[modules] Fix adding a templated friend functions to a namespace from another module.

When clang adds argument dependent lookup candidates, it can perform template
instantiation. For example, it can instantiate a templated friend function and
register it in the enclosing namespace's lookup table.

Fixes https://llvm.org/bugs/show_bug.cgi?id=24954

Reviewed by Richard Smith.

llvm-svn: 263634

4 files changed, 56 insertions, 0 deletions

diff --git a/clang/test/Modules/Inputs/PR24954/A.h b/clang/test/Modules/Inputs/PR24954/A.h
new file mode 100644
index 00000000000..5e5d5bf92ce
--- /dev/null
+++ b/clang/test/Modules/Inputs/PR24954/A.h
@@ -0,0 +1,10 @@
+#include "B.h"
+
+template <class T>
+class Expr {
+public:
+   void print(B::basic_ostream<char>& os) {
+     os << B::setw(42);
+     os << B::endl;
+  }
+};
diff --git a/clang/test/Modules/Inputs/PR24954/B.h b/clang/test/Modules/Inputs/PR24954/B.h
new file mode 100644
index 00000000000..a8ddc718927
--- /dev/null
+++ b/clang/test/Modules/Inputs/PR24954/B.h
@@ -0,0 +1,30 @@
+namespace B {
+
+  template <class _CharT>
+  struct basic_ostream {
+    basic_ostream& operator<<(basic_ostream& (*__pf)());
+  };
+
+
+  template <class _CharT> basic_ostream<_CharT>&
+  endl();
+
+  struct S1 {
+    template <class _CharT> friend void
+    operator<<(basic_ostream<_CharT>& __os, const S1& __x);
+  };
+
+  S1 setw(int __n);
+
+  template <class _CharT> class S2;
+
+  template <class _CharT> void
+  operator<<(basic_ostream<_CharT>& __os, const S2<_CharT>& __x);
+
+  template <class _CharT>
+  struct S2 {
+    template <class _Cp> friend void
+    operator<<(basic_ostream<_Cp>& __os, const S2<_Cp>& __x);
+  };
+
+}
diff --git a/clang/test/Modules/Inputs/PR24954/module.modulemap b/clang/test/Modules/Inputs/PR24954/module.modulemap
new file mode 100644
index 00000000000..49374181d75
--- /dev/null
+++ b/clang/test/Modules/Inputs/PR24954/module.modulemap
@@ -0,0 +1,9 @@
+module A {
+  header "A.h"
+  export *
+}
+
+module B {
+  header "B.h"
+  export *
+}
diff --git a/clang/test/Modules/pr24954.cpp b/clang/test/Modules/pr24954.cpp
new file mode 100644
index 00000000000..407ee06e402
--- /dev/null
+++ b/clang/test/Modules/pr24954.cpp
@@ -0,0 +1,7 @@
+// RUN: rm -rf %t
+// RUN: %clang_cc1 -I%S/Inputs/PR24954 -verify %s
+// RUN: %clang_cc1 -fmodules -fimplicit-module-maps -fmodules-cache-path=%t -I%S/Inputs/PR24954 -verify %s
+
+#include "A.h"
+
+// expected-no-diagnostics