972 Commits

Author SHA1 Message Date
Richard Smith
51ec0cf4aa Factor out function to determine whether we're performing a template
instantiation.

In preparation for converting the template stack to a more general context
stack (so we can include context notes for other kinds of context).

llvm-svn: 295686
2017-02-21 01:17:38 +00:00
Richard Smith
bc491203c7 Add an explicit derived class of FunctionDecl to model deduction guides rather
than just treating them as FunctionDecls with a funny name.

No functionality change intended.

llvm-svn: 295491
2017-02-17 20:05:37 +00:00
Richard Smith
efa919ab07 Properly set up the DeclContext for parameters of implicit deduction guides;
this is needed for deferred instantiation of default arguments.

llvm-svn: 295379
2017-02-16 21:29:21 +00:00
Richard Smith
4e05eaa9e8 [c++1z] Diagnose non-deducible template parameters in deduction guide templates, per [temp.param]p11.
llvm-svn: 295264
2017-02-16 00:36:47 +00:00
Richard Smith
c27b3d7623 Canonicalize implicit deduction guide parameter types when forming a deduction
guide from a constructor.

The purpose of this change is to avoid triggering instantiation of the class
when substituting back into the deduction guide if it uses a typedef member.
We will still instantiate the class if the constructor (explicitly or
implicitly, directly or indirectly) uses the current instantiation in a way
that we can't canonicalize out, but that seems unavoidable.

llvm-svn: 295016
2017-02-14 01:49:59 +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
Richard Smith
278890f85b [c++1z] Enforce restriction that deduction guide is declared in the same scope as its template.
llvm-svn: 294778
2017-02-10 20:39:58 +00:00
Hubert Tong
5a8ec4e287 [Concepts] Class template associated constraints
Summary:
This adds associated constraints as a property of class templates.
An error is produced if redeclarations are not similarly constrained.

Reviewers: rsmith, faisalv, aaron.ballman

Reviewed By: rsmith

Subscribers: cfe-commits, nwilson

Differential Revision: https://reviews.llvm.org/D25674

llvm-svn: 294697
2017-02-10 02:46:19 +00:00
Richard Smith
19a311a483 Disallow explicit instantiation and explicit specialization for deduction guides.
llvm-svn: 294641
2017-02-09 22:47:51 +00:00
Richard Smith
f445f196ae Rename IsExplicitSpecialization -> IsMemberSpecialization when we're talking
about member specializations to avoid ambiguous and confusing terminology.

llvm-svn: 294622
2017-02-09 21:04:43 +00:00
Richard Smith
3411fbff0b Repoint 'missing typename' diagnostic to the location where 'typename' should be added.
llvm-svn: 293817
2017-02-01 21:41:18 +00:00
Richard Smith
62559bd7ce Fix hole in our enforcement of rule requiring 'typename' prior to a dependent
name. If the dependent name happened to end in a template-id (X<T>::Y<U>), we
would fail to notice that the 'typename' keyword is missing when resolving it
to a type.

It turns out that GCC has a similar bug. If this shows up in much real code, we
can easily downgrade this to an ExtWarn.

llvm-svn: 293815
2017-02-01 21:36:38 +00:00
Richard Smith
ee57984c11 Towards P0091R3: parsing support for class template argument deduction in typename-specifiers.
This reinstates r293455, reverted in r293455, with a fix for cv-qualifier
handling on dependent typename-specifiers.

llvm-svn: 293544
2017-01-30 20:39:26 +00:00
Sam McCall
4f53b51fe7 Revert r293455, which breaks v8 with a spurious error. Testcase added.
Summary: Revert r293455, which breaks v8 with a spurious error. Testcase added.

Reviewers: klimek

Subscribers: cfe-commits, rsmith

Differential Revision: https://reviews.llvm.org/D29271

llvm-svn: 293473
2017-01-30 10:44:11 +00:00
Richard Smith
c95726ea39 Towards P0091R3: parsing support for class template argument deduction in typename-specifiers.
llvm-svn: 293455
2017-01-30 04:38:28 +00:00
Richard Smith
fc6fca1cab When converting a template argument representing &array to an expression for a
pointer typed template parameter, form &array rather than an array-to-pointer
decay on array.

llvm-svn: 293350
2017-01-28 00:38:35 +00:00
Richard Smith
600b5261c4 PR0091R3: Implement parsing support for using templates as types.
This change adds a new type node, DeducedTemplateSpecializationType, to
represent a type template name that has been used as a type. This is modeled
around AutoType, and shares a common base class for representing a deduced
placeholder type.

We allow deduced class template types in a few more places than the standard
does: in conditions and for-range-declarators, and in new-type-ids. This is
consistent with GCC and with discussion on the core reflector. This patch
does not yet support deduced class template types being named in typename
specifiers.

llvm-svn: 293207
2017-01-26 20:40:47 +00:00
Richard Smith
fd3dae024f Finish implementation of C++ DR1310 (http://wg21.link/cwg1310).
Diagnose the case when a dependent template name instantiates to an
injected-class-name outside a nested-name-specifier.

llvm-svn: 292545
2017-01-20 00:20:39 +00:00
Richard Smith
74f02347ca PR13403 (+duplicates): implement C++ DR1310 (http://wg21.link/cwg1310).
Under this defect resolution, the injected-class-name of a class or class
template cannot be used except in very limited circumstances (when declaring a
constructor, in a nested-name-specifier, in a base-specifier, or in an
elaborated-type-specifier). This is apparently done to make parsing easier, but
it's a pain for us since we don't know whether a template-id using the
injected-class-name is valid at the point when we annotate it (we don't yet
know whether the template-id will become part of an elaborated-type-specifier).

As a tentative resolution to a perceived language defect, mem-initializer-ids
are added to the list of exceptions here (they generally follow the same rules
as base-specifiers).

When the reference to the injected-class-name uses the 'typename' or 'template'
keywords, we permit it to be used to name a type or template as an extension;
other compilers also accept some cases in this area. There are also a couple of
corner cases with dependent template names that we do not yet diagnose, but
which will also get this treatment.

llvm-svn: 292518
2017-01-19 21:00:13 +00:00
Richard Smith
11255ec765 PR9551: Implement DR1004 (http://wg21.link/cwg1004).
This rule permits the injected-class-name of a class template to be used as
both a template type argument and a template template argument, with no extra
syntax required to disambiguate.

llvm-svn: 292426
2017-01-18 19:19:22 +00:00
Richard Smith
957fbf1f9f Partial revert of r290511.
The rules around typechecking deduced template arguments during partial
ordering are not clear, and while the prior behavior does not seem to be
correct (it doesn't follow the general model of partial ordering where each
template parameter is replaced by a non-dependent but unique value), the new
behavior is also not clearly right and breaks some existing idioms.

The new behavior is retained for dealing with non-type template parameters
with 'auto' types, as without it even the most basic uses of that feature
don't work. We can revisit this once CWG has come to an agreement on how
partial ordering with 'auto' non-type template parameters is supposed to
work.

llvm-svn: 292183
2017-01-17 02:14:37 +00:00
Richard Smith
0c062b408b Give more accurate descriptions of what kind of template we found in diagnostics.
We were previouly assuming that every type template was a class template, which
is not true any more.

llvm-svn: 291988
2017-01-14 02:19:59 +00:00
Shoaib Meenai
5adfb5a814 [Sema] Restrict explicit instantation definition dllexport
In the case where the template class itself is already `dllexport`, the
implicit instantiation will have already emitted all members. When we
check the explicit instantiation definition, the `Specialization` will
have inherited the `dllexport` attribute, so we'll attempt to emit all
members for a second time, which causes an assertion failure. Restrict
the exporting to when the `dllexport` attribute is newly introduced by
the explicit instantiation definition.

Fixes PR31608.

Differential Revision: https://reviews.llvm.org/D28590

llvm-svn: 291877
2017-01-13 01:28:34 +00:00
Vassil Vassilev
352e4412e1 PR31469: Don't add friend template class decls to redecl chain in dependent contexts.
Fixes a crash in modules where the template class decl becomes the most recent
decl in the redeclaration chain and forcing the template instantiator try to
instantiate the friend declaration, rather than the template definition.
    
In practice, A::list<int> produces a TemplateSpecializationType
A::__1::list<int, allocator<type-parameter-0-0> >' failing to replace to
subsitute the default argument to allocator<int>.
    
Kudos Richard Smith (D28399).

llvm-svn: 291753
2017-01-12 09:16:26 +00:00
Vassil Vassilev
2999d0e8bb Remove fixme, use ASTContext::getCanonicalTemplateSpecializationType.
Reviewed by Richard Smith (D28306).

llvm-svn: 291552
2017-01-10 09:09:09 +00:00
Richard Smith
43a833bec4 Check that template template arguments match template template parameters
properly even when a non-type template parameter has a dependent type.

Previously, if a non-type template parameter was dependent, but not dependent
on an outer level of template parameter, we would not match the type of the
parameter. Under [temp.arg.template], we are supposed to check that the types
are equivalent, which means checking for syntactic equivalence in the dependent
case.

This also fixes some accepts-invalids when passing templates with auto-typed
non-type template parameters as template template arguments.

llvm-svn: 291512
2017-01-09 23:54:33 +00:00
Richard Smith
e5945871cf Revisit PR10177: don't instantiate a variable if it's only referenced in a
dependent context and can't be used in a constant expression.

Per C++ [temp.inst]p2, "the instantiation of a static data member does not
occur unless the static data member is used in a way that requires the
definition to exist".

This doesn't /quite/ match that, as we still instantiate static data members
that are usable in constant expressions even if the use doesn't require a
definition. A followup patch will fix that for both variables and functions.

llvm-svn: 291295
2017-01-06 22:52:53 +00:00
Daniel Jasper
5cad6856a3 Remove isIgnored()-test that is more expensive than the analysis behind it
In many translation units I have tried, the calls to isIgnored() removed
in this patch are more expensive than doing the analysis that is behind
it. The speed-up in translation units I have tried is between 10 and
20%.

Review: https://reviews.llvm.org/D28208
llvm-svn: 290842
2017-01-02 22:55:45 +00:00
Richard Smith
26b86ea8b1 [c++17] Implement P0522R0 as written. This allows a template template argument
to be specified for a template template parameter whenever the parameter is at
least as specialized as the argument (when there's an obvious and correct
mapping from uses of the parameter to uses of the argument). For example, a
template with more parameters can be passed to a template template parameter
with fewer, if those trailing parameters have default arguments.

This is disabled by default, despite being a DR resolution, as it's fairly
broken in its current state: there are no partial ordering rules to cope with
template template parameters that have different parameter lists, meaning that
code that attempts to decompose template-ids based on arity can hit unavoidable
ambiguity issues.

The diagnostics produced on a non-matching argument are also pretty bad right
now, but I aim to improve them in a subsequent commit.

llvm-svn: 290792
2016-12-31 21:41:23 +00:00
Simon Pilgrim
6905d22dc2 Wdocumentation fix
llvm-svn: 290773
2016-12-30 22:55:33 +00:00
Richard Smith
15361a21e0 Mark 'auto' as dependent when instantiating the type of a non-type template
parameter. Fixes failed deduction for 'auto' non-type template parameters
nested within templates.

llvm-svn: 290660
2016-12-28 06:27:18 +00:00
Richard Smith
57aae07b4a DR1315: a non-type template argument in a partial specialization is permitted
to make reference to template parameters. This is only a partial
implementation; we retain the restriction that the argument must not be
type-dependent, since it's unclear how that would work given the existence of
other language rules requiring an exact type match in this context, even for
type-dependent cases (a question has been raised on the core reflector).

llvm-svn: 290647
2016-12-28 02:37:25 +00:00
Richard Smith
fa4a09d8af Add warning flag for "partial specialization is not more specialized than primary template" error (since Eigen hits it), and while I'm here also add a warning flag for "partial specialization is not usable because one or more of its parameters cannot be deduced" warning.
llvm-svn: 290625
2016-12-27 20:03:09 +00:00
Richard Smith
0e617ecdd1 DR1495: A partial specialization is ill-formed if it is not (strictly) more
specialized than the primary template. (Put another way, if we imagine there
were a partial specialization matching the primary template, we should never
select it if some other partial specialization also matches.)

llvm-svn: 290593
2016-12-27 07:56:27 +00:00
Richard Smith
d92eddf02d Work around a standard defect: template argument deduction for non-type
template parameters of reference type basically doesn't work, because we're
always deducing from an argument expression of non-reference type, so the type
of the deduced expression never matches. Instead, compare the type of an
expression naming the parameter to the type of the argument.

llvm-svn: 290586
2016-12-27 06:14:37 +00:00
Richard Smith
01bfa68fec Check and build conversion sequences for non-type template arguments in
dependent contexts when processing the template in C++11 and C++14, just like
we do in C++98 and C++1z. This allows us to diagnose invalid templates earlier.

llvm-svn: 290567
2016-12-27 02:02:09 +00:00
Richard Smith
4f9b3f4a5b Update comment to match dr1770.
llvm-svn: 290552
2016-12-26 22:28:29 +00:00
Richard Smith
87d263e870 Fix some subtle wrong partial ordering bugs particularly with C++1z auto-typed
non-type template parameters.

During partial ordering, when checking the substituted deduced template
arguments match the original, check the types of non-type template arguments
match even if they're dependent. The only way we get dependent types here is if
they really represent types of the other template (which are supposed to be
modeled as being substituted for unique, non-dependent types).

In order to make this work for auto-typed non-type template arguments, we need
to be able to perform auto deduction even when the initializer and
(potentially) the auto type are dependent, support for which is the bulk of
this patch. (Note that this requires the ability to deduce only a single level
of a multi-level dependent type.)

llvm-svn: 290511
2016-12-25 08:05:23 +00:00
Richard Smith
792c22dbd4 When producing a name of a partial specialization in a diagnostic, use the
template arguments as written rather than the canonical template arguments,
so we print more user-friendly names for template parameters.

llvm-svn: 290483
2016-12-24 04:09:05 +00:00
Richard Smith
52e624f3ec Perform type-checking for a converted constant expression in a template
argument even if the expression is value-dependent (we need to suppress the
final portion of the narrowing check, but the rest of the checking can still be
done eagerly).

This affects template template argument validity and partial ordering under
p0522r0.

llvm-svn: 290276
2016-12-21 21:42:57 +00:00
Akira Hatanaka
d644e021b5 [Sema] Fix handling of enumerators used as default arguments of lambda
expressions in a function or class template.

This patch makes the following changes:

- Create a DependentScopeDeclRefExpr for the default argument instead of
  a CXXDependentScopeMemberExpr.
- Pass CombineWithOuterScope=true so that the outer scope in which the
  enum is declared is searched for the instantiation of the enum. 

This is the first part of https://reviews.llvm.org/D23096. Fixes PR28795

rdar://problem/27535319

llvm-svn: 289914
2016-12-16 03:19:41 +00:00
Reid Kleckner
1a4ab7e772 Improve error message when referencing a non-tag type with a tag
Other compilers accept invalid code here that we reject, and we need a
better error message to try to convince users that the code is really
incorrect. Consider:
  class Foo {
    typedef MyIterHelper<Foo> iterator;
    friend class iterator;
  };

Previously our wording was "elaborated type refers to a typedef".
"elaborated type" isn't widely known terminology, so the new diagnostic
says "typedef 'iterator' cannot be referenced with class specifier".

Reviewers: rsmith

Differential Revision: https://reviews.llvm.org/D25216

llvm-svn: 289259
2016-12-09 19:47:58 +00:00
Artem Belevich
64135c35f7 [CUDA] Ignore implicit target attributes during function template instantiation.
Some functions and templates are treated as __host__ __device__ even
when they don't have explicitly specified target attributes.
What's worse, this treatment may change depending on command line
options (-fno-cuda-host-device-constexpr) or
#pragma clang force_cuda_host_device.

Combined with strict checking for matching function target that comes
with D25809(r288962), it makes it hard to write code which would
explicitly instantiate or specialize some functions regardless of
pragmas or command line options in effect.

This patch changes the way we match target attributes of base template
vs attributes used in explicit instantiation or specialization so that
only explicitly specified attributes are considered. This makes base
template selection behave consistently regardless of pragma of command
line options that may affect CUDA target.

Differential Revision: https://reviews.llvm.org/D25845

llvm-svn: 289091
2016-12-08 19:38:13 +00:00
Artem Belevich
13e9b4d768 [CUDA] Improve target attribute checking for function templates.
* __host__ __device__ functions are no longer considered to be
  redeclarations of __host__ or __device__ functions. This prevents
  unintentional merging of target attributes across them.
* Function target attributes are not considered (and must match) during
  explicit instantiation and specialization of function templates.

Differential Revision: https://reviews.llvm.org/D25809

llvm-svn: 288962
2016-12-07 19:27:16 +00:00
Shoaib Meenai
fc78d7cb8e [Sema] Respect DLL attributes more faithfully
On MSVC, if an implicit instantiation already exists and an explicit
instantiation definition with a DLL attribute is created, the DLL
attribute still takes effect. Make clang match this behavior for
exporting.

Differential Revision: https://reviews.llvm.org/D26657

llvm-svn: 288682
2016-12-05 18:01:35 +00:00
Saleem Abdulrasool
25dbdfa0ac Sema: delay the DLL exported member referencing
An explicit template specialization can cause the implicit template
specialization of a type which inherits the attributes.  In such a case, we
would end up with a delayed template specialization for a dll exported type
which we would fail to reference.  This would trigger an assertion.

We now propagate the dll storage attributes through the inheritance
chain.  Only after having done so do we reference the delayed template
specializations.  This allows any implicit specializations which inherit dll
storage to also be referenced.

llvm-svn: 288570
2016-12-03 01:57:47 +00:00
Richard Smith
baa4783d31 PR31081: ignore exception specifications when deducing function template
arguments from a declaration; despite what the standard says, this form of
deduction should not be considering exception specifications.

llvm-svn: 288301
2016-12-01 02:11:49 +00:00
Yaron Keren
1cb8146057 Rangify for loop, NFC.
llvm-svn: 287102
2016-11-16 13:45:34 +00:00
Shoaib Meenai
ab3f96cb21 [Sema] Use MS ABI behavior for dllexport in Itanium
Similar to r284288, make the Itanium ABI follow MS ABI dllexport
semantics in the case of an explicit instantiation declaration followed
by a dllexport explicit instantiation definition.

Differential Revision: https://reviews.llvm.org/D26471

llvm-svn: 286419
2016-11-09 23:52:20 +00:00
Alex Lorenz
560ae565e9 Add a note that points to the linkage specifier for the C++ linkage errors
This commit improves the "must have C++ linkage" error diagnostics that are
emitted for C++ declarations like templates and literal operators by adding an
additional note that points to the appropriate extern "C" linkage specifier.

rdar://19021120

Differential Revision: https://reviews.llvm.org/D26189

llvm-svn: 285823
2016-11-02 15:46:34 +00:00