CodeGenFunction::EmitTypeCheck accepts a bool flag which controls
whether or not null checks are emitted. Make this a bit more flexible by
changing the bool to a SanitizerSet.
Needed for an upcoming change which deals with a scenario in which we
only want to emit null checks.
llvm-svn: 295514
Guard against a null pointer dereference that caused Clang to crash
when processing a class containing an _Atomic qualified data member,
and that is tagged with 'dllexport'.
Differential Revision: https://reviews.llvm.org/D29208
llvm-svn: 293911
clang-cl would evaluate the arguments right-to-left (see PR), and for
non-Windows targets I suppose we only got it because we were already
emitting left-to-right in CodeGenFunction::EmitCallArgs.
Differential Revision: https://reviews.llvm.org/D29350
llvm-svn: 293732
copy constructors of classes with array members, instead using
ArrayInitLoopExpr to represent the initialization loop.
This exposed a bug in the static analyzer where it was unable to differentiate
between zero-initialized and unknown array values, which has also been fixed
here.
llvm-svn: 289618
This adds a way for us to version any UBSan handler by itself.
The patch overrides D21289 for a better implementation (we're able to
rev up a single handler).
After this, then we can land a slight modification of D19667+D19668.
We probably don't want to keep all the versions in compiler-rt (maybe we
want to deprecate on one release and remove the old handler on the next
one?), but with this patch we will loudly fail to compile when mixing
incompatible handler calls, instead of silently compiling and then
providing bad error messages.
Reviewers: kcc, samsonov, rsmith, vsk
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D21695
llvm-svn: 289444
function. In that case, there is no requirement that the callee is actually
defined, and the code may in fact be valid and have defined behavior if the
virtual call is unreachable.
llvm-svn: 286534
* if the base is produced by a series of derived-to-base conversions, check
the expression inside them when looking for an expression with a known
dynamic type
* step past MaterializeTemporaryExprs when checking for a known dynamic type
* when checking for a known dynamic type, treat all class prvalues as having
a known dynamic type after skipping all relevant rvalue subobject
adjustments
* treat callees formed by pointer-to-member access for a non-reference member
type like callees formed by member access.
llvm-svn: 285954
abstract information about the callee. NFC.
The goal here is to make it easier to recognize indirect calls and
trigger additional logic in certain cases. That logic will come in
a later patch; in the meantime, I felt that this was a significant
improvement to the code.
llvm-svn: 285258
If we see a virtual method call to Base::foo() but can infer that the
object is an instance of Derived, and that 'foo' is marked 'final' in
Derived, we can devirtualize the call to Derived::foo().
Differential Revision: https://reviews.llvm.org/D25813
llvm-svn: 284766
Replace inheriting constructors implementation with new approach, voted into
C++ last year as a DR against C++11.
Instead of synthesizing a set of derived class constructors for each inherited
base class constructor, we make the constructors of the base class visible to
constructor lookup in the derived class, using the normal rules for
using-declarations.
For constructors, UsingShadowDecl now has a ConstructorUsingShadowDecl derived
class that tracks the requisite additional information. We create shadow
constructors (not found by name lookup) in the derived class to model the
actual initialization, and have a new expression node,
CXXInheritedCtorInitExpr, to model the initialization of a base class from such
a constructor. (This initialization is special because it performs real perfect
forwarding of arguments.)
In cases where argument forwarding is not possible (for inalloca calls,
variadic calls, and calls with callee parameter cleanup), the shadow inheriting
constructor is not emitted and instead we directly emit the initialization code
into the caller of the inherited constructor.
Note that this new model is not perfectly compatible with the old model in some
corner cases. In particular:
* if B inherits a private constructor from A, and C uses that constructor to
construct a B, then we previously required that A befriends B and B
befriends C, but the new rules require A to befriend C directly, and
* if a derived class has its own constructors (and so its implicit default
constructor is suppressed), it may still inherit a default constructor from
a base class
llvm-svn: 274049
It makes compiler-rt tests fail if the gold plugin is enabled.
Revert "Rework interface for bitset-using features to use a notion of LTO visibility."
Revert "Driver: only produce CFI -fvisibility= error when compiling."
Revert "clang/test/CodeGenCXX/cfi-blacklist.cpp: Exclude ms targets. They would be non-cfi."
llvm-svn: 267871
Bitsets, and the compiler features they rely on (vtable opt, CFI),
only have visibility within the LTO'd part of the linkage unit. Therefore,
only enable these features for classes with hidden LTO visibility. This
notion is based on object file visibility or (on Windows)
dllimport/dllexport attributes.
We provide the [[clang::lto_visibility_public]] attribute to override the
compiler's LTO visibility inference in cases where the class is defined
in the non-LTO'd part of the linkage unit, or where the ABI supports
calling classes derived from abstract base classes with hidden visibility
in other linkage units (e.g. COM on Windows).
If the cross-DSO CFI mode is enabled, bitset checks are emitted even for
classes with public LTO visibility, as that mode uses a separate mechanism
to cause bitsets to be exported.
This mechanism replaces the whole-program-vtables blacklist, so remove the
-fwhole-program-vtables-blacklist flag.
Because __declspec(uuid()) now implies [[clang::lto_visibility_public]], the
support for the special attr:uuid blacklist entry is removed.
Differential Revision: http://reviews.llvm.org/D18635
llvm-svn: 267784
of a table entry in the corresponding decl, store an offset from the current
record to the relevant CXX_CTOR_INITIALIZERS record. This results in fewer
indirections and a minor .pcm file size reduction.
llvm-svn: 266254
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
This patch introduces the -fwhole-program-vtables flag, which enables the
whole-program vtable optimization feature (D16795) in Clang.
Differential Revision: http://reviews.llvm.org/D16821
llvm-svn: 261767
Avoid crashing when printing diagnostics for vtable-related CFI
errors. In diagnostic mode, the frontend does an additional check of
the vtable pointer against the set of all known vtable addresses and
lets the runtime handler know if it is safe to inspect the vtable.
http://reviews.llvm.org/D16823
llvm-svn: 259716
* Runtime diagnostic data for cfi-icall changed to match the rest of
cfi checks
* Layout of all CFI diagnostic data changed to put Kind at the
beginning. There is no ABI stability promise yet.
* Call cfi_slowpath_diag instead of cfi_slowpath when needed.
* Emit __cfi_check_fail function, which dispatches a CFI check
faliure according to trap/recover settings of the current module.
* A tiny driver change to match the way the new handlers are done in
compiler-rt.
llvm-svn: 258745
This is part of a new statistics gathering feature for the sanitizers.
See clang/docs/SanitizerStats.rst for further info and docs.
Differential Revision: http://reviews.llvm.org/D16175
llvm-svn: 257971
Clang-side cross-DSO CFI.
* Adds a command line flag -f[no-]sanitize-cfi-cross-dso.
* Links a runtime library when enabled.
* Emits __cfi_slowpath calls is bitset test fails.
* Emits extra hash-based bitsets for external CFI checks.
* Sets a module flag to enable __cfi_check generation during LTO.
This mode does not yet support diagnostics.
llvm-svn: 255694
Ensure that the vptr store in the most-derived constructor is not behind
an invariant group barrier. Previously, the base-most vptr store would
be the one behind no barrier, and that could result in the creator of
the object thinking it had the base-most vtable.
This bug caused clang call pure virtual functions when called from
constructor body.
http://reviews.llvm.org/D13373
llvm-svn: 249197
ptr in dtor.
Summary:
After destruction, invocation of virtual functions prevented
by poisoning vtable pointer.
Reviewers: eugenis, kcc
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D12712
Fixed testing callback emission order to account for vptr.
Poison vtable in either complete or base dtor, depending on
if virtual bases exist. If virtual bases exist, poison in
complete dtor. Otherwise, poison in base.
Remove commented-out block.
llvm-svn: 247762
Current implementation may end up emitting an undefined reference for
an "inline __attribute__((always_inline))" function by generating an
"available_externally alwaysinline" IR function for it and then failing to
inline all the calls. This happens when a call to such function is in dead
code. As the inliner is an SCC pass, it does not process dead code.
Libc++ relies on the compiler never emitting such undefined reference.
With this patch, we emit a pair of
1. internal alwaysinline definition (called F.alwaysinline)
2a. A stub F() { musttail call F.alwaysinline }
-- or, depending on the linkage --
2b. A declaration of F.
The frontend ensures that F.inlinefunction is only used for direct
calls, and the stub is used for everything else (taking the address of
the function, really). Declaration (2b) is emitted in the case when
"inline" is meant for inlining only (like __gnu_inline__ and some
other cases).
This approach, among other nice properties, ensures that alwaysinline
functions are always internal, making it impossible for a direct call
to such function to produce an undefined symbol reference.
This patch is based on ideas by Chandler Carruth and Richard Smith.
llvm-svn: 247494
Current implementation may end up emitting an undefined reference for
an "inline __attribute__((always_inline))" function by generating an
"available_externally alwaysinline" IR function for it and then failing to
inline all the calls. This happens when a call to such function is in dead
code. As the inliner is an SCC pass, it does not process dead code.
Libc++ relies on the compiler never emitting such undefined reference.
With this patch, we emit a pair of
1. internal alwaysinline definition (called F.alwaysinline)
2a. A stub F() { musttail call F.alwaysinline }
-- or, depending on the linkage --
2b. A declaration of F.
The frontend ensures that F.inlinefunction is only used for direct
calls, and the stub is used for everything else (taking the address of
the function, really). Declaration (2b) is emitted in the case when
"inline" is meant for inlining only (like __gnu_inline__ and some
other cases).
This approach, among other nice properties, ensures that alwaysinline
functions are always internal, making it impossible for a direct call
to such function to produce an undefined symbol reference.
This patch is based on ideas by Chandler Carruth and Richard Smith.
llvm-svn: 247465
It seems that there is small bug, and we can't generate assume loads
when some virtual functions have internal visibiliy
This reverts commit 982bb7d966947812d216489b3c519c9825cacbf2.
llvm-svn: 247332
This flag causes the compiler to emit bit set entries for functions as well
as runtime bitset checks at indirect call sites. Depends on the new function
bitset mechanism.
Differential Revision: http://reviews.llvm.org/D11857
llvm-svn: 247238
Generating call assume(icmp %vtable, %global_vtable) after constructor
call for devirtualization purposes.
For more info go to:
http://lists.llvm.org/pipermail/cfe-dev/2015-July/044227.html
Edit:
Fixed version because of PR24479.
After this patch got reverted because of ScalarEvolution bug (D12719)
Merged after John McCall big patch (Added Address).
http://reviews.llvm.org/D11859
llvm-svn: 247199
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
Summary:
Dtor sanitization handled amidst other dtor cleanups,
between cleaning bases and fields. Sanitizer call pushed onto
stack of cleanup operations.
Reviewers: eugenis, kcc
Differential Revision: http://reviews.llvm.org/D12022
Refactoring dtor sanitizing emission order.
- Support multiple inheritance by poisoning after
member destructors are invoked, and before base
class destructors are invoked.
- Poison for virtual destructor and virtual bases.
- Repress dtor aliasing when sanitizing in dtor.
- CFE test for dtor aliasing, and repression of aliasing in dtor
code generation.
- Poison members on field-by-field basis, with collective poisoning
of trivial members when possible.
- Check msan flags and existence of fields, before dtor sanitizing,
and when determining if aliasing is allowed.
- Testing sanitizing bit fields.
llvm-svn: 246815
Vedant Kumar