libbacktrace: expose libunwindstack Unwind routine.

Test: backtrace_test32/64 on hikey960
Change-Id: Iae6e342a8ffd13b4d5f76b39dd434c827f7a4d9e

2 files changed, 11 insertions, 4 deletions

diff --git a/libbacktrace/UnwindStack.cpp b/libbacktrace/UnwindStack.cpp
index 41153ce19..0f6730c8b 100644
--- a/libbacktrace/UnwindStack.cpp
+++ b/libbacktrace/UnwindStack.cpp
@@ -66,8 +66,8 @@ static std::string GetFunctionName(BacktraceMap* back_map, uintptr_t pc, uintptr
   return name;
 }
 
-static bool Unwind(unwindstack::Regs* regs, BacktraceMap* back_map,
-                   std::vector<backtrace_frame_data_t>* frames, size_t num_ignore_frames) {
+bool Backtrace::Unwind(unwindstack::Regs* regs, BacktraceMap* back_map,
+                       std::vector<backtrace_frame_data_t>* frames, size_t num_ignore_frames) {
   static std::set<std::string> skip_names{"libunwindstack.so", "libbacktrace.so"};
   UnwindStackMap* stack_map = reinterpret_cast<UnwindStackMap*>(back_map);
   auto process_memory = stack_map->process_memory();
@@ -127,7 +127,7 @@ bool UnwindStackCurrent::UnwindFromContext(size_t num_ignore_frames, ucontext_t*
   }
 
   error_ = BACKTRACE_UNWIND_NO_ERROR;
-  return ::Unwind(regs.get(), GetMap(), &frames_, num_ignore_frames);
+  return Backtrace::Unwind(regs.get(), GetMap(), &frames_, num_ignore_frames);
 }
 
 UnwindStackPtrace::UnwindStackPtrace(pid_t pid, pid_t tid, BacktraceMap* map)
@@ -147,7 +147,7 @@ bool UnwindStackPtrace::Unwind(size_t num_ignore_frames, ucontext_t* context) {
   }
 
   error_ = BACKTRACE_UNWIND_NO_ERROR;
-  return ::Unwind(regs.get(), GetMap(), &frames_, num_ignore_frames);
+  return Backtrace::Unwind(regs.get(), GetMap(), &frames_, num_ignore_frames);
 }
 
 Backtrace* Backtrace::CreateNew(pid_t pid, pid_t tid, BacktraceMap* map) {
diff --git a/libbacktrace/include/backtrace/Backtrace.h b/libbacktrace/include/backtrace/Backtrace.h
index 289fd0cef..274c64bb6 100644
--- a/libbacktrace/include/backtrace/Backtrace.h
+++ b/libbacktrace/include/backtrace/Backtrace.h
@@ -77,6 +77,10 @@ struct backtrace_stackinfo_t {
   const uint8_t* data;
 };
 
+namespace unwindstack {
+class Regs;
+}
+
 class Backtrace {
 public:
   // Create the correct Backtrace object based on what is to be unwound.
@@ -106,6 +110,9 @@ public:
   // Get the current stack trace and store in the backtrace_ structure.
   virtual bool Unwind(size_t num_ignore_frames, ucontext_t* context = NULL) = 0;
 
+  static bool Unwind(unwindstack::Regs* regs, BacktraceMap* back_map,
+                     std::vector<backtrace_frame_data_t>* frames, size_t num_ignore_frames);
+
   // Get the function name and offset into the function given the pc.
   // If the string is empty, then no valid function name was found,
   // or the pc is not in any valid map.