Extract Backtrace out of SafePtr as a general utility

src/backtrace.cc

@@ -1,32 +1,29 @@
-#include "safe_ptr.hh"
-
-#ifdef SAFE_PTR_TRACK_CALLSTACKS
+#include "backtrace.hh"
 
 #include <string.h>
+#include <stdlib.h>
 
-#if defined(__linux__)
+#if defined(__linux__) || defined(__APPLE__)
 # include <execinfo.h>
 #elif defined(__CYGWIN__)
 # include <windows.h>
 #endif
 
-
 namespace Kakoune
 {
 
-
-SafeCountable::Backtrace::Backtrace()
+Backtrace::Backtrace()
 {
-    #if defined(__linux__)
+    #if defined(__linux__) || defined(__APPLE__)
     num_frames = backtrace(stackframes, max_frames);
     #elif defined(__CYGWIN__)
     num_frames = CaptureStackBackTrace(0, max_frames, stackframes, nullptr);
     #endif
 }
 
-const char* SafeCountable::Backtrace::desc() const
+const char* Backtrace::desc() const
 {
-    #if defined(__linux__)
+    #if defined(__linux__) || defined(__APPLE__)
     char** symbols = backtrace_symbols(stackframes, num_frames);
     int size = 0;
     for (int i = 0; i < num_frames; ++i)
@@ -57,4 +54,3 @@ const char* SafeCountable::Backtrace::desc() const
 }
 
 }
-#endif

src/backtrace.hh

@@ -0,0 +1,20 @@
+#ifndef backtrace_hh_INCLUDED
+#define backtrace_hh_INCLUDED
+
+namespace Kakoune
+{
+
+struct Backtrace
+{
+    static constexpr int max_frames = 16;
+    void* stackframes[max_frames];
+    int num_frames = 0;
+
+    Backtrace();
+    const char* desc() const;
+};
+
+}
+
+#endif // backtrace_hh_INCLUDED
+

src/safe_ptr.hh

@@ -5,6 +5,7 @@
 
 #include "assert.hh"
 #include "ref_ptr.hh"
+#include "backtrace.hh"
 
 #include <type_traits>
 #include <utility>
@@ -64,16 +65,6 @@ public:
 
 private:
     #ifdef SAFE_PTR_TRACK_CALLSTACKS
-    struct Backtrace
-    {
-        static constexpr int max_frames = 16;
-        void* stackframes[max_frames];
-        int num_frames = 0;
-
-        Backtrace();
-        const char* desc() const;
-    };
-
     struct Callstack
     {
         Callstack(void* p) : ptr(p) {}