Fix clang -Wimplicit-fallthrough warnings across llvm, NFC

This patch should not introduce any behavior changes. It consists of
mostly one of two changes:
1. Replacing fall through comments with the LLVM_FALLTHROUGH macro
2. Inserting 'break' before falling through into a case block consisting
   of only 'break'.

We were already using this warning with GCC, but its warning behaves
slightly differently. In this patch, the following differences are
relevant:
1. GCC recognizes comments that say "fall through" as annotations, clang
   doesn't
2. GCC doesn't warn on "case N: foo(); default: break;", clang does
3. GCC doesn't warn when the case contains a switch, but falls through
   the outer case.

I will enable the warning separately in a follow-up patch so that it can
be cleanly reverted if necessary.

Reviewers: alexfh, rsmith, lattner, rtrieu, EricWF, bollu

Differential Revision: https://reviews.llvm.org/D53950

llvm-svn: 345882

61 files changed, 85 insertions, 64 deletions

diff --git a/clang-tools-extra/clang-tidy/google/AvoidCStyleCastsCheck.cpp b/clang-tools-extra/clang-tidy/google/AvoidCStyleCastsCheck.cpp
index bea3ce11591..d6ea7e00429 100644
--- a/clang-tools-extra/clang-tidy/google/AvoidCStyleCastsCheck.cpp
+++ b/clang-tools-extra/clang-tidy/google/AvoidCStyleCastsCheck.cpp
@@ -187,7 +187,7 @@ void AvoidCStyleCastsCheck::check(const MatchFinder::MatchResult &Result) {
       }
       break;
     }
-  // FALLTHROUGH
+    LLVM_FALLTHROUGH;
   case clang::CK_IntegralCast:
     // Convert integral and no-op casts between builtin types and enums to
     // static_cast. A cast from enum to integer may be unnecessary, but it's
diff --git a/clang/lib/ARCMigrate/TransRetainReleaseDealloc.cpp b/clang/lib/ARCMigrate/TransRetainReleaseDealloc.cpp
index f0987786d4e..d199bb93654 100644
--- a/clang/lib/ARCMigrate/TransRetainReleaseDealloc.cpp
+++ b/clang/lib/ARCMigrate/TransRetainReleaseDealloc.cpp
@@ -113,6 +113,7 @@ public:
             return true;
           }
         }
+      break;
     case OMF_dealloc:
       break;
     }
diff --git a/clang/lib/Analysis/CFG.cpp b/clang/lib/Analysis/CFG.cpp
index b998c3f84ed..442aaf35afc 100644
--- a/clang/lib/Analysis/CFG.cpp
+++ b/clang/lib/Analysis/CFG.cpp
@@ -1334,6 +1334,7 @@ void CFGBuilder::findConstructionContexts(
     case CK_NoOp:
     case CK_ConstructorConversion:
       findConstructionContexts(Layer, Cast->getSubExpr());
+      break;
     default:
       break;
     }
diff --git a/clang/lib/Analysis/FormatString.cpp b/clang/lib/Analysis/FormatString.cpp
index d42cf81ac2e..5e2137c7088 100644
--- a/clang/lib/Analysis/FormatString.cpp
+++ b/clang/lib/Analysis/FormatString.cpp
@@ -689,7 +689,7 @@ bool FormatSpecifier::hasValidLengthModifier(const TargetInfo &Target) const {
             break;
         }
       }
-      // Fall through.
+      LLVM_FALLTHROUGH;
     case LengthModifier::AsChar:
     case LengthModifier::AsLongLong:
     case LengthModifier::AsQuad:
diff --git a/clang/lib/Analysis/ReachableCode.cpp b/clang/lib/Analysis/ReachableCode.cpp
index 0d4b78ba027..87f4f7010f9 100644
--- a/clang/lib/Analysis/ReachableCode.cpp
+++ b/clang/lib/Analysis/ReachableCode.cpp
@@ -219,7 +219,7 @@ static bool isConfigurationValue(const Stmt *S,
       return isConfigurationValue(cast<DeclRefExpr>(S)->getDecl(), PP);
     case Stmt::ObjCBoolLiteralExprClass:
       IgnoreYES_NO = true;
-      // Fallthrough.
+      LLVM_FALLTHROUGH;
     case Stmt::CXXBoolLiteralExprClass:
     case Stmt::IntegerLiteralClass: {
       const Expr *E = cast<Expr>(S);
diff --git a/clang/lib/Basic/IdentifierTable.cpp b/clang/lib/Basic/IdentifierTable.cpp
index a5848499064..18580fca6c6 100644
--- a/clang/lib/Basic/IdentifierTable.cpp
+++ b/clang/lib/Basic/IdentifierTable.cpp
@@ -579,6 +579,7 @@ ObjCInstanceTypeFamily Selector::getInstTypeMethodFamily(Selector sel) {
       break;
     case 'i':
       if (startsWithWord(name, "init")) return OIT_Init;
+      break;
     default:
       break;
   }
diff --git a/clang/lib/Basic/Targets/OSTargets.h b/clang/lib/Basic/Targets/OSTargets.h
index 48da6dc950a..0327ff983a7 100644
--- a/clang/lib/Basic/Targets/OSTargets.h
+++ b/clang/lib/Basic/Targets/OSTargets.h
@@ -397,7 +397,7 @@ public:
     case llvm::Triple::x86:
     case llvm::Triple::x86_64:
       this->HasFloat128 = true;
-      // FALLTHROUGH
+      LLVM_FALLTHROUGH;
     default:
       this->MCountName = "__mcount";
       break;
diff --git a/clang/lib/Basic/Targets/X86.h b/clang/lib/Basic/Targets/X86.h
index 07151c7f5b4..05930ae9eec 100644
--- a/clang/lib/Basic/Targets/X86.h
+++ b/clang/lib/Basic/Targets/X86.h
@@ -225,6 +225,7 @@ public:
     case 'Y':
       if ((++I != E) && ((*I == '0') || (*I == 'z')))
         return "xmm0";
+      break;
     default:
       break;
     }
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index bf53e25b2f9..2c7a3d720a7 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -6867,7 +6867,7 @@ Value *CodeGenFunction::EmitAArch64BuiltinExpr(unsigned BuiltinID,
   case NEON::BI__builtin_neon_vcvth_f16_u32:
   case NEON::BI__builtin_neon_vcvth_f16_u64:
     usgn = true;
-    // FALL THROUGH
+    LLVM_FALLTHROUGH;
   case NEON::BI__builtin_neon_vcvth_f16_s16:
   case NEON::BI__builtin_neon_vcvth_f16_s32:
   case NEON::BI__builtin_neon_vcvth_f16_s64: {
@@ -6887,7 +6887,7 @@ Value *CodeGenFunction::EmitAArch64BuiltinExpr(unsigned BuiltinID,
   }
   case NEON::BI__builtin_neon_vcvth_u16_f16:
     usgn = true;
-    // FALL THROUGH
+    LLVM_FALLTHROUGH;
   case NEON::BI__builtin_neon_vcvth_s16_f16: {
     Ops.push_back(EmitScalarExpr(E->getArg(0)));
     Ops[0] = Builder.CreateBitCast(Ops[0], HalfTy);
@@ -6897,7 +6897,7 @@ Value *CodeGenFunction::EmitAArch64BuiltinExpr(unsigned BuiltinID,
   }
   case NEON::BI__builtin_neon_vcvth_u32_f16:
     usgn = true;
-    // FALL THROUGH
+    LLVM_FALLTHROUGH;
   case NEON::BI__builtin_neon_vcvth_s32_f16: {
     Ops.push_back(EmitScalarExpr(E->getArg(0)));
     Ops[0] = Builder.CreateBitCast(Ops[0], HalfTy);
@@ -6907,7 +6907,7 @@ Value *CodeGenFunction::EmitAArch64BuiltinExpr(unsigned BuiltinID,
   }
   case NEON::BI__builtin_neon_vcvth_u64_f16:
     usgn = true;
-    // FALL THROUGH
+    LLVM_FALLTHROUGH;
   case NEON::BI__builtin_neon_vcvth_s64_f16: {
     Ops.push_back(EmitScalarExpr(E->getArg(0)));
     Ops[0] = Builder.CreateBitCast(Ops[0], HalfTy);
diff --git a/clang/lib/CodeGen/CGExprScalar.cpp b/clang/lib/CodeGen/CGExprScalar.cpp
index 0b9a0a45c57..7b024a015cd 100644
--- a/clang/lib/CodeGen/CGExprScalar.cpp
+++ b/clang/lib/CodeGen/CGExprScalar.cpp
@@ -680,7 +680,7 @@ public:
       case LangOptions::SOB_Undefined:
         if (!CGF.SanOpts.has(SanitizerKind::SignedIntegerOverflow))
           return Builder.CreateNSWMul(Ops.LHS, Ops.RHS, "mul");
-        // Fall through.
+        LLVM_FALLTHROUGH;
       case LangOptions::SOB_Trapping:
         if (CanElideOverflowCheck(CGF.getContext(), Ops))
           return Builder.CreateNSWMul(Ops.LHS, Ops.RHS, "mul");
@@ -2305,7 +2305,7 @@ llvm::Value *ScalarExprEmitter::EmitIncDecConsiderOverflowBehavior(
   case LangOptions::SOB_Undefined:
     if (!CGF.SanOpts.has(SanitizerKind::SignedIntegerOverflow))
       return Builder.CreateNSWAdd(InVal, Amount, Name);
-    // Fall through.
+    LLVM_FALLTHROUGH;
   case LangOptions::SOB_Trapping:
     if (!E->canOverflow())
       return Builder.CreateNSWAdd(InVal, Amount, Name);
@@ -3311,7 +3311,7 @@ Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &op) {
     case LangOptions::SOB_Undefined:
       if (!CGF.SanOpts.has(SanitizerKind::SignedIntegerOverflow))
         return Builder.CreateNSWAdd(op.LHS, op.RHS, "add");
-      // Fall through.
+      LLVM_FALLTHROUGH;
     case LangOptions::SOB_Trapping:
       if (CanElideOverflowCheck(CGF.getContext(), op))
         return Builder.CreateNSWAdd(op.LHS, op.RHS, "add");
@@ -3346,7 +3346,7 @@ Value *ScalarExprEmitter::EmitSub(const BinOpInfo &op) {
       case LangOptions::SOB_Undefined:
         if (!CGF.SanOpts.has(SanitizerKind::SignedIntegerOverflow))
           return Builder.CreateNSWSub(op.LHS, op.RHS, "sub");
-        // Fall through.
+        LLVM_FALLTHROUGH;
       case LangOptions::SOB_Trapping:
         if (CanElideOverflowCheck(CGF.getContext(), op))
           return Builder.CreateNSWSub(op.LHS, op.RHS, "sub");
diff --git a/clang/lib/CodeGen/CGObjCRuntime.cpp b/clang/lib/CodeGen/CGObjCRuntime.cpp
index 8390bca7378..4b6f24a03f2 100644
--- a/clang/lib/CodeGen/CGObjCRuntime.cpp
+++ b/clang/lib/CodeGen/CGObjCRuntime.cpp
@@ -296,7 +296,7 @@ void CGObjCRuntime::EmitInitOfCatchParam(CodeGenFunction &CGF,
   switch (paramDecl->getType().getQualifiers().getObjCLifetime()) {
   case Qualifiers::OCL_Strong:
     exn = CGF.EmitARCRetainNonBlock(exn);
-    // fallthrough
+    LLVM_FALLTHROUGH;
 
   case Qualifiers::OCL_None:
   case Qualifiers::OCL_ExplicitNone:
diff --git a/clang/lib/CodeGen/ItaniumCXXABI.cpp b/clang/lib/CodeGen/ItaniumCXXABI.cpp
index b67a64bc89b..e75532142e5 100644
--- a/clang/lib/CodeGen/ItaniumCXXABI.cpp
+++ b/clang/lib/CodeGen/ItaniumCXXABI.cpp
@@ -3088,7 +3088,7 @@ void ItaniumRTTIBuilder::BuildVTablePointer(const Type *Ty) {
     }
 
     assert(isa<ObjCInterfaceType>(Ty));
-    // Fall through.
+    LLVM_FALLTHROUGH;
 
   case Type::ObjCInterface:
     if (cast<ObjCInterfaceType>(Ty)->getDecl()->getSuperClass()) {
@@ -4025,7 +4025,7 @@ static void InitCatchParam(CodeGenFunction &CGF,
       switch (CatchType.getQualifiers().getObjCLifetime()) {
       case Qualifiers::OCL_Strong:
         CastExn = CGF.EmitARCRetainNonBlock(CastExn);
-        // fallthrough
+        LLVM_FALLTHROUGH;
 
       case Qualifiers::OCL_None:
       case Qualifiers::OCL_ExplicitNone:
diff --git a/clang/lib/CodeGen/VarBypassDetector.cpp b/clang/lib/CodeGen/VarBypassDetector.cpp
index 2f8a591a3e7..859cdd4282c 100644
--- a/clang/lib/CodeGen/VarBypassDetector.cpp
+++ b/clang/lib/CodeGen/VarBypassDetector.cpp
@@ -78,7 +78,7 @@ bool VarBypassDetector::BuildScopeInformation(const Stmt *S,
         return false;
       ++StmtsToSkip;
     }
-  // Fall through
+    LLVM_FALLTHROUGH;
 
   case Stmt::GotoStmtClass:
     FromScopes.push_back({S, ParentScope});
diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp
index ea424bb89e8..719474dc765 100644
--- a/clang/lib/Frontend/CompilerInstance.cpp
+++ b/clang/lib/Frontend/CompilerInstance.cpp
@@ -1272,7 +1272,7 @@ static bool compileAndLoadModule(CompilerInstance &ImportingInstance,
           << Module->Name << Locked.getErrorMessage();
       // Clear out any potential leftover.
       Locked.unsafeRemoveLockFile();
-      // FALLTHROUGH
+      LLVM_FALLTHROUGH;
     case llvm::LockFileManager::LFS_Owned:
       // We're responsible for building the module ourselves.
       if (!compileModuleImpl(ImportingInstance, ModuleNameLoc, Module,
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 92a421d2b26..912afba340b 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -1474,7 +1474,7 @@ static InputKind ParseFrontendArgs(FrontendOptions &Opts, ArgList &Args,
       Opts.ProgramAction = frontend::EmitObj; break;
     case OPT_fixit_EQ:
       Opts.FixItSuffix = A->getValue();
-      // fall-through!
+      LLVM_FALLTHROUGH;
     case OPT_fixit:
       Opts.ProgramAction = frontend::FixIt; break;
     case OPT_emit_module:
diff --git a/clang/lib/Frontend/Rewrite/InclusionRewriter.cpp b/clang/lib/Frontend/Rewrite/InclusionRewriter.cpp
index 1631eccd701..2e7baa3d958 100644
--- a/clang/lib/Frontend/Rewrite/InclusionRewriter.cpp
+++ b/clang/lib/Frontend/Rewrite/InclusionRewriter.cpp
@@ -586,6 +586,7 @@ void InclusionRewriter::Process(FileID FileId,
                               LocalEOL, Line, /*EnsureNewline=*/ true);
             WriteLineInfo(FileName, Line, FileType);
             RawLex.SetKeepWhitespaceMode(false);
+            break;
           }
           default:
             break;
diff --git a/clang/lib/Index/CommentToXML.cpp b/clang/lib/Index/CommentToXML.cpp
index 918068a2405..a2659119a2f 100644
--- a/clang/lib/Index/CommentToXML.cpp
+++ b/clang/lib/Index/CommentToXML.cpp
@@ -720,6 +720,7 @@ void CommentASTToXMLConverter::visitBlockCommandComment(
   case CommandTraits::KCI_version:
   case CommandTraits::KCI_warning:
     ParagraphKind = C->getCommandName(Traits);
+    break;
   default:
     break;
   }
diff --git a/clang/lib/Index/USRGeneration.cpp b/clang/lib/Index/USRGeneration.cpp
index f7be0a90b0a..ae1fa1fbc80 100644
--- a/clang/lib/Index/USRGeneration.cpp
+++ b/clang/lib/Index/USRGeneration.cpp
@@ -942,7 +942,7 @@ void USRGenerator::VisitTemplateArgument(const TemplateArgument &Arg) {
 
   case TemplateArgument::TemplateExpansion:
     Out << 'P'; // pack expansion of...
-    // Fall through
+    LLVM_FALLTHROUGH;
   case TemplateArgument::Template:
     VisitTemplateName(Arg.getAsTemplateOrTemplatePattern());
     break;
diff --git a/clang/lib/Lex/LiteralSupport.cpp b/clang/lib/Lex/LiteralSupport.cpp
index 3f2af1a74e5..fa0815eb9c6 100644
--- a/clang/lib/Lex/LiteralSupport.cpp
+++ b/clang/lib/Lex/LiteralSupport.cpp
@@ -693,7 +693,7 @@ NumericLiteralParser::NumericLiteralParser(StringRef TokSpelling,
           break;
         }
       }
-      // fall through.
+      LLVM_FALLTHROUGH;
     case 'j':
     case 'J':
       if (isImaginary) break;   // Cannot be repeated.
diff --git a/clang/lib/Parse/ParseCXXInlineMethods.cpp b/clang/lib/Parse/ParseCXXInlineMethods.cpp
index 5898120cab4..848a09bb446 100644
--- a/clang/lib/Parse/ParseCXXInlineMethods.cpp
+++ b/clang/lib/Parse/ParseCXXInlineMethods.cpp
@@ -728,7 +728,7 @@ bool Parser::ConsumeAndStoreUntil(tok::TokenKind T1, tok::TokenKind T2,
     case tok::semi:
       if (StopAtSemi)
         return false;
-      // FALL THROUGH.
+      LLVM_FALLTHROUGH;
     default:
       // consume this token.
       Toks.push_back(Tok);
@@ -1108,13 +1108,13 @@ bool Parser::ConsumeAndStoreInitializer(CachedTokens &Toks,
         goto consume_token;
       if (AngleCount) --AngleCount;
       if (KnownTemplateCount) --KnownTemplateCount;
-      // Fall through.
+      LLVM_FALLTHROUGH;
     case tok::greatergreater:
       if (!getLangOpts().CPlusPlus11)
         goto consume_token;
       if (AngleCount) --AngleCount;
       if (KnownTemplateCount) --KnownTemplateCount;
-      // Fall through.
+      LLVM_FALLTHROUGH;
     case tok::greater:
       if (AngleCount) --AngleCount;
       if (KnownTemplateCount) --KnownTemplateCount;
@@ -1219,7 +1219,7 @@ bool Parser::ConsumeAndStoreInitializer(CachedTokens &Toks,
     case tok::semi:
       if (CIK == CIK_DefaultInitializer)
         return true; // End of the default initializer.
-      // FALL THROUGH.
+      LLVM_FALLTHROUGH;
     default:
     consume_token:
       Toks.push_back(Tok);
diff --git a/clang/lib/Parse/ParseDecl.cpp b/clang/lib/Parse/ParseDecl.cpp
index af7bbfc94e8..af6214cdf66 100644
--- a/clang/lib/Parse/ParseDecl.cpp
+++ b/clang/lib/Parse/ParseDecl.cpp
@@ -4661,7 +4661,7 @@ bool Parser::isTypeSpecifierQualifier() {
   case tok::identifier:   // foo::bar
     if (TryAltiVecVectorToken())
       return true;
-    // Fall through.
+    LLVM_FALLTHROUGH;
   case tok::kw_typename:  // typename T::type
     // Annotate typenames and C++ scope specifiers.  If we get one, just
     // recurse to handle whatever we get.
@@ -4795,7 +4795,7 @@ bool Parser::isDeclarationSpecifier(bool DisambiguatingWithExpression) {
       return false;
     if (TryAltiVecVectorToken())
       return true;
-    // Fall through.
+    LLVM_FALLTHROUGH;
   case tok::kw_decltype: // decltype(T())::type
   case tok::kw_typename: // typename T::type
     // Annotate typenames and C++ scope specifiers.  If we get one, just
diff --git a/clang/lib/Parse/ParseDeclCXX.cpp b/clang/lib/Parse/ParseDeclCXX.cpp
index 52d19d78b65..9369f0f56c9 100644
--- a/clang/lib/Parse/ParseDeclCXX.cpp
+++ b/clang/lib/Parse/ParseDeclCXX.cpp
@@ -365,7 +365,7 @@ Decl *Parser::ParseLinkage(ParsingDeclSpec &DS, DeclaratorContext Context) {
     case tok::r_brace:
       if (!NestedModules)
         break;
-      // Fall through.
+      LLVM_FALLTHROUGH;
     default:
       ParsedAttributesWithRange attrs(AttrFactory);
       MaybeParseCXX11Attributes(attrs);
diff --git a/clang/lib/Parse/ParseExpr.cpp b/clang/lib/Parse/ParseExpr.cpp
index a322a81aafb..556bbaeedb0 100644
--- a/clang/lib/Parse/ParseExpr.cpp
+++ b/clang/lib/Parse/ParseExpr.cpp
@@ -1175,7 +1175,7 @@ ExprResult Parser::ParseCastExpression(bool isUnaryExpression,
   case tok::kw__Alignof:   // unary-expression: '_Alignof' '(' type-name ')'
     if (!getLangOpts().C11)
       Diag(Tok, diag::ext_c11_alignment) << Tok.getName();
-    // fallthrough
+    LLVM_FALLTHROUGH;
   case tok::kw_alignof:    // unary-expression: 'alignof' '(' type-id ')'
   case tok::kw___alignof:  // unary-expression: '__alignof' unary-expression
                            // unary-expression: '__alignof' '(' type-name ')'
@@ -1241,7 +1241,7 @@ ExprResult Parser::ParseCastExpression(bool isUnaryExpression,
                                            Ty.get(), nullptr);
       break;
     }
-    // Fall through
+    LLVM_FALLTHROUGH;
 
   case tok::annot_decltype:
   case tok::kw_char:
@@ -1447,7 +1447,7 @@ ExprResult Parser::ParseCastExpression(bool isUnaryExpression,
       Res = ParseObjCMessageExpression();
       break;
     }
-    // FALL THROUGH.
+    LLVM_FALLTHROUGH;
   default:
     NotCastExpr = true;
     return ExprError();
diff --git a/clang/lib/Parse/ParseTentative.cpp b/clang/lib/Parse/ParseTentative.cpp
index 349434fb8a8..de39e0675fd 100644
--- a/clang/lib/Parse/ParseTentative.cpp
+++ b/clang/lib/Parse/ParseTentative.cpp
@@ -159,7 +159,7 @@ Parser::TPResult Parser::TryConsumeDeclarationSpecifier() {
       ConsumeToken();
       break;
     }
-    // Fall through.
+    LLVM_FALLTHROUGH;
   case tok::kw_typeof:
   case tok::kw___attribute:
   case tok::kw___underlying_type: {
@@ -219,7 +219,7 @@ Parser::TPResult Parser::TryConsumeDeclarationSpecifier() {
 
   case tok::annot_cxxscope:
     ConsumeAnnotationToken();
-    // Fall through.
+    LLVM_FALLTHROUGH;
   default:
     ConsumeAnyToken();
 
@@ -1352,8 +1352,8 @@ Parser::isCXXDeclarationSpecifier(Parser::TPResult BracedCastResult,
     if (Next.isOneOf(tok::kw_new,       // ::new
                      tok::kw_delete))   // ::delete
       return TPResult::False;
+    LLVM_FALLTHROUGH;
   }
-    // Fall through.
   case tok::kw___super:
   case tok::kw_decltype:
     // Annotate typenames and C++ scope specifiers.  If we get one, just
diff --git a/clang/lib/Parse/Parser.cpp b/clang/lib/Parse/Parser.cpp
index 27a8172564b..9b492fc5a6a 100644
--- a/clang/lib/Parse/Parser.cpp
+++ b/clang/lib/Parse/Parser.cpp
@@ -341,7 +341,7 @@ bool Parser::SkipUntil(ArrayRef<tok::TokenKind> Toks, SkipUntilFlags Flags) {
     case tok::semi:
       if (HasFlagsSet(Flags, StopAtSemi))
         return false;
-      // FALL THROUGH.
+      LLVM_FALLTHROUGH;
     default:
       // Skip this token.
       ConsumeAnyToken();
@@ -1594,7 +1594,7 @@ Parser::TryAnnotateName(bool IsAddressOfOperand,
         AnnotateScopeToken(SS, !WasScopeAnnotation);
       return ANK_TemplateName;
     }
-    // Fall through.
+    LLVM_FALLTHROUGH;
   case Sema::NC_VarTemplate:
   case Sema::NC_FunctionTemplate: {
     // We have a type, variable or function template followed by '<'.
diff --git a/clang/lib/Rewrite/HTMLRewrite.cpp b/clang/lib/Rewrite/HTMLRewrite.cpp
index 12d7a16a2fc..2088d4571aa 100644
--- a/clang/lib/Rewrite/HTMLRewrite.cpp
+++ b/clang/lib/Rewrite/HTMLRewrite.cpp
@@ -477,7 +477,7 @@ void html::SyntaxHighlight(Rewriter &R, FileID FID, const Preprocessor &PP) {
       // Chop off the L, u, U or 8 prefix
       ++TokOffs;
       --TokLen;
-      // FALL THROUGH.
+      LLVM_FALLTHROUGH;
     case tok::string_literal:
       // FIXME: Exclude the optional ud-suffix from the highlighted range.
       HighlightRange(RB, TokOffs, TokOffs+TokLen, BufferStart,
diff --git a/clang/lib/Sema/SemaTemplateInstantiate.cpp b/clang/lib/Sema/SemaTemplateInstantiate.cpp
index b409844c1a4..8dde68f16e3 100644
--- a/clang/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiate.cpp
@@ -675,7 +675,7 @@ Optional<TemplateDeductionInfo *> Sema::isSFINAEContext() const {
       // context, depending on what else is on the stack.
       if (isa<TypeAliasTemplateDecl>(Active->Entity))
         break;
-      // Fall through.
+      LLVM_FALLTHROUGH;
     case CodeSynthesisContext::DefaultFunctionArgumentInstantiation:
     case CodeSynthesisContext::ExceptionSpecInstantiation:
       // This is a template instantiation, so there is no SFINAE.
diff --git a/clang/lib/Sema/SemaTemplateVariadic.cpp b/clang/lib/Sema/SemaTemplateVariadic.cpp
index 7d1d4c5d7e7..3338cec5eb1 100644
--- a/clang/lib/Sema/SemaTemplateVariadic.cpp
+++ b/clang/lib/Sema/SemaTemplateVariadic.cpp
@@ -976,6 +976,7 @@ ExprResult Sema::ActOnSizeofParameterPackExpr(Scope *S,
                    PDiag(diag::note_parameter_pack_here));
       ParameterPack = Corrected.getCorrectionDecl();
     }
+    break;
 
   case LookupResult::FoundOverloaded:
   case LookupResult::FoundUnresolvedValue:
diff --git a/clang/lib/StaticAnalyzer/Checkers/RetainCountChecker/RetainCountChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/RetainCountChecker/RetainCountChecker.cpp
index 3431b1554a1..febeffda1b8 100644
--- a/clang/lib/StaticAnalyzer/Checkers/RetainCountChecker/RetainCountChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/RetainCountChecker/RetainCountChecker.cpp
@@ -628,7 +628,7 @@ RetainCountChecker::updateSymbol(ProgramStateRef state, SymbolRef sym,
         break;
       }
 
-      // Fall-through.
+      LLVM_FALLTHROUGH;
 
     case DoNothing:
       return state;
diff --git a/clang/lib/StaticAnalyzer/Core/BugReporter.cpp b/clang/lib/StaticAnalyzer/Core/BugReporter.cpp
index 9bc6ff0d268..2b6bbebd0e9 100644
--- a/clang/lib/StaticAnalyzer/Core/BugReporter.cpp
+++ b/clang/lib/StaticAnalyzer/Core/BugReporter.cpp
@@ -842,7 +842,7 @@ static void reversePropagateIntererstingSymbols(BugReport &R,
     default:
       if (!isa<CastExpr>(Ex))
         break;
-      // Fall through.
+      LLVM_FALLTHROUGH;
     case Stmt::BinaryOperatorClass:
     case Stmt::UnaryOperatorClass: {
       for (const Stmt *SubStmt : Ex->children()) {
diff --git a/clang/lib/StaticAnalyzer/Core/ExprEngineC.cpp b/clang/lib/StaticAnalyzer/Core/ExprEngineC.cpp
index b3700a1ef7e..74345b5eba8 100644
--- a/clang/lib/StaticAnalyzer/Core/ExprEngineC.cpp
+++ b/clang/lib/StaticAnalyzer/Core/ExprEngineC.cpp
@@ -962,7 +962,7 @@ void ExprEngine::VisitUnaryOperator(const UnaryOperator* U, ExplodedNode *Pred,
     }
     case UO_Plus:
       assert(!U->isGLValue());
-      // FALL-THROUGH.
+      LLVM_FALLTHROUGH;
     case UO_Deref:
     case UO_Extension: {
       handleUOExtension(I, U, Bldr);
diff --git a/clang/lib/StaticAnalyzer/Core/ExprEngineCXX.cpp b/clang/lib/StaticAnalyzer/Core/ExprEngineCXX.cpp
index 933d54e11c8..01606d14064 100644
--- a/clang/lib/StaticAnalyzer/Core/ExprEngineCXX.cpp
+++ b/clang/lib/StaticAnalyzer/Core/ExprEngineCXX.cpp
@@ -426,7 +426,7 @@ void ExprEngine::VisitCXXConstructExpr(const CXXConstructExpr *CE,
         }
       }
     }
-    // FALLTHROUGH
+    LLVM_FALLTHROUGH;
   case CXXConstructExpr::CK_NonVirtualBase:
     // In C++17, classes with non-virtual bases may be aggregates, so they would
     // be initialized as aggregates without a constructor call, so we may have
@@ -445,7 +445,7 @@ void ExprEngine::VisitCXXConstructExpr(const CXXConstructExpr *CE,
       CallOpts.IsCtorOrDtorWithImproperlyModeledTargetRegion = true;
       break;
     }
-    // FALLTHROUGH
+    LLVM_FALLTHROUGH;
   case CXXConstructExpr::CK_Delegating: {
     const CXXMethodDecl *CurCtor = cast<CXXMethodDecl>(LCtx->getDecl());
     Loc ThisPtr = getSValBuilder().getCXXThis(CurCtor,
diff --git a/clang/lib/StaticAnalyzer/Core/RegionStore.cpp b/clang/lib/StaticAnalyzer/Core/RegionStore.cpp
index aa3b4044dca..98d11fa39ce 100644
--- a/clang/lib/StaticAnalyzer/Core/RegionStore.cpp
+++ b/clang/lib/StaticAnalyzer/Core/RegionStore.cpp
@@ -1330,11 +1330,11 @@ RegionStoreManager::invalidateRegions(Store store,
   case GFK_All:
     B = invalidateGlobalRegion(MemRegion::GlobalInternalSpaceRegionKind,
                                Ex, Count, LCtx, B, Invalidated);
-    // FALLTHROUGH
+    LLVM_FALLTHROUGH;
   case GFK_SystemOnly:
     B = invalidateGlobalRegion(MemRegion::GlobalSystemSpaceRegionKind,
                                Ex, Count, LCtx, B, Invalidated);
-    // FALLTHROUGH
+    LLVM_FALLTHROUGH;
   case GFK_None:
     break;
   }
diff --git a/clang/lib/StaticAnalyzer/Core/SimpleSValBuilder.cpp b/clang/lib/StaticAnalyzer/Core/SimpleSValBuilder.cpp
index 36a0f4e6d8c..5cd9320d650 100644
--- a/clang/lib/StaticAnalyzer/Core/SimpleSValBuilder.cpp
+++ b/clang/lib/StaticAnalyzer/Core/SimpleSValBuilder.cpp
@@ -624,7 +624,7 @@ SVal SimpleSValBuilder::evalBinOpNN(ProgramStateRef state,
       case BO_LE:
       case BO_GE:
         op = BinaryOperator::reverseComparisonOp(op);
-        // FALL-THROUGH
+        LLVM_FALLTHROUGH;
       case BO_EQ:
       case BO_NE:
       case BO_Add:
@@ -638,7 +638,7 @@ SVal SimpleSValBuilder::evalBinOpNN(ProgramStateRef state,
         // (~0)>>a
         if (LHSValue.isAllOnesValue() && LHSValue.isSigned())
           return evalCastFromNonLoc(lhs, resultTy);
-        // FALL-THROUGH
+        LLVM_FALLTHROUGH;
       case BO_Shl:
         // 0<<a and 0>>a
         if (LHSValue == 0)
diff --git a/clang/tools/clang-func-mapping/ClangFnMapGen.cpp b/clang/tools/clang-func-mapping/ClangFnMapGen.cpp
index 50c7c740672..8adc1fada55 100644
--- a/clang/tools/clang-func-mapping/ClangFnMapGen.cpp
+++ b/clang/tools/clang-func-mapping/ClangFnMapGen.cpp
@@ -82,6 +82,7 @@ void MapFunctionNamesConsumer::handleDecl(const Decl *D) {
         case UniqueExternalLinkage:
           if (SM.isInMainFile(Body->getBeginLoc()))
             Index[LookupName] = CurrentFileName;
+          break;
         default:
           break;
         }
diff --git a/lld/lib/ReaderWriter/MachO/ArchHandler_x86_64.cpp b/lld/lib/ReaderWriter/MachO/ArchHandler_x86_64.cpp
index 8cb6710857e..fba3d530e48 100644
--- a/lld/lib/ReaderWriter/MachO/ArchHandler_x86_64.cpp
+++ b/lld/lib/ReaderWriter/MachO/ArchHandler_x86_64.cpp
@@ -80,6 +80,7 @@ public:
     switch (ref->kindValue()) {
     case ripRel32Got:
       assert(targetNowGOT && "target must be GOT");
+      LLVM_FALLTHROUGH;
     case ripRel32GotLoad:
       const_cast<Reference *>(ref)
         ->setKindValue(targetNowGOT ? ripRel32 : ripRel32GotLoadNowLea);
diff --git a/lld/lib/ReaderWriter/MachO/MachOLinkingContext.cpp b/lld/lib/ReaderWriter/MachO/MachOLinkingContext.cpp
index ce423d03aae..61583963ddd 100644
--- a/lld/lib/ReaderWriter/MachO/MachOLinkingContext.cpp
+++ b/lld/lib/ReaderWriter/MachO/MachOLinkingContext.cpp
@@ -262,6 +262,7 @@ void MachOLinkingContext::configure(HeaderFileType type, Arch arch, OS os,
   case llvm::MachO::MH_OBJECT:
     _printRemainingUndefines = false;
     _allowRemainingUndefines = true;
+    break;
   default:
     break;
   }
diff --git a/lldb/source/Plugins/SymbolFile/PDB/PDBASTParser.cpp b/lldb/source/Plugins/SymbolFile/PDB/PDBASTParser.cpp
index 96795ff4b0e..b97ac1b498c 100644
--- a/lldb/source/Plugins/SymbolFile/PDB/PDBASTParser.cpp
+++ b/lldb/source/Plugins/SymbolFile/PDB/PDBASTParser.cpp
@@ -288,6 +288,7 @@ GetClassOrFunctionParent(const llvm::pdb::PDBSymbol &symbol) {
     auto class_parent_id = raw.getClassParentId();
     if (auto class_parent = session.getSymbolById(class_parent_id))
       return class_parent;
+    break;
   }
   default:
     break;
diff --git a/lldb/tools/lldb-test/lldb-test.cpp b/lldb/tools/lldb-test/lldb-test.cpp
index 3ab6dd01a13..e8d3363b52f 100644
--- a/lldb/tools/lldb-test/lldb-test.cpp
+++ b/lldb/tools/lldb-test/lldb-test.cpp
@@ -285,7 +285,7 @@ std::string opts::breakpoint::substitute(StringRef Cmd) {
         OS << sys::path::parent_path(breakpoint::CommandFile);
         break;
       }
-      // fall through
+      LLVM_FALLTHROUGH;
     default:
       size_t pos = Cmd.find('%');
       OS << Cmd.substr(0, pos);
diff --git a/llvm/include/llvm/Demangle/ItaniumDemangle.h b/llvm/include/llvm/Demangle/ItaniumDemangle.h
index a465921843f..c5619a15bbe 100644
--- a/llvm/include/llvm/Demangle/ItaniumDemangle.h
+++ b/llvm/include/llvm/Demangle/ItaniumDemangle.h
@@ -2807,6 +2807,7 @@ AbstractManglingParser<Derived, Alloc>::parseCtorDtorName(Node *&SoFar,
       SoFar = make<ExpandedSpecialSubstitution>(SSK);
       if (!SoFar)
         return nullptr;
+      break;
     default:
       break;
     }
diff --git a/llvm/lib/Analysis/InlineCost.cpp b/llvm/lib/Analysis/InlineCost.cpp
index 1b5150a0d18..923dbe59e86 100644
--- a/llvm/lib/Analysis/InlineCost.cpp
+++ b/llvm/lib/Analysis/InlineCost.cpp
@@ -720,6 +720,7 @@ bool CallAnalyzer::visitCastInst(CastInst &I) {
   case Instruction::FPToSI:
     if (TTI.getFPOpCost(I.getType()) == TargetTransformInfo::TCC_Expensive)
       Cost += InlineConstants::CallPenalty;
+    break;
   default:
     break;
   }
diff --git a/llvm/lib/Demangle/MicrosoftDemangleNodes.cpp b/llvm/lib/Demangle/MicrosoftDemangleNodes.cpp
index d5ee47761bd..af893b9b68e 100644
--- a/llvm/lib/Demangle/MicrosoftDemangleNodes.cpp
+++ b/llvm/lib/Demangle/MicrosoftDemangleNodes.cpp
@@ -558,6 +558,7 @@ void VariableSymbolNode::output(OutputStream &OS, OutputFlags Flags) const {
   case StorageClass::PublicStatic:
   case StorageClass::ProtectedStatic:
     OS << "static ";
+    break;
   default:
     break;
   }
diff --git a/llvm/lib/Target/AMDGPU/AMDGPURegisterBankInfo.cpp b/llvm/lib/Target/AMDGPU/AMDGPURegisterBankInfo.cpp
index 8314b4a490f..05b714f924b 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPURegisterBankInfo.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPURegisterBankInfo.cpp
@@ -351,7 +351,7 @@ AMDGPURegisterBankInfo::getInstrMapping(const MachineInstr &MI) const {
   case AMDGPU::G_SHL:
     if (isSALUMapping(MI))
       return getDefaultMappingSOP(MI);
-    // Fall-through
+    LLVM_FALLTHROUGH;
 
   case AMDGPU::G_FADD:
   case AMDGPU::G_FPTOSI:
diff --git a/llvm/lib/Target/AMDGPU/R600MachineScheduler.cpp b/llvm/lib/Target/AMDGPU/R600MachineScheduler.cpp
index 478a473a51b..7769a35aadc 100644
--- a/llvm/lib/Target/AMDGPU/R600MachineScheduler.cpp
+++ b/llvm/lib/Target/AMDGPU/R600MachineScheduler.cpp
@@ -236,6 +236,7 @@ R600SchedStrategy::AluKind R600SchedStrategy::getAluKind(SUnit *SU) const {
       // MI will become a KILL, don't considers it in scheduling
       return AluDiscarded;
     }
+    break;
   default:
     break;
   }
diff --git a/llvm/lib/Target/AMDGPU/SIISelLowering.cpp b/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
index e41cf6e771b..66eb9bbb84c 100644
--- a/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
+++ b/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
@@ -5049,12 +5049,11 @@ SDValue SITargetLowering::LowerINTRINSIC_WO_CHAIN(SDValue Op,
   case Intrinsic::r600_read_tgid_z:
     return getPreloadedValue(DAG, *MFI, VT,
                              AMDGPUFunctionArgInfo::WORKGROUP_ID_Z);
-  case Intrinsic::amdgcn_workitem_id_x: {
+  case Intrinsic::amdgcn_workitem_id_x:
   case Intrinsic::r600_read_tidig_x:
     return loadInputValue(DAG, &AMDGPU::VGPR_32RegClass, MVT::i32,
                           SDLoc(DAG.getEntryNode()),
                           MFI->getArgInfo().WorkItemIDX);
-  }
   case Intrinsic::amdgcn_workitem_id_y:
   case Intrinsic::r600_read_tidig_y:
     return loadInputValue(DAG, &AMDGPU::VGPR_32RegClass, MVT::i32,
diff --git a/llvm/lib/Target/BPF/AsmParser/BPFAsmParser.cpp b/llvm/lib/Target/BPF/AsmParser/BPFAsmParser.cpp
index 496f2befde5..8890fb8adf4 100644
--- a/llvm/lib/Target/BPF/AsmParser/BPFAsmParser.cpp
+++ b/llvm/lib/Target/BPF/AsmParser/BPFAsmParser.cpp
@@ -357,8 +357,8 @@ BPFAsmParser::parseOperandAsOperator(OperandVector &Operands) {
   case AsmToken::Plus: {
     if (getLexer().peekTok().is(AsmToken::Integer))
       return MatchOperand_NoMatch;
+    LLVM_FALLTHROUGH;
   }
-  // Fall through.
 
   case AsmToken::Equal:
   case AsmToken::Greater:
diff --git a/llvm/lib/Target/Hexagon/HexagonConstExtenders.cpp b/llvm/lib/Target/Hexagon/HexagonConstExtenders.cpp
index 424be5e4476..ba9f638796e 100644
--- a/llvm/lib/Target/Hexagon/HexagonConstExtenders.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonConstExtenders.cpp
@@ -1208,6 +1208,7 @@ void HCE::recordExtender(MachineInstr &MI, unsigned OpNum) {
       case Hexagon::S4_subaddi:       // (__: ## - Rs<<0)
         ED.Expr.Rs = MI.getOperand(OpNum+1);
         ED.Expr.Neg = true;
+        break;
       default:                        // (__: ## + __<<_)
         break;
     }
diff --git a/llvm/lib/Target/Hexagon/HexagonConstPropagation.cpp b/llvm/lib/Target/Hexagon/HexagonConstPropagation.cpp
index 8f22a71dc1f..fa192391313 100644
--- a/llvm/lib/Target/Hexagon/HexagonConstPropagation.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonConstPropagation.cpp
@@ -2463,6 +2463,7 @@ APInt HexagonConstEvaluator::getCmpImm(unsigned Opc, unsigned OpX,
     case Hexagon::A4_cmpheqi:    // s8
     case Hexagon::C4_cmpneqi:   // s8
       Signed = true;
+      break;
     case Hexagon::A4_cmpbeqi:    // u8
       break;
     case Hexagon::C2_cmpgtui:      // u9
diff --git a/llvm/lib/Target/Hexagon/HexagonISelDAGToDAG.cpp b/llvm/lib/Target/Hexagon/HexagonISelDAGToDAG.cpp
index 9a66aece579..470b05bda4c 100644
--- a/llvm/lib/Target/Hexagon/HexagonISelDAGToDAG.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonISelDAGToDAG.cpp
@@ -1547,6 +1547,7 @@ bool HexagonDAGToDAGISel::keepsLowBits(const SDValue &Val, unsigned NumBits,
         return true;
       }
     }
+    break;
   }
   default:
     break;
diff --git a/llvm/lib/Target/Hexagon/HexagonMachineScheduler.cpp b/llvm/lib/Target/Hexagon/HexagonMachineScheduler.cpp
index ebfe21bd17d..908ce24136c 100644
--- a/llvm/lib/Target/Hexagon/HexagonMachineScheduler.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonMachineScheduler.cpp
@@ -105,6 +105,7 @@ bool VLIWResourceModel::isResourceAvailable(SUnit *SU, bool IsTop) {
   default:
     if (!ResourcesModel->canReserveResources(*SU->getInstr()))
       return false;
+    break;
   case TargetOpcode::EXTRACT_SUBREG:
   case TargetOpcode::INSERT_SUBREG:
   case TargetOpcode::SUBREG_TO_REG:
diff --git a/llvm/lib/Target/Hexagon/HexagonVLIWPacketizer.cpp b/llvm/lib/Target/Hexagon/HexagonVLIWPacketizer.cpp
index 93b5bedbb38..722699907ca 100644
--- a/llvm/lib/Target/Hexagon/HexagonVLIWPacketizer.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonVLIWPacketizer.cpp
@@ -1568,6 +1568,7 @@ bool HexagonPacketizerList::isLegalToPacketizeTogether(SUnit *SUI, SUnit *SUJ) {
             if (GlueAllocframeStore)
               continue;
           }
+          break;
         default:
           break;
       }
diff --git a/llvm/lib/Target/Mips/AsmParser/MipsAsmParser.cpp b/llvm/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
index 2e70d35fc4a..79e0c001a63 100644
--- a/llvm/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
+++ b/llvm/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
@@ -767,13 +767,13 @@ public:
 
   ~MipsOperand() override {
     switch (Kind) {
-    case k_Immediate:
-      break;
     case k_Memory:
       delete Mem.Base;
       break;
     case k_RegList:
       delete RegList.List;
+      break;
+    case k_Immediate:
     case k_RegisterIndex:
     case k_Token:
       break;
diff --git a/llvm/lib/Target/Mips/MipsAsmPrinter.cpp b/llvm/lib/Target/Mips/MipsAsmPrinter.cpp
index 2e0c25de2bc..a19c97e2ef0 100644
--- a/llvm/lib/Target/Mips/MipsAsmPrinter.cpp
+++ b/llvm/lib/Target/Mips/MipsAsmPrinter.cpp
@@ -561,6 +561,7 @@ bool MipsAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNum,
         O << '$' << MipsInstPrinter::getRegisterName(Reg);
         return false;
       }
+      break;
     }
     case 'w':
       // Print MSA registers for the 'f' constraint
diff --git a/llvm/lib/Target/Mips/MipsSEISelDAGToDAG.cpp b/llvm/lib/Target/Mips/MipsSEISelDAGToDAG.cpp
index cf2899dd375..f030f83295d 100644
--- a/llvm/lib/Target/Mips/MipsSEISelDAGToDAG.cpp
+++ b/llvm/lib/Target/Mips/MipsSEISelDAGToDAG.cpp
@@ -244,7 +244,7 @@ void MipsSEDAGToDAGISel::processFunctionAfterISel(MachineFunction &MF) {
           MI.addOperand(MachineOperand::CreateReg(Mips::SP, false, true));
           break;
         }
-      // fallthrough
+        LLVM_FALLTHROUGH;
       case Mips::BuildPairF64:
       case Mips::ExtractElementF64:
         if (Subtarget->isABI_FPXX() && !Subtarget->hasMTHC1())
diff --git a/llvm/lib/Target/PowerPC/PPCFastISel.cpp b/llvm/lib/Target/PowerPC/PPCFastISel.cpp
index f212894035d..668169839e7 100644
--- a/llvm/lib/Target/PowerPC/PPCFastISel.cpp
+++ b/llvm/lib/Target/PowerPC/PPCFastISel.cpp
@@ -903,7 +903,7 @@ bool PPCFastISel::PPCEmitCmp(const Value *SrcValue1, const Value *SrcValue2,
     case MVT::i8:
     case MVT::i16:
       NeedsExt = true;
-      // Intentional fall-through.
+      LLVM_FALLTHROUGH;
     case MVT::i32:
       if (!UseImm)
         CmpOpc = IsZExt ? PPC::CMPLW : PPC::CMPW;
diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
index 4ed110e6663..c6f0212ab40 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -3970,7 +3970,7 @@ SDValue PPCTargetLowering::LowerFormalArguments_64SVR4(
 
       assert(ObjectVT.getSimpleVT().SimpleTy == MVT::v4f32 &&
              "Invalid QPX parameter type");
-      /* fall through */
+      LLVM_FALLTHROUGH;
 
     case MVT::v4f64:
     case MVT::v4i1:
@@ -6113,7 +6113,7 @@ SDValue PPCTargetLowering::LowerCall_64SVR4(
       assert(Arg.getValueType().getSimpleVT().SimpleTy == MVT::v4f32 &&
              "Invalid QPX parameter type");
 
-      /* fall through */
+      LLVM_FALLTHROUGH;
     case MVT::v4f64:
     case MVT::v4i1: {
       bool IsF32 = Arg.getValueType().getSimpleVT().SimpleTy == MVT::v4f32;
diff --git a/llvm/lib/Target/SystemZ/SystemZISelDAGToDAG.cpp b/llvm/lib/Target/SystemZ/SystemZISelDAGToDAG.cpp
index c8474b15b18..0d2c2389847 100644
--- a/llvm/lib/Target/SystemZ/SystemZISelDAGToDAG.cpp
+++ b/llvm/lib/Target/SystemZ/SystemZISelDAGToDAG.cpp
@@ -1308,7 +1308,7 @@ bool SystemZDAGToDAGISel::tryFoldLoadStoreIntoMemOperand(SDNode *Node) {
     return false;
   case SystemZISD::SSUBO:
     NegateOperand = true;
-    /* fall through */
+    LLVM_FALLTHROUGH;
   case SystemZISD::SADDO:
     if (MemVT == MVT::i32)
       NewOpc = SystemZ::ASI;
@@ -1319,7 +1319,7 @@ bool SystemZDAGToDAGISel::tryFoldLoadStoreIntoMemOperand(SDNode *Node) {
     break;
   case SystemZISD::USUBO:
     NegateOperand = true;
-    /* fall through */
+    LLVM_FALLTHROUGH;
   case SystemZISD::UADDO:
     if (MemVT == MVT::i32)
       NewOpc = SystemZ::ALSI;
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyFastISel.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyFastISel.cpp
index 5611a1b4588..00e37a4af29 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyFastISel.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyFastISel.cpp
@@ -447,6 +447,7 @@ unsigned WebAssemblyFastISel::zeroExtendToI32(unsigned Reg, const Value *V,
           (isa<Argument>(V) && cast<Argument>(V)->hasZExtAttr()))
         return copyValue(Reg);
     }
+    break;
   case MVT::i8:
   case MVT::i16:
     break;
diff --git a/llvm/lib/Target/X86/Disassembler/X86DisassemblerDecoder.cpp b/llvm/lib/Target/X86/Disassembler/X86DisassemblerDecoder.cpp
index b6320bd0612..54d550b6065 100644
--- a/llvm/lib/Target/X86/Disassembler/X86DisassemblerDecoder.cpp
+++ b/llvm/lib/Target/X86/Disassembler/X86DisassemblerDecoder.cpp
@@ -1393,7 +1393,7 @@ static int readModRM(struct InternalInstruction* insn) {
       break;
     case 0x1:
       insn->displacementSize = 1;
-      /* FALLTHROUGH */
+      LLVM_FALLTHROUGH;
     case 0x2:
       insn->eaDisplacement = (mod == 0x1 ? EA_DISP_8 : EA_DISP_32);
       switch (rm & 7) {
diff --git a/polly/lib/Analysis/ScopBuilder.cpp b/polly/lib/Analysis/ScopBuilder.cpp
index fe55c596058..7d1e781ab34 100644
--- a/polly/lib/Analysis/ScopBuilder.cpp
+++ b/polly/lib/Analysis/ScopBuilder.cpp
@@ -579,7 +579,7 @@ bool ScopBuilder::buildAccessCallInst(MemAccInst Inst, ScopStmt *Stmt) {
     return true;
   case FMRB_OnlyReadsArgumentPointees:
     ReadOnly = true;
-  // Fall through
+    LLVM_FALLTHROUGH;
   case FMRB_OnlyAccessesArgumentPointees: {
     auto AccType = ReadOnly ? MemoryAccess::READ : MemoryAccess::MAY_WRITE;
     Loop *L = LI.getLoopFor(Inst->getParent());
@@ -1216,7 +1216,7 @@ static MemoryAccess::ReductionType getReductionType(const BinaryOperator *BinOp,
   case Instruction::FAdd:
     if (!BinOp->isFast())
       return MemoryAccess::RT_NONE;
-    // Fall through
+    LLVM_FALLTHROUGH;
   case Instruction::Add:
     return MemoryAccess::RT_ADD;
   case Instruction::Or:
@@ -1228,7 +1228,7 @@ static MemoryAccess::ReductionType getReductionType(const BinaryOperator *BinOp,
   case Instruction::FMul:
     if (!BinOp->isFast())
       return MemoryAccess::RT_NONE;
-    // Fall through
+    LLVM_FALLTHROUGH;
   case Instruction::Mul:
     if (DisableMultiplicativeReductions)
       return MemoryAccess::RT_NONE;
diff --git a/polly/lib/Analysis/ScopDetection.cpp b/polly/lib/Analysis/ScopDetection.cpp
index 9502f324fc9..23b714dc098 100644
--- a/polly/lib/Analysis/ScopDetection.cpp
+++ b/polly/lib/Analysis/ScopDetection.cpp
@@ -779,7 +779,7 @@ bool ScopDetection::isValidIntrinsicInst(IntrinsicInst &II,
       if (!isValidAccess(&II, AF, BP, Context))
         return false;
     }
-  // Fall through
+    LLVM_FALLTHROUGH;
   case Intrinsic::memset:
     AF = SE.getSCEVAtScope(cast<MemIntrinsic>(II).getDest(), L);
     if (!AF->isZero()) {