Add ability to read jit gdb data.

Changes:
- New JitDebug class to handle all of the jit gdb interface.
- Add unit tests for all, along with new offline test using debug data.
- Add new Memory type called MemoryOfflineParts that has multiple
  MemoryOffline objects to support the offline test.
- Update the tools to use the JitDebug object.
- Modify libbacktrace to use the JitDebug, but only looking in libart.so
  and libartd.so.
- Change the Format32Bits to Is32Bit since it's more accurate and I use
  it in a different context where original name didn't make sense.
- Add a new function to find global variables in an elf file
  (GetGlobalVariable).
- Add a new function to determine if a pc is valid for this elf (IsValidPc).

Bug: 68396769

Test: Ran new unit tests. Added new offline test that uses jit debug data.
Test: Ran art test that generates jit data and verified a crash unwinds
Test: through the jit data.
Change-Id: I6e7ee2f5bab2242028a06feece156dff21c0a974

3 files changed, 12 insertions, 0 deletions

diff --git a/libbacktrace/UnwindStack.cpp b/libbacktrace/UnwindStack.cpp
index 2a555afc4..b0345a140 100644
--- a/libbacktrace/UnwindStack.cpp
+++ b/libbacktrace/UnwindStack.cpp
@@ -50,6 +50,7 @@ bool Backtrace::Unwind(unwindstack::Regs* regs, BacktraceMap* back_map,
   auto process_memory = stack_map->process_memory();
   unwindstack::Unwinder unwinder(MAX_BACKTRACE_FRAMES + num_ignore_frames, stack_map->stack_maps(),
                                  regs, stack_map->process_memory());
+  unwinder.SetJitDebug(stack_map->GetJitDebug(), regs->Arch());
   unwinder.Unwind(skip_names, &stack_map->GetSuffixesToIgnore());
 
   if (num_ignore_frames >= unwinder.NumFrames()) {
diff --git a/libbacktrace/UnwindStackMap.cpp b/libbacktrace/UnwindStackMap.cpp
index 836a774b9..93406dc62 100644
--- a/libbacktrace/UnwindStackMap.cpp
+++ b/libbacktrace/UnwindStackMap.cpp
@@ -18,6 +18,9 @@
 #include <stdlib.h>
 #include <sys/types.h>
 
+#include <string>
+#include <vector>
+
 #include <backtrace/BacktraceMap.h>
 #include <unwindstack/Elf.h>
 #include <unwindstack/MapInfo.h>
@@ -39,6 +42,10 @@ bool UnwindStackMap::Build() {
   // Create the process memory object.
   process_memory_ = unwindstack::Memory::CreateProcessMemory(pid_);
 
+  // Create a JitDebug object for getting jit unwind information.
+  std::vector<std::string> search_libs_{"libart.so", "libartd.so"};
+  jit_debug_.reset(new unwindstack::JitDebug(process_memory_, search_libs_));
+
   if (!stack_maps_->Parse()) {
     return false;
   }
diff --git a/libbacktrace/UnwindStackMap.h b/libbacktrace/UnwindStackMap.h
index 2f63655fd..12c590982 100644
--- a/libbacktrace/UnwindStackMap.h
+++ b/libbacktrace/UnwindStackMap.h
@@ -23,6 +23,7 @@
 #include <memory>
 
 #include <backtrace/BacktraceMap.h>
+#include <unwindstack/JitDebug.h>
 #include <unwindstack/Maps.h>
 
 class UnwindStackMap : public BacktraceMap {
@@ -41,11 +42,14 @@ class UnwindStackMap : public BacktraceMap {
 
   const std::shared_ptr<unwindstack::Memory>& process_memory() { return process_memory_; }
 
+  unwindstack::JitDebug* GetJitDebug() { return jit_debug_.get(); }
+
  protected:
   uint64_t GetLoadBias(size_t index) override;
 
   std::unique_ptr<unwindstack::Maps> stack_maps_;
   std::shared_ptr<unwindstack::Memory> process_memory_;
+  std::unique_ptr<unwindstack::JitDebug> jit_debug_;
 };
 
 #endif  // _LIBBACKTRACE_UNWINDSTACK_MAP_H