2018-09-21 Florian Weimer <fwei...@redhat.com>
PR middle-end/81035
* doc/extend.texi (Common Function Attributes): Mention that
noreturn suppresses tail call optimization.
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index e3312aa8b42..909e7a17357 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -3157,6 +3157,9 @@ The @code{noreturn} keyword does not affect the
exceptional path when that
applies: a @code{noreturn}-marked function may still return to the caller
by throwing an exception or calling @code{longjmp}.
+In order to preserve backtraces, GCC will never turn calls to
+@code{noreturn} functions into tail calls.
+
Do not assume that registers saved by the calling function are
restored before calling the @code{noreturn} function.
