gcc/libstdc++-v3
Jonathan Wakely 6b42b5a8a2 libstdc++: Use __builtin_unreachable for constexpr assertions [PR 100676]
The current implementation of compile-time precondition checks causes
compilation to fail by calling a non-constexpr function declared at
block scope. This breaks the CUDA compiler, which wraps some libstdc++
headers in a pragma that declares everything as a __host__ __device__
function, but others are not wrapped and so everything is a __host__
function. The local declaration thus gets redeclared as two different
types of function, which doesn't work.

Just use __builtin_unreachable to make constant evaluation fail, instead
of the local function declaration. Also simplify the assertion macros,
which has the side effect of giving simpler compilation errors when
using Clang.

libstdc++-v3/ChangeLog:

	PR libstdc++/100676
	* include/bits/c++config (__glibcxx_assert_1): Rename to ...
	(__glibcxx_constexpr_assert): ... this.
	(__glibcxx_assert_impl): Use __glibcxx_constexpr_assert.
	(__glibcxx_assert): Define as either __glibcxx_constexpr_assert
	or __glibcxx_assert_impl.
	(__glibcxx_assert_2): Remove
	* include/debug/macros.h (_GLIBCXX_DEBUG_VERIFY_AT_F): Use
	__glibcxx_constexpr_assert instead of __glibcxx_assert_1.
	* testsuite/21_strings/basic_string_view/element_access/char/back_constexpr_neg.cc:
	Adjust expected error.
	* testsuite/21_strings/basic_string_view/element_access/char/constexpr_neg.cc:
	Likewise.
	* testsuite/21_strings/basic_string_view/element_access/char/front_constexpr_neg.cc:
	Likewise.
	Likewise.
	* testsuite/21_strings/basic_string_view/element_access/wchar_t/back_constexpr_neg.cc:
	Likewise.
	* testsuite/21_strings/basic_string_view/element_access/wchar_t/constexpr_neg.cc:
	Likewise.
	* testsuite/21_strings/basic_string_view/element_access/wchar_t/front_constexpr_neg.cc:
	Likewise.
	* testsuite/23_containers/span/back_neg.cc: Likewise.
	* testsuite/23_containers/span/front_neg.cc: Likewise.
	* testsuite/23_containers/span/index_op_neg.cc: Likewise.
2021-05-20 20:49:57 +01:00
..
config ctype support for libstdc++ on VxWorks 2021-05-04 21:49:43 -03:00
doc libstdc++: Allow lualatex to be used for Doxygen PDF 2021-05-17 12:13:41 +01:00
include libstdc++: Use __builtin_unreachable for constexpr assertions [PR 100676] 2021-05-20 20:49:57 +01:00
libsupc++ libstdc++: Move atomic functions to libsupc++ [PR 96657] 2021-04-15 16:56:44 +01:00
po Update copyright years. 2021-01-04 10:26:59 +01:00
python libstdc++: Install libstdc++*-gdb.py more robustly [PR 99453] 2021-04-21 16:55:15 +01:00
scripts libstdc++: Allow lualatex to be used for Doxygen PDF 2021-05-17 12:13:41 +01:00
src libstdc++: Disable floating_to_chars.cc on 16 bit targets 2021-05-20 13:21:41 +01:00
testsuite libstdc++: Use __builtin_unreachable for constexpr assertions [PR 100676] 2021-05-20 20:49:57 +01:00
acinclude.m4 ctype support for libstdc++ on VxWorks 2021-05-04 21:49:43 -03:00
aclocal.m4 Add `--with-toolexeclibdir=' configuration option 2020-01-24 11:24:25 +00:00
ChangeLog Daily bump. 2021-05-19 00:16:45 +00:00
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ChangeLog-2019 libstdc++: Fix whitespace in ChangeLog-2019 2020-01-09 21:31:35 +00:00
ChangeLog-2020 libstdc++: Fix typo in ChangeLog-2020 2021-01-13 11:02:13 +00:00
config.h.in libstdc++: Remove _GLIBCXX_USE_INT128 autoconf macro 2021-05-04 12:07:09 +01:00
configure ctype support for libstdc++ on VxWorks 2021-05-04 21:49:43 -03:00
configure.ac libstdc++: Remove _GLIBCXX_USE_INT128 autoconf macro 2021-05-04 12:07:09 +01:00
configure.host Scope libstdc++ configuration for vxworks to all versions 2020-10-22 16:40:57 +00:00
crossconfig.m4 Scope libstdc++ configuration for vxworks to all versions 2020-10-22 16:40:57 +00:00
fragment.am libstdc++: Add C++ runtime support for new 128-bit long double format 2020-12-16 23:25:01 +00:00
linkage.m4
Makefile.am Update copyright years. 2021-01-04 10:26:59 +01:00
Makefile.in libstdc++: Add C++ runtime support for new 128-bit long double format 2020-12-16 23:25:01 +00:00
README

file: libstdc++-v3/README

New users may wish to point their web browsers to the file
index.html in the 'doc/html' subdirectory.  It contains brief
building instructions and notes on how to configure the library in
interesting ways.