register destructor functions annotated with __attribute__((destructor))
using __cxa_atexit or atexit.
Register destructor functions annotated with __attribute__((destructor))
calling __cxa_atexit in a synthesized constructor function instead of
emitting references to the functions in a special section.
The primary reason for adding this option is that we are planning to
deprecate the __mod_term_funcs section on Darwin in the future. This
feature is enabled by default only on Darwin. Users who do not want this
can use command line option 'fno_register_global_dtors_with_atexit' to
disable it.
rdar://problem/33887655
Differential Revision: https://reviews.llvm.org/D45578
llvm-svn: 330199
the tail padding is not reused.
We track on the AggValueSlot (and through a couple of other
initialization actions) whether we're dealing with an object that might
share its tail padding with some other object, so that we can avoid
emitting stores into the tail padding if that's the case. We still
widen stores into tail padding when we can do so.
Differential Revision: https://reviews.llvm.org/D45306
llvm-svn: 329342
Summary:
Add support for the -fsanitize=shadow-call-stack flag which causes clang
to add ShadowCallStack attribute to functions compiled with that flag
enabled.
Reviewers: pcc, kcc
Reviewed By: pcc, kcc
Subscribers: cryptoad, cfe-commits, kcc
Differential Revision: https://reviews.llvm.org/D44801
llvm-svn: 329122
When the declare target variables are emitted for the device,
constructors|destructors for these variables must emitted and registered
by the runtime in the offloading sections.
llvm-svn: 328705
ARC mode.
Declaring __strong pointer fields in structs was not allowed in
Objective-C ARC until now because that would make the struct non-trivial
to default-initialize, copy/move, and destroy, which is not something C
was designed to do. This patch lifts that restriction.
Special functions for non-trivial C structs are synthesized that are
needed to default-initialize, copy/move, and destroy the structs and
manage the ownership of the objects the __strong pointer fields point
to. Non-trivial structs passed to functions are destructed in the callee
function.
rdar://problem/33599681
Differential Revision: https://reviews.llvm.org/D41228
llvm-svn: 326307
only.
Added support for -fopenmp-simd option that allows compilation of
simd-based constructs without emission of OpenMP runtime calls.
llvm-svn: 321560
Summary:
This is the follow-up patch to D37924.
This change refactors clang to use the the newly added section headers
in SpecialCaseList to specify which sanitizers blacklists entries
should apply to, like so:
[cfi-vcall]
fun:*bad_vcall*
[cfi-derived-cast|cfi-unrelated-cast]
fun:*bad_cast*
The SanitizerSpecialCaseList class has been added to allow querying by
SanitizerMask, and SanitizerBlacklist and its downstream users have been
updated to provide that information. Old blacklists not using sections
will continue to function identically since the blacklist entries will
be placed into a '[*]' section by default matching against all
sanitizers.
Reviewers: pcc, kcc, eugenis, vsk
Reviewed By: eugenis
Subscribers: dberris, cfe-commits, mgorny
Differential Revision: https://reviews.llvm.org/D37925
llvm-svn: 314171
This allows multi-module / incremental compilation environments to have unique
initializer symbols.
Patch by Axel Naumann with minor modifications by me!
llvm-svn: 311844
The initializer for a static local variable cannot be hot, because it runs at
most once per program. That's not quite the same thing as having a low branch
probability, but under the assumption that the function is invoked many times,
modeling this as a branch probability seems reasonable.
For TLS variables, the situation is less clear, since the initialization side
of the branch can run multiple times in a program execution, but we still
expect initialization to be rare relative to non-initialization uses. It would
seem worthwhile to add a PGO counter along this path to make this estimation
more accurate in future.
For globals with guarded initialization, we don't yet apply any branch weights.
Due to our use of COMDATs, the guard will be reached exactly once per DSO, but
we have no idea how many DSOs will define the variable.
llvm-svn: 309195
Summary:
If the first parameter of the function is the ImplicitParamDecl, codegen
automatically marks it as an implicit argument with `this` or `self`
pointer. Added internal kind of the ImplicitParamDecl to separate
'this', 'self', 'vtt' and other implicit parameters from other kind of
parameters.
Reviewers: rjmccall, aaron.ballman
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D33735
llvm-svn: 305075
* Do not initialize these variables when initializing the rest of the
thread_locals in the TU; they have unordered initialization so they can be
initialized by themselves.
This fixes a rejects-valid bug: we would make the per-variable initializer
function internal, but put it in a comdat keyed off the variable, resulting
in link errors when the comdat is selected from a different TU (as the per
TU TLS init function tries to call an init function that does not exist).
* On Darwin, when we decide that we're not going to emit a thread wrapper
function at all, demote its linkage to External. Fixes a verifier failure
on explicit instantiation of a thread_local variable on Darwin.
llvm-svn: 291865
Properly attribute DLL storage to runtime functions. When generating the
runtime function, scan for an existing declaration which may provide an explicit
declaration (local storage) or a DLL import or export storage from the user.
Honour that if available. Otherwise, if building with a local visibility of the
public or standard namespaces (-flto-visibility-public-std), give the symbols
local storage (it indicates a /MT[d] link, so static runtime). Otherwise,
assume that the link is dynamic, and give the runtime function dllimport
storage.
This allows for implementations to get the correct storage as long as they are
properly declared, the user to override the import storage, and in case no
explicit storage is given, use of the import storage.
llvm-svn: 289776
This change depends on the corresponding LLVM change at:
https://reviews.llvm.org/D22519
The llvm.invariant.start and llvm.invariant.end intrinsics currently
support specifying invariant memory objects only in the default address
space.
With this LLVM change, these intrinsics are overloaded for any adddress space
for memory objects and we can use these llvm invariant intrinsics in
non-default address spaces.
Example: llvm.invariant.start.p1i8(i64 4, i8 addrspace(1)* %ptr)
This overloaded intrinsic is needed for representing final or invariant
memory in managed languages.
llvm-svn: 276448
The export side is responsible for running any initializers, they are
run when the module is first loaded. Attempting to run an initializer
for the import side is not possible.
This fixes PR28216.
llvm-svn: 273237
Summary:
For a static object with a nontrivial destructor, clang generates an
initializer function (__cxx_global_var_init) which registers that
object's destructor using __cxa_atexit. However some ABIs (ARM,
WebAssembly) use destructors that return 'this' instead of having void
return (which does not match the signature of function pointers passed
to __cxa_atexit). This results in undefined behavior when the destructors are
called. All the calling conventions I know of on ARM can tolerate this,
but WebAssembly requires the signatures of indirect calls to match the
called function.
This patch disables that direct registration of destructors for ABIs
that have this-returning destructors.
Subscribers: aemerson, jfb, cfe-commits, dschuff
Differential Revision: http://reviews.llvm.org/D19275
llvm-svn: 269085
Revert the two changes to thread CodeGenOptions into the TargetInfo allocation
and to fix the layering violation by moving CodeGenOptions into Basic.
Code Generation is arguably not particularly "basic". This addresses Richard's
post-commit review comments. This change purely does the mechanical revert and
will be followed up with an alternate approach to thread the desired information
into TargetInfo.
llvm-svn: 265806
This is a mechanical move of CodeGenOptions from libFrontend to libBasic. This
fixes the layering violation introduced earlier by threading CodeGenOptions into
TargetInfo. It should also fix the modules based self-hosting builds. NFC.
llvm-svn: 265702
In general CUDA does not allow dynamic initialization of
global device-side variables. One exception is that CUDA allows
records with empty constructors as described in section E2.2.1 of
CUDA 7.5 Programming guide.
This patch applies initializer checks for all device-side variables.
Empty constructors are accepted, but no code is generated for them.
Differential Revision: http://reviews.llvm.org/D15305
llvm-svn: 259592
We used to emit the store prior to branch in the entry block. To make it more
efficient, this commit moves it to the init block. We still mark as initialized
before initializing anything else.
llvm-svn: 252777
attributes to internal functions.
This patch fixes CodeGenModule::CreateGlobalInitOrDestructFunction to
use SetInternalFunctionAttributes instead of SetLLVMFunctionAttributes
to attach function attributes to internal functions.
Also, make sure the correct CGFunctionInfo is passed instead of always
passing what arrangeNullaryFunction returns.
rdar://problem/20828324
Differential Revision: http://reviews.llvm.org/D13610
llvm-svn: 251734
Introduce an Address type to bundle a pointer value with an
alignment. Introduce APIs on CGBuilderTy to work with Address
values. Change core APIs on CGF/CGM to traffic in Address where
appropriate. Require alignments to be non-zero. Update a ton
of code to compute and propagate alignment information.
As part of this, I've promoted CGBuiltin's EmitPointerWithAlignment
helper function to CGF and made use of it in a number of places in
the expression emitter.
The end result is that we should now be significantly more correct
when performing operations on objects that are locally known to
be under-aligned. Since alignment is not reliably tracked in the
type system, there are inherent limits to this, but at least we
are no longer confused by standard operations like derived-to-base
conversions and array-to-pointer decay. I've also fixed a large
number of bugs where we were applying the complete-object alignment
to a pointer instead of the non-virtual alignment, although most of
these were hidden by the very conservative approach we took with
member alignment.
Also, because IRGen now reliably asserts on zero alignments, we
should no longer be subject to an absurd but frustrating recurring
bug where an incomplete type would report a zero alignment and then
we'd naively do a alignmentAtOffset on it and emit code using an
alignment equal to the largest power-of-two factor of the offset.
We should also now be emitting much more aggressive alignment
attributes in the presence of over-alignment. In particular,
field access now uses alignmentAtOffset instead of min.
Several times in this patch, I had to change the existing
code-generation pattern in order to more effectively use
the Address APIs. For the most part, this seems to be a strict
improvement, like doing pointer arithmetic with GEPs instead of
ptrtoint. That said, I've tried very hard to not change semantics,
but it is likely that I've failed in a few places, for which I
apologize.
ABIArgInfo now always carries the assumed alignment of indirect and
indirect byval arguments. In order to cut down on what was already
a dauntingly large patch, I changed the code to never set align
attributes in the IR on non-byval indirect arguments. That is,
we still generate code which assumes that indirect arguments have
the given alignment, but we don't express this information to the
backend except where it's semantically required (i.e. on byvals).
This is likely a minor regression for those targets that did provide
this information, but it'll be trivial to add it back in a later
patch.
I partially punted on applying this work to CGBuiltin. Please
do not add more uses of the CreateDefaultAligned{Load,Store}
APIs; they will be going away eventually.
llvm-svn: 246985
This patch adds initial support for the -fsanitize=kernel-address flag to Clang.
Right now it's quite restricted: only out-of-line instrumentation is supported, globals are not instrumented, some GCC kasan flags are not supported.
Using this patch I am able to build and boot the KASan tree with LLVMLinux patches from github.com/ramosian-glider/kasan/tree/kasan_llvmlinux.
To disable KASan instrumentation for a certain function attribute((no_sanitize("kernel-address"))) can be used.
llvm-svn: 240131
This patch adds the -fsanitize=safe-stack command line argument for clang,
which enables the Safe Stack protection (see http://reviews.llvm.org/D6094
for the detailed description of the Safe Stack).
This patch is our implementation of the safe stack on top of Clang. The
patches make the following changes:
- Add -fsanitize=safe-stack and -fno-sanitize=safe-stack options to clang
to control safe stack usage (the safe stack is disabled by default).
- Add __attribute__((no_sanitize("safe-stack"))) attribute to clang that can be
used to disable the safe stack for individual functions even when enabled
globally.
Original patch by Volodymyr Kuznetsov and others at the Dependable Systems
Lab at EPFL; updates and upstreaming by myself.
Differential Revision: http://reviews.llvm.org/D6095
llvm-svn: 239762
Otherwise -fno-omit-frame-pointer and other flags like it aren't
applied.
Basic idea taken from Gao's patch, thanks!
Differential Revision: http://reviews.llvm.org/D9203
llvm-svn: 235537
Reverts the code changes from r234675 but keeps the test case.
We were already maintaining a DenseMap of globals with dynamic
initializers anyway.
Fixes the test case from PR23234.
llvm-svn: 234961
Summary:
Due to CUDA's implicit address space casting, the type of a static local
variable may be more specific (i.e. with address space qualifiers) than
the type expected by the constructor. Emit an addrspacecast in that
case.
Test Plan: Clang used to crash on the added test.
Reviewers: nlewycky, pcc, eliben, rsmith
Reviewed By: eliben, rsmith
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D8575
llvm-svn: 233208
distinction between the different use-cases. With the previous default
behavior we would occasionally emit empty debug locations in situations
where they actually were strictly required (= on invoke insns).
We now have a choice between defaulting to an empty location or an
artificial location.
Specifically, this fixes a bug caused by a missing debug location when
emitting C++ EH cleanup blocks from within an artificial function, such as
an ObjC destroy helper function.
rdar://problem/19670595
llvm-svn: 228003
Several pieces of code were relying on implicit debug location setting
which usually lead to incorrect line information anyway. So I've fixed
those (in r225955 and r225845) separately which should pave the way for
this commit to be cleanly reapplied.
The reason these implicit dependencies resulted in crashes with this
patch is that the debug location would no longer implicitly leak from
one place to another, but be set back to invalid. Once a call with
no/invalid location was emitted, if that call was ever inlined it could
produce invalid debugloc chains and assert during LLVM's codegen.
There may be further cases of such bugs in this patch - they're hard to
flush out with regression testing, so I'll keep an eye out for reports
and investigate/fix them ASAP if they come up.
Original commit message:
Reapply "DebugInfo: Generalize debug info location handling"
Originally committed in r224385 and reverted in r224441 due to concerns
this change might've introduced a crash. Turns out this change fixes the
crash introduced by one of my earlier more specific location handling
changes (those specific fixes are reverted by this patch, in favor of
the more general solution).
Recommitted in r224941 and reverted in r224970 after it caused a crash
when building compiler-rt. Looks to be due to this change zeroing out
the debug location when emitting default arguments (which were meant to
inherit their outer expression's location) thus creating call
instructions without locations - these create problems for inlining and
must not be created. That is fixed and tested in this version of the
change.
Original commit message:
This is a more scalable (fixed in mostly one place, rather than many
places that will need constant improvement/maintenance) solution to
several commits I've made recently to increase source fidelity for
subexpressions.
This resetting had to be done at the DebugLoc level (not the
SourceLocation level) to preserve scoping information (if the resetting
was done with CGDebugInfo::EmitLocation, it would've caused the tail end
of an expression's codegen to end up in a potentially different scope
than the start, even though it was at the same source location). The
drawback to this is that it might leave CGDebugInfo out of sync. Ideally
CGDebugInfo shouldn't have a duplicate sense of the current
SourceLocation, but for now it seems it does... - I don't think I'm
going to tackle removing that just now.
I expect this'll probably cause some more buildbot fallout & I'll
investigate that as it comes up.
Also these sort of improvements might be starting to show a weakness/bug
in LLVM's line table handling: we don't correctly emit is_stmt for
statements, we just put it on every line table entry. This means one
statement split over multiple lines appears as multiple 'statements' and
two statements on one line (without column info) are treated as one
statement.
I don't think we have any IR representation of statements that would
help us distinguish these cases and identify the beginning of each
statement - so that might be something we need to add (possibly to the
lexical scope chain - a scope for each statement). This does cause some
problems for GDB and possibly other DWARF consumers.
llvm-svn: 225956
Without setting the CurEHLocation these cleanups would be attributed to
whatever the last active debug line location was (the 'fn' call in the
included test cases). By setting CurEHLocation correctly the line
information is improved/corrected.
This quality bug turned into a crasher with r225000 when, instead of
allowing the last location to persist, it would be zero'd out. This
could lead to a function call (such as the dtor) being made without a
debug location - if that call was subsequently inlined (and the caller
and callee had debug info, just not the call instruction) the inliner
would violate important constraints about the debug location chains by
not updating the inlined instructions to chain up to the callee
locations.
So, by fixing this bug, I am addressing the assertion failures
introduced by r225000 and should be able to recommit that patch with
impunity...
llvm-svn: 225955
The llvm IR until recently had no support for comdats. This was a problem when
targeting C++ on ELF/COFF as just using weak linkage would cause quite a bit of
dead bits to remain on the executable (unless -ffunction-sections,
-fdata-sections and --gc-sections were used).
To fix the problem, llvm's codegen will just assume that any weak or linkonce
that is not in an explicit comdat should be output in one with the same name as
the global.
This unfortunately breaks cases like pr19848 where a weak symbol is not
xpected to be part of any comdat.
Now that we have explicit comdats in the IR, we can finally get both cases
right.
This first patch just makes clang give explicit comdats to GlobalValues where
t is allowed to.
A followup patch to llvm will then stop implicitly producing comdats.
llvm-svn: 225705
Akira Hatanaka