For /arch:AVX512F:
clang-cl and cl.exe both defines __AVX512F__ __AVX512CD__.
clang-cl also defines __AVX512ER__ __AVX512PF__.
64-bit cl.exe also defines (according to /Bz) _NO_PREFETCHW.
For /arch:AVX512:
clang-cl and cl.exe both define
__AVX512F__ __AVX512CD__ __AVX512BW__ __AVX512DQ__ __AVX512VL__.
64-bit cl.exe also defines _NO_PREFETCHW.
So not 100% identical, but pretty close.
Also refactor the existing AVX / AVX2 code to not repeat itself in both the
32-bit and 64-bit cases.
https://reviews.llvm.org/D42538
llvm-svn: 323433
r213083 initially implemented /arch: support by mapping it to CPU features.
Then r241077 additionally mapped it to CPU, which made the feature flags
redundant (if harmless). This change here removes the redundant mapping to
feature flags, and rewrites test/Driver/cl-x86-flags.c to be a bit more of an
integration test that checks for preprocessor defines like AVX (like documented
on MSDN) instead of for driver flags.
To keep emitting warn_drv_unused_argument, use getLastArgNoClaim() followed by an explicit claim() if needed.
This is in preparation for adding support for /arch:AVX512(F).
No intended behavior change.
https://reviews.llvm.org/D42497
llvm-svn: 323426
Summary:
Consider the text proto:
```
message {
sub { key: value }
}
```
Previously the first `{` was TT_Unknown, which caused the inner message to be
indented by the continuation width. This didn't happen for:
```
message {
sub: { key: value }
}
```
This is because the code to mark the first `{` as a TT_DictLiteral was only
considering the case where it marches forward and reaches a `:`.
This patch updates this by looking not only for `:`, but also for `<` and `{`.
Reviewers: djasper
Reviewed By: djasper
Subscribers: klimek, cfe-commits
Differential Revision: https://reviews.llvm.org/D42500
llvm-svn: 323419
r317337 missed that scudo is supported on MIPS32, so permit that option for
MIPS32.
Reviewers: cryptoad, atanasyan
Differential Revision: https://reviews.llvm.org/D42416
llvm-svn: 323412
Do not attempt to get the pointee of void* while generating a bug report
(otherwise it will trigger an assert inside RegionStoreManager::getBinding
assert(!T->isVoidType() && "Attempting to dereference a void pointer!")).
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D42396
llvm-svn: 323382
Summary:
Use corutine function arguments to initialize a promise type, but only
if the promise type defines a constructor that takes those arguments.
Otherwise, fall back to the default constructor.
Test Plan: check-clang
Reviewers: rsmith, GorNishanov, eric_niebler
Reviewed By: GorNishanov
Subscribers: toby-allsopp, lewissbaker, EricWF, cfe-commits
Differential Revision: https://reviews.llvm.org/D41820
llvm-svn: 323381
This allows the analyzer to analyze ("inline") custom operator new() calls and,
even more importantly, inline constructors of objects that were allocated
by any operator new() - not necessarily a custom one.
All changes in the tests in the current commit are intended improvements,
even if they didn't carry any explicit FIXME flag.
It is possible to restore the old behavior via
-analyzer-config c++-allocator-inlining=false
(this flag is supported by scan-build as well, and it can be into a clang
--analyze invocation via -Xclang .. -Xclang ..). There is no intention to
remove the old behavior for now.
Differential Revision: https://reviews.llvm.org/D42219
rdar://problem/12180598
llvm-svn: 323373
I.e. not after. In the c++-allocator-inlining=true mode, we need to make the
assumption that the conservatively evaluated operator new() has returned a
non-null value. Previously we did this on CXXNewExpr, but now we have to do that
before calling the constructor, because some clever constructors are sometimes
assuming that their "this" is null and doing weird stuff. We would also crash
upon evaluating CXXNewExpr when the allocator was inlined and returned null and
had a throw specification; this is UB even for custom allocators, but we still
need not to crash.
Added more FIXME tests to ensure that eventually we fix calling the constructor
for null return values.
Differential Revision: https://reviews.llvm.org/D42192
llvm-svn: 323370
The MSVC runtime library does not provide a definition of wmemcmp,
so we need an inline implementation.
Differential Revision: https://reviews.llvm.org/D42441
llvm-svn: 323362
Hidden visibility is almost the opposite of dllimport. We were
producing them before (dllimport wins in the existing llvm
implementation), but now the llvm verifier produces an error.
llvm-svn: 323361
NVPTX does not have runtime support necessary for profiling to work
and even call arc collection is prohibitively expensive. Furthermore,
there's no easy way to collect the samples. NVPTX also does not
support global constructors that clang generates if sample/arc collection
is enabled.
Differential Revision: https://reviews.llvm.org/D42452
llvm-svn: 323345
Summary:
Commonly string literals in protos are already multiline, so breaking them
further is undesirable.
Reviewers: djasper
Reviewed By: djasper
Subscribers: klimek, cfe-commits
Differential Revision: https://reviews.llvm.org/D42373
llvm-svn: 323319
This is to fix the bug reported in https://bugs.llvm.org/show_bug.cgi?id=34347#c6.
Currently, all MaxAtomicInlineWidth of x86-32 targets are set to 64. However,
i386 doesn't support any cmpxchg related instructions. i486 only supports cmpxchg.
So in this patch MaxAtomicInlineWidth is reset as follows:
For i386, the MaxAtomicInlineWidth should be 0 because no cmpxchg is supported.
For i486, the MaxAtomicInlineWidth should be 32 because it supports cmpxchg.
For others 32 bits x86 cpu, the MaxAtomicInlineWidth should be 64 because of cmpxchg8b.
Differential Revision: https://reviews.llvm.org/D42154
llvm-svn: 323281
We would previously treat `SEL` as a pointer-only type. This is not the
case. It should be treated similarly to `id` and `Class`. Add some
test cases to ensure that it will be properly handled as well.
llvm-svn: 323257
These symbols are supposed to be preserved even by the linker. Use the
`llvm.used` to ensure that the symbols are not removed by DCE in the
linker. This should be a no-op change on MachO since the symbols are
annotated as `no_dead_strip`.
llvm-svn: 323247
Analyzing problems which appear in scan-build results can be very
difficult, as after the launch no exact invocation is stored, and it's
super-hard to launch the debugger.
With this patch, the exact analyzer invocation appears in the footer,
and can be copied to debug/check reproducibility/etc.
rdar://35980230
llvm-svn: 323245
Rather than hardcode the pointerness of the `id` and `class` types,
handle them generically. This allows for the template type
specialization of `remove_pointer<id>` which would look through the `id`
type and deal with the `objc_object` structure without the pointer.
llvm-svn: 323241
We should (almost) never consider a device-side declaration to match a
library builtin functio. Otherwise clang may ignore the implementation
provided by the CUDA headers and emit clang's idea of the builtin.
Differential Revision: https://reviews.llvm.org/D42319
llvm-svn: 323239
Summary:
The parameter overrides the underlying vfs used by ClangTool for
filesystem operations.
Patch by Vladimir Plyashkun.
Reviewers: alexfh, ilya-biryukov
Reviewed By: ilya-biryukov
Subscribers: klimek, cfe-commits
Differential Revision: https://reviews.llvm.org/D41947
llvm-svn: 323195
Summary:
This patch is meant to address the last outstanding review comment on the already approved
(but not yet commited) https://reviews.llvm.org/D35755, namely making the handling of the RHEL
devtoolsets Linux-specific.
Don't know if it's best integrated into the former or applied subsequently.
Tested on i386-pc-solaris2.11 and x86_64-pc-linux-gnu.
Reviewers: fedor.sergeev, tstellar, jyknight
Reviewed By: fedor.sergeev
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D42029
llvm-svn: 323194
Summary:
General idea is to utilize generic (mostly Generic_GCC) code
and get rid of Solaris-specific handling as much as possible.
In particular:
- scanLibDirForGCCTripleSolaris was removed, relying on generic
CollectLibDirsAndTriples
- findBiarchMultilibs is now properly utilized to switch between
m32 and m64 include & lib paths on Solaris
- C system include handling copied from Linux (bar multilib hacks)
Fixes PR24606.
Reviewers: dlj, rafael, jyknight, theraven, tstellar
Reviewed By: jyknight
Subscribers: aaron.ballman, mgorny, krytarowski, ro, joerg, cfe-commits
Differential Revision: https://reviews.llvm.org/D35755
llvm-svn: 323193
Summary:
This patch fixes an issue where the UnbreakableTailLength would be counted towards
the length of a token during breaking, even though we can break after the token.
For example, this proto text with column limit 20
```
# ColumnLimit: 20 V
foo: {
bar: {
bazoo: "aaaaaaa"
}
}
```
was broken:
```
# ColumnLimit: 20 V
foo: {
bar: {
bazoo:
"aaaaaaa"
}
}
```
because the 2 closing `}` were counted towards the string literal's `UnbreakableTailLength`.
Reviewers: djasper
Reviewed By: djasper
Subscribers: klimek, cfe-commits
Differential Revision: https://reviews.llvm.org/D42376
llvm-svn: 323188
Pass and return _Float16 as if it were an int or float for ARM, but with the
top 16 bits unspecified, similarly like we already do for __fp16.
We will implement proper half-precision function argument lowering in the ARM
backend soon, but want to use this workaround in the mean time.
Differential Revision: https://reviews.llvm.org/D42318
llvm-svn: 323185
When a function taking transparent union is declared as taking one of
union members earlier in the translation unit, clang would hit an
"Invalid cast" assertion during EmitFunctionProlog. This case
corresponds to function f1 in test/CodeGen/transparent-union-redecl.c.
We decided to cast i32 to union because after merging function
declarations function parameter type becomes int,
CGFunctionInfo::ArgInfo type matches with ABIArgInfo type, so we decide
it is a trivial case. But these types should also be castable to
parameter declaration type which is not the case here.
Now the fix is in converting from ABIArgInfo type to VarDecl type and using
argument demotion when necessary.
Additional tests in Sema/transparent-union.c capture current behavior and make
sure there are no regressions.
rdar://problem/34949329
Reviewers: rjmccall, rafael
Reviewed By: rjmccall
Subscribers: aemerson, cfe-commits, kristof.beyls, ahatanak
Differential Revision: https://reviews.llvm.org/D41311
llvm-svn: 323156
Summary:
First, we need to explain the core of the vulnerability. Note that this
is a very incomplete description, please see the Project Zero blog post
for details:
https://googleprojectzero.blogspot.com/2018/01/reading-privileged-memory-with-side.html
The basis for branch target injection is to direct speculative execution
of the processor to some "gadget" of executable code by poisoning the
prediction of indirect branches with the address of that gadget. The
gadget in turn contains an operation that provides a side channel for
reading data. Most commonly, this will look like a load of secret data
followed by a branch on the loaded value and then a load of some
predictable cache line. The attacker then uses timing of the processors
cache to determine which direction the branch took *in the speculative
execution*, and in turn what one bit of the loaded value was. Due to the
nature of these timing side channels and the branch predictor on Intel
processors, this allows an attacker to leak data only accessible to
a privileged domain (like the kernel) back into an unprivileged domain.
The goal is simple: avoid generating code which contains an indirect
branch that could have its prediction poisoned by an attacker. In many
cases, the compiler can simply use directed conditional branches and
a small search tree. LLVM already has support for lowering switches in
this way and the first step of this patch is to disable jump-table
lowering of switches and introduce a pass to rewrite explicit indirectbr
sequences into a switch over integers.
However, there is no fully general alternative to indirect calls. We
introduce a new construct we call a "retpoline" to implement indirect
calls in a non-speculatable way. It can be thought of loosely as
a trampoline for indirect calls which uses the RET instruction on x86.
Further, we arrange for a specific call->ret sequence which ensures the
processor predicts the return to go to a controlled, known location. The
retpoline then "smashes" the return address pushed onto the stack by the
call with the desired target of the original indirect call. The result
is a predicted return to the next instruction after a call (which can be
used to trap speculative execution within an infinite loop) and an
actual indirect branch to an arbitrary address.
On 64-bit x86 ABIs, this is especially easily done in the compiler by
using a guaranteed scratch register to pass the target into this device.
For 32-bit ABIs there isn't a guaranteed scratch register and so several
different retpoline variants are introduced to use a scratch register if
one is available in the calling convention and to otherwise use direct
stack push/pop sequences to pass the target address.
This "retpoline" mitigation is fully described in the following blog
post: https://support.google.com/faqs/answer/7625886
We also support a target feature that disables emission of the retpoline
thunk by the compiler to allow for custom thunks if users want them.
These are particularly useful in environments like kernels that
routinely do hot-patching on boot and want to hot-patch their thunk to
different code sequences. They can write this custom thunk and use
`-mretpoline-external-thunk` *in addition* to `-mretpoline`. In this
case, on x86-64 thu thunk names must be:
```
__llvm_external_retpoline_r11
```
or on 32-bit:
```
__llvm_external_retpoline_eax
__llvm_external_retpoline_ecx
__llvm_external_retpoline_edx
__llvm_external_retpoline_push
```
And the target of the retpoline is passed in the named register, or in
the case of the `push` suffix on the top of the stack via a `pushl`
instruction.
There is one other important source of indirect branches in x86 ELF
binaries: the PLT. These patches also include support for LLD to
generate PLT entries that perform a retpoline-style indirection.
The only other indirect branches remaining that we are aware of are from
precompiled runtimes (such as crt0.o and similar). The ones we have
found are not really attackable, and so we have not focused on them
here, but eventually these runtimes should also be replicated for
retpoline-ed configurations for completeness.
For kernels or other freestanding or fully static executables, the
compiler switch `-mretpoline` is sufficient to fully mitigate this
particular attack. For dynamic executables, you must compile *all*
libraries with `-mretpoline` and additionally link the dynamic
executable and all shared libraries with LLD and pass `-z retpolineplt`
(or use similar functionality from some other linker). We strongly
recommend also using `-z now` as non-lazy binding allows the
retpoline-mitigated PLT to be substantially smaller.
When manually apply similar transformations to `-mretpoline` to the
Linux kernel we observed very small performance hits to applications
running typical workloads, and relatively minor hits (approximately 2%)
even for extremely syscall-heavy applications. This is largely due to
the small number of indirect branches that occur in performance
sensitive paths of the kernel.
When using these patches on statically linked applications, especially
C++ applications, you should expect to see a much more dramatic
performance hit. For microbenchmarks that are switch, indirect-, or
virtual-call heavy we have seen overheads ranging from 10% to 50%.
However, real-world workloads exhibit substantially lower performance
impact. Notably, techniques such as PGO and ThinLTO dramatically reduce
the impact of hot indirect calls (by speculatively promoting them to
direct calls) and allow optimized search trees to be used to lower
switches. If you need to deploy these techniques in C++ applications, we
*strongly* recommend that you ensure all hot call targets are statically
linked (avoiding PLT indirection) and use both PGO and ThinLTO. Well
tuned servers using all of these techniques saw 5% - 10% overhead from
the use of retpoline.
We will add detailed documentation covering these components in
subsequent patches, but wanted to make the core functionality available
as soon as possible. Happy for more code review, but we'd really like to
get these patches landed and backported ASAP for obvious reasons. We're
planning to backport this to both 6.0 and 5.0 release streams and get
a 5.0 release with just this cherry picked ASAP for distros and vendors.
This patch is the work of a number of people over the past month: Eric, Reid,
Rui, and myself. I'm mailing it out as a single commit due to the time
sensitive nature of landing this and the need to backport it. Huge thanks to
everyone who helped out here, and everyone at Intel who helped out in
discussions about how to craft this. Also, credit goes to Paul Turner (at
Google, but not an LLVM contributor) for much of the underlying retpoline
design.
Reviewers: echristo, rnk, ruiu, craig.topper, DavidKreitzer
Subscribers: sanjoy, emaste, mcrosier, mgorny, mehdi_amini, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D41723
llvm-svn: 323155
The check (inside StackHintGeneratorForSymbol::getMessage)
if (!N)
return getMessageForSymbolNotFound()
is moved to the beginning of the function.
Differential revision: https://reviews.llvm.org/D42388
Test plan: make check-all
llvm-svn: 323146
Summary:
This patch removes IdentifierInfo from completion token after remembering
the identifier in the preprocessor.
Prior to this patch, completion token had the IdentifierInfo set to null when
completing at the start of identifier and to the II for completion prefix
when in the middle of identifier.
This patch unifies how code completion token is handled when it is insterted
before the identifier and in the middle of the identifier.
The actual IdentifierInfo can still be obtained from the Preprocessor.
Reviewers: bkramer, arphaman
Reviewed By: bkramer
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D42241
llvm-svn: 323133
Summary:
The MultiplexExternalSemaSource doesn't correctly overload the `getModule` function,
causing the multiplexer to not forward this call as intended.
Reviewers: v.g.vassilev
Reviewed By: v.g.vassilev
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D39416
llvm-svn: 323122
Saleem Abdulrasool