Implement redeclaration merging for namespaces defined in distinct

modules. Teach name lookup into namespaces to search in each of the
merged DeclContexts as well as the (now-primary) DeclContext. This
supports the common case where two different modules put something
into the same namespace.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@147778 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 21 insertions, 0 deletions

diff --git a/test/Modules/namespaces.cpp b/test/Modules/namespaces.cpp
index 75557ba4c1..e1a8d6e8b0 100644
--- a/test/Modules/namespaces.cpp
+++ b/test/Modules/namespaces.cpp
@@ -1,6 +1,10 @@
 // RUN: rm -rf %t
 // RUN: %clang_cc1 -x objective-c++ -fmodules -fmodule-cache-path %t -I %S/Inputs %s -verify
 
+namespace N6 {
+  char &f(char);
+}
+
 @import namespaces_left;
 @import namespaces_right;
 
@@ -13,3 +17,20 @@ void test() {
   double &dr1 = N2::f(1.0);
   double &dr2 = N3::f(1.0);
 }
+
+// Test namespaces merged without a common first declaration.
+namespace N5 {
+  char &f(char);
+}
+
+void testMerged() {
+  int &ir1 = N5::f(17);
+  int &ir2 = N6::f(17);
+  int &ir3 = N7::f(17);
+  double &fr1 = N5::f(1.0);
+  double &fr2 = N6::f(1.0);
+  double &fr3 = N7::f(1.0);
+  char &cr1 = N5::f('a');
+  char &cr2 = N6::f('b');
+}
+