RAI: Prepend signal number and thread ID on backtraces

Prepend `[signal (X) ]thread (Y) ` to each backtrace line that is
displayed.

Co-authored-by: Diogo Netto <61364108+d-netto@users.noreply.github.com>

src/julia_internal.h

@@ -1451,8 +1451,8 @@ JL_DLLEXPORT jl_value_t *jl_get_backtrace(void);
 void jl_critical_error(int sig, int si_code, bt_context_t *context, jl_task_t *ct);
 JL_DLLEXPORT void jl_raise_debugger(void) JL_NOTSAFEPOINT;
 JL_DLLEXPORT void jl_gdblookup(void* ip) JL_NOTSAFEPOINT;
-void jl_print_native_codeloc(uintptr_t ip) JL_NOTSAFEPOINT;
-void jl_print_bt_entry_codeloc(jl_bt_element_t *bt_data) JL_NOTSAFEPOINT;
+void jl_print_native_codeloc(char *pre_str, uintptr_t ip) JL_NOTSAFEPOINT;
+void jl_print_bt_entry_codeloc(int sig, jl_bt_element_t *bt_data) JL_NOTSAFEPOINT;
 #ifdef _OS_WINDOWS_
 JL_DLLEXPORT void jl_refresh_dbg_module_list(void);
 #endif

src/safepoint.c

@@ -172,7 +172,7 @@ void jl_gc_wait_for_the_world(jl_ptls_t* gc_all_tls_states, int gc_n_threads)
                         size_t bt_size = jl_try_record_thread_backtrace(ptls2, ptls->bt_data, JL_MAX_BT_SIZE);
                         // Print the backtrace of the straggler
                         for (size_t i = 0; i < bt_size; i += jl_bt_entry_size(ptls->bt_data + i)) {
-                            jl_print_bt_entry_codeloc(ptls->bt_data + i);
+                            jl_print_bt_entry_codeloc(-1, ptls->bt_data + i);
                         }
                     }
                 }

src/signal-handling.c

@@ -615,7 +615,7 @@ void jl_critical_error(int sig, int si_code, bt_context_t *context, jl_task_t *c
         *bt_size = n = rec_backtrace_ctx(bt_data, JL_MAX_BT_SIZE, context, NULL);
     }
     for (i = 0; i < n; i += jl_bt_entry_size(bt_data + i)) {
-        jl_print_bt_entry_codeloc(bt_data + i);
+        jl_print_bt_entry_codeloc(sig, bt_data + i);
     }
     jl_gc_debug_print_status();
     jl_gc_debug_critical_error();

src/signals-unix.c

@@ -1082,7 +1082,7 @@ static void *signal_listener(void *arg)
             jl_safe_printf("\nsignal (%d): %s\n", sig, strsignal(sig));
             size_t i;
             for (i = 0; i < signal_bt_size; i += jl_bt_entry_size(signal_bt_data + i)) {
-                jl_print_bt_entry_codeloc(signal_bt_data + i);
+                jl_print_bt_entry_codeloc(-1, signal_bt_data + i);
             }
         }
     }

src/signals-win.c

@@ -333,7 +333,7 @@ LONG WINAPI jl_exception_handler(struct _EXCEPTION_POINTERS *ExceptionInfo)
         jl_safe_printf("UNKNOWN"); break;
     }
     jl_safe_printf(" at 0x%zx -- ", (size_t)ExceptionInfo->ExceptionRecord->ExceptionAddress);
-    jl_print_native_codeloc((uintptr_t)ExceptionInfo->ExceptionRecord->ExceptionAddress);
+    jl_print_native_codeloc("", (uintptr_t)ExceptionInfo->ExceptionRecord->ExceptionAddress);
 
     jl_critical_error(0, 0, ExceptionInfo->ContextRecord, ct);
     static int recursion = 0;

src/stackwalk.c

@@ -633,22 +633,25 @@ JL_DLLEXPORT jl_value_t *jl_lookup_code_address(void *ip, int skipC)
     return rs;
 }
 
-static void jl_safe_print_codeloc(const char* func_name, const char* file_name,
+static void jl_safe_print_codeloc(const char *pre_str,
+                                  const char* func_name, const char* file_name,
                                   int line, int inlined) JL_NOTSAFEPOINT
 {
     const char *inlined_str = inlined ? " [inlined]" : "";
     if (line != -1) {
-        jl_safe_printf("%s at %s:%d%s\n", func_name, file_name, line, inlined_str);
+        jl_safe_printf("%s%s at %s:%d%s\n",
+                       pre_str, func_name, file_name, line, inlined_str);
     }
     else {
-        jl_safe_printf("%s at %s (unknown line)%s\n", func_name, file_name, inlined_str);
+        jl_safe_printf("%s%s at %s (unknown line)%s\n",
+                       pre_str, func_name, file_name, inlined_str);
     }
 }
 
 // Print function, file and line containing native instruction pointer `ip` by
 // looking up debug info. Prints multiple such frames when `ip` points to
 // inlined code.
-void jl_print_native_codeloc(uintptr_t ip) JL_NOTSAFEPOINT
+void jl_print_native_codeloc(char *pre_str, uintptr_t ip) JL_NOTSAFEPOINT
 {
     // This function is not allowed to reference any TLS variables since
     // it can be called from an unmanaged thread on OSX.
@@ -660,10 +663,11 @@ void jl_print_native_codeloc(uintptr_t ip) JL_NOTSAFEPOINT
     for (i = 0; i < n; i++) {
         jl_frame_t frame = frames[i];
         if (!frame.func_name) {
-            jl_safe_printf("unknown function (ip: %p) at %s\n", (void*)ip, frame.file_name ? frame.file_name : "(unknown file)");
+            jl_safe_printf("%sunknown function (ip: %p) at %s\n", pre_str, (void*)ip, frame.file_name ? frame.file_name : "(unknown file)");
         }
         else {
-            jl_safe_print_codeloc(frame.func_name, frame.file_name, frame.line, frame.inlined);
+            jl_safe_print_codeloc(pre_str, frame.func_name,
+                                  frame.file_name, frame.line, frame.inlined);
             free(frame.func_name);
         }
         free(frame.file_name);
@@ -721,7 +725,7 @@ const char *jl_debuginfo_name(jl_value_t *func)
 
 // func == module : top-level
 // func == NULL : macro expansion
-static void jl_print_debugloc(jl_debuginfo_t *debuginfo, jl_value_t *func, size_t ip, int inlined) JL_NOTSAFEPOINT
+static void jl_print_debugloc(const char *pre_str, jl_debuginfo_t *debuginfo, jl_value_t *func, size_t ip, int inlined) JL_NOTSAFEPOINT
 {
     if (!jl_is_symbol(debuginfo->def)) // this is a path or
         func = debuginfo->def; // this is inlined code
@@ -730,26 +734,33 @@ static void jl_print_debugloc(jl_debuginfo_t *debuginfo, jl_value_t *func, size_
     if (edges_idx) {
         jl_debuginfo_t *edge = (jl_debuginfo_t*)jl_svecref(debuginfo->edges, edges_idx - 1);
         assert(jl_typetagis(edge, jl_debuginfo_type));
-        jl_print_debugloc(edge, NULL, stmt.pc, 1);
+        jl_print_debugloc(pre_str, edge, NULL, stmt.pc, 1);
     }
     intptr_t ip2 = stmt.line;
     if (ip2 >= 0 && ip > 0 && (jl_value_t*)debuginfo->linetable != jl_nothing) {
-        jl_print_debugloc(debuginfo->linetable, func, ip2, 0);
+        jl_print_debugloc(pre_str, debuginfo->linetable, func, ip2, 0);
     }
     else {
         if (ip2 < 0) // set broken debug info to ignored
             ip2 = 0;
         const char *func_name = jl_debuginfo_name(func);
         const char *file = jl_debuginfo_file(debuginfo);
-        jl_safe_print_codeloc(func_name, file, ip2, inlined);
+        jl_safe_print_codeloc(pre_str, func_name, file, ip2, inlined);
     }
 }
 
 // Print code location for backtrace buffer entry at *bt_entry
-void jl_print_bt_entry_codeloc(jl_bt_element_t *bt_entry) JL_NOTSAFEPOINT
+void jl_print_bt_entry_codeloc(int sig, jl_bt_element_t *bt_entry) JL_NOTSAFEPOINT
 {
+    char sig_str[32], pre_str[64];
+    sig_str[0] = '\0';
+    if (sig != -1) {
+        snprintf(sig_str, 32, "signal (%d) ", sig);
+    }
+    snprintf(pre_str, 64, "%sthread (%d) ", sig_str, jl_threadid() + 1);
+
     if (jl_bt_is_native(bt_entry)) {
-        jl_print_native_codeloc(bt_entry[0].uintptr);
+        jl_print_native_codeloc(pre_str, bt_entry[0].uintptr);
     }
     else if (jl_bt_entry_tag(bt_entry) == JL_BT_INTERP_FRAME_TAG) {
         size_t ip = jl_bt_entry_header(bt_entry); // zero-indexed
@@ -768,7 +779,7 @@ void jl_print_bt_entry_codeloc(jl_bt_element_t *bt_entry) JL_NOTSAFEPOINT
         if (jl_is_code_info(code)) {
             jl_code_info_t *src = (jl_code_info_t*)code;
             // See also the debug info handling in codegen.cpp.
-            jl_print_debugloc(src->debuginfo, def, ip + 1, 0);
+            jl_print_debugloc(pre_str, src->debuginfo, def, ip + 1, 0);
         }
         else {
             // If we're using this function something bad has already happened;
@@ -1357,7 +1368,9 @@ JL_DLLEXPORT jl_record_backtrace_result_t jl_record_backtrace(jl_task_t *t, jl_b
 
 JL_DLLEXPORT void jl_gdblookup(void* ip)
 {
-    jl_print_native_codeloc((uintptr_t)ip);
+    char pre_str[64];
+    snprintf(pre_str, 64, "thread (%d) ", jl_threadid() + 1);
+    jl_print_native_codeloc(pre_str, (uintptr_t)ip);
 }
 
 // Print backtrace for current exception in catch block
@@ -1372,7 +1385,7 @@ JL_DLLEXPORT void jlbacktrace(void) JL_NOTSAFEPOINT
     size_t i, bt_size = jl_excstack_bt_size(s, s->top);
     jl_bt_element_t *bt_data = jl_excstack_bt_data(s, s->top);
     for (i = 0; i < bt_size; i += jl_bt_entry_size(bt_data + i)) {
-        jl_print_bt_entry_codeloc(bt_data + i);
+        jl_print_bt_entry_codeloc(-1, bt_data + i);
     }
 }
 
@@ -1387,7 +1400,7 @@ JL_DLLEXPORT void jlbacktracet(jl_task_t *t) JL_NOTSAFEPOINT
     size_t bt_size = r.bt_size;
     size_t i;
     for (i = 0; i < bt_size; i += jl_bt_entry_size(bt_data + i)) {
-        jl_print_bt_entry_codeloc(bt_data + i);
+        jl_print_bt_entry_codeloc(-1, bt_data + i);
     }
     if (bt_size == 0)
         jl_safe_printf("      no backtrace recorded\n");