wrote verbose_abort in assembly to avoid call to vsprintf

Author: ZERICO2005

src/libcxx/abort_message.cpp

@@ -20,13 +20,16 @@ void __abort_message(const char *message) {
     abort();
 }
 
-void __libcpp_verbose_abort(char const* format, ...) {
+#if 0
+// Assembly version is used instead so we can avoid calling vsprintf
+void __libcpp_verbose_abort(const char *format, ...) {
     va_list list;
     va_start(list, format);
     std::vsprintf(dbgerr, format, list);
     va_end(list);
 
     abort();
 }
+#endif
 
 _LIBCPP_END_NAMESPACE_STD

src/libcxx/verbose_abort.src

@@ -0,0 +1,26 @@
+	.assume	adl=1
+
+	.section	.text
+
+	.global	__ZNSt3__122__libcpp_verbose_abortEPKcz
+	.type	__ZNSt3__122__libcpp_verbose_abortEPKcz,@function
+
+; void __libcpp_verbose_abort(const char *format, ...)
+__ZNSt3__122__libcpp_verbose_abortEPKcz:
+	; sp + 6 : args...
+	; sp + 3 : format
+	; sp + 0 : ret
+	ld	hl, $FC0000	; dbgerr
+	ex	(sp), hl	; destroys previous return address
+
+	; _boot_sprintf will return to _abort
+	ld	hl, _abort
+	push	hl
+	; sp + 9 : args...
+	; sp + 6 : format
+	; sp + 3 : dbgerr
+	; sp + 0 : _abort
+	jp	_boot_sprintf
+
+	.extern	_abort
+	.extern	_boot_sprintf