Commit Graph

129 Commits

Author SHA1 Message Date
Hans Wennborg 853ae94660 Start adding support for dllimport/dllexport on classes (PR11170)
This implements the central part of support for dllimport/dllexport on
classes: allowing the attribute on class declarations, inheriting it
to class members, and forcing emission of exported members. It's based
on Nico Rieck's patch from http://reviews.llvm.org/D1099.

This patch doesn't propagate dllexport to bases that are template
specializations, which is an interesting problem. It also doesn't
look at the rules when redeclaring classes with different attributes,
I'd like to do that separately.

Differential Revision: http://reviews.llvm.org/D3877

llvm-svn: 209908
2014-05-30 16:59:42 +00:00
Hans Wennborg 905f806098 Fix some misplaced spaces around 'override'
llvm-svn: 209588
2014-05-24 20:18:32 +00:00
Reid Kleckner 563f0e852c Use comdats to avoid double initialization of weak data
Initializers of global data that can appear multiple TUs (static data
members of class templates or __declspec(selectany) data) are now in a
comdat group keyed on the global variable being initialized.  On
non-Windows platforms, this is a code size and startup time
optimization.  On Windows, this is necessary for ABI compatibility with
MSVC.

Fixes PR16959.

Reviewers: rsmith

Differential Revision: http://reviews.llvm.org/D3811

llvm-svn: 209555
2014-05-23 21:13:45 +00:00
Warren Hunt 5c2b4ea662 [MS-ABI] Implements MS-compatible RTTI
Enables the emission of MS-compatible RTTI data structures for use with 
typeid, dynamic_cast and exceptions.  Does not implement dynamic_cast 
or exceptions.  As an artiface, typeid works in some cases but proper 
support an testing will coming in a subsequent patch.

majnemer has fuzzed the results.  Test cases included.

Differential Revision: http://reviews.llvm.org/D3833

llvm-svn: 209523
2014-05-23 16:07:43 +00:00
Craig Topper 8a13c4180e [C++11] Use 'nullptr'. CodeGen edition.
llvm-svn: 209272
2014-05-21 05:09:00 +00:00
Reid Kleckner 966abe7614 MS ABI: Use musttail for thunk IR generation
This allows us to perfectly forward non-trivial arguments that use
inalloca.

We still can't forward non-trivial arguments through thunks when we have
a covariant return type with a non-trivial adjustment.  This would
require emitting an extra copy, which is non-conforming anyway.

llvm-svn: 208927
2014-05-15 23:01:46 +00:00
Reid Kleckner cf87e10f9d Don't copy objects with trivial, deleted copy ctors
This affects both the Itanium and Microsoft C++ ABIs.

This is in anticipation of a change to the Itanium C++ ABI, and should
match GCC's current behavior.  The new text will likely be:

"""
Pass an object of class type by value if every copy constructor and
move constructor is deleted or trivial and at least one of them is not
deleted, and the destructor is trivial.
"""
http://sourcerytools.com/pipermail/cxx-abi-dev/2014-May/002728.html

On x86 Windows, we can mostly use the same logic, where we use inalloca
instead of passing by address.  However, on Win64, there are register
parameters, and we have to do what MSVC does.  MSVC ignores the presence
of non-trivial move constructors and only considers the presence of
non-trivial or deleted copy constructors.  If a non-trivial or deleted
copy ctor is present, it passes the argument indirectly.

This change fixes bugs and makes us more ABI compatible with both GCC
and MSVC.

Fixes PR19668.

Reviewers: rsmith

Differential Revision: http://reviews.llvm.org/D3660

llvm-svn: 208786
2014-05-14 16:02:09 +00:00
Reid Kleckner 40ca913727 Push record return type classification into CGCXXABI
In the Microsoft C++ ABI, instance methods always return records
indirectly via the second hidden parameter.  This was implemented in
X86_32ABIInfo, but not WinX86_64ABIInfo.

Rather than exposing a handful of boolean methods in the CGCXXABI
interface, we can expose a single method that applies C++ ABI return
value classification rules.

llvm-svn: 208733
2014-05-13 22:05:45 +00:00
Reid Kleckner 37abaca3c2 MS ABI: Pass 'sret' as the second parameter of instance methods
Summary:
MSVC always passes 'sret' after 'this', unlike GCC.  This required
changing a number of places in Clang that assumed the sret parameter was
always first in LLVM IR.

This fixes win64 MSVC ABI compatibility for methods returning structs.

Reviewers: rsmith, majnemer

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D3618

llvm-svn: 208458
2014-05-09 22:46:15 +00:00
Reid Kleckner e39ee21551 MS ABI x64: Pass small objects with dtors but no copy ctors directly
Passing objects directly (in registers or memory) creates a second copy
of the object in the callee.  The callee always destroys its copy, but
we also have to destroy any temporary created in the caller.  In other
words, copy elision of these kinds of objects is impossible.

Objects larger than 8 bytes with non-trivial dtors and trivial copy
ctors are still passed indirectly, and we can still elide copies of
them.

Fixes PR19640.

llvm-svn: 207889
2014-05-03 00:33:28 +00:00
Reid Kleckner 34a38d8efb MS ABI: Fix logic bug in member pointer null test code
This code is trying to test if the pointer is *not* null.  Therefore we
should use 'or' instead of 'and' to combine the results of 'icmp ne'.
This logic is consistent with the general member pointer comparison code
in EmitMemberPointerComparison.

llvm-svn: 207815
2014-05-02 00:05:16 +00:00
Reid Kleckner e9591b33e2 MS ABI: Use a different guard variable for each weak global
We were using the same guard variable and failing to initialize the
second global.

Clang is still not MS ABI compatible in this area.  Fixing that is
PR16959, which will require LLVM changes to @llvm.global_ctors.

llvm-svn: 207008
2014-04-23 18:22:11 +00:00
Timur Iskhodzhanov f1749427c5 Fix PR19104: Incorrect handling of non-virtual calls of virtual methods
Reviewed at http://llvm-reviews.chandlerc.com/D3054

llvm-svn: 203949
2014-03-14 17:43:37 +00:00
Aaron Ballman 445a939db8 [C++11] Replacing CXXRecordDecl iterators vbases_begin() and vbases_end() with iterator_range vbases(). Updating all of the usages of the iterators with range-based for loops.
llvm-svn: 203808
2014-03-13 16:15:17 +00:00
Aaron Ballman 574705ed7f [C++11] Replacing CXXRecordDecl iterators bases_begin() and bases_end() with iterator_range bases(). Updating all of the usages of the iterators with range-based for loops.
llvm-svn: 203803
2014-03-13 15:41:46 +00:00
Craig Topper 4f12f10de4 [C++11] Add 'override' keyword to virtual methods that override their base class.
llvm-svn: 203643
2014-03-12 06:41:41 +00:00
David Majnemer 2206bf5d5b [-cxx-abi microsoft] Implement local manglings accurately
Summary:
The MSVC ABI appears to mangle the lexical scope into the names of
statics.  Specifically, a counter is incremented whenever a scope is
entered where things can be declared in such a way that an ambiguity can
arise.  For example, a class scope inside of a class scope doesn't do
anything interesting because the nested class cannot collide with
another nested class.

There are problems with this scheme:
- It is unreliable. The counter is only incremented when a previously
  never encountered scope is entered.  There are cases where this will
  cause ambiguity amongst declarations that have the same name where one
  was introduced in a deep scope while the other was introduced right
  after in the previous lexical scope.
- It is wasteful.  Statements like: {{{{{{{ static int foo = a; }}}}}}}
  will make the mangling of "foo" larger than it need be because the
  scope counter has been incremented many times.

Because of these problems, and practical implementation concerns.  We
choose not to implement this scheme if the local static or local type
isn't visible.  The mangling of these declarations will look very
similar but the numbering will make far more sense, this scheme is
lifted from the Itanium ABI implementation.

Reviewers: rsmith, doug.gregor, rnk, eli.friedman, cdavis5x

Reviewed By: rnk

CC: cfe-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D2953

llvm-svn: 202951
2014-03-05 08:57:59 +00:00
Benjamin Kramer 867ea1d426 [C++11] Replace llvm::tie with std::tie.
llvm-svn: 202639
2014-03-02 13:01:17 +00:00
Reid Kleckner 9c6e9e313d MS ABI: Fix vftable mangling by using the vbtable name algorithm
Summary:
This merges VFPtrInfo and VBTableInfo into VPtrInfo, since they hold
almost the same information.  With that change, the vbtable mangling
code can easily be applied to vftable data and we magically get the
correct, unambiguous vftable names.

Fixes PR17748.

Reviewers: timurrrr, majnemer

CC: cfe-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D2893

llvm-svn: 202425
2014-02-27 19:40:09 +00:00
Reid Kleckner e4a5220d7c MS ABI: Include the vfptr offset in memptrs to virtual methods
Virtual methods expect 'this' to point to the vfptr containing the
virtual method, and this extends to virtual member pointer thunks.  The
relevant vfptr is always at offset zero on entry to the thunk, and no
this adjustment is needed.

Previously we would not include the vfptr adjustment in the member
pointer, and we'd look at the vfptr offset when loading from the vftable
in the thunk.

Fixes PR18917.

llvm-svn: 201835
2014-02-21 02:27:32 +00:00
David Majnemer 2b0d66df24 Sema: Do not assert when dereferencing member pointer using virtual inheritance with an incomplete class type
The MS ABI requires that we determine the vbptr offset if have a
virtual inheritance model.  Instead, raise an error pointing to the
diagnostic when this happens.

This fixes PR18583.

Differential Revision: http://llvm-reviews.chandlerc.com/D2842

llvm-svn: 201824
2014-02-20 23:22:07 +00:00
Reid Kleckner 0c12b36ebb MS ABI: Remove nv adjustment from direct vdtor calls and prologues
Summary:
Generally the vector deleting dtor, which we model as a vtable thunk,
takes care of non-virtual adjustment and delegates to the other
destructor variants.  The other non-complete destructor variants assume
that 'this' on entry points to the virtual base subobject that first
declared the virtual destructor.

We need to change the adjustment in both the prologue and the vdtor call
setup.

Reviewers: timurrrr

CC: cfe-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D2821

llvm-svn: 201612
2014-02-18 22:51:52 +00:00
John McCall 8f80a61914 Remove the -fhidden-weak-vtables -cc1 option. It was dead,
gross, and increasingly replaced through other mechanisms.

llvm-svn: 201011
2014-02-08 00:41:16 +00:00
Reid Kleckner 29d5999eb7 Remove unused variable to fix -Werror build
llvm-svn: 200861
2014-02-05 18:00:01 +00:00
Reid Kleckner 96f8f9339d MS ABI: Mangle member pointer template arguments
Member pointers are mangled as they would be represented at runtime.
They can be a single integer literal, single decl, or a tuple with some
more numbers tossed in.  With Clang today, most of those numbers will be
zero because we reject pointers to members of virtual bases.

This change required moving VTableContextBase ownership from
CodeGenVTables to ASTContext, because mangling now depends on vtable
layout.

I also hoisted the inheritance model helpers up to be inline static
methods of MSInheritanceAttr.  This makes the AST code that deals with
member pointers much more readable.

MSVC doesn't appear to have stable manglings of null member pointers:
- Null data memptrs in function templates have a mangling collision with
  the first field of a non-polymorphic single inheritance class.
- The mangling of null data memptrs changes if you add casts.
- Large null function memptrs in class templates crash MSVC.

Clang uses the class template mangling for null data memptrs and the
function template mangling for null function memptrs to deal with this.

Reviewers: majnemer

Differential Revision: http://llvm-reviews.chandlerc.com/D2695

llvm-svn: 200857
2014-02-05 17:27:08 +00:00
Reid Kleckner 314ef7bafd [ms-cxxabi] Use inalloca on win32 when passing non-trivial C++ objects
When a non-trivial parameter is present, clang now gathers up all the
parameters that lack inreg and puts them into a packed struct.  MSVC
always aligns each parameter to 4 bytes and no more, so this is a pretty
simple struct to lay out.

On win64, non-trivial records are passed indirectly.  Prior to this
change, clang was incorrectly using byval on win64.

I'm able to self-host a working clang with this change and additional
LLVM patches.

Reviewers: rsmith

Differential Revision: http://llvm-reviews.chandlerc.com/D2636

llvm-svn: 200597
2014-02-01 00:04:45 +00:00
David Majnemer 1cdd96d6ad Revert "Revert r199416, "MS ABI: Improve selection of an inheritance model""
This reverts commit r199475 (which reverted r199416) with fixes for the
breakages.

We wouldn't lock an inheritance model if we saw a pointer-to-member
formed as a result of the address-of operator.

llvm-svn: 199482
2014-01-17 09:01:00 +00:00
NAKAMURA Takumi 5c486cf3f3 Revert r199416, "MS ABI: Improve selection of an inheritance model"
It broke tests for targeting x86_64-pc-win32:

    Clang Tools :: clang-modernize/LoopConvert/array.cpp
    Clang :: CodeGenCXX/2010-05-10-Var-DbgInfo.cpp
    Clang :: CodeGenCXX/member-call-parens.cpp
    Clang :: CodeGenCXX/ptr-to-datamember.cpp
    Clang :: SemaTemplate/instantiate-function-1.cpp

llvm-svn: 199475
2014-01-17 07:33:47 +00:00
David Majnemer 37054dd4e7 MS ABI: Improve selection of an inheritance model
The MSVC ABI is rather finicky about the exact representation of it's
pointer-to-member representation.  The exact position of when and where
it will go with one representation versus another appears to be when it
desires the pointer-to-member to be complete.

To properly implement this in clang, do several things:
- Give up on tracking the polymorphic nature of the class.  It isn't
  useful to Sema and is only pertinent when choosing CodeGen-time
  details like whether the field-offset can be 0 instead of -1.
- Insist on locking-in the inheritance model when we ask our
  pointer-to-member type to be complete.  From there, grab the
  underlying CXXRecordDecl and try to make *that* complete.  Once we've
  done this, we can calculate it's inheritance model and apply it using
  an attribute.

N.B. My first bullet point is a lie.  We will eventually care about the
specifics of whether or not a CXXRecordDecl is or is not polymorphic
because MSVC compatible mangling of such things depends on it.  However,
I believe we will handle this in a rather different way.

llvm-svn: 199416
2014-01-16 20:05:57 +00:00
Reid Kleckner 5b1b5d5123 [ms-abi] Remove duplicated vbptr offset code
Record layout will tell us the offset of a shared vbptr inside a
non-virtual base.

No functionality change.

llvm-svn: 199171
2014-01-14 00:50:39 +00:00
Chandler Carruth 5553d0d4ca Sort all the #include lines with LLVM's utils/sort_includes.py which
encodes the canonical rules for LLVM's style. I noticed this had drifted
quite a bit when cleaning up LLVM, so wanted to clean up Clang as well.

llvm-svn: 198686
2014-01-07 11:51:46 +00:00
Reid Kleckner 5f08094106 [ms-cxxabi] Improve vbtable name mangling accuracy
Summary:
This makes us more compatible with MSVC 2012+ and fixes PR17748 where we
would give two tables the same name.

Rather than doing a fresh depth-first traversal of the inheritance graph
for every record's vbtables, now we memoize vbtable paths for each
record.  By doing memoization, we end up considering virtual bases of
subobjects that come later in the depth-first traversal.  Where
previously we would have ignored a virtual base that we'd already seen,
we now consider it for name mangling purposes without emitting a
duplicate vbtable for it.

Reviewers: majnemer

CC: cfe-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D2509

llvm-svn: 198462
2014-01-03 23:42:00 +00:00
Reid Kleckner b0c246e25e Remove unused variable to fix clang warning
llvm-svn: 198382
2014-01-03 00:36:32 +00:00
Reid Kleckner b40a27dad8 [ms-cxxabi] Move VBTableBuilder from CodeGen over to AST/VTableBuilder.cpp
Summary:
No functionality change.

This code should live here long-term because we should be able to use it
to compute correct vftable names.

It turns out that the most natural way to implement the naming algorithm
is to use a caching layer similar to what we already have for virtual
table info in VTableContext.  Subsequent changes will take advantage of
this to fix PR17748, where we have a vbtable name collision.

Reviewers: majnemer

CC: cfe-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D2499

llvm-svn: 198380
2014-01-03 00:14:35 +00:00
Reid Kleckner 89077a1b00 [ms-cxxabi] The 'most derived' ctor parameter usually comes last
Unlike Itanium's VTTs, the 'most derived' boolean or bitfield is the
last parameter for non-variadic constructors, rather than the second.
For variadic constructors, the 'most derived' parameter comes after the
'this' parameter.  This affects constructor calls and constructor decls
in a variety of places.

Reviewers: timurrrr

Differential Revision: http://llvm-reviews.chandlerc.com/D2405

llvm-svn: 197518
2013-12-17 19:46:40 +00:00
Reid Kleckner 6fe771ad9b Move C++ destructor emission into CGCXXABI
No functionality change.  Only Itanium C++ destructors have implicit VTT
parameters.

llvm-svn: 197194
2013-12-13 00:53:54 +00:00
David Majnemer 2a81645de5 [-cxx-abi microsoft] Mangle large integral constants correctly
Testing has revealed that large integral constants (i.e. > INT64_MAX)
are always mangled as-if they are negative, even in places where it
would not make sense for them to be negative (like non-type template
parameters of type unsigned long long).

To address this, we change the way we model number mangling: always
mangle as-if our number is an int64_t.  This should result in correct
results when we have large unsigned numbers.

N.B.  Bizarrely, things that are 32-bit displacements like vbptr offsets
are mangled as-if they are unsigned 32-bit numbers.  This is a pretty
egregious waste of space, it would be a 4x savings if we could mangle it
like a signed 32-bit number.  Instead, we explicitly cast these
displacements to uint32_t and let the mangler proceed.

llvm-svn: 196771
2013-12-09 10:44:32 +00:00
Reid Kleckner ae9451218f [ms-cxxabi] bitcast to i8* to deref a data member pointer
This was causing us to miscompile
llvm::SymbolTableListTraits::getListOwner(), which uses data member
pointers.

llvm-svn: 196545
2013-12-05 22:44:07 +00:00
Alp Toker f6a24ce40f Fix a tranche of comment, test and doc typos
llvm-svn: 196510
2013-12-05 16:25:25 +00:00
Hans Wennborg feedf8515b [-cxx-abi microsoft] Emit linkonce_odr definitions for declarations of static data members with inline initializers (PR17689)
This makes Clang emit a linkonce_odr definition for 'val' in the code below,
to be compatible with MSVC-compiled code:

  struct Foo {
    static const int val = 1;
  };

Differential Revision: http://llvm-reviews.chandlerc.com/D2233

llvm-svn: 195283
2013-11-21 00:15:56 +00:00
Alp Toker 3aa8779ca2 Remove an unused local from r194827
llvm-svn: 194835
2013-11-15 18:09:28 +00:00
Hans Wennborg 88497d6157 [-cxx-abi microsoft] Emit thunks for pointers to virtual member functions
Instead of storing the vtable offset directly in the function pointer and
doing a branch to check for virtualness at each call site, the MS ABI
generates a thunk for calling the function at a specific vtable offset,
and puts that in the function pointer.

This patch adds support for emitting such thunks. However, it doesn't support
pointers to virtual member functions that are variadic, have an incomplete
aggregate return type or parameter, or are overriding a function in a virtual
base class.

Differential Revision: http://llvm-reviews.chandlerc.com/D2104

llvm-svn: 194827
2013-11-15 17:24:45 +00:00
Timur Iskhodzhanov 4ddf59201a No need to use CGM.getCXXABI() from CXXABI
llvm-svn: 194584
2013-11-13 16:03:43 +00:00
Timur Iskhodzhanov 9e7f505515 Minor refinement of VTableBuilder.h: fix wrong indentation, rename a struct field with a more appropriate name
llvm-svn: 194202
2013-11-07 13:34:02 +00:00
Timur Iskhodzhanov 053142a90d Fix PR17738 - add support for vtordisp thunks when using -cxx-abi microsoft
llvm-svn: 194132
2013-11-06 06:24:31 +00:00
Timur Iskhodzhanov 5877663622 Fix vbtable indices when a class shares the vbptr with a non-virtual base
llvm-svn: 194082
2013-11-05 15:54:58 +00:00
Timur Iskhodzhanov 0201432a5e Make thunk this/return adjustment ABI-specific. Also, fix the return adjustment when using -cxx-abi microsoft
Reviewed at http://llvm-reviews.chandlerc.com/D2026

llvm-svn: 193679
2013-10-30 11:55:43 +00:00
Timur Iskhodzhanov 07e6eff8fa Fix the inconsistent order of parameters in the GetVBaseOffsetFromVBPtr definition and declaration
llvm-svn: 193505
2013-10-27 17:10:27 +00:00
Timur Iskhodzhanov 827365ea8f Use GEPs correctly when adjusting this in MicrosoftCXXABI
Reviewed at http://llvm-reviews.chandlerc.com/D1977

llvm-svn: 193176
2013-10-22 18:15:24 +00:00
Reid Kleckner 5a823d5f05 [ms-cxxabi] Error out on virtual function memptrs
These are uncommon and this is better than miscompiling.

llvm-svn: 192923
2013-10-17 21:30:27 +00:00