX86Intel:
     Syntax = EDDisassembler::kEDAssemblySyntaxX86Intel;
     break;
diff --git a/lib/MC/MCDwarf.cpp b/lib/MC/MCDwarf.cpp
index 65f1ad1e17..1b6dbdc3a3 100644
--- a/lib/MC/MCDwarf.cpp
+++ b/lib/MC/MCDwarf.cpp
@@ -765,8 +765,7 @@ static unsigned getSizeForEncoding(MCStreamer &streamer,
   MCContext &context = streamer.getContext();
   unsigned format = symbolEncoding & 0x0f;
   switch (format) {
-  default:
-    assert(0 && "Unknown Encoding");
+  default: llvm_unreachable("Unknown Encoding");
   case dwarf::DW_EH_PE_absptr:
   case dwarf::DW_EH_PE_signed:
     return context.getAsmInfo().getPointerSize();
diff --git a/lib/MC/MCELFStreamer.cpp b/lib/MC/MCELFStreamer.cpp
index 42a7ebf7d4..607e01cd82 100644
--- a/lib/MC/MCELFStreamer.cpp
+++ b/lib/MC/MCELFStreamer.cpp
@@ -60,24 +60,24 @@ public:
   virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol);
   virtual void EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute);
   virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
-    assert(0 && "ELF doesn't support this directive");
+    llvm_unreachable("ELF doesn't support this directive");
   }
   virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
                                 unsigned ByteAlignment);
   virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol) {
-    assert(0 && "ELF doesn't support this directive");
+    llvm_unreachable("ELF doesn't support this directive");
   }
 
   virtual void EmitCOFFSymbolStorageClass(int StorageClass) {
-    assert(0 && "ELF doesn't support this directive");
+    llvm_unreachable("ELF doesn't support this directive");
   }
 
   virtual void EmitCOFFSymbolType(int Type) {
-    assert(0 && "ELF doesn't support this directive");
+    llvm_unreachable("ELF doesn't support this directive");
   }
 
   virtual void EndCOFFSymbolDef() {
-    assert(0 && "ELF doesn't support this directive");
+    llvm_unreachable("ELF doesn't support this directive");
   }
 
   virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
@@ -90,11 +90,11 @@ public:
 
   virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
                             unsigned Size = 0, unsigned ByteAlignment = 0) {
-    assert(0 && "ELF doesn't support this directive");
+    llvm_unreachable("ELF doesn't support this directive");
   }
   virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
                               uint64_t Size, unsigned ByteAlignment = 0) {
-    assert(0 && "ELF doesn't support this directive");
+    llvm_unreachable("ELF doesn't support this directive");
   }
   virtual void EmitBytes(StringRef Data, unsigned AddrSpace);
   virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
@@ -180,7 +180,7 @@ void MCELFStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
     return;
   }
 
-  assert(0 && "invalid assembler flag!");
+  llvm_unreachable("invalid assembler flag!");
 }
 
 void MCELFStreamer::EmitThumbFunc(MCSymbol *Func) {
@@ -250,8 +250,7 @@ void MCELFStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
   case MCSA_WeakDefAutoPrivate:
   case MCSA_Invalid:
   case MCSA_IndirectSymbol:
-    assert(0 && "Invalid symbol attribute for ELF!");
-    break;
+    llvm_unreachable("Invalid symbol attribute for ELF!");
 
   case MCSA_ELF_TypeGnuUniqueObject:
     // Ignore for now.
diff --git a/lib/MC/MCExpr.cpp b/lib/MC/MCExpr.cpp
index 9a19f6deba..ccdccdf514 100644
--- a/lib/MC/MCExpr.cpp
+++ b/lib/MC/MCExpr.cpp
@@ -132,7 +132,7 @@ void MCExpr::print(raw_ostream &OS) const {
   }
   }
 
-  assert(0 && "Invalid expression kind!");
+  llvm_unreachable("Invalid expression kind!");
 }
 
 void MCExpr::dump() const {
@@ -576,8 +576,7 @@ bool MCExpr::EvaluateAsRelocatableImpl(MCValue &Res,
   }
   }
 
-  assert(0 && "Invalid assembly expression kind!");
-  return false;
+  llvm_unreachable("Invalid assembly expression kind!");
 }
 
 const MCSection *MCExpr::FindAssociatedSection() const {
@@ -618,6 +617,5 @@ const MCSection *MCExpr::FindAssociatedSection() const {
   }
   }
 
-  assert(0 && "Invalid assembly expression kind!");
-  return 0;
+  llvm_unreachable("Invalid assembly expression kind!");
 }
diff --git a/lib/MC/MCInstPrinter.cpp b/lib/MC/MCInstPrinter.cpp
index 2317a2891f..3060ad6003 100644
--- a/lib/MC/MCInstPrinter.cpp
+++ b/lib/MC/MCInstPrinter.cpp
@@ -10,6 +10,7 @@
 #include "llvm/MC/MCInstPrinter.h"
 #include "llvm/MC/MCAsmInfo.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/raw_ostream.h"
 using namespace llvm;
 
@@ -23,7 +24,7 @@ StringRef MCInstPrinter::getOpcodeName(unsigned Opcode) const {
 }
 
 void MCInstPrinter::printRegName(raw_ostream &OS, unsigned RegNo) const {
-  assert(0 && "Target should implement this");
+  llvm_unreachable("Target should implement this");
 }
 
 void MCInstPrinter::printAnnotation(raw_ostream &OS, StringRef Annot) {
diff --git a/lib/MC/MCMachOStreamer.cpp b/lib/MC/MCMachOStreamer.cpp
index bf659762fb..bc6cf77321 100644
--- a/lib/MC/MCMachOStreamer.cpp
+++ b/lib/MC/MCMachOStreamer.cpp
@@ -53,23 +53,23 @@ public:
   virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
                                 unsigned ByteAlignment);
   virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol) {
-    assert(0 && "macho doesn't support this directive");
+    llvm_unreachable("macho doesn't support this directive");
   }
   virtual void EmitCOFFSymbolStorageClass(int StorageClass) {
-    assert(0 && "macho doesn't support this directive");
+    llvm_unreachable("macho doesn't support this directive");
   }
   virtual void EmitCOFFSymbolType(int Type) {
-    assert(0 && "macho doesn't support this directive");
+    llvm_unreachable("macho doesn't support this directive");
   }
   virtual void EndCOFFSymbolDef() {
-    assert(0 && "macho doesn't support this directive");
+    llvm_unreachable("macho doesn't support this directive");
   }
   virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
-    assert(0 && "macho doesn't support this directive");
+    llvm_unreachable("macho doesn't support this directive");
   }
   virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
                                      unsigned ByteAlignment) {
-    assert(0 && "macho doesn't support this directive");
+    llvm_unreachable("macho doesn't support this directive");
   }
   virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
                             unsigned Size = 0, unsigned ByteAlignment = 0);
@@ -211,8 +211,7 @@ void MCMachOStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
   case MCSA_Protected:
   case MCSA_Weak:
   case MCSA_Local:
-    assert(0 && "Invalid symbol attribute for Mach-O!");
-    break;
+    llvm_unreachable("Invalid symbol attribute for Mach-O!");
 
   case MCSA_Global:
     SD.setExternal(true);
diff --git a/lib/MC/MCParser/AsmParser.cpp b/lib/MC/MCParser/AsmParser.cpp
index dad72d2050..bd5956f9b4 100644
--- a/lib/MC/MCParser/AsmParser.cpp
+++ b/lib/MC/MCParser/AsmParser.cpp
@@ -805,8 +805,7 @@ AsmParser::ApplyModifierToExpr(const MCExpr *E,
   }
   }
 
-  assert(0 && "Invalid expression kind!");
-  return 0;
+  llvm_unreachable("Invalid expression kind!");
 }
 
 /// ParseExpression - Parse an expression and return it.
diff --git a/lib/MC/MCStreamer.cpp b/lib/MC/MCStreamer.cpp
index 50a5f8d169..6d53fb196c 100644
--- a/lib/MC/MCStreamer.cpp
+++ b/lib/MC/MCStreamer.cpp
@@ -600,7 +600,7 @@ void MCStreamer::EmitWin64EHEndProlog() {
 }
 
 void MCStreamer::EmitCOFFSecRel32(MCSymbol const *Symbol) {
-  assert(0 && "This file format doesn't support this directive");
+  llvm_unreachable("This file format doesn't support this directive");
 }
 
 void MCStreamer::EmitFnStart() {
diff --git a/lib/Support/ConstantRange.cpp b/lib/Support/ConstantRange.cpp
index 0432921b87..5206cf1f9b 100644
--- a/lib/Support/ConstantRange.cpp
+++ b/lib/Support/ConstantRange.cpp
@@ -55,7 +55,7 @@ ConstantRange ConstantRange::makeICmpRegion(unsigned Pred,
 
   uint32_t W = CR.getBitWidth();
   switch (Pred) {
-    default: assert(0 && "Invalid ICmp predicate to makeICmpRegion()");
+    default: llvm_unreachable("Invalid ICmp predicate to makeICmpRegion()");
     case CmpInst::ICMP_EQ:
       return CR;
     case CmpInst::ICMP_NE:
diff --git a/lib/Support/Triple.cpp b/lib/Support/Triple.cpp
index 7c4da12bfe..f400c9969f 100644
--- a/lib/Support/Triple.cpp
+++ b/lib/Support/Triple.cpp
@@ -459,8 +459,7 @@ std::string Triple::normalize(StringRef Str) {
       bool Valid = false;
       StringRef Comp = Components[Idx];
       switch (Pos) {
-      default:
-        assert(false && "unexpected component type!");
+      default: llvm_unreachable("unexpected component type!");
       case 0:
         Arch = ParseArch(Comp);
         Valid = Arch != UnknownArch;
@@ -618,7 +617,7 @@ bool Triple::getMacOSXVersion(unsigned &Major, unsigned &Minor,
   getOSVersion(Major, Minor, Micro);
 
   switch (getOS()) {
-  default: assert(0 && "unexpected OS for Darwin triple");
+  default: llvm_unreachable("unexpected OS for Darwin triple");
   case Darwin:
     // Default to darwin8, i.e., MacOSX 10.4.
     if (Major == 0)
diff --git a/lib/TableGen/Record.cpp b/lib/TableGen/Record.cpp
index e8f23e4888..fece0df412 100644
--- a/lib/TableGen/Record.cpp
+++ b/lib/TableGen/Record.cpp
@@ -942,7 +942,7 @@ Init *BinOpInit::Fold(Record *CurRec, MultiClass *CurMultiClass) const {
       int64_t LHSv = LHSi->getValue(), RHSv = RHSi->getValue();
       int64_t Result;
       switch (getOpcode()) {
-      default: assert(0 && "Bad opcode!");
+      default: llvm_unreachable("Bad opcode!");
       case SHL: Result = LHSv << RHSv; break;
       case SRA: Result = LHSv >> RHSv; break;
       case SRL: Result = (uint64_t)LHSv >> (uint64_t)RHSv; break;
diff --git a/lib/TableGen/TGParser.cpp b/lib/TableGen/TGParser.cpp
index 0f64f4bcda..c7cf097aee 100644
--- a/lib/TableGen/TGParser.cpp
+++ b/lib/TableGen/TGParser.cpp
@@ -729,7 +729,7 @@ Init *TGParser::ParseOperation(Record *CurRec) {
     RecTy *Type = 0;
 
     switch (Lex.getCode()) {
-    default: assert(0 && "Unhandled code!");
+    default: llvm_unreachable("Unhandled code!");
     case tgtok::XCast:
       Lex.Lex();  // eat the operation
       Code = UnOpInit::CAST;
@@ -845,7 +845,7 @@ Init *TGParser::ParseOperation(Record *CurRec) {
     RecTy *Type = 0;
 
     switch (OpTok) {
-    default: assert(0 && "Unhandled code!");
+    default: llvm_unreachable("Unhandled code!");
     case tgtok::XConcat: Code = BinOpInit::CONCAT;Type = DagRecTy::get(); break;
     case tgtok::XSRA:    Code = BinOpInit::SRA;   Type = IntRecTy::get(); break;
     case tgtok::XSRL:    Code = BinOpInit::SRL;   Type = IntRecTy::get(); break;
@@ -909,7 +909,7 @@ Init *TGParser::ParseOperation(Record *CurRec) {
     tgtok::TokKind LexCode = Lex.getCode();
     Lex.Lex();  // eat the operation
     switch (LexCode) {
-    default: assert(0 && "Unhandled code!");
+    default: llvm_unreachable("Unhandled code!");
     case tgtok::XIf:
       Code = TernOpInit::IF;
       break;
@@ -954,7 +954,7 @@ Init *TGParser::ParseOperation(Record *CurRec) {
     Lex.Lex();  // eat the ')'
 
     switch (LexCode) {
-    default: assert(0 && "Unhandled code!");
+    default: llvm_unreachable("Unhandled code!");
     case tgtok::XIf: {
       // FIXME: The `!if' operator doesn't handle non-TypedInit well at
       // all. This can be made much more robust.
diff --git a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
index d2298a0f7d..7cb56f8fe6 100644
--- a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -110,7 +110,7 @@ static Value *getFCmpValue(bool isordered, unsigned code,
                            InstCombiner::BuilderTy *Builder) {
   CmpInst::Predicate Pred;
   switch (code) {
-  default: assert(0 && "Illegal FCmp code!");
+  default: llvm_unreachable("Illegal FCmp code!");
   case 0: Pred = isordered ? FCmpInst::FCMP_ORD : FCmpInst::FCMP_UNO; break;
   case 1: Pred = isordered ? FCmpInst::FCMP_OGT : FCmpInst::FCMP_UGT; break;
   case 2: Pred = isordered ? FCmpInst::FCMP_OEQ : FCmpInst::FCMP_UEQ; break;
diff --git a/lib/Transforms/InstCombine/InstCombineShifts.cpp b/lib/Transforms/InstCombine/InstCombineShifts.cpp
index a66e650895..b31049e59f 100644
--- a/lib/Transforms/InstCombine/InstCombineShifts.cpp
+++ b/lib/Transforms/InstCombine/InstCombineShifts.cpp
@@ -199,7 +199,7 @@ static Value *GetShiftedValue(Value *V, unsigned NumBits, bool isLeftShift,
   IC.Worklist.Add(I);
 
   switch (I->getOpcode()) {
-  default: assert(0 && "Inconsistency with CanEvaluateShifted");
+  default: llvm_unreachable("Inconsistency with CanEvaluateShifted");
   case Instruction::And:
   case Instruction::Or:
   case Instruction::Xor:
diff --git a/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index b8ead89a8f..150868d577 100644
--- a/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -703,8 +703,7 @@ static uint64_t ValueForPoison(uint64_t PoisonByte, size_t ShadowRedzoneSize) {
   if (ShadowRedzoneSize == 4)
     return (PoisonByte << 24) + (PoisonByte << 16) +
         (PoisonByte << 8) + (PoisonByte);
-  assert(0 && "ShadowRedzoneSize is either 1, 2 or 4");
-  return 0;
+  llvm_unreachable("ShadowRedzoneSize is either 1, 2 or 4");
 }
 
 static void PoisonShadowPartialRightRedzone(uint8_t *Shadow,
diff --git a/lib/Transforms/Scalar/DeadStoreElimination.cpp b/lib/Transforms/Scalar/DeadStoreElimination.cpp
index 8729019705..c8c5360601 100644
--- a/lib/Transforms/Scalar/DeadStoreElimination.cpp
+++ b/lib/Transforms/Scalar/DeadStoreElimination.cpp
@@ -224,7 +224,7 @@ static bool isRemovable(Instruction *I) {
 
   IntrinsicInst *II = cast<IntrinsicInst>(I);
   switch (II->getIntrinsicID()) {
-  default: assert(0 && "doesn't pass 'hasMemoryWrite' predicate");
+  default: llvm_unreachable("doesn't pass 'hasMemoryWrite' predicate");
   case Intrinsic::lifetime_end:
     // Never remove dead lifetime_end's, e.g. because it is followed by a
     // free.
@@ -268,7 +268,7 @@ static Value *getStoredPointerOperand(Instruction *I) {
 
   IntrinsicInst *II = cast<IntrinsicInst>(I);
   switch (II->getIntrinsicID()) {
-  default: assert(false && "Unexpected intrinsic!");
+  default: llvm_unreachable("Unexpected intrinsic!");
   case Intrinsic::init_trampoline:
     return II->getArgOperand(0);
   }
diff --git a/lib/Transforms/Utils/CmpInstAnalysis.cpp b/lib/Transforms/Utils/CmpInstAnalysis.cpp
index 8983e0c4f0..9b099150a7 100644
--- a/lib/Transforms/Utils/CmpInstAnalysis.cpp
+++ b/lib/Transforms/Utils/CmpInstAnalysis.cpp
@@ -72,7 +72,7 @@ unsigned llvm::getICmpCode(const ICmpInst *ICI, bool InvertPred) {
 Value *llvm::getICmpValue(bool Sign, unsigned Code, Value *LHS, Value *RHS,
                           CmpInst::Predicate &NewICmpPred) {
   switch (Code) {
-    default: assert(0 && "Illegal ICmp code!");
+    default: llvm_unreachable("Illegal ICmp code!");
     case 0: // False.
       return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0);
     case 1: NewICmpPred = Sign ? ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT; break;