sjlj.S did not have the GNU property note markup and the BTI c
instructions that are necessary when it is built with branch
protection.
The notes are only added when libitm is built with branch
protection, because old linkers mishandle the note (merge
them incorrectly or emit warnings), the BTI instructions
are added unconditionally.
2020-07-09 Szabolcs Nagy <szabolcs.nagy@arm.com>
libitm/ChangeLog:
* config/aarch64/sjlj.S: Add BTI marking and related definitions,
and add BTI c to function entries.
lse.S did not have the GNU property note markup and the BTI c
instructions that are necessary when it is built with branch
protection.
The notes are only added when libgcc is built with branch
protection, because old linkers mishandle the note (merge
them incorrectly or emit warnings), the BTI instructions
are added unconditionally.
Note: BTI c is only necessary at function entry if the function
may be called indirectly, currently lse functions are not called
indirectly, but BTI is added for ABI reasons e.g. to allow
linkers later to emit stub code with indirect jump.
2020-07-09 Szabolcs Nagy <szabolcs.nagy@arm.com>
libgcc/ChangeLog:
PR target/96001
* config/aarch64/lse.S: Add BTI marking and related definitions,
and add BTI c to function entries.
lse.S did not have GNU stack note, this may cause missing
PT_GNU_STACK in binaries on Linux and FreeBSD.
2020-07-09 Szabolcs Nagy <szabolcs.nagy@arm.com>
libgcc/ChangeLog:
* config/aarch64/lse.S: Add stack note.
sjlj.S only had the note on Linux, but it is supposed
to have it on FreeBSD too.
2020-07-09 Szabolcs Nagy <szabolcs.nagy@arm.com>
libitm/ChangeLog:
* config/aarch64/sjlj.S: Add stack note if __FreeBSD__ is defined.
Define the __ARM_FEATURE_BTI_DEFAULT feature test
macro when BTI branch protection is enabled.
2020-07-09 Szabolcs Nagy <szabolcs.nagy@arm.com>
gcc/ChangeLog:
* config/aarch64/aarch64-c.c (aarch64_update_cpp_builtins): Add
__ARM_FEATURE_BTI_DEFAULT support.
This patch introduces the mitigation for Straight Line Speculation past
the BLR instruction.
This mitigation replaces BLR instructions with a BL to a stub which uses
a BR to jump to the original value. These function stubs are then
appended with a speculation barrier to ensure no straight line
speculation happens after these jumps.
When optimising for speed we use a set of stubs for each function since
this should help the branch predictor make more accurate predictions
about where a stub should branch.
When optimising for size we use one set of stubs for all functions.
This set of stubs can have human readable names, and we are using
`__call_indirect_x<N>` for register x<N>.
When BTI branch protection is enabled the BLR instruction can jump to a
`BTI c` instruction using any register, while the BR instruction can
only jump to a `BTI c` instruction using the x16 or x17 registers.
Hence, in order to ensure this transformation is safe we mov the value
of the original register into x16 and use x16 for the BR.
As an example when optimising for size:
a
BLR x0
instruction would get transformed to something like
BL __call_indirect_x0
where __call_indirect_x0 labels a thunk that contains
__call_indirect_x0:
MOV X16, X0
BR X16
<speculation barrier>
The first version of this patch used local symbols specific to a
compilation unit to try and avoid relocations.
This was mistaken since functions coming from the same compilation unit
can still be in different sections, and the assembler will insert
relocations at jumps between sections.
On any relocation the linker is permitted to emit a veneer to handle
jumps between symbols that are very far apart. The registers x16 and
x17 may be clobbered by these veneers.
Hence the function stubs cannot rely on the values of x16 and x17 being
the same as just before the function stub is called.
Similar can be said for the hot/cold partitioning of single functions,
so function-local stubs have the same restriction.
This updated version of the patch never emits function stubs for x16 and
x17, and instead forces other registers to be used.
Given the above, there is now no benefit to local symbols (since they
are not enough to avoid dealing with linker intricacies). This patch
now uses global symbols with hidden visibility each stored in their own
COMDAT section. This means stubs can be shared between compilation
units while still avoiding the PLT indirection.
This patch also removes the `__call_indirect_x30` stub (and
function-local equivalent) which would simply jump back to the original
location.
The function-local stubs are emitted to the assembly output file in one
chunk, which means we need not add the speculation barrier directly
after each one.
This is because we know for certain that the instructions directly after
the BR in all but the last function stub will be from another one of
these stubs and hence will not contain a speculation gadget.
Instead we add a speculation barrier at the end of the sequence of
stubs.
The global stubs are emitted in COMDAT/.linkonce sections by
themselves so that the linker can remove duplicates from multiple object
files. This means they are not emitted in one chunk, and each one must
include the speculation barrier.
Another difference is that since the global stubs are shared across
compilation units we do not know that all functions will be targeting an
architecture supporting the SB instruction.
Rather than provide multiple stubs for each architecture, we provide a
stub that will work for all architectures -- using the DSB+ISB barrier.
This mitigation does not apply for BLR instructions in the following
places:
- Some accesses to thread-local variables use a code sequence with a BLR
instruction. This code sequence is part of the binary interface between
compiler and linker. If this BLR instruction needs to be mitigated, it'd
probably be best to do so in the linker. It seems that the code sequence
for thread-local variable access is unlikely to lead to a Spectre Revalation
Gadget.
- PLT stubs are produced by the linker and each contain a BLR instruction.
It seems that at most only after the last PLT stub a Spectre Revalation
Gadget might appear.
Testing:
Bootstrap and regtest on AArch64
(with BOOT_CFLAGS="-mharden-sls=retbr,blr")
Used a temporary hack(1) in gcc-dg.exp to use these options on every
test in the testsuite, a slight modification to emit the speculation
barrier after every function stub, and a script to check that the
output never emitted a BLR, or unmitigated BR or RET instruction.
Similar on an aarch64-none-elf cross-compiler.
1) Temporary hack emitted a speculation barrier at the end of every stub
function, and used a script to ensure that:
a) Every RET or BR is immediately followed by a speculation barrier.
b) No BLR instruction is emitted by compiler.
gcc/ChangeLog:
* config/aarch64/aarch64-protos.h (aarch64_indirect_call_asm):
New declaration.
* config/aarch64/aarch64.c (aarch64_regno_regclass): Handle new
stub registers class.
(aarch64_class_max_nregs): Likewise.
(aarch64_register_move_cost): Likewise.
(aarch64_sls_shared_thunks): Global array to store stub labels.
(aarch64_sls_emit_function_stub): New.
(aarch64_create_blr_label): New.
(aarch64_sls_emit_blr_function_thunks): New.
(aarch64_sls_emit_shared_blr_thunks): New.
(aarch64_asm_file_end): New.
(aarch64_indirect_call_asm): New.
(TARGET_ASM_FILE_END): Use aarch64_asm_file_end.
(TARGET_ASM_FUNCTION_EPILOGUE): Use
aarch64_sls_emit_blr_function_thunks.
* config/aarch64/aarch64.h (STB_REGNUM_P): New.
(enum reg_class): Add STUB_REGS class.
(machine_function): Introduce `call_via` array for
function-local stub labels.
* config/aarch64/aarch64.md (*call_insn, *call_value_insn): Use
aarch64_indirect_call_asm to emit code when hardening BLR
instructions.
* config/aarch64/constraints.md (Ucr): New constraint
representing registers for indirect calls. Is GENERAL_REGS
usually, and STUB_REGS when hardening BLR instruction against
SLS.
* config/aarch64/predicates.md (aarch64_general_reg): STUB_REGS class
is also a general register.
gcc/testsuite/ChangeLog:
* gcc.target/aarch64/sls-mitigation/sls-miti-blr-bti.c: New test.
* gcc.target/aarch64/sls-mitigation/sls-miti-blr.c: New test.
Instructions following RET or BR are not necessarily executed. In order
to avoid speculation past RET and BR we can simply append a speculation
barrier.
Since these speculation barriers will not be architecturally executed,
they are not expected to add a high performance penalty.
The speculation barrier is to be SB when targeting architectures which
have this enabled, and DSB SY + ISB otherwise.
We add tests for each of the cases where such an instruction was seen.
This is implemented by modifying each machine description pattern that
emits either a RET or a BR instruction. We choose not to use something
like `TARGET_ASM_FUNCTION_EPILOGUE` since it does not affect the
`indirect_jump`, `jump`, `sibcall_insn` and `sibcall_value_insn`
patterns and we find it preferable to implement the functionality in the
same way for every pattern.
There is one particular case which is slightly tricky. The
implementation of TARGET_ASM_TRAMPOLINE_TEMPLATE uses a BR which needs
to be mitigated against. The trampoline template is used *once* per
compilation unit, and the TRAMPOLINE_SIZE is exposed to the user via the
builtin macro __LIBGCC_TRAMPOLINE_SIZE__.
In the future we may implement function specific attributes to turn on
and off hardening on a per-function basis.
The fixed nature of the trampoline described above implies it will be
safer to ensure this speculation barrier is always used.
Testing:
Bootstrap and regtest done on aarch64-none-linux
Used a temporary hack(1) to use these options on every test in the
testsuite and a script to check that the output never emitted an
unmitigated RET or BR.
1) Temporary hack was a change to the testsuite to always use
`-save-temps` and run a script on the assembly output of those
compilations which produced one to ensure every RET or BR is immediately
followed by a speculation barrier.
gcc/ChangeLog:
* config/aarch64/aarch64-protos.h (aarch64_sls_barrier): New.
* config/aarch64/aarch64.c (aarch64_output_casesi): Emit
speculation barrier after BR instruction if needs be.
(aarch64_trampoline_init): Handle ptr_mode value & adjust size
of code copied.
(aarch64_sls_barrier): New.
(aarch64_asm_trampoline_template): Add needed barriers.
* config/aarch64/aarch64.h (AARCH64_ISA_SB): New.
(TARGET_SB): New.
(TRAMPOLINE_SIZE): Account for barrier.
* config/aarch64/aarch64.md (indirect_jump, *casesi_dispatch,
simple_return, *do_return, *sibcall_insn, *sibcall_value_insn):
Emit barrier if needs be, also account for possible barrier using
"sls_length" attribute.
(sls_length): New attribute.
(length): Determine default using any non-default sls_length
value.
gcc/testsuite/ChangeLog:
* gcc.target/aarch64/sls-mitigation/sls-miti-retbr.c: New test.
* gcc.target/aarch64/sls-mitigation/sls-miti-retbr-pacret.c:
New test.
* gcc.target/aarch64/sls-mitigation/sls-mitigation.exp: New file.
* lib/target-supports.exp (check_effective_target_aarch64_asm_sb_ok):
New proc.
Here we introduce the flags that will be used for straight line speculation.
The new flag introduced is `-mharden-sls=`.
This flag can take arguments of `none`, `all`, or a comma seperated list of one
or more of `retbr` or `blr`.
`none` indicates no special mitigation of the straight line speculation
vulnerability.
`all` requests all mitigations currently implemented.
`retbr` requests that the RET and BR instructions have a speculation barrier
inserted after them.
`blr` requests that BLR instructions are replaced by a BL to a function stub
using a BR with a speculation barrier after it.
Setting this on a per-function basis using attributes or the like is not
enabled, but may be in the future.
gcc/ChangeLog:
2020-06-02 Matthew Malcomson <matthew.malcomson@arm.com>
* config/aarch64/aarch64-protos.h (aarch64_harden_sls_retbr_p):
New.
(aarch64_harden_sls_blr_p): New.
* config/aarch64/aarch64.c (enum aarch64_sls_hardening_type):
New.
(aarch64_harden_sls_retbr_p): New.
(aarch64_harden_sls_blr_p): New.
(aarch64_validate_sls_mitigation): New.
(aarch64_override_options): Parse options for SLS mitigation.
* config/aarch64/aarch64.opt (-mharden-sls): New option.
* doc/invoke.texi: Document new option.
This patch is derived from the review of vector with length patch
series. The length-based partial vector approach doesn't support
reduction so far, so we would like to disable vectorization with
partial vectors explicitly for it in vectorizable_condition.
Otherwise, it will cause some unexpected failures for a few cases
like gcc.dg/vect/pr65947-2.c.
But if we disable it for the cases excepting for reduction_type equal
to EXTRACT_LAST_REDUCTION, it cause one regression failure on aarch64:
gcc.target/aarch64/sve/reduc_8.c -march=armv8.2-a+sve
The disabling makes the outer loop can't work with partial vectors,
the check fails. But the case is safe to adopt it. As Richard S.
pointed out in the review comments, the extra inactive lanes only
matter for double reductions, so this patch is to permit vectorization
with partial vectors for cases EXTRACT_LAST_REDUCTION or nested-cycle
reduction.
Bootstrapped/regtested on aarch64-linux-gnu.
gcc/ChangeLog:
* tree-vect-stmts.c (vectorizable_condition): Prohibit vectorization
with partial vectors explicitly excepting for EXTRACT_LAST_REDUCTION
or nested-cycle reduction.
As Richard S. suggested in the review of vector with length patch
series, we can use one message on "partial vectors" instead of
"fully with masking". This patch is to update the dumping string
and related test cases.
Bootstrapped/regtested on aarch64-linux-gnu.
gcc/ChangeLog:
* tree-vect-loop.c (vect_analyze_loop_2): Update dumping string
for fully masking to be more common.
gcc/testsuite/ChangeLog:
* gcc.target/aarch64/sve/clastb_1.c: Update dumping string.
* gcc.target/aarch64/sve/clastb_2.c: Likewise.
* gcc.target/aarch64/sve/clastb_3.c: Likewise.
* gcc.target/aarch64/sve/clastb_4.c: Likewise.
* gcc.target/aarch64/sve/clastb_5.c: Likewise.
* gcc.target/aarch64/sve/clastb_6.c: Likewise.
* gcc.target/aarch64/sve/clastb_7.c: Likewise.
RISC-V has a dedicate register for thread pointer which is specified in psABI
doc, so we could support __builtin_thread_pointer in straightforward way.
Note: clang/llvm was supported __builtin_thread_pointer for RISC-V port
recently.
- https://reviews.llvm.org/rGaabc24acf0d5f8677bd22fe9c108581e07c3e180
gcc/ChangeLog:
* config/riscv/riscv.md (get_thread_pointer<mode>): New.
(TP_REGNUM): Ditto.
* doc/extend.texi (Target Builtins): Add RISC-V built-in section.
Document __builtin_thread_pointer.
gcc/testsuite/ChangeLog:
* gcc.target/riscv/read-thread-pointer.c: New.
- This optimization will adjust stack, but it not check/update other
stack pointer use-site, the example is when the arguments put on
stack, the offset become wrong after optimization.
- However adjust stack frame usage after register allocation could be
error prone, so we decide to turn off this optimization for such case.
- Ye-Ting Kuo report this issue on github:
https://github.com/riscv/riscv-gcc/pull/192
gcc/ChangeLog:
* config/riscv/riscv-sr.c (riscv_remove_unneeded_save_restore_calls):
Abort if any arguments on stack.
gcc/testsuite/ChangeLog
* gcc.target/riscv/save-restore-9.c: New.
This addresses the issue raised about the usage of memory copy functions
to toggle the scalar storage order. Recall that you cannot (the compiler
errors out) take the address of a scalar which is stored in reverse order,
but you can do it for the enclosing aggregate type., which means that you
can also pass it to the memory copy functions. In this case, the optimizer
may rewrite the copy into a scalar copy, which is a no-no.
gcc/c-family/ChangeLog:
* c.opt (Wscalar-storage-order): Add explicit variable.
gcc/c/ChangeLog:
* c-typeck.c (convert_for_assignment): If -Wscalar-storage-order is
set, warn for conversion between pointers that point to incompatible
scalar storage orders.
gcc/ChangeLog:
* gimple-fold.c (gimple_fold_builtin_memory_op): Do not fold if
either type has reverse scalar storage order.
* tree-ssa-sccvn.c (vn_reference_lookup_3): Do not propagate through
a memory copy if either type has reverse scalar storage order.
gcc/testsuite/ChangeLog:
* gcc.dg/sso-11.c: New test.
* gcc.dg/sso/sso.exp: Pass -Wno-scalar-storage-order.
* gcc.dg/sso/memcpy-1.c: New test.
We are ICEing in the testcase below because we pass the
yet-uninstantiated class type A<int> of the PARM_DECL b to
is_really_empty_class from is_rvalue_constant_expression when parsing
the requirement t += b.
This patch fixes the ICE by guarding the problematic call to
is_really_empty_class with a COMPLETE_TYPE_P check, which should also
subsume the existing dependent_type_p check.
gcc/cp/ChangeLog:
PR c++/95497
* constexpr.c (potential_constant_expression_1) <case PARM_DECL>:
When processing_template_decl, check COMPLETE_TYPE_P before
calling is_really_empty_class. Don't check dependent_type_p.
gcc/testsuite/ChangeLog:
PR c++/95497
* g++.dg/cpp2a/concepts-pr95497.C: New test.
gcc/ChangeLog:
2020-07-08 Will Schmidt <will_schmidt@vnet.ibm.com>
* config/rs6000/altivec.h (vec_vmsumudm): New define.
* config/rs6000/altivec.md (UNSPEC_VMSUMUDM): New unspec.
(altivec_vmsumudm): New define_insn.
* config/rs6000/rs6000-builtin.def (altivec_vmsumudm): New BU_ALTIVEC_3
entry. (vmsumudm): New BU_ALTIVEC_OVERLOAD_3 entry.
* config/rs6000/rs6000-call.c (altivec_overloaded_builtins): Add entries for
ALTIVEC_BUILTIN_VMSUMUDM variants of vec_msum.
* doc/extend.texi: Add document for vmsumudm behind vmsum.
gcc/testsuite/ChangeLog:
2020-07-08 Will Schmidt <will_schmidt@vnet.ibm.com>
* gcc.target/powerpc/builtins-msum-runnable.c: New test.
* gcc.target/powerpc/vsx-builtin-msum.c: New test.
This moves querying the alignment support scheme from load/store
transform time to get_load_store_type where we should know best
what alignment constraints we actually need. This should make
verify_data_ref_alignment obsolete which prematurely disqualifies
all vectorization IMHO.
2020-07-08 Richard Biener <rguenther@suse.de>
* tree-vect-stmts.c (get_group_load_store_type): Pass
in the SLP node and the alignment support scheme output.
Set that.
(get_load_store_type): Likewise.
(vectorizable_store): Adjust.
(vectorizable_load): Likewise.
gcc/ada/
* adaint.h (__gnat_expect_portable_execvp): Fix prototype.
(__gnat_expect_poll): Likewise.
* expect.c [_WIN32]: Include adaint.h file.
(__gnat_waitpid): Remove useless variable.
(__gnat_expect_portable_execvp): Add ATTRIBUTE_UNUSED on parameter.
* raise-gcc.c [SEH] (__gnat_personality_v0): Add ATTRIBUTE_UNUSED.
* socket.c [_WIN32] (__gnat_getservbyport): Add ATTRIBUTE_UNUSED on
a couple of parameters.
(__gnat_gethostbyname): Likewise.
(__gnat_gethostbyaddr): Likewise.
(__gnat_getservbyname): Likewise.
(__gnat_last_socket_in_set): Use variables local to loops.
(__gnat_socket_ioctl): Cast 3rd parameter to proper type if _WIN32.
(__gnat_inet_pton): Cast 2nd parameter to proper type if _WIN32.
* sysdep.c (__gnat_localtime_tzoff): Remove superfluous test.
* terminals.c [_WIN32]: Include io.h file.
(is_gui_app): Remove useless variables and fix unsigned comparison.
(nt_spawnve): Add ATTRIBUTE_UNUSED on first parameter. Initialize a
local variable and remove others that are useless. Add missing cast
(__gnat_setup_child_communication): Remove useless variable and call
Use proper formatting string in call to sprintf.
(__gnat_setup_parent_communication): Cast to proper type.
(find_child_console): Fix prototype and remove useless variable.
(find_process_handle): Likewise.
(_gnat_interrupt_process): Move to after __gnat_interrupt_pid.
(__gnat_reset_tty): Add ATTRIBUTE_UNUSED on parameter, remove return
(__gnat_setup_winsize): Add ATTRIBUTE_UNUSED on all parameters.
gcc/ada/
* exp_ch9.adb
(Build_Class_Wide_Master): Insert the declaration of _Master
before its use; required to avoid assertion failure in the
backend.
gcc/ada/
* libgnat/i-cexten.ads (long_long, unsigned_long_long): Now
subtypes of Interfaces.C types.
* libgnat/a-calcon.ads, libgnat/a-calcon.adb
(To_Unix_Nano_Time): Use Interfaces.C.long_long instead of
Interfaces.C.Extensions.long_long.
gcc/ada/
* debug.adb: Document new switch.
* exp_ch6.adb (Warn_BIP): New function that warns if the switch
is on. Call it from Make_Build_In_Place_* functions. Warn_BIP
is not needed in Make_Build_In_Place_Iface_*, because those call
Make_Build_In_Place_Call_In_Object_Declaration or similar.
gcc/ada/
* freeze.adb (Has_Decl_In_List): New predicate to check that an
entity is declared in a list of nodes.
(Freeze_Expression): Use it to deal with Expression_With_Actions,
short-circuit expression, if- and case-expression and ensure that
the freeze node is put onto their Actions list if the entity is
declared locally.
gcc/ada/
* sem_attr.adb (Analyze_Attribute): Correct prefix of 'Result
this prefix is a generic function but the enclosing aspect or
pragma is attached to its instance.
* sem_ch12.adb (Analyze_Generic_Subprogram_Declaration): Analyze
generic subprogram formal parameters (including the implicit
result of a generic function) and only then analyse its aspects,
because with Relaxed_Initialization the aspect expression might
refer to those formal parameters.
* sem_ch13.adb (Analyze_Aspect_Relaxed_Initialization): Accept
aspect on generic subprograms; install formal parameters of a
generic subprogram but not formal parameters of the generic unit
itself (the previous code was inspired by aspects Post and
Depends, where both kinds of formals are allowed).
* sem_util.ads (Enter_Name): Fix name of a subprogram referenced
in comment.
gcc/ada/
* sem_prag.adb (Process_Inline): Check for duplicate
pragma+aspect Inline. Minor code cleanup.
(Check_Duplicate_Pragma): Add warning for duplicate
pragma [No_]Inline under -gnatwr.
* sinfo.ads, sinfo.adb (Next_Rep_Item): Allow N_Null_Statement
which can appear when a pragma is rewritten.
* sem_util.ads, sem_util.adb, bindo-writers.adb: Fix bad
copy/paste now flagged.
* libgnat/s-mmap.ads: Remove redundant pragma Inline.
gcc/ada/
* sem_ch13.adb (Predicate_Failure): Check that the type has
predicates. Remove the setting of Has_Delayed_Aspects and
Freeze_Node, because (if the code is legal) it should have
already been done by the predicate aspect.
gcc/ada/
* par.adb (P_Iterator_Specification): Make public for use in
other parser subprograms.
* par-ch4.adb (P_Iterated_Component_Association): In Ada_2020,
recognize use of Iterator_Specification in an element iterator.
To simplify disambiguation between the two iterator forms, mark
the component association as carrying an Iterator_Specification
only when the element iterator (using "OF") is used.
* par-ch5.adb (P_Loop_Parameter_Specification): In Ada_2020,
parse iterator filter when present.
(P_Iterator_Specification): Ditto. Remove declaration of
P_Iterator_Specification, now in parent unit.
* exp_ch5.adb (Expand_N_Loop_Statement): Apply Iterator filter
when present.
(Expand_Iterator_Loop_Over_Array): Ditto.
(Expand_Iterator_Loop_Over_Container): Ditto.
* sem_aggr.adb (Resolve_Array_Aggregate): Emit error nessage if
an iterated component association includes a iterator
specificcation with an element iterator, i.e. one that uses the
OF keyword.
* sem_ch5.adb (Analyze_Iterator_Specification): Analyze Iterator
filter when present.
(Analyze_Loop_Parameter_Specification): Ditto.
* sinfo.adb: Suprogram bodies for new syntactic element
Iterator_Filter.
* sinfo.ads: Add Iterator_Filter to relevant nodes. Structure
of Component_Association and Iteroted_Component_Association
nodes is modified to take into account the possible presence of
an iterator specification in the latter.
gcc/ada/
* exp_attr.adb (Expand_Attribute): Set
Stores_Attribute_Old_Prefix to generated renamings of 'Old
constants for later use in generating finalization routines.
* exp_ch7.adb (Build_Finalizer): Minor reformatting. Use "or
else" operators.
gcc/ada/
* exp_ch6.adb (Expand_Simple_Function_Return): Remove ugly code
that was copying the return expression, resetting Analyzed
flags, etc. for the return expression of static expression
functions.
* inline.adb (Inline_Static_Expression_Function_Call): Set the
Parent of the copied expression to that of the call. This avoids
a blowup in Insert_Actions when GNATprove_Mode is set and there
are nested SEF calls. Add ??? comment.
* sem_ch6.adb (Analyze_Expression_Function): In the case of a
static expression function, create a new copy of the expression
and replace the function's expression with the copy; the
original expression is used in the expression function's body
and will be analyzed and rewritten, and we need to save a clean
copy for later use in processing static calls to the function.
This allows removing the kludgy code that was in
Expand_Simple_Function_Return.
* sem_eval.adb (Eval_Qualified_Expression): Return immediately
if any errors have been posted on the qualified expression, to
avoid blowups when GNATprove_Mode is enabled (or with -gnatd.F),
since illegal static expressions are handled differently in that
case and attempting to fold such expressions would fail.
gcc/ada/
* repinfo.adb (Compute_Max_Length): Skip hidden discriminants.
(List_Record_Layout): Likewise.
(List_Structural_Record_Layout): Use First_Discriminant instead
of First_Stored_Discriminant and Next_Discriminant instead of
Next_Stored_Discriminant to walk the list of discriminants.
gcc/ada/
* sem_ch13.adb (Analyze_Aspect_Specifications): Add freeze node
for the Underlying_Full_View if it exists. The freeze node is
what triggers the generation of the predicate function.
* freeze.adb: Minor reformatting.
