GCC 4.2 due to PR33916 miscompiles temp_dump_context ctor, because it doesn't
zero initialize the whole dump_context temporary on which it runs the static
get method and during destruction of the temporary an uninitialized pointer
is deleted.

More recent GCC versions properly zero initialize it and ideally optimize away
the construction/destruction of the temporary, as it isn't used for anything,
but there is no reason to create the temporary, static member functions can
be called without an associated object.

2020-04-15  Gustavo Romero  <gromero@linux.ibm.com>

	PR bootstrap/89494
	* dumpfile.c (selftest::temp_dump_context::temp_dump_context):
	Don't construct a dump_context temporary to call static method.

2020-04-15  Andrea Corallo  <andrea.corallo@arm.com>

	* config/aarch64/falkor-tag-collision-avoidance.c
	(valid_src_p): Check for aarch64_address_info type before
	accessing base field.

This patch fixes an ICE we were seeing due to a missing vec_duplicate pattern.

gcc/ChangeLog:
2020-04-15  Andre Vieira  <andre.simoesdiasvieira@arm.com>

	* config/arm/mve.md (mve_vec_duplicate<mode>): New pattern.
	(V_sz_elem2): Remove unused mode attribute.

gcc/testsuite/ChangeLog:
2020-04-15  Andre Vieira <andre.simoesdiasvieira@arm.com>
            Srinath Parvathaneni <srinath.parvathaneni@arm.com>

	* gcc.target/arm/mve/intrinsics/mve_vec_duplicate.c: New test.

Without disabling this, the pattern can try and move DImode values
between floating point registers and general registers.
The constraints on this pattern can't handle that, and reload goes into
an infinite loop.

This was the cause of a testsuite failure in cde_v_1_mve.c, which is now
gone.

A DImode move for MVE now uses the `movdi_vfp` pattern, which is the same
pattern used for such a move when MVE is not available but the target has
TARGET_HARD_FLOAT.

Testing done:
    Bootstrapped and regtested on arm-none-linux-gnueabihf
    regtested on arm-none-eabi

gcc/ChangeLog:

2020-04-15  Matthew Malcomson  <matthew.malcomson@arm.com>

	* config/arm/arm.md (arm_movdi): Disallow for MVE.

As reported in the PR, GCC 10 (and also 9.3.1 but not 9.3.0) fails to build
when using older binutils which lack LSE support, because those instructions
are used in libgcc.
Thanks to Kyrylo's hint, the following patches (hopefully) allow it to build
even with older binutils by using .inst directive if LSE support isn't
available in the assembler.

2020-04-15  Jakub Jelinek  <jakub@redhat.com>

	PR target/93053
	* configure.ac (LIBGCC_CHECK_AS_LSE): Add HAVE_AS_LSE checking.
	* config/aarch64/lse.S: Include auto-target.h, if HAVE_AS_LSE
	is not defined, use just .arch armv8-a.
	(B, M, N, OPN): Define.
	(COMMENT): New .macro.
	(CAS, CASP, SWP, LDOP): Use .inst directive if HAVE_AS_LSE is not
	defined.  Otherwise, move the operands right after the glue? and
	comment out operands where the macros are used.
	* configure: Regenerated.
	* config.in: Regenerated.

This change started with a bugreport about a typo in one requires testcase
(diagnosed with -Wunknown-pragmas only), but following discussion lead to
noting that we do not diagnose restriction that requires directives in
C/C++ may only appear at file or namespace scope; and several our tests
violated that.

2020-04-15  Jakub Jelinek  <jakub@redhat.com>

	PR c/94593
	* c-parser.c (c_parser_pragma) <case PRAGMA_OMP_REQUIRES>: Reject
	requires directive when not at file scope.

	* parser.c (cp_parser_pragma) <case PRAGMA_OMP_REQUIRES>: Reject
	requires directive when not at file or namespace scope.

	* c-c++-common/gomp/requires-1.c: Fix a typo, requries -> requires.
	Move directives to file scope.
	(i): Remove.
	* c-c++-common/gomp/requires-2.c: Move directives to file scope.
	(i, foo): Remove.
	* c-c++-common/gomp/requires-4.c: Move directives to file scope.
	* c-c++-common/gomp/atomic-19.c: Move requires directive to file scope.
	* c-c++-common/gomp/atomic-20.c: Likewise.
	* c-c++-common/gomp/atomic-21.c: Likewise.
	* c-c++-common/gomp/atomic-22.c: Likewise.
	* gcc.dg/gomp/requires-1.c: New test.
	* g++.dg/gomp/requires-1.C: New test.
	* g++.dg/gomp/requires-2.C: New test.
	* g++.dg/gomp/atomic-18.C: Move requires directive to file scope.

This makes same_type_for_tbaa_p conservative in the same way
get_alias_set is about void * which we allow to alias all other
pointers.

2020-04-15  Richard Biener  <rguenther@suse.de>

	PR middle-end/94539
	* tree-ssa-alias.c (same_type_for_tbaa): Defer to
	alias_sets_conflict_p for pointers.

	* gcc.dg/alias-14.c: Make dg-do run.

Patterns zero_extendhisi2, zero_extendqisi2 and extendhisi2_internal can
load value from memory, but they don't treat volatile memory correctly.
Add %v1 before load instructions to emit 'memw' instruction when
-mserialize-volatile is in effect.

2020-04-14  Max Filippov  <jcmvbkbc@gmail.com>
gcc/
	* config/xtensa/xtensa.md (zero_extendhisi2, zero_extendqisi2)
	(extendhisi2_internal): Add %v1 before the load instructions.

gcc/testsuite/
	* gcc.target/xtensa/pr94584.c: New test.

	* sv.po: Update.

My "simplification" of std::compare_three_way's constraints in commit
f214ffb3 was incorrect, because
std::three_way_comparable_with imposes additional restrictions beyond
the <=> expression being valid.

	* libsupc++/compare (compare_three_way): Fix constraint so that
	BUILTIN-PTR-THREE-WAY does not require three_way_comparable_with.
	* testsuite/18_support/comparisons/object/builtin-ptr-three-way.cc:
	New test.

This also implements the proposed resolution to LWG issue 3247, so that
the ill-formed <=> expression with nullptr is not used.

	PR libstdc++/94562
	* include/bits/shared_ptr.h (operator<=>): Define for C++20.
	* include/bits/shared_ptr_base.h (operator<=>): Likewise.
	* include/bits/unique_ptr.h (operator<=>): Add inline specifier.
	* testsuite/20_util/shared_ptr/comparison/cmp_c++20.cc: New test.
	* testsuite/20_util/shared_ptr/comparison/less.cc: Do not expect
	std::less<A*> to be used when comparing std::shared_ptr<A> objects in
	C++20.

For symmetric transfers to work with C++20 coroutines, it is
currently necessary to tail call the callee coroutine from resume
method of the caller coroutine. The current codegen marks these
resume calls as "MUST_TAIL_CALL" to indicate that the tail call is
required for correctness.

Unfortunately, several targets have ABI constraints that prevent
an indirect tail-call, which results in the PRs compile error.

The change here tests the target sibcall hook for the resume
expression and only marks it as requiring a tail call if that's
supported.

This doesn't fix the underlying problem; that really a solution is
needed to allow the tail-calls (or equivalent) to take place - but
that will be deferred until next stage 1.

gcc/cp/ChangeLog:

2020-04-14  Iain Sandoe  <iain@sandoe.co.uk>

	PR c++/94359
	* coroutines.cc (build_actor_fn): Check that the target can
	support the resume tailcall before mandating it.

gcc/testsuite/ChangeLog:

2020-04-14  Iain Sandoe  <iain@sandoe.co.uk>

	PR c++/94359
	* g++.dg/coroutines/torture/symmetric-transfer-00-basic.C:
	Expect a run fail for targets without arbitrary indirect
	tail-calls.

For rs6000 target, it is not valid to make PC-relative
references to TLS symbols. So addr_to_insn_form() needs
to check if things are TLS before returning PC-rel forms.

2020-04-14  Aaron Sawdey  <acsawdey@linux.ibm.com>

	PR target/94542
	* config/rs6000/rs6000.c (address_to_insn_form): Do not attempt to
	use PC-relative addressing for TLS references.

gcc/testsuite/ChangeLog:

	PR c++/93207
	* g++.dg/concepts/variadic5.C: New test.

This fixes a garbled concepts diagnostic by moving the handling of DECLTYPE_TYPE
from pp_cxx_type_specifier_seq to cxx_pretty_printer::simple_type_specifier, a
move which also seems to be more consistent with the language grammar.

This patch also fixes pretty printing of rvalue reference types via
cxx_pretty_printer::type_id, which eventually calls pp_c_pointer which currently
doesn't distinguish between lvalue and rvalue references.

gcc/c-family/ChangeLog:

	PR c++/85278
	* c-pretty-print.c (pp_c_pointer) <case REFERENCE_TYPE>: Print a double
	ampersand if it's an rvalue reference type.

gcc/cp/ChangeLog:

	PR c++/85278
	* cxx-pretty-print.c (cxx_pretty_printer:simple_type_specifier)
	<case DECLTYPE_TYPE>: Handle DECLTYPE_TYPE here instead of ...
	(pp_cxx_type_specifier_seq) <case DECLTYPE_TYPE>: ... here.
	(cxx_pretty_printer::direct_abstract_declarator) <case DECLTYPE_TYPE>:
	New no-op case.

gcc/testsuite/ChangeLog:

	PR c++/85278
	* g++.dg/concepts/diagnostic9.C: New test.

IPA-SRA can segfault when processing a call to an internal function
because such calls do not have corresponding call graphs and should be
treated like memory accesses anyway, which what the patch below does.

The patch makes an attempt to differentiate between reads and writes,
although for things passed by value it does not make any difference.
It treats all arguments of functions denoted with internal_store_fn_p
as written to, even though in practice only some are, but for IPA-SRA
purposes, actions needed to be taken when processing a read are also
always performed when analyzing a write, so the code is just slightly
pessimistic.  But not as pessimistic as bailing out on any internal
call immediately.

I have LTO bootstrapped and tested the patch on x86_64-linux and
normally bootstrapped and tested it on aarch64-linux, although one
which is not SVE capable.  I would appreciate testing on such machine
too - as well as a small testcase that would follow all relevant
conventions in gcc.target/aarch64/sve.

2020-04-14  Martin Jambor  <mjambor@suse.cz>

	PR ipa/94434
	* ipa-sra.c: Include internal-fn.h.
	(enum isra_scan_context): Update comment.
	(scan_function): Treat calls to internal_functions like loads or stores.

When evaluating the initializer of 'a' in the following example

  struct A {
    A() = default; A(const A&);
    A *p = this;
  };
  constexpr A foo() { return {}; }
  constexpr A a = foo();

the PLACEHOLDER_EXPR for 'this' in the aggregate initializer returned by foo
gets resolved to the RESULT_DECL of foo.  But due to guaranteed RVO, the 'this'
should really be resolved to '&a'.

Fixing this properly by immediately resolving 'this' and PLACEHOLDER_EXPRs to
the ultimate object under construction would in general mean that we would no
longer be able to cache constexpr calls for which RVO possibly applies, because
the result of the call may now depend on the ultimate object under construction.

So as a mostly correct stopgap solution that retains cachability of RVO'd
constexpr calls, this patch fixes this issue by rewriting all occurrences of the
RESULT_DECL in the result of a constexpr function call with the current object
under construction, after the call returns.  This means the 'this' pointer
during construction of the temporary will still point to the temporary object
instead of the ultimate object, but besides that this approach seems
functionally equivalent to the proper approach.

gcc/cp/ChangeLog:

	PR c++/94034
	* constexpr.c (replace_result_decl_data): New struct.
	(replace_result_decl_data_r): New function.
	(replace_result_decl): New function.
	(cxx_eval_call_expression): Use it.
	* tree.c (build_aggr_init_expr): Set the location of the AGGR_INIT_EXPR
	to that of its initializer.

gcc/testsuite/ChangeLog:

	PR c++/94034
	* g++.dg/cpp0x/constexpr-empty15.C: New test.
	* g++.dg/cpp1y/constexpr-nsdmi6a.C: New test.
	* g++.dg/cpp1y/constexpr-nsdmi6b.C: New test.
	* g++.dg/cpp1y/constexpr-nsdmi7a.C: New test.
	* g++.dg/cpp1y/constexpr-nsdmi7b.C: New test.

2020-04-14  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/94573
	* gcc.dg/store_merging_30.c: New test.

In this PR the testcase ICEs because a BIT_INSERT_EXPR whose replaced bits are
not fully inside the container is generated. A size check is added to avoid
this kind of ICE.

gcc/ChangeLog:

	PR tree-optimization/94574
	* tree-ssa.c (non_rewritable_lvalue_p): Add size check when analyzing
	whether a vector-insert is rewritable using a BIT_INSERT_EXPR.

gcc/testsuite/ChangeLog:

	PR tree-optimization/94574
	* gcc.dg/pr94574.c: New test.

Even though ix86_hard_regno_mode_ok doesn't allow xmm16-xmm31 nor
ymm16-ymm31 in 128/256 bit modes when AVX512VL is disabled, LRA can
still generate reg to reg moves with xmm16-xmm31 and ymm16-ymm31 in
128/256 bit modes.  Remove mode size check in ix86_get_ssemov.

gcc/

	PR target/94561
	* config/i386/i386.c (ix86_get_ssemov): Remove mode size check.

gcc/testsuite/

	PR target/94561
	* gcc.target/i386/pr94561.c: New test.

2020-04-14  Martin Jambor  <mjambor@suse.cz>

	* MAINTAINERS (Reviewers): Add myself as callgraph (IPA) reviewer.

	* module.c (gfc_match_use): Fix name-conflict check for use-associating
	the same symbol again in a submodule.

	* gfortran.dg/use_rename_10.f90: New.
	* gfortran.dg/use_rename_11.f90: New.

2020-04-14  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/94270
	* interface.c (gfc_get_formal_from_actual_arglist): Always
	set artificial attribute for symbols.
	* trans-decl.c (generate_local_decl): Do not warn if the
	symbol is artifical.

2020-04-14  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/94270
	* gfortran.dg/warn_unused_dummy_argument_6.f90: New test.

ChangeLog:

2020-04-14  Martin Liska  <mliska@suse.cz>

	* MAINTAINERS: Add me as callgraph (IPA) reviewer.

	PR libstdc++/94565
	* libsupc++/compare (__unspec): Add noexcept-specifier to constructor.
	* testsuite/18_support/comparisons/categories/94565.cc: New test.

While reviewing [basic.scope.param] I noticed we don't show the location
of the previous declaration when giving an error about "A parameter name
shall not be redeclared in the outermost block of the function definition".

	PR c++/94588
	* name-lookup.c (check_local_shadow): Add an inform call.

	* g++.dg/diagnostic/redeclaration-1.C: Add dg-message.

gcc/ChangeLog:
	* doc/extend.texi (-Wall): Mention -Wformat-overflow and
	-Wformat-truncation.  Move -Wzero-length-bounds last.
	(-Wrestrict): Document positive form of option enabled by -Wall.

gcc/c-family/ChangeLog:

	PR c/92326
	* c-pretty-print.c (c_pretty_printer::direct_abstract_declarator): Avoid
	printing array bound for flexible array members.

gcc/testsuite/ChangeLog:

	PR c/92326
	* c-c++-common/Warray-bounds-8.c: New test.
	* gcc.dg/Warray-bounds-46.c: Adjust expected format of flexible array
	memebrs in diagnostics.
	* gcc.dg/Warray-bounds-49.c: Same.

We are hitting a recursive loop when printing the signature of a function
containing a decltype([]{}) type.  The loop is

  dump_function_decl -> dump_substitution
		     -> dump_template_bindings
		     -> dump_type
		     -> dump_aggr_type
		     -> dump_scope -> dump_function_decl

and we loop because dump_template_bindings wants to print the resolved type of
decltype([]{}) (i.e. just a lambda type), so it calls dump_aggr_type, which
wants to print the function scope of the lambda type.  But the function scope of
the lambda type is the function which we're in the middle of printing.

This patch breaks the loop by passing TFF_NO_FUNCTION_ARGUMENTS to
dump_function_decl from dump_scope, so that we avoid recursing into
dump_substitution and ultimately looping.

This also means we no longer emit the "[with ...]" clause when printing a
function template scope, and we instead just emit its template argument list in
a more natural way, e.g. instead of
    foo(int, char) [with T=bool]::x
we would now print
    foo<bool>::x
which seems like an improvement on its own.

The full signature of the function 'spam' in the below testcase is now
  void spam(decltype (<lambda>)*) [with T = int; decltype (<lambda>) = spam<int>::<lambda()>]

gcc/cp/ChangeLog:

	PR c++/94521
	* error.c (dump_scope): Pass TFF_NO_FUNCTION_ARGUMENTS to
	dump_function_decl when printing a function template instantiation as a
	scope.

gcc/testsuite/ChangeLog:

	PR c++/94521
	* g++.dg/cpp2a/lambda-uneval12.C: New test.

In this PR we're incorrectly rejecting a self-modifying constexpr initializer as
a consequence of the fix for PR78572.

It looks like however that the fix for PR78572 is obsoleted by the fix for
PR89336: the testcase from the former PR successfully compiles even with its fix
reverted.

But then further testing showed that the analogous testcase of PR78572 where the
array has an aggregate element type is still problematic (i.e. we ICE) even with
the fix for PR78572 applied.  The reason is that in cxx_eval_bare_aggregate we
attach a constructor_elt of aggregate type always to the end of the new
CONSTRUCTOR, but that's not necessarily correct if the CONSTRUCTOR is
self-modifying.  We should instead be using get_or_insert_ctor_field to insert
the constructor_elt in the right place.

So this patch reverts the PR78572 fix and makes the appropriate changes to
cxx_eval_bare_aggregate.  This fixes PR94470, and we now are also able to fully
reduce the initializers of 'arr' and 'arr2' in the new test array57.C to
constant initializers.

gcc/cp/ChangeLog:

	PR c++/94470
	* constexpr.c (get_or_insert_ctor_field): Set default value of parameter
	'pos_hint' to -1.
	(cxx_eval_bare_aggregate): Use get_or_insert_ctor_field instead of
	assuming the the next index belongs at the end of the new CONSTRUCTOR.
	(cxx_eval_store_expression): Revert PR c++/78572 fix.

gcc/testsuite/ChangeLog:

	PR c++/94470
	* g++.dg/cpp1y/constexpr-nsdmi8.C: New test.
	* g++.dg/cpp1y/constexpr-nsdmi9.C: New test.
	* g++.dg/init/array57.C: New test.

The current standard draft (n4861) amends the cpp builtin for
coroutines to '__cpp_impl_coroutine', no other change.

gcc/c-family/ChangeLog:

2020-04-13  Iain Sandoe  <iain@sandoe.co.uk>

	* c-cppbuiltin.c (c_cpp_builtins): Update coroutines builtin
	define, per n4861.

gcc/testsuite/ChangeLog:

2020-04-13  Iain Sandoe  <iain@sandoe.co.uk>

	* g++.dg/coroutines/coro-pre-proc.C: Update coroutines builtin
	define, per n4861.
	* g++.dg/coroutines/coro.h: Likewise.

libstdc++-v3/ChangeLog:

2020-04-13  Iain Sandoe  <iain@sandoe.co.uk>

	* include/std/coroutine: Update coroutines builtin define,
	per n4861.

	* doc/extend.texi: Add realloc to list of built-in functions
	are recognized by the compiler.

From XCode 11.4 on 10.14/15 use of 10.6 and 10.7 is deprecated.
The tools issue diagnostics if -mmacosx-version-min= < 10.8

Adjust the testcase to avoid that usage on 10.14, 10.15 for now.

gcc/testsuite/ChangeLog:

2020-04-13  Iain Sandoe  <iain@sandoe.co.uk>

	* gcc.dg/darwin-version-1.c: Use -mmacosx-version-min= 10.8
	for system versions 10.14 and 10.15.

2020-04-13  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/87644
	* gfortran.dg/variable_parameter.f90: New test.

The idea is not have another resolution of a pointer if an error has
occurred previously.

2020-04-13  Linus Koenig <link@sig-st.de>

	PR fortran/94192
	* resolve.c (resolve_fl_var_and_proc): Set flag "error" to 1 if
	pointer is found to not have an assumed rank or a deferred shape.
	* simplify.c (simplify_bound): If an error has been issued for a
	given pointer, one should not attempt to find its bounds.

2020-04-13  Linus Koenig <link@sig-st.de>

	PR fortran/94192
	* gfortran.dg/bound_resolve_after_error_1.f90: New test.

My fix for 94147 was confusing no-linkage with internal linkage, at
the language level.  That's wrong. (the std is confusing here, because
it describes linkage of names (which is wrong), and lambdas have no
names)

Lambdas with extra-scope, have linkage.  However, at the
implementation-level that linkage is at least as restricted as the
linkage of the extra-scope decl.

Further, when instantiating a variable initialized by a lambda, we
must determine the visibility of the variable itself, before
instantiating its initializer.  If the template arguments are internal
(or no-linkage), the variable will have internal linkage, regardless
of the linkage of the template it is instantiated from.  We need to
know that before instantiating the lambda, so we can restrict its
linkage correctly.

	* decl2.c (determine_visibility): A lambda's visibility is
	affected by its extra scope.
	* pt.c (instantiate_decl): Determine var's visibility before
	instantiating its initializer.
	* tree.c (no_linkage_check): Revert code looking at visibility of
	lambda's extra scope.
`	gcc/cp/
	* g++.dg/cpp0x/lambda/pr94426-[12].C: New.
	* g++.dg/abi/lambda-vis.C: Drop a warning.
	* g++.dg/cpp0x/lambda/lambda-mangle.C: Lambda visibility on
	variable changes.
	* g++.dg/opt/dump1.C: Drop warnings of no import.

We must restore the frame pointer in word_mode for eh_return epilogues
since the upper 32 bits of RBP register can have any values.

Tested on Linux/x32 and Linux/x86-64.

	PR target/94556
	* config/i386/i386.c (ix86_expand_epilogue): Restore the frame
	pointer in word_mode for eh_return epilogues.