Fix issues in libunwindstack.

- Add a load_bias field in MapInfo so that it can be loaded offline,
  and also so it can be cached.
- Add an Add function to the Maps class so that it's possible to manually
  create a map.
- Remove the OfflineMaps class since I haven't found a reason for this to
  exist.
- Add a pointer to the gnu debugdata compressed section in the interface
  itself and modify the step path to try eh_frame, then debug_frame, then
  gnu_debugdata. This way arm can add exidx as the last step behind
  gnu_debugdata. Add an offline test to verify the order of unwind.
- Fix x86_64_ucontext_t since it was a different size on 32 bit and 64 bit
  systems.

Test: Pass new unit tests.
Change-Id: I978b70d6c244bd307c62a29886d24c1a8cb2af23

1 files changed, 6 insertions, 1 deletions

diff --git a/libunwindstack/include/unwindstack/ElfInterface.h b/libunwindstack/include/unwindstack/ElfInterface.h
index 5cfe74d..5d3cd5e 100644
--- a/libunwindstack/include/unwindstack/ElfInterface.h
+++ b/libunwindstack/include/unwindstack/ElfInterface.h
@@ -60,7 +60,8 @@ class ElfInterface {
   virtual bool GetFunctionName(uint64_t addr, uint64_t load_bias, std::string* name,
                                uint64_t* offset) = 0;
 
-  virtual bool Step(uint64_t rel_pc, Regs* regs, Memory* process_memory, bool* finished);
+  virtual bool Step(uint64_t rel_pc, uint64_t load_bias, Regs* regs, Memory* process_memory,
+                    bool* finished);
 
   Memory* CreateGnuDebugdataMemory();
 
@@ -68,6 +69,8 @@ class ElfInterface {
 
   const std::unordered_map<uint64_t, LoadInfo>& pt_loads() { return pt_loads_; }
 
+  void SetGnuDebugdataInterface(ElfInterface* interface) { gnu_debugdata_interface_ = interface; }
+
   uint64_t dynamic_offset() { return dynamic_offset_; }
   uint64_t dynamic_size() { return dynamic_size_; }
   uint64_t eh_frame_hdr_offset() { return eh_frame_hdr_offset_; }
@@ -134,6 +137,8 @@ class ElfInterface {
 
   std::unique_ptr<DwarfSection> eh_frame_;
   std::unique_ptr<DwarfSection> debug_frame_;
+  // The Elf object owns the gnu_debugdata interface object.
+  ElfInterface* gnu_debugdata_interface_ = nullptr;
 
   std::vector<Symbols*> symbols_;
 };