From: Tomasz Kamiński <tkaminsk@redhat.com>
Date: Wed, 16 Jul 2025 08:49:48 +0000 (+0200)
Subject: libstdc++: Do not define __cpp_lib_constexpr_exceptions [PR121114]
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=c163bbd75b600cc6d1ec752425ee895ef5b9b37d;p=thirdparty%2Fgcc.git

libstdc++: Do not define __cpp_lib_constexpr_exceptions [PR121114]

Do not advertise library support for constexpr exceptions, as our
solution to throwing by __throw_* functions from <bits/functexcept.h>,
caues constant evaluation to fail, as these functions are not constexpr.

	PR libstdc++/121114

libstdc++-v3/ChangeLog:

	* include/bits/version.def (constexpr_exceptions): Add no_stdname
	and changed value.
	* include/bits/version.h: Regenerated.
	* testsuite/18_support/exception/version.cc: Test that macro is
	not exported.

Reviewed-by: Jonathan Wakely <jwakely@redhat.com>
Signed-off-by: Tomasz Kaminski <tkaminsk@redhat.com>
---

diff --git a/libstdc++-v3/include/bits/version.def b/libstdc++-v3/include/bits/version.def
index cf0672b4822..2f70a529927 100644
--- a/libstdc++-v3/include/bits/version.def
+++ b/libstdc++-v3/include/bits/version.def
@@ -2052,8 +2052,10 @@ ftms = {
 
 ftms = {
   name = constexpr_exceptions;
+  // TODO Remove when PR121114 is resolved
+  no_stdname = true;
   values = {
-    v = 202411;
+    v = 1; // TODO 202411;
     cxxmin = 26;
     extra_cond = "__cpp_constexpr_exceptions >= 202411L";
   };
diff --git a/libstdc++-v3/include/bits/version.h b/libstdc++-v3/include/bits/version.h
index c01ddf14dd5..8e0ae682251 100644
--- a/libstdc++-v3/include/bits/version.h
+++ b/libstdc++-v3/include/bits/version.h
@@ -2301,9 +2301,8 @@
 
 #if !defined(__cpp_lib_constexpr_exceptions)
 # if (__cplusplus >  202302L) && (__cpp_constexpr_exceptions >= 202411L)
-#  define __glibcxx_constexpr_exceptions 202411L
+#  define __glibcxx_constexpr_exceptions 1L
 #  if defined(__glibcxx_want_all) || defined(__glibcxx_want_constexpr_exceptions)
-#   define __cpp_lib_constexpr_exceptions 202411L
 #  endif
 # endif
 #endif /* !defined(__cpp_lib_constexpr_exceptions) && defined(__glibcxx_want_constexpr_exceptions) */
diff --git a/libstdc++-v3/testsuite/18_support/exception/version.cc b/libstdc++-v3/testsuite/18_support/exception/version.cc
index 09a2d102b72..5707abd732f 100644
--- a/libstdc++-v3/testsuite/18_support/exception/version.cc
+++ b/libstdc++-v3/testsuite/18_support/exception/version.cc
@@ -3,8 +3,7 @@
 
 #include <exception>
 
-#ifndef __cpp_lib_constexpr_exceptions
-# error "Feature test macro for constexpr_exceptions is missing in <exception>"
-#elif __cpp_lib_constexpr_exceptions < 202411L
-# error "Feature test macro for constexpr_exceptions has wrong value in <exception>"
+#ifdef __cpp_lib_constexpr_exceptions
+# error "Feature test macro for constexpr_exceptions should not be provided by <exception>"
 #endif
+