6 files changed, 74 insertions, 4 deletions
diff --git a/clang/test/Modules/Inputs/codegen-nodep/foo.h b/clang/test/Modules/Inputs/codegen-nodep/foo.h
new file mode 100644
index 00000000000..af91e8d263b
--- /dev/null
+++ b/clang/test/Modules/Inputs/codegen-nodep/foo.h
@@ -0,0 +1,5 @@
+template <typename T>
+void ftempl() {
+}
+inline void f() {
+}
diff --git a/clang/test/Modules/Inputs/codegen-nodep/foo.modulemap b/clang/test/Modules/Inputs/codegen-nodep/foo.modulemap
new file mode 100644
index 00000000000..2e095d2794c
--- /dev/null
+++ b/clang/test/Modules/Inputs/codegen-nodep/foo.modulemap
@@ -0,0 +1 @@
+module foo { header "foo.h" }
diff --git a/clang/test/Modules/Inputs/codegen/foo.h b/clang/test/Modules/Inputs/codegen/foo.h
index 3fcab718573..e77e8d1824e 100644
--- a/clang/test/Modules/Inputs/codegen/foo.h
+++ b/clang/test/Modules/Inputs/codegen/foo.h
@@ -2,3 +2,29 @@ inline void f1(const char* fmt, ...) {
   __builtin_va_list args;
   __builtin_va_start(args, fmt);
 }
+
+struct non_trivial_dtor {
+  ~non_trivial_dtor();
+};
+
+struct implicit_dtor {
+  non_trivial_dtor d;
+};
+
+struct uninst_implicit_dtor {
+  non_trivial_dtor d;
+};
+
+inline void use_implicit_dtor() {
+  implicit_dtor d;
+}
+
+template <typename T>
+void inst() {
+}
+
+inline void inst_decl() {
+  // cause inst<int>'s declaration to be instantiated, without a definition.
+  (void)sizeof(&inst<int>);
+  inst<float>();
+}
diff --git a/clang/test/Modules/Inputs/codegen/use.cpp b/clang/test/Modules/Inputs/codegen/use.cpp
new file mode 100644
index 00000000000..cd1a4a642d0
--- /dev/null
+++ b/clang/test/Modules/Inputs/codegen/use.cpp
@@ -0,0 +1,8 @@
+#include "foo.h"
+void non_modular_use_of_implicit_dtor() {
+  implicit_dtor d1;
+  uninst_implicit_dtor d2;
+}
+void use_of_instantiated_declaration_without_definition() {
+  inst<int>();
+}
diff --git a/clang/test/Modules/codegen-nodep.test b/clang/test/Modules/codegen-nodep.test
new file mode 100644
index 00000000000..cb2b4e37e9d
--- /dev/null
+++ b/clang/test/Modules/codegen-nodep.test
@@ -0,0 +1,13 @@
+RUN: rm -rf %t
+REQUIRES: x86-registered-target
+
+RUN: %clang_cc1 -triple=x86_64-linux-gnu -fmodules-codegen -x c++ -fmodules \
+RUN:            -emit-module -fmodule-name=foo \
+RUN:            %S/Inputs/codegen-nodep/foo.modulemap -o - \
+RUN:          | llvm-bcanalyzer - -dump \
+RUN:          | FileCheck %s
+
+Ensure there's only one modular codegen decl - the sentinel plain inline
+function, not any for the function template.
+
+CHECK: <MODULAR_CODEGEN_DECLS op0={{[0-9]+}}/>
diff --git a/clang/test/Modules/codegen.test b/clang/test/Modules/codegen.test
index f1823d55baf..6807640e603 100644
--- a/clang/test/Modules/codegen.test
+++ b/clang/test/Modules/codegen.test
@@ -3,8 +3,25 @@ REQUIRES: x86-registered-target
 
 RUN: %clang_cc1 -triple=x86_64-linux-gnu -fmodules-codegen -x c++ -fmodules -emit-module -fmodule-name=foo %S/Inputs/codegen/foo.modulemap -o %t/foo.pcm
 
-RUN: %clang_cc1 -triple x86_64-linux-gnu -emit-llvm -o - %t/foo.pcm | FileCheck %s
+RUN: %clang_cc1 -triple x86_64-linux-gnu -emit-llvm -o - %t/foo.pcm | FileCheck --check-prefix=FOO --check-prefix=BOTH %s
+RUN: %clang_cc1 -triple x86_64-linux-gnu -emit-llvm -o - -fmodules -fmodule-file=%t/foo.pcm %S/Inputs/codegen/use.cpp | FileCheck --check-prefix=BOTH --check-prefix=USE %s
 
-CHECK: $_Z2f1PKcz = comdat any
-CHECK: define weak_odr void @_Z2f1PKcz(i8* %fmt, ...) #{{[0-9]+}} comdat
-CHECK:   call void @llvm.va_start(i8* %{{[a-zA-Z0-9]*}})
+FOO: $_Z2f1PKcz = comdat any
+FOO: $_ZN13implicit_dtorD1Ev = comdat any
+USE: $_Z4instIiEvv = comdat any
+FOO: $_ZN13implicit_dtorD2Ev = comdat any
+FOO: define weak_odr void @_Z2f1PKcz(i8* %fmt, ...) #{{[0-9]+}} comdat
+FOO:   call void @llvm.va_start(i8* %{{[a-zA-Z0-9]*}})
+
+Test that implicit special members are emitted into the FOO module if they're
+ODR used there, otherwise emit them linkonce_odr as usual in the use.
+
+FIXME: Proactively instantiate any valid implicit special members to emit them into the module object.
+
+FOO: define weak_odr void @_ZN13implicit_dtorD1Ev
+FOO: define weak_odr void @_Z4instIfEvv
+FOO: define weak_odr void @_ZN13implicit_dtorD2Ev
+
+USE: define linkonce_odr void @_ZN20uninst_implicit_dtorD1Ev
+USE: define linkonce_odr void @_Z4instIiEvv
+USE: define linkonce_odr void @_ZN20uninst_implicit_dtorD2Ev