The "persistent" attribute is used for variables that are initialized
by the program loader, but are not initialized by the runtime startup
code. "persistent" variables are placed in a non-volatile area of
memory, which allows their value to "persist" between processor resets.

gcc/c-family/ChangeLog:

	* c-attribs.c (handle_special_var_sec_attribute): New.
	(handle_noinit_attribute): Remove.
	(attr_noinit_exclusions): Rename to...
	(attr_section_exclusions): ...this, and add "persistent" attribute
	exclusion.
	(c_common_attribute_table): Add "persistent" attribute.

gcc/ChangeLog:

	* doc/extend.texi (Common Variable Attributes): Document the
	"persistent" variable attribute.
	* doc/sourcebuild.texi (Effective-Target Keywords): Document
	the "persistent" effective target keyword.
	* tree.h (DECL_PERSISTENT_P): Define.
	* varasm.c (bss_initializer_p): Return false for a
	DECL_PERSISTENT_P decl initialized to zero.
	(default_section_type_flags): Handle the ".persistent" section.
	(default_elf_select_section): Likewise.
	(default_unique_section): Likewise.

gcc/testsuite/ChangeLog:

	* gcc.c-torture/execute/noinit-attribute.c: Moved to...
	* c-c++-common/torture/attr-noinit-main.inc: ...here.
	* lib/target-supports.exp (check_effective_target_persistent): New.
	* c-c++-common/torture/attr-noinit-1.c: New test.
	* c-c++-common/torture/attr-noinit-2.c: New test.
	* c-c++-common/torture/attr-noinit-3.c: New test.
	* c-c++-common/torture/attr-noinit-invalid.c: New test.
	* c-c++-common/torture/attr-persistent-1.c: New test.
	* c-c++-common/torture/attr-persistent-2.c: New test.
	* c-c++-common/torture/attr-persistent-3.c: New test.
	* c-c++-common/torture/attr-persistent-invalid.c: New test.
	* c-c++-common/torture/attr-persistent-main.inc: New test.

Attribute handlers may want to examine DECL_INITIAL for a decl, to
validate the attribute being applied. For C++, DECL_INITIAL is currently
not set until cp_finish_decl, by which time attribute validation has
already been performed.

For msp430-elf this causes the "persistent" attribute to always be
rejected for C++, since DECL_INITIAL must be non-null for the
attribute to be applied to a decl.

This patch ensures DECL_INITIAL is set for initialized decls early in
start_decl, before attribute handlers run. This allows the
initialization status of the decl to be examined by the handlers.
DECL_INITIAL must be restored to it's initial value after attribute
validation is performed, so as to not interfere with later decl
processing.

gcc/cp/ChangeLog:

	* decl.c (start_decl): Set DECL_INITIAL for initialized decls
	before attribute processing.

gcc/testsuite/ChangeLog:

	* gcc.target/msp430/data-attributes-2.c: Adjust test.
	* g++.target/msp430/data-attributes.C: New test.
	* g++.target/msp430/msp430.exp: New test.

Variables with the "noinit" attribute are ignored at -O0 because they
are treated like a regular bss variable and placed in the .bss section.

With -fdata-sections they are ignored because they are not handled in
resolve_unique_section.

gcc/ChangeLog:

	* tree.h (DECL_NOINIT_P): Define.
	* varasm.c (DECL_NOINIT_P): Check DECL_NOINIT_P before using
	unnamed bss/lcomm sections for bss_initializer variables.
	(default_elf_select_section): Use DECL_NOINIT_P instead of
	looking up attribute for .noinit section selection.
	(default_unique_section): Check DECL_NOINIT_P for .noinit
	section selection.

gcc/testsuite/ChangeLog:

	* gcc.c-torture/execute/noinit-attribute.c: Don't override
	optimization options set by torture test harness.
	* lib/target-supports.exp (check_effective_target_noinit): Adjust
	comment formatting.

Document how to configure using asan (bootstrap-asan option to the
--with-build-config configure argument).

gcc/ChangeLog:

	* doc/install.texi: Document bootstrap-asan option.

Some tests force -mcpu=cortex-mXX but do not add -mthumb, causing
errors if GCC is not configured to default to Thumb code
(--with-mode=thumb):
cc1: error: target CPU does not support ARM mode

This patch adds -mthumb where relevant.

2020-11-23  Christophe Lyon  <christophe.lyon@linaro.org>

	gcc/testsuite/
	* gcc.target/arm/cortex-m55-nodsp-flag-hard.c: Add -mthumb.
	* gcc.target/arm/cortex-m55-nodsp-flag-softfp.c: Likewise.
	* gcc.target/arm/cortex-m55-nodsp-nofp-flag-softfp.c: Likewise.
	* gcc.target/arm/cortex-m55-nofp-flag-hard.c: Likewise.
	* gcc.target/arm/cortex-m55-nofp-flag-softfp.c: Likewise.
	* gcc.target/arm/cortex-m55-nofp-nomve-flag-softfp.c: Likewise.
	* gcc.target/arm/cortex-m55-nomve-flag-hard.c: Likewise.
	* gcc.target/arm/cortex-m55-nomve-flag-softfp.c: Likewise.
	* gcc.target/arm/cortex-m55-nomve.fp-flag-hard.c: Likewise.
	* gcc.target/arm/cortex-m55-nomve.fp-flag-softfp.c: Likewise.
	* gcc.target/arm/mve/intrinsics/pr97327.c: Likewise.

When adding the verify_type_context target hook, I'd missed
a site that needs to check an array element type.

gcc/cp/
	PR c++/97904
	* pt.c (tsubst): Use verify_type_context to check the type
	of an array element.

gcc/testsuite/
	PR c++/97904
	* g++.dg/ext/sve-sizeless-1.C: Add more template tests.
	* g++.dg/ext/sve-sizeless-2.C: Likewise.

Generate special double mode sequence also for TImode on 64bit targets.

2020-11-22  Uroš Bizjak  <ubizjak@gmail.com>

	PR target/97873

gcc/
	* config/i386/i386.md (abs<mode>2): Use SWI48DWI mode iterator.
	(*abs<dwi>2_doubleword): Use DWIH mode iterator.

	(<maxmin:code><mode>3): Use SWI48DWI mode iterator.
	(*<maxmin:code><dwi>3_doubleword): Use DWIH mode iterator.

gcc/testsuite/
	* gcc.target/i386/pr97873-2.c: New test.

gcc/
	* config/h8300/addsub.md: Turn existing patterns into
	define_insn_and_split style patterns where the splitter
	adds a clobber of the condition code register.  Drop "cc"
	attribute.  Add _clobber_flags patterns to match output of
	the splitters.
	(add<mod>3_incdec): Remove pattern
	(adds/subs splitter): Only run before reload.
	* config/h8300/bitfield.md: Turn existing patterns into
	define_insn_and_split style patterns where the splitter
	adds a clobber of the condition code register.  Drop "cc"
	attribute.  Add _clobber_flags patterns to match output
	of the splitters.
	(cstoreqi4, cstorehi4, cstoresi4): Comment out
	(*bstzhireg, *cmpstz, *bstz, *bistz, *cmpcondset): Likewise
	(*condbset, *cmpcondbclr, *condbclr): Likewise.
	(*cmpcondbsetreg, *condbsetreg, *cmpcondbclrreg): Likewise.
	(*condbclrreg): Likewise.
	* config/h8300/combiner.md: Turn existing patterns into
	define_insn_and_split style patterns where the splitter
	adds a clobber of the condition code register.  Drop "cc"
	attribute.  Add _clobber_flags patterns to match output of
	the splitters.  Add appropriate CC register clobbers to
	existing splitters.
	(*addsi3_and_r_1): Disable for now.
	(*addsi3_and_not_r_1, bit-test branches): Likewise.
	* config/h8300/divmod.md: Turn existing patterns into
	define_insn_and_split style patterns where the splitter
	adds a clobber of the condition code register.  Drop "cc"
	attribute.  Add _clobber_flags patterns to match output of
	the splitters.
	* config/h8300/extensions.md: Turn existing patterns into
	define_insn_and_split style patterns where the splitter
	adds a clobber of the condition code register.  Drop "cc"
	attribute.  Add _clobber_flags patterns to match output of
	the splitters.
	* config/h8300/genmova.sh: Drop "cc" attribute from patterns.
	* config/h8300/mova.md: Drop "cc" attribute from patterns.
	* config/h8300/h8300-modes.def: Add CCZN and CCZNV modes.
	* config/h8300/h8300-protos.h (output_plussi): Update prototype.
	(compute_plussi_length): Likewise.
	(h8300_select_cc_mode): Add prototype.
	(compute_a_shift_cc): Remove prototype
	(cmpute_logical_op_cc): Likewise.
	* config/h8300/h8300.c (names_big): Add "cc" register.
	(names_extended, names_upper_extended): Likewise.
	(h8300_emit_stack_adjustment): Be more selective about setting
	RTX_FRAME_RELATED_P.
	(h8300_print_operand): Handle CCZN mode
	(h8300_select_cc_mode): New function.
	(notice_update_cc): if-0 out.  Only kept for reference purposes.
	(h8300_expand_store): Likewise.
	(h8300_binary_length): Handle new insn forms.
	(output_plussi): Add argument for NEED_FLAGS and handle that case.
	(compute_plussi_length): Likewise.
	(compute_logical_op_cc): Return integer.
	(TARGET_FLAGS_REGNUM): Define.
	* config/h8300/h8300.h (FIRST_PSEUDO_REGISTER): Bump for cc register.
	(FIXED_REGISTERS, CALL_USED_REGISTERS): Handle cc register.
	(REG_ALLOC_ORDER, REGISTER_NAMES): Likewise.
	(SELECT_CC_MODE): Define.
	* config/h8300/h8300.md: Add CC_REG.
	Do not include peepholes.md for now.
	* config/h8300/jumpcall.md (cbranchqi4): Consolidate into
	cbranch<mode>4.
	(cbranchhi4, cbranchsi4): Likewise.
	(cbranch<mode>4): New expander.
	(branch): New define_insn_and_split for use before reload.
	(branch_1, branch_1_false): New patterns to match splitter output.
	Remove code to manage cc_status.flags.
	* config/h8300/logical.md: Turn existing patterns into
	define_insn_and_split style patterns where the splitter
	adds a clobber of the condition code register.  Drop "cc"
	attribute.  Add _clobber_flags patterns to match output of
	the splitters.  Move various peepholes into this file.
	* config/h8300/movepush.md: Turn existing patterns into
	define_insn_and_split style patterns where the splitter
	adds a clobber of the condition code register.  Drop "cc"
	attribute.  Add _clobber_flags patterns to match output of
	the splitters.
	* config/h8300/multiply.md: Turn existing patterns into
	define_insn_and_split style patterns where the splitter
	adds a clobber of the condition code register.  Drop "cc"
	attribute.  Add _clobber_flags patterns to match output of
	the splitters.
	* config/h8300/other.md: Turn existing patterns into
	define_insn_and_split style patterns where the splitter
	adds a clobber of the condition code register.  Drop "cc"
	attribute.  Add _clobber_flags patterns to match output of
	the splitters.
	* config/h8300/peepholes.md: Remove peepholes that were moved
	elsewhere.
	* config/h8300/predicates.md (simple_memory_operand): New.
	* config/h8300/proepi.md: Drop "cc" attribute setting.
	* config/h8300/shiftrotate.md: Turn existing patterns into
	define_insn_and_split style patterns where the splitter
	adds a clobber of the condition code register.  Drop "cc"
	attribute.  Add _clobber_flags patterns to match output of
	the splitters.
	* config/h8300/testcompare.md: Turn existing patterns into
	define_insn_and_split style patterns where the splitter
	adds a clobber of the condition code register.  Drop "cc"
	attribute.  Add _clobber_flags patterns to match output of
	the splitters.  Disable various patterns for now.
	Move some peepholes that were previously in peepholes.md here.

When appending a character to an array, the result of that concat
assignment was not the new value of the array, similarly, when appending
an array to another array, side effects were evaluated in reverse to the
expected order of evaluation.

As of this change, the address of the left-hand side expression is
saved and re-used as the result.  Its evaluation is now also forced to
occur before the concat operation itself is called.

gcc/d/ChangeLog:

	PR d/97889
	* expr.cc (ExprVisitor::visit (CatAssignExp *)): Enforce LTR order of
	evaluation on left and right hand side expressions.

gcc/testsuite/ChangeLog:

	PR d/97889
	* gdc.dg/torture/pr97889.d: New test.

The following patch recognizes some further forms of additions with overflow
checks as shown in the testcase, in particular where the unsigned addition is
performed in a wider mode just to catch overflow with a > narrower_utype_max
check.

2020-11-22  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/95853
	* tree-ssa-math-opts.c (uaddsub_overflow_check_p): Add maxval
	argument, if non-NULL, instead look for r > maxval or r <= maxval
	comparisons.
	(match_uaddsub_overflow): Pattern recognize even other forms of
	__builtin_add_overflow, in particular when addition is performed
	in a wider type and result compared to maximum of the narrower
	type.

	* gcc.dg/pr95853.c: New test.

So I'd forgotten an important tidbit on the H8 port.  Specifically
for a branch instruction, the target label must be operand 0 for
the length computations.

This really only affects the main conditional branch pattern.
The other conditional branch patterns are split and ultimately
funnel into the main pattern.  This patch fixes the issue by
partially reverting an earlier change.  This issue didn't show up
until late in the optimization work on cc0 removal of the H8 port,
but was caught by the testsuite.  So there's no new test.

Built and regression tested H8 with this change, with and without
the cc0 removal patches.

gcc/

	* config/h8300/jumpcall.md (branch_true, branch_false): Revert
	recent change.  Ensure operand[0] is always the target label.

We have a similar code pattern in darwin-c.c to one in c-pragmas
(most likely a cut & paste) with a struct type used locally to the
TU.  With C++ we need to rename the type to avoid an ODR violation.

gcc/ChangeLog:

	* config/darwin-c.c (struct f_align_stack): Rename
	to type from align_stack to f_align_stack.
	(push_field_alignment): Likewise.
	(pop_field_alignment): Likewise.

This patch finishes the second half of -Wrange-loop-construct I promised
to implement: it warns when a loop variable in a range-based for-loop is
initialized with a value of a different type resulting in a copy.  For
instance:

  int arr[10];
  for (const double &x : arr) { ... }

where in every iteration we have to create and destroy a temporary value
of type double, to which we bind the reference.  This could negatively
impact performance.

As per Clang, this doesn't warn when the range returns a copy, hence the
glvalue_p check.

gcc/ChangeLog:

	PR c++/94695
	* doc/invoke.texi: Update the -Wrange-loop-construct description.

gcc/cp/ChangeLog:

	PR c++/94695
	* parser.c (warn_for_range_copy): Warn when the loop variable is
	initialized with a value of a different type resulting in a copy.

gcc/testsuite/ChangeLog:

	PR c++/94695
	* g++.dg/warn/Wrange-loop-construct2.C: New test.

[dcl.constexpr]/3 says that the function-body of a constexpr function
shall not contain an identifier label, but we aren't enforcing that.

This patch implements that.  Of course, we can't reject artificial
labels.

gcc/cp/ChangeLog:

	PR c++/97846
	* constexpr.c (potential_constant_expression_1): Reject
	LABEL_EXPRs that use non-artifical LABEL_DECLs.

gcc/testsuite/ChangeLog:

	PR c++/97846
	* g++.dg/cpp1y/constexpr-label.C: New test.

This invalid (?) code broke my assumption that if decl_specifiers->type
is null, there must be any type-specifiers.  Turn the assert into an if
to fix this crash.

gcc/cp/ChangeLog:

	PR c++/97881
	* parser.c (warn_about_ambiguous_parse): Only assume "int" if we
	actually saw any type-specifiers.

gcc/testsuite/ChangeLog:

	PR c++/97881
	* g++.dg/warn/Wvexing-parse9.C: New test.

The testcase uses LTO but does not include the dg-require LTO.

gcc/testsuite/ChangeLog:

	* g++.dg/debug/localclass2.C: Require LTO.

Our implementation of template lambdas incorrectly requires the optional
lambda-declarator.  This was probably required by an early draft of
generic lambdas, but now the production is [expr.prim.lambda.general]:

 lambda-expression:
    lambda-introducer lambda-declarator [opt] compound-statement
    lambda-introducer < template-parameter-list > requires-clause [opt]
	  lambda-declarator [opt] compound-statement

Therefore, we should accept the following test.

gcc/cp/ChangeLog:

	PR c++/97839
	* parser.c (cp_parser_lambda_declarator_opt): Don't require ().

gcc/testsuite/ChangeLog:

	PR c++/97839
	* g++.dg/cpp2a/lambda-generic8.C: New test.

	* tree-ssa-alias.c (ao_compare::compare_ao_refs,
	ao_compare::hash_ao_ref): Use OEP_MATCH_SIDE_EFFECTS.

When I implemented the code to detect modifying const objects in
constexpr contexts, we couldn't have constexpr destructors, so I didn't
consider them.  But now we can and that caused a bogus error in this
testcase: [class.dtor]p5 says that "const and volatile semantics are not
applied on an object under destruction.  They stop being in effect when
the destructor for the most derived object starts." so we have to clear
the TREE_READONLY flag we set on the object after the constructors have
been called to mark it as no-longer-under-construction.  In the ~Foo
call it's now an object under destruction, so don't report those errors.

gcc/cp/ChangeLog:

	PR c++/97427
	* constexpr.c (cxx_set_object_constness): New function.
	(cxx_eval_call_expression): Set new_obj for destructors too.
	Call cxx_set_object_constness to set/unset TREE_READONLY of
	the object under construction/destruction.

gcc/testsuite/ChangeLog:

	PR c++/97427
	* g++.dg/cpp2a/constexpr-dtor10.C: New test.

This fixes some UNRESOLVED tests on (at least) Solaris and Darwin, and
disables some tests that hang forever on Solaris. A proper fix is still
needed.

libstdc++-v3/ChangeLog:

	* include/bits/atomic_base.h (atomic_flag::wait): Use correct
	type for __atomic_wait call.
	* include/bits/atomic_timed_wait.h (__atomic_wait_until): Check
	_GLIBCXX_HAVE_LINUX_FUTEX.
	* include/bits/atomic_wait.h (__atomic_notify): Likewise.
	* include/bits/semaphore_base.h (_GLIBCXX_HAVE_POSIX_SEMAPHORE):
	Only define if SEM_VALUE_MAX or _POSIX_SEM_VALUE_MAX is defined.
	* testsuite/29_atomics/atomic/wait_notify/bool.cc: Disable on
	non-linux targes.
	* testsuite/29_atomics/atomic/wait_notify/generic.cc: Likewise.
	* testsuite/29_atomics/atomic/wait_notify/pointers.cc: Likewise.
	* testsuite/29_atomics/atomic_flag/wait_notify/1.cc: Likewise.
	* testsuite/29_atomics/atomic_float/wait_notify.cc: Likewise.

We now determine depnedencies across union fields correctly.

	* gcc.dg/vect/vect-35-big-array.c: Excpect 2 loops to be vectorized.
	* gcc.dg/vect/vect-35.c: Excpect 2 loops to be vectorized.

	* ipa-icf.c (sem_function::equals_wpa): Do not compare ODR type with
	-fno-devirtualize.
	(sem_item_optimizer::update_hash_by_addr_refs): Hash anonymous ODR
	types by TYPE_UID of their main variant.

After the MMA opaque mode patch goes in, we can re-enable
use of vector pair in the inline expansion of memcpy/memmove.

gcc/
	* config/rs6000/rs6000.c (rs6000_option_override_internal):
	Enable vector pair memcpy/memmove expansion.

This patch changes powerpc MMA builtins to use the new opaque
mode class and use modes OO (32 bytes) and XO (64 bytes)
instead of POI/PXI. Using the opaque modes prevents
optimization from trying to do anything with vector
pair/quad, which was the problem we were seeing with the
partial integer modes.

gcc/
	* config/rs6000/mma.md (unspec): Add assemble/extract UNSPECs.
	(movoi): Change to movoo.
	(*movpoi): Change to *movoo.
	(movxi): Change to movxo.
	(*movpxi): Change to *movxo.
	(mma_assemble_pair): Change to OO mode.
	(*mma_assemble_pair): New define_insn_and_split.
	(mma_disassemble_pair): New define_expand.
	(*mma_disassemble_pair): New define_insn_and_split.
	(mma_assemble_acc): Change to XO mode.
	(*mma_assemble_acc): Change to XO mode.
	(mma_disassemble_acc): New define_expand.
	(*mma_disassemble_acc): New define_insn_and_split.
	(mma_<acc>): Change to XO mode.
	(mma_<vv>): Change to XO mode.
	(mma_<avv>): Change to XO mode.
	(mma_<pv>): Change to OO mode.
	(mma_<apv>): Change to XO/OO mode.
	(mma_<vvi4i4i8>): Change to XO mode.
	(mma_<avvi4i4i8>): Change to XO mode.
	(mma_<vvi4i4i2>): Change to XO mode.
	(mma_<avvi4i4i2>): Change to XO mode.
	(mma_<vvi4i4>): Change to XO mode.
	(mma_<avvi4i4>): Change to XO mode.
	(mma_<pvi4i2>): Change to XO/OO mode.
	(mma_<apvi4i2>): Change to XO/OO mode.
	(mma_<vvi4i4i4>): Change to XO mode.
	(mma_<avvi4i4i4>): Change to XO mode.
	* config/rs6000/predicates.md (input_operand): Allow opaque.
	(mma_disassemble_output_operand): New predicate.
	* config/rs6000/rs6000-builtin.def:
	Changes to disassemble builtins.
	* config/rs6000/rs6000-call.c (rs6000_return_in_memory):
	Disallow __vector_pair/__vector_quad as return types.
	(rs6000_promote_function_mode): Remove function return type
	check because we can't test it here any more.
	(rs6000_function_arg): Do not allow __vector_pair/__vector_quad
	as as function arguments.
	(rs6000_gimple_fold_mma_builtin):
	Handle mma_disassemble_* builtins.
	(rs6000_init_builtins): Create types for XO/OO modes.
	* config/rs6000/rs6000-modes.def: DElete OI, XI,
	POI, and PXI modes, and create XO and OO modes.
	* config/rs6000/rs6000-string.c (expand_block_move):
	Update to OO mode.
	* config/rs6000/rs6000.c (rs6000_hard_regno_mode_ok_uncached):
	Update for XO/OO modes.
	(rs6000_rtx_costs): Make UNSPEC_MMA_XXSETACCZ cost 0.
	(rs6000_modes_tieable_p): Update for XO/OO modes.
	(rs6000_debug_reg_global): Update for XO/OO modes.
	(rs6000_setup_reg_addr_masks): Update for XO/OO modes.
	(rs6000_init_hard_regno_mode_ok): Update for XO/OO modes.
	(reg_offset_addressing_ok_p): Update for XO/OO modes.
	(rs6000_emit_move): Update for XO/OO modes.
	(rs6000_preferred_reload_class): Update for XO/OO modes.
	(rs6000_split_multireg_move): Update for XO/OO modes.
	(rs6000_mangle_type): Update for opaque types.
	(rs6000_invalid_conversion): Update for XO/OO modes.
	* config/rs6000/rs6000.h (VECTOR_ALIGNMENT_P):
	Update for XO/OO modes.
	* config/rs6000/rs6000.md (RELOAD): Update for XO/OO modes.
gcc/testsuite/
	* gcc.target/powerpc/mma-double-test.c (main): Call abort for failure.
	* gcc.target/powerpc/mma-single-test.c (main): Call abort for failure.
	* gcc.target/powerpc/pr96506.c: Rename to pr96506-1.c.
	* gcc.target/powerpc/pr96506-2.c: New test.

After building some larger codes using opaque types and some c++ codes
using opaque types it became clear I needed to go through and look for
places where opaque types and modes needed to be handled. A whole pile
of one-liners.

gcc/
	* typeclass.h: Add opaque_type_class.
	* builtins.c (type_to_class): Identify opaque type class.
	* dwarf2out.c (is_base_type): Handle opaque types.
	(gen_type_die_with_usage): Handle opaque types.
	* expr.c (count_type_elements): Opaque types should
	never have initializers.
	* ipa-devirt.c (odr_types_equivalent_p): No type-specific handling
	for opaque types is needed as it eventually checks the underlying
	mode which is what is important.
	* tree-streamer.c (record_common_node): Handle opaque types.
	* tree.c (type_contains_placeholder_1): Handle opaque types.
	(type_cache_hasher::equal): No additional comparison needed for
	opaque types.
gcc/c-family
	* c-pretty-print.c (c_pretty_printer::simple_type_specifier):
	Treat opaque types like other types.
	(c_pretty_printer::direct_abstract_declarator): Opaque types are
	supported types.
gcc/c
	* c-aux-info.c (gen_type): Support opaque types.
gcc/cp
	* error.c (dump_type): Handle opaque types.
	(dump_type_prefix): Handle opaque types.
	(dump_type_suffix): Handle opaque types.
	(dump_expr): Handle opaque types.
	* pt.c (tsubst): Allow opaque types in templates.
	(unify): Allow opaque types in templates.
	* typeck.c (structural_comptypes): Handle comparison
	of opaque types.

On macOS / Darwin, the environ variable can be used directly in the
code of an executable, but cannot be used in the code of a shared
library (i.e. libgfortran.dylib), in this case.

In such cases, the  function _NSGetEnviron should be called to get
the address of 'environ'.

libgfortran/ChangeLog:

	* intrinsics/execute_command_line.c (environ): Use
	_NSGetEnviron to get the environment pointer on Darwin.

The sanitizer is supported for at least x86_64 and Darwin20.

libsanitizer/ChangeLog:

	* configure.tgt: Allow x86_64 Darwin2x.

Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/272146

Since the test is compiled with -fno-builtin, include math.h to allow for
implementations (like the PowerPC) that have multiple versions of long double
that are selectable by switch.  Math.h could possibly switch what function
nextafterl points to.

gcc/testsuite/
2020-11-17  Michael Meissner  <meissner@linux.ibm.com>

	* gcc.dg/nextafter-2.c: Include math.h.

This patch adds support for mapping the scalar_cmp_exp_qp_* built-in functions
to handle arguments that are either TFmode or KFmode, depending on whether long
double uses the IEEE 128-bit representation (TFmode) or the IBM 128-bit
representation (KFmode).  This shows up in the float128-cmp2-runnable.c test
when long double uses the IEEE 128-bit representation.

gcc/
2020-11-20  Michael Meissner  <meissner@linux.ibm.com>

	* config/rs6000/rs6000-call.c (rs6000_expand_builtin): Add missing
	XSCMP* cases for IEEE 128-bit long double.

Add support for -
  * atomic_flag::wait/notify_one/notify_all
  * atomic::wait/notify_one/notify_all
  * counting_semaphore
  * binary_semaphore
  * latch

libstdc++-v3/ChangeLog:

	* include/Makefile.am (bits_headers): Add new header.
	* include/Makefile.in: Regenerate.
	* include/bits/atomic_base.h (__atomic_flag::wait): Define.
	(__atomic_flag::notify_one): Likewise.
	(__atomic_flag::notify_all): Likewise.
	(__atomic_base<_Itp>::wait): Likewise.
	(__atomic_base<_Itp>::notify_one): Likewise.
	(__atomic_base<_Itp>::notify_all): Likewise.
	(__atomic_base<_Ptp*>::wait): Likewise.
	(__atomic_base<_Ptp*>::notify_one): Likewise.
	(__atomic_base<_Ptp*>::notify_all): Likewise.
	(__atomic_impl::wait): Likewise.
	(__atomic_impl::notify_one): Likewise.
	(__atomic_impl::notify_all): Likewise.
	(__atomic_float<_Fp>::wait): Likewise.
	(__atomic_float<_Fp>::notify_one): Likewise.
	(__atomic_float<_Fp>::notify_all): Likewise.
	(__atomic_ref<_Tp>::wait): Likewise.
	(__atomic_ref<_Tp>::notify_one): Likewise.
	(__atomic_ref<_Tp>::notify_all): Likewise.
	(atomic_wait<_Tp>): Likewise.
	(atomic_wait_explicit<_Tp>): Likewise.
	(atomic_notify_one<_Tp>): Likewise.
	(atomic_notify_all<_Tp>): Likewise.
	* include/bits/atomic_wait.h: New file.
	* include/bits/atomic_timed_wait.h: New file.
	* include/bits/semaphore_base.h: New file.
	* include/std/atomic (atomic<bool>::wait): Define.
	(atomic<bool>::wait_one): Likewise.
	(atomic<bool>::wait_all): Likewise.
	(atomic<_Tp>::wait): Likewise.
	(atomic<_Tp>::wait_one): Likewise.
	(atomic<_Tp>::wait_all): Likewise.
	(atomic<_Tp*>::wait): Likewise.
	(atomic<_Tp*>::wait_one): Likewise.
	(atomic<_Tp*>::wait_all): Likewise.
	* include/std/latch: New file.
	* include/std/semaphore: New file.
	* include/std/version: Add __cpp_lib_semaphore and
	__cpp_lib_latch defines.
	* testsuite/29_atomics/atomic/wait_notify/bool.cc: New test.
	* testsuite/29_atomics/atomic/wait_notify/pointers.cc: Likewise.
	* testsuite/29_atomics/atomic/wait_notify/generic.cc: Liekwise.
	* testsuite/29_atomics/atomic_flag/wait_notify/1.cc: Likewise.
	* testsuite/29_atomics/atomic_float/wait_notify.cc: Likewise.
	* testsuite/29_atomics/atomic_integral/wait_notify.cc: Likewise.
	* testsuite/29_atomics/atomic_ref/wait_notify.cc: Likewise.
	* testsuite/30_threads/semaphore/1.cc: New test.
	* testsuite/30_threads/semaphore/2.cc: Likewise.
	* testsuite/30_threads/semaphore/least_max_value_neg.cc: Likewise.
	* testsuite/30_threads/semaphore/try_acquire.cc: Likewise.
	* testsuite/30_threads/semaphore/try_acquire_for.cc: Likewise.
	* testsuite/30_threads/semaphore/try_acquire_posix.cc: Likewise.
	* testsuite/30_threads/semaphore/try_acquire_until.cc: Likewise.
	* testsuite/30_threads/latch/1.cc: New test.
	* testsuite/30_threads/latch/2.cc: New test.
	* testsuite/30_threads/latch/3.cc: New test.
	* testsuite/util/atomic/wait_notify_util.h: New File.

Here, since we only mention bar<B>, we never emit debug information for it.
But we do emit debug information for H<J>::h, so we need to refer to the
debug info for bar<B>::J even though there is no bar<B>.  We deal with this
sort of thing in dwarf2out with the limbo_die_list; parentless dies like J
get attached to the CU at EOF.  But here, we were flushing the limbo list,
then generating the template argument DIE for H<J> that refers to J, which
adds J to the limbo list, too late to be flushed.  So let's flush a little
later.

gcc/ChangeLog:

	PR c++/97918
	* dwarf2out.c (dwarf2out_early_finish): flush_limbo_die_list
	after gen_scheduled_generic_parms_dies.

gcc/testsuite/ChangeLog:

	PR c++/97918
	* g++.dg/debug/localclass2.C: New test.

gcc/c-family/ChangeLog:
	* c-warn.c (warn_parm_array_mismatch): Bail on invalid redeclarations
	with fewer arguments.

gcc/testsuite/ChangeLog:
	* gcc.dg/attr-access-4.c: New test.

Reduce memory allocation in stable_sort/inplace_merge algorithms to what is needed
by the implementation.

Co-authored-by: John Chang <john.chang@samba.tv>

libstdc++-v3/ChangeLog:

	PR libstdc++/83938
	* include/bits/stl_tempbuf.h (get_temporary_buffer): Change __len
	computation in the loop to avoid truncation.
	* include/bits/stl_algo.h:
	(__inplace_merge): Take temporary buffer length from smallest range.
	(__stable_sort): Limit temporary buffer length.
	* testsuite/25_algorithms/inplace_merge/1.cc (test4): New.
	* testsuite/performance/25_algorithms/stable_sort.cc: Test stable_sort
	under different heap memory conditions.
	* testsuite/performance/25_algorithms/inplace_merge.cc: New test.

Check for the presence of _SC_NPROCESSORS_ONLN rather than using a list
of OS-specific macros to decide whether to use `sysconf' like elsewhere
across GCC sources, fixing a compilation error:

adaint.c: In function '__gnat_number_of_cpus':
adaint.c:2398:26: error: '_SC_NPROCESSORS_ONLN' undeclared (first use in this function)
 2398 |   cores = (int) sysconf (_SC_NPROCESSORS_ONLN);
      |                          ^~~~~~~~~~~~~~~~~~~~
adaint.c:2398:26: note: each undeclared identifier is reported only once for each function it appears in

at least with with VAX/NetBSD 1.6.2.

	gcc/ada/
	* adaint.c (__gnat_number_of_cpus): Check for the presence of
	_SC_NPROCESSORS_ONLN rather than a list of OS-specific macros
	to decide whether to use `sysconf'.

Disable USE_PT_GNU_EH_FRAME frame unwinder support for old OS versions,
fixing compilation errors:

.../libgcc/unwind-dw2-fde-dip.c:75:21: error: unknown type name 'Elf_Phdr'
   75 | # define ElfW(type) Elf_##type
      |                     ^~~~
.../libgcc/unwind-dw2-fde-dip.c:132:9: note: in expansion of macro 'ElfW'
  132 |   const ElfW(Phdr) *p_eh_frame_hdr;
      |         ^~~~
.../libgcc/unwind-dw2-fde-dip.c:75:21: error: unknown type name 'Elf_Phdr'
   75 | # define ElfW(type) Elf_##type
      |                     ^~~~
.../libgcc/unwind-dw2-fde-dip.c:133:9: note: in expansion of macro 'ElfW'
  133 |   const ElfW(Phdr) *p_dynamic;
      |         ^~~~
.../libgcc/unwind-dw2-fde-dip.c:165:37: warning: 'struct dl_phdr_info' declared inside parameter list will not be visible outside of this definition or declaration
  165 | _Unwind_IteratePhdrCallback (struct dl_phdr_info *info, size_t size, void *ptr)
      |                                     ^~~~~~~~~~~~
[...]

and producing a working cross-compiler at least with VAX/NetBSD 1.6.2.

	libgcc/
	* unwind-dw2-fde-dip.c [__OpenBSD__ || __NetBSD__]
	(USE_PT_GNU_EH_FRAME): Do not define if !TARGET_DL_ITERATE_PHDR.

gcc/c-family/ChangeLog:

	PR middle-end/97879
	* c-attribs.c (handle_access_attribute): Handle ATTR_FLAG_INTERNAL.
	Error out on invalid modes.

gcc/c/ChangeLog:
	PR middle-end/97879
	* c-decl.c (start_function): Set ATTR_FLAG_INTERNAL in flags.

gcc/ChangeLog:

	PR middle-end/97879
	* tree-core.h (enum attribute_flags): Add ATTR_FLAG_INTERNAL.

gcc/testsuite/ChangeLog:

	PR middle-end/97879
	* gcc.dg/attr-access-3.c: New test.