Add better free tracking.

Included in this change:

- Change the tag when a pointer is freed so it's easy to detect if
  an already freed pointer is being used.
- Move the free backtrace out of the header. This backtrace is only
  used under only some circumstances, so no need to allocate space
  in all headers for it.
- Add new option free_track_backtrace_num_frames to specify how many
  frames to record when the free occurs. This removes the dependency
  on the backtrace option to get backtraces.

Bug: 26739265
Change-Id: I76f5209507dcf46af67ada162a7cb2bf282116f2

1 files changed, 1 insertions, 1 deletions

diff --git a/libc/malloc_debug/tests/backtrace_fake.cpp b/libc/malloc_debug/tests/backtrace_fake.cpp
index 32da696bb..db542e5e2 100644
--- a/libc/malloc_debug/tests/backtrace_fake.cpp
+++ b/libc/malloc_debug/tests/backtrace_fake.cpp
@@ -52,7 +52,7 @@ size_t backtrace_get(uintptr_t* frames, size_t frame_num) {
   return total_frames;
 }
 
-void backtrace_log(uintptr_t* frames, size_t frame_count) {
+void backtrace_log(const uintptr_t* frames, size_t frame_count) {
   for (size_t i = 0; i < frame_count; i++) {
     error_log("  #%02zd pc %p", i, reinterpret_cast<void*>(frames[i]));
   }