Reinstate r284008 reverted in r284081, with two fixes:

1) Merge and demote variable definitions when we find a redefinition in
MergeVarDecls, not only when we find one in AddInitializerToDecl (we only reach
the second case if it's the addition of the initializer itself that converts an
existing declaration into a definition).

2) When rebuilding a redeclaration chain for a variable, if we merge two
definitions together, mark the definitions as merged so the retained definition
is made visible whenever the demoted definition would have been.

Original commit message (from r283882):

[modules] PR28752: Do not instantiate variable declarations which are not visible.

Original patch by Vassil Vassilev! Changes listed above are mine.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@284284 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/AST/Decl.h b/include/clang/AST/Decl.h
index d24b37af61576b33df8d59fd36549665fc1430d6..6dd553ec6e9acdc786bf16708c27f45707870761 100644 (file)
--- a/include/clang/AST/Decl.h
+++ b/include/clang/AST/Decl.h
@@ -865,6 +865,11 @@ protected:
 
     unsigned : NumVarDeclBits;
 
+    // FIXME: We need something similar to CXXRecordDecl::DefinitionData.
+    /// \brief Whether this variable is a definition which was demoted due to
+    /// module merge.
+    unsigned IsThisDeclarationADemotedDefinition : 1;
+
     /// \brief Whether this variable is the exception variable in a C++ catch
     /// or an Objective-C @catch statement.
     unsigned ExceptionVar : 1;
@@ -1198,12 +1203,28 @@ public:
   InitializationStyle getInitStyle() const {
     return static_cast<InitializationStyle>(VarDeclBits.InitStyle);
   }
-
   /// \brief Whether the initializer is a direct-initializer (list or call).
   bool isDirectInit() const {
     return getInitStyle() != CInit;
   }
 
+  /// \brief If this definition should pretend to be a declaration.
+  bool isThisDeclarationADemotedDefinition() const {
+    return isa<ParmVarDecl>(this) ? false :
+      NonParmVarDeclBits.IsThisDeclarationADemotedDefinition;
+  }
+
+  /// \brief This is a definition which should be demoted to a declaration.
+  ///
+  /// In some cases (mostly module merging) we can end up with two visible
+  /// definitions one of which needs to be demoted to a declaration to keep
+  /// the AST invariants.
+  void demoteThisDefinitionToDeclaration() {
+    assert (isThisDeclarationADefinition() && "Not a definition!");
+    assert (!isa<ParmVarDecl>(this) && "Cannot demote ParmVarDecls!");
+    NonParmVarDeclBits.IsThisDeclarationADemotedDefinition = 1;
+  }
+
   /// \brief Determine whether this variable is the exception variable in a
   /// C++ catch statememt or an Objective-C \@catch statement.
   bool isExceptionVariable() const {
@@ -1302,6 +1323,10 @@ public:
     NonParmVarDeclBits.PreviousDeclInSameBlockScope = Same;
   }
 
+  /// \brief Retrieve the variable declaration from which this variable could
+  /// be instantiated, if it is an instantiation (rather than a non-template).
+  VarDecl *getTemplateInstantiationPattern() const;
+
   /// \brief If this variable is an instantiated static data member of a
   /// class template specialization, returns the templated static data member
   /// from which it was instantiated.

diff --git a/include/clang/Sema/Sema.h b/include/clang/Sema/Sema.h
index ba63555284bc50f5a23e371a4e8ef7d8e56fdb0c..a50dd66791e9f6967275c82dfb8c1103fb5e7cdb 100644 (file)
--- a/include/clang/Sema/Sema.h
+++ b/include/clang/Sema/Sema.h
@@ -2286,6 +2286,7 @@ public:
   void MergeVarDecl(VarDecl *New, LookupResult &Previous);
   void MergeVarDeclTypes(VarDecl *New, VarDecl *Old, bool MergeTypeWithOld);
   void MergeVarDeclExceptionSpecs(VarDecl *New, VarDecl *Old);
+  bool checkVarDeclRedefinition(VarDecl *OldDefn, VarDecl *NewDefn);
   bool MergeCXXFunctionDecl(FunctionDecl *New, FunctionDecl *Old, Scope *S);
 
   // AssignmentAction - This is used by all the assignment diagnostic functions

diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp
index 657d2e01dc73bbb28f8bebc11db6e6ffd340ebe6..235f2778e878e8a50599c5db1cd80bfd88737002 100644 (file)
--- a/lib/AST/Decl.cpp
+++ b/lib/AST/Decl.cpp
@@ -1926,6 +1926,9 @@ VarDecl::isThisDeclarationADefinition(ASTContext &C) const {
   //
   // FIXME: How do you declare (but not define) a partial specialization of
   // a static data member template outside the containing class?
+  if (isThisDeclarationADemotedDefinition())
+    return DeclarationOnly;
+
   if (isStaticDataMember()) {
     if (isOutOfLine() &&
         !(getCanonicalDecl()->isInline() &&
@@ -2250,6 +2253,56 @@ bool VarDecl::checkInitIsICE() const {
   return Eval->IsICE;
 }
 
+VarDecl *VarDecl::getTemplateInstantiationPattern() const {
+  // If it's a variable template specialization, find the template or partial
+  // specialization from which it was instantiated.
+  if (auto *VDTemplSpec = dyn_cast<VarTemplateSpecializationDecl>(this)) {
+    auto From = VDTemplSpec->getInstantiatedFrom();
+    if (auto *VTD = From.dyn_cast<VarTemplateDecl *>()) {
+      while (auto *NewVTD = VTD->getInstantiatedFromMemberTemplate()) {
+        if (NewVTD->isMemberSpecialization())
+          break;
+        VTD = NewVTD;
+      }
+      return VTD->getTemplatedDecl()->getDefinition();
+    }
+    if (auto *VTPSD =
+            From.dyn_cast<VarTemplatePartialSpecializationDecl *>()) {
+      while (auto *NewVTPSD = VTPSD->getInstantiatedFromMember()) {
+        if (NewVTPSD->isMemberSpecialization())
+          break;
+        VTPSD = NewVTPSD;
+      }
+      return VTPSD->getDefinition();
+    }
+  }
+
+  if (MemberSpecializationInfo *MSInfo = getMemberSpecializationInfo()) {
+    if (isTemplateInstantiation(MSInfo->getTemplateSpecializationKind())) {
+      VarDecl *VD = getInstantiatedFromStaticDataMember();
+      while (auto *NewVD = VD->getInstantiatedFromStaticDataMember())
+        VD = NewVD;
+      return VD->getDefinition();
+    }
+  }
+
+  if (VarTemplateDecl *VarTemplate = getDescribedVarTemplate()) {
+
+    while (VarTemplate->getInstantiatedFromMemberTemplate()) {
+      if (VarTemplate->isMemberSpecialization())
+        break;
+      VarTemplate = VarTemplate->getInstantiatedFromMemberTemplate();
+    }
+
+    assert((!VarTemplate->getTemplatedDecl() ||
+            !isTemplateInstantiation(getTemplateSpecializationKind())) &&
+           "couldn't find pattern for variable instantiation");
+
+    return VarTemplate->getTemplatedDecl();
+  }
+  return nullptr;
+}
+
 VarDecl *VarDecl::getInstantiatedFromStaticDataMember() const {
   if (MemberSpecializationInfo *MSI = getMemberSpecializationInfo())
     return cast<VarDecl>(MSI->getInstantiatedFrom());

diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 4536fe8df8a749d2db997fe82c840cb4ac869503..efdf8a3226f221bacd6a8eab5cdc0fbfafec36a6 100644 (file)
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -3675,29 +3675,16 @@ void Sema::MergeVarDecl(VarDecl *New, LookupResult &Previous) {
   }
 
   // C++ doesn't have tentative definitions, so go right ahead and check here.
-  VarDecl *Def;
   if (getLangOpts().CPlusPlus &&
-      New->isThisDeclarationADefinition() == VarDecl::Definition &&
-      (Def = Old->getDefinition())) {
-    NamedDecl *Hidden = nullptr;
-    if (!hasVisibleDefinition(Def, &Hidden) &&
-        (New->getFormalLinkage() == InternalLinkage ||
-         New->getDescribedVarTemplate() ||
-         New->getNumTemplateParameterLists() ||
-         New->getDeclContext()->isDependentContext())) {
-      // The previous definition is hidden, and multiple definitions are
-      // permitted (in separate TUs). Form another definition of it.
-    } else if (Old->isStaticDataMember() &&
-               Old->getCanonicalDecl()->isInline() &&
-               Old->getCanonicalDecl()->isConstexpr()) {
+      New->isThisDeclarationADefinition() == VarDecl::Definition) {
+    if (Old->isStaticDataMember() && Old->getCanonicalDecl()->isInline() &&
+        Old->getCanonicalDecl()->isConstexpr()) {
       // This definition won't be a definition any more once it's been merged.
       Diag(New->getLocation(),
            diag::warn_deprecated_redundant_constexpr_static_def);
-    } else {
-      Diag(New->getLocation(), diag::err_redefinition) << New;
-      Diag(Def->getLocation(), diag::note_previous_definition);
-      New->setInvalidDecl();
-      return;
+    } else if (VarDecl *Def = Old->getDefinition()) {
+      if (checkVarDeclRedefinition(Def, New))
+        return;
     }
   }
 
@@ -3726,6 +3713,32 @@ void Sema::MergeVarDecl(VarDecl *New, LookupResult &Previous) {
     New->setImplicitlyInline();
 }
 
+/// We've just determined that \p Old and \p New both appear to be definitions
+/// of the same variable. Either diagnose or fix the problem.
+bool Sema::checkVarDeclRedefinition(VarDecl *Old, VarDecl *New) {
+  if (!hasVisibleDefinition(Old) &&
+      (New->getFormalLinkage() == InternalLinkage ||
+       New->isInline() ||
+       New->getDescribedVarTemplate() ||
+       New->getNumTemplateParameterLists() ||
+       New->getDeclContext()->isDependentContext())) {
+    // The previous definition is hidden, and multiple definitions are
+    // permitted (in separate TUs). Demote this to a declaration.
+    New->demoteThisDefinitionToDeclaration();
+
+    // Make the canonical definition visible.
+    if (auto *OldTD = Old->getDescribedVarTemplate())
+      makeMergedDefinitionVisible(OldTD, New->getLocation());
+    makeMergedDefinitionVisible(Old, New->getLocation());
+    return false;
+  } else {
+    Diag(New->getLocation(), diag::err_redefinition) << New;
+    Diag(Old->getLocation(), diag::note_previous_definition);
+    New->setInvalidDecl();
+    return true;
+  }
+}
+
 /// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with
 /// no declarator (e.g. "struct foo;") is parsed.
 Decl *
@@ -9697,25 +9710,15 @@ void Sema::AddInitializerToDecl(Decl *RealDecl, Expr *Init,
       VDecl->setInvalidDecl();
   }
 
+  // If adding the initializer will turn this declaration into a definition,
+  // and we already have a definition for this variable, diagnose or otherwise
+  // handle the situation.
   VarDecl *Def;
   if ((Def = VDecl->getDefinition()) && Def != VDecl &&
-      (!VDecl->isStaticDataMember() || VDecl->isOutOfLine())) {
-    NamedDecl *Hidden = nullptr;
-    if (!hasVisibleDefinition(Def, &Hidden) &&
-        (VDecl->getFormalLinkage() == InternalLinkage ||
-         VDecl->getDescribedVarTemplate() ||
-         VDecl->getNumTemplateParameterLists() ||
-         VDecl->getDeclContext()->isDependentContext())) {
-      // The previous definition is hidden, and multiple definitions are
-      // permitted (in separate TUs). Form another definition of it.
-    } else {
-      Diag(VDecl->getLocation(), diag::err_redefinition)
-        << VDecl->getDeclName();
-      Diag(Def->getLocation(), diag::note_previous_definition);
-      VDecl->setInvalidDecl();
-      return;
-    }
-  }
+      (!VDecl->isStaticDataMember() || VDecl->isOutOfLine()) &&
+      !VDecl->isThisDeclarationADemotedDefinition() &&
+      checkVarDeclRedefinition(Def, VDecl))
+    return;
 
   if (getLangOpts().CPlusPlus) {
     // C++ [class.static.data]p4

diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
index 0a03f8efc1483dcf52da9da3de6884e9c9f1c9e5..71b2153d05a019f407b59e57c1e5aae916de61c3 100644 (file)
--- a/lib/Sema/SemaTemplate.cpp
+++ b/lib/Sema/SemaTemplate.cpp
@@ -466,10 +466,14 @@ bool Sema::DiagnoseUninstantiableTemplate(SourceLocation PointOfInstantiation,
                                           const NamedDecl *PatternDef,
                                           TemplateSpecializationKind TSK,
                                           bool Complain /*= true*/) {
-  assert(isa<TagDecl>(Instantiation) || isa<FunctionDecl>(Instantiation));
+  assert(isa<TagDecl>(Instantiation) || isa<FunctionDecl>(Instantiation) ||
+         isa<VarDecl>(Instantiation));
 
-  if (PatternDef && (isa<FunctionDecl>(PatternDef)
-                     || !cast<TagDecl>(PatternDef)->isBeingDefined())) {
+  bool IsEntityBeingDefined = false;
+  if (const TagDecl *TD = dyn_cast_or_null<TagDecl>(PatternDef))
+    IsEntityBeingDefined = TD->isBeingDefined();
+
+  if (PatternDef && !IsEntityBeingDefined) {
     NamedDecl *SuggestedDef = nullptr;
     if (!hasVisibleDefinition(const_cast<NamedDecl*>(PatternDef), &SuggestedDef,
                               /*OnlyNeedComplete*/false)) {
@@ -486,13 +490,14 @@ bool Sema::DiagnoseUninstantiableTemplate(SourceLocation PointOfInstantiation,
   if (!Complain || (PatternDef && PatternDef->isInvalidDecl()))
     return true;
 
+  llvm::Optional<unsigned> Note;
   QualType InstantiationTy;
   if (TagDecl *TD = dyn_cast<TagDecl>(Instantiation))
     InstantiationTy = Context.getTypeDeclType(TD);
   if (PatternDef) {
     Diag(PointOfInstantiation,
          diag::err_template_instantiate_within_definition)
-      << (TSK != TSK_ImplicitInstantiation)
+      << /*implicit|explicit*/(TSK != TSK_ImplicitInstantiation)
       << InstantiationTy;
     // Not much point in noting the template declaration here, since
     // we're lexically inside it.
@@ -501,28 +506,44 @@ bool Sema::DiagnoseUninstantiableTemplate(SourceLocation PointOfInstantiation,
     if (isa<FunctionDecl>(Instantiation)) {
       Diag(PointOfInstantiation,
            diag::err_explicit_instantiation_undefined_member)
-        << 1 << Instantiation->getDeclName() << Instantiation->getDeclContext();
+        << /*member function*/ 1 << Instantiation->getDeclName()
+        << Instantiation->getDeclContext();
+      Note = diag::note_explicit_instantiation_here;
     } else {
+      assert(isa<TagDecl>(Instantiation) && "Must be a TagDecl!");
       Diag(PointOfInstantiation,
            diag::err_implicit_instantiate_member_undefined)
         << InstantiationTy;
+      Note = diag::note_member_declared_at;
     }
-    Diag(Pattern->getLocation(), isa<FunctionDecl>(Instantiation)
-                                     ? diag::note_explicit_instantiation_here
-                                     : diag::note_member_declared_at);
   } else {
-    if (isa<FunctionDecl>(Instantiation))
+    if (isa<FunctionDecl>(Instantiation)) {
       Diag(PointOfInstantiation,
            diag::err_explicit_instantiation_undefined_func_template)
         << Pattern;
-    else
+      Note = diag::note_explicit_instantiation_here;
+    } else if (isa<TagDecl>(Instantiation)) {
       Diag(PointOfInstantiation, diag::err_template_instantiate_undefined)
         << (TSK != TSK_ImplicitInstantiation)
         << InstantiationTy;
-    Diag(Pattern->getLocation(), isa<FunctionDecl>(Instantiation)
-                                     ? diag::note_explicit_instantiation_here
-                                     : diag::note_template_decl_here);
+      Note = diag::note_template_decl_here;
+    } else {
+      assert(isa<VarDecl>(Instantiation) && "Must be a VarDecl!");
+      if (isa<VarTemplateSpecializationDecl>(Instantiation)) {
+        Diag(PointOfInstantiation,
+             diag::err_explicit_instantiation_undefined_var_template)
+          << Instantiation;
+        Instantiation->setInvalidDecl();
+      } else
+        Diag(PointOfInstantiation,
+             diag::err_explicit_instantiation_undefined_member)
+          << /*static data member*/ 2 << Instantiation->getDeclName()
+          << Instantiation->getDeclContext();
+      Note = diag::note_explicit_instantiation_here;
+    }
   }
+  if (Note) // Diagnostics were emitted.
+    Diag(Pattern->getLocation(), Note.getValue());
 
   // In general, Instantiation isn't marked invalid to get more than one
   // error for multiple undefined instantiations. But the code that does

diff --git a/lib/Sema/SemaTemplateInstantiateDecl.cpp b/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 09068d71ffbfdd455dafa5e693b48eedfbe5139e..911bc512c87e038af8e16f8022bc724b8f7d9861 100644 (file)
--- a/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -4068,6 +4068,10 @@ void Sema::InstantiateVariableDefinition(SourceLocation PointOfInstantiation,
       PrettyDeclStackTraceEntry CrashInfo(*this, Var, SourceLocation(),
                                           "instantiating variable initializer");
 
+      // The instantiation is visible here, even if it was first declared in an
+      // unimported module.
+      Var->setHidden(false);
+
       // If we're performing recursive template instantiation, create our own
       // queue of pending implicit instantiations that we will instantiate
       // later, while we're still within our own instantiation context.
@@ -4116,33 +4120,17 @@ void Sema::InstantiateVariableDefinition(SourceLocation PointOfInstantiation,
     Def = PatternDecl->getDefinition();
   }
 
-  // FIXME: Check that the definition is visible before trying to instantiate
-  // it. This requires us to track the instantiation stack in order to know
-  // which definitions should be visible.
+  TemplateSpecializationKind TSK = Var->getTemplateSpecializationKind();
 
   // If we don't have a definition of the variable template, we won't perform
   // any instantiation. Rather, we rely on the user to instantiate this
   // definition (or provide a specialization for it) in another translation
   // unit.
-  if (!Def) {
-    if (DefinitionRequired) {
-      if (VarSpec) {
-        Diag(PointOfInstantiation,
-             diag::err_explicit_instantiation_undefined_var_template) << Var;
-        Var->setInvalidDecl();
-      }
-      else
-        Diag(PointOfInstantiation,
-             diag::err_explicit_instantiation_undefined_member)
-            << 2 << Var->getDeclName() << Var->getDeclContext();
-      Diag(PatternDecl->getLocation(),
-           diag::note_explicit_instantiation_here);
-    } else if (Var->getTemplateSpecializationKind()
-                 == TSK_ExplicitInstantiationDefinition) {
+  if (!Def && !DefinitionRequired) {
+    if (TSK == TSK_ExplicitInstantiationDefinition) {
       PendingInstantiations.push_back(
         std::make_pair(Var, PointOfInstantiation));
-    } else if (Var->getTemplateSpecializationKind()
-                 == TSK_ImplicitInstantiation) {
+    } else if (TSK == TSK_ImplicitInstantiation) {
       // Warn about missing definition at the end of translation unit.
       if (AtEndOfTU && !getDiagnostics().hasErrorOccurred()) {
         Diag(PointOfInstantiation, diag::warn_var_template_missing)
@@ -4151,12 +4139,20 @@ void Sema::InstantiateVariableDefinition(SourceLocation PointOfInstantiation,
         if (getLangOpts().CPlusPlus11)
           Diag(PointOfInstantiation, diag::note_inst_declaration_hint) << Var;
       }
+      return;
     }
 
-    return;
   }
 
-  TemplateSpecializationKind TSK = Var->getTemplateSpecializationKind();
+  // FIXME: We need to track the instantiation stack in order to know which
+  // definitions should be visible within this instantiation.
+  // FIXME: Produce diagnostics when Var->getInstantiatedFromStaticDataMember().
+  if (DiagnoseUninstantiableTemplate(PointOfInstantiation, Var,
+                                     /*InstantiatedFromMember*/false,
+                                     PatternDecl, Def, TSK,
+                                     /*Complain*/DefinitionRequired))
+    return;
+
 
   // Never instantiate an explicit specialization.
   if (TSK == TSK_ExplicitSpecialization)

diff --git a/lib/Sema/SemaType.cpp b/lib/Sema/SemaType.cpp
index d13561b19b5404164b42e9edd5038a9197633399..cfbfc3b09f2e60c38f0ba89964893b2fb2dc7ab5 100644 (file)
--- a/lib/Sema/SemaType.cpp
+++ b/lib/Sema/SemaType.cpp
@@ -6888,6 +6888,10 @@ bool Sema::hasVisibleDefinition(NamedDecl *D, NamedDecl **Suggested,
     if (auto *Pattern = FD->getTemplateInstantiationPattern())
       FD = Pattern;
     D = FD->getDefinition();
+  } else if (auto *VD = dyn_cast<VarDecl>(D)) {
+    if (auto *Pattern = VD->getTemplateInstantiationPattern())
+      VD = Pattern;
+    D = VD->getDefinition();
   }
   assert(D && "missing definition for pattern of instantiated definition");
 

diff --git a/lib/Serialization/ASTReaderDecl.cpp b/lib/Serialization/ASTReaderDecl.cpp
index 19113da7e3c5e842b59002020f1cec171188ee26..94097cd2e1baf5a44f08783ed29627c1876143b8 100644 (file)
--- a/lib/Serialization/ASTReaderDecl.cpp
+++ b/lib/Serialization/ASTReaderDecl.cpp
@@ -1216,6 +1216,7 @@ ASTDeclReader::RedeclarableResult ASTDeclReader::VisitVarDeclImpl(VarDecl *VD) {
   VD->VarDeclBits.TSCSpec = Record[Idx++];
   VD->VarDeclBits.InitStyle = Record[Idx++];
   if (!isa<ParmVarDecl>(VD)) {
+    VD->NonParmVarDeclBits.IsThisDeclarationADemotedDefinition = Record[Idx++];
     VD->NonParmVarDeclBits.ExceptionVar = Record[Idx++];
     VD->NonParmVarDeclBits.NRVOVariable = Record[Idx++];
     VD->NonParmVarDeclBits.CXXForRangeDecl = Record[Idx++];
@@ -3067,6 +3068,29 @@ void ASTDeclReader::attachPreviousDeclImpl(ASTReader &Reader,
 }
 
 namespace clang {
+template<>
+void ASTDeclReader::attachPreviousDeclImpl(ASTReader &Reader,
+                                           Redeclarable<VarDecl> *D,
+                                           Decl *Previous, Decl *Canon) {
+  VarDecl *VD = static_cast<VarDecl*>(D);
+  VarDecl *PrevVD = cast<VarDecl>(Previous);
+  D->RedeclLink.setPrevious(PrevVD);
+  D->First = PrevVD->First;
+
+  // We should keep at most one definition on the chain.
+  // FIXME: Cache the definition once we've found it. Building a chain with
+  // N definitions currently takes O(N^2) time here.
+  if (VD->isThisDeclarationADefinition() == VarDecl::Definition) {
+    for (VarDecl *CurD = PrevVD; CurD; CurD = CurD->getPreviousDecl()) {
+      if (CurD->isThisDeclarationADefinition() == VarDecl::Definition) {
+        Reader.mergeDefinitionVisibility(CurD, VD);
+        VD->demoteThisDefinitionToDeclaration();
+        break;
+      }
+    }
+  }
+}
+
 template<>
 void ASTDeclReader::attachPreviousDeclImpl(ASTReader &Reader,
                                            Redeclarable<FunctionDecl> *D,

diff --git a/lib/Serialization/ASTWriterDecl.cpp b/lib/Serialization/ASTWriterDecl.cpp
index a0fc1559ce93962f34edb714580b2bd9054a0dd0..21468619dba994afb003cb595bd45627229ac231 100644 (file)
--- a/lib/Serialization/ASTWriterDecl.cpp
+++ b/lib/Serialization/ASTWriterDecl.cpp
@@ -894,6 +894,7 @@ void ASTDeclWriter::VisitVarDecl(VarDecl *D) {
   Record.push_back(D->getTSCSpec());
   Record.push_back(D->getInitStyle());
   if (!isa<ParmVarDecl>(D)) {
+    Record.push_back(D->isThisDeclarationADemotedDefinition());
     Record.push_back(D->isExceptionVariable());
     Record.push_back(D->isNRVOVariable());
     Record.push_back(D->isCXXForRangeDecl());
@@ -998,6 +999,8 @@ void ASTDeclWriter::VisitParmVarDecl(ParmVarDecl *D) {
   // Check things we know are true of *every* PARM_VAR_DECL, which is more than
   // just us assuming it.
   assert(!D->getTSCSpec() && "PARM_VAR_DECL can't use TLS");
+  assert(!D->isThisDeclarationADemotedDefinition()
+         && "PARM_VAR_DECL can't be demoted definition.");
   assert(D->getAccess() == AS_none && "PARM_VAR_DECL can't be public/private");
   assert(!D->isExceptionVariable() && "PARM_VAR_DECL can't be exception var");
   assert(D->getPreviousDecl() == nullptr && "PARM_VAR_DECL can't be redecl");
@@ -1957,6 +1960,7 @@ void ASTWriter::WriteDeclAbbrevs() {
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // SClass
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // TSCSpec
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // InitStyle
+  Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsThisDeclarationADemotedDefinition
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isExceptionVariable
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isNRVOVariable
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCXXForRangeDecl

diff --git a/test/Modules/Inputs/PR28752/Subdir1/b.h b/test/Modules/Inputs/PR28752/Subdir1/b.h
new file mode 100644 (file)
index 0000000..4d8de21
--- /dev/null
+++ b/test/Modules/Inputs/PR28752/Subdir1/b.h
@@ -0,0 +1,4 @@
+#include <vector>
+
+template<typename T> struct A { static bool b; };
+template<typename T> bool A<T>::b;

diff --git a/test/Modules/Inputs/PR28752/Subdir1/c.h b/test/Modules/Inputs/PR28752/Subdir1/c.h
new file mode 100644 (file)
index 0000000..38822fb
--- /dev/null
+++ b/test/Modules/Inputs/PR28752/Subdir1/c.h
@@ -0,0 +1,2 @@
+template<typename T> struct A { static bool b; };
+template<typename T> bool A<T>::b;

diff --git a/test/Modules/Inputs/PR28752/Subdir1/module.modulemap b/test/Modules/Inputs/PR28752/Subdir1/module.modulemap
new file mode 100644 (file)
index 0000000..8d3bfe9
--- /dev/null
+++ b/test/Modules/Inputs/PR28752/Subdir1/module.modulemap
@@ -0,0 +1,5 @@
+module b {
+  module "b.h" { header "b.h" export * }
+  module "c.h" { header "c.h" export * }
+  export *
+}

diff --git a/test/Modules/Inputs/PR28752/a.h b/test/Modules/Inputs/PR28752/a.h
new file mode 100644 (file)
index 0000000..3b3a25f
--- /dev/null
+++ b/test/Modules/Inputs/PR28752/a.h
@@ -0,0 +1 @@
+#include <vector>

diff --git a/test/Modules/Inputs/PR28752/module.modulemap b/test/Modules/Inputs/PR28752/module.modulemap
new file mode 100644 (file)
index 0000000..caf888f
--- /dev/null
+++ b/test/Modules/Inputs/PR28752/module.modulemap
@@ -0,0 +1 @@
+module a { header "a.h" export * }

diff --git a/test/Modules/Inputs/PR28752/vector b/test/Modules/Inputs/PR28752/vector
new file mode 100644 (file)
index 0000000..fc5dafa
--- /dev/null
+++ b/test/Modules/Inputs/PR28752/vector
@@ -0,0 +1,28 @@
+#ifndef VECTOR
+#define VECTOR
+template <bool, typename> struct B;
+template <typename _Tp> struct B<true, _Tp> { typedef _Tp type; };
+namespace std {
+template <typename> struct D {
+
+  template <typename _Alloc2> struct F {
+    static const bool value = 0;
+  };
+
+  template <typename _Alloc2>
+  typename B<F<_Alloc2>::value, _Alloc2>::type _S_select(_Alloc2);
+  template <typename _Alloc2>
+  static
+  typename B<!F<_Alloc2>::value, _Alloc2>::type _S_select(_Alloc2);
+};
+template <typename _Alloc>
+template <typename _Alloc2>
+const bool D<_Alloc>::F<_Alloc2>::value;
+
+template <typename> class vector {
+public:
+  vector(int);
+  vector(vector &) : vector(D<bool>::_S_select((bool)0)) {}
+};
+}
+#endif // VECTOR
\ No newline at end of file

diff --git a/test/Modules/pr28752.cpp b/test/Modules/pr28752.cpp
new file mode 100644 (file)
index 0000000..1c78961
--- /dev/null
+++ b/test/Modules/pr28752.cpp
@@ -0,0 +1,22 @@
+// RUN: rm -rf %t
+// RUN: %clang_cc1 -std=c++11 -nostdsysteminc -I%S/Inputs/PR28752 -verify %s
+// RUN: %clang_cc1 -std=c++11 -nostdsysteminc -fmodules -fmodule-map-file=%S/Inputs/PR28752/Subdir1/module.modulemap -fmodule-map-file=%S/Inputs/PR28752/module.modulemap -fmodules-cache-path=%t -I%S/Inputs/PR28752 -I%S/Inputs/PR28752/Subdir1 -verify %s -fmodules-local-submodule-visibility
+
+#include "a.h"
+#include "Subdir1/c.h"
+#include <vector>
+
+class TClingClassInfo {
+  std::vector<int> fIterStack;
+};
+
+TClingClassInfo *a;
+class TClingBaseClassInfo {
+  TClingBaseClassInfo() { new TClingClassInfo(*a); }
+};
+
+namespace { struct Q; }
+bool *p = &A<Q>::b;
+
+// expected-no-diagnostics
+