Commit Graph

415 Commits

Author SHA1 Message Date
Richard Smith 00223827a9 Improve code generation for thread_local variables:
Summary:
 * Don't bother using a thread wrapper when the variable is known to
   have constant initialization.
 * Emit the thread wrapper as discardable-if-unused in TUs that don't
   contain a definition of the thread_local variable.
 * Don't emit the thread wrapper at all if the thread_local variable
   is unused and discardable; it will be emitted by all TUs that need
   it.

Reviewers: rjmccall, jdoerfert

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D67429

llvm-svn: 371767
2019-09-12 20:00:24 +00:00
Marco Antognini 8855963764 [OpenCL] Improve destructor support in C++ for OpenCL
This re-applies r366422 with a fix for Bug PR42665 and a new regression
test.

llvm-svn: 366670
2019-07-22 09:39:13 +00:00
Ilya Biryukov 4f8dc16fcd Revert r366422: [OpenCL] Improve destructor support in C++ for OpenCL
Reason: this commit causes crashes in the clang compiler when building
LLVM Support with libc++, see https://bugs.llvm.org/show_bug.cgi?id=42665
for details.

llvm-svn: 366429
2019-07-18 11:55:33 +00:00
Marco Antognini 83748cc5ab [OpenCL] Improve destructor support in C++ for OpenCL
Summary:
This patch does mainly three things:
 1. It fixes a false positive error detection in Sema that is similar to
    D62156. The error happens when explicitly calling an overloaded
    destructor for different address spaces.
 2. It selects the correct destructor when multiple overloads for
    address spaces are available.
 3. It inserts the expected address space cast when invoking a
    destructor, if needed, and therefore fixes a crash due to the unmet
    assertion in llvm::CastInst::Create.

The following is a reproducer of the three issues:

    struct MyType {
      ~MyType() {}
      ~MyType() __constant {}
    };

    __constant MyType myGlobal{};

    kernel void foo() {
      myGlobal.~MyType(); // 1 and 2.
      // 1. error: cannot initialize object parameter of type
      //    '__generic MyType' with an expression of type '__constant MyType'
      // 2. error: no matching member function for call to '~MyType'
    }

    kernel void bar() {
      // 3. The implicit call to the destructor crashes due to:
      //    Assertion `castIsValid(op, S, Ty) && "Invalid cast!"' failed.
      //    in llvm::CastInst::Create.
      MyType myLocal;
    }

The added test depends on D62413 and covers a few more things than the
above reproducer.

Subscribers: yaxunl, Anastasia, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D64569

llvm-svn: 366422
2019-07-18 10:04:18 +00:00
Rui Ueyama 49a3ad21d6 Fix parameter name comments using clang-tidy. NFC.
This patch applies clang-tidy's bugprone-argument-comment tool
to LLVM, clang and lld source trees. Here is how I created this
patch:

$ git clone https://github.com/llvm/llvm-project.git
$ cd llvm-project
$ mkdir build
$ cd build
$ cmake -GNinja -DCMAKE_BUILD_TYPE=Debug \
    -DLLVM_ENABLE_PROJECTS='clang;lld;clang-tools-extra' \
    -DCMAKE_EXPORT_COMPILE_COMMANDS=On -DLLVM_ENABLE_LLD=On \
    -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ ../llvm
$ ninja
$ parallel clang-tidy -checks='-*,bugprone-argument-comment' \
    -config='{CheckOptions: [{key: StrictMode, value: 1}]}' -fix \
    ::: ../llvm/lib/**/*.{cpp,h} ../clang/lib/**/*.{cpp,h} ../lld/**/*.{cpp,h}

llvm-svn: 366177
2019-07-16 04:46:31 +00:00
Mandeep Singh Grang 85a0f8fe6c [COFF, ARM64] Fix ABI implementation of struct returns
Summary:
Related llvm patch: D60348.
Patch co-authored by Sanjin Sijaric.

Reviewers: rnk, efriedma, TomTan, ssijaric, ostannard

Reviewed By: efriedma

Subscribers: dmajor, richard.townsend.arm, ostannard, javed.absar, kristof.beyls, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D60349

llvm-svn: 359932
2019-05-03 21:12:24 +00:00
Reid Kleckner adb419897c Remove two unnecessary wrappers of canPassInRegisters
These extra layers aren't necessary.

llvm-svn: 359623
2019-04-30 22:23:20 +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
Don Hinton f170dff3c1 Refactor cast<>'s in if conditionals, which can only assert on failure.
Summary:
This patch refactors several instances of cast<> used in if
conditionals.  Since cast<> asserts on failure, the else branch can
never be taken.

In some cases, the fix is to replace cast<> with dyn_cast<>.  While
others required the removal of the conditional and some minor
refactoring.

A discussion can be seen here: http://lists.llvm.org/pipermail/cfe-commits/Week-of-Mon-20190318/265044.html

Differential Revision: https://reviews.llvm.org/D59529

llvm-svn: 356441
2019-03-19 06:14:14 +00:00
James Y Knight f7321540d5 [opaque pointer types] Pass through function types for TLS
initialization and global destructor calls.

Differential Revision: https://reviews.llvm.org/D57801

llvm-svn: 353355
2019-02-07 01:14:17 +00:00
James Y Knight 76f787424d [opaque pointer types] More trivial changes to pass FunctionType to CallInst.
Change various functions to use FunctionCallee or Function*.

Pass function type through __builtin_dump_struct's dumpRecord helper.

llvm-svn: 353199
2019-02-05 19:17:50 +00:00
James Y Knight 9871db064d [opaque pointer types] Pass function types for runtime function calls.
Emit{Nounwind,}RuntimeCall{,OrInvoke} have been modified to take a
FunctionCallee as an argument, and CreateRuntimeFunction has been
modified to return a FunctionCallee. All callers have been updated.

Additionally, CreateBuiltinFunction is removed, as it was redundant
with CreateRuntimeFunction after some previous changes.

Differential Revision: https://reviews.llvm.org/D57668

llvm-svn: 353184
2019-02-05 16:42:33 +00:00
James Y Knight 3933addd30 Cleanup: replace uses of CallSite with CallBase.
llvm-svn: 352595
2019-01-30 02:54:28 +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
Brian Gesiak 5488ab4ddd [AST] Remove ASTContext from getThisType (NFC)
Summary:
https://reviews.llvm.org/D54862 removed the usages of `ASTContext&` from
within the `CXXMethodDecl::getThisType` method. Remove the parameter
altogether, as well as all usages of it. This does not result in any
functional change because the parameter was unused since
https://reviews.llvm.org/D54862.

Test Plan: check-clang

Reviewers: akyrtzi, mikael

Reviewed By: mikael

Subscribers: mehdi_amini, dexonsmith, cfe-commits

Differential Revision: https://reviews.llvm.org/D56509

llvm-svn: 350914
2019-01-11 01:54:53 +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
David Green be0c5b6d3c [CodeGen] Align rtti and vtable data
Previously the alignment on the newly created rtti/typeinfo data was largely
not set, meaning that DataLayout::getPreferredAlignment was free to overalign
it to 16 bytes. This causes unnecessary code bloat.

Differential Revision: https://reviews.llvm.org/D51416

llvm-svn: 342053
2018-09-12 14:09:06 +00:00
Erik Pilkington 5a559e64a9 Add a new flag and attributes to control static destructor registration
This commit adds the flag -fno-c++-static-destructors and the attributes
[[clang::no_destroy]] and [[clang::always_destroy]]. no_destroy specifies that a
specific static or thread duration variable shouldn't have it's destructor
registered, and is the default in -fno-c++-static-destructors mode.
always_destroy is the opposite, and is the default in -fc++-static-destructors
mode.

A variable whose destructor is disabled (either because of
-fno-c++-static-destructors or [[clang::no_destroy]]) doesn't count as a use of
the destructor, so we don't do any access checking or mark it referenced. We
also don't emit -Wexit-time-destructors for these variables.

rdar://21734598

Differential revision: https://reviews.llvm.org/D50994

llvm-svn: 340306
2018-08-21 17:24:06 +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
Sanjin Sijaric 56391d6f84 [ARM64] [Windows] Follow MS X86_64 C++ ABI when passing structs
Summary: Microsoft's C++ object model for ARM64 is the same as that for X86_64.
For example, small structs with non-trivial copy constructors or virtual
function tables are passed indirectly.  Currently, they are passed in registers
when compiled with clang.

Reviewers: rnk, mstorsjo, TomTan, haripul, javed.absar

Reviewed By: rnk, mstorsjo

Subscribers: kristof.beyls, chrib, llvm-commits, cfe-commits

Differential Revision: https://reviews.llvm.org/D49770

llvm-svn: 338076
2018-07-26 22:18:28 +00:00
Mandeep Singh Grang 2a153101bf [COFF, ARM64] Decide when to mark struct returns as SRet
Summary:
Refer the MS ARM64 ABI Convention for the behavior for struct returns:
https://docs.microsoft.com/en-us/cpp/build/arm64-windows-abi-conventions#return-values

Reviewers: mstorsjo, compnerd, rnk, javed.absar, yinma, efriedma

Reviewed By: rnk, efriedma

Subscribers: haripul, TomTan, yinma, efriedma, kristof.beyls, chrib, llvm-commits

Differential Revision: https://reviews.llvm.org/D49464

llvm-svn: 338050
2018-07-26 18:07:59 +00:00
Nico Weber f29044536d fix typo in comment
llvm-svn: 337480
2018-07-19 18:59:38 +00:00
Heejin Ahn c647919933 [WebAssembly] Use Windows EH instructions for Wasm EH
Summary:
Because wasm control flow needs to be structured, using WinEH
instructions to support wasm EH brings several benefits. This patch
makes wasm EH uses Windows EH instructions, with some changes:
1. Because wasm uses a single catch block to catch all C++ exceptions,
   this merges all catch clauses into a single catchpad, within which we
   test the EH selector as in Itanium EH.
2. Generates a call to `__clang_call_terminate` in case a cleanup
   throws. Wasm does not have a runtime to handle this.
3. In case there is no catch-all clause, inserts a call to
   `__cxa_rethrow` at the end of a catchpad in order to unwind to an
   enclosing EH scope.

Reviewers: majnemer, dschuff

Subscribers: jfb, sbc100, jgravelle-google, sunfish, cfe-commits

Differential Revision: https://reviews.llvm.org/D44931

llvm-svn: 333703
2018-05-31 22:18:13 +00:00
Reid Kleckner 26fc531dbc Fix null MSInheritanceAttr deref in CXXRecordDecl::getMSInheritanceModel()
Ensure latest MPT decl has a MSInheritanceAttr when instantiating
templates, to avoid null MSInheritanceAttr deref in
CXXRecordDecl::getMSInheritanceModel().

See PR#37399 for repo / details.

Patch by Andrew Rogers!

Differential Revision: https://reviews.llvm.org/D46664

llvm-svn: 333680
2018-05-31 18:42:29 +00:00
Reid Kleckner 138ab4947c Fix a mangling failure on clang-cl C++17
MethodVFTableLocations in MigrosoftVTableContext contains canonicalized
decl. But, it's sometimes asked to lookup for non-canonicalized decl,
and that causes assertion failure, and compilation failure.

Fixes PR37481.

Patch by Taiju Tsuiki!

Differential Revision: https://reviews.llvm.org/D46929

llvm-svn: 332639
2018-05-17 18:12:18 +00:00
Adrian Prantl 9fc8faf9e6 Remove \brief commands from doxygen comments.
This is similar to the LLVM change https://reviews.llvm.org/D46290.

We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.

Patch produced by

for i in $(git grep -l '\@brief'); do perl -pi -e 's/\@brief //g' $i & done
for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done

Differential Revision: https://reviews.llvm.org/D46320

llvm-svn: 331834
2018-05-09 01:00:01 +00:00
Alexander Kornienko 2a8c18d991 Fix typos in clang
Found via codespell -q 3 -I ../clang-whitelist.txt
Where whitelist consists of:

  archtype
  cas
  classs
  checkk
  compres
  definit
  frome
  iff
  inteval
  ith
  lod
  methode
  nd
  optin
  ot
  pres
  statics
  te
  thru

Patch by luzpaz! (This is a subset of D44188 that applies cleanly with a few
files that have dubious fixes reverted.)

Differential revision: https://reviews.llvm.org/D44188

llvm-svn: 329399
2018-04-06 15:14:32 +00:00
Reid Kleckner 399d96e39c [MS] Emit vftable thunks for functions with incomplete prototypes
Summary:
The following class hierarchy requires that we be able to emit a
this-adjusting thunk for B::foo in C's vftable:

  struct Incomplete;
  struct A {
    virtual A* foo(Incomplete p) = 0;
  };
  struct B : virtual A {
    void foo(Incomplete p) override;
  };
  struct C : B { int c; };

This TU is valid, but lacks a definition of 'Incomplete', which makes it
hard to build a thunk for the final overrider, B::foo.

Before this change, Clang gives up attempting to emit the thunk, because
it assumes that if the parameter types are incomplete, it must be
emitting the thunk for optimization purposes. This is untrue for the MS
ABI, where the implementation of B::foo has no idea what thunks C's
vftable may require. Clang needs to emit the thunk without necessarily
having access to the complete prototype of foo.

This change makes Clang emit a musttail variadic call when it needs such
a thunk. I call these "unprototyped" thunks, because they only prototype
the "this" parameter, which must always come first in the MS C++ ABI.

These thunks work, but they create ugly LLVM IR. If the call to the
thunk is devirtualized, it will be a call to a bitcast of a function
pointer. Today, LLVM cannot inline through such a call, but I want to
address that soon, because we also use this pattern for virtual member
pointer thunks.

This change also implements an old FIXME in the code about reusing the
thunk's computed CGFunctionInfo as much as possible. Now we don't end up
computing the thunk's mangled name and arranging it's prototype up to
around three times.

Fixes PR25641

Reviewers: rjmccall, rsmith, hans

Subscribers: Prazek, cfe-commits

Differential Revision: https://reviews.llvm.org/D45112

llvm-svn: 329009
2018-04-02 20:20:33 +00:00
Reid Kleckner cbec0269ba Fix some DenseMap use-after-rehash bugs and hoist MethodVFTableLocation
This re-lands r328845 with fixes for crbug.com/827810.

The initial motiviation was to hoist MethodVFTableLocation to global
scope so it could be forward declared.

In this patch, I noticed that MicrosoftVTableContext uses some risky
patterns. It has methods that return references to data stored in
DenseMaps. I've made some of them return by value for trivial structs
and I've moved some things into separate allocations.

llvm-svn: 329007
2018-04-02 20:00:39 +00:00
Nico Weber e7c7d70278 Revert r328845, it caused crbug.com/827810.
llvm-svn: 328922
2018-03-31 18:26:25 +00:00
Reid Kleckner 9e3eb9f9d2 Hoist MethodVFTableLocation out of MicrosoftVTableContext, NFC
This allows forward declaring it so that we can add it to
MicrosoftMangleContext::mangleVirtualMemPtrThunk without including
VTableBuilder.h. That saves a hashtable lookup when emitting virtual
member pointer functions.

It also shortens a really long type name. This struct has "VFtable" in
the name, so it seems pretty unlikely that someone will assume it is
generally useful for non-MS C++ ABI stuff.

llvm-svn: 328845
2018-03-29 22:42:24 +00:00
Akira Hatanaka fcbe17c6be [ObjC++] Make parameter passing and function return compatible with ObjC
ObjC and ObjC++ pass non-trivial structs in a way that is incompatible
with each other. For example:
    
typedef struct {
  id f0;
  __weak id f1;
} S;
    
// this code is compiled in c++.
extern "C" {
  void foo(S s);
}
    
void caller() {
  // the caller passes the parameter indirectly and destructs it.
  foo(S());
}
    
// this function is compiled in c.
// 'a' is passed directly and is destructed in the callee.
void foo(S a) {
}
    
This patch fixes the incompatibility by passing and returning structs
with __strong or weak fields using the C ABI in C++ mode. __strong and
__weak fields in a struct do not cause the struct to be destructed in
the caller and __strong fields do not cause the struct to be passed
indirectly.
    
Also, this patch fixes the microsoft ABI bug mentioned here:
    
https://reviews.llvm.org/D41039?id=128767#inline-364710
    
rdar://problem/38887866
    
Differential Revision: https://reviews.llvm.org/D44908

llvm-svn: 328731
2018-03-28 21:13:14 +00:00
Rafael Espindola 1c40647e1c Set dso_local on __ImageBase.
llvm-svn: 328266
2018-03-22 23:02:19 +00:00
Reid Kleckner fb93154bf1 [MS] Don't escape MS C++ names with \01
It is not needed after LLVM r327734. Now it will be easier to copy-paste
IR symbol names from Clang.

llvm-svn: 327738
2018-03-16 20:36:49 +00:00
Reid Kleckner ae9b070111 [MS] Always use base dtors in place of complete/vbase dtors when possible
Summary:
Previously we tried too hard to uphold the fiction that destructor
variants work like they do on Itanium throughout the ABI-neutral parts
of clang. This lead to MS C++ ABI incompatiblities and other bugs. Now,
-mconstructor-aliases will no longer control this ABI detail, and clang
-cc1's LLVM IR output will be this much closer to the clang driver's.

Based on a patch by Zahira Ammarguellat:
  https://reviews.llvm.org/D39063

I've tried to move the logic that Zahira added into MicrosoftCXXABI.cpp.
There is only one ABI-specific detail sticking out, and that is in
CodeGenModule::getAddrOfCXXStructor, where we collapse complete dtors to
base dtors in the MS ABI.

This fixes PR32990.

Reviewers: erichkeane, zahiraam, majnemer, rjmccall

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D44505

llvm-svn: 327732
2018-03-16 19:40:50 +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
Nico Weber 91af2747f2 [ms] Emit vtordisp initializers in a deterministic order.
No effective behavior change, just for cleanliness.
Analysis and typing by me, actual patch mostly by Reid.

Fixes PR36159.
https://reviews.llvm.org/D44223

llvm-svn: 326960
2018-03-07 23:15:20 +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
George Burgess IV 00f70bd933 Remove redundant casts. NFC
So I wrote a clang-tidy check to lint out redundant `isa`, `cast`, and
`dyn_cast`s for fun. This is a portion of what it found for clang; I
plan to do similar cleanups in LLVM and other subprojects when I find
time.

Because of the volume of changes, I explicitly avoided making any change
that wasn't highly local and obviously correct to me (e.g. we still have
a number of foo(cast<Bar>(baz)) that I didn't touch, since overloading
is a thing and the cast<Bar> did actually change the type -- just up the
class hierarchy).

I also tried to leave the types we were cast<>ing to somewhere nearby,
in cases where it wasn't locally obvious what we were dealing with
before.

llvm-svn: 326416
2018-03-01 05:43:23 +00:00
Rafael Espindola b735004615 Start setting dllimport/dllexport in setGVProperties.
This is the next step in setting dso_local for COFF.

The patches changes setGVProperties to first set dllimport/dllexport
and changes a few cases that were setting dllimport/dllexport
manually. With this a few more GVs are marked dso_local.

llvm-svn: 326397
2018-03-01 00:35:47 +00:00
John McCall 9831b843d2 Pass around function pointers as CGCallees, not bare llvm::Value*s.
The intention here is to make it easy to write frontend-assisted CFI
systems by propagating extra information in the CGCallee.

llvm-svn: 324377
2018-02-06 18:52:44 +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
Akira Hatanaka 02914dc127 Add support for attribute 'trivial_abi'.
The 'trivial_abi' attribute can be applied to a C++ class, struct, or
union. It makes special functions of the annotated class (the destructor
and copy/move constructors) to be trivial for the purpose of calls and,
as a result, enables the annotated class or containing classes to be
passed or returned using the C ABI for the underlying type.

When a type that is considered trivial for the purpose of calls despite
having a non-trivial destructor (which happens only when the class type
or one of its subobjects is a 'trivial_abi' class) is passed to a
function, the callee is responsible for destroying the object.

For more background, see the discussions that took place on the mailing
list:

http://lists.llvm.org/pipermail/cfe-dev/2017-November/055955.html
http://lists.llvm.org/pipermail/cfe-commits/Week-of-Mon-20180101/thread.html#214043

rdar://problem/35204524

Differential Revision: https://reviews.llvm.org/D41039

llvm-svn: 324269
2018-02-05 20:23:22 +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
Reid Kleckner 06239e42c6 [MS] Apply adjustments after storing 'this'
Summary:
The MS ABI convention is that the 'this' pointer on entry is the address
of the vfptr that was used to make the virtual method call. In other
words, the pointer on entry always points to the base subobject that
introduced the virtual method. Consider this hierarchy:

  struct A { virtual void f() = 0; };
  struct B { virtual void g() = 0; };
  struct C : A, B {
    void f() override;
    void g() override;
  };

On entry to C::g, [ER]CX will contain the address of C's B subobject,
and C::g will have to subtract sizeof(A) to recover a pointer to C.

Before this change, we applied this adjustment in the prologue and
stored the new value into the "this" local variable alloca used for
debug info. However, MSVC does not do this, presumably because it is
often profitable to fold the adjustment into later field accesses. This
creates a problem, because the debugger expects the variable to be
unadjusted. Unfortunately, CodeView doesn't have anything like DWARF
expressions for computing variables that aren't in the program anymore,
so we have to declare 'this' to be the unadjusted value if we want the
debugger to see the right value.

This has the side benefit that, in optimized builds, the 'this' pointer
will usually be available on function entry because it doesn't require
any adjustment.

Reviewers: hans

Subscribers: aprantl, cfe-commits

Differential Revision: https://reviews.llvm.org/D40109

llvm-svn: 318440
2017-11-16 19:09:36 +00:00
Reid Kleckner 3da37e05f7 [MS] Don't bail on replacing dllimport vbase dtors with base dtors
Fix PR32990 by effectively reverting r283063 and solving it a different
way.

We want to limit the hack to not replace equivalent available_externally
dtors specifically to libc++, which uses always_inline. It seems certain
versions of libc++ do not provide all the symbols that an explicit
template instantiation is expected to provide.

If we get to the code that forms a real alias, only *then* check if this
is available_externally, and do that by asking a better question, which
is "is this a declaration for the linker?", because *that's* what means
we can't form an alias to it.

As a follow-on simplification, remove the InEveryTU parameter. Its last
use guarded this code for forming aliases, but we should never form
aliases to declarations, regardless of what we know about every TU.

llvm-svn: 315656
2017-10-13 00:53:02 +00:00
Richard Smith 96cd671cd6 PR19668, PR23034: Fix handling of move constructors and deleted copy
constructors when deciding whether classes should be passed indirectly.

This fixes ABI differences between Clang and GCC:

 * Previously, Clang ignored the move constructor when making this
   determination. It now takes the move constructor into account, per
   https://github.com/itanium-cxx-abi/cxx-abi/pull/17 (this change may
   seem recent, but the ABI change was agreed on the Itanium C++ ABI
   list a long time ago).

 * Previously, Clang's behavior when the copy constructor was deleted
   was unstable -- depending on whether the lazy declaration of the
   copy constructor had been triggered, you might get different behavior.
   We now eagerly declare the copy constructor whenever its deletedness
   is unclear, and ignore deleted copy/move constructors when looking for
   a trivial such constructor.

This also fixes an ABI difference between Clang and MSVC:

 * If the copy constructor would be implicitly deleted (but has not been
   lazily declared yet), for instance because the class has an rvalue
   reference member, we would pass it directly. We now pass such a class
   indirectly, matching MSVC.

Based on a patch by Vassil Vassilev, which was based on a patch by Bernd
Schmidt, which was based on a patch by Reid Kleckner!

This is a re-commit of r310401, which was reverted in r310464 due to ARM
failures (which should now be fixed).

llvm-svn: 310983
2017-08-16 01:49:53 +00:00
Diana Picus 0c9f193acc Revert "PR19668, PR23034: Fix handling of move constructors and deleted copy constructors when deciding whether classes should be passed indirectly."
This reverts commit r310401 because it seems to have broken some ARM
bot(s).

llvm-svn: 310464
2017-08-09 12:22:25 +00:00
Richard Smith f1a425edb7 PR19668, PR23034: Fix handling of move constructors and deleted copy
constructors when deciding whether classes should be passed indirectly.

This fixes ABI differences between Clang and GCC:

 * Previously, Clang ignored the move constructor when making this
   determination. It now takes the move constructor into account, per
   https://github.com/itanium-cxx-abi/cxx-abi/pull/17 (this change may
   seem recent, but the ABI change was agreed on the Itanium C++ ABI
   list a long time ago).

 * Previously, Clang's behavior when the copy constructor was deleted
   was unstable -- depending on whether the lazy declaration of the
   copy constructor had been triggered, you might get different behavior.
   We now eagerly declare the copy constructor whenever its deletedness
   is unclear, and ignore deleted copy/move constructors when looking for
   a trivial such constructor.

This also fixes an ABI difference between Clang and MSVC:

 * If the copy constructor would be implicitly deleted (but has not been
   lazily declared yet), for instance because the class has an rvalue
   reference member, we would pass it directly. We now pass such a class
   indirectly, matching MSVC.

llvm-svn: 310401
2017-08-08 19:12:28 +00:00
Richard Smith ae8d62c9c5 Add branch weights to branches for static initializers.
The initializer for a static local variable cannot be hot, because it runs at
most once per program. That's not quite the same thing as having a low branch
probability, but under the assumption that the function is invoked many times,
modeling this as a branch probability seems reasonable.

For TLS variables, the situation is less clear, since the initialization side
of the branch can run multiple times in a program execution, but we still
expect initialization to be rare relative to non-initialization uses. It would
seem worthwhile to add a PGO counter along this path to make this estimation
more accurate in future.

For globals with guarded initialization, we don't yet apply any branch weights.
Due to our use of COMDATs, the guard will be reached exactly once per DSO, but
we have no idea how many DSOs will define the variable.

llvm-svn: 309195
2017-07-26 22:01:09 +00:00
Richard Smith 1283e9868d [modules ts] Basic for module linkage.
In addition to the formal linkage rules, the Modules TS includes cases where
internal-linkage symbols within a module interface unit can be referenced from
outside the module via exported inline functions / templates. We give such
declarations "module-internal linkage", which is formally internal linkage, but
results in an externally-visible symbol.

llvm-svn: 307434
2017-07-07 20:04:28 +00:00
Alexey Bataev 56223237b0 [DebugInfo] Add kind of ImplicitParamDecl for emission of FlagObjectPointer.
Summary:
If the first parameter of the function is the ImplicitParamDecl, codegen
automatically marks it as an implicit argument with `this` or `self`
pointer. Added internal kind of the ImplicitParamDecl to separate
'this', 'self', 'vtt' and other implicit parameters from other kind of
parameters.

Reviewers: rjmccall, aaron.ballman

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D33735

llvm-svn: 305075
2017-06-09 13:40:18 +00:00
Piotr Padlewski d3b1cbd17f Emit available_externally vtables opportunistically
Summary:
We can emit vtable definition having inline function
if they are all emitted.

Reviewers: rjmccall, rsmith

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D33437

llvm-svn: 304394
2017-06-01 08:04:05 +00:00
Simon Pilgrim 2c51880a82 Spelling mistakes in comments. NFCI. (PR27635)
llvm-svn: 299083
2017-03-30 14:13:19 +00:00
Reid Kleckner de86482ce0 Update Clang for LLVM rename AttributeSet -> AttributeList
llvm-svn: 298394
2017-03-21 16:57:30 +00:00
John McCall 5ad740756f Promote ConstantInitBuilder to be a public CodeGen API; it's
a generally useful utility for other frontends.  NFC.

llvm-svn: 296806
2017-03-02 20:04:19 +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
Peter Collingbourne 1e1475ace5 Move vtable type metadata emission behind a cc1-level flag.
In ThinLTO mode, type metadata will require the module to be written as a
multi-module bitcode file, which is currently incompatible with the Darwin
linker. It is also useful to be able to enable or disable multi-module bitcode
for testing purposes. This introduces a cc1-level flag, -f{,no-}lto-unit,
which is used by the driver to enable multi-module bitcode on all but
Darwin+ThinLTO, and can also be used to enable/disable the feature manually.

Differential Revision: https://reviews.llvm.org/D28877

llvm-svn: 292448
2017-01-18 23:55:27 +00:00
Saleem Abdulrasool a9e1450b07 CodeGen: update comment about RTTI field
The MS ABI RTTI has a reserved field which is used as a cache for the
demangled name.  It must be zero-initialized, which is used as a hint by
the runtime to say that the cache has not been populated.  Since this
field is populated at runtime, the RTTI structures must be placed in the
.data section rather than .rdata.  NFC

llvm-svn: 290799
2017-01-01 19:16:02 +00:00
Saleem Abdulrasool 6cb0744934 CodeGen: fix runtime function dll storage
Properly attribute DLL storage to runtime functions.  When generating the
runtime function, scan for an existing declaration which may provide an explicit
declaration (local storage) or a DLL import or export storage from the user.
Honour that if available.  Otherwise, if building with a local visibility of the
public or standard namespaces (-flto-visibility-public-std), give the symbols
local storage (it indicates a /MT[d] link, so static runtime).  Otherwise,
assume that the link is dynamic, and give the runtime function dllimport
storage.

This allows for implementations to get the correct storage as long as they are
properly declared, the user to override the import storage, and in case no
explicit storage is given, use of the import storage.

llvm-svn: 289776
2016-12-15 06:59:05 +00:00
Peter Collingbourne 2849c4e841 CodeGen: New vtable group representation: struct of vtable arrays.
In a future change, this representation will allow us to use the new inrange
annotation on getelementptr to allow the optimizer to split vtable groups.

Differential Revision: https://reviews.llvm.org/D22296

llvm-svn: 289584
2016-12-13 20:40:39 +00:00
Erich Keane 13c7ec5c65 [MS-ABI]V-base dtor called more than needed when throw happens in v-base ctor in window. Need add "complete object flag" check in eh cleanup code.
The problem only happen on window ( A MS-ABI issuer )

The nature of the problem is virtual base dtor called more than it is needed after exception throw in inheriting base class(with virtual bases) ctor.

The root problem is when throw happen, not all virtual base classes have been contructed, so not all virtual base dtors are need to call for ehcleanup.

clang has code to handle vbase initialization: basically add check for "complete object flag" before call to v-base ctor.
But that part is missing for cleanup code.

To fix this add similar code as v-base init to cleanup code, same algorithm.

1> Add new routine:
EmitDtorCompleteObjectHandler

With corresponding to EmitCtorCompleteObjectHandler

2> In the EmitDestructorCal
Call EmitDtorCompleteObjectHandler when generate ehcleanup inside ctor.

Just add check for "complete object flag" before call to v-base dtor.

Without my change:
ehcleanup: ; preds = %ctor.skip_vbases

%13 = cleanuppad within none [], !dbg !66
%14 = bitcast %struct.class_0* %this1 to i8*, !dbg !66
%15 = getelementptr inbounds i8, i8* %14, i64 8, !dbg !66
%16 = bitcast i8* %15 to %struct.class_2*, !dbg !66
call void @"\01??1class_2@@UEAA@XZ"(%struct.class_2* %16) #6 [ "funclet"(token

%13) ], !dbg !66

cleanupret from %13 unwind to caller, !dbg !66

with my change:
ehcleanup: ; preds = %ctor.skip_vbases

%13 = cleanuppad within none [], !dbg !66
%14 = bitcast %struct.class_0* %this1 to i8*, !dbg !66
%15 = getelementptr inbounds i8, i8* %14, i64 8, !dbg !66
%16 = bitcast i8* %15 to %struct.class_2*, !dbg !66
%is_complete_object4 = icmp ne i32 %is_most_derived2, 0, !dbg !66
br i1 %is_complete_object4, label %Dtor.dtor_vbase, label %Dtor.skip_vbase, !d

bg !66

Dtor.dtor_vbase: ; preds = %ehcleanup

call void @"\01??1class_2@@UEAA@XZ"(%struct.class_2* %16) #6 [ "funclet"(token

%13) ], !dbg !66

br label %Dtor.skip_vbase, !dbg !66

Dtor.skip_vbase: ; preds = %Dtor.dtor_vbase, %ehcleanup

cleanupret from %13 unwind to caller, !dbg !66

Please let me know you need more info.

Patch by Jennifer Yu.

Differential Revision: https://reviews.llvm.org/D27358

llvm-svn: 288869
2016-12-07 00:21:45 +00:00
John McCall 9c6cb7642e Make CGVTables use ConstantInitBuilder. NFC.
llvm-svn: 288081
2016-11-28 22:18:33 +00:00
Reid Kleckner c01ee7505a Remove C++ default arg side table for MS ABI ctor closures
Summary:
We don't need a side table in ASTContext to hold CXXDefaultArgExprs. The
important part of building the CXXDefaultArgExprs was to ODR use the
default argument expressions, not to make AST nodes. Refactor the code
to only check the default argument, and remove the side table in
ASTContext which wasn't being serialized.

Fixes PR31121

Reviewers: thakis, rsmith, majnemer

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D27007

llvm-svn: 287774
2016-11-23 16:51:30 +00:00
Peter Collingbourne 120eb54422 Sema, CodeGen: Ensure that an implicit copy ctor is available more often under the Microsoft C++ ABI.
This is needed because whether the constructor is deleted can control whether
we pass structs by value directly.

To fix this properly we probably want a more direct way for CodeGen to ask
whether the constructor was deleted.

Fixes PR31049.

Differential Revision: https://reviews.llvm.org/D26822

llvm-svn: 287600
2016-11-22 00:21:43 +00:00
Adrian Prantl d3c4e1b11f Fix PR31029 by attaching an artificial debug location to msabi thunks.
This was a latent bug that was recently uncovered by r286400.

llvm-svn: 287134
2016-11-16 18:49:47 +00:00
David Majnemer 07c915e1d5 [MS ABI] Reuse getVFPtrOffsets instead of using getClassAtVTableLocation
getClassAtVTableLocation hunts through virtual bases without using the
MDC layout which is indicative of a bug.

Instead, reuse the getVFPtrOffsets machinery to calculate which
subobject within the MDC is responsible for the vfptr.

Differential Revision: https://reviews.llvm.org/D25895

llvm-svn: 285315
2016-10-27 17:11:51 +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
Hans Wennborg 0a79a1203a MS ABI: Fix assert when generating virtual function call with virtual bases and -flto (PR30731)
getClassAtVTableLocation() was calling
ASTRecordLayout::getBaseClassOffset() on a virtual base, causing an
assert.

Differential Revision: https://reviews.llvm.org/D25779

llvm-svn: 284624
2016-10-19 18:04:27 +00:00
Justin Lebar 562914e505 Use unique_ptr for VPtrLocationsMap and VPtrInfoVector.
Reviewers: timshen

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D25422

llvm-svn: 283770
2016-10-10 16:26:29 +00:00
David Majnemer cb60a4305b [MS ABI] Add /include directives for dynamic TLS
MSVC emits /include directives in the .drective section for the
__dyn_tls_init function (decorated as ___dyn_tls_init@12 for 32-bit).

This fixes PR30347.

llvm-svn: 281189
2016-09-12 02:51:43 +00:00
Peter Collingbourne e53683f97b CodeGen: Clean up implementation of vtable initializer builder. NFC.
- Simplify signature of CreateVTableInitializer function.
- Move vtable component builder to a separate function.
- Remove unnecessary accessors from VTableLayout class.

This is in preparation for a future change that will alter the type of the
vtable initializer.

Differential Revision: https://reviews.llvm.org/D22642

llvm-svn: 280897
2016-09-08 01:14:39 +00:00
Reid Kleckner 44051e63de [MS] Pass non-trivially-copyable objects indirectly on Windows ARM
This isn't exactly what MSVC does, unfortunately. MSVC does not pass
objects with destructors but no copy constructors by address. More ARM
expertise is required to really understand what should be done here.

Fixes PR29136.

llvm-svn: 279764
2016-08-25 18:23:28 +00:00
Justin Lebar ed4f172c00 Don't crash when generating code for __attribute__((naked)) member functions.
Summary:
Previously this crashed inside EmitThisParam().  There should be no
prelude for naked functions, so just skip the whole thing.

Reviewers: majnemer

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D22715

llvm-svn: 276925
2016-07-27 22:04:24 +00:00
Reid Kleckner 8ad06d6546 [MS] Improve VPtrInfo field names and doc comments
'ReusingBase' was a terrible name. It might actually refer to the most
derived class, which is not a base. 'BaseWithVPtr' was also bad, since
again, it could refer to the most derived class. It was actually the
first base to introduce the vptr, so now it is 'IntroducingObject'.

llvm-svn: 276120
2016-07-20 14:40:25 +00:00
David Majnemer 526793d14c [MS ABI] Support throwing/catching __unaligned types
We need to mark the appropriate bits in ThrowInfo and HandlerType so
that the personality routine can correctly handle qualification
conversions.

llvm-svn: 275154
2016-07-12 04:42:50 +00:00
David Majnemer 177553511d [MS ABI] Some code cleanups
Don't create unnecessary truncations if the result will not be used.
Also prefer preforming math before the truncation, it makes it a little
easier to reason about.

llvm-svn: 274984
2016-07-09 19:26:25 +00:00
Reid Kleckner 0358cbfc0a [DebugInfo] Set DISubprogram ThisAdjustment in the MS ABI
llvm-svn: 274326
2016-07-01 02:41:25 +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
Peter Collingbourne bcf909d737 Update clang for D20348
Differential Revision: http://reviews.llvm.org/D20339

llvm-svn: 272710
2016-06-14 21:02:05 +00:00
David Majnemer 833b91eee8 [MS ABI] Delegating constructors should not assume they are most derived
A constructor needs to know whether or not it is most derived in order
to determine if it is responsible for virtual bases.  Delegating
constructors assumed they were most derived.

llvm-svn: 269465
2016-05-13 20:05:09 +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
Aaron Ballman abd466ed04 Silencing warnings from MSVC 2015 Update 2. Both of these changes silence "C4334 '<<': result of 32-bit shift implicitly converted to 64 bits (was 64-bit shift intended?)". NFC.
llvm-svn: 264932
2016-03-30 21:33:34 +00:00
Alexey Samsonov ae81bbb496 EmitCXXStructorCall -> EmitCXXDestructorCall. NFC.
This function is only used in Microsoft ABI and only to emit
destructors. Rename/simplify it accordingly.

llvm-svn: 263081
2016-03-10 00:20:37 +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
David Majnemer 46e39cc6b0 [MS ABI] Correctly handle dllimport'd explicit instantiation declaration w/ vbases
We gave a VBTable dllimport storage class and external linkage while
also providing an initializer.  An initializer is only valid if the
VBTable has available_externally linkage.  Fix this by setting the
linkage to available_externally in situ while generating the
initializer.

This fixes PR26686.

llvm-svn: 261535
2016-02-22 17:22:08 +00:00
David Majnemer 2d8b2008c8 Revert "Revert r260388 "[MS ABI] Never reference dllimport'd vtables""
This reverts commit r260449.

We would supress our emission of vftable definitions if we thought
another translation unit would provide the definition because we saw an
explicit instantiation declaration.  This is not the case with
dllimport, we want to synthesize a definition of the vftable regardless.

This fixes PR26569.

llvm-svn: 260548
2016-02-11 17:49:28 +00:00
Hans Wennborg 8fab56e0dc Revert r260388 "[MS ABI] Never reference dllimport'd vtables"
This caused the compiler to fail with "invalid linkage type
for global declaration" (PR26569).

llvm-svn: 260449
2016-02-10 22:18:37 +00:00
Reid Kleckner d16cebef5d Silence some MSVC false positive warnings about integer zexts and falling off the end of a covered switch
llvm-svn: 260411
2016-02-10 19:09:15 +00:00
David Majnemer 1b2d0b4637 [MS ABI] Never reference dllimport'd vtables
Referencing a dllimported vtable is impossible in a constexpr
constructor.  It would be friendlier to C++ programmers if we
synthesized a copy of the vftable which referenced imported virtual
functions.  This would let us initialize the object in a way which
preserves both the intent to import functionality from another DLL while
also making constexpr work.

Differential Revision: http://reviews.llvm.org/D17061

llvm-svn: 260388
2016-02-10 17:40:47 +00:00
David Majnemer 470ee61e01 [MS ABI] Cleanup emitVTableDefinitions
Use the VFTable components to determine whether or not we should emit
RTTI data instead of duplicating the VFTableBuilder's logic.

llvm-svn: 260238
2016-02-09 17:27:52 +00:00
David Majnemer bd173badb4 [MS ABI] Don't emit RTTI descriptors for dllimport vtables
A dllimport'd vtable always points one past the RTTI data, this means
that the initializer will never end up referencing the data.  Our
emission is a harmless waste.

llvm-svn: 260062
2016-02-07 22:42:05 +00:00
Eric Christopher d160c50f6b Use a consistent spelling for vtables.
llvm-svn: 259137
2016-01-29 01:35:53 +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
David Majnemer 4e52d6f811 Update clang to use the updated LLVM EH instructions
Depends on D15139.

Reviewers: rnk

Differential Revision: http://reviews.llvm.org/D15140

llvm-svn: 255423
2015-12-12 05:39:21 +00:00