typedef rb_jmpbuf_t to void *[5] if __builtin_setjmp is used

The built-in version operates on a buffer of 5 words, much smaller than
the size of jmp_buf defined in libc.
Note, powerpc requires 5 words, while arm and x86_64 just require 3.

1 files changed, 4 insertions, 0 deletions

diff --git a/vm_core.h b/vm_core.h
index 99c4d13f66..bc7e6bec55 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -775,7 +775,11 @@ enum rb_thread_status {
     THREAD_KILLED
 };
 
+#ifdef RUBY_JMP_BUF
 typedef RUBY_JMP_BUF rb_jmpbuf_t;
+#else
+typedef void *rb_jmpbuf_t[5];
+#endif
 
 /*
   the members which are written in EC_PUSH_TAG() should be placed at