commit 4da2503d70dc4bc1444454876e3794b69227d90d
author Christopher Ferris <cferris@google.com> Wed Mar 07 13:38:48 2018 -0800
committer Christopher Ferris <cferris@google.com> Mon Apr 02 18:59:23 2018 -0700
tree d904c750ebac96aee76df44baad1320c0db211a3
parent a3f6f6c1b9135c90e410f5382b153db9a43a4db0

Refactor malloc debug.

Changes
- Refactor the code so that only guards require creating a special header
  for every pointer allocated.
- Store only a single copy of every backtrace. This saves memory so that
  turning on the backtrace option doesn't result in 10X memory usage.
- Added new option track_allocs that only verifies pointers are valid for
  free/malloc_usable_size/realloc.
- Remove suffix from test names.
- Add the TRACK_ALLOCS options to all guard options.
- Add new option verify_pointers that is a lightweight way to verify
  pointers that are passed to allocation routines.
- Do auto-formatting of the code.
- Updated documentation for all of these changes.

Bug: 74361929

Test: Ran unit tests.
Test: Ran libmemunreachable unit tests.
Test: Ran an app with backtrace enabled.

Change-Id: I3246c48ae4f9811f64622d90d0a9b4d9d818702c

libc/malloc_debug/backtrace.cpp

diff --git a/libc/malloc_debug/backtrace.cpp b/libc/malloc_debug/backtrace.cpp
index 2443ba1..cd8c334 100644
--- a/libc/malloc_debug/backtrace.cpp
+++ b/libc/malloc_debug/backtrace.cpp
@@ -38,9 +38,9 @@
 
 #include <demangle.h>
 
+#include "MapData.h"
 #include "backtrace.h"
 #include "debug_log.h"
-#include "MapData.h"
 
 #if defined(__LP64__)
 #define PAD_PTR "016" PRIxPTR
@@ -69,8 +69,7 @@
   _Unwind_Backtrace(find_current_map, nullptr);
 }
 
-void backtrace_shutdown() {
-}
+void backtrace_shutdown() {}
 
 struct stack_crawl_state_t {
   uintptr_t* frames;
@@ -165,13 +164,13 @@
 
     char buf[1024];
     if (symbol != nullptr) {
-      async_safe_format_buffer(
-          buf, sizeof(buf), "          #%02zd  pc %" PAD_PTR "  %s%s (%s+%" PRIuPTR ")\n", frame_num,
-          rel_pc, soname, offset_buf, demangle(symbol).c_str(), frames[frame_num] - offset);
+      async_safe_format_buffer(buf, sizeof(buf),
+                               "          #%02zd  pc %" PAD_PTR "  %s%s (%s+%" PRIuPTR ")\n",
+                               frame_num, rel_pc, soname, offset_buf, demangle(symbol).c_str(),
+                               frames[frame_num] - offset);
     } else {
-      async_safe_format_buffer(
-          buf, sizeof(buf), "          #%02zd  pc %" PAD_PTR "  %s%s\n", frame_num, rel_pc, soname,
-          offset_buf);
+      async_safe_format_buffer(buf, sizeof(buf), "          #%02zd  pc %" PAD_PTR "  %s%s\n",
+                               frame_num, rel_pc, soname, offset_buf);
     }
     str += buf;
   }