When deserializing an anonymous namespace from a module, do not attach

the anonymous namespace to its parent. Semantically, this means that
the anonymous namespaces defined in one module are distinct from the
anonymous namespaces defined in another module.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@147782 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 64 insertions, 8 deletions

diff --git a/lib/Serialization/ASTReaderDecl.cpp b/lib/Serialization/ASTReaderDecl.cpp
index f6c9bfaa57..6b8a72f807 100644
--- a/lib/Serialization/ASTReaderDecl.cpp
+++ b/lib/Serialization/ASTReaderDecl.cpp
@@ -978,10 +978,12 @@ void ASTDeclReader::VisitNamespaceDecl(NamespaceDecl *D) {
   mergeRedeclarable(D, Redecl);
 
   if (Redecl.getFirstID() == ThisDeclID) {
-    // FIXME: If there's already an anonymous namespace, do we merge it with
-    // this one? Or do we, when loading modules, just forget about anonymous
-    // namespace entirely?
-    D->setAnonymousNamespace(ReadDeclAs<NamespaceDecl>(Record, Idx));
+    // Each module has its own anonymous namespace, which is disjoint from
+    // any other module's anonymous namespaces, so don't attach the anonymous
+    // namespace at all.
+    NamespaceDecl *Anon = ReadDeclAs<NamespaceDecl>(Record, Idx);
+    if (F.Kind != MK_Module)
+      D->setAnonymousNamespace(Anon);
   } else {
     // Link this namespace back to the first declaration, which has already
     // been deserialized.
@@ -2484,10 +2486,16 @@ void ASTDeclReader::UpdateDecl(Decl *D, ModuleFile &ModuleFile,
     case UPD_CXX_ADDED_ANONYMOUS_NAMESPACE: {
       NamespaceDecl *Anon
         = Reader.ReadDeclAs<NamespaceDecl>(ModuleFile, Record, Idx);
-      if (TranslationUnitDecl *TU = dyn_cast<TranslationUnitDecl>(D))
-        TU->setAnonymousNamespace(Anon);
-      else
-        cast<NamespaceDecl>(D)->setAnonymousNamespace(Anon);
+      
+      // Each module has its own anonymous namespace, which is disjoint from
+      // any other module's anonymous namespaces, so don't attach the anonymous
+      // namespace at all.
+      if (ModuleFile.Kind != MK_Module) {
+        if (TranslationUnitDecl *TU = dyn_cast<TranslationUnitDecl>(D))
+          TU->setAnonymousNamespace(Anon);
+        else
+          cast<NamespaceDecl>(D)->setAnonymousNamespace(Anon);
+      }
       break;
     }
 
diff --git a/test/Modules/Inputs/namespaces-left.h b/test/Modules/Inputs/namespaces-left.h
index ea2ae2b9ce..7e9002aea8 100644
--- a/test/Modules/Inputs/namespaces-left.h
+++ b/test/Modules/Inputs/namespaces-left.h
@@ -37,3 +37,17 @@ namespace N9 {
 namespace N10 {
   int &f(int);
 }
+
+namespace N11 {
+  namespace {
+    class Foo;
+  }
+  Foo *getFoo();
+}
+
+namespace N12 {
+  namespace {
+    class Foo;
+  }
+  Foo *getFoo();
+}
diff --git a/test/Modules/Inputs/namespaces-right.h b/test/Modules/Inputs/namespaces-right.h
index d103c00c82..b18aeb4478 100644
--- a/test/Modules/Inputs/namespaces-right.h
+++ b/test/Modules/Inputs/namespaces-right.h
@@ -39,3 +39,23 @@ namespace N9 {
 namespace N10 {
   int &f(int);
 }
+
+
+
+
+
+
+
+namespace N11 {
+  namespace {
+    class Foo;
+  }
+  void consumeFoo(Foo*);
+}
+
+namespace N12 {
+  namespace {
+    class Foo;
+  }
+  void consumeFoo(Foo*);
+}
diff --git a/test/Modules/Inputs/namespaces-top.h b/test/Modules/Inputs/namespaces-top.h
index a69f43f183..0c607f5285 100644
--- a/test/Modules/Inputs/namespaces-top.h
+++ b/test/Modules/Inputs/namespaces-top.h
@@ -9,3 +9,6 @@ namespace N2 {
 namespace N3 { 
   int& f(int);
 }
+
+namespace N12 { }
+
diff --git a/test/Modules/namespaces.cpp b/test/Modules/namespaces.cpp
index 9ef966ac01..b60f75cff6 100644
--- a/test/Modules/namespaces.cpp
+++ b/test/Modules/namespaces.cpp
@@ -47,3 +47,14 @@ void testMergedMerged() {
   int &ir2 = N9::f(17);
   int &ir3 = N10::f(17);
 }
+
+// Test merging when using anonymous namespaces, which does not
+// actually perform any merging.
+// other file: expected-note{{passing argument to parameter here}}
+void testAnonymousNotMerged() {
+  N11::consumeFoo(N11::getFoo()); // expected-error{{cannot initialize a parameter of type 'N11::<anonymous>::Foo *' with an rvalue of type 'N11::<anonymous>::Foo *'}}
+  N12::consumeFoo(N12::getFoo()); // expected-error{{cannot initialize a parameter of type 'N12::<anonymous>::Foo *' with an rvalue of type 'N12::<anonymous>::Foo *'}}  
+}
+
+
+// other file: expected-note{{passing argument to parameter here}}