Only interesting thing here is that we have to make sure the tagging mechanism
is deterministic to avoid flaky tests.
gcc/testsuite/ChangeLog:
* c-c++-common/ubsan/sanitize-recover-7.c: Update error message format.
* lib/asan-dg.exp (asan_link_flags): Implement as a helper
function asan_link_flags_1 which asan_link_flags and
hwasan_link_flags use.
(asan_link_flags_1): Parametrised version of asan_link_flags.
* c-c++-common/hwasan/aligned-alloc.c: New test.
* c-c++-common/hwasan/alloca-array-accessible.c: New test.
* c-c++-common/hwasan/alloca-base-init.c: New test.
* c-c++-common/hwasan/alloca-gets-different-tag.c: New test.
* c-c++-common/hwasan/alloca-outside-caught.c: New test.
* c-c++-common/hwasan/arguments-1.c: New test.
* c-c++-common/hwasan/arguments-2.c: New test.
* c-c++-common/hwasan/arguments-3.c: New test.
* c-c++-common/hwasan/arguments.c: New test.
* c-c++-common/hwasan/asan-pr63316.c: New test.
* c-c++-common/hwasan/asan-pr70541.c: New test.
* c-c++-common/hwasan/asan-pr78106.c: New test.
* c-c++-common/hwasan/asan-pr79944.c: New test.
* c-c++-common/hwasan/asan-rlimit-mmap-test-1.c: New test.
* c-c++-common/hwasan/bitfield-1.c: New test.
* c-c++-common/hwasan/bitfield-2.c: New test.
* c-c++-common/hwasan/builtin-special-handling.c: New test.
* c-c++-common/hwasan/check-interface.c: New test.
* c-c++-common/hwasan/halt_on_error-1.c: New test.
* c-c++-common/hwasan/handles-poly_int-marked-vars.c: New test.
* c-c++-common/hwasan/heap-overflow.c: New test.
* c-c++-common/hwasan/hwasan-poison-optimisation.c: New test.
* c-c++-common/hwasan/hwasan-thread-access-parent.c: New test.
* c-c++-common/hwasan/hwasan-thread-basic-failure.c: New test.
* c-c++-common/hwasan/hwasan-thread-clears-stack.c: New test.
* c-c++-common/hwasan/hwasan-thread-success.c: New test.
* c-c++-common/hwasan/kernel-defaults.c: New test.
* c-c++-common/hwasan/large-aligned-0.c: New test.
* c-c++-common/hwasan/large-aligned-1.c: New test.
* c-c++-common/hwasan/large-aligned-untagging-0.c: New test.
* c-c++-common/hwasan/large-aligned-untagging-1.c: New test.
* c-c++-common/hwasan/large-aligned-untagging-2.c: New test.
* c-c++-common/hwasan/large-aligned-untagging-3.c: New test.
* c-c++-common/hwasan/large-aligned-untagging-4.c: New test.
* c-c++-common/hwasan/large-aligned-untagging-5.c: New test.
* c-c++-common/hwasan/large-aligned-untagging-6.c: New test.
* c-c++-common/hwasan/large-aligned-untagging-7.c: New test.
* c-c++-common/hwasan/macro-definition.c: New test.
* c-c++-common/hwasan/no-sanitize-attribute.c: New test.
* c-c++-common/hwasan/param-instrument-mem-intrinsics.c: New test.
* c-c++-common/hwasan/param-instrument-reads-and-writes.c: New test.
* c-c++-common/hwasan/param-instrument-reads.c: New test.
* c-c++-common/hwasan/param-instrument-writes.c: New test.
* c-c++-common/hwasan/random-frame-tag.c: New test.
* c-c++-common/hwasan/sanity-check-pure-c.c: New test.
* c-c++-common/hwasan/setjmp-longjmp-0.c: New test.
* c-c++-common/hwasan/setjmp-longjmp-1.c: New test.
* c-c++-common/hwasan/stack-tagging-basic-0.c: New test.
* c-c++-common/hwasan/stack-tagging-basic-1.c: New test.
* c-c++-common/hwasan/stack-tagging-disable.c: New test.
* c-c++-common/hwasan/unprotected-allocas-0.c: New test.
* c-c++-common/hwasan/unprotected-allocas-1.c: New test.
* c-c++-common/hwasan/use-after-free.c: New test.
* c-c++-common/hwasan/vararray-outside-caught.c: New test.
* c-c++-common/hwasan/vararray-stack-restore-correct.c: New test.
* c-c++-common/hwasan/very-large-objects.c: New test.
* g++.dg/hwasan/hwasan.exp: New test.
* g++.dg/hwasan/rvo-handled.C: New test.
* gcc.dg/hwasan/hwasan.exp: New test.
* gcc.dg/hwasan/nested-functions-0.c: New test.
* gcc.dg/hwasan/nested-functions-1.c: New test.
* gcc.dg/hwasan/nested-functions-2.c: New test.
* lib/hwasan-dg.exp: New file.
There are four main features to this change:
1) Check pointer tags match address tags.
When sanitizing for hwasan we now put HWASAN_CHECK internal functions before
memory accesses in the `asan` pass. This checks that a tag in the pointer
being used match the tag stored in shadow memory for the memory region being
used.
These internal functions are expanded into actual checks in the sanopt
pass that happens just before expansion into RTL.
We use the same mechanism that currently inserts ASAN_CHECK internal
functions to insert the new HWASAN_CHECK functions.
2) Instrument known builtin function calls.
Handle all builtin functions that we know use memory accesses.
This commit uses the machinery added for ASAN to identify builtin
functions that access memory.
The main differences between the approaches for HWASAN and ASAN are:
- libhwasan intercepts much less builtin functions.
- Alloca needs to be transformed differently (instead of adding
redzones it needs to tag shadow memory and return a tagged pointer).
- stack_restore needs to untag the shadow stack between the current
position and where it's going.
- `noreturn` functions can not be handled by simply unpoisoning the
entire shadow stack -- there is no "always valid" tag.
(exceptions and things such as longjmp need to be handled in a
different way, usually in the runtime).
For hardware implemented checking (such as AArch64's memory tagging
extension) alloca and stack_restore will need to be handled by hooks in
the backend rather than transformation at the gimple level. This will
allow architecture specific handling of such stack modifications.
3) Introduce HWASAN block-scope poisoning
Here we use exactly the same mechanism as ASAN_MARK to poison/unpoison
variables on entry/exit of a block.
In order to simply use the exact same machinery we're using the same
internal functions until the SANOPT pass. This means that all handling
of ASAN_MARK is the same.
This has the negative that the naming may be a little confusing, but a
positive that handling of the internal function doesn't have to be
duplicated for a function that behaves exactly the same but has a
different name.
gcc/ChangeLog:
* asan.c (asan_instrument_reads): New.
(asan_instrument_writes): New.
(asan_memintrin): New.
(handle_builtin_stack_restore): Account for HWASAN.
(handle_builtin_alloca): Account for HWASAN.
(get_mem_refs_of_builtin_call): Special case strlen for HWASAN.
(hwasan_instrument_reads): New.
(hwasan_instrument_writes): New.
(hwasan_memintrin): New.
(report_error_func): Assert not HWASAN.
(build_check_stmt): Make HWASAN_CHECK instead of ASAN_CHECK.
(instrument_derefs): HWASAN does not tag globals.
(instrument_builtin_call): Use new helper functions.
(maybe_instrument_call): Don't instrument `noreturn` functions.
(initialize_sanitizer_builtins): Add new type.
(asan_expand_mark_ifn): Account for HWASAN.
(asan_expand_check_ifn): Assert never called by HWASAN.
(asan_expand_poison_ifn): Account for HWASAN.
(asan_instrument): Branch based on whether using HWASAN or ASAN.
(pass_asan::gate): Return true if sanitizing HWASAN.
(pass_asan_O0::gate): Return true if sanitizing HWASAN.
(hwasan_check_func): New.
(hwasan_expand_check_ifn): New.
(hwasan_expand_mark_ifn): New.
(gate_hwasan): New.
* asan.h (hwasan_expand_check_ifn): New decl.
(hwasan_expand_mark_ifn): New decl.
(gate_hwasan): New decl.
(asan_intercepted_p): Always false for hwasan.
(asan_sanitize_use_after_scope): Account for HWASAN.
* builtin-types.def (BT_FN_PTR_CONST_PTR_UINT8): New.
* gimple-fold.c (gimple_build): New overload for building function
calls without arguments.
(gimple_build_round_up): New.
* gimple-fold.h (gimple_build): New decl.
(gimple_build): New inline function.
(gimple_build_round_up): New decl.
(gimple_build_round_up): New inline function.
* gimple-pretty-print.c (dump_gimple_call_args): Account for
HWASAN.
* gimplify.c (asan_poison_variable): Account for HWASAN.
(gimplify_function_tree): Remove requirement of
SANITIZE_ADDRESS, requiring asan or hwasan is accounted for in
`asan_sanitize_use_after_scope`.
* internal-fn.c (expand_HWASAN_CHECK): New.
(expand_HWASAN_ALLOCA_UNPOISON): New.
(expand_HWASAN_CHOOSE_TAG): New.
(expand_HWASAN_MARK): New.
(expand_HWASAN_SET_TAG): New.
* internal-fn.def (HWASAN_ALLOCA_UNPOISON): New.
(HWASAN_CHOOSE_TAG): New.
(HWASAN_CHECK): New.
(HWASAN_MARK): New.
(HWASAN_SET_TAG): New.
* sanitizer.def (BUILT_IN_HWASAN_LOAD1): New.
(BUILT_IN_HWASAN_LOAD2): New.
(BUILT_IN_HWASAN_LOAD4): New.
(BUILT_IN_HWASAN_LOAD8): New.
(BUILT_IN_HWASAN_LOAD16): New.
(BUILT_IN_HWASAN_LOADN): New.
(BUILT_IN_HWASAN_STORE1): New.
(BUILT_IN_HWASAN_STORE2): New.
(BUILT_IN_HWASAN_STORE4): New.
(BUILT_IN_HWASAN_STORE8): New.
(BUILT_IN_HWASAN_STORE16): New.
(BUILT_IN_HWASAN_STOREN): New.
(BUILT_IN_HWASAN_LOAD1_NOABORT): New.
(BUILT_IN_HWASAN_LOAD2_NOABORT): New.
(BUILT_IN_HWASAN_LOAD4_NOABORT): New.
(BUILT_IN_HWASAN_LOAD8_NOABORT): New.
(BUILT_IN_HWASAN_LOAD16_NOABORT): New.
(BUILT_IN_HWASAN_LOADN_NOABORT): New.
(BUILT_IN_HWASAN_STORE1_NOABORT): New.
(BUILT_IN_HWASAN_STORE2_NOABORT): New.
(BUILT_IN_HWASAN_STORE4_NOABORT): New.
(BUILT_IN_HWASAN_STORE8_NOABORT): New.
(BUILT_IN_HWASAN_STORE16_NOABORT): New.
(BUILT_IN_HWASAN_STOREN_NOABORT): New.
(BUILT_IN_HWASAN_TAG_MISMATCH4): New.
(BUILT_IN_HWASAN_HANDLE_LONGJMP): New.
(BUILT_IN_HWASAN_TAG_PTR): New.
* sanopt.c (sanopt_optimize_walker): Act for hwasan.
(pass_sanopt::execute): Act for hwasan.
* toplev.c (compile_file): Use `gate_hwasan` function.
Handling stack variables has three features.
1) Ensure HWASAN required alignment for stack variables
When tagging shadow memory, we need to ensure that each tag granule is
only used by one variable at a time.
This is done by ensuring that each tagged variable is aligned to the tag
granule representation size and also ensure that the end of each
object is aligned to ensure the start of any other data stored on the
stack is in a different granule.
This patch ensures the above by forcing the stack pointer to be aligned
before and after allocating any stack objects. Since we are forcing
alignment we also use `align_local_variable` to ensure this new alignment
is advertised properly through SET_DECL_ALIGN.
2) Put tags into each stack variable pointer
Make sure that every pointer to a stack variable includes a tag of some
sort on it.
The way tagging works is:
1) For every new stack frame, a random tag is generated.
2) A base register is formed from the stack pointer value and this
random tag.
3) References to stack variables are now formed with RTL describing an
offset from this base in both tag and value.
The random tag generation is handled by a backend hook. This hook
decides whether to introduce a random tag or use the stack background
based on the parameter hwasan-random-frame-tag. Using the stack
background is necessary for testing and bootstrap. It is necessary
during bootstrap to avoid breaking the `configure` test program for
determining stack direction.
Using the stack background means that every stack frame has the initial
tag of zero and variables are tagged with incrementing tags from 1,
which also makes debugging a bit easier.
Backend hooks define the size of a tag, the layout of the HWASAN shadow
memory, and handle emitting the code that inserts and extracts tags from a
pointer.
3) For each stack variable, tag and untag the shadow stack on function
prologue and epilogue.
On entry to each function we tag the relevant shadow stack region for
each stack variable. This stack region is tagged to match the tag added to
each pointer to that variable.
This is the first patch where we use the HWASAN shadow space, so we need
to add in the libhwasan initialisation code that creates this shadow
memory region into the binary we produce. This instrumentation is done
in `compile_file`.
When exiting a function we need to ensure the shadow stack for this
function has no remaining tags. Without clearing the shadow stack area
for this stack frame, later function calls could get false positives
when those later function calls check untagged areas (such as parameters
passed on the stack) against a shadow stack area with left-over tag.
Hence we ensure that the entire stack frame is cleared on function exit.
config/ChangeLog:
* bootstrap-hwasan.mk: Disable random frame tags for stack-tagging
during bootstrap.
gcc/ChangeLog:
* asan.c (struct hwasan_stack_var): New.
(hwasan_sanitize_p): New.
(hwasan_sanitize_stack_p): New.
(hwasan_sanitize_allocas_p): New.
(initialize_sanitizer_builtins): Define new builtins.
(ATTR_NOTHROW_LIST): New macro.
(hwasan_current_frame_tag): New.
(hwasan_frame_base): New.
(stack_vars_base_reg_p): New.
(hwasan_maybe_init_frame_base_init): New.
(hwasan_record_stack_var): New.
(hwasan_get_frame_extent): New.
(hwasan_increment_frame_tag): New.
(hwasan_record_frame_init): New.
(hwasan_emit_prologue): New.
(hwasan_emit_untag_frame): New.
(hwasan_finish_file): New.
(hwasan_truncate_to_tag_size): New.
* asan.h (hwasan_record_frame_init): New declaration.
(hwasan_record_stack_var): New declaration.
(hwasan_emit_prologue): New declaration.
(hwasan_emit_untag_frame): New declaration.
(hwasan_get_frame_extent): New declaration.
(hwasan_maybe_enit_frame_base_init): New declaration.
(hwasan_frame_base): New declaration.
(stack_vars_base_reg_p): New declaration.
(hwasan_current_frame_tag): New declaration.
(hwasan_increment_frame_tag): New declaration.
(hwasan_truncate_to_tag_size): New declaration.
(hwasan_finish_file): New declaration.
(hwasan_sanitize_p): New declaration.
(hwasan_sanitize_stack_p): New declaration.
(hwasan_sanitize_allocas_p): New declaration.
(HWASAN_TAG_SIZE): New macro.
(HWASAN_TAG_GRANULE_SIZE): New macro.
(HWASAN_STACK_BACKGROUND): New macro.
* builtin-types.def (BT_FN_VOID_PTR_UINT8_PTRMODE): New.
* builtins.def (DEF_SANITIZER_BUILTIN): Enable for HWASAN.
* cfgexpand.c (align_local_variable): When using hwasan ensure
alignment to tag granule.
(align_frame_offset): New.
(expand_one_stack_var_at): For hwasan use tag offset.
(expand_stack_vars): Record stack objects for hwasan.
(expand_one_stack_var_1): Record stack objects for hwasan.
(init_vars_expansion): Initialise hwasan state.
(expand_used_vars): Emit hwasan prologue and generate hwasan epilogue.
(pass_expand::execute): Emit hwasan base initialization if needed.
* doc/tm.texi (TARGET_MEMTAG_TAG_SIZE,TARGET_MEMTAG_GRANULE_SIZE,
TARGET_MEMTAG_INSERT_RANDOM_TAG,TARGET_MEMTAG_ADD_TAG,
TARGET_MEMTAG_SET_TAG,TARGET_MEMTAG_EXTRACT_TAG,
TARGET_MEMTAG_UNTAGGED_POINTER): Document new hooks.
* doc/tm.texi.in (TARGET_MEMTAG_TAG_SIZE,TARGET_MEMTAG_GRANULE_SIZE,
TARGET_MEMTAG_INSERT_RANDOM_TAG,TARGET_MEMTAG_ADD_TAG,
TARGET_MEMTAG_SET_TAG,TARGET_MEMTAG_EXTRACT_TAG,
TARGET_MEMTAG_UNTAGGED_POINTER): Document new hooks.
* explow.c (get_dynamic_stack_base): Take new `base` argument.
* explow.h (get_dynamic_stack_base): Take new `base` argument.
* sanitizer.def (BUILT_IN_HWASAN_INIT): New.
(BUILT_IN_HWASAN_TAG_MEM): New.
* target.def (target_memtag_tag_size,target_memtag_granule_size,
target_memtag_insert_random_tag,target_memtag_add_tag,
target_memtag_set_tag,target_memtag_extract_tag,
target_memtag_untagged_pointer): New hooks.
* targhooks.c (HWASAN_SHIFT): New.
(HWASAN_SHIFT_RTX): New.
(default_memtag_tag_size): New default hook.
(default_memtag_granule_size): New default hook.
(default_memtag_insert_random_tag): New default hook.
(default_memtag_add_tag): New default hook.
(default_memtag_set_tag): New default hook.
(default_memtag_extract_tag): New default hook.
(default_memtag_untagged_pointer): New default hook.
* targhooks.h (default_memtag_tag_size): New default hook.
(default_memtag_granule_size): New default hook.
(default_memtag_insert_random_tag): New default hook.
(default_memtag_add_tag): New default hook.
(default_memtag_set_tag): New default hook.
(default_memtag_extract_tag): New default hook.
(default_memtag_untagged_pointer): New default hook.
* toplev.c (compile_file): Call hwasan_finish_file when finished.
These flags can't be used at the same time as any of the other
sanitizers.
We add an equivalent flag to -static-libasan in -static-libhwasan to
ensure static linking.
The -fsanitize=kernel-hwaddress option is for compiling targeting the
kernel. This flag has defaults to match the LLVM implementation and
sets some other behaviors to work in the kernel (e.g. accounting for
the fact that the stack pointer will have 0xff in the top byte and to not
call the userspace library initialisation routines).
The defaults are that we do not sanitize variables on the stack and
always recover from a detected bug.
Since we are introducing a few more conflicts between sanitizer flags we
refactor the checking for such conflicts to use a helper function which
makes checking for such conflicts more easy and consistent.
We introduce a backend hook `targetm.memtag.can_tag_addresses` that
indicates to the mid-end whether a target has a feature like AArch64 TBI
where the top byte of an address is ignored.
Without this feature hwasan sanitization is not done.
gcc/ChangeLog:
* common.opt (flag_sanitize_recover): Default for kernel
hwaddress.
(static-libhwasan): New cli option.
* config/aarch64/aarch64.c (aarch64_can_tag_addresses): New.
(TARGET_MEMTAG_CAN_TAG_ADDRESSES): New.
* config/gnu-user.h (LIBHWASAN_EARLY_SPEC): hwasan equivalent of
asan command line flags.
* cppbuiltin.c (define_builtin_macros_for_compilation_flags):
Add hwasan equivalent of __SANITIZE_ADDRESS__.
* doc/invoke.texi: Document hwasan command line flags.
* doc/tm.texi: Document new hook.
* doc/tm.texi.in: Document new hook.
* flag-types.h (enum sanitize_code): New sanitizer values.
* gcc.c (STATIC_LIBHWASAN_LIBS): New macro.
(LIBHWASAN_SPEC): New macro.
(LIBHWASAN_EARLY_SPEC): New macro.
(SANITIZER_EARLY_SPEC): Update to include hwasan.
(SANITIZER_SPEC): Update to include hwasan.
(sanitize_spec_function): Use hwasan options.
* opts.c (finish_options): Describe conflicts between address
sanitizers.
(find_sanitizer_argument): New.
(report_conflicting_sanitizer_options): New.
(sanitizer_opts): Introduce new sanitizer flags.
(common_handle_option): Add defaults for kernel sanitizer.
* params.opt (hwasan--instrument-stack): New
(hwasan-random-frame-tag): New
(hwasan-instrument-allocas): New
(hwasan-instrument-reads): New
(hwasan-instrument-writes): New
(hwasan-instrument-mem-intrinsics): New
* target.def (HOOK_PREFIX): Add new hook.
(can_tag_addresses): Add new hook under memtag prefix.
* targhooks.c (default_memtag_can_tag_addresses): New.
* targhooks.h (default_memtag_can_tag_addresses): New decl.
* toplev.c (process_options): Ensure hwasan only on
architectures that advertise the possibility.
This is an analogous option to --bootstrap-asan to configure. It allows
bootstrapping GCC using HWASAN.
For the same reasons as for ASAN we have to avoid using the HWASAN
sanitizer when compiling libiberty and the lto-plugin.
Also add a function to query whether -fsanitize=hwaddress has been
passed.
ChangeLog:
* configure: Regenerate.
* configure.ac: Add --bootstrap-hwasan option.
config/ChangeLog:
* bootstrap-hwasan.mk: New file.
gcc/ChangeLog:
* doc/install.texi: Document new option.
libiberty/ChangeLog:
* configure: Regenerate.
* configure.ac: Avoid using sanitizer.
lto-plugin/ChangeLog:
* Makefile.am: Avoid using sanitizer.
* Makefile.in: Regenerate.
Though the library has limited support for x86, we don't have any
support for generating code targeting x86 so there is no point building
for that target.
Ensure we build for AArch64 but not for AArch64 ilp32.
libsanitizer/ChangeLog:
* Makefile.am: Condition Build hwasan directory.
* Makefile.in: Regenerate.
* configure: Regenerate.
* configure.ac: Set HWASAN_SUPPORTED based on target
architecture.
* configure.tgt: Likewise.
This patch tries to tie libhwasan into the GCC build system in the same way
that the other sanitizer runtime libraries are handled.
libsanitizer/ChangeLog:
* Makefile.am: Build libhwasan.
* Makefile.in: Build libhwasan.
* asan/Makefile.in: Build libhwasan.
* configure: Build libhwasan.
* configure.ac: Build libhwasan.
* hwasan/Makefile.am: New file.
* hwasan/Makefile.in: New file.
* hwasan/libtool-version: New file.
* interception/Makefile.in: Build libhwasan.
* libbacktrace/Makefile.in: Build libhwasan.
* libsanitizer.spec.in: Build libhwasan.
* lsan/Makefile.in: Build libhwasan.
* sanitizer_common/Makefile.in: Build libhwasan.
* tsan/Makefile.in: Build libhwasan.
* ubsan/Makefile.in: Build libhwasan.
In `GetGlobalSizeFromDescriptor` we use `dladdr` to get info on the the
current address. `dladdr` returns 0 if it failed.
During testing on Linux this returned 0 to indicate failure, and
populated the `info` structure with a NULL pointer which was
dereferenced later.
This patch checks for `dladdr` returning 0, and in that case returns 0
from `GetGlobalSizeFromDescriptor` to indicate failure of identifying
the address.
This occurs when `GetModuleNameAndOffsetForPC` succeeds for some address
not in a dynamically loaded library. One example is when the found
"module" is '[stack]' having come from parsing /proc/self/maps.
Cherry-pick from 83ac18205ec69a00ac2be3b603bc3a61293fbe89.
Differential Revision: https://reviews.llvm.org/D91344
In the conversion of a constant integer to a string type, the value of
the constant integer was being silently truncated from unsigned long
to unsigned int, producing the wrong string value. Add an explicit
overflow check to avoid this problem.
For golang/go#42790
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/272611
The following patch adds some improvements for __builtin_mul_overflow
expansion.
One optimization is for the u1 * u2 -> sr case, as documented we normally
do:
u1 * u2 -> sr
res = (S) (u1 * u2)
ovf = res < 0 || main_ovf (true)
where main_ovf (true) stands for jump on unsigned multiplication overflow.
If we know that the most significant bits of both operands are clear (such
as when they are zero extended from something smaller), we can
emit better coe by handling it like s1 * s2 -> sr, i.e. just jump on
overflow after signed multiplication.
Another two cases are s1 * s2 -> ur or s1 * u2 -> ur, if we know the minimum
precision needed to encode all values of both arguments summed together
is smaller or equal to destination precision (such as when the two arguments
are sign (or zero) extended from half precision types, we know the overflows
happen only iff one argument is negative and the other argument is positive
(not zero), because even if both have maximum possible values, the maximum
is still representable (e.g. for char * char -> unsigned short
0x7f * 0x7f = 0x3f01 and for char * unsigned char -> unsigned short
0x7f * 0xffU = 0x7e81) and as the result is unsigned, all negative results
do overflow, but are also representable if we consider the result signed
- all of them have the MSB set. So, it is more efficient to just
do the normal multiplication in that case and compare the result considered
as signed value against 0, if it is smaller, overflow happened.
And the get_min_precision change is to improve the char to short handling,
we have there in the IL
_2 = (int) arg_1(D);
promotion from C promotions from char or unsigned char arg, and the caller
adds a NOP_EXPR cast to short or unsigned short. get_min_precision punts
on the narrowing cast though, it handled only widening casts, but we can
handle narrowing casts fine too, by recursing on the narrowing cast operands
and using it only if it has in the end smaller minimal precision, which
would duplicate the sign bits (or zero bits) to both the bits above the
narrowing conversion and also at least one below that.
2020-10-25 Jakub Jelinek <jakub@redhat.com>
PR rtl-optimization/95862
* internal-fn.c (get_min_precision): For narrowing conversion, recurse
on the operand and if the operand precision is smaller than the
current one, return that smaller precision.
(expand_mul_overflow): For s1 * u2 -> ur and s1 * s2 -> ur cases
if the sum of minimum precisions of both operands is smaller or equal
to the result precision, just perform normal multiplication and
set overflow to the sign bit of the multiplication result. For
u1 * u2 -> sr if both arguments have the MSB known zero, use
normal s1 * s2 -> sr expansion.
* gcc.dg/builtin-artih-overflow-5.c: New test.
* cfg.c (free_block): New function.
(clear_edges): Rename to ....
(free_cfg): ... this one; also free BBs and vectors.
(expunge_block): Update comment.
* cfg.h (clear_edges): Rename to ...
(free_cfg): ... this one.
* cgraph.c (release_function_body): Use free_cfg.
This makes sure to lower VECTOR_BOOLEAN_TYPE_P typed non-vector
mode VEC_COND_EXPRs so we don't try to use vcond to expand those.
That's required for x86 and gcn integer mode boolean vectors.
2020-11-25 Richard Biener <rguenther@suse.de>
PR middle-end/97579
* gimple-isel.cc (gimple_expand_vec_cond_expr): Lower
VECTOR_BOOLEAN_TYPE_P, non-vector mode VEC_COND_EXPRs.
* gcc.dg/pr97579.c: New testcase.
The testcase had invalid assumptions about which loop iterations would run
first and last.
libgomp/ChangeLog
* testsuite/libgomp.oacc-fortran/atomic_capture-1.f90 (main): Adjust
expected results.
gcc/ada/
* freeze.adb (Is_Uninitialized_Aggregate): Move...
* exp_util.adb (Is_Uninitialized_Aggregate): ... here.
(Expand_Subtype_From_Expr): If the expression is an
uninitialized aggregate, capture subtype for declared object and
remove expression to suppress further superfluous expansion.
gcc/ada/
* sem_eval.adb (Subtypes_Statically_Compatible): Scalar types
with compatible static bounds are statically compatible if
predicates are compatible, even if they are not static subtypes.
Same for private types without discriminants.
gcc/ada/
* exp_ch11.adb (Expand_N_Raise_Statement): Use Is_Entity_Name
consistently in tests on the name of the statement.
* exp_prag.adb (Expand_Pragma_Check): In the local propagation
case, wrap the raise statement in a block statement.
gcc/ada/
* exp_ch8.adb (Expand_N_Exception_Renaming_Declaration): Move
"Nam" constant after the body of a nested subprogram; change "T"
from variable to constant.
gcc/ada/
* doc/gnat_rm/implementation_defined_attributes.rst
(Has_Tagged_Values): Document based on the existing description
of Has_Access_Type and the comment for Has_Tagged_Component,
which is where frontend evaluates this attribute.
* gnat_rm.texi: Regenerate.
* sem_attr.adb (Analyze_Attribute): Merge processing of
Has_Access_Type and Has_Tagged_Component attributes.
* sem_util.adb (Has_Access_Type): Fix casing in comment.
* sem_util.ads (Has_Tagged_Component): Remove wrong (or
outdated) comment about the use of this routine to implement the
equality operator.
gcc/ada/
* sem_ch13.adb (Analyze_One_Aspect): Detect aspect identifiers
with membership tests.
(Check_Aspect_At_End_Of_Declarations): Likewise.
(Freeze_Entity_Checks): Likewise; a local constant is no longer
needed.
(Is_Operational_Item): Similar simplification for attribute
identifiers.
(Is_Type_Related_Rep_Item): Likewise.
(Resolve_Iterable_Operation): Detect names with a membership
test.
(Validate_Independence): Replace repeated Ekind with a
membership test.
gcc/ada/
* exp_ch2.adb (Expand_Entity_Reference): A new local predicate
Is_Object_Renaming_Name indicates whether a given expression
occurs (after looking through qualified expressions and type
conversions) as the name of an object renaming declaration. If
Current_Value is available but this new predicate is True, then
ignore the availability of Current_Value.
gcc/ada/
* doc/gnat_rm/intrinsic_subprograms.rst (Shifts and Rotates):
Document behavior on negative numbers
* gnat_rm.texi: Regenerate.
* sem_eval.adb (Fold_Shift): Set modulus to be based on the RM
size for non-modular integer types.
gcc/ada/
* exp_util.adb (Remove_Side_Effects): Only remove side-effects
in GNATprove mode when this is useful.
* sem_res.adb (Set_Slice_Subtype): Make sure in GNATprove mode
to define the Itype when needed, so that run-time errors can be
analyzed.
* sem_util.adb (Enclosing_Declaration): Correctly take into
account renaming declarations.
gcc/ada/
* libgnat/g-rannum.ads (Random): New functions returning 128-bit.
* libgnat/g-rannum.adb (Random): Implement them and alphabetize.
(To_Signed): New unchecked conversion function for 128-bit.
gcc/ada/
* exp_util.adb (Attribute_Constrained_Static_Value): Fix body
box.
* sem_attr.adb (Eval_Attribute): Replace repeated calls to
Attribute_Name with a captured value of the Attribute_Id; also,
remove extra parens around Is_Generic_Type.
gcc/ada/
* exp_attr.adb (Expand_N_Attribute_Reference): A variable that
is only incremented in the code has now type Nat; conversion is
now unnecessary.
A while back I submitted GCC10 commit:
44f77a6dea2f312ee1743f3dde465c1b8453ee13
for PR91816.
Turns out I was an idiot and forgot to include the test in the actual git commit.
Tested that the test still passes on a cross arm-none-eabi and also in a
Cortex A-15 bootstrap with no regressions.
gcc/testsuite/ChangeLog:
PR target/91816
* gcc.target/arm/pr91816.c: New test.
libstdc++-v3/ChangeLog:
PR libstdc++/97936
* include/bits/atomic_wait.h (__platform_wait): Check errno,
not just the value of EAGAIN.
(__waiters::__waiters()): Fix name of data member.
The __platform_wait function is supposed to wait until *addr != old.
The futex syscall checks the initial value and returns EAGAIN if *addr
!= old is already true, which should cause __platform_wait to return.
Instead it loops and keeps doing a futex wait, which keeps returning
EAGAIN.
libstdc++-v3/ChangeLog:
PR libstdc++/97936
* include/bits/atomic_wait.h (__platform_wait): Return if futex
sets EAGAIN.
* testsuite/30_threads/latch/3.cc: Re-enable test.
* testsuite/30_threads/semaphore/try_acquire_until.cc: Likewise.
As mentioned in the PR, we currently ICE on flexible array members in
structs and unions during __builtin_clear_padding processing.
Jason said in the PR he'd prefer an error in these cases over forcefully
handling it as [0] arrays (everything is padding then) or consider the
arrays to have as many whole elements as would fit into the tail padding.
So, this patch implements that.
2020-11-25 Jakub Jelinek <jakub@redhat.com>
PR middle-end/97943
* gimple-fold.c (clear_padding_union, clear_padding_type): Error on and
ignore flexible array member fields. Ignore fields with
error_mark_node type.
* c-c++-common/builtin-clear-padding-2.c: New test.
* c-c++-common/builtin-clear-padding-3.c: New test.
* g++.dg/ext/builtin-clear-padding-1.C: New test.
* gcc.dg/builtin-clear-padding-2.c: New test.
