libunwindstack: expose UnwindStackMap::GetFunctionName.

Test: mma
Change-Id: I8736ff5c2ed7c5e64eb68df5f4eccfed614612c7

4 files changed, 28 insertions, 24 deletions

diff --git a/libbacktrace/UnwindStack.cpp b/libbacktrace/UnwindStack.cpp
index 0f6730c8b..dcd3d09cf 100644
--- a/libbacktrace/UnwindStack.cpp
+++ b/libbacktrace/UnwindStack.cpp
@@ -44,28 +44,6 @@
 #include "UnwindStack.h"
 #include "UnwindStackMap.h"
 
-static std::string GetFunctionName(BacktraceMap* back_map, uintptr_t pc, uintptr_t* offset) {
-  *offset = 0;
-  unwindstack::Maps* maps = reinterpret_cast<UnwindStackMap*>(back_map)->stack_maps();
-
-  // Get the map for this
-  unwindstack::MapInfo* map_info = maps->Find(pc);
-  if (map_info == nullptr || map_info->flags & PROT_DEVICE_MAP) {
-    return "";
-  }
-
-  UnwindStackMap* stack_map = reinterpret_cast<UnwindStackMap*>(back_map);
-  unwindstack::Elf* elf = map_info->GetElf(stack_map->process_memory(), true);
-
-  std::string name;
-  uint64_t func_offset;
-  if (!elf->GetFunctionName(elf->GetRelPc(pc, map_info), &name, &func_offset)) {
-    return "";
-  }
-  *offset = func_offset;
-  return name;
-}
-
 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"};
@@ -111,7 +89,7 @@ UnwindStackCurrent::UnwindStackCurrent(pid_t pid, pid_t tid, BacktraceMap* map)
     : BacktraceCurrent(pid, tid, map) {}
 
 std::string UnwindStackCurrent::GetFunctionNameRaw(uintptr_t pc, uintptr_t* offset) {
-  return ::GetFunctionName(GetMap(), pc, offset);
+  return GetMap()->GetFunctionName(pc, offset);
 }
 
 bool UnwindStackCurrent::UnwindFromContext(size_t num_ignore_frames, ucontext_t* ucontext) {
@@ -134,7 +112,7 @@ UnwindStackPtrace::UnwindStackPtrace(pid_t pid, pid_t tid, BacktraceMap* map)
     : BacktracePtrace(pid, tid, map) {}
 
 std::string UnwindStackPtrace::GetFunctionNameRaw(uintptr_t pc, uintptr_t* offset) {
-  return ::GetFunctionName(GetMap(), pc, offset);
+  return GetMap()->GetFunctionName(pc, offset);
 }
 
 bool UnwindStackPtrace::Unwind(size_t num_ignore_frames, ucontext_t* context) {
diff --git a/libbacktrace/UnwindStackMap.cpp b/libbacktrace/UnwindStackMap.cpp
index d4a2444dc..a9121a800 100644
--- a/libbacktrace/UnwindStackMap.cpp
+++ b/libbacktrace/UnwindStackMap.cpp
@@ -75,6 +75,27 @@ void UnwindStackMap::FillIn(uintptr_t addr, backtrace_map_t* map) {
   map->load_bias = elf->GetLoadBias();
 }
 
+std::string UnwindStackMap::GetFunctionName(uintptr_t pc, uintptr_t* offset) {
+  *offset = 0;
+  unwindstack::Maps* maps = stack_maps();
+
+  // Get the map for this
+  unwindstack::MapInfo* map_info = maps->Find(pc);
+  if (map_info == nullptr || map_info->flags & PROT_DEVICE_MAP) {
+    return "";
+  }
+
+  unwindstack::Elf* elf = map_info->GetElf(process_memory(), true);
+
+  std::string name;
+  uint64_t func_offset;
+  if (!elf->GetFunctionName(elf->GetRelPc(pc, map_info), &name, &func_offset)) {
+    return "";
+  }
+  *offset = func_offset;
+  return name;
+}
+
 //-------------------------------------------------------------------------
 // BacktraceMap create function.
 //-------------------------------------------------------------------------
diff --git a/libbacktrace/UnwindStackMap.h b/libbacktrace/UnwindStackMap.h
index b93b3403c..2a8af839d 100644
--- a/libbacktrace/UnwindStackMap.h
+++ b/libbacktrace/UnwindStackMap.h
@@ -34,6 +34,8 @@ class UnwindStackMap : public BacktraceMap {
 
   void FillIn(uintptr_t addr, backtrace_map_t* map) override;
 
+  virtual std::string GetFunctionName(uintptr_t pc, uintptr_t* offset) override;
+
   unwindstack::Maps* stack_maps() { return stack_maps_.get(); }
 
   const std::shared_ptr<unwindstack::Memory>& process_memory() { return process_memory_; }
diff --git a/libbacktrace/include/backtrace/BacktraceMap.h b/libbacktrace/include/backtrace/BacktraceMap.h
index 6cf8b3fca..104479d71 100644
--- a/libbacktrace/include/backtrace/BacktraceMap.h
+++ b/libbacktrace/include/backtrace/BacktraceMap.h
@@ -62,6 +62,9 @@ public:
   // Fill in the map data structure for the given address.
   virtual void FillIn(uintptr_t addr, backtrace_map_t* map);
 
+  // Only supported with the new unwinder.
+  virtual std::string GetFunctionName(uintptr_t /*pc*/, uintptr_t* /*offset*/) { return ""; }
+
   // The flags returned are the same flags as used by the mmap call.
   // The values are PROT_*.
   int GetFlags(uintptr_t pc) {