Revert "Revert "Debug Info: Using declarations/DW_TAG_imported_declaration of variables, types, and functions.""

This reverts commit r181947 (git d2990ce56a16050cac0d7937ec9919ff54c6df62 )

This addresses one of the two issues identified in r181947, ensuring
that types imported via using declarations only result in a declaration
being emitted for the type, not a definition. The second issue (emitting
using declarations that are unused) is hopefully an acceptable increase
as the real fix for this would be a bit difficult (probably at best we
could record which using directives were involved in lookups - but may
not have been the result of the lookup).

This also ensures that DW_TAG_imported_declarations (& directives) are
not emitted in line-tables-only mode as well as ensuring that typedefs
only require/emit declarations (rather than definitions) for referenced
types.

llvm-svn: 182231

1 files changed, 43 insertions, 13 deletions

diff --git a/clang/test/CodeGenCXX/debug-info-namespace.cpp b/clang/test/CodeGenCXX/debug-info-namespace.cpp
index 13a7914b7be..0f4e73cbe36 100644
--- a/clang/test/CodeGenCXX/debug-info-namespace.cpp
+++ b/clang/test/CodeGenCXX/debug-info-namespace.cpp
@@ -1,9 +1,16 @@
-// RUN: %clang  -g -S -emit-llvm %s -o - | FileCheck %s
+// RUN: %clang -g -S -emit-llvm %s -o - | FileCheck %s
+// RUN: %clang -g -gline-tables-only -S -emit-llvm %s -o - | FileCheck -check-prefix=CHECK-GMLT %s
+// RUN: %clang -g -fno-limit-debug-info -S -emit-llvm %s -o - | FileCheck -check-prefix=CHECK-NOLIMIT %s
 
 namespace A {
 #line 1 "foo.cpp"
 namespace B {
 int i;
+void f1() { }
+void f1(int) { }
+struct foo;
+struct bar { };
+typedef bar baz;
 }
 using namespace B;
 }
@@ -16,22 +23,45 @@ int func(bool b) {
     return i;
   }
   using namespace A;
-  return B::i;
+  using B::foo;
+  using B::bar;
+  using B::f1;
+  using B::i;
+  using B::baz;
+  return i;
 }
 
+// This should work even if 'i' and 'func' were declarations & not definitions,
+// but it doesn't yet.
+
 // CHECK: [[CU:![0-9]*]] = {{.*}}[[MODULES:![0-9]*]], metadata !""} ; [ DW_TAG_compile_unit ]
 // CHECK: [[FILE:![0-9]*]] {{.*}}debug-info-namespace.cpp"
-// CHECK: [[FUNC:![0-9]*]] {{.*}} ; [ DW_TAG_subprogram ] [line 9] [def] [func]
-// CHECK: [[FILE2:![0-9]*]]} ; [ DW_TAG_file_type ] [{{.*}}foo.cpp]
-// CHECK: [[VAR:![0-9]*]] = {{.*}}, metadata [[NS:![0-9]*]], metadata !"i", {{.*}} ; [ DW_TAG_variable ] [i]
-// CHECK: [[NS]] = {{.*}}, metadata [[FILE2]], metadata [[CTXT:![0-9]*]], {{.*}} ; [ DW_TAG_namespace ] [B] [line 1]
-// CHECK: [[CTXT]] = {{.*}}, metadata [[FILE]], null, {{.*}} ; [ DW_TAG_namespace ] [A] [line 3]
-// CHECK: [[MODULES]] = metadata !{metadata [[M1:![0-9]*]], metadata [[M2:![0-9]*]], metadata [[M3:![0-9]*]], metadata [[M4:![0-9]*]]}
-// CHECK: [[M1]] = metadata !{i32 {{[0-9]*}}, metadata [[CTXT]], metadata [[NS]], i32 4} ; [ DW_TAG_imported_module ]
-// CHECK: [[M2]] = metadata !{i32 {{[0-9]*}}, metadata [[CU]], metadata [[CTXT]], i32 7} ; [ DW_TAG_imported_module ]
-// CHECK: [[M3]] = metadata !{i32 {{[0-9]*}}, metadata [[LEX:![0-9]*]], metadata [[NS]], i32 11} ; [ DW_TAG_imported_module ]
-// CHECK: [[LEX]] = metadata !{i32 {{[0-9]*}}, metadata [[FILE2]], metadata [[FUNC]], i32 10, i32 0, i32 0} ; [ DW_TAG_lexical_block ]
-// CHECK: [[M4]] = metadata !{i32 {{[0-9]*}}, metadata [[FUNC]], metadata [[CTXT]], i32 14} ; [ DW_TAG_imported_module ]
+// CHECK: [[FOOCPP:![0-9]*]] = metadata !{metadata !"foo.cpp", {{.*}}
+// CHECK: [[NS:![0-9]*]] = {{.*}}, metadata [[FILE2:![0-9]*]], metadata [[CTXT:![0-9]*]], {{.*}} ; [ DW_TAG_namespace ] [B] [line 1]
+// CHECK: [[CTXT]] = {{.*}}, metadata [[FILE]], null, {{.*}} ; [ DW_TAG_namespace ] [A] [line 5]
+// CHECK: [[F1:![0-9]*]] {{.*}} ; [ DW_TAG_subprogram ] [line 4] [def] [f1]
+// CHECK: [[FUNC:![0-9]*]] {{.*}} ; [ DW_TAG_subprogram ] [line 14] [def] [func]
+// CHECK: [[FILE2]]} ; [ DW_TAG_file_type ] [{{.*}}foo.cpp]
+// CHECK: [[I:![0-9]*]] = {{.*}}, metadata [[NS]], metadata !"i", {{.*}} ; [ DW_TAG_variable ] [i]
+// CHECK: [[MODULES]] = metadata !{metadata [[M1:![0-9]*]], metadata [[M2:![0-9]*]], metadata [[M3:![0-9]*]], metadata [[M4:![0-9]*]], metadata [[M5:![0-9]*]], metadata [[M6:![0-9]*]], metadata [[M7:![0-9]*]], metadata [[M8:![0-9]*]], metadata [[M9:![0-9]*]]}
+// CHECK: [[M1]] = metadata !{i32 {{[0-9]*}}, metadata [[CTXT]], metadata [[NS]], i32 9} ; [ DW_TAG_imported_module ]
+// CHECK: [[M2]] = metadata !{i32 {{[0-9]*}}, metadata [[CU]], metadata [[CTXT]], i32 12} ; [ DW_TAG_imported_module ]
+// CHECK: [[M3]] = metadata !{i32 {{[0-9]*}}, metadata [[LEX:![0-9]*]], metadata [[NS]], i32 16} ; [ DW_TAG_imported_module ]
+// CHECK: [[LEX]] = metadata !{i32 {{[0-9]*}}, metadata [[FILE2]], metadata [[FUNC]], i32 15, i32 0, i32 0} ; [ DW_TAG_lexical_block ]
+// CHECK: [[M4]] = metadata !{i32 {{[0-9]*}}, metadata [[FUNC]], metadata [[CTXT]], i32 19} ; [ DW_TAG_imported_module ]
+// CHECK: [[M5]] = metadata !{i32 {{[0-9]*}}, metadata [[FUNC]], metadata [[FOO:![0-9]*]], i32 20} ; [ DW_TAG_imported_declaration ]
+// CHECK: [[FOO]] {{.*}} ; [ DW_TAG_structure_type ] [foo] [line 5, size 0, align 0, offset 0] [fwd] [from ]
+// CHECK: [[M6]] = metadata !{i32 {{[0-9]*}}, metadata [[FUNC]], metadata [[BAR:![0-9]*]], i32 21} ; [ DW_TAG_imported_declaration ]
+// CHECK: [[BAR]] {{.*}} ; [ DW_TAG_structure_type ] [bar] [line 6, {{.*}}] [fwd] [from ]
+// CHECK: [[M7]] = metadata !{i32 {{[0-9]*}}, metadata [[FUNC]], metadata [[F1]], i32 22} ; [ DW_TAG_imported_declaration ]
+// CHECK: [[M8]] = metadata !{i32 {{[0-9]*}}, metadata [[FUNC]], metadata [[I]], i32 23} ; [ DW_TAG_imported_declaration ]
+// CHECK: [[M9]] = metadata !{i32 {{[0-9]*}}, metadata [[FUNC]], metadata [[BAZ:![0-9]*]], i32 24} ; [ DW_TAG_imported_declaration ]
+// CHECK: [[BAZ]] = metadata !{i32 {{[0-9]*}}, metadata [[FOOCPP]], metadata [[NS]], {{.*}} ; [ DW_TAG_typedef ] [baz] {{.*}} [from bar]
+
+// CHECK-GMLT: [[CU:![0-9]*]] = {{.*}}[[MODULES:![0-9]*]], metadata !""} ; [ DW_TAG_compile_unit ]
+// CHECK-GMLT: [[MODULES]] = metadata !{i32 0}
+
+// CHECK-NOLIMIT: ; [ DW_TAG_structure_type ] [bar] [line 6, {{.*}}] [from ]
 
 // FIXME: It is confused on win32 to generate file entry when dosish filename is given.
 // REQUIRES: shell