This changes libcc1 to use "override" where appropriate.

libcc1

	* libcp1.cc (class compiler_triplet_regexp)
	(class compiler_driver_filename, class libcp1_connection): Use
	"override".
	* libcc1.cc (class compiler_triplet_regexp)
	(class compiler_driver_filename, class libcc1_connection): Use
	"override".

Now that C++11 can be used in GCC, libcc1 can be changed to use
templates and type traits to handle unmarshalling all kinds of enums.

libcc1

	* marshall.hh (cc1_plugin::unmarshall): Use type traits.
	* marshall-cp.hh (cc1_plugin::unmarshall): Remove overloads.
	* marshall-c.hh: Remove.
	* libcc1plugin.cc: Update includes.
	* libcc1.cc: Update includes.

for  libstdc++-v3/ChangeLog

	* acinclude.m4: Add VxWorks-specific case for the
	configuration of ctypes.
	* configure: Regenerate.
	* config/locale/vxworks/ctype_members.cc: Add VxWorks-specific
	version.
	* config/os/vxworks/ctype_base.h: Adjust for VxWorks7+.
	* config/os/vxworks/ctype_configure_char.cc: Likewise.
	* config/os/vxworks/ctype_inline.h: Likewise.
	* testsuite/28_regex/traits/char/isctype.cc: Defines
	NEWLINE_IN_CLASS_BLANK if the target is VxWorks.
	* testsuite/28_regex/traits/wchar_t/isctype.cc: Likewise.

x86-vx7r2 needs svr4_dbx_register_map, but the default in i386/i386.h
was dbx_register_map, partially swapping ebp and esp in unwind info.

i386/vxworks.h had a correct overrider, but it was conditional for
vxworks < 7.  This patch reenables the overrider unconditionally.


for  gcc/ChangeLog

	* config/i386/vxworks.h (DBX_REGISTER_NUMBER): Make it
	unconditional.

This fixes some ubsan errors in std::promise:

future:1153:34: runtime error: member call on null pointer of type 'struct element_type'
future:1153:34: runtime error: member access within null pointer of type 'struct element_type'

The problem is that the check for a null pointer is done inside the
_State::__Setter function, which is only evaluated after evaluating the
_M_future->_M_set_result postfix-expression.

This change adds a new promise::_M_state() helper for accessing
_M_future, and moves the check for no shared state into there, instead
of inside the __setter functions. The __setter functions are made
always_inline, to avoid the situation where the linker selects the old
version of set_value (without the _S_check call) and the new version of
__setter (without the _S_check call) and so there is no check. With the
always_inline attribute the old version of set_value will either inline
the old __setter or call an extern definition of it, and the new
set_value will do the check itself, so both versions do the check.

libstdc++-v3/ChangeLog:

	* include/std/future (promise::set_value): Check for existence
	of shared state before dereferncing it.
	(promise::set_exception, promise::set_value_at_thread_exit)
	(promise::set_exception_at_thread_exit): Likewise.
	(promise<R&>::set_value, promise<R&>::set_exception)
	(promise<R&>::set_value_at_thread_exit)
	(promise<R&>::set_exception_at_thread_exit): Likewise.
	(promise<void>::set_value, promise<void>::set_exception)
	(promise<void>::set_value_at_thread_exit)
	(promise<void>::set_exception_at_thread_exit): Likewise.
	* testsuite/30_threads/promise/members/at_thread_exit2.cc:
	Remove unused variable.

This fixes a ubsan error when constructing a string with a null pointer:

bits/basic_string.h:534:21: runtime error: applying non-zero offset 18446744073709551615 to null pointer

The _M_construct function only cares whether the second pointer is
non-null, so create a non-null value without undefined arithmetic.

We can also pass the random_access_iterator_tag directly to the
_M_construct function, to avoid going via the tag dispatching
_M_construct_aux, because we know we have pointers not integers here.

libstdc++-v3/ChangeLog:

	* include/bits/basic_string.h (basic_string(const CharT*, const A&)):
	Do not do arithmetic on null pointer.

This fixes ubsan errors:

ext/pb_ds/detail/cc_hash_table_map_/cc_ht_map_.hpp:533:15: runtime error: member access within null pointer of type 'struct entry'

libstdc++-v3/ChangeLog:

	* include/ext/pb_ds/detail/cc_hash_table_map_/cc_ht_map_.hpp
	(find_key_pointer(key_const_reference, false_type))
	(find_key_pointer(key_const_reference, true_type)): Do not
	dereference null pointer.

Fix some test bugs found by ubsan.

libstdc++-v3/ChangeLog:

	* testsuite/20_util/from_chars/3.cc: Use unsigned type to avoid
	overflow.
	* testsuite/24_iterators/reverse_iterator/2.cc: Do not add
	non-zero value to null pointer.
	* testsuite/25_algorithms/copy_backward/move_iterators/69478.cc:
	Use past-the-end iterator for result.
	* testsuite/25_algorithms/move_backward/69478.cc: Likewise.
	* testsuite/25_algorithms/move_backward/93872.cc: Likewise.

AIX XCOFF symbols can be labels or qualnames (names with an appended
mapping class).  CSECTs must be declared with a mapping class.
Within an assembler file, the symbol names with and without the mapping
class are unique.  An object file symbol table only presents the symbol
name without the mapping class, but the section of the symbol depends on
the mapping class.

The AIX XCOFF assembly language does not support first class aliases.
GCC implements symbol aliases by emitting additional labels for the function
or object.  When GCC encodes sections for a DECL, it must distinguish
between the primary definition and the aliases, which don't have a
mapping class encoding.

	.globl foo[DS]
	.globl .foo
	.globl foo1
	.globl .foo1
	.csect foo[DS]
foo:
foo1:
	.long .foo, TOC[tc0] 0
	.csect .foo[PR]
.foo:
.foo1:

The CSECT foo[DS] and label foo are distinct.  foo1 is another label (alias)
for foo, and .foo1 is another label (alias) for .foo.  foo is the function
descriptor and .foo is the code.

This patch adds the [DS] mapping class to the encoding of FUNCTION_DECL
but ensures that mapping class is not added to function aliases.

rs6000_output_mi_thunk is updated to emit the function name that matches
the behavior of GCC final.c for normal functions: get_fnname_from_decl based
on the RTL name, not the DECL name.

	* config/rs6000/rs6000-call.c (rs6000_output_mi_thunk): Use
	get_fnname_from_decl for name of thunk.
	* config/rs6000/rs6000.c (rs6000_declare_alias): Use assemble_name
	and ASM_OUTPUT_LABEL.
	(rs6000_xcoff_declare_function_name): Use assemble_name and
	ASM_OUTPUT_LABEL.
	(rs6000_xcoff_declare_object_name): Use ASM_OUTPUT_LABEL.
	(rs6000_xcoff_encode_section_info): Don't add mapping class
	for aliases.  Always add [DS] mapping class to primary
	FUNCTION_DECL.
	(rs6000_asm_weaken_decl): Don't explicitly add [DS].

gcc/ChangeLog:

	PR middle-end/100307
	* builtins.c (compute_objsize_r): Clear base0 for pointers.

gcc/testsuite/ChangeLog:

	PR middle-end/100307
	* g++.dg/warn/Wplacement-new-size-9.C: New test.
	* gcc.dg/tree-ssa/builtin-sprintf-warn-26.c: New test.

gcc/testsuite/ChangeLog:
	* gcc.dg/Wvla-parameter-3.c: Use unique strings in directive names.

gcc/testsuite/ChangeLog:
	* gcc.dg/Wvla-parameter-2.c: Use unique strings in directive names.

gcc/
	* config/bfin/bfin.h (NOTICE_UPDATE_CC): Remove.

Checking for an osc break is somewhat brittle especially with many
passes potentially introducing new insns and moving them around.
Therefore, only compile the test with -O1 -fschedule-insns in order
to limit the influence of other passes.

gcc/testsuite/ChangeLog:

	* gcc.target/s390/oscbreak-1.c: Compile with -O1
	-fschedule-insns

This removes CC0 and all directly related infrastructure.

CC_STATUS, CC_STATUS_MDEP, CC_STATUS_MDEP_INIT, and NOTICE_UPDATE_CC
are deleted and poisoned.  CC0 is only deleted (some targets use that
name for something else).  HAVE_cc0 is automatically generated, and we
no longer will do that after this patch.

CC_STATUS_INIT is suggested in final.c to also be useful for ports that
are not CC0, and at least arm seems to use it for something.  So I am
leaving that alone, but most targets that have it could remove it.

2021-05-04  Segher Boessenkool  <segher@kernel.crashing.org>

	* caller-save.c: Remove CC0.
	* cfgcleanup.c: Remove CC0.
	* cfgrtl.c: Remove CC0.
	* combine.c: Remove CC0.
	* compare-elim.c: Remove CC0.
	* conditions.h: Remove CC0.
	* config/h8300/h8300.h: Remove CC0.
	* config/h8300/h8300-protos.h: Remove CC0.
	* config/h8300/peepholes.md: Remove CC0.
	* config/i386/x86-tune-sched.c: Remove CC0.
	* config/m68k/m68k.c: Remove CC0.
	* config/rl78/rl78.c: Remove CC0.
	* config/sparc/sparc.c: Remove CC0.
	* config/xtensa/xtensa.c: Remove CC0.
	(gen_conditional_move):  Use pc_rtx instead of cc0_rtx in a piece of
	RTL where that is used as a placeholder only.
	* cprop.c: Remove CC0.
	* cse.c: Remove CC0.
	* cselib.c: Remove CC0.
	* df-problems.c: Remove CC0.
	* df-scan.c: Remove CC0.
	* doc/md.texi: Remove CC0.  Adjust an example.
	* doc/rtl.texi: Remove CC0.  Adjust an example.
	* doc/tm.texi: Regenerate.
	* doc/tm.texi.in: Remove CC0.
	* emit-rtl.c: Remove CC0.
	* final.c: Remove CC0.
	* fwprop.c: Remove CC0.
	* gcse-common.c: Remove CC0.
	* gcse.c: Remove CC0.
	* genattrtab.c: Remove CC0.
	* genconfig.c: Remove CC0.
	* genemit.c: Remove CC0.
	* genextract.c: Remove CC0.
	* gengenrtl.c: Remove CC0.
	* genrecog.c: Remove CC0.
	* haifa-sched.c: Remove CC0.
	* ifcvt.c: Remove CC0.
	* ira-costs.c: Remove CC0.
	* ira.c: Remove CC0.
	* jump.c: Remove CC0.
	* loop-invariant.c: Remove CC0.
	* lra-constraints.c: Remove CC0.
	* lra-eliminations.c: Remove CC0.
	* optabs.c: Remove CC0.
	* postreload-gcse.c: Remove CC0.
	* postreload.c: Remove CC0.
	* print-rtl.c: Remove CC0.
	* read-rtl-function.c: Remove CC0.
	* reg-notes.def: Remove CC0.
	* reg-stack.c: Remove CC0.
	* reginfo.c: Remove CC0.
	* regrename.c: Remove CC0.
	* reload.c: Remove CC0.
	* reload1.c: Remove CC0.
	* reorg.c: Remove CC0.
	* resource.c: Remove CC0.
	* rtl.c: Remove CC0.
	* rtl.def: Remove CC0.
	* rtl.h: Remove CC0.
	* rtlanal.c: Remove CC0.
	* sched-deps.c: Remove CC0.
	* sched-rgn.c: Remove CC0.
	* shrink-wrap.c: Remove CC0.
	* simplify-rtx.c: Remove CC0.
	* system.h: Remove CC0.  Poison NOTICE_UPDATE_CC, CC_STATUS_MDEP_INIT,
	CC_STATUS_MDEP, and CC_STATUS.
	* target.def: Remove CC0.
	* valtrack.c: Remove CC0.
	* var-tracking.c: Remove CC0.

phiopt now has dominator queries but fails to compute dominance
info.

2021-05-04  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/100414
	* tree-ssa-phiopt.c (get_non_trapping): Do not compute dominance
	info here.
	(tree_ssa_phiopt_worker): But unconditionally here.

	* gcc.dg/pr100414.c: New testcase.

C/C++ permit logical AND and logical OR also with floating-point or complex
arguments by doing an unequal zero comparison; the result is an 'int' with
value one or zero.  Hence, those are also permitted as reduction variable,
even though it is not the most sensible thing to do.

gcc/c/ChangeLog:

	* c-typeck.c (c_finish_omp_clauses): Accept float + complex
	for || and && reductions.

gcc/cp/ChangeLog:

	* semantics.c (finish_omp_reduction_clause): Accept float + complex
	for || and && reductions.

gcc/ChangeLog:

	* omp-low.c (lower_rec_input_clauses, lower_reduction_clauses): Handle
	&& and || with floating-point and complex arguments.

gcc/testsuite/ChangeLog:

	* gcc.dg/gomp/clause-1.c: Use 'reduction(&:..)' instead of '...(&&:..)'.

libgomp/ChangeLog:

	* testsuite/libgomp.c-c++-common/reduction-1.c: New test.
	* testsuite/libgomp.c-c++-common/reduction-2.c: New test.
	* testsuite/libgomp.c-c++-common/reduction-3.c: New test.

2021-05-04  Nick Clifton  <nickc@redhat.com>

	* configure.ac (AC_PROG_CC): Replace with AC_PROG_CC_C99.
	* configure: Regenerate.

This avoids errors outside the immediate context when std::visit is an
overload candidate because of ADL, but not actually viable.

The solution is to give std::visit a non-deduced return type. New
helpers are introduced for that, and existing ones refactored slightly.

libstdc++-v3/ChangeLog:

	PR libstdc++/100384
	* include/std/variant (__get_t): New alias template yielding the
	return type of std::get<N> on a variant.
	(__visit_result_t): New alias template yielding the result of
	std::visit.
	(__same_types): Move into namespace __detail::__variant.
	(__check_visitor_results): Likewise. Use __invoke_result_t and
	__get_t.
	(__check_visitor_result): Remove.
	(visit): Use __visit_result_t for return type.
	* testsuite/20_util/variant/100384.cc: New test.

We don't need to decide whether to use __int128 when running configure,
we can do so at compilation time by seeing if __SIZEOF_INT128__ is
defined and if it's greater than __SIZEOF_LONG_LONG__.

This removes another unnecessary architecture-specific config macro in
<bits/c++config.h>, so the same header can work for 32-bit or 64-bit
compilation on AIX.

libstdc++-v3/ChangeLog:

	* acinclude.m4 (GLIBCXX_ENABLE_INT128_FLOAT128): Remove
	checks for __int128 and rename to GLIBCXX_ENABLE_FLOAT128.
	* config.h.in: Regenerate.
	* configure: Regenerate.
	* configure.ac: Adjust to use GLIBCXX_ENABLE_FLOAT128.
	* include/bits/random.h (_Select_uint_least_t<s, 1>):
	Use __SIZEOF_INT128__ to decide whether to use __int128.
	* include/std/charconv (__to_chars_unsigned_type): Likewise.

When a call to a function is inlined and takes a parameter whose type is not
gimple_reg, a local variable is created in the caller to hold a copy of the
argument passed in the call with the following comment:

      /* We may produce non-gimple trees by adding NOPs or introduce
         invalid sharing when operand is not really constant.
         It is not big deal to prohibit constant propagation here as
         we will constant propagate in DOM1 pass anyway.  *

Of course the second sentence of the comment does not apply to non-gimple_reg
values, unless they get SRAed later, because we don't do constant propagation
for them.  This for example prevents two identical calls to a pure function
from being merged in the attached Ada testcase.

Therefore the attached patch attempts to reuse a read-only or non-addressable
local DECL of the caller, the hitch being that expand_call_inline needs to be
prevented from creating a CLOBBER for the case where it ends uo being reused.

gcc/
	* tree-inline.c (insert_debug_decl_map): Delete.
	(copy_debug_stmt): Minor tweak.
	(setup_one_parameter): Do not use a variable if the value is either
	a read-only DECL or a non-addressable local variable in the caller.
	In this case, insert the debug-only variable in the map manually.
	(expand_call_inline): Do not generate a CLOBBER for these values.
	* tree-inline.h (debug_map): Minor tweak.

The test for the presence of variables (really symbols) does not work
when you add -Ox -flto to CFLAGS:

  for v in $vars; do
    AC_MSG_CHECKING([for $v])
    AC_CACHE_VAL(libiberty_cv_var_$v,
      [AC_LINK_IFELSE([AC_LANG_PROGRAM([[int *p;]],[[extern int $v [];
                                         p = $v;]])],
                      [eval "libiberty_cv_var_$v=yes"],
                      [eval "libiberty_cv_var_$v=no"])])
    if eval "test \"`echo '$libiberty_cv_var_'$v`\" = yes"; then
      AC_MSG_RESULT(yes)
      AC_DEFINE_UNQUOTED($n)
    else
      AC_MSG_RESULT(no)
    fi
  done

because the assignment to 'p' is optimized away by LTO.  This is visible
on MinGW platforms in the form of a link failure for sys_siglist.

There is another link failures for stpcpy: the symbol is both referenced
by libiberty's pex-win32.c and provided by libiberty's stpcpy.c, so it
needs to have a linkage to be resolved in LTO mode.

libiberty/
	* configure.ac: Make test for variables more robust.
	* configure: Regenerate.
gcc/
	* builtins.c (builtin_with_linkage_p): Return true for stp[n]cpy.
	* symtab.c (symtab_node::output_to_lto_symbol_table_p): Tidy up.

This restricts the testcase to the target where it exposes the
situation fixed with g:e9d297a1
which targets BIT_FIELD_REFs created by fold_truth_andor.

This avoids strange dejagnu limits with overly long target lists
and simplifies the tests.

2021-05-04  Richard Biener  <rguenther@suse.de>

	* gcc.dg/tree-ssa/ssa-dse-26.c: Skip on !lp64 targets,
	simplify dump scanning down to one case.

This avoids reassociating asm goto defs because we have no idea
on which outgoing edge to insert defs.

2021-05-04  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/100329
	* tree-ssa-reassoc.c (can_reassociate_p): Do not reassociate
	asm goto defs.
	(insert_stmt_after): Assert we're not running into asm goto.

	* gcc.dg/torture/pr100329.c: New testcase.

The following makes sure to preserve control altering stmts
when removing trivially dead stmts in DSE.

2021-05-04  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/100398
	* tree-ssa-dse.c (pass_dse::execute): Preserve control
	altering stmts.

	* gcc.dg/torture/pr100398.c: New testcase.

gcc/ada/

	* pprint.adb: Remove qualification of arbitrary calls to
	Sinfo.Expressions and Sinfo.Parameter_Associations.

gcc/ada/

	* pprint.adb (Expr_Name): Simplify with functional variant of
	UI_Image.

gcc/ada/

	* pprint.adb (To_Mixed): Removed.

gcc/ada/

	* pprint.adb (List_Name_Count): Change type from Integer to
	Natural.

gcc/ada/

	* pprint.adb (Expression_Image): Special case for
	expression-with-actions.

gcc/ada/

	* exp_ch4.adb (Expand_Concatenate): Remove the non-optimization.

gcc/ada/

	* lib-xref.adb (Generate_Reference_To_Formals): Remove dedicated
	branch for generic subprograms (they are now handled together
	with non-generic subprograms in the ELSE branch); replace a
	low-level Ekind membership test with a high-level call to
	Is_Access_Subprogram_Type.

gcc/ada/

	* sem_ch12.adb (Check_Abstract_Primitives): Match First_Formal
	with Next_Formal.
	* sem_ch6.adb (Is_Non_Overriding_Operation): Likewise.

gcc/ada/

	* sem_prag.adb (Collect_Global_Item): Iterate directly over
	formals.

gcc/ada/

	* sem_prag.ads (Collect_Subprogram_Inputs_Outputs): Update
	comment; this routine is no longer used by GNATprove.
	* sem_prag.adb (Find_Role): The IN parameter is on output only
	when it belongs to non-function; also, the otherwise constant
	object can only be written by a non-function.
	(Collect_Global_Item): The IN parameter can only be written when
	it belongs to non-function; also, unnest this check to make it
	easier to read.

gcc/ada/

	* libgnat/s-assert.ads (Assert_Failure): Now a renaming of
	Assertion_Error.
	* libgnat/a-assert.ads (Assertion_Error): Now a first class
	citizen.  Remove dependency on System.Assertions.
	* gcc-interface/a-assert.ads, gcc-interface/a-assert.adb: New.
	* gcc-interface/Make-lang.in (GNAT_ADA_OBJS, GNATBIND_OBJS): Add
	a-assert.o from gcc-interface.

gcc/ada/

	* erroutc.adb (Matches): Move spec...
	* erroutc.ads (Matches): ...here.

gcc/ada/

	* gnat1drv.adb (Adjust_Global_Switches): Force error marker in
	GNATprove mode.

gcc/ada/

	* binde.adb: No need for ??? marks in Binde, because it is
	superseded by Bindo.
	* bindo-writers.adb (Write_Unit_Closure): Verified that -Ra
	works.
	* exp_ch4.adb, sinfo.ads (Expand_N_Type_Conversion): Rules for
	conversions passed to gigi are documented in sinfo.ads.
	(Expand_N_Unchecked_Type_Conversion): Comment is a duplicate of
	one in sinfo.ads.
	(Expand_N_In): Robert already added sufficient comments years
	after the ??? comment was inserted.
	(Expand_Membership_Minimize_Eliminate_Overflow): I don't see any
	reason why Stand should export Long_Long_Integer'Base -- it
	doesn't export any other base types.
	(Size_In_Storage_Elements): We are doing an allocator, so we
	don't care about sizes in bits.
	(Expand_N_Allocator): PolyORB isn't going to be significantly
	improved, so we're not going to mess with remote access to
	class-wide types.
	(Optimize_Return_Stmt): It's not important to optimize return
	statements in predicate functions -- there are many
	more-important optimizations we could do. Keep part of the
	comment without "???", to clarify why the "and then ...".
	(User_Defined_Primitive_Equality_Op): The optimization doesn't
	seem important enough.
	(Expand_N_Unchecked_Type_Conversion): Refactor to use
	Expand_N_Unchecked_Expression.
	(Make_Array_Comparison_Op): This seems like a case of "it it's
	not broken, don't fix it". Too much risk of causing bugs.
	* debug_a.adb: Remove ??? comments asking why Current_Error_Node
	is maintained unconditionally, and add a comment explaining why.
	* errout.adb: These kinds of minor bugs do indeed exist, but
	we're never going to get around to fixing them "properly", so we
	need this code for robustness.
	* gnatchop.adb (Read_File): Document when read can fail.
	* gnatdll.adb (Parse_Command_Line): Nobody is complaining about
	these arbitrary limits, so no need to use Table. Increase the
	limits just in case.  It is clear from the names what they are
	limits on.
	* gnatlink.adb: Add needed comments.
	(Delete): An existing comment makes clear it's intentional, and
	it's been like that since 1996.
	(Process_Args): Improve comments.
	(Search_Library_Path): Refactoring to avoid deep nesting.
	* inline.adb (Build_Body_To_Inline): Probably won't get around
	to doing that optimization.
	(Is_Unit_Subprogram): No, this should not be moved to Sem_Aux,
	because it is too specialized to this context.
	(Do_Reset): No comment is needed here; it's clear from the
	comment on Reset_Dispatching_Calls. Do_Reset is an artificial
	subprogram; if we had proper iterators, it would just be an if
	statement in the loop.
	(Rewrite_Function_Call): Probably won't get around to doing that
	optimization.
	* layout.adb (Layout_Type): The gigi comment doesn't need to be
	a ??? comment, and it's been that way since 2000.  The
	limitation to scalars will likely never be investigated, and
	it's been that way since 2009.
	* lib.adb (Check_Same_Extended_Unit): This doesn't look like
	something that needs fixing; it looks like a permanent
	workaround.
	* lib-load.adb (Change_Main_Unit_To_Spec): It is good enough in
	practice.
	(Load_Unit): Nobody will ever get around to investigating the
	obscure PMES oddity, and the optimization is not worth the
	trouble.
	* live.adb: It's not worth documenting this. It is used only
	with a debug switch. Nobody who has done significant work on it
	is still around, so it would require substantial investigation.
	* mdll.ads: I see no reason for USE.
	* namet.ads: Routines are obsolete, but they're not going
	anywhere anytime soon (too much work, and surprisingly delicate
	because of dependences on global variables).
	* osint.ads: Minor.
	* osint.adb: Improve comments.
	(Full_Lib_File_Name): Use Smart_Find_File.