On 2/3/26 12:16 AM, Patrick Palka wrote:
On Mon, 2 Feb 2026, Jakub Jelinek wrote:
On Mon, Feb 02, 2026 at 10:46:28AM -0500, Patrick Palka wrote:
Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look
OK for trunk and perhaps 14/15?
-- >8 --
As per https://github.com/cplusplus/draft/pull/8450
gcc/c-family/ChangeLog:
* c-cppbuiltin.cc (c_cpp_builtins): Bump __cpp_deduction_guides to
202207L for C++23.
gcc/testsuite/ChangeLog:
* g++.dg/cpp23/feat-cxx2b.C: Adjust expected __cpp_deduction_guides
value.
No changes to gcc/testsuite/g++.dg/cpp26/feat-cxx26.C ?
D'oh, I conflated the two test failures.. Here's an update patch that
I'm retesting:
OK. Backporting seems fine to releases that do in fact implement the
feature.
-- >8 --
Subject: [PATCH] c++: update FTM for C++23 inherited CTAD
As per https://github.com/cplusplus/draft/pull/8450
gcc/c-family/ChangeLog:
* c-cppbuiltin.cc (c_cpp_builtins): Bump __cpp_deduction_guides to
202207L for C++23.
gcc/testsuite/ChangeLog:
* g++.dg/cpp23/feat-cxx2b.C: Adjust expected __cpp_deduction_guides
value.
* g++.dg/cpp26/feat-cxx26.C: Likewise.
---
gcc/c-family/c-cppbuiltin.cc | 4 +++-
gcc/testsuite/g++.dg/cpp23/feat-cxx2b.C | 4 ++--
gcc/testsuite/g++.dg/cpp26/feat-cxx26.C | 4 ++--
3 files changed, 7 insertions(+), 5 deletions(-)
diff --git a/gcc/c-family/c-cppbuiltin.cc b/gcc/c-family/c-cppbuiltin.cc
index 12ddfa22074c..48095988da56 100644
--- a/gcc/c-family/c-cppbuiltin.cc
+++ b/gcc/c-family/c-cppbuiltin.cc
@@ -1079,7 +1079,8 @@ c_cpp_builtins (cpp_reader *pfile)
cpp_define (pfile, "__cpp_conditional_explicit=201806L");
cpp_define (pfile, "__cpp_consteval=202211L");
cpp_define (pfile, "__cpp_constinit=201907L");
- cpp_define (pfile, "__cpp_deduction_guides=201907L");
+ if (cxx_dialect <= cxx20)
+ cpp_define (pfile, "__cpp_deduction_guides=201907L");
cpp_define (pfile, "__cpp_nontype_template_args=201911L");
cpp_define (pfile, "__cpp_nontype_template_parameter_class=201806L");
cpp_define (pfile, "__cpp_impl_destroying_delete=201806L");
@@ -1096,6 +1097,7 @@ c_cpp_builtins (cpp_reader *pfile)
cpp_define (pfile, "__cpp_auto_cast=202110L");
if (cxx_dialect <= cxx23)
cpp_define (pfile, "__cpp_constexpr=202211L");
+ cpp_define (pfile, "__cpp_deduction_guides=202207L");
cpp_define (pfile, "__cpp_multidimensional_subscript=202211L");
cpp_define (pfile, "__cpp_named_character_escapes=202207L");
cpp_define (pfile, "__cpp_static_call_operator=202207L");
diff --git a/gcc/testsuite/g++.dg/cpp23/feat-cxx2b.C
b/gcc/testsuite/g++.dg/cpp23/feat-cxx2b.C
index 4033552b2ebc..06901afadb62 100644
--- a/gcc/testsuite/g++.dg/cpp23/feat-cxx2b.C
+++ b/gcc/testsuite/g++.dg/cpp23/feat-cxx2b.C
@@ -353,8 +353,8 @@
#ifndef __cpp_deduction_guides
# error "__cpp_deduction_guides"
-#elif __cpp_deduction_guides != 201907
-# error "__cpp_deduction_guides != 201907"
+#elif __cpp_deduction_guides != 202207
+# error "__cpp_deduction_guides != 202207"
#endif
#ifndef __cpp_if_constexpr
diff --git a/gcc/testsuite/g++.dg/cpp26/feat-cxx26.C
b/gcc/testsuite/g++.dg/cpp26/feat-cxx26.C
index 08c0ed457af3..248116699617 100644
--- a/gcc/testsuite/g++.dg/cpp26/feat-cxx26.C
+++ b/gcc/testsuite/g++.dg/cpp26/feat-cxx26.C
@@ -353,8 +353,8 @@
#ifndef __cpp_deduction_guides
# error "__cpp_deduction_guides"
-#elif __cpp_deduction_guides != 201907
-# error "__cpp_deduction_guides != 201907"
+#elif __cpp_deduction_guides != 202207
+# error "__cpp_deduction_guides != 202207"
#endif
#ifndef __cpp_if_constexpr
