Serialize `#pragma comment`.

[thakis]

Summary

#pragma comment was handled by Sema calling a function on ASTConsumer, and CodeGen then implementing this function and writing things to its output.

Instead, introduce a PragmaCommentDecl AST node and hang one off the TranslationUnitDecl for every #pragma comment line, and then use the regular serialization machinery. (Since PragmaCommentDecl has codegen relevance, it's eagerly deserialized.)

[rnk]

lgtm

[thakis]

r262493, thanks!

[thakis]

Also landed a very similar change for the very similar detect_mismatch pragma in r262506. (The other missing serialized pragmas will use a different approach.)

include/clang/AST/ASTConsumer.h

public:
   /// The default implementation ignored them.
   virtual void HandleTopLevelDeclInObjCContainer(DeclGroupRef D);
 
   /// \brief Handle an ImportDecl that was implicitly created due to an
   /// inclusion directive.
   /// The default implementation passes it to HandleTopLevelDecl.
   virtual void HandleImplicitImportDecl(ImportDecl *D);
 
-  /// \brief Handle a pragma or command line flag that appends to Linker
-  /// Options.  This exists to support Microsoft's
-  /// #pragma comment(linker, "/foo") and the frontend flag --linker-option=.
-  virtual void HandleLinkerOption(llvm::StringRef Opts) {}
-
   /// \brief Handle a pragma that emits a mismatch identifier and value to the
   /// object file for the linker to work with.  Currently, this only exists to
   /// support Microsoft's #pragma detect_mismatch.
   virtual void HandleDetectMismatch(llvm::StringRef Name,
                                     llvm::StringRef Value) {}
 
-  /// \brief Handle a dependent library created by a pragma in the source.
-  /// Currently this only exists to support Microsoft's
-  /// #pragma comment(lib, "/foo").
-  virtual void HandleDependentLibrary(llvm::StringRef Lib) {}
-
   /// CompleteTentativeDefinition - Callback invoked at the end of a translation
   /// unit to notify the consumer that the given tentative definition should be
   /// completed.
   ///
   /// The variable declaration itself will be a tentative
   /// definition. If it had an incomplete array type, its type will
   /// have already been changed to an array of size 1. However, the
   /// declaration remains a tentative definition and has not been

include/clang/AST/Decl.h

 #include "clang/AST/DeclBase.h"
 #include "clang/AST/DeclarationName.h"
 #include "clang/AST/ExternalASTSource.h"
 #include "clang/AST/Redeclarable.h"
 #include "clang/AST/Type.h"
 #include "clang/Basic/Linkage.h"
 #include "clang/Basic/Module.h"
 #include "clang/Basic/OperatorKinds.h"
+#include "clang/Basic/PragmaKinds.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Support/TrailingObjects.h"
 
 namespace clang {
 struct ASTTemplateArgumentListInfo;
public:
   static DeclContext *castToDeclContext(const TranslationUnitDecl *D) {
     return static_cast<DeclContext *>(const_cast<TranslationUnitDecl*>(D));
   }
   static TranslationUnitDecl *castFromDeclContext(const DeclContext *DC) {
     return static_cast<TranslationUnitDecl *>(const_cast<DeclContext*>(DC));
   }
 };
 
+/// \brief Represents a `#pragma comment` line. Always a child of
+/// TranslationUnitDecl.
+class PragmaCommentDecl final
+    : public Decl,
+      private llvm::TrailingObjects<PragmaCommentDecl, char> {
+  virtual void anchor();
+
+  PragmaMSCommentKind CommentKind;
+
+  friend TrailingObjects;
+  friend class ASTDeclReader;
+  friend class ASTDeclWriter;
+
+  PragmaCommentDecl(TranslationUnitDecl *TU, SourceLocation CommentLoc,
+                    PragmaMSCommentKind CommentKind)
+      : Decl(PragmaComment, TU, CommentLoc), CommentKind(CommentKind) {}
+
+public:
+  static PragmaCommentDecl *Create(const ASTContext &C, TranslationUnitDecl *DC,
+                                   SourceLocation CommentLoc,
+                                   PragmaMSCommentKind CommentKind,
+                                   StringRef Arg);
+  static PragmaCommentDecl *CreateDeserialized(ASTContext &C, unsigned ID,
+                                               unsigned ArgSize);
+
+  PragmaMSCommentKind getCommentKind() const { return CommentKind; }
+
+  StringRef getArg() const { return getTrailingObjects<char>(); }
+
+  // Implement isa/cast/dyncast/etc.
+  static bool classof(const Decl *D) { return classofKind(D->getKind()); }
+  static bool classofKind(Kind K) { return K == PragmaComment; }
+};
+
 /// \brief Declaration context for names declared as extern "C" in C++. This
 /// is neither the semantic nor lexical context for such declarations, but is
 /// used to check for conflicts with other extern "C" declarations. Example:
 ///
 /// \code
 ///   namespace N { extern "C" void f(); } // #1
 ///   void N::f() {}                       // #2
 ///   namespace M { extern "C" void f(); } // #3

include/clang/AST/RecursiveASTVisitor.h

 
 DEF_TRAVERSE_DECL(
     TranslationUnitDecl,
     {// Code in an unnamed namespace shows up automatically in
      // decls_begin()/decls_end().  Thus we don't need to recurse on
      // D->getAnonymousNamespace().
     })
 
+DEF_TRAVERSE_DECL(PragmaCommentDecl, {})
+
 DEF_TRAVERSE_DECL(ExternCContextDecl, {})
 
 DEF_TRAVERSE_DECL(NamespaceAliasDecl, {
   TRY_TO(TraverseNestedNameSpecifierLoc(D->getQualifierLoc()));
 
   // We shouldn't traverse an aliased namespace, since it will be
   // defined (and, therefore, traversed) somewhere else.
   //

include/clang/Basic/DeclNodes.td

 class AttrSubject;
 
 class Decl<bit abstract = 0> : AttrSubject {
   bit Abstract = abstract;
 }
 
 class DDecl<Decl base, bit abstract = 0> : Decl<abstract> {
   Decl Base = base;
 }
 
 class DeclContext { }
 
 def TranslationUnit : Decl, DeclContext;
+def PragmaComment : Decl;
 def ExternCContext : Decl, DeclContext;
 def Named : Decl<1>;
   def Namespace : DDecl<Named>, DeclContext;
   def UsingDirective : DDecl<Named>;
   def NamespaceAlias : DDecl<Named>;
   def Label : DDecl<Named>;
   def Type : DDecl<Named, 1>;
     def TypedefName : DDecl<Type, 1>;

include/clang/Basic/PragmaKinds.h

+//===--- PragmaKinds.h - #pragma comment() kinds  ---------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_BASIC_PRAGMA_KINDS_H
+#define LLVM_CLANG_BASIC_PRAGMA_KINDS_H
+
+namespace clang {
+
+enum PragmaMSCommentKind {
+  PCK_Unknown,
+  PCK_Linker,   // #pragma comment(linker, ...)
+  PCK_Lib,      // #pragma comment(lib, ...)
+  PCK_Compiler, // #pragma comment(compiler, ...)
+  PCK_ExeStr,   // #pragma comment(exestr, ...)
+  PCK_User      // #pragma comment(user, ...)
+};
+
+}
+
+#endif

include/clang/Frontend/MultiplexConsumer.h

public:
   void HandleInlineMethodDefinition(CXXMethodDecl *D) override;
   void HandleInterestingDecl(DeclGroupRef D) override;
   void HandleTranslationUnit(ASTContext &Ctx) override;
   void HandleTagDeclDefinition(TagDecl *D) override;
   void HandleTagDeclRequiredDefinition(const TagDecl *D) override;
   void HandleCXXImplicitFunctionInstantiation(FunctionDecl *D) override;
   void HandleTopLevelDeclInObjCContainer(DeclGroupRef D) override;
   void HandleImplicitImportDecl(ImportDecl *D) override;
-  void HandleLinkerOption(llvm::StringRef Opts) override;
   void HandleDetectMismatch(llvm::StringRef Name,
                             llvm::StringRef Value) override;
-  void HandleDependentLibrary(llvm::StringRef Lib) override;
   void CompleteTentativeDefinition(VarDecl *D) override;
   void AssignInheritanceModel(CXXRecordDecl *RD) override;
   void HandleVTable(CXXRecordDecl *RD) override;
   ASTMutationListener *GetASTMutationListener() override;
   ASTDeserializationListener *GetASTDeserializationListener() override;
   void PrintStats() override;
   bool shouldSkipFunctionBody(Decl *D) override;
 

include/clang/Sema/Sema.h

 #include "clang/AST/MangleNumberingContext.h"
 #include "clang/AST/NSAPI.h"
 #include "clang/AST/PrettyPrinter.h"
 #include "clang/AST/TypeLoc.h"
 #include "clang/Basic/ExpressionTraits.h"
 #include "clang/Basic/LangOptions.h"
 #include "clang/Basic/Module.h"
 #include "clang/Basic/OpenMPKinds.h"
+#include "clang/Basic/PragmaKinds.h"
 #include "clang/Basic/Specifiers.h"
 #include "clang/Basic/TemplateKinds.h"
 #include "clang/Basic/TypeTraits.h"
 #include "clang/Sema/AnalysisBasedWarnings.h"
 #include "clang/Sema/DeclSpec.h"
 #include "clang/Sema/ExternalSemaSource.h"
 #include "clang/Sema/IdentifierResolver.h"
 #include "clang/Sema/ObjCMethodList.h"
enum PragmaPackKind {
     PPK_Pop      // #pragma pack(pop, [identifier], [n])
   };
 
   enum PragmaMSStructKind {
     PMSST_OFF,  // #pragms ms_struct off
     PMSST_ON    // #pragms ms_struct on
   };
 
-  enum PragmaMSCommentKind {
-    PCK_Unknown,
-    PCK_Linker,   // #pragma comment(linker, ...)
-    PCK_Lib,      // #pragma comment(lib, ...)
-    PCK_Compiler, // #pragma comment(compiler, ...)
-    PCK_ExeStr,   // #pragma comment(exestr, ...)
-    PCK_User      // #pragma comment(user, ...)
-  };
-
   /// ActOnPragmaPack - Called on well formed \#pragma pack(...).
   void ActOnPragmaPack(PragmaPackKind Kind,
                        IdentifierInfo *Name,
                        Expr *Alignment,
                        SourceLocation PragmaLoc,
                        SourceLocation LParenLoc,
                        SourceLocation RParenLoc);
 
   /// ActOnPragmaMSStruct - Called on well formed \#pragma ms_struct [on|off].
   void ActOnPragmaMSStruct(PragmaMSStructKind Kind);
 
   /// ActOnPragmaMSComment - Called on well formed
   /// \#pragma comment(kind, "arg").
-  void ActOnPragmaMSComment(PragmaMSCommentKind Kind, StringRef Arg);
+  void ActOnPragmaMSComment(SourceLocation CommentLoc, PragmaMSCommentKind Kind,
+                            StringRef Arg);
 
   /// ActOnPragmaMSPointersToMembers - called on well formed \#pragma
   /// pointers_to_members(representation method[, general purpose
   /// representation]).
   void ActOnPragmaMSPointersToMembers(
       LangOptions::PragmaMSPointersToMembersKind Kind,
       SourceLocation PragmaLoc);
 

include/clang/Serialization/ASTBitCodes.h

enum DeclCode {
       DECL_IMPORT,
       /// \brief An OMPThreadPrivateDecl record.
       DECL_OMP_THREADPRIVATE,
       /// \brief An EmptyDecl record.
       DECL_EMPTY,
       /// \brief An ObjCTypeParamDecl record.
       DECL_OBJC_TYPE_PARAM,
       /// \brief An OMPCapturedExprDecl record.
-      DECL_OMP_CAPTUREDEXPR
+      DECL_OMP_CAPTUREDEXPR,
+      /// \brief A PragmaCommentDecl record.
+      DECL_PRAGMA_COMMENT
     };
 
     /// \brief Record codes for each kind of statement or expression.
     ///
     /// These constants describe the records that describe statements
     /// or expressions. These records  occur within type and declarations
     /// block, so they begin with record values of 128.  Each constant 
     /// describes a record for a specific statement or expression class in the

lib/AST/ASTContext.cpp

if (VD->getStorageClass() == SC_Register)
       return false;
     if (VD->getDescribedVarTemplate() ||
         isa<VarTemplatePartialSpecializationDecl>(VD))
       return false;
   } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
     // We never need to emit an uninstantiated function template.
     if (FD->getTemplatedKind() == FunctionDecl::TK_FunctionTemplate)
       return false;
-  } else if (isa<OMPThreadPrivateDecl>(D))
+  } else if (isa<PragmaCommentDecl>(D))
+    return true;
+  else if (isa<OMPThreadPrivateDecl>(D))
     return true;
   else
     return false;
 
   // If this is a member of a class template, we do not need to emit it.
   if (D->getDeclContext()->isDependentContext())
     return false;
 

lib/AST/ASTDumper.cpp

public:
     void VisitRecordDecl(const RecordDecl *D);
     void VisitEnumConstantDecl(const EnumConstantDecl *D);
     void VisitIndirectFieldDecl(const IndirectFieldDecl *D);
     void VisitFunctionDecl(const FunctionDecl *D);
     void VisitFieldDecl(const FieldDecl *D);
     void VisitVarDecl(const VarDecl *D);
     void VisitFileScopeAsmDecl(const FileScopeAsmDecl *D);
     void VisitImportDecl(const ImportDecl *D);
+    void VisitPragmaCommentDecl(const PragmaCommentDecl *D);
 
     // C++ Decls
     void VisitNamespaceDecl(const NamespaceDecl *D);
     void VisitUsingDirectiveDecl(const UsingDirectiveDecl *D);
     void VisitNamespaceAliasDecl(const NamespaceAliasDecl *D);
     void VisitTypeAliasDecl(const TypeAliasDecl *D);
     void VisitTypeAliasTemplateDecl(const TypeAliasTemplateDecl *D);
     void VisitCXXRecordDecl(const CXXRecordDecl *D);

 void ASTDumper::VisitFileScopeAsmDecl(const FileScopeAsmDecl *D) {
   dumpStmt(D->getAsmString());
 }
 
 void ASTDumper::VisitImportDecl(const ImportDecl *D) {
   OS << ' ' << D->getImportedModule()->getFullModuleName();
 }
 
+void ASTDumper::VisitPragmaCommentDecl(const PragmaCommentDecl *D) {
+  OS << ' ';
+  switch (D->getCommentKind()) {
+  case PCK_Unknown:  llvm_unreachable("unexpected pragma comment kind");
+  case PCK_Compiler: OS << "compiler"; break;
+  case PCK_ExeStr:   OS << "exestr"; break;
+  case PCK_Lib:      OS << "lib"; break;
+  case PCK_Linker:   OS << "linker"; break;
+  case PCK_User:     OS << "user"; break;
+  }
+  StringRef Arg = D->getArg();
+  if (!Arg.empty())
+    OS << " \"" << Arg << "\"";
+}
+
 //===----------------------------------------------------------------------===//
 // C++ Declarations
 //===----------------------------------------------------------------------===//
 
 void ASTDumper::VisitNamespaceDecl(const NamespaceDecl *D) {
   dumpName(D);
   if (D->isInline())
     OS << " inline";

lib/AST/Decl.cpp

 //===----------------------------------------------------------------------===//
 
 void TranslationUnitDecl::anchor() { }
 
 TranslationUnitDecl *TranslationUnitDecl::Create(ASTContext &C) {
   return new (C, (DeclContext *)nullptr) TranslationUnitDecl(C);
 }
 
+void PragmaCommentDecl::anchor() { }
+
+PragmaCommentDecl *PragmaCommentDecl::Create(const ASTContext &C,
+                                             TranslationUnitDecl *DC,
+                                             SourceLocation CommentLoc,
+                                             PragmaMSCommentKind CommentKind,
+                                             StringRef Arg) {
+  PragmaCommentDecl *PCD =
+      new (C, DC, additionalSizeToAlloc<char>(Arg.size() + 1))
+          PragmaCommentDecl(DC, CommentLoc, CommentKind);
+  memcpy(PCD->getTrailingObjects<char>(), Arg.data(), Arg.size());
+  PCD->getTrailingObjects<char>()[Arg.size()] = '\0';
+  return PCD;
+}
+
+PragmaCommentDecl *PragmaCommentDecl::CreateDeserialized(ASTContext &C,
+                                                         unsigned ID,
+                                                         unsigned ArgSize) {
+  return new (C, ID, additionalSizeToAlloc<char>(ArgSize + 1))
+      PragmaCommentDecl(nullptr, SourceLocation(), PCK_Unknown);
+}
+
+
 void ExternCContextDecl::anchor() { }
 
 ExternCContextDecl *ExternCContextDecl::Create(const ASTContext &C,
                                                TranslationUnitDecl *DC) {
   return new (C, DC) ExternCContextDecl(DC);
 }
 
 void LabelDecl::anchor() { }

lib/AST/DeclBase.cpp

switch (DeclKind) {
     // Never have names.
     case Friend:
     case FriendTemplate:
     case AccessSpec:
     case LinkageSpec:
     case FileScopeAsm:
     case StaticAssert:
     case ObjCPropertyImpl:
+    case PragmaComment:
     case Block:
     case Captured:
     case TranslationUnit:
     case ExternCContext:
 
     case UsingDirective:
     case BuiltinTemplate:
     case ClassTemplateSpecialization:

lib/CodeGen/CGDecl.cpp

void CodeGenFunction::EmitDecl(const Decl &D) {
   case Decl::ObjCMethod:
   case Decl::ObjCCategory:
   case Decl::ObjCProtocol:
   case Decl::ObjCInterface:
   case Decl::ObjCCategoryImpl:
   case Decl::ObjCImplementation:
   case Decl::ObjCProperty:
   case Decl::ObjCCompatibleAlias:
+  case Decl::PragmaComment:
   case Decl::AccessSpec:
   case Decl::LinkageSpec:
   case Decl::ObjCPropertyImpl:
   case Decl::FileScopeAsm:
   case Decl::Friend:
   case Decl::FriendTemplate:
   case Decl::Block:
   case Decl::Captured:

lib/CodeGen/CodeGenAction.cpp

public:
     void AssignInheritanceModel(CXXRecordDecl *RD) override {
       Gen->AssignInheritanceModel(RD);
     }
 
     void HandleVTable(CXXRecordDecl *RD) override {
       Gen->HandleVTable(RD);
     }
 
-    void HandleLinkerOption(llvm::StringRef Opts) override {
-      Gen->HandleLinkerOption(Opts);
-    }
-
     void HandleDetectMismatch(llvm::StringRef Name,
                                       llvm::StringRef Value) override {
       Gen->HandleDetectMismatch(Name, Value);
     }
 
-    void HandleDependentLibrary(llvm::StringRef Opts) override {
-      Gen->HandleDependentLibrary(Opts);
-    }
-
     static void InlineAsmDiagHandler(const llvm::SMDiagnostic &SM,void *Context,
                                      unsigned LocCookie) {
       SourceLocation Loc = SourceLocation::getFromRawEncoding(LocCookie);
       ((BackendConsumer*)Context)->InlineAsmDiagHandler2(SM, Loc);
     }
 
     static void DiagnosticHandler(const llvm::DiagnosticInfo &DI,
                                   void *Context) {

lib/CodeGen/CodeGenModule.cpp

case Decl::ObjCMethod: {
     if (OMD->getBody())
       CodeGenFunction(*this).GenerateObjCMethod(OMD);
     break;
   }
   case Decl::ObjCCompatibleAlias:
     ObjCRuntime->RegisterAlias(cast<ObjCCompatibleAliasDecl>(D));
     break;
 
+  case Decl::PragmaComment: {
+    const auto *PCD = cast<PragmaCommentDecl>(D);
+    switch (PCD->getCommentKind()) {
+    case PCK_Unknown:
+      llvm_unreachable("unexpected pragma comment kind");
+    case PCK_Linker:
+      AppendLinkerOptions(PCD->getArg());
+      break;
+    case PCK_Lib:
+      AddDependentLib(PCD->getArg());
+      break;
+    case PCK_Compiler:
+    case PCK_ExeStr:
+    case PCK_User:
+      break; // We ignore all of these.
+    }
+    break;
+  }
+
   case Decl::LinkageSpec:
     EmitLinkageSpec(cast<LinkageSpecDecl>(D));
     break;
 
   case Decl::FileScopeAsm: {
     // File-scope asm is ignored during device-side CUDA compilation.
     if (LangOpts.CUDA && LangOpts.CUDAIsDevice)
       break;

lib/CodeGen/ModuleBuilder.cpp

void Initialize(ASTContext &Context) override {
 
       M->setTargetTriple(Ctx->getTargetInfo().getTriple().getTriple());
       M->setDataLayout(Ctx->getTargetInfo().getDataLayoutString());
       Builder.reset(new CodeGen::CodeGenModule(Context, HeaderSearchOpts,
                                                PreprocessorOpts, CodeGenOpts,
                                                *M, Diags, CoverageInfo));
 
       for (auto &&Lib : CodeGenOpts.DependentLibraries)
-        HandleDependentLibrary(Lib);
+        Builder->AddDependentLib(Lib);
       for (auto &&Opt : CodeGenOpts.LinkerOptions)
-        HandleLinkerOption(Opt);
+        Builder->AppendLinkerOptions(Opt);
     }
 
     void HandleCXXStaticMemberVarInstantiation(VarDecl *VD) override {
       if (Diags.hasErrorOccurred())
         return;
 
       Builder->HandleCXXStaticMemberVarInstantiation(VD);
     }
public:
 
     void HandleVTable(CXXRecordDecl *RD) override {
       if (Diags.hasErrorOccurred())
         return;
 
       Builder->EmitVTable(RD);
     }
 
-    void HandleLinkerOption(llvm::StringRef Opts) override {
-      Builder->AppendLinkerOptions(Opts);
-    }
-
     void HandleDetectMismatch(llvm::StringRef Name,
                               llvm::StringRef Value) override {
       Builder->AddDetectMismatch(Name, Value);
     }
-
-    void HandleDependentLibrary(llvm::StringRef Lib) override {
-      Builder->AddDependentLib(Lib);
-    }
   };
 }
 
 void CodeGenerator::anchor() { }
 
 CodeGenerator *clang::CreateLLVMCodeGen(
     DiagnosticsEngine &Diags, const std::string &ModuleName,
     const HeaderSearchOptions &HeaderSearchOpts,
     const PreprocessorOptions &PreprocessorOpts, const CodeGenOptions &CGO,
     llvm::LLVMContext &C, CoverageSourceInfo *CoverageInfo) {
   return new CodeGeneratorImpl(Diags, ModuleName, HeaderSearchOpts,
                                PreprocessorOpts, CGO, C, CoverageInfo);
 }

lib/Frontend/MultiplexConsumer.cpp

for (auto &Consumer : Consumers)
     Consumer->HandleTopLevelDeclInObjCContainer(D);
 }
 
 void MultiplexConsumer::HandleImplicitImportDecl(ImportDecl *D) {
   for (auto &Consumer : Consumers)
     Consumer->HandleImplicitImportDecl(D);
 }
 
-void MultiplexConsumer::HandleLinkerOption(llvm::StringRef Opts) {
-  for (auto &Consumer : Consumers)
-    Consumer->HandleLinkerOption(Opts);
-}
-
 void MultiplexConsumer::HandleDetectMismatch(llvm::StringRef Name, llvm::StringRef Value) {
   for (auto &Consumer : Consumers)
     Consumer->HandleDetectMismatch(Name, Value);
 }
 
-void MultiplexConsumer::HandleDependentLibrary(llvm::StringRef Lib) {
-  for (auto &Consumer : Consumers)
-    Consumer->HandleDependentLibrary(Lib);
-}
-
 void MultiplexConsumer::CompleteTentativeDefinition(VarDecl *D) {
   for (auto &Consumer : Consumers)
     Consumer->CompleteTentativeDefinition(D);
 }
 
 void MultiplexConsumer::AssignInheritanceModel(CXXRecordDecl *RD) {
   for (auto &Consumer : Consumers)
     Consumer->AssignInheritanceModel(RD);

lib/Parse/ParsePragma.cpp

 //===--- ParsePragma.cpp - Language specific pragma parsing ---------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements the language specific #pragma handlers.
 //
 //===----------------------------------------------------------------------===//
 
 #include "RAIIObjectsForParser.h"
 #include "clang/AST/ASTContext.h"
+#include "clang/Basic/PragmaKinds.h"
 #include "clang/Basic/TargetInfo.h"
 #include "clang/Lex/Preprocessor.h"
 #include "clang/Parse/ParseDiagnostic.h"
 #include "clang/Parse/Parser.h"
 #include "clang/Sema/LoopHint.h"
 #include "clang/Sema/Scope.h"
 #include "llvm/ADT/StringSwitch.h"
 using namespace clang;
void PragmaCommentHandler::HandlePragma(Preprocessor &PP,
   PP.Lex(Tok);
   if (Tok.isNot(tok::identifier)) {
     PP.Diag(CommentLoc, diag::err_pragma_comment_malformed);
     return;
   }
 
   // Verify that this is one of the 5 whitelisted options.
   IdentifierInfo *II = Tok.getIdentifierInfo();
-  Sema::PragmaMSCommentKind Kind =
-    llvm::StringSwitch<Sema::PragmaMSCommentKind>(II->getName())
-    .Case("linker",   Sema::PCK_Linker)
-    .Case("lib",      Sema::PCK_Lib)
-    .Case("compiler", Sema::PCK_Compiler)
-    .Case("exestr",   Sema::PCK_ExeStr)
-    .Case("user",     Sema::PCK_User)
-    .Default(Sema::PCK_Unknown);
-  if (Kind == Sema::PCK_Unknown) {
+  PragmaMSCommentKind Kind =
+    llvm::StringSwitch<PragmaMSCommentKind>(II->getName())
+    .Case("linker",   PCK_Linker)
+    .Case("lib",      PCK_Lib)
+    .Case("compiler", PCK_Compiler)
+    .Case("exestr",   PCK_ExeStr)
+    .Case("user",     PCK_User)
+    .Default(PCK_Unknown);
+  if (Kind == PCK_Unknown) {
     PP.Diag(Tok.getLocation(), diag::err_pragma_comment_unknown_kind);
     return;
   }
 
   // On PS4, issue a warning about any pragma comments other than
   // #pragma comment lib.
-  if (PP.getTargetInfo().getTriple().isPS4() && Kind != Sema::PCK_Lib) {
+  if (PP.getTargetInfo().getTriple().isPS4() && Kind != PCK_Lib) {
     PP.Diag(Tok.getLocation(), diag::warn_pragma_comment_ignored)
       << II->getName();
     return;
   }
 
   // Read the optional string if present.
   PP.Lex(Tok);
   std::string ArgumentString;
if (Tok.isNot(tok::eod)) {
     PP.Diag(Tok.getLocation(), diag::err_pragma_comment_malformed);
     return;
   }
 
   // If the pragma is lexically sound, notify any interested PPCallbacks.
   if (PP.getPPCallbacks())
     PP.getPPCallbacks()->PragmaComment(CommentLoc, II, ArgumentString);
 
-  Actions.ActOnPragmaMSComment(Kind, ArgumentString);
+  Actions.ActOnPragmaMSComment(CommentLoc, Kind, ArgumentString);
 }
 
 // #pragma clang optimize off
 // #pragma clang optimize on
 void PragmaOptimizeHandler::HandlePragma(Preprocessor &PP, 
                                         PragmaIntroducerKind Introducer,
                                         Token &FirstToken) {
   Token Tok;

lib/Sema/SemaAttr.cpp

case Sema::PPK_Pop: // pack(pop [, id] [,  n])
     break;
   }
 }
 
 void Sema::ActOnPragmaMSStruct(PragmaMSStructKind Kind) { 
   MSStructPragmaOn = (Kind == PMSST_ON);
 }
 
-void Sema::ActOnPragmaMSComment(PragmaMSCommentKind Kind, StringRef Arg) {
-  // FIXME: Serialize this.
-  switch (Kind) {
-  case PCK_Unknown:
-    llvm_unreachable("unexpected pragma comment kind");
-  case PCK_Linker:
-    Consumer.HandleLinkerOption(Arg);
-    return;
-  case PCK_Lib:
-    Consumer.HandleDependentLibrary(Arg);
-    return;
-  case PCK_Compiler:
-  case PCK_ExeStr:
-  case PCK_User:
-    return;  // We ignore all of these.
-  }
-  llvm_unreachable("invalid pragma comment kind");
+void Sema::ActOnPragmaMSComment(SourceLocation CommentLoc,
+                                PragmaMSCommentKind Kind, StringRef Arg) {
+  auto *PCD = PragmaCommentDecl::Create(
+      Context, Context.getTranslationUnitDecl(), CommentLoc, Kind, Arg);
+  Context.getTranslationUnitDecl()->addDecl(PCD);
+  Consumer.HandleTopLevelDecl(DeclGroupRef(PCD));
 }
 
 void Sema::ActOnPragmaDetectMismatch(StringRef Name, StringRef Value) {
   // FIXME: Serialize this.
   Consumer.HandleDetectMismatch(Name, Value);
 }
 
 void Sema::ActOnPragmaMSPointersToMembers(

lib/Sema/SemaTemplateInstantiateDecl.cpp

 }
 
 Decl *
 TemplateDeclInstantiator::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
   llvm_unreachable("Translation units cannot be instantiated");
 }
 
 Decl *
+TemplateDeclInstantiator::VisitPragmaCommentDecl(PragmaCommentDecl *D) {
+  llvm_unreachable("pragma comment cannot be instantiated");
+}
+
+Decl *
 TemplateDeclInstantiator::VisitExternCContextDecl(ExternCContextDecl *D) {
   llvm_unreachable("extern \"C\" context cannot be instantiated");
 }
 
 Decl *
 TemplateDeclInstantiator::VisitLabelDecl(LabelDecl *D) {
   LabelDecl *Inst = LabelDecl::Create(SemaRef.Context, Owner, D->getLocation(),
                                       D->getIdentifier());

lib/Serialization/ASTCommon.cpp

bool serialization::isRedeclarableDeclKind(unsigned Kind) {
   case Decl::ObjCMethod:
   case Decl::ObjCCategory:
   case Decl::ObjCCategoryImpl:
   case Decl::ObjCImplementation:
   case Decl::ObjCProperty:
   case Decl::ObjCCompatibleAlias:
   case Decl::LinkageSpec:
   case Decl::ObjCPropertyImpl:
+  case Decl::PragmaComment:
   case Decl::FileScopeAsm:
   case Decl::AccessSpec:
   case Decl::Friend:
   case Decl::FriendTemplate:
   case Decl::StaticAssert:
   case Decl::Block:
   case Decl::Captured:
   case Decl::ClassScopeFunctionSpecialization:

lib/Serialization/ASTReaderDecl.cpp

class ASTDeclReader : public DeclVisitor<ASTDeclReader, void> {
     TypeSourceInfo *GetTypeSourceInfo(const RecordData &R, unsigned &I) {
       return Reader.GetTypeSourceInfo(F, R, I);
     }
 
     serialization::DeclID ReadDeclID(const RecordData &R, unsigned &I) {
       return Reader.ReadDeclID(F, R, I);
     }
 
+    std::string ReadString(const RecordData &R, unsigned &I) {
+      return Reader.ReadString(R, I);
+    }
+
     void ReadDeclIDList(SmallVectorImpl<DeclID> &IDs) {
       for (unsigned I = 0, Size = Record[Idx++]; I != Size; ++I)
         IDs.push_back(ReadDeclID(Record, Idx));
     }
 
     Decl *ReadDecl(const RecordData &R, unsigned &I) {
       return Reader.ReadDecl(F, R, I);
     }
void UpdateDecl(Decl *D, ModuleFile &ModuleFile,
                     const RecordData &Record);
 
     static void setNextObjCCategory(ObjCCategoryDecl *Cat,
                                     ObjCCategoryDecl *Next) {
       Cat->NextClassCategory = Next;
     }
 
     void VisitDecl(Decl *D);
+    void VisitPragmaCommentDecl(PragmaCommentDecl *D);
     void VisitTranslationUnitDecl(TranslationUnitDecl *TU);
     void VisitNamedDecl(NamedDecl *ND);
     void VisitLabelDecl(LabelDecl *LD);
     void VisitNamespaceDecl(NamespaceDecl *D);
     void VisitUsingDirectiveDecl(UsingDirectiveDecl *D);
     void VisitNamespaceAliasDecl(NamespaceAliasDecl *D);
     void VisitTypeDecl(TypeDecl *TD);
     RedeclarableResult VisitTypedefNameDecl(TypedefNameDecl *TD);
if (D->Hidden) {
         // Note that this declaration was hidden because its owning module is 
         // not yet visible.
         Reader.HiddenNamesMap[Owner].push_back(D);
       }
     }
   }
 }
 
+void ASTDeclReader::VisitPragmaCommentDecl(PragmaCommentDecl *D) {
+  VisitDecl(D);
+  D->setLocation(ReadSourceLocation(Record, Idx));
+  D->CommentKind = (PragmaMSCommentKind)Record[Idx++];
+  std::string Arg = ReadString(Record, Idx);
+  memcpy(D->getTrailingObjects<char>(), Arg.data(), Arg.size());
+  D->getTrailingObjects<char>()[Arg.size()] = '\0';
+}
+
 void ASTDeclReader::VisitTranslationUnitDecl(TranslationUnitDecl *TU) {
   llvm_unreachable("Translation units are not serialized");
 }
 
 void ASTDeclReader::VisitNamedDecl(NamedDecl *ND) {
   VisitDecl(ND);
   ND->setDeclName(Reader.ReadDeclarationName(F, Record, Idx));
   AnonymousDeclNumber = Record[Idx++];

 static bool isConsumerInterestedIn(Decl *D, bool HasBody) {
   // An ObjCMethodDecl is never considered as "interesting" because its
   // implementation container always is.
 
   if (isa<FileScopeAsmDecl>(D) || 
       isa<ObjCProtocolDecl>(D) || 
       isa<ObjCImplDecl>(D) ||
       isa<ImportDecl>(D) ||
+      isa<PragmaCommentDecl>(D) ||
       isa<OMPThreadPrivateDecl>(D))
     return true;
   if (VarDecl *Var = dyn_cast<VarDecl>(D))
     return Var->isFileVarDecl() &&
            Var->isThisDeclarationADefinition() == VarDecl::Definition;
   if (FunctionDecl *Func = dyn_cast<FunctionDecl>(D))
     return Func->doesThisDeclarationHaveABody() || HasBody;
   
case DECL_IMPORT:
     D = ImportDecl::CreateDeserialized(Context, ID, Record.back());
     break;
   case DECL_OMP_THREADPRIVATE:
     D = OMPThreadPrivateDecl::CreateDeserialized(Context, ID, Record[Idx++]);
     break;
   case DECL_OMP_CAPTUREDEXPR:
     D = OMPCapturedExprDecl::CreateDeserialized(Context, ID);
     break;
+  case DECL_PRAGMA_COMMENT:
+    D = PragmaCommentDecl::CreateDeserialized(Context, ID, Record[Idx++]);
+    break;
   case DECL_EMPTY:
     D = EmptyDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_OBJC_TYPE_PARAM:
     D = ObjCTypeParamDecl::CreateDeserialized(Context, ID);
     break;
   }
 

lib/Serialization/ASTWriterDecl.cpp

public:
 
     ASTDeclWriter(ASTWriter &Writer, ASTContext &Context, RecordData &Record)
       : Writer(Writer), Context(Context), Record(Record) {
     }
 
     void Visit(Decl *D);
 
     void VisitDecl(Decl *D);
+    void VisitPragmaCommentDecl(PragmaCommentDecl *D);
     void VisitTranslationUnitDecl(TranslationUnitDecl *D);
     void VisitNamedDecl(NamedDecl *D);
     void VisitLabelDecl(LabelDecl *LD);
     void VisitNamespaceDecl(NamespaceDecl *D);
     void VisitUsingDirectiveDecl(UsingDirectiveDecl *D);
     void VisitNamespaceAliasDecl(NamespaceAliasDecl *D);
     void VisitTypeDecl(TypeDecl *D);
     void VisitTypedefNameDecl(TypedefNameDecl *D);
while (auto *NS = dyn_cast<NamespaceDecl>(DC->getRedeclContext())) {
       Writer.UpdatedDeclContexts.insert(NS->getPrimaryContext());
       if (!NS->isInlineNamespace())
         break;
       DC = NS->getParent();
     }
   }
 }
 
+void ASTDeclWriter::VisitPragmaCommentDecl(PragmaCommentDecl *D) {
+  StringRef Arg = D->getArg();
+  Record.push_back(Arg.size());
+  VisitDecl(D);
+  Writer.AddSourceLocation(D->getLocStart(), Record);
+  Record.push_back(D->getCommentKind());
+  Writer.AddString(Arg, Record);
+  Code = serialization::DECL_PRAGMA_COMMENT;
+}
+
 void ASTDeclWriter::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
   llvm_unreachable("Translation units aren't directly serialized");
 }
 
 void ASTDeclWriter::VisitNamedDecl(NamedDecl *D) {
   VisitDecl(D);
   Writer.AddDeclarationName(D->getDeclName(), Record);
   Record.push_back(needsAnonymousDeclarationNumber(D)

test/PCH/pragma-comment.c

+// Test this without pch.
+// RUN: %clang_cc1 %s -Wunknown-pragmas -Werror -triple x86_64-pc-win32 -fms-extensions -emit-llvm -include %s -o - | FileCheck %s
+
+// Test with pch.
+// RUN: %clang_cc1 %s -Wunknown-pragmas -Werror -triple x86_64-pc-win32 -fms-extensions -emit-pch -o %t
+// RUN: %clang_cc1 %s -Wunknown-pragmas -Werror -triple x86_64-pc-win32 -fms-extensions -emit-llvm -include-pch %t -o - | FileCheck %s
+
+// The first run line creates a pch, and since at that point HEADER is not
+// defined, the only thing contained in the pch is the pragma. The second line
+// then includes that pch, so HEADER is defined and the actual code is compiled.
+// The check then makes sure that the pragma is in effect in the file that
+// includes the pch.
+
+// expected-no-diagnostics
+
+#ifndef HEADER
+#define HEADER
+#pragma comment(lib, "foo.lib")
+
+#else
+
+// CHECK: "/DEFAULTLIB:foo.lib"
+
+#endif

tools/libclang/CIndex.cpp

CXCursor clang_getCursorDefinition(CXCursor C) {
   case Decl::Captured:
   case Decl::OMPCapturedExpr:
   case Decl::Label:  // FIXME: Is this right??
   case Decl::ClassScopeFunctionSpecialization:
   case Decl::Import:
   case Decl::OMPThreadPrivate:
   case Decl::ObjCTypeParam:
   case Decl::BuiltinTemplate:
+  case Decl::PragmaComment:
     return C;
 
   // Declaration kinds that don't make any sense here, but are
   // nonetheless harmless.
   case Decl::Empty:
   case Decl::TranslationUnit:
   case Decl::ExternCContext:
     break;