Add support for displaying soname in an apk.

Changes:
- Change GetSoname to always returns a std::string.
- Added new unit tests for the soname printing.
- Modify the GetElf() function to save the same elf when we see rosegment
  linkers that split the read-only and read-write across a map. This
  avoids creating multiple elf objects for each map.
- Fixed a few offline unwind tests.

Bug: 29218999

Test: Unit tests pass.
Change-Id: Iad7c38b5c2957a8c5fd4ba94ebec335bafcad57d

1 files changed, 6 insertions, 0 deletions

diff --git a/libunwindstack/Unwinder.cpp b/libunwindstack/Unwinder.cpp
index 2734cf8..a1c58dd 100644
--- a/libunwindstack/Unwinder.cpp
+++ b/libunwindstack/Unwinder.cpp
@@ -105,6 +105,12 @@ void Unwinder::FillInFrame(MapInfo* map_info, Elf* elf, uint64_t rel_pc, uint64_
 
   if (resolve_names_) {
     frame->map_name = map_info->name;
+    if (embedded_soname_ && map_info->elf_start_offset != 0 && !frame->map_name.empty()) {
+      std::string soname = elf->GetSoname();
+      if (!soname.empty()) {
+        frame->map_name += '!' + soname;
+      }
+    }
   }
   frame->map_elf_start_offset = map_info->elf_start_offset;
   frame->map_exact_offset = map_info->offset;