From 61b60273ea15de9bdb29847ea03581d55dabc327 Mon Sep 17 00:00:00 2001
From: dearblue <dearblue@users.osdn.me>
Date: Sun, 20 Nov 2022 20:58:03 +0900
Subject: [PATCH] Print errors by calling `mrb_print_backtrace()` without
 backtrace

- In case of `NoMemoryError` exceptions, the error message is now printed directly.
- Replaced `mrb_p()` used by #4250 with `mrb_print_error()`.

  ref. squashed commit f1523d24042ca3416dc5b9be7b3fc220ddaed896
  ref. subcommit da7d7f881bbbad9988a3a2b7bad8f2b72ff06bc6
  ref. subcommit d9c7b6be6eb54630b64eea5c35be241e551676e5
---
 src/backtrace.c | 23 ++++++++++++++++-------
 src/error.c     |  4 ++--
 2 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/src/backtrace.c b/src/backtrace.c
index 30b496927..12f835660 100644
--- a/src/backtrace.c
+++ b/src/backtrace.c
@@ -100,7 +100,7 @@ static void
 print_backtrace(mrb_state *mrb, struct RObject *exc, struct RArray *backtrace)
 {
   mrb_int i;
-  mrb_int n = ARY_LEN(backtrace);
+  mrb_int n = (backtrace ? ARY_LEN(backtrace) : 0);
   mrb_value *loc, mesg;
 
   if (n != 0) {
@@ -117,9 +117,19 @@ print_backtrace(mrb_state *mrb, struct RObject *exc, struct RArray *backtrace)
       fprintf(stderr, "%.*s: ", (int)RSTRING_LEN(*loc), RSTRING_PTR(*loc));
     }
   }
-  mesg = mrb_exc_inspect(mrb, mrb_obj_value(exc));
-  fwrite(RSTRING_PTR(mesg), RSTRING_LEN(mesg), 1, stderr);
-  fputc('\n', stderr);
+  else {
+    fprintf(stderr, "%s:0: ", "(unknown)");
+  }
+
+  if (exc == mrb->nomem_err) {
+    static const char nomem[] = "Out of memory (NoMemoryError)\n";
+    fwrite(nomem, sizeof(nomem) - 1, 1, stderr);
+  }
+  else {
+    mesg = mrb_exc_inspect(mrb, mrb_obj_value(exc));
+    fwrite(RSTRING_PTR(mesg), RSTRING_LEN(mesg), 1, stderr);
+    fputc('\n', stderr);
+  }
 }
 
 /* mrb_print_backtrace
@@ -130,13 +140,12 @@ print_backtrace(mrb_state *mrb, struct RObject *exc, struct RArray *backtrace)
 MRB_API void
 mrb_print_backtrace(mrb_state *mrb)
 {
-  if (!mrb->exc) {
+  if (!mrb->exc || mrb->exc->tt != MRB_TT_EXCEPTION) {
     return;
   }
 
   struct RObject *backtrace = ((struct RException*)mrb->exc)->backtrace;
-  if (!backtrace) return;
-  if (backtrace->tt != MRB_TT_ARRAY) backtrace = mrb_unpack_backtrace(mrb, backtrace);
+  if (backtrace && backtrace->tt != MRB_TT_ARRAY) backtrace = mrb_unpack_backtrace(mrb, backtrace);
   print_backtrace(mrb, mrb->exc, (struct RArray*)backtrace);
 }
 #else
diff --git a/src/error.c b/src/error.c
index 1f2788729..a0e23fad4 100644
--- a/src/error.c
+++ b/src/error.c
@@ -195,7 +195,7 @@ static mrb_noreturn void
 exc_throw(mrb_state *mrb, mrb_value exc)
 {
   if (!mrb->jmp) {
-    mrb_p(mrb, exc);
+    mrb_print_error(mrb);
     abort();
   }
   MRB_THROW(mrb->jmp);
@@ -576,7 +576,7 @@ mrb_core_init_protect(mrb_state *mrb, void (*body)(mrb_state *, void *), void *o
     err = 0;
   } MRB_CATCH(&c_jmp) {
     if (mrb->exc) {
-      mrb_p(mrb, mrb_obj_value(mrb->exc));
+      mrb_print_error(mrb);
       mrb->exc = NULL;
     }
     else {