This patch adds a new Clang compiler flag "-gline-tables-only".

It reduces the amount of emitted debug information:
1) DIEs in .debug_info have types DW_TAG_compile_unit, DW_TAG_subprogram,
DW_TAG_inlined_subroutine (for opt builds) and DW_TAG_lexical_block only.
2) .debug_str contains only function names.
3) No debug data for types/namespaces/variables is emitted.
4) The data in .debug_line is enough to produce valid stack traces with
function names and line numbers.

Reviewed by Eric Christopher.

llvm-svn: 156160

1 files changed, 33 insertions, 0 deletions

diff --git a/clang/test/CodeGen/debug-info-gline-tables-only.c b/clang/test/CodeGen/debug-info-gline-tables-only.c
new file mode 100644
index 00000000000..067d8e77218
--- /dev/null
+++ b/clang/test/CodeGen/debug-info-gline-tables-only.c
@@ -0,0 +1,33 @@
+// RUN: %clang_cc1 %s -gline-tables-only -S -emit-llvm -o - | FileCheck %s
+// Checks that clang with "-gline-tables-only" doesn't emit debug info
+// for variables and types.
+
+// CHECK-NOT: DW_TAG_variable
+int global = 42;
+
+// CHECK-NOT: DW_TAG_typedef
+// CHECK-NOT: DW_TAG_const_type
+// CHECK-NOT: DW_TAG_pointer_type
+// CHECK-NOT: DW_TAG_array_type
+typedef const char* constCharPtrArray[10];
+
+// CHECK-NOT: DW_TAG_structure_type
+struct S {
+  // CHECK-NOT: DW_TAG_member
+  char a;
+  double b;
+  constCharPtrArray c;
+};
+
+// CHECK-NOT: DW_TAG_enumerator
+// CHECK-NOT: DW_TAG_enumeration_type
+enum E { ZERO = 0, ONE = 1 };
+
+// CHECK-NOT: DW_TAG_arg_variable
+int sum(int p, int q) {
+  // CHECK-NOT: DW_TAG_auto_variable
+  int r = p + q;
+  struct S s;
+  enum E e;
+  return r;
+}