Commit Graph

415 Commits

Author SHA1 Message Date
Richard Smith 993e3aa6b9 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.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@289618 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-14 00:03:17 +00:00
Filipe Cabecinhas 19350fe26f [clang] Version support for UBSan handlers
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

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@289444 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-12 16:18:40 +00:00
Richard Smith 4f7770e365 PR30937: don't devirtualize if we find that the callee is a pure virtual
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.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@286534 91177308-0d34-0410-b5e6-96231b3b80d8
2016-11-11 01:01:31 +00:00
Richard Smith 4d47937a53 Improve obvious-most-derived-type devirtualization:
* 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.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@285954 91177308-0d34-0410-b5e6-96231b3b80d8
2016-11-03 18:55:18 +00:00
John McCall a896e9a7d2 Refactor call emission to package the function pointer together with
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.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@285258 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-26 23:46:34 +00:00
Vedant Kumar 149b77526e [CodeGen] Devirtualize calls to methods marked final in a derived class
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

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@284766 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-20 18:44:14 +00:00
John McCall dbfd55f5ba When copying an array into a lambda, destroy temporaries from
the copy-constructor immediately and enter a partial array
cleanup for previously-copied elements.

Fixes PR28595.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@276180 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-20 21:02:43 +00:00
Richard Smith 5be817d9f9 P0136R1, DR1573, DR1645, DR1715, DR1736, DR1903, DR1941, DR1959, DR1991:
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


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@274049 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-28 19:03:57 +00:00
Peter Collingbourne 8253227d6c CodeGen: Start emitting checked loads when both trapping CFI and -fwhole-program-vtables are enabled.
Differential Revision: http://reviews.llvm.org/D21122

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@273757 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-25 00:24:06 +00:00
Peter Collingbourne 3400678c4b CodeGen: Update Clang to use the new type metadata.
Differential Revision: http://reviews.llvm.org/D21054

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@273730 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-24 21:21:46 +00:00
David Majnemer ba5c7ce848 Use more ArrayRefs
No functional change is intended, just a small refactoring.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@273647 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-24 04:05:48 +00:00
Alexey Bataev 0e2d28ae3b Implementation of VlA of GNU C++ extension, by Vladimir Yakovlev.
This enables GNU C++ extension "Variable length array" by default.
Differential Revision: http://reviews.llvm.org/D18823

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@268018 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-29 09:39:50 +00:00
Peter Collingbourne 5b0d0a6495 Re-apply r267784, r267824 and r267830.
I have updated the compiler-rt tests.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@267903 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-28 17:09:37 +00:00
Benjamin Kramer ce850d4bf5 Revert r267784, r267824 and r267830.
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."

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@267871 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-28 12:14:47 +00:00
Peter Collingbourne 47213cf975 Rework interface for bitset-using features to use a notion of LTO visibility.
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

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@267784 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-27 20:39:53 +00:00
Richard Smith 7341605a7a [modules] Remove CXX_CTOR_INITIALIZERS_OFFSETS table. Instead of storing an ID
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.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@266254 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-13 21:57:08 +00:00
Saleem Abdulrasool fdc51a5580 revert SVN r265702, r265640
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.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@265806 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-08 16:52:00 +00:00
Saleem Abdulrasool 8cca4d7cdf Basic: move CodeGenOptions from Frontend
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.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@265702 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-07 17:49:44 +00:00
Peter Collingbourne 209acc3e3d Add whole-program vtable optimization feature to Clang.
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

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@261767 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-24 20:46:36 +00:00
Eugene Zelenko b9b46f780d Fix some Clang-tidy readability-redundant-control-flow warnings; other minor fixes.
Differential revision: http://reviews.llvm.org/D17060


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@260414 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-10 19:11:58 +00:00
Xinliang David Li 424e3d7732 [PGO] Fix issue: explicitly defaulted assignop is not profiled
Differential Revision: http://reviews.llvm.org/D16947
 





git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@260270 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-09 20:02:59 +00:00
Evgeniy Stepanov 388a054401 [cfi] Safe handling of unaddressable vtable pointers (clang).
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

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@259716 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-03 22:18:55 +00:00
Eric Christopher eae9579a01 Use a consistent spelling for vtables.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@259137 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-29 01:35:53 +00:00
Evgeniy Stepanov 186629894f [cfi] Cross-DSO CFI diagnostic mode (clang part)
* 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.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@258745 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-25 23:34:52 +00:00
Peter Collingbourne f2ac4da6f7 Introduce -fsanitize-stats flag.
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

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@257971 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-16 00:31:22 +00:00
Evgeniy Stepanov 3a8ad7e2f6 Cross-DSO control flow integrity (Clang part).
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.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@255694 91177308-0d34-0410-b5e6-96231b3b80d8
2015-12-15 23:00:20 +00:00
Hans Wennborg 94faed6137 Fix Clang-tidy modernize-use-nullptr warnings in source directories; other minor cleanups
Patch by Eugene Zelenko!

Differential Revision: http://reviews.llvm.org/D13406

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@249484 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-06 23:40:43 +00:00
Piotr Padlewski b616928f43 Emiting invariant.group.barrier for ctors bugfix
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

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@249197 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-02 22:12:40 +00:00
Piotr Padlewski bfa22743ff Generate assume loads only with -fstrict-vtable-pointers
Temporary fix till InstCombine and other possible passes will be
efficient to handle multiple assumes.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@248734 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-28 20:30:22 +00:00
NAKAMURA Takumi 142875b39b CGClass.cpp: Fix a warning in -Asserts. [-Wunused-private-field]
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@247778 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-16 06:26:56 +00:00
Naomi Musgrave de170619af Implementation and testing for poisoning vtable
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.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@247762 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-16 00:38:22 +00:00
Piotr Padlewski 3a91316f3b Decorating vptr load & stores with !invariant.group
Adding !invariant.group to vptr load/stores for devirtualization purposes.
For more goto:
http://lists.llvm.org/pipermail/cfe-dev/2015-July/044227.html

http://reviews.llvm.org/D12026

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@247725 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-15 21:46:55 +00:00
Piotr Padlewski ac87852f57 Emiting llvm.invariant.group.barrier when dynamic type changes
For more goto:
http://lists.llvm.org/pipermail/cfe-dev/2015-July/044227.html

http://reviews.llvm.org/D12312

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@247723 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-15 21:46:47 +00:00
Piotr Padlewski 81654dc1dd Generating assumption loads of vptr after ctor call (fixed)
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 and other bug caused in chrome.
After this patch got reverted because of ScalarEvolution bug (D12719)
Merged after John McCall big patch (Added Address).

http://reviews.llvm.org/D11859
http://reviews.llvm.org/D12865

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@247646 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-15 00:37:06 +00:00
Evgeniy Stepanov 0ed34fe7f0 Revert "Always_inline codegen rewrite" and 2 follow-ups.
Revert "Update cxx-irgen.cpp test to allow signext in alwaysinline functions."
Revert "[CodeGen] Remove wrapper-free always_inline functions from COMDATs"
Revert "Always_inline codegen rewrite."

Reason for revert: PR24793.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@247620 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-14 21:35:16 +00:00
Evgeniy Stepanov b41a71b123 Always_inline codegen rewrite.
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.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@247494 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-12 01:07:37 +00:00
Evgeniy Stepanov b9dc14a84e Revert "Specify target triple in alwaysinline tests."
Revert "Always_inline codegen rewrite."

Breaks gdb & lldb tests.
Breaks on Fedora 22 x86_64.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@247491 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-11 23:48:37 +00:00
Evgeniy Stepanov bfffdd3dff Always_inline codegen rewrite.
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.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@247465 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-11 20:29:07 +00:00
Piotr Padlewski 2d836afad9 Revert "Generating assumption loads of vptr after ctor call (fixed)"
It seems that there is small bug, and we can't generate assume loads
when some virtual functions have internal visibiliy
This reverts commit 982bb7d966.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@247332 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-10 20:18:30 +00:00
Peter Collingbourne f29b6351df CFI: Introduce -fsanitize=cfi-icall flag.
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

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@247238 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-10 02:17:40 +00:00
Piotr Padlewski 982bb7d966 Generating assumption loads of vptr after ctor call (fixed)
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

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@247199 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-09 22:20:28 +00:00
NAKAMURA Takumi 7d83f25a86 clangCodeGen: Fix comments. [-Wdocumentation]
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@246995 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-08 09:42:41 +00:00
John McCall f4ddf94ecb Compute and preserve alignment more faithfully in IR-generation.
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.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@246985 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-08 08:05:57 +00:00
NAKAMURA Takumi e5c8886540 Fix a couple of \param(s) in r246815. [-Wdocumentation]
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@246838 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-04 05:19:31 +00:00
Naomi Musgrave 8508b90429 Refactored dtor sanitizing into EHScopeStack
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.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@246815 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-03 23:02:30 +00:00
Steven Wu 85b5116ba2 Revert r246214 and r246213
These two commits causes llvm LTO bootstrap to hang in ScalarEvolution.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@246282 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-28 07:14:10 +00:00
Piotr Padlewski 3e3b23e283 Assume loads fix #2
There was linker problem, and it turns out that it is not always safe
to refer to vtable. If the vtable is used, then we can refer to it
without any problem, but because we don't know when it will be used or
not, we can only check if vtable is external or it is safe to to emit it
speculativly (when class it doesn't have any inline virtual functions).
It should be fixed in the future.

http://reviews.llvm.org/D12385

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@246214 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-27 21:35:41 +00:00
Piotr Padlewski b50aff8739 Generating assumption loads of vptr after ctor call (fixed)
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.

http://reviews.llvm.org/D11859

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@246213 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-27 21:35:37 +00:00
Piotr Padlewski 11767c398a Revert "Generating assumption loads of vptr after ctor call (fixed)"
Reverting because of 245721

This reverts commit 552658e2b6.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@245727 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-21 19:49:41 +00:00
Piotr Padlewski 552658e2b6 Generating assumption loads of vptr after ctor call (fixed)
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.

http://reviews.llvm.org/D11859

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@245721 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-21 18:28:00 +00:00