doc: install: document UBSAN_OPTIONS

Explain that 'bootstrap-ubsan' won't abort on errors by default and how
to override that by setting UBSAN_OPTIONS.

gcc/ChangeLog:
	PR other/116948

	* doc/install.texi (Building a native compiler): Document UBSAN_OPTIONS.

diff --git a/gcc/doc/install.texi b/gcc/doc/install.texi
index d1fc7220db9dc5eacba083af71b1823505ca1aff..705440ffd330d117fe4b1d9da55fa776a9609274 100644 (file)
--- a/gcc/doc/install.texi
+++ b/gcc/doc/install.texi
@@ -3149,7 +3149,9 @@ systems that are running Linux kernel version 5.4 or later.
 
 @item @samp{bootstrap-ubsan}
 Compiles GCC itself using Undefined Behavior Sanitization in order to catch
-undefined behavior within the GCC code.
+undefined behavior within the GCC code.  Note that it does not abort on errors
+by default.  @code{UBSAN_OPTIONS} can be set to change this, like
+@samp{UBSAN_OPTIONS='abort_on_error=1:halt_on_error=1:print_summary=1:print_stacktrace=1'}.
 
 @end table