-gmodules: Emit debug info for implicit module imports via #include.

When a type is only used as a template parameter and that type is the
only type imported from another #include'd module, no skeleton CU for
that module is generated, so a consumer doesn't know where to find the
type definition. By emitting an import declaration, we can force a
skeleton CU to be generated for each imported module.

rdar://problem/36266156

llvm-svn: 321754

3 files changed, 19 insertions, 3 deletions

diff --git a/clang/test/Modules/ExtDebugInfo.cpp b/clang/test/Modules/ExtDebugInfo.cpp
index 97386bc4d00..c57f1f034eb 100644
--- a/clang/test/Modules/ExtDebugInfo.cpp
+++ b/clang/test/Modules/ExtDebugInfo.cpp
@@ -187,7 +187,7 @@ void foo() {
 
 // CHECK: !DIGlobalVariable(name: "anon_enum", {{.*}}, type: ![[ANON_ENUM:[0-9]+]]
 // CHECK: !DICompositeType(tag: DW_TAG_enumeration_type, scope: ![[NS]],
-// CHECK-SAME:             line: 16
+// CHECK-SAME:             line: 19
 
 // CHECK: !DIGlobalVariable(name: "GlobalUnion",
 // CHECK-SAME:              type: ![[GLOBAL_UNION:[0-9]+]]
diff --git a/clang/test/Modules/Inputs/DebugCXX.h b/clang/test/Modules/Inputs/DebugCXX.h
index 1ccf8d302f1..8f83c0bc69d 100644
--- a/clang/test/Modules/Inputs/DebugCXX.h
+++ b/clang/test/Modules/Inputs/DebugCXX.h
@@ -1,4 +1,7 @@
 /* -*- C++ -*- */
+
+#include "dummy.h"
+
 namespace DebugCXX {
   // Records.
   struct Struct {
diff --git a/clang/test/Modules/ModuleDebugInfo.cpp b/clang/test/Modules/ModuleDebugInfo.cpp
index 008b3e4f2ba..f0d88376704 100644
--- a/clang/test/Modules/ModuleDebugInfo.cpp
+++ b/clang/test/Modules/ModuleDebugInfo.cpp
@@ -5,12 +5,13 @@
 
 // Modules:
 // RUN: rm -rf %t
-// RUN: %clang_cc1 -triple %itanium_abi_triple -x objective-c++ -std=c++11 -debug-info-kind=limited -fmodules -fmodule-format=obj -fimplicit-module-maps -DMODULES -fmodules-cache-path=%t %s -I %S/Inputs -I %t -emit-llvm -o %t.ll -mllvm -debug-only=pchcontainer &>%t-mod.ll
+// RUN: %clang_cc1 -triple %itanium_abi_triple -x objective-c++ -std=c++11 -debugger-tuning=lldb -debug-info-kind=limited -fmodules -fmodule-format=obj -fimplicit-module-maps -DMODULES -fmodules-cache-path=%t %s -I %S/Inputs -I %t -emit-llvm -o %t.ll -mllvm -debug-only=pchcontainer &>%t-mod.ll
 // RUN: cat %t-mod.ll | FileCheck %s
 // RUN: cat %t-mod.ll | FileCheck --check-prefix=CHECK-NEG %s
+// RUN: cat %t-mod.ll | FileCheck --check-prefix=CHECK-MOD %s
 
 // PCH:
-// RUN: %clang_cc1 -triple %itanium_abi_triple -x c++ -std=c++11 -emit-pch -fmodule-format=obj -I %S/Inputs -o %t.pch %S/Inputs/DebugCXX.h -mllvm -debug-only=pchcontainer &>%t-pch.ll
+// RUN: %clang_cc1 -triple %itanium_abi_triple -x c++ -std=c++11  -debugger-tuning=lldb -emit-pch -fmodule-format=obj -I %S/Inputs -o %t.pch %S/Inputs/DebugCXX.h -mllvm -debug-only=pchcontainer &>%t-pch.ll
 // RUN: cat %t-pch.ll | FileCheck %s
 // RUN: cat %t-pch.ll | FileCheck --check-prefix=CHECK-NEG %s
 
@@ -18,6 +19,9 @@
 @import DebugCXX;
 #endif
 
+// CHECK-MOD: distinct !DICompileUnit(language: DW_LANG_{{.*}}C_plus_plus,
+// CHECK-MOD: distinct !DICompileUnit(language: DW_LANG_{{.*}}C_plus_plus,
+
 // CHECK: distinct !DICompileUnit(language: DW_LANG_{{.*}}C_plus_plus,
 // CHECK-SAME:                    isOptimized: false,
 // CHECK-NOT:                     splitDebugFilename:
@@ -27,6 +31,8 @@
 // CHECK-SAME:             identifier: "_ZTSN8DebugCXX4EnumE")
 // CHECK: !DINamespace(name: "DebugCXX"
 
+// CHECK-MOD: ![[DEBUGCXX:.*]] = !DIModule(scope: null, name: "DebugCXX
+
 // CHECK: !DICompositeType(tag: DW_TAG_enumeration_type,
 // CHECK-NOT:              name:
 // CHECK-SAME:             )
@@ -150,4 +156,11 @@
 // CHECK-SAME:                             name: "WithSpecializedBase<float>",
 // CHECK-SAME:                             flags: DIFlagFwdDecl,
 
+// CHECK-MOD: !DIImportedEntity(tag: DW_TAG_imported_declaration, scope: ![[DEBUGCXX]],
+// CHECK-MOD-SAME:              entity: ![[DUMMY:[0-9]+]],
+// CHECK-MOD-SAME:              line: 3)
+// CHECK-MOD: ![[DUMMY]] = !DIModule(scope: null, name: "dummy",
+// CHECK-MOD: distinct !DICompileUnit(language: DW_LANG_ObjC_plus_plus,
+// CHECK-MOD-SAME:  splitDebugFilename: "{{.*}}dummy{{.*}}.pcm",
+
 // CHECK-NEG-NOT: !DICompositeType(tag: DW_TAG_structure_type, name: "PureForwardDecl"