Commit Graph

401 Commits

Author SHA1 Message Date
Rumeet Dhindsa a1d688dfdd Revert Devirtualize destructor of final class.
This reverts r364100 (git commit 405c2b1622)

llvm-svn: 364359
2019-06-25 22:58:25 +00:00
Hiroshi Yamauchi 405c2b1622 Devirtualize destructor of final class.
Summary:
Take advantage of the final keyword to devirtualize destructor calls.

Fix https://bugs.llvm.org/show_bug.cgi?id=21368

Reviewers: rsmith

Reviewed By: rsmith

Subscribers: davidxl, Prazek, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D63161

llvm-svn: 364100
2019-06-21 20:04:29 +00:00
Richard Smith b9fb121a62 [c++20] Implement P1009R2: allow omitting the array bound in an array
new expression.

This was voted into C++20 as a defect report resolution, so we
retroactively apply it to all prior language modes (though it can never
actually be used before C++11 mode).

llvm-svn: 360006
2019-05-06 03:47:15 +00:00
Anastasia Stulova 094c72660a [PR41276] Fixed incorrect generation of addr space cast for 'this' in C++.
Improved classification of address space cast when qualification
conversion is performed - prevent adding addr space cast for
non-pointer and non-reference types. Take address space correctly
from the pointee.

Also pass correct address space from 'this' object using
AggValueSlot when generating addrspacecast in the constructor
call.

Differential Revision: https://reviews.llvm.org/D59988

llvm-svn: 357682
2019-04-04 10:48:36 +00:00
Peter Collingbourne d1c5b28c2a IRGen: Remove StructorType; thread GlobalDecl through more code. NFCI.
This should make it easier to add more structor variants.

Differential Revision: https://reviews.llvm.org/D59724

llvm-svn: 356822
2019-03-22 23:05:10 +00:00
James Y Knight ab4f7f144a Fix MSVC constructor call extension after b92d290e48 (r353181).
The assert added to EmitCall there was triggering in Windows Chromium
builds, due to a mismatch of the return type.

The MSVC constructor call extension (`this->Foo::Foo()`) was emitting
the constructor call from 'EmitCXXMemberOrOperatorMemberCallExpr' via
calling 'EmitCXXMemberOrOperatorCall', instead of
'EmitCXXConstructorCall'. On targets where HasThisReturn is true, that
was failing to set the proper return type in the call info.

Switching to calling EmitCXXConstructorCall also allowed removing some
code e.g. the trivial copy/move support, which is already handled in
EmitCXXConstructorCall.

Ref: https://bugs.chromium.org/p/chromium/issues/detail?id=928861
Differential Revision: https://reviews.llvm.org/D57794

llvm-svn: 353246
2019-02-06 00:06:03 +00:00
James Y Knight b92d290e48 [opaque pointer types] Fix the CallInfo passed to EmitCall in some
edge cases.

Currently, EmitCall emits a call instruction with a function type
derived from the pointee-type of the callee. This *should* be the same
as the type created from the CallInfo parameter, but in some cases an
incorrect CallInfo was being passed.

All of these fixes were discovered by the addition of the assert in
EmitCall which verifies that the passed-in CallInfo matches the
Callee's function type.

As far as I know, these issues caused no bugs at the moment, as the
correct types were ultimately being emitted. But, some would become
problematic when pointee types are removed.

List of fixes:

* arrangeCXXConstructorCall was passing an incorrect value for the
  number of Required args, when calling an inheriting constructor
  where the inherited constructor is variadic. (The inheriting
  constructor doesn't actually get passed any of the user's args, but
  the code was calculating it as if it did).

* arrangeFreeFunctionLikeCall was not including the count of the
  pass_object_size arguments in the count of required args.

* OpenCL uses other address spaces for the "this" pointer. However,
  commonEmitCXXMemberOrOperatorCall was not annotating the address
  space on the "this" argument of the call.

* Destructor calls were being created with EmitCXXMemberOrOperatorCall
  instead of EmitCXXDestructorCall in a few places. This was a problem
  because the calling convention sometimes has destructors returning
  "this" rather than void, and the latter function knows about that,
  and sets up the types properly (through calling
  arrangeCXXStructorDeclaration), while the former does not.

* generateObjCGetterBody: the 'objc_getProperty' function returns type
  'id', but was being called as if it returned the particular
  property's type. (That is of course the *dynamic* return type, and
  there's a downcast immediately after.)

* OpenMP user-defined reduction functions (#pragma omp declare
  reduction) can be called with a subclass of the declared type. In
  such case, the call was being setup as if the function had been
  actually declared to take the subtype, rather than the base type.

Differential Revision: https://reviews.llvm.org/D57664

llvm-svn: 353181
2019-02-05 16:05:50 +00:00
James Y Knight 8799caee8d [opaque pointer types] Trivial changes towards CallInst requiring
explicit function types.

llvm-svn: 353009
2019-02-03 21:53:49 +00:00
James Y Knight 916db651c8 Remove redundant FunctionDecl argument from a couple functions.
This argument was added in r254554 in order to support the
pass_object_size attribute. However, in r296076, the attribute's
presence is now also represented in FunctionProtoType's
ExtParameterInfo, and thus it's unnecessary to pass along a separate
FunctionDecl.

The functions modified are:
 RequiredArgs::forPrototype{,Plus}, and
 CodeGenTypes::ConvertFunctionType.

After this, it's also (again) unnecessary to have a separate
ConvertFunctionType function ConvertType, so convert callers back to
the latter, leaving the former as an internal helper function.

llvm-svn: 352946
2019-02-02 01:48:23 +00:00
James Y Knight 3933addd30 Cleanup: replace uses of CallSite with CallBase.
llvm-svn: 352595
2019-01-30 02:54:28 +00:00
Richard Smith cfa79b27b5 [ubsan] Check the correct size when sanitizing array new.
We previously forgot to multiply the element size by the array bound.

llvm-svn: 351924
2019-01-23 03:37:29 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Richard Smith 0444006fff Fix cleanup registration for lambda captures.
Lambda captures should be destroyed if an exception is thrown only if
the construction of the complete lambda-expression has not completed.
(If the lambda-expression has been fully constructed, any exception will
invoke its destructor, which will destroy the captures.)

This is directly modeled after how we handle the equivalent situation in
InitListExprs.

Note that EmitLambdaLValue was unreachable because in C++11 onwards the
frontend never creates the awkward situation where a prvalue expression
(such as a lambda) is used in an lvalue context (such as the left-hand
side of a class member access).

llvm-svn: 351487
2019-01-17 22:05:50 +00:00
Richard Smith 2f72a7521a In nothrow new-expressions, null-check the result if we're going to
apply sanitizers to it.

This avoids a sanitizer false positive that we are initializing a null
pointer.

llvm-svn: 350779
2019-01-10 00:03:29 +00:00
Bruno Ricci 9b6dfac5ad [AST] Store some data of CXXNewExpr as trailing objects
Store the optional array size expression, optional initialization expression
and optional placement new arguments in a trailing array. Additionally store
the range for the parenthesized type-id in a trailing object if needed since
in the vast majority of cases the type is not parenthesized (not a single new
expression in the translation unit of SemaDecl.cpp has a parenthesized type-id).

This saves 2 pointers per CXXNewExpr in all cases, and 2 pointers + 8 bytes
per CXXNewExpr in the common case where the type is not parenthesized.

Differential Revision: https://reviews.llvm.org/D56134

Reviewed By: rjmccall

llvm-svn: 350527
2019-01-07 15:04:45 +00:00
Richard Trieu 6368818fd5 Move CodeGenOptions from Frontend to Basic
Basic uses CodeGenOptions and should not depend on Frontend.

llvm-svn: 348827
2018-12-11 03:18:39 +00:00
Erich Keane de6480a38c [NFC] Move storage of dispatch-version to GlobalDecl
As suggested by Richard Smith, and initially put up for review here:
https://reviews.llvm.org/D53341, this patch removes a hack that was used
to ensure that proper target-feature lists were used when emitting
cpu-dispatch (and eventually, target-clones) implementations. As a part
of this, the GlobalDecl object is proliferated to a bunch more
locations.

Originally, this was put up for review (see above) to get acceptance on
the approach, though discussion with Richard in San Diego showed he
approved of the approach taken here.  Thus, I believe this is acceptable
for Review-After-commit

Differential Revision: https://reviews.llvm.org/D53341

Change-Id: I0a0bd673340d334d93feac789d653e03d9f6b1d5
llvm-svn: 346757
2018-11-13 15:48:08 +00:00
Richard Smith b3d203ff7f PR24164, PR39336: init-captures are not distinct full-expressions.
Rather, they are subexpressions of the enclosing lambda-expression, and
any temporaries in them are destroyed at the end of that
full-expression, or when the corresponding lambda-expression is
destroyed if they are lifetime-extended.

llvm-svn: 344801
2018-10-19 19:01:34 +00:00
Stephen Kelly f2ceec4811 Port getLocStart -> getBeginLoc
Reviewers: teemperor!

Subscribers: jholewinski, whisperity, jfb, cfe-commits

Differential Revision: https://reviews.llvm.org/D50350

llvm-svn: 339385
2018-08-09 21:08:08 +00:00
Fangrui Song 6907ce2f8f Remove trailing space
sed -Ei 's/[[:space:]]+$//' include/**/*.{def,h,td} lib/**/*.{cpp,h}

llvm-svn: 338291
2018-07-30 19:24:48 +00:00
Serge Pavlov 376051820d [UBSan] Strengthen pointer checks in 'new' expressions
With this change compiler generates alignment checks for wider range
of types. Previously such checks were generated only for the record types
with non-trivial default constructor. So the types like:

    struct alignas(32) S2 { int x; };
    typedef __attribute__((ext_vector_type(2), aligned(32))) float float32x2_t;

did not get checks when allocated by 'new' expression.

This change also optimizes the checks generated for the arrays created
in 'new' expressions. Previously the check was generated for each
invocation of type constructor. Now the check is generated only once
for entire array.

Differential Revision: https://reviews.llvm.org/D49589

llvm-svn: 338199
2018-07-28 15:33:03 +00:00
Piotr Padlewski 5dde809404 Rename invariant.group.barrier to launder.invariant.group
Summary:
This is one of the initial commit of "RFC: Devirtualization v2" proposal:
https://docs.google.com/document/d/16GVtCpzK8sIHNc2qZz6RN8amICNBtvjWUod2SujZVEo/edit?usp=sharing

Reviewers: rsmith, amharc, kuhar, sanjoy

Subscribers: arsenm, nhaehnle, javed.absar, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D45111

llvm-svn: 331448
2018-05-03 11:03:01 +00:00
Richard Smith e78fac5126 PR36992: do not store beyond the dsize of a class object unless we know
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
2018-04-05 20:52:58 +00:00
Eric Fiselier fa752f23cc [Builtins] Overload __builtin_operator_new/delete to allow forwarding to usual allocation/deallocation functions.
Summary:
Libc++'s default allocator uses `__builtin_operator_new` and `__builtin_operator_delete` in order to allow the calls to new/delete to be ellided. However, libc++ now needs to support over-aligned types in the default allocator. In order to support this without disabling the existing optimization Clang needs to support calling the aligned new overloads from the builtins.

See llvm.org/PR22634 for more information about the libc++ bug.

This patch changes `__builtin_operator_new`/`__builtin_operator_delete` to call any usual `operator new`/`operator delete` function. It does this by performing overload resolution with the arguments passed to the builtin to determine which allocation function to call. If the selected function is not a usual allocation function a diagnostic is issued.

One open issue is if the `align_val_t` overloads should be considered "usual" when `LangOpts::AlignedAllocation` is disabled.


In order to allow libc++ to detect this new behavior the value for `__has_builtin(__builtin_operator_new)` has been updated to `201802`.

Reviewers: rsmith, majnemer, aaron.ballman, erik.pilkington, bogner, ahatanak

Reviewed By: rsmith

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D43047

llvm-svn: 328134
2018-03-21 19:19:48 +00:00
Yaxun Liu 5b330e8d61 Recommit r326946 after reducing CallArgList memory footprint
llvm-svn: 327634
2018-03-15 15:25:19 +00:00
Richard Smith 007cb6df58 Revert r326946. It caused stack overflows by significantly increasing the size of a CallArgList.
llvm-svn: 327195
2018-03-10 01:47:22 +00:00
Yaxun Liu 06dd81149f CodeGen: Fix address space of indirect function argument
The indirect function argument is in alloca address space in LLVM IR. However,
during Clang codegen for C++, the address space of indirect function argument
should match its address space in the source code, i.e., default addr space, even
for indirect argument. This is because destructor of the indirect argument may
be called in the caller function, and address of the indirect argument may be
taken, in either case the indirect function argument is expected to be in default
addr space, not the alloca address space.

Therefore, the indirect function argument should be mapped to the temp var
casted to default address space. The caller will cast it to alloca addr space
when passing it to the callee. In the callee, the argument is also casted to the
default address space and used.

CallArg is refactored to facilitate this fix.

Differential Revision: https://reviews.llvm.org/D34367

llvm-svn: 326946
2018-03-07 21:45:40 +00:00
Peter Collingbourne ea21100272 IRGen: Move vtable load after argument evaluation.
This change reduces the live range of the loaded function pointer,
resulting in a slight code size decrease (~10KB in clang), and also
improves the security of CFI for virtual calls by making it less
likely that the function pointer will be spilled, and ensuring that
it is not spilled across a function call boundary.

Fixes PR35353.

Differential Revision: https://reviews.llvm.org/D42725

llvm-svn: 324286
2018-02-05 23:09:13 +00:00
Ivan A. Kosarev 1860b520a2 [CodeGen] Decorate aggregate accesses with TBAA tags
Differential Revision: https://reviews.llvm.org/D41539

llvm-svn: 323421
2018-01-25 14:21:55 +00:00
Stephan Bergmann d71ad177eb -fsanitize=vptr warnings on bad static types in dynamic_cast and typeid
...when such an operation is done on an object during con-/destruction.

This is the cfe part of a patch covering both cfe and compiler-rt.

Differential Revision: https://reviews.llvm.org/D40295

llvm-svn: 321519
2017-12-28 12:45:41 +00:00
Vedant Kumar 09b5bfdd85 [ubsan] Diagnose noreturn functions which return
Diagnose 'unreachable' UB when a noreturn function returns.

  1. Insert a check at the end of functions marked noreturn.

  2. A decl may be marked noreturn in the caller TU, but not marked in
     the TU where it's defined. To diagnose this scenario, strip away the
     noreturn attribute on the callee and insert check after calls to it.

Testing: check-clang, check-ubsan, check-ubsan-minimal, D40700

rdar://33660464

Differential Revision: https://reviews.llvm.org/D40698

llvm-svn: 321231
2017-12-21 00:10:25 +00:00
Adrian Prantl f3b3ccda59 Silence a bunch of implicit fallthrough warnings
llvm-svn: 321115
2017-12-19 22:06:11 +00:00
Peter Collingbourne 6010880bd1 IRGen: When performing CFI checks, load vtable pointer from vbase when necessary.
Under the Microsoft ABI, it is possible for an object not to have
a virtual table pointer of its own if all of its virtual functions
were introduced by virtual bases. In that case, we need to load the
vtable pointer from one of the virtual bases and perform the type
check using its type.

Differential Revision: https://reviews.llvm.org/D41036

llvm-svn: 320638
2017-12-13 21:53:04 +00:00
Richard Smith 5b34958b46 Support for destroying operator delete, per C++2a proposal P0722.
This feature is not (yet) approved by the C++ committee, so this is liable to
be reverted or significantly modified based on committee feedback.

No functionality change intended for existing code (a new type must be defined
in namespace std to take advantage of this feature).

llvm-svn: 315662
2017-10-13 01:55:36 +00:00
John McCall de0fe07eef Extract IRGen's constant-emitter into its own helper class and clean up
the interface.

The ultimate goal here is to make it easier to do some more interesting
things in constant emission, like emit constant initializers that have
ignorable side-effects, or doing the majority of an initialization
in-place and then patching up the last few things with calls.  But for
now this is mostly just a refactoring.

llvm-svn: 310964
2017-08-15 21:42:52 +00:00
Akira Hatanaka 2246167362 [Sema] Mark a virtual CXXMethodDecl as used if a call to it can be
devirtualized.

The code to detect devirtualized calls is already in IRGen, so move the
code to lib/AST and make it a shared utility between Sema and IRGen.

This commit fixes a linkage error I was seeing when compiling the
following code:

$ cat test1.cpp
struct Base {
  virtual void operator()() {}
};

template<class T>
struct Derived final : Base {
  void operator()() override {}
};

Derived<int> *d;

int main() {
  if (d)
    (*d)();
  return 0;
}

rdar://problem/33195657

Differential Revision: https://reviews.llvm.org/D34301

llvm-svn: 307883
2017-07-13 06:08:27 +00:00
Piotr Padlewski 31fd99cf65 [Devirtualization] insert placement new barrier with -O0
Summary:
To not break LTO with different optimizations levels, we should insert
the barrier regardles of optimization level.

Reviewers: rjmccall, rsmith, mehdi_amini

Reviewed By: mehdi_amini

Subscribers: mehdi_amini, cfe-commits

Differential Revision: https://reviews.llvm.org/D32401

llvm-svn: 303488
2017-05-20 08:56:18 +00:00
Krzysztof Parzyszek 8f248234fa [CodeGen] Propagate LValueBaseInfo instead of AlignmentSource
The functions creating LValues propagated information about alignment
source. Extend the propagated data to also include information about
possible unrestricted aliasing. A new class LValueBaseInfo will
contain both AlignmentSource and MayAlias info.

This patch should not introduce any functional changes.

Differential Revision: https://reviews.llvm.org/D33284

llvm-svn: 303358
2017-05-18 17:07:11 +00:00
Vedant Kumar ffd7c887d6 [ubsan] Reduce alignment checking of C++ object pointers
This patch teaches ubsan to insert an alignment check for the 'this'
pointer at the start of each method/lambda. This allows clang to emit
significantly fewer alignment checks overall, because if 'this' is
aligned, so are its fields.

This is essentially the same thing r295515 does, but for the alignment
check instead of the null check. One difference is that we keep the
alignment checks on member expressions where the base is a DeclRefExpr.
There's an opportunity to diagnose unaligned accesses in this situation
(as pointed out by Eli, see PR32630).

Testing: check-clang, check-ubsan, and a stage2 ubsan build.

Along with the patch from D30285, this roughly halves the amount of
alignment checks we emit when compiling X86FastISel.cpp. Here are the
numbers from patched/unpatched clangs based on r298160.

  ------------------------------------------
  | Setup          | # of alignment checks |
  ------------------------------------------
  | unpatched, -O0 |                 24326 |
  | patched, -O0   |                 12717 | (-47.7%)
  ------------------------------------------

Differential Revision: https://reviews.llvm.org/D30283

llvm-svn: 300370
2017-04-14 22:03:34 +00:00
Reid Kleckner de86482ce0 Update Clang for LLVM rename AttributeSet -> AttributeList
llvm-svn: 298394
2017-03-21 16:57:30 +00:00
Vedant Kumar ed00ea084e [ubsan] Extend the nonnull arg check to ObjC
UBSan's nonnull argument check applies when a parameter has the
"nonnull" attribute. The check currently works for FunctionDecls, but
not for ObjCMethodDecls. This patch extends the check to work for ObjC.

Differential Revision: https://reviews.llvm.org/D30599

llvm-svn: 296996
2017-03-06 05:28:22 +00:00
George Burgess IV d0a9e807f3 [CodeGen] Fix ExtParameterInfo bugs in C++ CodeGen code.
This patch makes use of the prefix/suffix ABI argument distinction that
was introduced in r295870, so that we now emit ExtParameterInfo at the
correct offset for member calls that have added ABI arguments. I don't
see a good way to test the generated param info, since we don't actually
seem to use it in CGFunctionInfo outside of Swift. Any
suggestions/thoughts for how to better test this are welcome. :)

This patch also fixes a small bug with inheriting constructors: if we
decide not to pass args into an base class ctor, we would still
generate ExtParameterInfo as though we did. The added test-case is for
that behavior.

llvm-svn: 296024
2017-02-23 22:07:35 +00:00
Vedant Kumar e550d11d34 Rename a helper function, NFC.
llvm-svn: 295918
2017-02-23 01:22:38 +00:00
Vedant Kumar 34b1fd6aaa Retry^2: [ubsan] Reduce null checking of C++ object pointers (PR27581)
This patch teaches ubsan to insert exactly one null check for the 'this'
pointer per method/lambda.

Previously, given a load of a member variable from an instance method
('this->x'), ubsan would insert a null check for 'this', and another
null check for '&this->x', before allowing the load to occur.

Similarly, given a call to a method from another method bound to the
same instance ('this->foo()'), ubsan would a redundant null check for
'this'. There is also a redundant null check in the case where the
object pointer is a reference ('Ref.foo()').

This patch teaches ubsan to remove the redundant null checks identified
above.

Testing: check-clang, check-ubsan, and a stage2 ubsan build.

I also compiled X86FastISel.cpp with -fsanitize=null using
patched/unpatched clangs based on r293572. Here are the number of null
checks emitted:

  -------------------------------------
  | Setup          | # of null checks |
  -------------------------------------
  | unpatched, -O0 |            21767 |
  | patched, -O0   |            10758 |
  -------------------------------------

Changes since the initial commit:
- Don't introduce any unintentional object-size or alignment checks.
- Don't rely on IRGen of C labels in the test.

Differential Revision: https://reviews.llvm.org/D29530

llvm-svn: 295515
2017-02-17 23:22:59 +00:00
Vedant Kumar 29ba8d9bfe Revert "Retry: [ubsan] Reduce null checking of C++ object pointers (PR27581)"
This reverts commit r295401. It breaks the ubsan self-host. It inserts
object size checks once per C++ method which fire when the structure is
empty.

llvm-svn: 295494
2017-02-17 20:59:40 +00:00
Vedant Kumar 55875b9955 Retry: [ubsan] Reduce null checking of C++ object pointers (PR27581)
This patch teaches ubsan to insert exactly one null check for the 'this'
pointer per method/lambda.

Previously, given a load of a member variable from an instance method
('this->x'), ubsan would insert a null check for 'this', and another
null check for '&this->x', before allowing the load to occur.

Similarly, given a call to a method from another method bound to the
same instance ('this->foo()'), ubsan would a redundant null check for
'this'. There is also a redundant null check in the case where the
object pointer is a reference ('Ref.foo()').

This patch teaches ubsan to remove the redundant null checks identified
above.

Testing: check-clang and check-ubsan. I also compiled X86FastISel.cpp
with -fsanitize=null using patched/unpatched clangs based on r293572.
Here are the number of null checks emitted:

  -------------------------------------
  | Setup          | # of null checks |
  -------------------------------------
  | unpatched, -O0 |            21767 |
  | patched, -O0   |            10758 |
  -------------------------------------

Changes since the initial commit: don't rely on IRGen of C labels in the
test.

Differential Revision: https://reviews.llvm.org/D29530

llvm-svn: 295401
2017-02-17 02:03:51 +00:00
Vedant Kumar 4f94a94bea Revert "[ubsan] Reduce null checking of C++ object pointers (PR27581)"
This reverts commit r295391. It breaks this bot:

http://lab.llvm.org:8011/builders/clang-with-thin-lto-ubuntu/builds/1898

I need to not rely on labels in the IR test.

llvm-svn: 295396
2017-02-17 01:42:36 +00:00
Vedant Kumar 3e5a9a6be8 [ubsan] Reduce null checking of C++ object pointers (PR27581)
This patch teaches ubsan to insert exactly one null check for the 'this'
pointer per method/lambda.

Previously, given a load of a member variable from an instance method
('this->x'), ubsan would insert a null check for 'this', and another
null check for '&this->x', before allowing the load to occur.

Similarly, given a call to a method from another method bound to the
same instance ('this->foo()'), ubsan would a redundant null check for
'this'. There is also a redundant null check in the case where the
object pointer is a reference ('Ref.foo()').

This patch teaches ubsan to remove the redundant null checks identified
above.

Testing: check-clang and check-ubsan. I also compiled X86FastISel.cpp
with -fsanitize=null using patched/unpatched clangs based on r293572.
Here are the number of null checks emitted:

  -------------------------------------
  | Setup          | # of null checks |
  -------------------------------------
  | unpatched, -O0 |            21767 |
  | patched, -O0   |            10758 |
  -------------------------------------

Differential Revision: https://reviews.llvm.org/D29530

llvm-svn: 295391
2017-02-17 01:05:42 +00:00
Nick Lewycky 0752762180 When the new expr's array size is an ICE, emit it as a constant expression.
This bypasses integer sanitization checks which are redundant on the expression since it's been checked by Sema. Fixes a clang codegen assertion on "void test() { new int[0+1]{0}; }" when building with -fsanitize=signed-integer-overflow.

llvm-svn: 295006
2017-02-13 23:49:55 +00:00
Richard Smith 30e304e2a6 Remove custom handling of array copies in lambda by-value array capture and
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
2016-12-14 00:03:17 +00:00