Commit Graph

287 Commits

Author SHA1 Message Date
Richard Smith fda59e5851 Implement name mangling proposal for exception specifications from cxx-abi-dev 2016-10-11.
This has the following ABI impact:

 1) Functions whose parameter or return types are non-throwing function pointer
    types have different manglings in c++1z mode from prior modes. This is
    necessary because c++1z permits overloading on the noexceptness of function
    pointer parameter types. A warning is issued for cases that will change
    manglings in c++1z mode.

 2) Functions whose parameter or return types contain instantiation-dependent
    exception specifications change manglings in all modes. This is necessary
    to support overloading on / SFINAE in these exception specifications, which
    a careful reading of the standard indicates has essentially always been
    permitted.

Note that, in order to be affected by these changes, the code in question must
specify an exception specification on a function pointer/reference type that is
written syntactically within the declaration of another function. Such
declarations are very rare, and I have so far been unable to find any code
that would be affected by this. (Note that such things will probably become
more common in C++17, since it's a lot easier to get a noexcept function type
as a function parameter / return type there.)

This change does not affect the set of symbols produced by a build of clang,
libc++, or libc++abi.

llvm-svn: 285150
2016-10-26 01:05:54 +00:00
Richard Smith afecd83746 Fix bug where one of the cases where we mangle a <bare-unresolved-name> failed
to emit the <template-args> portion. Refactor so that mangleUnresolvedName
actually emits the entire <unresolved-name>, so this mistake is harder to make
again.

llvm-svn: 285022
2016-10-24 20:47:04 +00:00
Richard Smith 4631be7402 Fix mangling of implicit calls to operator-> to only include a single "pt",
rather than including an extra one for each level of 'operator->()' invoked.

llvm-svn: 285015
2016-10-24 20:29:40 +00:00
Alex Lorenz 7ba609a220 Fix PR30440: Initialize FunctionTypeDepth in CXXNameMangler
This commit fixes PR 30440 by initializing CXXNameMangler's FunctionTypeDepth
in the two constructors added in r274222 (The commit that caused this
regression).

rdar://28455269

Differential Revision: https://reviews.llvm.org/D24932

llvm-svn: 283428
2016-10-06 09:37:15 +00:00
Dmitry Polukhin fda467b252 PR30401: Fix substitutions for functions with abi_tag
llvm-svn: 282059
2016-09-21 08:27:03 +00:00
Manman Ren e6be26c8d4 ObjectiveC generics: Add ObjCTypeParamType in the type system.
We also need to add ObjCTypeParamTypeLoc. ObjCTypeParamType supports the
representation of "T <protocol>" where T is a type parameter. Before this,
we use TypedefType to represent the type parameter for ObjC.

ObjCTypeParamType has "ObjCTypeParamDecl *OTPDecl" and it extends from
ObjCProtocolQualifiers. It is a non-canonical type and is canonicalized
to the underlying type with the protocol qualifiers.

rdar://24619481
rdar://25060179

Differential Revision: http://reviews.llvm.org/D23079

llvm-svn: 281355
2016-09-13 17:25:08 +00:00
Richard Smith da38363784 P0217R3: code generation support for decomposition declarations.
llvm-svn: 278642
2016-08-15 01:33:41 +00:00
Richard Smith bdb84f374c P0217R3: Parsing support and framework for AST representation of C++1z
decomposition declarations.

There are a couple of things in the wording that seem strange here:
decomposition declarations are permitted at namespace scope (which we partially
support here) and they are permitted as the declaration in a template (which we
reject).

llvm-svn: 276492
2016-07-22 23:36:59 +00:00
Richard Smith cb2ba5a5a7 Fix some minor issues found by Coverity.
llvm-svn: 275925
2016-07-18 22:37:35 +00:00
Erik Pilkington 29099ded0c [ObjC] Implement @available in the Parser and AST
This patch adds a new AST node: ObjCAvailabilityCheckExpr, and teaches the
Parser and Sema to generate it. This node represents an availability check of
the form:

  @available(macos 10.10, *);

Which will eventually compile to a runtime check of the host's OS version. This
is the first patch of the feature I proposed here:
http://lists.llvm.org/pipermail/cfe-dev/2016-July/049851.html

Differential Revision: https://reviews.llvm.org/D22171

llvm-svn: 275654
2016-07-16 00:35:23 +00:00
David Majnemer 6d2b60a2be [ItaniumMangle] Correctly mangle BuiltinTemplateDecls
A BuiltinTemplateDecl has no underlying templated decl and as such they
cannot be relied upon for mangling.  The ItaniumMangler had some bugs
here which lead to crashes.

This fixes PR28519.

llvm-svn: 275190
2016-07-12 16:48:17 +00:00
Dmitry Polukhin 90bb49e362 [GCC] PR23529 Mangler part of attrbute abi_tag support
Original patch by Stefan Bühler http://reviews.llvm.org/D12834

Difference between original and this one:
- fixed all failing tests
- fixed mangling for global variable outside namespace
- emit ABI tags for guards and local names
- clang-format + other stylistic changes
- significantly reworked patch according to Richard's suggestions

Sema part, committed before http://reviews.llvm.org/D17567

Differential revision: http://reviews.llvm.org/D18035

llvm-svn: 274222
2016-06-30 09:40:38 +00:00
Nikolay Haustov 8c6538b86d AMDGPU: Set amdgpu_kernel calling convention for OpenCL kernels.
Summary:
Summary:
Change Clang calling convention SpirKernel to OpenCLKernel.
Set calling convention OpenCLKernel for amdgcn as well.
Add virtual method .getOpenCLKernelCallingConv() to TargetCodeGenInfo
and use it to set target calling convention for AMDGPU and SPIR.
Update tests.

Reviewers: rsmith, tstellarAMD, Anastasia, yaxunl

Subscribers: kzhuravl, cfe-commits

Differential Revision: http://reviews.llvm.org/D21367

llvm-svn: 274220
2016-06-30 09:06:33 +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
Rafael Espindola ea2a5e6897 Delete dead code.
Found by gcc 6.

llvm-svn: 273300
2016-06-21 19:19:31 +00:00
David Majnemer 140065a693 [ItaniumMangle] Mangle dependent __underlying_type correctly
We attempted to use the UnaryTransformType's UnderlyingType instead of
it's BaseType.  This is not correct for dependent UnaryTransformType
because the have no underlying type.

This fixes PR28045.

llvm-svn: 272079
2016-06-08 00:34:15 +00:00
Nico Weber fb42078d7c Fix mangled name of method with ns_consumed parameters.
When a function/method use a parameter with "ns_consumed" attribute,
ensure that the mangled name is the same whether -fobjc-arc is used
or not.

Since "ns_consumed" attribute is generally used to inform ARC that
a function/method does sink the reference, it mean it is usually
implemented in a compilation unit compiled without -fobjc-arc but
used form a compilation unit compiled with it.

Originally found while trying to use "ns_consumed" attribute in an
Objective-C++ file in Chromium (http://crbug.com/599980) where it
caused a linker error.

Regression introduced by revision 262278 (previously the attribute
was incorrectly not part of the mangled name).

Patch from Sylvain Defresne <sdefresne@chromium.org>!
http://reviews.llvm.org/D20113

llvm-svn: 270702
2016-05-25 14:15:08 +00:00
Nemanja Ivanovic bb1ea2d613 Enable support for __float128 in Clang and enable it on pertinent platforms
This patch corresponds to reviews:
http://reviews.llvm.org/D15120
http://reviews.llvm.org/D19125

It adds support for the __float128 keyword, literals and target feature to
enable it. Based on the latter of the two aforementioned reviews, this feature
is enabled on Linux on i386/X86 as well as SystemZ.
This is also the second attempt in commiting this feature. The first attempt
did not enable it on required platforms which caused failures when compiling
type_traits with -std=gnu++11.

If you see failures with compiling this header on your platform after this
commit, it is likely that your platform needs to have this feature enabled.

llvm-svn: 268898
2016-05-09 08:52:33 +00:00
Richard Smith ec24bbe332 PR27549: fix bug that resulted in us giving a translation-unit-scope variable a
mangled name if it happened to be declared in an 'extern "C++"' context. This
also causes us to use the '_ZL' mangling rather than the '_Z' mangling for
internal-linkage entities that are wrapped in a language linkage construct.

llvm-svn: 267969
2016-04-29 01:23:20 +00:00
Nemanja Ivanovic d7d45bf8ce Revert 266186 as it breaks anything that includes type_traits on some platforms
Since this patch provided support for the __float128 type but disabled it
on all platforms by default, some platforms can't compile type_traits with
-std=gnu++11 since there is a specialization with __float128.
This reverts the patch until D19125 is approved (i.e. we know which platforms
need this support enabled).

llvm-svn: 266460
2016-04-15 18:04:13 +00:00
Nemanja Ivanovic 50f29e06a1 Enable support for __float128 in Clang
This patch corresponds to review:
http://reviews.llvm.org/D15120

It adds support for the __float128 keyword, literals and a target feature to
enable it. This support is disabled by default on all targets and any target
that has support for this type is free to add it.

Based on feedback that I've received from target maintainers, this appears to
be the right thing for most targets. I have not heard from the maintainers of
X86 which I believe supports this type. I will subsequently investigate the
impact of enabling this on X86.

llvm-svn: 266186
2016-04-13 09:49:45 +00:00
Alexey Bader b62f14400f [OpenCL] Move OpenCLImageTypes.def from clangAST to clangBasic library.
Putting OpenCLImageTypes.def to clangAST library violates layering requirement: "It's not OK for a Basic/ header to include an AST/ header".
This fixes the modules build.

Differential revision: http://reviews.llvm.org/D18954
Reviewers: Richard Smith, Vassil Vassilev.

llvm-svn: 266180
2016-04-13 08:33:41 +00:00
Alexey Bader 954ba21f85 [OpenCL] Complete image types support.
I. Current implementation of images is not conformant to spec in the following points:
  1. It makes no distinction with respect to access qualifiers and therefore allows to use images with different access type interchangeably. The following code would compile just fine:

        void write_image(write_only image2d_t img);
        kernel void foo(read_only image2d_t img) { write_image(img); } // Accepted code

     which is disallowed according to s6.13.14.

  2. It discards access qualifier on generated code, which leads to generated code for the above example:

        call void @write_image(%opencl.image2d_t* %img);

     In OpenCL2.0 however we can have different calls into write_image with read_only and wite_only images.
     Also generally following compiler steps have no easy way to take different path depending on the image access: linking to the right implementation of image types, performing IR opts and backend codegen differently.

  3. Image types are language keywords and can't be redeclared s6.1.9, which can happen currently as they are just typedef names.
  4. Default access qualifier read_only is to be added if not provided explicitly.

II. This patch corrects the above points as follows:
  1. All images are encapsulated into a separate .def file that is inserted in different points where image handling is required. This avoid a lot of code repetition as all images are handled the same way in the code with no distinction of their exact type.
  2. The Cartesian product of image types and image access qualifiers is added to the builtin types. This simplifies a lot handling of access type mismatch as no operations are allowed by default on distinct Builtin types. Also spec intended access qualifier as special type qualifier that are combined with an image type to form a distinct type (see statement above - images can't be created w/o access qualifiers).
  3. Improves testing of images in Clang.

Author: Anastasia Stulova
Reviewers: bader, mgrang.
Subscribers: pxli168, pekka.jaaskelainen, yaxunl.
Differential Revision: http://reviews.llvm.org/D17821

llvm-svn: 265783
2016-04-08 13:40:33 +00:00
Roman Levenstein 35aa5cecf2 Add attributes for preserve_mostcc/preserve_allcc calling conventions to the C/C++ front-end
Till now, preserve_mostcc/preserve_allcc calling convention attributes were only
available at the LLVM IR level. This patch adds attributes for
preserve_mostcc/preserve_allcc calling conventions to the C/C++ front-end.

The code was mostly written by Juergen Ributzka.
I just added support for the AArch64 target and tests.

Differential Revision: http://reviews.llvm.org/D18025

llvm-svn: 263647
2016-03-16 18:00:46 +00:00
John McCall 477f2bb0d5 Semantic analysis for the swiftcall calling convention.
I've tried to keep the infrastructure behind parameter ABI
treatments fairly general.

llvm-svn: 262587
2016-03-03 06:39:32 +00:00
Alexey Bataev 94a4f0cb5f [OPENMP 4.0] Initial support for 'omp declare reduction' construct.
Add parsing, sema analysis and serialization/deserialization for 'declare reduction' construct.
User-defined reductions are defined as

#pragma omp declare reduction( reduction-identifier : typename-list : combiner ) [initializer ( initializer-expr )]
These custom reductions may be used in 'reduction' clauses of OpenMP constructs. The combiner specifies how partial results can be combined into a single value. The
combiner can use the special variable identifiers omp_in and omp_out that are of the type of the variables being reduced with this reduction-identifier. Each of them will
denote one of the values to be combined before executing the combiner. It is assumed that the special omp_out identifier will refer to the storage that holds the resulting
combined value after executing the combiner.
As the initializer-expr value of a user-defined reduction is not known a priori the initializer-clause can be used to specify one. Then the contents of the initializer-clause
will be used as the initializer for private copies of reduction list items where the omp_priv identifier will refer to the storage to be initialized. The special identifier
omp_orig can also appear in the initializer-clause and it will refer to the storage of the original variable to be reduced.
Differential Revision: http://reviews.llvm.org/D11182

llvm-svn: 262582
2016-03-03 05:21:39 +00:00
John McCall 07daf721fb Mangle extended qualifiers in the proper order and mangle the
ARC ownership-convention function type modifications.

According to the Itanium ABI, vendor extended qualifiers are
supposed to be mangled in reverse-alphabetical order before
any CVR qualifiers.  The ARC function type conventions are
plausibly order-significant (they are associated with the
function type), which permits us to ignore the need to correctly
inter-order them with any other vendor qualifiers on the parameter
and return types.

Implementing these rules correctly is technically an ABI break.
Apple is comfortable with the risk of incompatibility here for
the ARC features, and I believe that address-space qualification
is still uncommon enough to allow us to adopt the conforming
rule without serious risk.  Still, targets which make heavy
use of address space qualification may want to revert to the
non-conforming order.

llvm-svn: 262414
2016-03-01 22:18:03 +00:00
Richard Smith 8467c87aa2 Fix typo in OpenCL type mangling. This is still bogus (we should either use the
actual source name of the typedef or a vendor mangling) but at least it stands
a chance of demangling now.

We would also benefit from some test coverage of this (OpenCL +
__attribute__((overloadable)) is probably required to reach this).

llvm-svn: 259618
2016-02-03 01:43:59 +00:00
Craig Topper f42e031c79 Replace usage of llvm::utostr_32 with just llvm::utostr. While this is less efficient, its unclear that the one place using the _32 version was doing so for efficiency.
llvm-svn: 259316
2016-01-31 04:20:03 +00:00
Xiuli Pan 9c14e28211 [OpenCL] Pipe type support
Summary:
Support for OpenCL 2.0 pipe type.
This is a bug-fix version for bader's patch reviews.llvm.org/D14441


Reviewers: pekka.jaaskelainen, Anastasia

Subscribers: bader, Anastasia, cfe-commits

Differential Revision: http://reviews.llvm.org/D15603

llvm-svn: 257254
2016-01-09 12:53:17 +00:00
Benjamin Kramer b42d9a5f06 Replace llvm::utostr calls in Twine context with Twines. NFC.
llvm-svn: 256377
2015-12-24 10:07:37 +00:00
James Y Knight 04ec5bfad8 [TrailingObjects] Convert ASTTemplateKWAndArgsInfo and ASTTemplateArgumentListInfo.
Doing so required separating them so that the former doesn't inherit
from the latter anymore. Investigating that, it became clear that the
inheritance wasn't actually providing real value in any case.

So also:
- Remove a bunch of redundant functions (getExplicitTemplateArgs,
  getOptionalExplicitTemplateArgs) on various Expr subclasses which
  depended on the inheritance relationship.
- Switched external callers to use pre-existing accessors that return the
  data they're actually interested in (getTemplateArgs,
  getNumTemplateArgs, etc).
- Switched internal callers to use pre-existing getTemplateKWAndArgsInfo.

llvm-svn: 256359
2015-12-24 02:59:37 +00:00
George Burgess IV 3e3bb95b69 Add the `pass_object_size` attribute to clang.
`pass_object_size` is our way of enabling `__builtin_object_size` to
produce high quality results without requiring inlining to happen
everywhere.

A link to the design doc for this attribute is available at the
Differential review link below.

Differential Revision: http://reviews.llvm.org/D13263

llvm-svn: 254554
2015-12-02 21:58:08 +00:00
Alexey Bataev f763027f04 [MSVC] 'property' with an empty array in array subscript expression.
MSVC supports 'property' attribute and allows to apply it to the declaration of an empty array in a class or structure definition.
For example:
```
__declspec(property(get=GetX, put=PutX)) int x[];
```
The above statement indicates that x[] can be used with one or more array indices. In this case, i=p->x[a][b] will be turned into i=p->GetX(a, b), and p->x[a][b] = i will be turned into p->PutX(a, b, i);
Differential Revision: http://reviews.llvm.org/D13336

llvm-svn: 254067
2015-11-25 12:01:00 +00:00
Richard Smith e301ba2b48 Add support for GCC's '__auto_type' extension, per the GCC manual:
https://gcc.gnu.org/onlinedocs/gcc/Typeof.html

Differences from the GCC extension:
 * __auto_type is also permitted in C++ (but only in places where
   it could appear in C), allowing its use in headers that might
   be shared across C and C++, or used from C++98
 * __auto_type can be combined with a declarator, as with C++ auto
   (for instance, "__auto_type *p")
 * multiple variables can be declared in a single __auto_type
   declaration, with the C++ semantics (the deduced type must be
   the same in each case)

This patch also adds a missing restriction on applying typeof to
a bit-field, which GCC has historically rejected in C (due to
lack of clarity as to whether the operand should be promoted).
The same restriction also applies to __auto_type in C (in both
GCC and Clang).

This also fixes PR25449.

Patch by Nicholas Allegra!

llvm-svn: 252690
2015-11-11 02:02:15 +00:00
Richard Smith 9f690bd80b [coroutines] Creation of promise object, lookup of operator co_await, building
of await_* calls, and AST representation for same.

llvm-svn: 251387
2015-10-27 06:02:45 +00:00
Richard Smith 9be594e36d [coroutines] Add overloaded unary 'operator co_await'.
llvm-svn: 250991
2015-10-22 05:12:22 +00:00
Richard Smith d784e6893c PR14858: Initial support for proper sizeof... handling within alias templates.
This doesn't quite get alias template equivalence right yet, but handles the
egregious cases where we would silently give the wrong answers.

llvm-svn: 248431
2015-09-23 21:41:42 +00:00
Alexey Bader bdf7c846f9 Run clang-format to unify the switch statement style as suggest here: http://reviews.llvm.org/D12855#246073.
NFC.

llvm-svn: 247678
2015-09-15 12:18:29 +00:00
Alexey Bader 9c8453fb4b [OpenCL] Add new types for OpenCL 2.0.
Patch by Pedro Ferreira.
Reviewers: pekka.jaaskelainen
Differential Revision: http://reviews.llvm.org/D12855

llvm-svn: 247676
2015-09-15 11:18:52 +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
Alexey Bataev 1a3320e463 [OPENMP 4.0] Initial support for array sections.
Adds parsing/sema analysis/serialization/deserialization for array sections in OpenMP constructs (introduced in OpenMP 4.0).
Currently it is allowed to use array sections only in OpenMP clauses that accepts list of expressions.
Differential Revision: http://reviews.llvm.org/D10732

llvm-svn: 245937
2015-08-25 14:24:04 +00:00
Yaron Keren 556b21aa10 Remove and forbid raw_svector_ostream::flush() calls.
After r244870 flush() will only compare two null pointers and return,
doing nothing but wasting run time. The call is not required any more
as the stream and its SmallString are always in sync.

Thanks to David Blaikie for reviewing.

llvm-svn: 244928
2015-08-13 18:12:56 +00:00
Peter Collingbourne eeebc41b58 AST: Implement mangling support for function types without a prototype.
Function types without prototypes can arise when mangling a function type
within an overloadable function in C. We mangle these as the absence of
any parameter types (not even an empty parameter list).

Differential Revision: http://reviews.llvm.org/D11848

llvm-svn: 244374
2015-08-07 23:25:47 +00:00
Benjamin Kramer c9ba1bd20a [AST] Really allocate a SmallVector to the right size.
set_size only resets the end pointer and asserts if it is used to grow
the buffer. This would crash when mangling a float with more than 80 bits,
add a test with a ppc double double (128 bits).

Found by inspection.

llvm-svn: 243979
2015-08-04 13:34:50 +00:00
Douglas Gregor ab209d83be Implement the Objective-C __kindof type qualifier.
The __kindof type qualifier can be applied to Objective-C object
(pointer) types to indicate id-like behavior, which includes implicit
"downcasting" of __kindof types to subclasses and id-like message-send
behavior. __kindof types provide better type bounds for substitutions
into unspecified generic types, which preserves more type information.

llvm-svn: 241548
2015-07-07 03:58:42 +00:00
Alexey Bataev 0039651304 [OPENMP] Introduced type trait "__builtin_omp_required_simd_align" for default simd alignment.
Adds type trait "__builtin_omp_required_simd_align" after discussions here http://reviews.llvm.org/D9894
Differential Revision: http://reviews.llvm.org/D10597

llvm-svn: 241237
2015-07-02 03:40:19 +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
Peter Collingbourne d954601f63 CFI: Implement bitset emission for the Microsoft ABI.
Clang's control flow integrity implementation works by conceptually attaching
"tags" (in the form of bitset entries) to each virtual table, identifying
the names of the classes that the virtual table is compatible with. Under
the Itanium ABI, it is simple to assign tags to virtual tables; they are
simply the address points, which are available via VTableLayout. Because any
overridden methods receive an entry in the derived class's virtual table,
a check for an overridden method call can always be done by checking the
tag of whichever derived class overrode the method call.

The Microsoft ABI is a little different, as it does not directly use address
points, and overrides in a derived class do not cause new virtual table entries
to be added to the derived class; instead, the slot in the base class is
reused, and the compiler needs to adjust the this pointer at the call site
to (generally) the base class that initially defined the method. After the
this pointer has been adjusted, we cannot check for the derived class's tag,
as the virtual table may not be compatible with the derived class. So we
need to determine which base class we have been adjusted to.

Specifically, at each call site, we use ASTRecordLayout to identify the most
derived class whose virtual table is laid out at the "this" pointer offset
we are using to make the call, and check the virtual table for that tag.

Because address point information is unavailable, we "reconstruct" it as
follows: any virtual tables we create for a non-derived class receive a tag
for that class, and virtual tables for a base class inside a derived class
receive a tag for the base class, together with tags for any derived classes
which are laid out at the same position as the derived class (and therefore
have compatible virtual tables).

Differential Revision: http://reviews.llvm.org/D10520

llvm-svn: 240117
2015-06-19 02:30:43 +00:00