This removes the complicated std::boolean concept, as agreed in Prague.

	* include/bits/ranges_algo.h (__find_fn, __find_first_of_fn)
	(__adjacent_find_fn): Cast result of predicate to bool.
	* include/std/concepts (__boolean): Remove.
	(__detail::__boolean_testable_impl, __detail::__boolean_testable): Add
	new helper concepts.
	(__detail::__weakly_eq_cmp_with, totally_ordered, totally_ordered_with)
	(predicate): Use __boolean_testable instead of boolean.
	* libsupc++/compare (__detail::__partially_ordered, _Synth3way):
	Likewise.

This defines ranges::ssize as approved in Prague. It's unclear what is
supposed to happen for types for which range_difference_t is not a valid
type. I've assumed they are not meant to be usable with ranges::ssize,
despite being usable with ranges::size.

	* include/bits/range_access.h (_SSize, ssize): Define for C++20.
	* testsuite/std/ranges/access/ssize.cc: New test.

Implement this change for C++20 that was just approved in Prague.

	P1956R1 On the names of low-level bit manipulation functions
	* include/bits/hashtable_policy.h: Update comment.
	* include/std/bit (__ispow2, __ceil2, __floor2, __log2p1): Rename.
	(ispow2, ceil2, floor2, log2p1): Likewise.
	(__cpp_lib_int_pow2): Add feature test macro.
	* include/std/charconv (__to_chars_len_2): Adjust use of __log2p1.
	* include/std/memory (assume_aligned): Adjust use of ispow2.
	* include/std/version (__cpp_lib_int_pow2): Add.
	* libsupc++/new_opa.cc: Adjust use of __ispow2.
	* src/c++17/memory_resource.cc: Likewise, and for __ceil2 and __log2p1.
	* testsuite/17_intro/freestanding.cc: Adjust use of ispow2.
	* testsuite/26_numerics/bit/bit.pow.two/ceil2.cc: Rename to ...
	* testsuite/26_numerics/bit/bit.pow.two/bit_ceil.cc: ... here.
	* testsuite/26_numerics/bit/bit.pow.two/ceil2_neg.cc: Rename to ...
	* testsuite/26_numerics/bit/bit.pow.two/bit_ceil_neg.cc: ... here.
	* testsuite/26_numerics/bit/bit.pow.two/floor2.cc: Rename to ...
	* testsuite/26_numerics/bit/bit.pow.two/bit_floor.cc: ... here.
	* testsuite/26_numerics/bit/bit.pow.two/log2p1.cc: Rename to ...
	* testsuite/26_numerics/bit/bit.pow.two/bit_width.cc: ... here.
	* testsuite/26_numerics/bit/bit.pow.two/ispow2.cc: Rename to ...
	* testsuite/26_numerics/bit/bit.pow.two/has_single_bit.cc: ... here.

    The code generated by this test changed shortly after
    this test was committed, and we didn't get back to
    updating the scan-assembler statements to match.
    Until now.

[testsuite]
    * gcc.target/powerpc/fold-vec-extract-longlong.p8.c: Correct
    number of expected insns.

This header is intentionally valid in C++14 mode, because no conforming
C++14 program will try to include <charconv> and so it's OK to add new
(non-reserved in C++14) names to namespace std. However, other headers
must not include <charconv> transitively prior to C++17, so that we
don't add those non-reserved names without the user requesting it.

This adds a comment to the header explaining that.

	* include/std/charconv: Add comment.

In C++20 <memory> depends on <bits/ranges_unitialized.h> which
depends on <bits/random.h> just for a single concept. Including
<bits/random.h> also requires including <cmath>, which is huge due to
the C++17 special functions.

This change moves the concept to the <bits/uniform_int_dist.h> internal
header that exists so that <bits/stl_algobase.h> doesn't need to include
<bits/random.h>.

	PR libstdc++/92546 (partial)
	* include/bits/random.h (uniform_random_bit_generator): Move definition
	to <bits/uniform_int_dist.h>.
	* include/bits/ranges_algo.h: Include <bits/uniform_int_dist.h> instead
	of <bits/random.h>.
	* include/bits/ranges_algobase.h: Do not include <cmath>.
	* include/bits/uniform_int_dist.h (uniform_random_bit_generator):
	Move here.
	* include/std/ranges: Do not include <limits>.
	* testsuite/26_numerics/random/pr60037-neg.cc: Adjust dg-error lineno.

Many uses of std::numeric_limits in C++17 and C++20 features only really
need the min(), max() and digits constants for integral types. By adding
__detail::__int_limits we can avoid including the whole <limits> header.

The <limits> header isn't especially large, but avoiding it still gives
small savings in compilation time and memory usage for the compiler.

There are also C++11 features that could benefit from this change (e.g.
<bits/hashtable_policy.h> and <bits/uniform_int_dist.h>) but I won't
change those until stage 1.

The implementation of __int_limits assumes two's complement integers,
which is true for all targets supported by GCC.

	PR libstdc++/92546 (partial)
	* include/Makefile.am: Add new header.
	* include/Makefile.in: Regenerate.
	* include/bits/int_limits.h: New header.
	* include/bits/parse_numbers.h (__select_int::_Select_int): Replace
	numeric_limits with __detail::__int_limits.
	* include/std/bit (__rotl, __rotr, __countl_zero, __countl_one)
	(__countr_zero, __countr_one, __popcount, __ceil2, __floor2, __log2p1):
	Likewise.
	* 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 (in_range): Likewise.
	* testsuite/20_util/integer_comparisons/in_range_neg.cc: Adjust for
	extra error about incomplete type __int_limits<bool>.
	* testsuite/26_numerics/bit/bit.count/countl_one.cc: Include <limits>.
	* testsuite/26_numerics/bit/bit.count/countl_zero.cc: Likewise.
	* testsuite/26_numerics/bit/bit.count/countr_one.cc: Likewise.
	* testsuite/26_numerics/bit/bit.count/countr_zero.cc: Likewise.
	* testsuite/26_numerics/bit/bit.count/popcount.cc: Likewise.
	* testsuite/26_numerics/bit/bit.pow.two/ceil2_neg.cc: Likewise.
	* testsuite/26_numerics/bit/bit.pow.two/ceil2.cc: Likewise.
	* testsuite/26_numerics/bit/bit.pow.two/floor2.cc: Likewise.
	* testsuite/26_numerics/bit/bit.pow.two/ispow2.cc: Likewise.
	* testsuite/26_numerics/bit/bit.pow.two/log2p1.cc: Likewise.
	* testsuite/26_numerics/bit/bit.rotate/rotl.cc: Likewise.
	* testsuite/26_numerics/bit/bit.rotate/rotr.cc: Likewise.

	* python/libstdcxx/v6/printers.py (StdCmpCatPrinter.to_string): Update
	value for partial_ordering::unordered.

	* include/bits/iterator_concepts.h (indirectly_copyable_storable): Add
	const-qualified expression variations.
	* include/std/concepts (copyable): Likewise.

	* include/std/type_traits (__is_standard_integer): New helper trait.
	* include/std/utility (cmp_equal, cmp_not_equal, cmp_less, cmp_greater)
	(cmp_less_equal, cmp_greater_equal, in_range): Define for C++20.
	* include/std/version (__cpp_lib_integer_comparison_functions): Define.
	* testsuite/20_util/integer_comparisons/1.cc: New test.
	* testsuite/20_util/integer_comparisons/2.cc: New test.
	* testsuite/20_util/integer_comparisons/equal.cc: New test.
	* testsuite/20_util/integer_comparisons/equal_neg.cc: New test.
	* testsuite/20_util/integer_comparisons/greater_equal.cc: New test.
	* testsuite/20_util/integer_comparisons/greater_equal_neg.cc: New test.
	* testsuite/20_util/integer_comparisons/greater_neg.cc: New test.
	* testsuite/20_util/integer_comparisons/in_range.cc: New test.
	* testsuite/20_util/integer_comparisons/in_range_neg.cc: New test.
	* testsuite/20_util/integer_comparisons/less.cc: New test.
	* testsuite/20_util/integer_comparisons/less_equal.cc: New test.
	* testsuite/20_util/integer_comparisons/less_equal_neg.cc: New test.
	* testsuite/20_util/integer_comparisons/less_neg.cc: New test.
	* testsuite/20_util/integer_comparisons/not_equal.cc: New test.
	* testsuite/20_util/integer_comparisons/not_equal_neg.cc: New test.

	PR ipa/93760
	* ipa-devirt.c (odr_types_equivalent_p): Fix grammar.
	PR ipa/93760
	* g++.dg/lto/odr-8_1.C: Fix grammar.

	PR translation/93755
	* config/rs6000/rs6000.c (rs6000_option_override_internal):
	Fix double quotes.

	PR other/93756
	* config/rx/elf.opt: Fix typo.
	PR other/93756
	* src/std/algorithm/iteration.d: Fix typo.

This makes sure to not promote diagnostics about unrecognized -Wno-
options to errors and make the intent of the diagnostic clearer.

2020-02-17  Richard Biener  <rguenther@suse.de>

	PR c/86134
	* opts-global.c (print_ignored_options): Use inform and
	amend message.

	* gcc.dg/pr86134.c: New testcase.
	* gcc.dg/pr28322-2.c: Adjust.

There have been various ICEs with -fanalyzer involving unhandled tree
codes in region_model::get_lvalue_1; PR analyzer/93388 reports various
others e.g. for IMAGPART_EXPR, REALPART_EXPR, and VIEW_CONVERT_EXPR seen
when running the testsuite with -fanalyzer forcibly enabled.

Whilst we could implement lvalue-handling in the region model for every
tree code, for some of these we're straying far from my primary goal for
GCC 10 of implementing a double-free checker for C.

This patch implements a fallback for unimplemented tree codes: create a
dummy region, but mark the new state as being invalid, and stop
exploring state along this path.  It also implements VIEW_CONVERT_EXPR.

Doing so fixes the ICEs, whilst effectively turning off the analyzer
along code paths that use such tree codes.  Hopefully this compromise
is sensible for GCC 10.

gcc/analyzer/ChangeLog:
	PR analyzer/93388
	* engine.cc (impl_region_model_context::on_unknown_tree_code):
	New.
	(exploded_graph::get_or_create_node): Reject invalid states.
	* exploded-graph.h
	(impl_region_model_context::on_unknown_tree_code): New decl.
	(point_and_state::point_and_state): Assert that the state is
	valid.
	* program-state.cc (program_state::program_state): Initialize
	m_valid to true.
	(program_state::operator=): Copy m_valid.
	(program_state::program_state): Likewise for move constructor.
	(program_state::print): Print m_valid.
	(program_state::dump_to_pp): Likewise.
	* program-state.h (program_state::m_valid): New field.
	* region-model.cc (region_model::get_lvalue_1): Implement the
	default case by returning a new symbolic region and calling
	the context's on_unknown_tree_code, rather than issuing an
	internal_error.  Implement VIEW_CONVERT_EXPR.
	* region-model.h (region_model_context::on_unknown_tree_code): New
	vfunc.
	(test_region_model_context::on_unknown_tree_code): New.

gcc/testsuite/ChangeLog:
	PR analyzer/93388
	* gcc.dg/analyzer/torture/20060625-1.c: New test.
	* gcc.dg/analyzer/torture/pr51628-30.c: New test.
	* gcc.dg/analyzer/torture/pr59037.c: New test.

This patch improves the wording of the state-transition event (1) in
the -Wanalyzer-null-dereference diagnostic for:

void test (void)
{
  int *p = NULL;
  *p = 1;
}

taking the path description from:

  ‘test’: events 1-2
    |
    |    5 |   int *p = NULL;
    |      |        ^
    |      |        |
    |      |        (1) assuming ‘p’ is NULL
    |    6 |   *p = 1;
    |      |   ~~~~~~
    |      |      |
    |      |      (2) dereference of NULL ‘p’
    |

to:

  ‘test’: events 1-2
    |
    |    5 |   int *p = NULL;
    |      |        ^
    |      |        |
    |      |        (1) ‘p’ is NULL
    |    6 |   *p = 1;
    |      |   ~~~~~~
    |      |      |
    |      |      (2) dereference of NULL ‘p’
    |

since the "assuming" at (1) only makes sense for state transitions
due to comparisons, not for assignments.

gcc/analyzer/ChangeLog:
	* sm-malloc.cc (malloc_diagnostic::describe_state_change): For
	transition to the "null" state, only say "assuming" when
	transitioning from the "unchecked" state.

gcc/testsuite/ChangeLog:
	* gcc.dg/analyzer/malloc-1.c (test_48): New.

gcc/analyzer/ChangeLog:
	* diagnostic-manager.h (diagnostic_manager::get_saved_diagnostic):
	Add const overload.
	* engine.cc (exploded_node::dump_dot): Dump saved_diagnostics.
	* exploded-graph.h (exploded_graph::get_diagnostic_manager): Add
	const overload.

As PR93047 said, __builtin_apply/__builtin_return does not work well with
-frename-registers.  This is caused by return register(e.g. r3) is used to
rename another register, before return register is stored to stack.
This patch fix this issue by emitting clobber for those egisters which
maybe changed by untyped call.

gcc/
2020-02-17  Jiufu Guo  <guojiufu@linux.ibm.com>

	PR target/93047
	* config/rs6000/rs6000.md (untyped_call): Add emit_clobber.

gcc/testsuite
2020-02-17  Jiufu Guo  <guojiufu@linux.ibm.com>

	PR target/93047
	* gcc.dg/torture/stackalign/builtin-return-2.c: New test case.

	PR target/93743
	* config/i386/i386.md (atan2xf3): Swap operands 1 and 2.
	(atan2<mode>3): Update operand order in the call to gen_atan2xf3.

testsuite/ChangeLog:

	PR target/93743
	* gcc.target/i386/pr93743.c : New test.

This makes it possible to use gccgo to bootstrap Go 1.14.
If we don't install this, gccgo can't compile the sort package.

Fixes GCC PR go/93679

Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/219617

	* ztest.c (test_large): Update file to current libgo test file.

This avoids instantiating dead code when the true branch of the constexpr if is
taken.

libstdc++-v3/ChangeLog:

	* include/bits/ranges_algo.h (__lexicographical_compare_fn::operator()):
	Move code after an early exit constexpr if to under an else branch.
	* include/bits/ranges_algobase.h (__equal_fn::operator()): Likewise.

A small improvement for an error in build_user_type_conversion_1:
instead of

array-init1.C:11:1: error: conversion from ‘long int’ to ‘A’ is ambiguous
   11 | };
      | ^

we will print

array-init1.C:8:3: error: conversion from ‘long int’ to ‘A’ is ambiguous
    8 |   0L,
      |   ^~

2020-02-12  Marek Polacek  <polacek@redhat.com>

	PR c++/93710 - poor diagnostic for array initializer.
	* call.c (build_user_type_conversion_1): Use cp_expr_loc_or_input_loc
	for an error call.

	* g++.dg/diagnostic/array-init1.C: New test.

It's probably past time for this, but definitely now that we're done with
the final committee meeting of C++20.  This patch only adds the option and
adjusts the testsuite to recognize it; more extensive changes can wait for
the published standard.

gcc/ChangeLog
2020-02-15  Jason Merrill  <jason@redhat.com>

	* doc/invoke.texi (C Dialect Options): Add -std=c++20.

gcc/c-family/ChangeLog
2020-02-15  Jason Merrill  <jason@redhat.com>

	* c.opt: Add -std=c++20.

gcc/testsuite/ChangeLog
2020-02-15  Jason Merrill  <jason@redhat.com>

	* lib/target-supports.exp (check_effective_target_c++2a_only): Also
	look for -std=*++20.
	(check_effective_target_concepts): Use check_effective_target_c++2a.

Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/218017

Otherwise we can easily run out of stack space for threads.

The user can still override by setting GOMAXPROCS.

Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/219278

libstdc++-v3/ChangeLog:

	* include/bits/ranges_algo.h: Adjust whitespace and formatting.
	* include/bits/ranges_algobase.h: Likewise.
	* include/bits/ranges_uninitialized.h: Likewise.

This is the standard way to inhibit ADL for these entities, which is required as
per [algorithms.requirements] p2 and [specialized.algorithms] p4.  The
conversion was done mostly mechanically with a custom Vim macro.

libstdc++-v3/ChangeLog:

	* include/bits/ranges_algo.h: (adjacent_find, all_of, any_of,
	binary_search, copy_if, count, count_if, equal_range, find, find_end,
	find_first_of, find_if, find_if_not, for_each, generate, generate_n,
	includes, inplace_merge, is_heap, is_heap_until, is_partitioned,
	is_permutation, is_sorted, is_sorted_until, lexicographical_compare,
	lower_bound, make_heap, max, max_element, merge, min, min_element,
	minmax, minmax_element, mismatch, next_permutation, none_of,
	nth_element, partial_sort, partial_sort_copy, partition, partition_copy,
	partition_point, pop_heap, prev_permutation, push_heap, remove,
	remove_copy, remove_copy_if, remove_if, replace, replace_copy,
	replace_copy_if, replace_if, reverse, reverse_copy, rotate, rotate_copy,
	search, search_n, set_difference, set_intersection,
	set_symmetric_difference, set_union, shuffle, sort, sort_heap,
	stable_partition, stable_sort, swap_ranges, transform, unique,
	unique_copy, upper_bound): Convert into function objects.
	* include/bits/ranges_algobase.h: (equal, copy, move, copy_n, fill_n,
	fill, move_backward, copy_backward): Likewise.
	* include/bits/ranges_uninitialized.h (uninitialized_default_construct,
	uninitialized_default_construct_n, uninitialized_value_construct,
	uninitialized_value_construct_n, uninitialized_copy,
	uninitialized_copy_n, uninitialized_move, uninitialized_move_n,
	uninitialized_fill, uninitialized_fill_n, construct_at, destroy_at,
	destroy, destroy_n): Likewise.

These subroutines have only a single call site, so it might be best and simplest
to eliminate them before we convert the algos into function objects.

libstdc++-v3/ChangeLog:

	* include/bits/ranges_algo.h (ranges::__find_end): Fold into ...
	(ranges::find_end): ... here.
	(ranges::__lexicographical_compare): Fold into ...
	(ranges::lexicographical_compare): ... here.
	* include/bits/ranges_algobase.h (ranges::__equal): Fold into ...
	(ranges::equal): ... here.

	PR c++/68061
	* g++.dg/concepts/attrib1.C: New.

find_template_parameters needs to find the mention of T in the lambda.
Fixing that leaves this as a hard error, which may be surprising but is
consistent with lambdas in other SFINAE contexts like template argument
deduction.

gcc/cp/ChangeLog
2020-02-15  Jason Merrill  <jason@redhat.com>

	PR c++/92556
	* pt.c (any_template_parm_r): Look into lambda body.

gcc/cp/ChangeLog
2020-02-15  Jason Merrill  <jason@redhat.com>

	PR c++/92583
	* pt.c (any_template_parm_r): Remove CONSTRUCTOR handling.

     PR c++/90764
     * g++.dg/cpp1z/class-deduction69.C: New.

As the following testcases show (the first one reported, last two
found by code inspection), we need to disallow side-effects
in simplifications that turn some unconditional expression into conditional
one.  From my little understanding of genmatch.c, it is able to
automatically disallow side effects if the same operand is used multiple
times in the match pattern, maybe if it is used multiple times in the
replacement pattern, and if it is used in conditional contexts in the match
pattern, could it be taught to handle this case too?  If yes, perhaps
just the first hunk could be usable for 8/9 backports (+ the testcases).

2020-02-15  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/93744
	* match.pd (((m1 >/</>=/<= m2) * d -> (m1 >/</>=/<= m2) ? d : 0,
	A - ((A - B) & -(C cmp D)) -> (C cmp D) ? B : A,
	A + ((B - A) & -(C cmp D)) -> (C cmp D) ? B : A): For GENERIC, make
	sure @2 in the first and @1 in the other patterns has no side-effects.

	* gcc.c-torture/execute/pr93744-1.c: New test.
	* gcc.c-torture/execute/pr93744-2.c: New test.
	* gcc.c-torture/execute/pr93744-3.c: New test.

Now that this feature has been approved for C++20 we can define the
macro to the official value.

	* include/bits/erase_if.h (__cpp_lib_erase_if): Define to 202002L.
	* include/std/deque: Likewise.
	* include/std/forward_list: Likewise.
	* include/std/list: Likewise.
	* include/std/string: Likewise.
	* include/std/vector: Likewise.
	* include/std/version: Likewise.
	* testsuite/23_containers/deque/erasure.cc: Test for new value.
	* testsuite/23_containers/forward_list/erasure.cc: Likewise.
	* testsuite/23_containers/list/erasure.cc: Likewise.
	* testsuite/23_containers/map/erasure.cc: Likewise.
	* testsuite/23_containers/set/erasure.cc: Likewise.
	* testsuite/23_containers/unordered_map/erasure.cc: Likewise.
	* testsuite/23_containers/unordered_set/erasure.cc: Likewise.
	* testsuite/23_containers/vector/erasure.cc: Likewise.

	* include/bits/random.h (uniform_random_bit_generator): Require min()
	and max() to be constant expressions and min() to be less than max().
	* testsuite/26_numerics/random/concept.cc: Check additional cases.
	* testsuite/26_numerics/random/pr60037-neg.cc: Adjust dg-error lineno.

2020-02-15  David Malcolm  <dmalcolm@redhat.com>
	    Bernd Edlinger  <bernd.edlinger@hotmail.de>

	PR 87488
	PR other/93168
	* config.in (DIAGNOSTICS_URLS_DEFAULT): New define.
	* configure.ac (--with-diagnostics-urls): New configuration
	option, based on --with-diagnostics-color.
	(DIAGNOSTICS_URLS_DEFAULT): New define.
	* config.h: Regenerate.
	* configure: Regenerate.
	* diagnostic.c (diagnostic_urls_init): Handle -1 for
	DIAGNOSTICS_URLS_DEFAULT from configure-time
	--with-diagnostics-urls=auto-if-env by querying for a GCC_URLS
	and TERM_URLS environment variable.
	* diagnostic-url.h (diagnostic_url_format): New enum type.
	(diagnostic_urls_enabled_p): rename to...
	(determine_url_format): ... this, and change return type.
	* diagnostic-color.c (parse_env_vars_for_urls): New helper function.
	(auto_enable_urls): Disable URLs on xfce4-terminal, gnome-terminal,
	the linux console, and mingw.
	(diagnostic_urls_enabled_p): rename to...
	(determine_url_format): ... this, and adjust.
	* pretty-print.h (pretty_printer::show_urls): rename to...
	(pretty_printer::url_format): ... this, and change to enum.
	* pretty-print.c (pretty_printer::pretty_printer,
	pp_begin_url, pp_end_url, test_urls): Adjust.
	* doc/install.texi (--with-diagnostics-urls): Document the new
	configuration option.
	(--with-diagnostics-color): Document the existing interaction
	with GCC_COLORS better.
	* doc/invoke.texi (-fdiagnostics-urls): Add GCC_URLS and TERM_URLS
	vindex reference.  Update description of defaults based on the above.
	(-fdiagnostics-color): Update description of how -fdiagnostics-color
	interacts with GCC_COLORS.

gcc/ChangeLog:

	* doc/extend.texi (attribute alias): Mention type requirement.
	(attribute weak): Same.
	(attribute weakref): Correct invalid example.