Document ASAN_OPTIONS="halt_on_error" env variable.

	* doc/invoke.texi: Explain connection between -fsanitize-recover=address
	and ASAN_OPTIONS="halt_on_error=1".

From-SVN: r236172

gcc/ChangeLog

+2016-05-12  Martin Liska  <mliska@suse.cz>
+
+	* doc/invoke.texi: Explain connection between -fsanitize-recover=address
+	and ASAN_OPTIONS="halt_on_error=1".
+
 2016-05-12  Ilya Enkovich  <ilya.enkovich@intel.com>
 
 	PR tree-optimization/71006

gcc/doc/invoke.texi

@@ -10007,6 +10007,14 @@ for which this feature is experimental.
 accepted, the former enables recovery for all sanitizers that support it,
 the latter disables recovery for all sanitizers that support it.
 
+Even if a recovery mode is turned on the compiler side, it needs to be also
+enabled on the runtime library side, otherwise the failures are still fatal.
+The runtime library defaults to @code{halt_on_error=0} for
+ThreadSanitizer and UndefinedBehaviorSanitizer, while default value for
+AddressSanitizer is @code{halt_on_error=1}. This can overridden through
+the following environment variables: @env{ASAN_OPTIONS}, @env{TSAN_OPTIONS},
+@env{UBSAN_OPTIONS}.
+
 Syntax without explicit @var{opts} parameter is deprecated.  It is equivalent to
 @smallexample
 -fsanitize-recover=undefined,float-cast-overflow,float-divide-by-zero