enable stacktrace-on-assert/abort

also stop hiding the top frame from jl_unw_stepn,
sometimes it's actually useful

Author: vtjnash

src/signal-handling.c

@@ -48,13 +48,13 @@ void jl_critical_error(int sig, bt_context_t *context, uintptr_t *bt_data, size_
     // This function is not allowed to reference any TLS variables.
     // We need to explicitly pass in the TLS buffer pointer when
     // we make `jl_filename` and `jl_lineno` thread local.
-    size_t n = *bt_size;
+    size_t i, n = *bt_size;
     if (sig)
         jl_safe_printf("\nsignal (%d): %s\n", sig, strsignal(sig));
     jl_safe_printf("while loading %s, in expression starting on line %d\n", jl_filename, jl_lineno);
     if (context)
         *bt_size = n = rec_backtrace_ctx(bt_data, JL_MAX_BT_SIZE, context);
-    for(size_t i=0; i < n; i++)
+    for (i = 0; i < n; i++)
         jl_gdblookup(bt_data[i] - 1);
     gc_debug_print_status();
     gc_debug_critical_error();

src/signals-unix.c

@@ -55,14 +55,14 @@ void sigdie_handler(int sig, siginfo_t *info, void *context)
 {
     sigset_t sset;
     uv_tty_reset_mode();
-    sigfillset(&sset);
-    sigprocmask(SIG_UNBLOCK, &sset, NULL);
-    signal(sig, SIG_DFL);
 #ifdef __APPLE__
     jl_critical_error(sig, (bt_context_t*)&((ucontext64_t*)context)->uc_mcontext64->__ss, jl_bt_data, &jl_bt_size);
 #else
     jl_critical_error(sig, (bt_context_t*)context, jl_bt_data, &jl_bt_size);
 #endif
+    sigfillset(&sset);
+    sigprocmask(SIG_UNBLOCK, &sset, NULL);
+    signal(sig, SIG_DFL);
     if (sig != SIGSEGV &&
         sig != SIGBUS &&
         sig != SIGILL) {
@@ -464,6 +464,9 @@ void jl_install_default_signal_handlers(void)
     if (sigaction(SIGILL, &act_die, NULL) < 0) {
         jl_errorf("fatal error: sigaction: %s", strerror(errno));
     }
+    if (sigaction(SIGABRT, &act_die, NULL) < 0) {
+        jl_errorf("fatal error: sigaction: %s", strerror(errno));
+    }
     if (sigaction(SIGSYS, &act_die, NULL) < 0) {
         jl_errorf("fatal error: sigaction: %s", strerror(errno));
     }

src/signals-win.c

@@ -361,6 +361,9 @@ void jl_install_default_signal_handlers(void)
     if (signal(SIGTERM, (void (__cdecl *)(int))crt_sig_handler) == SIG_ERR) {
         jl_error("fatal error: Couldn't set SIGTERM");
     }
+    if (signal(SIGABRT, (void (__cdecl *)(int))crt_sig_handler) == SIG_ERR) {
+        jl_error("fatal error: Couldn't set SIGABRT");
+    }
     SetUnhandledExceptionFilter(exception_handler);
 }
 

src/stackwalk.c

@@ -40,13 +40,14 @@ size_t jl_unw_stepn(bt_cursor_t *cursor, uintptr_t *ip, uintptr_t *sp, size_t ma
 #endif
         while (1) {
            if (n >= maxsize) {
-               n += 1; // return maxsize + 1 if ran out of space
+               n = maxsize; // return maxsize + 1 if ran out of space
                break;
            }
            if (!jl_unw_step(cursor, &ip[n], sp ? &sp[n] : &nullsp))
                break;
            n++;
         }
+        n++;
 #if !defined(_OS_WINDOWS_)
     }
     else {