debug/crash: temporarily disable backtrace reporting

We're using breakpad for a few projects. It has much better
functionality.

backtrace_win32.cpp

@@ -46,7 +46,8 @@ backtrace::backtrace (void)
 
 ///////////////////////////////////////////////////////////////////////////////
 std::ostream&
-debug::operator <<(std::ostream &os, ::cruft::backtrace const &rhs) {
+debug::operator <<(std::ostream &os, ::cruft::backtrace const &rhs)
+{
     static auto process = GetCurrentProcess ();
     CHECK (ready);
 

debug/crash_posix.cpp

@@ -53,6 +53,9 @@ void dumping_handler (int sig, siginfo_t *info, void *ucontext)
 void
 cruft::debug::init_crash_handler ()
 {
+    // Keep this disabled for the time being as most projects we're using
+    // employ breakpad which has better functionality.
+#if 0
     struct sigaction new_handler {};
     memset (&new_handler, 0, sizeof (new_handler));
     new_handler.sa_flags = SA_SIGINFO;
@@ -67,4 +70,5 @@ cruft::debug::init_crash_handler ()
             )
         );
     }
+#endif
 }

debug/crash_win32.cpp

@@ -8,9 +8,37 @@
 
 #include "crash.hpp"
 
+#include "assert.hpp"
+
+#include "../backtrace.hpp"
+#include "../win32/windows.hpp"
+
+#include <iostream>
+
+
+///////////////////////////////////////////////////////////////////////////////
+static LPTOP_LEVEL_EXCEPTION_FILTER previous_handler;
+
+
+///////////////////////////////////////////////////////////////////////////////
+static LONG __stdcall
+backtrace_handler (EXCEPTION_POINTERS *data)
+{
+    std::clog << cruft::backtrace () << '\n';
+
+    if (previous_handler)
+        return previous_handler (data);
+    else
+        return EXCEPTION_CONTINUE_SEARCH;
+}
+
+
 ///////////////////////////////////////////////////////////////////////////////
 void
 cruft::debug::init_crash_handler (void)
 {
-
+#if 0
+    CHECK (!previous_handler);
+    previous_handler = SetUnhandledExceptionFilter (backtrace_handler);
+#endif
 }