Merge pull request #13344 from stedolan/better-failed-assert

Make caml_failed_assert friendlier to debuggers

runtime/caml/misc.h

@@ -274,9 +274,20 @@ typedef char char_os;
 #define __OSFILE__ __FILE__
 #endif
 
+/* Although caml_failed_assert never returns, it is not marked as such.
+   This prevents the C compiler optimising away all of the useful context
+   from the callsite, making debuggers able to see it. */
 #define CAMLassert(x) \
   (CAMLlikely(x) ? (void) 0 : caml_failed_assert ( #x , __OSFILE__, __LINE__))
-CAMLnoret CAMLextern void caml_failed_assert (char *, char_os *, int);
+CAMLextern void caml_failed_assert (char *, char_os *, int)
+#if defined(__has_feature)
+  /* However, we do inform clang-analyzer that this function never returns,
+     since that improves analysis without breaking debugging */
+  #if __has_feature(attribute_analyzer_noreturn)
+    __attribute__((analyzer_noreturn))
+  #endif
+#endif
+;
 #else
 #define CAMLassert(x) ((void) 0)
 #endif

runtime/misc.c

@@ -44,6 +44,9 @@ void caml_failed_assert (char * expr, char_os * file_os, int line)
           (Caml_state_opt != NULL) ? Caml_state_opt->id : -1, file, line, expr);
   fflush(stderr);
   caml_stat_free(file);
+#if __has_builtin(__builtin_trap) || defined(__GNUC__)
+  __builtin_trap();
+#endif
   abort();
 }
 #endif