From: Patrick Palka <ppalka@redhat.com>
Date: Mon, 15 May 2023 16:01:07 +0000 (-0400)
Subject: c++: add feature-test macro for auto(x)
X-Git-Tag: vendors/ARM/release-12.3.rel1~105
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=a4d13e54822dddda4a53137c9f5e23770a798a0b;p=thirdparty%2Fgcc.git

c++: add feature-test macro for auto(x)

This adds the feature-test macro for PR0849R8, as per
https://github.com/cplusplus/CWG/issues/281.

gcc/c-family/ChangeLog:

	* c-cppbuiltin.cc (c_cpp_builtins): Predefine __cpp_auto_cast
	for C++23.

gcc/testsuite/ChangeLog:

	* g++.dg/cpp23/feat-cxx2b.C: Test __cpp_auto_cast.

(cherry picked from commit 32b81d897629b6c3bd9e2780831a1c45b38b5ac3)
---

diff --git a/gcc/c-family/c-cppbuiltin.cc b/gcc/c-family/c-cppbuiltin.cc
index 4672ae8486a7..c1b86c1fac09 100644
--- a/gcc/c-family/c-cppbuiltin.cc
+++ b/gcc/c-family/c-cppbuiltin.cc
@@ -1080,6 +1080,7 @@ c_cpp_builtins (cpp_reader *pfile)
 	  cpp_define (pfile, "__cpp_if_consteval=202106L");
 	  cpp_define (pfile, "__cpp_constexpr=202110L");
 	  cpp_define (pfile, "__cpp_multidimensional_subscript=202110L");
+	  cpp_define (pfile, "__cpp_auto_cast=202110L");
 	}
       if (flag_concepts)
         {
diff --git a/gcc/testsuite/g++.dg/cpp23/feat-cxx2b.C b/gcc/testsuite/g++.dg/cpp23/feat-cxx2b.C
index c1f91e78e66c..d8a1acd17df4 100644
--- a/gcc/testsuite/g++.dg/cpp23/feat-cxx2b.C
+++ b/gcc/testsuite/g++.dg/cpp23/feat-cxx2b.C
@@ -557,3 +557,9 @@
 #elif __cpp_multidimensional_subscript != 202110
 #  error "__cpp_multidimensional_subscript != 202110"
 #endif
+
+#ifndef __cpp_auto_cast
+#  error "__cpp_auto_cast"
+#elif __cpp_auto_cast != 202110
+#  error "__cpp_auto_cast != 202110"
+#endif