Commit Graph

481 Commits

Author SHA1 Message Date
Reid Kleckner 2d3c421f1c Clean up some lambda conversion operator code, NFC
We don't need special handling in CodeGenFunction::GenerateCode for
lambda block pointer conversion operators anymore. The conversion
operator emission code immediately calls back to the generic
EmitFunctionBody.

Rename EmitLambdaStaticInvokeFunction to EmitLambdaStaticInvokeBody for
better consistency with the other Emit*Body methods.

I'm preparing to do something about PR28299, which touches this code.

llvm-svn: 310145
2017-08-04 22:38:06 +00:00
Peter Collingbourne 396943a75b Re-apply r309622 with a fix for MSVC.
Patch by Vlad Tsyrklevich!

llvm-svn: 309635
2017-07-31 22:35:33 +00:00
Peter Collingbourne ab65b0dba1 Revert r309622, "Fix logic for generating llvm.type.test()s"
Caused a bot test failure:
http://bb.pgr.jp/builders/test-clang-msc-x64-on-i686-linux-RA/builds/5325

llvm-svn: 309624
2017-07-31 20:53:16 +00:00
Peter Collingbourne 8867b216dc Fix logic for generating llvm.type.test()s
CodeGenFunction::EmitTypeMetadataCodeForVCall() could output an
llvm.assume(llvm.type.test())when CFI was enabled, optimizing out the
vcall check. This case was only reached when: 1) CFI-vcall was enabled,
2) -fwhole-program-tables was specified, and 3)
-fno-sanitize-trap=cfi-vcall was specified.

Patch by Vlad Tsyrklevich!

Differential Revision: https://reviews.llvm.org/D36013

llvm-svn: 309622
2017-07-31 20:45:14 +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
Sunil Srivastava 15ed292906 Prevent devirtualization of calls to un-instantiated functions.
PR 27895

Differential Revision: https://reviews.llvm.org/D22057

llvm-svn: 305862
2017-06-20 22:08:44 +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
Adrian Prantl b7acfc0139 PR32042: Create inlined debug info for EmitInlinedInheritingCXXConstructorCall.
When clang emits an inheriting C++ constructor it may inline code
during the CodeGen phase. This patch ensures that any debug info in
this inlined code gets a proper inlined location. Otherwise we can end
up with invalid debug info metadata, since all inlined local variables
and function arguments would be reparented into the call site.

Analogous to ApplyInlineLocation this patch introduces a
ApplyInlineDebugLocation scoped helper to facilitate entering an
inlined scope and cleaning up afterwards.

This fixes one of the issues discovered in PR32042.

rdar://problem/30679307

llvm-svn: 296388
2017-02-27 21:30:05 +00:00
Richard Smith df054d3d22 C++ DR1611, 1658, 2180: implement "potentially constructed subobject" rules for special member functions.
Essentially, as a base class constructor does not construct virtual bases, such
a constructor for an abstract class does not need the corresponding base class
construction to be valid, and likewise for destructors.

This creates an awkward situation: clang will sometimes generate references to
the complete object and deleting destructors for an abstract class (it puts
them in the construction vtable for a derived class). But we can't generate a
"correct" version of these because we can't generate references to base class
constructors any more (if they're template specializations, say, we might not
have instantiated them and can't assume any other TU will emit a copy).
Fortunately, we don't need to, since no correct program can ever invoke them,
so instead emit symbols that just trap.

We should stop emitting references to these symbols, but still need to emit
definitions for compatibility.

llvm-svn: 296275
2017-02-25 23:53:05 +00:00
Vedant Kumar 7f809b2fbd [profiling] PR31992: Don't skip interesting non-base constructors
Fix the fact that we don't assign profile counters to constructors in
classes with virtual bases, or constructors with variadic parameters.

Differential Revision: https://reviews.llvm.org/D30131

llvm-svn: 296062
2017-02-24 01:15:19 +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
George Burgess IV f203dbfba9 [CodeGen] Note where we add ABI-specific args in ctors. NFC.
Meta: The ultimate goal is to teach ExtParameterInfo about
pass_object_size attributes. This is necessary for that, since our
ExtParameterInfo is a bit buggy in C++. I plan to actually make use of
this Prefix/Suffix info in the near future, but I like small
single-purpose changes. Especially when those changes are hard to
actually test...

At the moment, some of our C++-specific CodeGen pretends that ABIs can
only add arguments to the beginning of a function call. This isn't quite
correct: args can be appended to the end, as well. It hasn't mattered
much until now, since we seem to only use this "number of arguments
added" data when calculating the ExtParameterInfo to use when making a
CGFunctionInfo. Said ExtParameterInfo is currently only used for
ParameterABIs (Swift) and ns_consumed (ObjC).

So, this patch allows ABIs to indicate whether args they added were at
the beginning or end of an argument list. We can use this information to
emit ExtParameterInfos more correctly, though like said, that bit is
coming soon.

No tests since this is theoretically a nop.

llvm-svn: 295870
2017-02-22 20:28:02 +00:00
Vedant Kumar 18348ea9b9 [ubsan] Pass a set of checks to skip to EmitTypeCheck() (NFC)
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
2017-02-17 23:22:55 +00:00
Warren Ristow 8d17b40500 Prevent ICE in dllexport class with _Atomic data member
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
2017-02-02 17:53:34 +00:00
Saleem Abdulrasool 8de4e87305 CodeGen: add a LLVM_FALLTHROUGH to a fallthrough (NFC)
Drive by cleanup noticed while investigating an IR verifier assertion.

llvm-svn: 293867
2017-02-02 05:45:43 +00:00
Hans Wennborg 27dcc6c0e2 clang-cl: Evaluate arguments left-to-right in constructor call with initializer list (PR31831)
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
2017-02-01 02:21:07 +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
Filipe Cabecinhas 322ecd901b [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

llvm-svn: 289444
2016-12-12 16:18:40 +00:00
Richard Smith a271686ce2 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.

llvm-svn: 286534
2016-11-11 01:01:31 +00:00
Richard Smith 018ac39f94 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.

llvm-svn: 285954
2016-11-03 18:55:18 +00:00
John McCall b92ab1afd5 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.

llvm-svn: 285258
2016-10-26 23:46:34 +00:00
Vedant Kumar 2d38ae6c41 [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

llvm-svn: 284766
2016-10-20 18:44:14 +00:00
John McCall 4c7718d51b 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.

llvm-svn: 276180
2016-07-20 21:02:43 +00:00
Richard Smith 5179eb7821 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

llvm-svn: 274049
2016-06-28 19:03:57 +00:00
Peter Collingbourne 0ca0363d05 CodeGen: Start emitting checked loads when both trapping CFI and -fwhole-program-vtables are enabled.
Differential Revision: http://reviews.llvm.org/D21122

llvm-svn: 273757
2016-06-25 00:24:06 +00:00
Peter Collingbourne 8dd14da0dc CodeGen: Update Clang to use the new type metadata.
Differential Revision: http://reviews.llvm.org/D21054

llvm-svn: 273730
2016-06-24 21:21:46 +00:00
David Majnemer 59f7792136 Use more ArrayRefs
No functional change is intended, just a small refactoring.

llvm-svn: 273647
2016-06-24 04:05:48 +00:00
Alexey Bataev e7545b33ff 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

llvm-svn: 268018
2016-04-29 09:39:50 +00:00
Peter Collingbourne 3afb266886 Re-apply r267784, r267824 and r267830.
I have updated the compiler-rt tests.

llvm-svn: 267903
2016-04-28 17:09:37 +00:00
Benjamin Kramer 5556a5cf3b 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."

llvm-svn: 267871
2016-04-28 12:14:47 +00:00
Peter Collingbourne a8b2f7c0d7 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

llvm-svn: 267784
2016-04-27 20:39:53 +00:00
Richard Smith aa165cf759 [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.

llvm-svn: 266254
2016-04-13 21:57:08 +00:00
Saleem Abdulrasool 10a4972a8d 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.

llvm-svn: 265806
2016-04-08 16:52:00 +00:00
Saleem Abdulrasool 94cfc603d1 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.

llvm-svn: 265702
2016-04-07 17:49:44 +00:00
Peter Collingbourne fb532b9a34 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

llvm-svn: 261767
2016-02-24 20:46:36 +00:00
Eugene Zelenko 0a4f3f4373 Fix some Clang-tidy readability-redundant-control-flow warnings; other minor fixes.
Differential revision: http://reviews.llvm.org/D17060

llvm-svn: 260414
2016-02-10 19:11:58 +00:00
Xinliang David Li a951e8ece7 [PGO] Fix issue: explicitly defaulted assignop is not profiled
Differential Revision: http://reviews.llvm.org/D16947
 

llvm-svn: 260270
2016-02-09 20:02:59 +00:00
Evgeniy Stepanov f31ea30694 [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

llvm-svn: 259716
2016-02-03 22:18:55 +00:00
Eric Christopher d160c50f6b Use a consistent spelling for vtables.
llvm-svn: 259137
2016-01-29 01:35:53 +00:00
Evgeniy Stepanov 3fd61df186 [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.

llvm-svn: 258745
2016-01-25 23:34:52 +00:00
Peter Collingbourne dc13453128 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

llvm-svn: 257971
2016-01-16 00:31:22 +00:00
Evgeniy Stepanov fd6f92d5cb 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.

llvm-svn: 255694
2015-12-15 23:00:20 +00:00
Hans Wennborg dcfba33481 Fix Clang-tidy modernize-use-nullptr warnings in source directories; other minor cleanups
Patch by Eugene Zelenko!

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

llvm-svn: 249484
2015-10-06 23:40:43 +00:00
Piotr Padlewski 276a78d860 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

llvm-svn: 249197
2015-10-02 22:12:40 +00:00
Piotr Padlewski 69dc971527 Generate assume loads only with -fstrict-vtable-pointers
Temporary fix till InstCombine and other possible passes will be
efficient to handle multiple assumes.

llvm-svn: 248734
2015-09-28 20:30:22 +00:00
NAKAMURA Takumi ee82b497f8 CGClass.cpp: Fix a warning in -Asserts. [-Wunused-private-field]
llvm-svn: 247778
2015-09-16 06:26:56 +00:00
Naomi Musgrave 703835c7f3 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.

llvm-svn: 247762
2015-09-16 00:38:22 +00:00
Piotr Padlewski 4b1ac72cd4 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

llvm-svn: 247725
2015-09-15 21:46:55 +00:00
Piotr Padlewski 338c9d0ade 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

llvm-svn: 247723
2015-09-15 21:46:47 +00:00
Piotr Padlewski d679d7e924 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

llvm-svn: 247646
2015-09-15 00:37:06 +00:00
Evgeniy Stepanov 6b2a61d3a5 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.

llvm-svn: 247620
2015-09-14 21:35:16 +00:00
Evgeniy Stepanov 93db40a147 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.

llvm-svn: 247494
2015-09-12 01:07:37 +00:00
Evgeniy Stepanov 67037ee21e Revert "Specify target triple in alwaysinline tests."
Revert "Always_inline codegen rewrite."

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

llvm-svn: 247491
2015-09-11 23:48:37 +00:00
Evgeniy Stepanov 072e83500e 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.

llvm-svn: 247465
2015-09-11 20:29:07 +00:00
Piotr Padlewski 4bed31b9bf 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 982bb7d966947812d216489b3c519c9825cacbf2.

llvm-svn: 247332
2015-09-10 20:18:30 +00:00
Peter Collingbourne 2c7f7e31c4 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

llvm-svn: 247238
2015-09-10 02:17:40 +00:00
Piotr Padlewski 255652e828 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

llvm-svn: 247199
2015-09-09 22:20:28 +00:00
NAKAMURA Takumi ff7a9252e8 clangCodeGen: Fix comments. [-Wdocumentation]
llvm-svn: 246995
2015-09-08 09:42:41 +00:00
John McCall 7f416cc426 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.

llvm-svn: 246985
2015-09-08 08:05:57 +00:00
NAKAMURA Takumi f6cef72f12 Fix a couple of \param(s) in r246815. [-Wdocumentation]
llvm-svn: 246838
2015-09-04 05:19:31 +00:00
Naomi Musgrave 866af2d6d1 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.

llvm-svn: 246815
2015-09-03 23:02:30 +00:00
Steven Wu 5528da76ef Revert r246214 and r246213
These two commits causes llvm LTO bootstrap to hang in ScalarEvolution.

llvm-svn: 246282
2015-08-28 07:14:10 +00:00
Piotr Padlewski 81461a4350 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

llvm-svn: 246214
2015-08-27 21:35:41 +00:00
Piotr Padlewski 525f746710 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

llvm-svn: 246213
2015-08-27 21:35:37 +00:00
Piotr Padlewski fa0e11efdd Revert "Generating assumption loads of vptr after ctor call (fixed)"
Reverting because of 245721

This reverts commit 552658e2b60543c928030b09cc9b5dfcb40c3f28.

llvm-svn: 245727
2015-08-21 19:49:41 +00:00
Piotr Padlewski 910a059e42 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

llvm-svn: 245721
2015-08-21 18:28:00 +00:00
David Blaikie 7e70d6803d Devirtualize EHScopeStack::Cleanup's dtor because it's never destroyed polymorphically
llvm-svn: 245378
2015-08-18 22:40:54 +00:00
Justin Bogner 3c32c83daa Revert "Generating assumption loads of vptr after ctor call (fixed)"
Bootstrap bots were failing:

http://lab.llvm.org:8080/green/job/clang-stage2-configure-Rlto_build/6382/
http://bb.pgr.jp/builders/clang-3stage-i686-linux/builds/2969

This reverts r245264.

llvm-svn: 245267
2015-08-18 05:40:20 +00:00
Piotr Padlewski bc7497abbb 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

llvm-svn: 245264
2015-08-18 03:52:00 +00:00
Hans Wennborg 386e442d1d Revert r245257 "Generating assumption loads of vptr after ctor call"
It caused PR24479

llvm-svn: 245260
2015-08-18 00:17:58 +00:00
Piotr Padlewski a3f6f9477b Generating assumption loads of vptr after ctor call
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

http://reviews.llvm.org/D11859

llvm-svn: 245257
2015-08-17 23:33:49 +00:00
Naomi Musgrave e50cb9b9c8 Fix previous commit: poison only class members, simpler tests
Summary: Poisoning applied to only class members, and before dtors for base class invoked

Implement poisoning of only class members in dtor, as opposed to also
poisoning fields inherited from base classes. Members are poisoned
only once, by the last dtor for a class. Skip poisoning if class has
no fields.
Verify emitted code for derived class with virtual destructor sanitizes
its members only once.
Removed patch file containing extraneous changes.

Reviewers: eugenis, kcc

Differential Revision: http://reviews.llvm.org/D11951


Simplified test cases for use-after-dtor

Summary: Simplified test cases to focus on one feature at time.
Tests updated to align with new emission order for sanitizing
callback.

Reviewers: eugenis, kcc

Differential Revision: http://reviews.llvm.org/D12003

llvm-svn: 244933
2015-08-13 18:35:11 +00:00
Naomi Musgrave 522168f7b8 Revert "Implement poisoning of only class members in dtor, as opposed to also poisoning fields inherited from base classes."
This reverts commit 8dbbf3578a9a5d063232b59e558e5fe46e2cd42c.
Rolled back due to buildbot failures on 'ninja check-clang'.

llvm-svn: 244820
2015-08-12 22:07:24 +00:00
Naomi Musgrave 9bd83fd465 Implement poisoning of only class members in dtor, as opposed to also poisoning fields inherited from base classes.
Verify emitted code for derived class with virtual destructor sanitizes its members only once.
Changed emission order for dtor callback, so only the last dtor for a class emits the sanitizing callback, while ensuring that class members are poisoned before base class destructors are invoked.
Skip poisoning of members, if class has no fields.
Removed patch file containing extraneous changes.

Summary: Poisoning applied to only class members, and before dtors for base class invoked

Reviewers: eugenis, kcc

Differential Revision: http://reviews.llvm.org/D11951

llvm-svn: 244819
2015-08-12 21:37:40 +00:00
Naomi Musgrave bb4df94faa Dtor callback emitted when msan attribute not repressed for this function.
Summary: In addition to checking compiler flags, the front-end also examines the attributes of the destructor definition to ensure that the SanitizeMemory attribute is attached.

Reviewers: eugenis, kcc

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D11727

refactored test into new file, revised how function attribute examined

modified test to examine default dtor with and without attribute

removed attribute check

llvm-svn: 243912
2015-08-03 22:53:11 +00:00
Naomi Musgrave 5c79fb72fa Updated test regex and flags
llvm-svn: 243669
2015-07-30 17:59:48 +00:00
Naomi Musgrave 21792b145d repress tail call optimization when performing use-after-dtor sanitization
Reviewers: eugenis, kcc

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D11613

llvm-svn: 243668
2015-07-30 17:59:46 +00:00
David Blaikie f05779e21c Pass an iterator range to EmitCallArgs
llvm-svn: 242824
2015-07-21 18:37:18 +00:00
Benjamin Kramer f48ee4482a [AST] Cleanup ExprIterator.
- Make it a proper random access iterator with a little help from iterator_adaptor_base
- Clean up users of magic dereferencing. The iterator should behave like an Expr **.
- Make it an implementation detail of Stmt. This allows inlining of the assertions.

llvm-svn: 242608
2015-07-18 14:35:53 +00:00
Peter Collingbourne 6fccf95aad CodeGen: Improve CFI type blacklisting mechanism.
We now use the sanitizer special case list to decide which types to blacklist.
We also support a special blacklist entry for types with a uuid attribute,
which are generally COM types whose virtual tables are defined externally.

Differential Revision: http://reviews.llvm.org/D11096

llvm-svn: 242286
2015-07-15 12:15:56 +00:00
Alexey Bataev 152c71f3af Fix for clang memcpyizer bugs 23911 and 23924 (patch by Denis Zobnin)
The fix is to remove duplicate copy-initialization of the only memcpy-able struct member and to correct the address of aggregately initialized members in destructors' calls during stack unwinding (in order to obtain address of struct member by using GEP instead of 'bitcast').
Differential Revision: http://reviews.llvm.org/D10990

llvm-svn: 242127
2015-07-14 07:55:48 +00:00
Evgeniy Stepanov 7cacbe4d9e Basic code generation for MSan use-after-dtor.
Under the -fsanitize-memory-use-after-dtor (disabled by default) insert
an MSan runtime library call at the end of every destructor.

Patch by Naomi Musgrave.

llvm-svn: 242097
2015-07-14 00:34:50 +00:00
Ulrich Weigand 73263d72d3 Update comment
As noticed by David Majnemer, update an out-of-date comment in
CGClass.cpp after the r241916 commit.

llvm-svn: 242021
2015-07-13 11:52:14 +00:00
Ulrich Weigand 03ce2a16bf Respect alignment of nested bitfields
tools/clang/test/CodeGen/packed-nest-unpacked.c contains this test:

struct XBitfield {
  unsigned b1 : 10;
  unsigned b2 : 12;
  unsigned b3 : 10;
};
struct YBitfield {
  char x;
  struct XBitfield y;
} __attribute((packed));
struct YBitfield gbitfield;

unsigned test7() {
  // CHECK: @test7
  // CHECK: load i32, i32* getelementptr inbounds (%struct.YBitfield, %struct.YBitfield* @gbitfield, i32 0, i32 1, i32 0), align 4
  return gbitfield.y.b2;
}

The "align 4" is actually wrong.  Accessing all of "gbitfield.y" as a single
i32 is of course possible, but that still doesn't make it 4-byte aligned as
it remains packed at offset 1 in the surrounding gbitfield object.

This alignment was changed by commit r169489, which also introduced changes
to bitfield access code in CGExpr.cpp.  Code before that change used to take
into account *both* the alignment of the field to be accessed within the
current struct, *and* the alignment of that outer struct itself; this logic
was removed by the above commit.

Neglecting to consider both values can cause incorrect code to be generated
(I've seen an unaligned access crash on SystemZ due to this bug).

In order to always use the best known alignment value, this patch removes
the CGBitFieldInfo::StorageAlignment member and replaces it with a
StorageOffset member specifying the offset from the start of the surrounding
struct to the bitfield's underlying storage.  This offset can then be combined
with the best-known alignment for a bitfield access lvalue to determine the
alignment to use when accessing the bitfield's storage.

Differential Revision: http://reviews.llvm.org/D11034

llvm-svn: 241916
2015-07-10 17:30:00 +00:00
Peter Collingbourne e570644285 CFI: Emit correct bit set information if RTTI is disabled under MS ABI.
We were previously creating bit set entries at virtual table offset
sizeof(void*) unconditionally under the Microsoft C++ ABI. This is incorrect
if RTTI data is disabled; in that case the "address point" is at offset
0. This change modifies bit set emission to take into account whether RTTI
data is being emitted.

Also make a start on a blacklisting scheme for records.

Differential Revision: http://reviews.llvm.org/D11048

llvm-svn: 241845
2015-07-09 19:56:14 +00:00
Alexey Bataev 5d49b83020 [EH] Fix for clang bug 24005 - no cleanup for array of memcpy-able objects in struct (patch by Denis Zobnin)
The fix is to emit cleanup for arrays of memcpy-able objects in struct if an exception is thrown later during copy-construction.
Differential Revision: http://reviews.llvm.org/D10989

llvm-svn: 241670
2015-07-08 07:31:02 +00:00
Davide Italiano 982bbf404e [Sema] Commit a better fix for r240242
Skip calls to HasTrivialDestructorBody() in the case where the
destructor is never invoked. Alternatively, Richard proposed to change
Sema to declare a trivial destructor for anonymous union member, which
seems too wasteful.

Differential Revision:	http://reviews.llvm.org/D10508

llvm-svn: 240742
2015-06-26 00:18:35 +00:00
David Majnemer c1709d387e [MS ABI] Rework member pointer conversion
Member pointers in the MS ABI are made complicated due to the following:
- Virtual methods in the most derived class (MDC) might live in a
  vftable in a virtual base.
- There are four different representations of member pointer: single
  inheritance, multiple inheritance, virtual inheritance and the "most
  general" representation.
- Bases might have a *more* general representation than classes which
  derived from them, a most surprising result.

We believed that we could treat all member pointers as-if they were a
degenerate case of the multiple inheritance model.  This fell apart once
we realized that implementing standard member pointers using this ABI
requires referencing members with a non-zero vbindex.

On a bright note, all but the virtual inheritance model operate rather
similarly.  The virtual inheritance member pointer representation
awkwardly requires a virtual base adjustment in order to refer to
entities in the MDC.

However, the first virtual base might be quite far from the start of the
virtual base.  This means that we must add a negative non-virtual
displacement.

However, things get even more complicated.  The most general
representation interprets vbindex zero differently from the virtual
inheritance model: it doesn't reference the vbtable at all.

It turns out that this complexity can increase for quite some time:
consider a derived to base conversion from the most general model to the
multiple inheritance model...

To manage this complexity we introduce a concept of "normalized" member
pointer which allows us to treat all three models as the most general
model.  Then we try to figure out how to map this generalized member
pointer onto the destination member pointer model.  I've done my best to
furnish the code with comments explaining why each adjustment is
performed.

This fixes PR23878.

llvm-svn: 240384
2015-06-23 07:31:11 +00:00
Alexander Kornienko ab9db51042 Revert r240270 ("Fixed/added namespace ending comments using clang-tidy").
llvm-svn: 240353
2015-06-22 23:07:51 +00:00
Alexander Kornienko 3d9d929e42 Fixed/added namespace ending comments using clang-tidy. NFC
The patch is generated using this command:

  $ tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
      -checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
      work/llvm/tools/clang

To reduce churn, not touching namespaces spanning less than 10 lines.

llvm-svn: 240270
2015-06-22 09:47:44 +00:00
Davide Italiano 8c93d5eddc [Codegen] Don't crash if destructor is not accessible.
Testcase provided, in the PR, by Christian Shelton and
reduced by David Majnemer.

PR:		23584
Differential Revision:	http://reviews.llvm.org/D10508
Reviewed by:	rnk

llvm-svn: 240242
2015-06-21 16:33:50 +00:00
Peter Collingbourne 6708c4a176 Implement diagnostic mode for -fsanitize=cfi*, -fsanitize=cfi-diag.
This causes programs compiled with this flag to print a diagnostic when
a control flow integrity check fails instead of aborting. Diagnostics are
printed using UBSan's runtime library.

The main motivation of this feature over -fsanitize=vptr is fidelity with
the -fsanitize=cfi implementation: the diagnostics are printed under exactly
the same conditions as those which would cause -fsanitize=cfi to abort the
program. This means that the same restrictions apply regarding compiling
all translation units with -fsanitize=cfi, cross-DSO virtual calls are
forbidden, etc.

Differential Revision: http://reviews.llvm.org/D10268

llvm-svn: 240109
2015-06-19 01:51:54 +00:00
Scott Douglass 503fc39d1f add ConstEvaluatedExprVisitor
Differential Revision: http://reviews.llvm.org/D10210

llvm-svn: 239474
2015-06-10 13:53:15 +00:00
Justin Bogner fb29822bf4 InstrProf: Increment the profile counter for all types of destructor
-fprofile-instr-generate does not emit counter increment intrinsics
for Dtor_Deleting and Dtor_Complete destructors with assigned
counters. This causes unnecessary [-Wprofile-instr-out-of-date]
warnings during profile-use runs even if the source has never been
modified since profile collection.

Patch by Betul Buyukkurt. Thanks!

llvm-svn: 237804
2015-05-20 16:16:23 +00:00
Justin Bogner 1cd11f159e CodeGen: Remove some trailing whitespace. NFC
llvm-svn: 237802
2015-05-20 15:53:59 +00:00
David Blaikie 43f9bb7371 API update for streamlining of IRBuilder::CreateCall to just use ArrayRef/initializer_list+braced init
llvm-svn: 237625
2015-05-18 22:14:03 +00:00
Richard Smith 419bd09415 PR23373: A defaulted union copy constructor that is not trivial must still be
emitted as a memcpy.

llvm-svn: 236142
2015-04-29 19:26:57 +00:00
Justin Bogner 66242d6c5e InstrProf: Stop using RegionCounter outside of CodeGenPGO (NFC)
The RegionCounter type does a lot of legwork, but most of it is only
meaningful within the implementation of CodeGenPGO. The uses elsewhere
in CodeGen generally just want to increment or read counters, so do
that directly.

llvm-svn: 235664
2015-04-23 23:06:47 +00:00
Peter Collingbourne 1a7488afaa Implement CFI type checks for non-virtual calls.
This uses the same class metadata currently used for virtual call and
cast checks.

The new flag is -fsanitize=cfi-nvcall. For consistency, the -fsanitize=cfi-vptr
flag has been renamed -fsanitize=cfi-vcall.

Differential Revision: http://reviews.llvm.org/D8756

llvm-svn: 233874
2015-04-02 00:23:30 +00:00
Peter Collingbourne d2926c91d5 Implement bad cast checks using control flow integrity information.
This scheme checks that pointer and lvalue casts are made to an object of
the correct dynamic type; that is, the dynamic type of the object must be
a derived class of the pointee type of the cast. The checks are currently
only introduced where the class being casted to is a polymorphic class.

Differential Revision: http://reviews.llvm.org/D8312

llvm-svn: 232241
2015-03-14 02:42:25 +00:00