* g++.dg/warn/Wstringop-overflow-4.C: Adjust test to avoid failures
	due to an aparrent VRP limtation.
	* gcc.dg/Wstringop-overflow-25.c: Same.

2020-01-20  Fangrui Song  <maskray@google.com>

gcc/
	PR middle-end/93194
	* targhooks.c (default_print_patchable_function_entry): Align to
	POINTER_SIZE.

__has_include is funky in that it is macro-like from the POV of #ifdef and
friends, but lexes its parenthesize argument #include-like.  We were
failing the second part of that, because we used a forwarding macro to an
internal name, and hence always lexed the argument in macro-parameter
context.  We componded that by not setting the right flag when lexing, so
it didn't even know.  Mostly users got lucky.

This reimplements the handline.
1) Remove the forwarding, but declare object-like macros that
expand to themselves.  This satisfies the #ifdef requirement

2) Correctly set angled_brackets when lexing the parameter.  This tells
the lexer (a) <...> is a header name and (b) "..." is too (not a string).

3) Remove the in__has_include lexer state, just tell find_file that that's
what's happenning, so it doesn't emit an error.

We lose the (undocumented) ability to #undef __has_include.  That may well
have been an accident of implementation.  There are no tests for it.

We gain __has_include behaviour for all users of the preprocessors -- not
just the C-family ones that defined a forwarding macro.

	libcpp/
	PR preprocessor/80005
	* include/cpplib.h (BT_HAS_ATTRIBUTE): Fix comment.
	* internal.h (struct lexer_state): Delete in__has_include field.
	(struct spec_nodes): Rename n__has_include{,_next}__ fields.
	(_cpp_defined_macro_p): New.
	(_cpp_find_file): Add has_include parm.
	* directives.c (lex_macro_node): Combine defined,
	__has_inline{,_next} checking.
	(do_ifdef, do_ifndef): Use _cpp_defined_macro_p.
	(_cpp_init_directives): Refactor.
	* expr.c (parse_defined): Use _cpp_defined_macro_p.
	(eval_token): Adjust parse_has_include calls.
	(parse_has_include): Add OP parameter.  Reimplement.
	* files.c (_cpp_find_file): Add HAS_INCLUDE parm.  Use it to
	inhibit error message.
	(_cpp_stack_include): Adjust _cpp_find_file call.
	(_cpp_fake_include, _cpp_compare_file_date): Likewise.
	(open_file_failed): Remove in__has_include check.
	(_cpp_has_header): Adjust _cpp_find_file call.
	* identifiers.c (_cpp_init_hashtable): Don't init
	__has_include{,_next} here ...
	* init.c (cpp_init_builtins): ... init them here.  Define as
	macros.
	(cpp_read_main_file): Adjust _cpp_find_file call.
	* pch.c (cpp_read_state): Adjust __has_include{,_next} access.
	* traditional.c (_cpp_scan_out_locgical_line): Likewise.

	gcc/c-family/
	PR preprocessor/80005
	* c-cppbuiltins.c (c_cpp_builtins): Don't define __has_include{,_next}.

	gcc/testsuite/
	PR preprocessor/80005
	* g++.dg/cpp1y/feat-cxx14.C: Adjust.
	* g++.dg/cpp1z/feat-cxx17.C: Adjust.
	* g++.dg/cpp2a/feat-cxx2a.C: Adjust.
	* g++.dg/cpp/pr80005.C: New.

Should've have checked for the existance of a non static integer
using scan-tree-dump instead of scan-tree-dump-not. A cut and paste
error.

To add x32 support to -mtls-dialect=gnu2, we need to replace DI with
P in GNU2 TLS patterns.  Since DEST set by tls_dynamic_gnu2_64 is in
ptr_mode, PLUS in GNU2 TLS address computation must be done in ptr_mode
to support -maddress-mode=long.  Also replace the "{q}" suffix on lea
with "%z0" to support both 32-bit and 64-bit destination register.

Tested on Linux/x86-64.

gcc/

	PR target/93319
	* config/i386/i386.c (legitimize_tls_address): Pass Pmode to
	gen_tls_dynamic_gnu2_64.  Compute GNU2 TLS address in ptr_mode.
	* config/i386/i386.md (tls_dynamic_gnu2_64): Renamed to ...
	(@tls_dynamic_gnu2_64_<mode>): This.  Replace DI with P.
	(*tls_dynamic_gnu2_lea_64): Renamed to ...
	(*tls_dynamic_gnu2_lea_64_<mode>): This.  Replace DI with P.
	Remove the {q} suffix from lea.
	(*tls_dynamic_gnu2_call_64): Renamed to ...
	(*tls_dynamic_gnu2_call_64_<mode>): This.  Replace DI with P.
	(*tls_dynamic_gnu2_combine_64): Renamed to ...
	(*tls_dynamic_gnu2_combine_64_<mode>): This.  Replace DI with P.
	Pass Pmode to gen_tls_dynamic_gnu2_64.

gcc/testsuite/

	PR target/93319
	* gcc.target/i386/pr93319-1a.c: New test.
	* gcc.target/i386/pr93319-1b.c: Likewise.
	* gcc.target/i386/pr93319-1c.c: Likewise.
	* gcc.target/i386/pr93319-1d.c: Likewise.

Contrary to all documentation, SLOW_BYTE_ACCESS simply means accessing
bitfields by their declared type, which results in better codegeneration.

gcc/
	* config/aarch64/aarch64.h (SLOW_BYTE_ACCESS): Set to 1.

2020-01-20  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* config/aarch64/aarch64-sve-builtins-base.cc
	(svld1ro_impl::memory_vector_mode): Remove parameter name.

We were pruning type-local subroutine DIEs if their context is unused
despite us later needing those DIEs as abstract origins for inlines.
The patch makes code already present for -fvar-tracking-assignments
unconditional.

2020-01-20  Richard Biener  <rguenther@suse.de>

	PR debug/92763
	* dwarf2out.c (prune_unused_types): Unconditionally mark
	called function DIEs.

	* g++.dg/debug/pr92763.C: New testcase.

The initial structure for vendor and personal branches makes use of
the default remote (normally origin) for the upstream
repository).  Unfortunately, this causes some confusion, especially for
personal branches because a push will not push to the correct upstream
location.  This can be 'fixed' by adding a push refspec for the remote,
but that has the unfortunate consequence of breaking the push.default
behaviour for git push, and it becomes too easy to accidentally commit
something unintended to the main parts of the repository.

To work around this, this patch changes the configuration to use
separate 'remotes' for these additional refs, with one remote for the
personal space and another remote for each vendor's space.  The
personal space is called after the user's preferred branch-space
prefix (default 'me'), the vendor spaces are called
vendors/<vendor-name>.

As far as possible, I've made the script automatically restructure any
existing fetch or push lines that earlier versions of the scripts may
have created - the gcc-git-customization.sh script will convert all
vendor refs that it can find, so it is not necessary to re-add any
vendors you've already added.

You might, however, want to run
  git remote prune <origin>
after running to clean up any stale upstream-refs that might still be
in your local repo, and then
  git fetch vendors/<vendor>
or
  git fetch <me>
to re-populate the remotes/ structures.

Also, for any branch you already have that tracks a personal or vendor
branch upstream, you might need to run
  git config branch.<name>.remote <new-remote>

so that merges and pushes go to the right place (I haven't attempted
to automate this last part).

For vendors, the new structure means that

  git checkout -b <vendor>/<branch> remotes/vendors/<vendor>/<branch>

will correctly set up a remote tracking branch.

Please be aware that if you have multiple personal branches set up, then

  git push <me>

will still consider all of them for pushing.  If you only want to push
one branch, then either write
  git push <me> HEAD
or
  git push <me> <me>/branch
as appropriate.

And don't forget '-n' (--dry-run) to see what would be done if this
were not a dry run.

Finally, now that the vendors spaces are isolated from each other and
from the other spaces, I've added an option "--enable-push" to
git-fetch-vendor.sh.  If passed, then a "push" spec will be added for
that vendor to enable pushing to the upstream.  If you re-run the
script for the same vendor without the option, the push spec will be
removed.

	* gcc-git-customization.sh: Check that user-supplied remote
	name exists before continuting.  Use a separate remotes for the
	personal commit area.  Convert existing personal and vendor
	fetch rules to new layout.
	* git-fetch-vendor.sh: New vendor layout.  Add --enable-push
	option.

	PR c++/92536
	* g++.dg/cpp1z/pr92536.C: New.

	PR tree-optimization/93199
	* tree-eh.c (struct leh_state): Add
	new field outer_non_cleanup.
	(cleanup_is_dead_in): Pass leh_state instead
	of eh_region.  Add a checking that state->outer_non_cleanup
	points to outer non-clean up region.
	(lower_try_finally): Record outer_non_cleanup
	for this_state.
	(lower_catch): Likewise.
	(lower_eh_filter): Likewise.
	(lower_eh_must_not_throw): Likewise.
	(lower_cleanup): Likewise.

When versioning is run the IL is already mangled and finding
a VECTORIZED_CALL IFN can fail.

2020-01-20  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/93094
	* tree-vectorizer.h (vect_loop_versioning): Adjust.
	(vect_transform_loop): Likewise.
	* tree-vectorizer.c (try_vectorize_loop_1): Pass down
	loop_vectorized_call to vect_transform_loop.
	* tree-vect-loop.c (vect_transform_loop): Pass down
	loop_vectorized_call to vect_loop_versioning.
	* tree-vect-loop-manip.c (vect_loop_versioning): Use
	the earlier discovered loop_vectorized_call.

	* gcc.dg/vect/pr93094.c: New testcase.

Clean up references to SVN in in the GCC docs, redirecting to Git
documentation as appropriate.

Where references to "the source code repository" rather than a
specific VCS make sense, I have used them. You might, after
all, change VCSes again someday.

I have not modified either generated HTML files nor maintainer scripts.
These changes should be complete with repect to the documentation tree.

2020-01-19  Eric S. Raymond <esr@thyrsus.com>

	gcc/
	* doc/contribute.texi: Update for SVN -> Git transition.
	* doc/install.texi: Likewise.

	libstdc++-v3
	* doc/xml/faq.xml: Update for SVN -> Git transition.
	* doc/xml/manual/appendix_contributing.xml: Likewise.
	* doc/xml/manual/status_cxx1998.xml: Likewise.
	* doc/xml/manual/status_cxx2011.xml: Likewise.
	* doc/xml/manual/status_cxx2014.xml: Likewise.
	* doc/xml/manual/status_cxx2017.xml: Likewise.
	* doc/xml/manual/status_cxx2020.xml: Likewise.
	* doc/xml/manual/status_cxxtr1.xml: Likewise.
	* doc/xml/manual/status_cxxtr24733.xml: Likewise.

gcc/testsuite/ChangeLog:
	* gcc.dg/analyzer/CVE-2005-1689-dedupe-issue.c: Ensure that all
	test names are unique.
	* gcc.dg/analyzer/attribute-nonnull.c: Likewise.
	* gcc.dg/analyzer/conditionals-notrans.c: Likewise.
	* gcc.dg/analyzer/data-model-1.c: Likewise.
	* gcc.dg/analyzer/data-model-18.c: Likewise.
	* gcc.dg/analyzer/data-model-8.c: Likewise.
	* gcc.dg/analyzer/data-model-9.c: Likewise.
	* gcc.dg/analyzer/file-1.c: Likewise.
	* gcc.dg/analyzer/file-paths-1.c: Likewise.
	* gcc.dg/analyzer/loop-2.c: Likewise.
	* gcc.dg/analyzer/loop-2a.c: Likewise.
	* gcc.dg/analyzer/loop-4.c: Likewise.
	* gcc.dg/analyzer/loop.c: Likewise.
	* gcc.dg/analyzer/malloc-1.c: Likewise.
	* gcc.dg/analyzer/malloc-2.c: Likewise.
	* gcc.dg/analyzer/malloc-ipa-10.c: Likewise.
	* gcc.dg/analyzer/malloc-ipa-2.c: Likewise.
	* gcc.dg/analyzer/malloc-macro-separate-events.c: Likewise.
	* gcc.dg/analyzer/malloc-paths-1.c: Likewise.
	* gcc.dg/analyzer/malloc-paths-2.c: Likewise.
	* gcc.dg/analyzer/malloc-paths-3.c: Likewise.
	* gcc.dg/analyzer/malloc-paths-4.c: Likewise.
	* gcc.dg/analyzer/malloc-paths-5.c: Likewise.
	* gcc.dg/analyzer/malloc-paths-7.c: Likewise.
	* gcc.dg/analyzer/malloc-paths-9.c: Likewise.
	* gcc.dg/analyzer/operations.c: Likewise.
	* gcc.dg/analyzer/params.c: Likewise.
	* gcc.dg/analyzer/pattern-test-1.c: Likewise.
	* gcc.dg/analyzer/pattern-test-2.c: Likewise.
	* gcc.dg/analyzer/sensitive-1.c: Likewise.
	* gcc.dg/analyzer/switch.c: Likewise.
	* gcc.dg/analyzer/taint-1.c: Likewise.
	* gcc.dg/analyzer/unknown-fns.c: Likewise.

	* lib/target-supports.exp (effective_target_march_option): New.

I see no (other) way to, depending on the absence of an option,
add an option for a specific target.

For gcc.dg/torture/pr26515.c and cris-elf, you get an error for
supplying multiple (different) -march=... options (where that
error is desirable), like testing cris-elf with
RUNTESTFLAGS=--target_board=cris-sim/arch=v8, where otherwise
-march=v10 and -march=v8 will both be given, and the test would
fail.

For historians, this was accidentally misordered and committed after
the (first) patch using march_option.  Oops.

	* gcc.dg/torture/pr26515.c (cris*-*-*): Conditionalize
	-march=v10 option on target ! march_option.
	* gcc.target/cris/asm-v10.S, gcc.target/cris/inasm-v10.c,
	gcc.target/cris/sync-1-v10.c: Similar.

This patch differs from the reverted patch for 33799 in that it adds the
CLEANUP_STMT for the return value at the end of the function, and only if
we've seen a cleanup that might throw, so it should not affect most C++11
code.

	* cp-tree.h (current_retval_sentinel): New macro.
	(struct language_function): Add throwing_cleanup bitfield.
	* decl.c (cxx_maybe_build_cleanup): Set it.
	* except.c (maybe_set_retval_sentinel)
	(maybe_splice_retval_cleanup): New functions.
	* parser.c (cp_parser_compound_statement): Call
	maybe_splice_retval_cleanup.
	* typeck.c (check_return_expr): Call maybe_set_retval_sentinel.

Since we removed the special parsing for C++11 lambdas, it's just been an
open-coded copy of cp_parser_function_body.  So let's call it instead.  This
avoids the need to change this code in my revised 33799 patch.

	* parser.c (cp_parser_lambda_body): Use cp_parser_function_body.

this patch implements verifier and fixes one bug where speculative calls
produced by ipa-devirt ended up having num_speculative_call_targets = 0
instead of 1.

	* cgraph.c (cgraph_edge::make_speculative): Increase number of
	speculative targets.
	(verify_speculative_call): New function
	(cgraph_node::verify_node): Use it.
	* ipa-profile.c (ipa_profile): Fix formating; do not set number of
	speculations.

this fixes two issues with the new multi-target speculation code which reproduce
on Firefox.  I can now build firefox with FDO locally but on Mozilla build bots
it still fails with ICE in speculative_call_info.

One problem is that speuclative code compares call_stmt and lto_stmt_uid in
a way that may get unwanted effect when these gets out of sync.  It does not
make sense to have both non-zero so I added code clearing it and sanity check
that it is kept this way.

Other problem is cgraph_edge::make_direct not working well with multiple
targets.  In this case it removed one speuclative target and the indirect call
leaving other targets in the tree.

This is fixed by iterating across all targets and removing all except the good
one (if it exists).

	PR lto/93318
	* cgraph.c (cgraph_edge::resolve_speculation): Fix foramting.
	(cgraph_edge::make_direct): Remove all indirect targets.
	(cgraph_edge::redirect_call_stmt_to_callee): Use make_direct..
	(cgraph_node::verify_node): Verify that only one call_stmt or
	lto_stmt_uid is set.
	* cgraphclones.c (cgraph_edge::clone): Set only one call_stmt or
	lto_stmt_uid.
	* lto-cgraph.c (lto_output_edge): Simplify streaming of stmt.
	(lto_output_ref): Simplify streaming of stmt.
	* lto-streamer-in.c (fixup_call_stmt_edges_1): Clear lto_stmt_uid.

When building offloading cross-compiler from x86_64-linux to nvptx-none, the
build fails with:
../../gcc/cp/coroutines.cc: In function 'tree_node* get_fn_local_identifier(tree, const char*)':
../../gcc/cp/coroutines.cc:2255:12: error: expected ';' before 'char'
 2255 |   sep = "$"
      |            ^
      |            ;
......
 2262 |   char *an;
      |   ~~~~

2020-01-18  Jakub Jelinek  <jakub@redhat.com>

	* coroutines.cc (get_fn_local_identifier): Fix NO_DOT_IN_LABEL
	but non-NO_DOLLAR_IN_LABEL case build.

	* config/cris/arit.c (DS): Apply attribute fallthrough.

Without this, there are, for each compilation of arit.c, 30ish
occurrences of "this statement may fall through
[-Wimplicit-fallthrough=]", for lines that look like
    case 32: DS; case 31: DS; case 30: DS; case 29: DS;

	PR libgcc/92988
	* crtstuff.c (__do_global_dtors_aux): Only call __cxa_finalize if
	DEFAULT_USE_CXA_ATEXIT is true.

This marks the parameter &fi as unused so it doesn't
cause a boostrap failure.

committed under the obvious rule.

gcc/ChangeLog:

	* config/aarch64/aarch64-sve-builtins-base.cc (memory_vector_mode):
	Mark parameter unused.

2020-01-18  Jakub Jelinek  <jakub@redhat.com>

	PR c/92833
	* c-c++-common/pr92833-4.c: Fix dg-message syntax.

I'm sorry to say that there's no incentive to maintain
crisv32-*-* and cris-*-linux* configurations beyond nostalgia,
(and I'm out of that for the moment).  Support in the Linux
kernel for either applicable CRIS variant (CRIS v10 and CRIS
v32) is gone since 2018.  Their related part of the cc0
transition workload would be noticable.  Note that cris-elf
remains, but crisv32-elf and the CRIS v32 multilib will be
removed, at least for now.

I'm not completely happy about the message (the next-next line
after the context) "*** unless a maintainer comes forward"
because it'd have to be at an infinitesimal maintenance cost to
the cris-elf support.  Still, I'm not bothered enough to add
another case construct or means for "planned obsolescence".

	* varpool.c (ctor_useable_for_folding_p): Fix grammar.

C++20 coroutines introduces a new operator with a mangling of 'aw'.
This patch adds that to libiberty's demangler.

libiberty/ChangeLog:

2020-01-18  Iain Sandoe  <iain@sandoe.co.uk>

	* cp-demangle.c (cplus_demangle_operators): Add the co_await
	operator.
	* testsuite/demangle-expected: Test co_await operator mangling.

This is the squashed version of the first 6 patches that were split to
facilitate review.

The changes to libiberty (7th patch) to support demangling the co_await
operator stand alone and are applied separately.

The patch series is an initial implementation of a coroutine feature,
expected to be standardised in C++20.

Standardisation status (and potential impact on this implementation)
--------------------------------------------------------------------

The facility was accepted into the working draft for C++20 by WG21 in
February 2019.  During following WG21 meetings, design and national body
comments have been reviewed, with no significant change resulting.

The current GCC implementation is against n4835 [1].

At this stage, the remaining potential for change comes from:

* Areas of national body comments that were not resolved in the version we
  have worked to:
  (a) handling of the situation where aligned allocation is available.
  (b) handling of the situation where a user wants coroutines, but does not
      want exceptions (e.g. a GPU).

* Agreed changes that have not yet been worded in a draft standard that we
  have worked to.

It is not expected that the resolution to these can produce any major
change at this phase of the standardisation process.  Such changes should be
limited to the coroutine-specific code.

ABI
---

The various compiler developers 'vendors' have discussed a minimal ABI to
allow one implementation to call coroutines compiled by another.

This amounts to:

1. The layout of a public portion of the coroutine frame.

 Coroutines need to preserve state across suspension points, the storage for
 this is called a "coroutine frame".

 The ABI mandates that pointers into the coroutine frame point to an area
 begining with two function pointers (to the resume and destroy functions
 described below); these are immediately followed by the "promise object"
 described in the standard.

 This is sufficient that the builtins can take a coroutine frame pointer and
 determine the address of the promise (or call the resume/destroy functions).

2. A number of compiler builtins that the standard library might use.

  These are implemented by this patch series.

3. This introduces a new operator 'co_await' the mangling for which is also
agreed between vendors (and has an issue filed for that against the upstream
c++abi).  Demangling for this is added to libiberty in a separate patch.

The ABI has currently no target-specific content (a given psABI might elect
to mandate alignment, but the common ABI does not do this).

Standard Library impact
-----------------------

The current implementations require addition of only a single header to
the standard library (no change to the runtime).  This header is part of
the patch.

GCC Implementation outline
--------------------------

The standard's design for coroutines does not decorate the definition of
a coroutine in any way, so that a function is only known to be a coroutine
when one of the keywords (co_await, co_yield, co_return) is encountered.

This means that we cannot special-case such functions from the outset, but
must process them differently when they are finalised - which we do from
"finish_function ()".

At a high level, this design of coroutine produces four pieces from the
original user's function:

  1. A coroutine state frame (taking the logical place of the activation
     record for a regular function).  One item stored in that state is the
     index of the current suspend point.
  2. A "ramp" function
     This is what the user calls to construct the coroutine frame and start
     the coroutine execution.  This will return some object representing the
     coroutine's eventual return value (or means to continue it when it it
     suspended).
  3. A "resume" function.
     This is what gets called when a the coroutine is resumed when suspended.
  4. A "destroy" function.
     This is what gets called when the coroutine state should be destroyed
     and its memory released.

The standard's coroutines involve cooperation of the user's authored function
with a provided "promise" class, which includes mandatory methods for
handling the state transitions and providing output values.  Most realistic
coroutines will also have one or more 'awaiter' classes that implement the
user's actions for each suspend point.  As we parse (or during template
expansion) the types of the promise and awaiter classes become known, and can
then be verified against the signatures expected by the standard.

Once the function is parsed (and templates expanded) we are able to make the
transformation into the four pieces noted above.

The implementation here takes the approach of a series of AST transforms.
The state machine suspend points are encoded in three internal functions
(one of which represents an exit from scope without cleanups).  These three
IFNs are lowered early in the middle end, such that the majority of GCC's
optimisers can be run on the resulting output.

As a design choice, we have carried out the outlining of the user's function
in the front end, and taken advantage of the existing middle end's abilities
to inline and DCE where that is profitable.

Since the state machine is actually common to both resumer and destroyer
functions, we make only a single function "actor" that contains both the
resume and destroy paths.  The destroy function is represented by a small
stub that sets a value to signal the use of the destroy path and calls the
actor.  The idea is that optimisation of the state machine need only be done
once - and then the resume and destroy paths can be identified allowing the
middle end's inline and DCE machinery to optimise as profitable as noted
above.

The middle end components for this implementation are:

A pass that:
 1. Lowers the coroutine builtins that allow the standard library header to
    interact with the coroutine frame (these fairly simple logical or
    numerical substitution of values, given a coroutine frame pointer).
 2. Lowers the IFN that represents the exit from state without cleanup.
    Essentially, this becomes a gimple goto.
 3. Sets the final size of the coroutine frame at this stage.

A second pass (that requires the revised CFG that results from the lowering
of the scope exit IFNs in the first).

 1. Lower the IFNs that represent the state machine paths for the resume and
    destroy cases.

Patches squashed into this commit:

[C++ coroutines 1] Common code and base definitions.

This part of the patch series provides the gating flag, the keywords,
cpp defines etc.

[C++ coroutines 2] Define builtins and internal functions.

This part of the patch series provides the builtin functions
used by the standard library code and the internal functions
used to implement lowering of the coroutine state machine.

[C++ coroutines 3] Front end parsing and transforms.

There are two parts to this.

1. Parsing, template instantiation and diagnostics for the standard-
   mandated class entries.

  The user authors a function that becomes a coroutine (lazily) by
  making use of any of the co_await, co_yield or co_return keywords.

  Unlike a regular function, where the activation record is placed on the
  stack, and is destroyed on function exit, a coroutine has some state that
  persists between calls - the 'coroutine frame' (thus analogous to a stack
  frame).

  We transform the user's function into three pieces:
  1. A so-called ramp function, that establishes the coroutine frame and
     begins execution of the coroutine.
  2. An actor function that contains the state machine corresponding to the
     user's suspend/resume structure.
  3. A stub function that calls the actor function in 'destroy' mode.

  The actor function is executed:
   * from "resume point 0" by the ramp.
   * from resume point N ( > 0 ) for handle.resume() calls.
   * from the destroy stub for destroy point N for handle.destroy() calls.

  The C++ coroutine design described in the standard makes use of some helper
  methods that are authored in a so-called "promise" class provided by the
  user.

  At parse time (or post substitution) the type of the coroutine promise
  will be determined.  At that point, we can look up the required promise
  class methods and issue diagnostics if they are missing or incorrect.  To
  avoid repeating these actions at code-gen time, we make use of temporary
  'proxy' variables for the coroutine handle and the promise - which will
  eventually be instantiated in the coroutine frame.

  Each of the keywords will expand to a code sequence (although co_yield is
  just syntactic sugar for a co_await).

  We defer the analysis and transformatin until template expansion is
  complete so that we have complete types at that time.

2. AST analysis and transformation which performs the code-gen for the
   outlined state machine.

   The entry point here is morph_fn_to_coro () which is called from
   finish_function () when we have completed any template expansion.

   This is preceded by helper functions that implement the phases below.

   The process proceeds in four phases.

   A Initial framing.
     The user's function body is wrapped in the initial and final suspend
     points and we begin building the coroutine frame.
     We build empty decls for the actor and destroyer functions at this
     time too.
     When exceptions are enabled, the user's function body will also be
     wrapped in a try-catch block with the catch invoking the promise
     class 'unhandled_exception' method.

   B Analysis.
     The user's function body is analysed to determine the suspend points,
     if any, and to capture local variables that might persist across such
     suspensions.  In most cases, it is not necessary to capture compiler
     temporaries, since the tree-lowering nests the suspensions correctly.
     However, in the case of a captured reference, there is a lifetime
     extension to the end of the full expression - which can mean across a
     suspend point in which case it must be promoted to a frame variable.

     At the conclusion of analysis, we have a conservative frame layout and
     maps of the local variables to their frame entry points.

   C Build the ramp function.
     Carry out the allocation for the coroutine frame (NOTE; the actual size
     computation is deferred until late in the middle end to allow for future
     optimisations that will be allowed to elide unused frame entries).
     We build the return object.

   D Build and expand the actor and destroyer function bodies.
     The destroyer is a trivial shim that sets a bit to indicate that the
     destroy dispatcher should be used and then calls into the actor.

     The actor function is the implementation of the user's state machine.
     The current suspend point is noted in an index.
     Each suspend point is encoded as a pair of internal functions, one in
     the relevant dispatcher, and one representing the suspend point.

     During this process, the user's local variables and the proxies for the
     self-handle and the promise class instanceare re-written to their
     coroutine frame equivalents.

     The complete bodies for the ramp, actor and destroy function are passed
     back to finish_function for folding and gimplification.

[C++ coroutines 4] Middle end expanders and transforms.

The first part of this is a pass that provides:
 * expansion of the library support builtins, these are simple boolean
   or numerical substitutions.

 * The functionality of implementing an exit from scope without cleanup
   is performed here by lowering an IFN to a gimple goto.

This pass has to run for non-coroutine functions, since functions calling
the builtins are not necessarily coroutines (i.e. they are implementing the
library interfaces which may be called from anywhere).

The second part is the expansion of the coroutine IFNs that describe the
state machine connections to the dispatchers.  This only has to be run
for functions that are coroutine components.  The work done by this pass
is:

   In the front end we construct a single actor function that contains
   the coroutine state machine.

   The actor function has three entry conditions:
    1. from the ramp, resume point 0 - to initial-suspend.
    2. when resume () is executed (resume point N).
    3. from the destroy () shim when that is executed.

   The actor function begins with two dispatchers; one for resume and
   one for destroy (where the initial entry from the ramp is a special-
   case of resume point 0).

   Each suspend point and each dispatch entry is marked with an IFN such
   that we can connect the relevant dispatchers to their target labels.

   So, if we have:

   CO_YIELD (NUM, FINAL, RES_LAB, DEST_LAB, FRAME_PTR)

   This is await point NUM, and is the final await if FINAL is non-zero.
   The resume point is RES_LAB, and the destroy point is DEST_LAB.

   We expect to find a CO_ACTOR (NUM) in the resume dispatcher and a
   CO_ACTOR (NUM+1) in the destroy dispatcher.

   Initially, the intent of keeping the resume and destroy paths together
   is that the conditionals controlling them are identical, and thus there
   would be duplication of any optimisation of those paths if the split
   were earlier.

   Subsequent inlining of the actor (and DCE) is then able to extract the
   resume and destroy paths as separate functions if that is found
   profitable by the optimisers.

   Once we have remade the connections to their correct postions, we elide
   the labels that the front end inserted.

[C++ coroutines 5] Standard library header.

This provides the interfaces mandated by the standard and implements
the interaction with the coroutine frame by means of inline use of
builtins expanded at compile-time.  There should be a 1:1 correspondence
with the standard sections which are cross-referenced.

There is no runtime content.

At this stage, we have the content in an inline namespace "__n4835" for
the CD we worked to.

[C++ coroutines 6] Testsuite.

There are two categories of test:

1. Checks for correctly formed source code and the error reporting.
2. Checks for transformation and code-gen.

The second set are run as 'torture' tests for the standard options
set, including LTO.  These are also intentionally run with no options
provided (from the coroutines.exp script).

gcc/ChangeLog:

2020-01-18  Iain Sandoe  <iain@sandoe.co.uk>

	* Makefile.in: Add coroutine-passes.o.
	* builtin-types.def (BT_CONST_SIZE): New.
	(BT_FN_BOOL_PTR): New.
	(BT_FN_PTR_PTR_CONST_SIZE_BOOL): New.
	* builtins.def (DEF_COROUTINE_BUILTIN): New.
	* coroutine-builtins.def: New file.
	* coroutine-passes.cc: New file.
	* function.h (struct GTY function): Add a bit to indicate that the
	function is a coroutine component.
	* internal-fn.c (expand_CO_FRAME): New.
	(expand_CO_YIELD): New.
	(expand_CO_SUSPN): New.
	(expand_CO_ACTOR): New.
	* internal-fn.def (CO_ACTOR): New.
	(CO_YIELD): New.
	(CO_SUSPN): New.
	(CO_FRAME): New.
	* passes.def: Add pass_coroutine_lower_builtins,
	pass_coroutine_early_expand_ifns.
	* tree-pass.h (make_pass_coroutine_lower_builtins): New.
	(make_pass_coroutine_early_expand_ifns): New.
	* doc/invoke.texi: Document the fcoroutines command line
	switch.

gcc/c-family/ChangeLog:

2020-01-18  Iain Sandoe  <iain@sandoe.co.uk>

	* c-common.c (co_await, co_yield, co_return): New.
	* c-common.h (RID_CO_AWAIT, RID_CO_YIELD,
	RID_CO_RETURN): New enumeration values.
	(D_CXX_COROUTINES): Bit to identify coroutines are active.
	(D_CXX_COROUTINES_FLAGS): Guard for coroutine keywords.
	* c-cppbuiltin.c (__cpp_coroutines): New cpp define.
	* c.opt (fcoroutines): New command-line switch.

gcc/cp/ChangeLog:

2020-01-18  Iain Sandoe  <iain@sandoe.co.uk>

	* Make-lang.in: Add coroutines.o.
	* cp-tree.h (lang_decl-fn): coroutine_p, new bit.
	(DECL_COROUTINE_P): New.
	* lex.c (init_reswords): Enable keywords when the coroutine flag
	is set,
	* operators.def (co_await): New operator.
	* call.c (add_builtin_candidates): Handle CO_AWAIT_EXPR.
	(op_error): Likewise.
	(build_new_op_1): Likewise.
	(build_new_function_call): Validate coroutine builtin arguments.
	* constexpr.c (potential_constant_expression_1): Handle
	CO_AWAIT_EXPR, CO_YIELD_EXPR, CO_RETURN_EXPR.
	* coroutines.cc: New file.
	* cp-objcp-common.c (cp_common_init_ts): Add CO_AWAIT_EXPR,
	CO_YIELD_EXPR, CO_RETRN_EXPR as TS expressions.
	* cp-tree.def (CO_AWAIT_EXPR, CO_YIELD_EXPR, (CO_RETURN_EXPR): New.
	* cp-tree.h (coro_validate_builtin_call): New.
	* decl.c (emit_coro_helper): New.
	(finish_function): Handle the case when a function is found to
	be a coroutine, perform the outlining and emit the outlined
	functions. Set a bit to signal that this is a coroutine component.
	* parser.c (enum required_token): New enumeration RT_CO_YIELD.
	(cp_parser_unary_expression): Handle co_await.
	(cp_parser_assignment_expression): Handle co_yield.
	(cp_parser_statement): Handle RID_CO_RETURN.
	(cp_parser_jump_statement): Handle co_return.
	(cp_parser_operator): Handle co_await operator.
	(cp_parser_yield_expression): New.
	(cp_parser_required_error): Handle RT_CO_YIELD.
	* pt.c (tsubst_copy): Handle CO_AWAIT_EXPR.
	(tsubst_expr): Handle CO_AWAIT_EXPR, CO_YIELD_EXPR and
	CO_RETURN_EXPRs.
	* tree.c (cp_walk_subtrees): Likewise.

libstdc++-v3/ChangeLog:

2020-01-18  Iain Sandoe  <iain@sandoe.co.uk>

	* include/Makefile.am: Add coroutine to the std set.
	* include/Makefile.in: Regenerated.
	* include/std/coroutine: New file.

gcc/testsuite/ChangeLog:

2020-01-18  Iain Sandoe  <iain@sandoe.co.uk>

	* g++.dg/coroutines/co-await-syntax-00-needs-expr.C: New test.
	* g++.dg/coroutines/co-await-syntax-01-outside-fn.C: New test.
	* g++.dg/coroutines/co-await-syntax-02-outside-fn.C: New test.
	* g++.dg/coroutines/co-await-syntax-03-auto.C: New test.
	* g++.dg/coroutines/co-await-syntax-04-ctor-dtor.C: New test.
	* g++.dg/coroutines/co-await-syntax-05-constexpr.C: New test.
	* g++.dg/coroutines/co-await-syntax-06-main.C: New test.
	* g++.dg/coroutines/co-await-syntax-07-varargs.C: New test.
	* g++.dg/coroutines/co-await-syntax-08-lambda-auto.C: New test.
	* g++.dg/coroutines/co-return-syntax-01-outside-fn.C: New test.
	* g++.dg/coroutines/co-return-syntax-02-outside-fn.C: New test.
	* g++.dg/coroutines/co-return-syntax-03-auto.C: New test.
	* g++.dg/coroutines/co-return-syntax-04-ctor-dtor.C: New test.
	* g++.dg/coroutines/co-return-syntax-05-constexpr-fn.C: New test.
	* g++.dg/coroutines/co-return-syntax-06-main.C: New test.
	* g++.dg/coroutines/co-return-syntax-07-vararg.C: New test.
	* g++.dg/coroutines/co-return-syntax-08-bad-return.C: New test.
	* g++.dg/coroutines/co-return-syntax-09-lambda-auto.C: New test.
	* g++.dg/coroutines/co-yield-syntax-00-needs-expr.C: New test.
	* g++.dg/coroutines/co-yield-syntax-01-outside-fn.C: New test.
	* g++.dg/coroutines/co-yield-syntax-02-outside-fn.C: New test.
	* g++.dg/coroutines/co-yield-syntax-03-auto.C: New test.
	* g++.dg/coroutines/co-yield-syntax-04-ctor-dtor.C: New test.
	* g++.dg/coroutines/co-yield-syntax-05-constexpr.C: New test.
	* g++.dg/coroutines/co-yield-syntax-06-main.C: New test.
	* g++.dg/coroutines/co-yield-syntax-07-varargs.C: New test.
	* g++.dg/coroutines/co-yield-syntax-08-needs-expr.C: New test.
	* g++.dg/coroutines/co-yield-syntax-09-lambda-auto.C: New test.
	* g++.dg/coroutines/coro-builtins.C: New test.
	* g++.dg/coroutines/coro-missing-gro.C: New test.
	* g++.dg/coroutines/coro-missing-promise-yield.C: New test.
	* g++.dg/coroutines/coro-missing-ret-value.C: New test.
	* g++.dg/coroutines/coro-missing-ret-void.C: New test.
	* g++.dg/coroutines/coro-missing-ueh-1.C: New test.
	* g++.dg/coroutines/coro-missing-ueh-2.C: New test.
	* g++.dg/coroutines/coro-missing-ueh-3.C: New test.
	* g++.dg/coroutines/coro-missing-ueh.h: New test.
	* g++.dg/coroutines/coro-pre-proc.C: New test.
	* g++.dg/coroutines/coro.h: New file.
	* g++.dg/coroutines/coro1-ret-int-yield-int.h: New file.
	* g++.dg/coroutines/coroutines.exp: New file.
	* g++.dg/coroutines/torture/alloc-00-gro-on-alloc-fail.C: New test.
	* g++.dg/coroutines/torture/alloc-01-overload-newdel.C: New test.
	* g++.dg/coroutines/torture/call-00-co-aw-arg.C: New test.
	* g++.dg/coroutines/torture/call-01-multiple-co-aw.C: New test.
	* g++.dg/coroutines/torture/call-02-temp-co-aw.C: New test.
	* g++.dg/coroutines/torture/call-03-temp-ref-co-aw.C: New test.
	* g++.dg/coroutines/torture/class-00-co-ret.C: New test.
	* g++.dg/coroutines/torture/class-01-co-ret-parm.C: New test.
	* g++.dg/coroutines/torture/class-02-templ-parm.C: New test.
	* g++.dg/coroutines/torture/class-03-operator-templ-parm.C: New test.
	* g++.dg/coroutines/torture/class-04-lambda-1.C: New test.
	* g++.dg/coroutines/torture/class-05-lambda-capture-copy-local.C: New test.
	* g++.dg/coroutines/torture/class-06-lambda-capture-ref.C: New test.
	* g++.dg/coroutines/torture/co-await-00-trivial.C: New test.
	* g++.dg/coroutines/torture/co-await-01-with-value.C: New test.
	* g++.dg/coroutines/torture/co-await-02-xform.C: New test.
	* g++.dg/coroutines/torture/co-await-03-rhs-op.C: New test.
	* g++.dg/coroutines/torture/co-await-04-control-flow.C: New test.
	* g++.dg/coroutines/torture/co-await-05-loop.C: New test.
	* g++.dg/coroutines/torture/co-await-06-ovl.C: New test.
	* g++.dg/coroutines/torture/co-await-07-tmpl.C: New test.
	* g++.dg/coroutines/torture/co-await-08-cascade.C: New test.
	* g++.dg/coroutines/torture/co-await-09-pair.C: New test.
	* g++.dg/coroutines/torture/co-await-10-template-fn-arg.C: New test.
	* g++.dg/coroutines/torture/co-await-11-forwarding.C: New test.
	* g++.dg/coroutines/torture/co-await-12-operator-2.C: New test.
	* g++.dg/coroutines/torture/co-await-13-return-ref.C: New test.
	* g++.dg/coroutines/torture/co-ret-00-void-return-is-ready.C: New test.
	* g++.dg/coroutines/torture/co-ret-01-void-return-is-suspend.C: New test.
	* g++.dg/coroutines/torture/co-ret-03-different-GRO-type.C: New test.
	* g++.dg/coroutines/torture/co-ret-04-GRO-nontriv.C: New test.
	* g++.dg/coroutines/torture/co-ret-05-return-value.C: New test.
	* g++.dg/coroutines/torture/co-ret-06-template-promise-val-1.C: New test.
	* g++.dg/coroutines/torture/co-ret-07-void-cast-expr.C: New test.
	* g++.dg/coroutines/torture/co-ret-08-template-cast-ret.C: New test.
	* g++.dg/coroutines/torture/co-ret-09-bool-await-susp.C: New test.
	* g++.dg/coroutines/torture/co-ret-10-expression-evaluates-once.C: New test.
	* g++.dg/coroutines/torture/co-ret-11-co-ret-co-await.C: New test.
	* g++.dg/coroutines/torture/co-ret-12-co-ret-fun-co-await.C: New test.
	* g++.dg/coroutines/torture/co-ret-13-template-2.C: New test.
	* g++.dg/coroutines/torture/co-ret-14-template-3.C: New test.
	* g++.dg/coroutines/torture/co-yield-00-triv.C: New test.
	* g++.dg/coroutines/torture/co-yield-01-multi.C: New test.
	* g++.dg/coroutines/torture/co-yield-02-loop.C: New test.
	* g++.dg/coroutines/torture/co-yield-03-tmpl.C: New test.
	* g++.dg/coroutines/torture/co-yield-04-complex-local-state.C: New test.
	* g++.dg/coroutines/torture/co-yield-05-co-aw.C: New test.
	* g++.dg/coroutines/torture/co-yield-06-fun-parm.C: New test.
	* g++.dg/coroutines/torture/co-yield-07-template-fn-param.C: New test.
	* g++.dg/coroutines/torture/co-yield-08-more-refs.C: New test.
	* g++.dg/coroutines/torture/co-yield-09-more-templ-refs.C: New test.
	* g++.dg/coroutines/torture/coro-torture.exp: New file.
	* g++.dg/coroutines/torture/exceptions-test-0.C: New test.
	* g++.dg/coroutines/torture/func-params-00.C: New test.
	* g++.dg/coroutines/torture/func-params-01.C: New test.
	* g++.dg/coroutines/torture/func-params-02.C: New test.
	* g++.dg/coroutines/torture/func-params-03.C: New test.
	* g++.dg/coroutines/torture/func-params-04.C: New test.
	* g++.dg/coroutines/torture/func-params-05.C: New test.
	* g++.dg/coroutines/torture/func-params-06.C: New test.
	* g++.dg/coroutines/torture/lambda-00-co-ret.C: New test.
	* g++.dg/coroutines/torture/lambda-01-co-ret-parm.C: New test.
	* g++.dg/coroutines/torture/lambda-02-co-yield-values.C: New test.
	* g++.dg/coroutines/torture/lambda-03-auto-parm-1.C: New test.
	* g++.dg/coroutines/torture/lambda-04-templ-parm.C: New test.
	* g++.dg/coroutines/torture/lambda-05-capture-copy-local.C: New test.
	* g++.dg/coroutines/torture/lambda-06-multi-capture.C: New test.
	* g++.dg/coroutines/torture/lambda-07-multi-yield.C: New test.
	* g++.dg/coroutines/torture/lambda-08-co-ret-parm-ref.C: New test.
	* g++.dg/coroutines/torture/local-var-0.C: New test.
	* g++.dg/coroutines/torture/local-var-1.C: New test.
	* g++.dg/coroutines/torture/local-var-2.C: New test.
	* g++.dg/coroutines/torture/local-var-3.C: New test.
	* g++.dg/coroutines/torture/local-var-4.C: New test.
	* g++.dg/coroutines/torture/mid-suspend-destruction-0.C: New test.
	* g++.dg/coroutines/torture/pr92933.C: New test.

Bootstrap found yet another unused variable:
../../gcc/config/arm/vfp.md:1651:17: warning: unused variable 'regname' [-Wunused-variable]

2020-01-18  Jakub Jelinek  <jakub@redhat.com>

	* config/arm/vfp.md (*clear_vfp_multiple): Remove unused variable.

As reported in PR93312, the:
> > > > > >         * config/arm/arm.c (clear_operation_p): New function.
change broke RTL checking bootstrap.

On the testcase from the PR (which is distilled from libgcc2.c, so I think
we don't need to add it into testsuite) we ICE because SET_DEST (elt) is
not a REG, but SUBREG.  The code uses REGNO on it, which is invalid, but
only stores it into a variable, then performs REG_P (reg) check,
determines it is not a REG and bails early.

The following patch just moves the regno variable initialization after that
check, it isn't used in between.  And, as a small optimization, because
reg doesn't change, doesn't use REGNO (reg) a second time to set last_regno.

2020-01-18  Jakub Jelinek  <jakub@redhat.com>

	PR target/93312
	* config/arm/arm.c (clear_operation_p): Don't use REGNO until
	after checking the argument is a REG.  Don't use REGNO (reg)
	again to set last_regno, reuse regno variable instead.

	PR libfortran/93234
	* io/unit.c (set_internal_unit): Set round and sign flags
	correctly.

	* gfortran.dg/inquire_pre.f90: New test.

PR analyzer/93290 reports an ICE on calls to isnan().
The root cause is that an UNORDERED_EXPR is passed
to region_model::eval_condition_without_cm, and there's
a stray gcc_unreachable () in the case where we're comparing
an svalue against itself.

I attempted a more involved patch that properly handled NaN in general
but it seems I've baked the assumption of reflexivity too deeply into
the constraint_manager code.

For now, this patch avoids the ICE and documents the limitation.

gcc/analyzer/ChangeLog:
	PR analyzer/93290
	* region-model.cc (region_model::eval_condition_without_cm): Avoid
	gcc_unreachable for unexpected operations for the case where
	we're comparing an svalue against itself.

gcc/ChangeLog
	* doc/analyzer.texi (Limitations): Add note about NaN.

gcc/testsuite/ChangeLog:
	PR analyzer/93290
	* gcc.dg/analyzer/pr93290.c: New test.

	PR libfortran/90374
	* io/format.c (parse_format_list): Zero width not allowed with
	FMT_D.
	* io/write_float.def (build_float_string): Include range of
	higher exponent values that require wider width.

	PR c++/92542
	* g++.dg/pr92542.C: New.

	PR c++/92542
	* g++.dg/pr92542.C: New.