Commit Graph

1344 Commits

Author SHA1 Message Date
Erich Keane bd2197c0c1 Fix ICE when __has_unqiue_object_representations called with invalid decl
llvm-svn: 320489
2017-12-12 16:02:06 +00:00
Sven van Haastregt 3bb7eaf72e [OpenCL] Fix layering violation by getOpenCLTypeAddrSpace
Commit 7ac28eb0a5 / r310911 ("[OpenCL] Allow targets to select address
space per type", 2017-08-15) made Basic depend on AST, introducing a
circular dependency.  Break this dependency by adding the
OpenCLTypeKind enum in Basic and map from AST types to this enum in
ASTContext.

Differential Revision: https://reviews.llvm.org/D40838

llvm-svn: 319883
2017-12-06 10:11:28 +00:00
Aaron Ballman c351fba69e Now that C++17 is official (https://www.iso.org/standard/68564.html), start changing the C++1z terminology over to C++17. NFC intended, these are all mechanical changes.
llvm-svn: 319688
2017-12-04 20:27:34 +00:00
Erich Keane 8a6b740995 Fix __has_unique_object_representations implementation
As rsmith pointed out, the original implementation of this intrinsic
missed a number of important situations.  This patch fixe a bunch of
shortcomings and implementation details to make it work correctly.

Differential Revision: https://reviews.llvm.org/D39347

llvm-svn: 319446
2017-11-30 16:37:02 +00:00
Serge Pavlov 03e672ccab Refactor functions PrintTemplateArgumentList
These functions were defined as static members of TemplateSpecializationType.
Now they are moved to namespace level. Previously there were different
implementations for lists containing TemplateArgument and TemplateArgumentLoc,
now these implementations share the same code.

This change is a result of refactoring patch D40508. NFC.

llvm-svn: 319178
2017-11-28 16:14:14 +00:00
Eugene Zelenko 5e5e564ca6 [AST] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).
llvm-svn: 318888
2017-11-23 01:20:07 +00:00
Richard Smith e2467b7aed PR22763: if a defaulted (non-user-provided) special member function is
explicitly instantiated, still emit it with each use.

We don't emit a definition of the member with an explicit instantiation
definition (and indeed it appears that we're not allowed to, since an explicit
instantiation definition does not constitute an odr-use and only odr-use
permits definition for defaulted special members). So we still need to emit a
weak definition with each use.

This also makes defaulted-in-class declarations behave more like
implicitly-declared special members, which matches their design intent.
And it matches the way this problem was solved in GCC.

llvm-svn: 318474
2017-11-16 23:54:56 +00:00
Erich Keane a957ffbce3 Add default calling convention support for regcall.
Added support for regcall as default calling convention. Also added code to
exclude main when applying default calling conventions.

Patch-By: eandrews

Differential Revision: https://reviews.llvm.org/D39210

llvm-svn: 317268
2017-11-02 21:08:00 +00:00
Erich Keane 5759fa798b Correct behavior of fastcall when default CC is set.
Fastcall doesn't support variadic function calls, so
setting the default calling convention to Fastcall would
result in incorrect code being emitted for these conditions.

This patch adds a 'variadic' test to the default calling conv
test, as well as fixes the behavior of fastcall.

llvm-svn: 316528
2017-10-24 23:12:01 +00:00
Richard Smith 8910fe699e For better compatibility with C++11 and C++14, emit a nondiscardable definition
of a static constexpr data member if it's defined 'constexpr' out of line, not
only if it's defined 'constexpr' in the class.

llvm-svn: 316310
2017-10-23 03:58:34 +00:00
Alexander Richardson 6d989436d0 Convert clang::LangAS to a strongly typed enum
Summary:
Convert clang::LangAS to a strongly typed enum

Currently both clang AST address spaces and target specific address spaces
are represented as unsigned which can lead to subtle errors if the wrong
type is passed. It is especially confusing in the CodeGen files as it is
not possible to see what kind of address space should be passed to a
function without looking at the implementation.
I originally made this change for our LLVM fork for the CHERI architecture
where we make extensive use of address spaces to differentiate between
capabilities and pointers. When merging the upstream changes I usually
run into some test failures or runtime crashes because the wrong kind of
address space is passed to a function. By converting the LangAS enum to a
C++11 we can catch these errors at compile time. Additionally, it is now
obvious from the function signature which kind of address space it expects.

I found the following errors while writing this patch:

- ItaniumRecordLayoutBuilder::LayoutField was passing a clang AST address
  space to  TargetInfo::getPointer{Width,Align}()
- TypePrinter::printAttributedAfter() prints the numeric value of the
  clang AST address space instead of the target address space.
  However, this code is not used so I kept the current behaviour
- initializeForBlockHeader() in CGBlocks.cpp was passing
  LangAS::opencl_generic to TargetInfo::getPointer{Width,Align}()
- CodeGenFunction::EmitBlockLiteral() was passing a AST address space to
  TargetInfo::getPointerWidth()
- CGOpenMPRuntimeNVPTX::translateParameter() passed a target address space
  to Qualifiers::addAddressSpace()
- CGOpenMPRuntimeNVPTX::getParameterAddress() was using
  llvm::Type::getPointerTo() with a AST address space
- clang_getAddressSpace() returns either a LangAS or a target address
  space. As this is exposed to C I have kept the current behaviour and
  added a comment stating that it is probably not correct.

Other than this the patch should not cause any functional changes.

Reviewers: yaxunl, pcc, bader

Reviewed By: yaxunl, bader

Subscribers: jlebar, jholewinski, nhaehnle, Anastasia, cfe-commits

Differential Revision: https://reviews.llvm.org/D38816

llvm-svn: 315871
2017-10-15 18:48:14 +00:00
Yaxun Liu b7318e02c1 [OpenCL] Add LangAS::opencl_private to represent private address space in AST
Currently Clang uses default address space (0) to represent private address space for OpenCL
in AST. There are two issues with this:

Multiple address spaces including private address space cannot be diagnosed.
There is no mangling for default address space. For example, if private int* is emitted as
i32 addrspace(5)* in IR. It is supposed to be mangled as PUAS5i but it is mangled as
Pi instead.

This patch attempts to represent OpenCL private address space explicitly in AST. It adds
a new enum LangAS::opencl_private and adds it to the variable types which are implicitly
private:

automatic variables without address space qualifier

function parameter

pointee type without address space qualifier (OpenCL 1.2 and below)

Differential Revision: https://reviews.llvm.org/D35082

llvm-svn: 315668
2017-10-13 03:37:48 +00:00
Benjamin Kramer c24fb0718d Remove unused variables. No functionality change.
llvm-svn: 315196
2017-10-08 21:23:02 +00:00
Andrew Gozillon 572bbb0754 Dependent Address Space Support
This patch relates to: https://reviews.llvm.org/D33666 This adds support
for template parameters to be passed to the address_space attribute. 
The main goal is to add further flexibility to the attribute and allow 
for it to be used easily with templates.

The main additions are a new type (DependentAddressSpaceType) alongside 
its TypeLoc and its mangling. As well as the logic required to support 
dependent address spaces which mainly resides in TreeTransform.h and 
SemaType.cpp.

llvm-svn: 314649
2017-10-02 06:25:51 +00:00
Alexander Shaposhnikov 195b25cf3c [clang] Add getUnsignedPointerDiffType method
C11 standard refers to the unsigned counterpart of the type ptrdiff_t 
in the paragraph 7.21.6.1p7 where it defines the format specifier %tu.
In Clang (in PrintfFormatString.cpp, lines 508-510) there is a FIXME for this case,
in particular, Clang didn't diagnose %tu issues at all, i.e.
it didn't emit any warnings on the code printf("%tu", 3.14).
In this diff we add a method getUnsignedPointerDiffType for getting the corresponding type
similarly to how it's already done in the other analogous cases (size_t, ssize_t, ptrdiff_t etc)
and fix -Wformat diagnostics for %tu plus the emitted fix-it as well.

Test plan: make check-all

Differential revision: https://reviews.llvm.org/D38270

llvm-svn: 314470
2017-09-28 23:11:31 +00:00
Akira Hatanaka 98a49337be Add support for attribute 'noescape'.
The attribute informs the compiler that the annotated pointer parameter
of a function cannot escape and enables IRGen to attach attribute
'nocapture' to parameters that are annotated with the attribute. That is
the only optimization that currently takes advantage of 'noescape', but
there are other optimizations that will be added later that improves
IRGen for ObjC blocks.

This recommits r313722, which was reverted in r313725 because clang
couldn't build compiler-rt. It failed to build because there were
function declarations that were missing 'noescape'. That has been fixed
in r313929.

rdar://problem/19886775

Differential Revision: https://reviews.llvm.org/D32210

llvm-svn: 313945
2017-09-22 00:41:05 +00:00
Akira Hatanaka 30c93dba5b Revert "Add support for attribute 'noescape'."
This reverts commit r313722.

It looks like compiler-rt/lib/tsan/rtl/tsan_libdispatch_mac.cc cannot be
compiled because some of the functions declared in the file do not match
the ones in the SDK headers (which are annotated with 'noescape').

llvm-svn: 313725
2017-09-20 06:55:43 +00:00
Akira Hatanaka e974479fa5 Add support for attribute 'noescape'.
The attribute informs the compiler that the annotated pointer parameter
of a function cannot escape and enables IRGen to attach attribute
'nocapture' to parameters that are annotated with the attribute. That is
the only optimization that currently takes advantage of 'noescape', but
there are other optimizations that will be added later that improves
IRGen for ObjC blocks.

rdar://problem/19886775

Differential Revision: https://reviews.llvm.org/D32210

llvm-svn: 313722
2017-09-20 06:32:45 +00:00
Akira Hatanaka 1b9418e163 Revert "Add support for attribute 'noescape'."
This reverts r313717.

I closed the wrong phabricator review.

llvm-svn: 313721
2017-09-20 06:27:39 +00:00
Akira Hatanaka fc587e6a57 Add support for attribute 'noescape'.
The attribute informs the compiler that the annotated pointer parameter
of a function cannot escape and enables IRGen to attach attribute
'nocapture' to parameters that are annotated with the attribute. That is
the only optimization that currently takes advantage of 'noescape', but
there are other optimizations that will be added later that improves
IRGen for ObjC blocks.

rdar://problem/19886775

Differential Revision: https://reviews.llvm.org/D32520

llvm-svn: 313720
2017-09-20 06:22:51 +00:00
Sjoerd Meijer cc623ad071 Recommit "Add _Float16 as a C/C++ source language type"
This is a recommit of r312781; in some build configurations
variable names are omitted, so changed the new regression
test accordingly.

llvm-svn: 312794
2017-09-08 15:15:00 +00:00
Sjoerd Meijer 9aeedde7ff Revert "Add _Float16 as a C/C++ source language type"
The clang-with-lto-ubuntu bot didn't like the new regression
test, revert while I investigate the issue.

llvm-svn: 312784
2017-09-08 10:20:52 +00:00
Sjoerd Meijer ab36f33db8 Add _Float16 as a C/C++ source language type
This adds _Float16 as a source language type, which is a 16-bit floating point
type defined in C11 extension ISO/IEC TS 18661-3.

In follow up patches documentation and more tests will be added.

Differential Revision: https://reviews.llvm.org/D33719

llvm-svn: 312781
2017-09-08 09:42:32 +00:00
Richard Smith a465362d77 [modules ts] Emit global variables in a module interface unit as part of that unit, not in importers.
llvm-svn: 312665
2017-09-06 20:01:14 +00:00
Sven van Haastregt efb4d4c78c [OpenCL] Allow targets to select address space per type
Generalize getOpenCLImageAddrSpace into getOpenCLTypeAddrSpace, such
that targets can select the address space per type.

No functional changes intended.

Initial patch by Simon Perretta.

Differential Revision: https://reviews.llvm.org/D33989

llvm-svn: 310911
2017-08-15 09:38:18 +00:00
Yaxun Liu 39195062c2 Add OpenCL 2.0 atomic builtin functions as Clang builtin
OpenCL 2.0 atomic builtin functions have a scope argument which is ideally
represented as synchronization scope argument in LLVM atomic instructions.

Clang supports translating Clang atomic builtin functions to LLVM atomic
instructions. However it currently does not support synchronization scope
of LLVM atomic instructions. Without this, users have to use LLVM assembly
code to implement OpenCL atomic builtin functions.

This patch adds OpenCL 2.0 atomic builtin functions as Clang builtin
functions, which supports generating LLVM atomic instructions with
synchronization scope operand.

Currently only constant memory scope argument is supported. Support of
non-constant memory scope argument will be added later.

Differential Revision: https://reviews.llvm.org/D28691

llvm-svn: 310082
2017-08-04 18:16:31 +00:00
Alexander Shaposhnikov 1e898d911c [clang] Add getSignedSizeType method
C11 standard refers to the signed counterpart of the type size_t in
the paragraph 7.21.6.1 where it defines d, i, o, u, x, or x conversion specifiers
(in printf format string).
In Clang there is a FIXME (in lib/Analysis/PrintfFormatString.cpp) for this case
(which is not handled correctly at the moment).
This diff adds getSignedSizeType method to TargetInfo and exposes it 
in ASTContext similarly to how it is done for getSizeType.
lib/Analysis/PrintfFormatString.cpp will be changed in a separate commit.

Differential revision: https://reviews.llvm.org/D35378

Test plan: make check-all

llvm-svn: 308037
2017-07-14 17:30:14 +00:00
Eric Christopher 50daf5fbbb IsSpecialLong was only ever set in release mode as all of the uses are in asserts. Wrap in ifndef NDEBUG.
llvm-svn: 307594
2017-07-10 21:28:54 +00:00
Akira Hatanaka 4b1c48441d [CodeGen][ObjC] Fix GNU's encoding of bit-field ivars.
According to the documentation, when encoding a bit-field, GNU runtime
needs its starting position in addition to its type and size.

https://gcc.gnu.org/onlinedocs/gcc/Type-encoding.html

Prior to r297702, the starting position information was not being
encoded, which is incorrect, and after r297702, an assertion started to
fail because an ObjCIvarDecl was being passed to a function expecting a
FieldDecl.

This commit moves LookupFieldBitOffset to ASTContext and uses the
function to encode the starting position of bit-fields.

llvm-svn: 306364
2017-06-27 04:34:04 +00:00
Richard Smith 90dc525472 PR33552: Distinguish between declarations that are owned by no module and
declarations that are owned but unconditionally visible.

This allows us to set declarations as visible even if they have a local owning
module, without losing information. In turn, that means that our Objective-C
support can keep on incorrectly assuming the "hidden" bit on the declaration is
the whole story with regard to name visibility. This will also be useful once
we support the C++ Modules TS export semantics.

Objective-C name visibility is still incorrect in any case where the "hidden"
bit is not the complete story: for instance, in Objective-C++ the set of
visible categories will be wrong during template instantiation, and with local
submodule visibility enabled it will be wrong when building modules. Fixing that
will require a major overhaul of how visibility is handled for Objective-C (and
particularly for categories).

llvm-svn: 306075
2017-06-23 01:04:34 +00:00
Bruno Cardoso Lopes afa47c91ce Support MS builtins using 'long' on LP64 platforms
This allows for -fms-extensions to work the same on LP64. For example,
_BitScanReverse is expected to be 32-bit, matching Windows/LLP64, even
though long is 64-bit on x86_64 Darwin or Linux (LP64).

Implement this by adding a new character code 'N', which is 'int' if
the target is LP64 and the same 'L' otherwise

Differential Revision: https://reviews.llvm.org/D34377

rdar://problem/32599746

llvm-svn: 305875
2017-06-21 02:20:46 +00:00
Duncan P. N. Exon Smith eae8caa3bb AST: Add missing break at end of switch
llvm-svn: 305418
2017-06-14 21:26:31 +00:00
George Burgess IV b5fe855dfb [Sema] Use the right FoldingSet.
We were doing FindNodeOrInsertPos on SubstTemplateTypeParmPackTypes, so
we should presumably be inserting into SubstTemplateTypeParmPackTypes.

Looks like the FoldingSet API can be tweaked a bit so that we can catch
things like this at compile-time. I'll look into that shortly.

I'm unsure of how to test this; suggestions welcome.

Thanks to Vladimir Voskresensky for bringing this up!

llvm-svn: 305207
2017-06-12 17:44:30 +00:00
Anastasia Stulova b3398936ab [OpenCL] Fix pipe size in TypeInfo.
Pipes are now the size of pointers rather than the size
of the type that they contain.

Patch by Simon Perretta!

Differential Revision: https://reviews.llvm.org/D33597

llvm-svn: 304708
2017-06-05 11:27:03 +00:00
Galina Kistanova f87496d107 Added LLVM_FALLTHROUGH to address warning: this statement may fall through. NFC.
llvm-svn: 304650
2017-06-03 06:31:42 +00:00
Yaxun Liu 6d96f16347 CodeGen: Cast alloca to expected address space
Alloca always returns a pointer in alloca address space, which may
be different from the type defined by the language. For example,
in C++ the auto variables are in the default address space. Therefore
cast alloca to the expected address space when necessary.

Differential Revision: https://reviews.llvm.org/D32248

llvm-svn: 303370
2017-05-18 18:51:09 +00:00
Oren Ben Simhon 318a6eae06 [X86] Support of no_caller_saved_registers attribute
Implements the Clang part for no_caller_saved_registers attribute as appears here: 
https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=5ed3cc7b66af4758f7849ed6f65f4365be8223be.

Differential Revision: https://reviews.llvm.org/D31871

llvm-svn: 301535
2017-04-27 12:01:00 +00:00
Gabor Horvath 10a837a27e Remove unnecessary condition as suggested by clang-tidy. NFC
Patch by: Gergely Angeli!

Differential Revision: https://reviews.llvm.org/D31938

llvm-svn: 300703
2017-04-19 15:11:10 +00:00
David Blaikie e6b7c28d17 Modular Codegen: Add/use a bit in serialized function definitions to track whether they are the subject of modular codegen
Some decls are created not where they are written, but in other module
files/users (implicit special members and function template implicit
specializations). To correctly identify them, use a bit next to the definition
to track the modular codegen property.

Discussed whether the module file bit could be omitted in favor of
reconstituting from the modular codegen decls list - best guess today is that
the efficiency improvement of not having to deserialize the whole list whenever
any function is queried by a module user is worth it for the small size
increase of this redundant (list + bit-on-def) representation.

Reviewers: rsmith

Differential Revision: https://reviews.llvm.org/D29901

llvm-svn: 299982
2017-04-11 20:46:34 +00:00
Yaxun Liu b34ec829be [OpenCL] Map default address space to alloca address space
For OpenCL, the private address space qualifier is 0 in AST. Before this change, 0 address space qualifier
is always mapped to target address space 0. As now target private address space is specified by
alloca address space in data layout, address space qualifier 0 needs to be mapped to alloca addr space specified by the data layout.

This change has no impact on targets whose alloca addr space is 0.

With contributions from Matt Arsenault, Tony Tye and Wen-Heng (Jack) Chung

Differential Revision: https://reviews.llvm.org/D31404

llvm-svn: 299965
2017-04-11 17:24:23 +00:00
Dean Michael Berris 835832d37a [XRay] Add -fxray-{always,never}-instrument= flags to clang
Summary:
The -fxray-always-instrument= and -fxray-never-instrument= flags take
filenames that are used to imbue the XRay instrumentation attributes
using a whitelist mechanism (similar to the sanitizer special cases
list). We use the same syntax and semantics as the sanitizer blacklists
files in the implementation.

As implemented, we respect the attributes that are already defined in
the source file (i.e. those that have the
[[clang::xray_{always,never}_instrument]] attributes) before applying
the always/never instrument lists.

Reviewers: rsmith, chandlerc

Subscribers: jfb, mgorny, cfe-commits

Differential Revision: https://reviews.llvm.org/D30388

llvm-svn: 299041
2017-03-30 00:29:36 +00:00
Chandler Carruth 45bbe0117b Revert r298491 and r298494 which changed Clang's handling of 'nonnull'
attributes.

These patches don't work because we can't currently access the parameter
information in a reliable way when building attributes. I thought this
would be relatively straightforward to fix, but it seems not to be the
case. Fixing this will requrie a substantial re-plumbing of machinery to
allow attributes to be handled in this location, and several other fixes
to the attribute machinery should probably be made at the same time. All
of this will make the patch .... substantially more complicated.

Reverting for now as there are active miscompiles caused by the current
version.

llvm-svn: 298695
2017-03-24 09:11:57 +00:00
Chandler Carruth 9b3607f0a6 [nonnull] Teach Clang to attach the nonnull LLVM attribute to
declarations and calls instead of just definitions, and then teach it to
*not* attach such attributes even if the source code contains them.

This follows the design direction discussed on cfe-dev here:
http://lists.llvm.org/pipermail/cfe-dev/2017-January/052066.html

The idea is that for C standard library builtins, even if the library
vendor chooses to annotate their routines with __attribute__((nonnull)),
we will ignore those attributes which pertain to pointer arguments that
have an associated size. This allows the widespread (and seemingly
reasonable) pattern of calling these routines with a null pointer and
a zero size. I have only done this for the library builtins currently
recognized by Clang, but we can now trivially add to this set. This will
be controllable with -fno-builtin if anyone should care to do so.

Note that this does *not* change the AST. As a consequence, warnings,
static analysis, and source code rewriting are not impacted.

This isn't even a regression on any platform as neither Clang nor LLVM
have ever put 'nonnull' onto these arguments for declarations. All this
patch does is enable it on other declarations while preventing us from
ever accidentally enabling it on these libc functions due to a library
vendor.

It will also allow any other libraries using this annotation to gain
optimizations based on the annotation even when only a declaration is
visible.

llvm-svn: 298491
2017-03-22 09:09:13 +00:00
Konstantin Zhuravlyov 9c1e310c16 Fix array sizes where address space is not yet known
For variables in generic address spaces, for example:

```
unsigned char V[6442450944];
...
```

the address space is not yet known when we get into
*getConstantArrayType*, it is 0. AMDGCN target's
address space 0 has 32 bits pointers, so when we
call *getPointerWidth* with 0, the array size is
trimmed to 32 bits, which is not right.

Differential Revision: https://reviews.llvm.org/D30845

llvm-svn: 298420
2017-03-21 18:55:39 +00:00
Anastasia Stulova 81a25e352f [OpenCL] Fix type compatibility check and generic AS mangling.
1. Reimplemented conditional operator so that it checks
compatibility of unqualified pointees of the 2nd and
the 3rd operands (C99, OpenCL v2.0 6.5.15).

Define QualTypes compatibility for OpenCL as following:

   - corresponding types are compatible (C99 6.7.3)
   - CVR-qualifiers are equal (C99 6.7.3)
   - address spaces are equal (implementation defined)

2. Added generic address space to Itanium mangling.

Review: D30037

Patch by Dmitry Borisenkov!

llvm-svn: 297468
2017-03-10 15:23:07 +00:00
Roger Ferrer Ibanez 3fa38a14ac Honor __unaligned in codegen for declarations and expressions
This patch honors the unaligned type qualifier (currently available through he
keyword __unaligned and -fms-extensions) in CodeGen. In the current form the
patch affects declarations and expressions. It does not affect fields of
classes.

Differential Revision: https://reviews.llvm.org/D30166

llvm-svn: 297276
2017-03-08 14:00:44 +00:00
Roger Ferrer Ibanez d93add34b7 Fix crash when an incorrect redeclaration only differs in __unaligned type-qualifier
Fix an assertion that is hit when a redeclaration with differing types only
differs in the unaligned type-qualifier.

Differential Revision: https://reviews.llvm.org/D29986

llvm-svn: 296099
2017-02-24 08:41:09 +00:00
Yaron Keren 4cd211b5de Remove superfluous initializer.
The following fully-covered switch either sets value to External or exits the function.

llvm-svn: 295839
2017-02-22 14:32:39 +00:00
Anastasia Stulova 58984e7087 [OpenCL] Correct ndrange_t implementation
Removed ndrange_t as Clang builtin type and added
as a struct type in the OpenCL header.

Use type name to do the Sema checking in enqueue_kernel
and modify IR generation accordingly.

Review: D28058

Patch by Dmitry Borisenkov!  
 

llvm-svn: 295311
2017-02-16 12:27:47 +00:00
Richard Smith 3291877656 [c++1z] Synthesize implicit deduction guides from constructors on demand. Rank
such guides below explicit ones, and ensure that references to the class's
template parameters are not treated as forwarding references.

We make a few tweaks to the wording in the current standard:
1) The constructor parameter list is copied faithfully to the deduction guide,
   without losing default arguments or a varargs ellipsis (which the standard
   wording loses by omission).
2) If the class template declares no constructors, we add a T() -> T<...> guide
   (which will only ever work if T has default arguments for all non-pack
   template parameters).
3) If the class template declares nothing that looks like a copy or move
   constructor, we add a T(T<...>) -> T<...> guide.
#2 and #3 follow from the "pretend we had a class type with these constructors"
philosophy for deduction guides.

llvm-svn: 295007
2017-02-14 00:25:28 +00:00