re PR c++/43105 (Document restrictions on mixing -fno-rtti and -frtti)

2018-11-11  Sandra Loosemore  <sandra@codesourcery.com>

	PR c++/43105

	gcc/
	* doc/invoke.texi (C++ Dialect Options): Add warning about mixing
	-frtti and -fno-rtti code.

From-SVN: r266020

gcc/ChangeLog

 2018-11-11  Sandra Loosemore  <sandra@codesourcery.com>
 
+	PR c++/43105
+	* doc/invoke.texi (C++ Dialect Options): Add warning about mixing
+	-frtti and -fno-rtti code.
+
+2018-11-11  Sandra Loosemore  <sandra@codesourcery.com>
+
 	PR c/26366
 	* doc/extend.texi (Other Builtins): Document probability associated
 	with __builtin_expect.

gcc/doc/invoke.texi

@@ -2679,6 +2679,11 @@ needed. The @code{dynamic_cast} operator can still be used for casts that
 do not require run-time type information, i.e.@: casts to @code{void *} or to
 unambiguous base classes.
 
+Mixing code compiled with @option{-frtti} with that compiled with
+@option{-fno-rtti} may not work.  For example, programs may
+fail to link if a class compiled with @option{-fno-rtti} is used as a base 
+for a class compiled with @option{-frtti}.  
+
 @item -fsized-deallocation
 @opindex fsized-deallocation
 Enable the built-in global declarations