My previous fix for PR 94749 did fix the reported case, so that the next
character is not discarded if it happens to equal the delimiter when __n
characters have already been read. But it introduced a new bug, which is
that the delimiter character would *not* be discarded if the number of
characters discarded is numeric_limits<streamsize>::max() or more before
reaching the delimiter.
The new bug happens because I changed the code to check _M_gcount < __n.
But when __n == numeric_limits<streamsize>::max() that is false, and so
we don't discard the delimiter. It's not sufficient to check for the
delimiter when the __large_ignore condition is true, because there's an
edge case where the delimiter is reached when _M_gcount == __n and so
we break out of the loop without setting __large_ignore.
PR 96161 is a similar bug to the original PR 94749 report, where eofbit
is set after discarding __n characters if there happen to be no more
characters in the stream.
This patch fixes both cases (and the regression) by checking different
conditions for the __n == max case and the __n < max case. For the
former case, we know that we must have either reached the delimiter or
EOF, and the value of _M_gcount doesn't matter (except to avoid integer
overflow). For the latter case we need to check _M_gcount first and only
set eofbit or discard the delimiter if it didn't reach __n. For the
latter case overflow can't happen because _M_gcount <= __n < max.
libstdc++-v3/ChangeLog:
PR libstdc++/94749
PR libstdc++/96161
* include/bits/istream.tcc (basic_istream::ignore(streamsize))
[n == max]: Check overflow conditions on _M_gcount. Rely on
the fact that either EOF or the delimiter was reached.
[n < max]: Check _M_gcount < n before checking for EOF or
delimiter.
(basic_istream::ignore(streamsize, char_type): Likewise.
* src/c++98/compatibility.cc (istream::ignore(streamsize))
(wistream::ignore(streamsize)): Likewise.
* src/c++98/istream.cc (istream::ignore(streamsize, char_type))
(wistream::ignore(streamsize, char_type)): Likewise.
* testsuite/27_io/basic_istream/ignore/char/94749.cc: Check that
delimiter is discarded if the number of characters ignored
doesn't fit in streamsize.
* testsuite/27_io/basic_istream/ignore/wchar_t/94749.cc:
Likewise.
* testsuite/27_io/basic_istream/ignore/char/96161.cc: New test.
* testsuite/27_io/basic_istream/ignore/wchar_t/96161.cc: New test.
I recently added std::__detail::__int_limits as a lightweight
alternative to std::numeric_limits, forgetting that the values it
provides (digits, min and max) are already provided by
__gnu_cxx::__numeric_traits.
This change adds __int_traits as an alias for __numeric_traits_integer.
This avoids instantiating __numeric_traits to decide whether to use
__numeric_traits_integer or __numeric_traits_floating. Then all uses of
__int_limits can be replaced with __int_traits, and __int_limits can be
removed.
libstdc++-v3/ChangeLog:
* include/Makefile.am: Remove bits/int_limits.h.
* include/Makefile.in: Regenerate.
* include/bits/int_limits.h: Removed.
* include/bits/parse_numbers.h (_Select_int_base): Replace
__int_limits with __int_traits.
* include/bits/range_access.h (_SSize::operator()): Likewise.
* include/ext/numeric_traits.h (__numeric_traits_integer): Add
static assertion.
(__int_traits): New alias template.
* include/std/bit (__rotl, __rotr, __countl_zero, __countl_one)
(__countr_zero, __countr_one, __popcount, __bit_ceil)
(__bit_floor, __bit_width) Replace __int_limits with
__int_traits.
* include/std/charconv (__to_chars_8, __from_chars_binary)
(__from_chars_alpha_to_num, from_chars): Likewise.
* include/std/memory_resource (polymorphic_allocator::allocate)
(polymorphic_allocator::allocate_object): Likewise.
* include/std/string_view (basic_string_view::_S_compare):
Likewise.
* include/std/utility (cmp_equal, cmp_less, in_range): Likewise.
This makes the formatting in <optional> consistent and also removes
redundant && tokens from template arguments for traits like
is_constructible and is_convertible.
libstdc++-v3/ChangeLog:
* include/std/optional (_Optional_payload_base, _Optional_base)
(optional, __optional_hash_call_base): Adjust whitespace and
other formatting. Remove redundant && tokens on template
arguments to type traits.
The standard rquires that std::make_optional is constrained similarly to
the std::optional constructors, which our implementation fails to do.
As a conforming extension this also adds a noexcept-specifier to each
std::make_optional overload.
libstdc++-v3/ChangeLog:
* include/std/optional (make_optional): Add enable_if
constraints and noexcept-specifier to each overload.
* testsuite/20_util/optional/make_optional-2.cc: New test.
libstdc++-v3/ChangeLog:
PR libstdc++/96036
* include/std/optional (optional): Add noexcept-specifier to
every constructor, assignment operator, emplace function and
dereference operator.
* testsuite/20_util/optional/assignment/noexcept.cc: New test.
* testsuite/20_util/optional/cons/noexcept.cc: New test.
This test checks a conversion which only exists in C++98 and won't
compile since C++11. It uses { dg-options "-std=gnu++98" } so that it is
explicitly run in C++98 mode. This change also adds a target selector so
that the test will be skipped if the dg-options directive is filtered
out or overridden.
libstdc++-v3/ChangeLog:
* testsuite/27_io/basic_ios/conv/voidptr.cc: Add c++98_only
target selector.
These tests verify that including C++11 headers fails to compile in
C++98 mode. They use { dg-options "-std=gnu++98" } so that they are
explicitly run in C++98 mode. This change also adds a target selector so
that the tests will be skipped even if the dg-options directive is
filtered out or overridden. This is in preparation for a desired future
change where tests do not use -std options, so that they can be tested
with e.g. --target_board=unix\"{-std=gnu++17,-std=gnu++20}\"
In some cases the dg-options and dg-do directives need to be reordered,
so that the -std=gnu++98 option is already added to the options before
the target selector is checked.
libstdc++-v3/ChangeLog:
* testsuite/18_support/headers/cstdalign/std_c++0x_neg.cc: Add
c++98_only target selector.
* testsuite/18_support/headers/cstdbool/std_c++0x_neg.cc:
Likewise.
* testsuite/18_support/headers/cstdint/std_c++0x_neg.cc:
Likewise.
* testsuite/18_support/headers/new/synopsis_cxx98.cc: Likewise.
* testsuite/19_diagnostics/headers/system_error/std_c++0x_neg.cc:
Likewise.
* testsuite/20_util/headers/type_traits/std_c++0x_neg.cc:
Likewise.
* testsuite/23_containers/headers/array/std_c++0x_neg.cc:
Likewise.
* testsuite/23_containers/headers/tuple/std_c++0x_neg.cc:
Likewise.
* testsuite/23_containers/headers/unordered_map/std_c++0x_neg.cc:
Likewise.
* testsuite/23_containers/headers/unordered_set/std_c++0x_neg.cc:
Likewise.
* testsuite/26_numerics/headers/ccomplex/std_c++0x_neg.cc:
Likewise.
* testsuite/26_numerics/headers/cfenv/std_c++0x_neg.cc:
Likewise.
* testsuite/26_numerics/headers/cmath/c99_classification_macros_c++98.cc:
Likewise.
* testsuite/26_numerics/headers/ctgmath/std_c++0x_neg.cc:
Likewise.
* testsuite/26_numerics/headers/random/std_c++0x_neg.cc:
Likewise.
* testsuite/27_io/headers/cinttypes/std_c++0x_neg.cc: Likewise.
* testsuite/28_regex/headers/regex/std_c++0x_neg.cc: Likewise.
* testsuite/29_atomics/headers/atomic/std_c++0x_neg.cc:
Likewise.
* testsuite/30_threads/headers/condition_variable/std_c++0x_neg.cc:
Likewise.
* testsuite/30_threads/headers/future/std_c++0x_neg.cc:
Likewise.
* testsuite/30_threads/headers/mutex/std_c++0x_neg.cc: Likewise.
* testsuite/30_threads/headers/thread/std_c++0x_neg.cc:
Likewise.
PR libstdc++/91807
* include/std/variant
(_Copy_assign_base::operator=(const _Copy_assign_base&):
Do the move-assignment from a temporary so that the temporary
is constructed with an explicit index.
* testsuite/20_util/variant/91807.cc: New.
These tests fail with AIX double double. Use different floating point
values that behave less surprisingly.
libstdc++-v3/ChangeLog:
PR libstdc++/91153
PR target/93224
* testsuite/29_atomics/atomic_float/1.cc: Use different values
for tests.
* testsuite/29_atomics/atomic_ref/float.cc: Likewise.
These functions can't be noexcept because the iterators stored in the
sub_match objects can throw on any operation.
libstdc++-v3/ChangeLog:
PR libstdc++/94627
* include/bits/regex.h (operator==, operator!=): Remove noexcept
equality comparisons for match_results.
* testsuite/28_regex/match_results/94627.cc: New test.
The parser for binary numbers returned an error if the entire string
contains more digits than the result type. Leading zeros should be
ignored.
libstdc++-v3/ChangeLog:
* include/std/charconv (__from_chars_binary): Ignore leading zeros.
* testsuite/20_util/from_chars/1.cc: Check "0x1" for all bases,
not just 10 and 16.
* testsuite/20_util/from_chars/3.cc: New test.
The __detail::__to_chars_2 function assumes it won't be called with zero
values. However, when the output buffer is empty the caller doesn't
handle zero values correctly, and calls __to_chars_2 with a zero value,
resulting in an overflow of the empty buffer.
The __detail::__to_chars_i function should just return immediately for
an empty buffer, and otherwise ensure zero values are handled properly.
libstdc++-v3/ChangeLog:
PR libstdc++/95851
* include/std/charconv (__to_chars_i): Check for zero-sized
buffer unconditionally.
* testsuite/20_util/to_chars/95851.cc: New test.
Also test with an enumeration type. Move the dg-error directives outside
the #if block, because DejaGnu would process them whether or not wchar_t
support is present.
libstdc++-v3/ChangeLog:
* testsuite/20_util/from_chars/1_c++20_neg.cc: Check enumeration
type.
* testsuite/20_util/from_chars/1_neg.cc: Likewise. Move dg-error
directives outside preprocessor condition.
G++ implements P1972R2 since r11-1597-0ca22d027ecc and so we no longer
need the P0608R3 special case to prevent narrowing conversions to bool.
Since non-GNU compilers don't necessarily implment P1972R2 yet, this
may cause a regression for those compilers. There is no feature-test
macro we can use to detect it though, so we'll have to live with it.
libstdc++-v3/ChangeLog:
PR libstdc++/95832
* include/std/variant (__detail::__variant::_Build_FUN): Remove
partial specialization to prevent narrowing conversions to bool.
* testsuite/20_util/variant/compile.cc: Test non-narrowing
conversions to bool.
* testsuite/20_util/variant/run.cc: Likewise.
Automake and GNU Make both use the endif keyword, which conflicts and
elicits an error for matching if/ifdef and endif.
This patch changes the conditional include to use "-include" to prevent
a warning about a possible empty tmake_file.
libgomp/ChangeLog
2020-06-22 David Edelsohn <dje.gcc@gmail.com>
* Makefile.am: Use -include.
* Makefile.in: Regenerate.
libatomic/ChangeLog
2020-06-22 David Edelsohn <dje.gcc@gmail.com>
* Makefile.am: Use -include.
* Makefile.in: Regenerate.
libstdc++-v3/ChangeLog
2020-06-22 David Edelsohn <dje.gcc@gmail.com>
* Makefile.am: Use -include.
* Makefile.in: Regenerate.
libgfortran/ChangeLog
2020-06-22 David Edelsohn <dje.gcc@gmail.com>
* Makefile.am: Use -include.
* Makefile.in: Regenerate.
This patch adds the ability to configure GCC on AIX to build as a
64 bit application and to build target libraries "FAT" libraries in both
32 bit and 64 bit mode.
The patch adds makefile fragment hooks to target libraries that allows
them to include target-specific rules. The target specific rules for
AIX place both 32 bit and 64 bit objects and shared objects
in archives at the top-level, not multilib subdirectories. The
multilibs are built in subdirectories, but must be combined during the
last parts of the target library build process. Because of the way
that GCC bootstrap works, the libraries must be combined during the
multiple stages of GCC bootstrap, not solely when installed in the
final destination, so the libraries are correct at the end of
each target library build stage, not solely an install recipe.
gcc/ChangeLog
2020-06-21 David Edelsohn <dje.gcc@gmail.com>
* config.gcc: Use t-aix64, biarch64 and default64 for cpu_is_64bit.
* config/rs6000/aix72.h (ASM_SPEC): Remove aix64 option.
(ASM_SPEC32): New.
(ASM_SPEC64): New.
(ASM_CPU_SPEC): Remove vsx and altivec options.
(CPP_SPEC_COMMON): Rename from CPP_SPEC.
(CPP_SPEC32): New.
(CPP_SPEC64): New.
(CPLUSPLUS_CPP_SPEC): Rename to CPLUSPLUS_CPP_SPEC_COMMON..
(TARGET_DEFAULT): Only define if not BIARCH.
(LIB_SPEC_COMMON): Rename from LIB_SPEC.
(LIB_SPEC32): New.
(LIB_SPEC64): New.
(LINK_SPEC_COMMON): Rename from LINK_SPEC.
(LINK_SPEC32): New.
(LINK_SPEC64): New.
(STARTFILE_SPEC): Add 64 bit version of crtcxa and crtdbase.
(ASM_SPEC): Define 32 and 64 bit alternatives using DEFAULT_ARCH64_P.
(CPP_SPEC): Same.
(CPLUSPLUS_CPP_SPEC): Same.
(LIB_SPEC): Same.
(LINK_SPEC): Same.
(SUBTARGET_EXTRA_SPECS): Add new 32/64 specs.
* config/rs6000/defaultaix64.h: New file.
* config/rs6000/t-aix64: New file.
libgcc/ChangeLog
2020-06-21 David Edelsohn <dje.gcc@gmail.com>
* config.host (extra_parts): Add crtcxa_64 and crtdbase_64.
* config/rs6000/t-aix-cxa: Explicitly compile 32 bit with -maix32
and 64 bit with -maix64.
* config/rs6000/t-slibgcc-aix: Remove extra @multilib_dir@ level.
Build and install AIX-style FAT libraries.
libgomp/ChangeLog
2020-06-21 David Edelsohn <dje.gcc@gmail.com>
* Makefile.am (tmake_file): Build and install AIX-style FAT libraries.
* Makefile.in: Regenerate
* configure.ac (tmake_file): Substitute.
* configure: Regenerate.
* configure.tgt (powerpc-ibm-aix*): Define tmake_file.
* config/t-aix: New file.
libstdc++-v3/ChangeLog
2020-06-21 David Edelsohn <dje.gcc@gmail.com>
* Makefile.am (tmake_file): Build and install AIX-style FAT libraries.
* Makefile.in: Regenerate.
* configure.ac (tmake_file): Substitute.
* configure: Regenerate.
* configure.host (aix*): Define tmake_file.
* config/os/aix/t-aix: New file.
libatomic/ChangeLog
2020-06-21 David Edelsohn <dje.gcc@gmail.com>
* Makefile.am (tmake_file): Build and install AIX-style FAT libraries.
* Makefile.in: Regenerate.
* configure.ac (tmake_file): Substitute.
* configure: Regenerate.
* configure.tgt (powerpc-ibm-aix*): Define tmake_file.
* config/t-aix: New file.
libgfortran/ChangeLog
2020-06-21 David Edelsohn <dje.gcc@gmail.com>
* Makefile.am (tmake_file): Build and install AIX-style FAT libraries.
* Makefile.in: Regenerate.
* configure.ac (tmake_file): Substitute.
* configure: Regenerate.
* configure.host: Add system configury stanza. Define tmake_file.
* config/t-aix: New file.
P2113 from the last C++ meeting clarified that we only compare constraints
on functions or function templates that have equivalent template parameters
and function parameters.
I'm not currently implementing the complicated handling of reversed
comparison operators here; thinking about it now, it seems like a lot of
complexity to support a very weird usage. If I write two similar comparison
operators to be distinguished by their constraints, why would I write one
reversed? If they're two unrelated operators, they're very unlikely to be
similar enough for the complexity to help. I've started a discussion on the
committee reflector about changing these rules.
This change breaks some greedy_ops tests in libstdc++ that were relying on
comparing constraints on unrelated templates, which seems pretty clearly
wrong, so I'm removing those tests for now.
gcc/cp/ChangeLog:
* call.c (joust): Only compare constraints for non-template
candidates with matching parameters.
* pt.c (tsubst_pack_expansion): Fix getting a type parameter
pack.
(more_specialized_fn): Only compare constraints for candidates with
matching parameters.
gcc/testsuite/ChangeLog:
* g++.dg/cpp2a/concepts-return-req1.C: Expect error.
* g++.dg/cpp2a/concepts-p2113a.C: New test.
* g++.dg/cpp2a/concepts-p2113b.C: New test.
libstdc++-v3/ChangeLog:
* testsuite/24_iterators/move_iterator/rel_ops_c++20.cc:
Remove greedy_ops tests.
* testsuite/24_iterators/reverse_iterator/rel_ops_c++20.cc:
Remove greedy_ops tests.
A small tweak to the implementation of __includes, which in my
application saves 20% of the running time. I noticed it because using
range-v3 was giving unexpected performance gains.
Some of the gain comes from pulling the 2 calls ++__first1 out of the
condition so there is just one call. And most of the gain comes from
replacing the resulting
if (__comp(__first1, __first2))
;
else
++__first2;
with
if (!__comp(__first1, __first2))
++__first2;
I was very surprised that the code ended up being so different for such
a change, and I still don't really understand where the extra time is
going...
Anyway, while I blame the compiler for not generating very good code
with the current implementation, I believe the change can be seen as a
simplification.
libstdc++-v3/ChangeLog:
* include/bits/stl_algo.h (__includes): Simplify the code.
The attached patch changes the code generated for
std::optional<std::array<int,1024>>f(){return{};}
from
movq $0, (%rdi)
movq %rdi, %r8
leaq 8(%rdi), %rdi
xorl %eax, %eax
movq $0, 4084(%rdi)
movq %r8, %rcx
andq $-8, %rdi
subq %rdi, %rcx
addl $4100, %ecx
shrl $3, %ecx
rep stosq
movq %r8, %rax
or with different tuning
subq $8, %rsp
movl $4100, %edx
xorl %esi, %esi
call memset
addq $8, %rsp
to the much shorter
movb $0, 4096(%rdi)
movq %rdi, %rax
i.e. the same as the nullopt constructor.
The constructor was already non-trivial, so we don't lose that. It passes the
testsuite without regression, but there is no new testcase to verify the
better codegen.
libstdc++-v3/ChangeLog:
* include/std/optional (optional()): Explicitly define it.
The std::__uninitialized_default_n algorithm used by std::vector creates
an initial object as a local variable then copies that into the
destination range. If the object is too large for the stack this
crashes. We should create the first object directly into the
destination and then copy it from there.
This doesn't fix the bug for C++98, because in that case the initial
value is created as a default argument of the vector constructor i.e. in
the user's code, not inside libstdc++. We can't prevent that.
PR libstdc++/94540
* include/bits/stl_uninitialized.h (__uninitialized_default_1<true>):
Construct the first value at *__first instead of on the stack.
(__uninitialized_default_n_1<true>): Likewise.
Improve comments on several of the non-standard algorithms.
* testsuite/20_util/specialized_algorithms/uninitialized_default/94540.cc:
New test.
* testsuite/20_util/specialized_algorithms/uninitialized_default_n/94540.cc:
New test.
* testsuite/20_util/specialized_algorithms/uninitialized_value_construct/94540.cc:
New test.
* testsuite/20_util/specialized_algorithms/uninitialized_value_construct_n/94540.cc:
New test.
* testsuite/23_containers/vector/cons/94540.cc: New test.
In my recent r11-1460 commit the tests had been "improved" before
commit, and no longer exercised the code paths changed by the patch.
This restores what I originally tested, so that the tests fail before
the r11-1460 change and pass after it.
* testsuite/20_util/specialized_algorithms/uninitialized_default_n/sizes.cc:
Replace Value type with int so trivial code path is used.
* testsuite/20_util/specialized_algorithms/uninitialized_value_construct_n/sizes.cc:
Likewise.
