From 46756821c4fe238f12a6e5ea18c356398f8d8795 Mon Sep 17 00:00:00 2001
From: Christopher Ferris <cferris@google.com>
Date: Tue, 14 Jan 2014 20:16:30 -0800
Subject: Rewrite libbacktrace to be all C++.

This includes removing the map_info.c source and replacing it with the
BacktraceMap class to handle all map related code.

Change all callers of libbacktrace map functionality.

Also modify the corkscrew thread code so that it doesn't need to build
the map twice (once in the corkscrew format and once in the libbacktrace
format).

Change-Id: I32865a39f83a3dd6f958fc03c2759ba47d12382e
---
 libbacktrace/UnwindPtrace.cpp | 40 ++++++++++++++--------------------------
 1 file changed, 14 insertions(+), 26 deletions(-)

(limited to 'libbacktrace/UnwindPtrace.cpp')

diff --git a/libbacktrace/UnwindPtrace.cpp b/libbacktrace/UnwindPtrace.cpp
index 6fecb76..e45c5f8 100644
--- a/libbacktrace/UnwindPtrace.cpp
+++ b/libbacktrace/UnwindPtrace.cpp
@@ -16,13 +16,12 @@
 
 #define LOG_TAG "libbacktrace"
 
-#include <backtrace/backtrace.h>
+#include <backtrace/Backtrace.h>
+#include <backtrace/BacktraceMap.h>
 
 #include <sys/types.h>
 #include <string.h>
 
-#include <cutils/log.h>
-
 #include <libunwind.h>
 #include <libunwind-ptrace.h>
 
@@ -55,9 +54,6 @@ bool UnwindPtrace::Unwind(size_t num_ignore_frames) {
     return false;
   }
 
-  backtrace_t* backtrace = GetBacktraceData();
-  backtrace->num_frames = 0;
-
   unw_cursor_t cursor;
   int ret = unw_init_remote(&cursor, addr_space_, upt_info_);
   if (ret < 0) {
@@ -65,6 +61,9 @@ bool UnwindPtrace::Unwind(size_t num_ignore_frames) {
     return false;
   }
 
+  std::vector<backtrace_frame_data_t>* frames = GetFrames();
+  frames->reserve(MAX_BACKTRACE_FRAMES);
+  size_t num_frames = 0;
   do {
     unw_word_t pc;
     ret = unw_get_reg(&cursor, UNW_REG_IP, &pc);
@@ -80,39 +79,28 @@ bool UnwindPtrace::Unwind(size_t num_ignore_frames) {
     }
 
     if (num_ignore_frames == 0) {
-      size_t num_frames = backtrace->num_frames;
-      backtrace_frame_data_t* frame = &backtrace->frames[num_frames];
+      frames->resize(num_frames+1);
+      backtrace_frame_data_t* frame = &frames->at(num_frames);
       frame->num = num_frames;
       frame->pc = static_cast<uintptr_t>(pc);
       frame->sp = static_cast<uintptr_t>(sp);
       frame->stack_size = 0;
-      frame->map_name = NULL;
-      frame->map_offset = 0;
-      frame->func_name = NULL;
-      frame->func_offset = 0;
 
       if (num_frames > 0) {
-        backtrace_frame_data_t* prev = &backtrace->frames[num_frames-1];
+        backtrace_frame_data_t* prev = &frames->at(num_frames-1);
         prev->stack_size = frame->sp - prev->sp;
       }
 
-      std::string func_name = backtrace_obj_->GetFunctionName(frame->pc, &frame->func_offset);
-      if (!func_name.empty()) {
-        frame->func_name = strdup(func_name.c_str());
-      }
+      frame->func_name = backtrace_obj_->GetFunctionName(frame->pc, &frame->func_offset);
 
-      uintptr_t map_start;
-      frame->map_name = backtrace_obj_->GetMapName(frame->pc, &map_start);
-      if (frame->map_name) {
-        frame->map_offset = frame->pc - map_start;
-      }
+      frame->map = backtrace_obj_->FindMap(frame->pc);
 
-      backtrace->num_frames++;
+      num_frames++;
     } else {
       num_ignore_frames--;
     }
     ret = unw_step (&cursor);
-  } while (ret > 0 && backtrace->num_frames < MAX_BACKTRACE_FRAMES);
+  } while (ret > 0 && num_frames < MAX_BACKTRACE_FRAMES);
 
   return true;
 }
@@ -132,6 +120,6 @@ std::string UnwindPtrace::GetFunctionNameRaw(uintptr_t pc, uintptr_t* offset) {
 //-------------------------------------------------------------------------
 // C++ object creation function.
 //-------------------------------------------------------------------------
-Backtrace* CreatePtraceObj(pid_t pid, pid_t tid, backtrace_map_info_t* map_info) {
-  return new BacktracePtrace(new UnwindPtrace(), pid, tid, map_info);
+Backtrace* CreatePtraceObj(pid_t pid, pid_t tid, BacktraceMap* map) {
+  return new BacktracePtrace(new UnwindPtrace(), pid, tid, map);
 }
-- 
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