Beispiel #1
0
static void setThunkVisibility(CodeGenModule &CGM, const CXXMethodDecl *MD,
                               const ThunkInfo &Thunk, llvm::Function *Fn) {
  CGM.setGlobalVisibility(Fn, MD);

  if (!CGM.getCodeGenOpts().HiddenWeakVTables)
    return;

  // If the thunk has weak/linkonce linkage, but the function must be
  // emitted in every translation unit that references it, then we can
  // emit its thunks with hidden visibility, since its thunks must be
  // emitted when the function is.

  // This follows CodeGenModule::setTypeVisibility; see the comments
  // there for explanation.

  if ((Fn->getLinkage() != llvm::GlobalVariable::LinkOnceODRLinkage &&
       Fn->getLinkage() != llvm::GlobalVariable::WeakODRLinkage) ||
      Fn->getVisibility() != llvm::GlobalVariable::DefaultVisibility)
    return;

  if (MD->getExplicitVisibility())
    return;

  switch (MD->getTemplateSpecializationKind()) {
  case TSK_ExplicitInstantiationDefinition:
  case TSK_ExplicitInstantiationDeclaration:
    return;

  case TSK_Undeclared:
    break;

  case TSK_ExplicitSpecialization:
  case TSK_ImplicitInstantiation:
    if (!CGM.getCodeGenOpts().HiddenWeakTemplateVTables)
      return;
    break;
  }

  // If there's an explicit definition, and that definition is
  // out-of-line, then we can't assume that all users will have a
  // definition to emit.
  const FunctionDecl *Def = 0;
  if (MD->hasBody(Def) && Def->isOutOfLine())
    return;

  Fn->setVisibility(llvm::GlobalValue::HiddenVisibility);
}
Beispiel #2
0
CodeGenTypes::CodeGenTypes(CodeGenModule &CGM)
  : Context(CGM.getContext()), Target(Context.getTargetInfo()),
    TheModule(CGM.getModule()), TheTargetData(CGM.getTargetData()),
    TheABIInfo(CGM.getTargetCodeGenInfo().getABIInfo()),
    TheCXXABI(CGM.getCXXABI()),
    CodeGenOpts(CGM.getCodeGenOpts()), CGM(CGM) {
  SkippedLayout = false;
}
CodeGenTypes::CodeGenTypes(CodeGenModule &cgm)
  : CGM(cgm), Context(cgm.getContext()), TheModule(cgm.getModule()),
    TheDataLayout(cgm.getDataLayout()),
    Target(cgm.getTarget()), TheCXXABI(cgm.getCXXABI()),
    CodeGenOpts(cgm.getCodeGenOpts()),
    TheABIInfo(cgm.getTargetCodeGenInfo().getABIInfo()) {
  SkippedLayout = false;
}
Beispiel #4
0
/// Given that we're currently at the end of the translation unit, and
/// we've emitted a reference to the v-table for this class, should
/// we define that v-table?
static bool shouldEmitVTableAtEndOfTranslationUnit(CodeGenModule &CGM,
                                                   const CXXRecordDecl *RD) {
  // If we're building with optimization, we always emit v-tables
  // since that allows for virtual function calls to be devirtualized.
  // If the v-table is defined strongly elsewhere, this definition
  // will be emitted available_externally.
  //
  // However, we don't want to do this in -fapple-kext mode, because
  // kext mode does not permit devirtualization.
  if (CGM.getCodeGenOpts().OptimizationLevel && !CGM.getLangOpts().AppleKext)
    return true;

  return !CGM.getVTables().isVTableExternal(RD);
}
Beispiel #5
0
static bool shouldEmitVTableThunk(CodeGenModule &CGM, const CXXMethodDecl *MD,
                                  bool IsUnprototyped, bool ForVTable) {
  // Always emit thunks in the MS C++ ABI. We cannot rely on other TUs to
  // provide thunks for us.
  if (CGM.getTarget().getCXXABI().isMicrosoft())
    return true;

  // In the Itanium C++ ABI, vtable thunks are provided by TUs that provide
  // definitions of the main method. Therefore, emitting thunks with the vtable
  // is purely an optimization. Emit the thunk if optimizations are enabled and
  // all of the parameter types are complete.
  if (ForVTable)
    return CGM.getCodeGenOpts().OptimizationLevel && !IsUnprototyped;

  // Always emit thunks along with the method definition.
  return true;
}
Beispiel #6
0
static bool shouldEmitAvailableExternallyVTable(const CodeGenModule &CGM,
                                                const CXXRecordDecl *RD) {
  return CGM.getCodeGenOpts().OptimizationLevel > 0 &&
         CGM.getCXXABI().canSpeculativelyEmitVTable(RD);
}