From 0be3dff1aadcc3e879f3d1ffd45d842ab0e0c0bf Mon Sep 17 00:00:00 2001 From: Jonathan Wakely Date: Wed, 16 Apr 2025 11:44:46 +0100 Subject: libstdc++: Do not use 'not' alternative token in This fixes: FAIL: 17_intro/headers/c++1998/operator_names.cc -std=gnu++23 (test for excess errors) FAIL: 17_intro/headers/c++1998/operator_names.cc -std=gnu++26 (test for excess errors) The purpose of 'not defined>' is to be ill-formed (as required by [format.range.fmtkind]) and to give an error that includes the string "not defined>". That was intended to tell you that format_kind is not defined, just like it says! But user code can use -fno-operator-names so we can't use 'not' here, and "! defined" in the diagnostic doesn't seem as user-friendly. It also raises questions about whether it was intended to be the preprocessor token 'defined' (it's not) or where 'defined' is defined (it's not). Replace it with __primary_template_not_defined> and a comment, which seems to give a fairly clear diagnostic with both GCC and Clang. The diagnostic now looks like: .../include/c++/15.0.1/format:5165:7: error: use of 'std::format_kind' before deduction of 'auto' 5165 | format_kind<_Rg> // you can specialize this for non-const input ranges | ^~~~~~~~~~~~~~~~ .../include/c++/15.0.1/format:5164:35: error: '__primary_template_not_defined' was not declared in this scope 5164 | __primary_template_not_defined( | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^ 5165 | format_kind<_Rg> // you can specialize this for non-const input ranges | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 5166 | ); | ~ libstdc++-v3/ChangeLog: * include/std/format (format_kind): Do not use 'not' alternative token to make the primary template ill-formed. Use the undeclared identifier __primary_template_not_defined and a comment that will appear in diagnostics. * testsuite/std/format/ranges/format_kind_neg.cc: New test. --- libstdc++-v3/testsuite/std/format/ranges/format_kind_neg.cc | 13 +++++++++++++ 1 file changed, 13 insertions(+) create mode 100644 libstdc++-v3/testsuite/std/format/ranges/format_kind_neg.cc (limited to 'libstdc++-v3/testsuite/std') diff --git a/libstdc++-v3/testsuite/std/format/ranges/format_kind_neg.cc b/libstdc++-v3/testsuite/std/format/ranges/format_kind_neg.cc new file mode 100644 index 0000000..bf8619d --- /dev/null +++ b/libstdc++-v3/testsuite/std/format/ranges/format_kind_neg.cc @@ -0,0 +1,13 @@ +// { dg-do compile { target c++23 } } + +// C++23 22.14.7.1 [format.range.fmtkind] p1: A program that instantiates +// the primary template of format_kind is ill-formed. + +#include + +template struct Tester { }; + +Tester> t; // { dg-error "here" } + +// { dg-error "use of 'std::format_kind" "" { target *-*-* } 0 } +// { dg-error "primary_template_not_defined" "" { target *-*-* } 0 } -- cgit v1.1