Commit Graph

1068 Commits

Author SHA1 Message Date
Richard Smith
5d3310208a When substituting previously-checked template arguments into a template
template parameter that is an expanded parameter pack, only substitute into the
current slice, not the entire pack.

This reduces the checking of N template template arguments for an expanded
parameter pack containing N parameters from quadratic time to linear time in
the length of the pack. This is important because one (and possibly the only?)
general technique for splitting a template parameter pack in linear time
depends on doing this.

llvm-svn: 326973
2018-03-08 01:07:33 +00:00
George Burgess IV
00f70bd933 Remove redundant casts. NFC
So I wrote a clang-tidy check to lint out redundant `isa`, `cast`, and
`dyn_cast`s for fun. This is a portion of what it found for clang; I
plan to do similar cleanups in LLVM and other subprojects when I find
time.

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

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

llvm-svn: 326416
2018-03-01 05:43:23 +00:00
Richard Smith
77a9c60aa6 Fix a couple of cases where we would fail to correctly parse deduced class template specialization types.
Specifically, we would not properly parse these types within template arguments
(for non-type template parameters), and in tentative parses. Fixing both of
these essentially requires that we parse deduced template specialization types
as types in all contexts, even in template argument lists -- in particular,
tentative parsing may look ahead and annotate a deduced template specialization
type before we figure out that we're actually supposed to treat the tokens as a
template-name. We deal with this by simply permitting deduced template
specialization types when parsing template arguments, and converting them to
template template arguments.

llvm-svn: 326299
2018-02-28 03:02:23 +00:00
Faisal Vali
090da2d1ac Again reverting an attempt to convert the DeclSpec enums into scoped enums.
- reverts r321622, r321625, and r321626.
  - the use of bit-fields is still resulting in warnings - even though we can use static-asserts to harden the code and ensure the bit-fields are wide enough.  The bots still complain of warnings being seen.
  - to silence the warnings requires specifying the bit-fields with the underlying enum type (as opposed to the enum type itself), which then requires lots of unnecessary static casts of each enumerator within DeclSpec to the underlying-type, which even though could be seen as implementation details, it does hamper readability - and given the additional litterings, makes me question the value of the change.

So in short - I give up (for now at least).  

Sorry about the noise.

llvm-svn: 321628
2018-01-01 18:23:28 +00:00
Faisal Vali
038df49033 [NFC] Modernize enums TypeSpecifierWidth, TypeSpecifierSign & TypeSpecifierType into scoped enums with underlying types.
- Since these enums are used as bit-fields - for the bit-fields to be interpreted as unsigned, the underlying type must be specified as unsigned.

Previous failed attempt - wherein I did not specify an underlying type - was the sum of:
https://reviews.llvm.org/rC321614
https://reviews.llvm.org/rC321615

llvm-svn: 321622
2018-01-01 15:42:13 +00:00
Faisal Vali
c535adcfc5 Revert r321614 and r321615
- the enum changes to TypeSpecifierType are breaking some tests - and will require a more careful integration.

Sorry about rushing these changes - thought I could sneak them in prior to heading out for new years ;)

llvm-svn: 321616
2018-01-01 02:49:17 +00:00
Faisal Vali
8736dee017 [NFC] Modernize enums TypeSpecifierWidth, TypeSpecifierSign & TypeSpecifierType into scoped enums.
llvm-svn: 321614
2018-01-01 02:19:52 +00:00
Faisal Vali
2ab8c15cf1 [NFC] Modernize enum 'UnqualifiedId::IdKind' into a scoped enum UnqualifiedIdKind.
llvm-svn: 321574
2017-12-30 04:15:27 +00:00
Faisal Vali
be29403633 [NFC] Update the template-parameter parsers and analyzers to return NamedDecl (vs Decl)
This patch addresses a FIXME and has the template-parameter processing functions return a more derived common type NamedDecl (as opposed to a type needlessly higher up in the inheritance hierarchy : Decl).  

llvm-svn: 321409
2017-12-23 18:56:34 +00:00
Sam McCall
1371cba56f Fix unused variable warning in SemaTemplate. NFC
llvm-svn: 321346
2017-12-22 07:09:51 +00:00
Faisal Vali
a223d1c856 Diagnose the various invalid decl-specifiers on nontype template parameters.
The standard correctly forbids various decl-specifiers that dont make sense on non-type template parameters - such as the extern in:
    template<extern int> struct X;

This patch implements those restrictions (in a fashion similar to the corresponding checks on function parameters within ActOnParamDeclarator).

Credit goes to miyuki (Mikhail Maltsev) for drawing attention to this issue,  authoring the initial versions of this patch, and supporting the effort to re-engineer it slightly.  Thank you!

For details of how this patch evolved please see: https://reviews.llvm.org/D40705

llvm-svn: 321339
2017-12-22 03:50:55 +00:00
Hubert Tong
bd72cd9577 Remove old concepts parsing code
Summary:
This is so we can implement concepts per P0734R0. Relevant failing test
cases are disabled.

Reviewers: hubert.reinterpretcast, rsmith, saar.raz, nwilson

Reviewed By: saar.raz

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D40380

Patch by Changyu Li!

llvm-svn: 319992
2017-12-07 00:34:20 +00:00
Richard Smith
891fc7f37a Generalize "static data member instantiated" notification to cover variable templates too.
While here, split the "point of instantiation changed" notification out from
it; these two really are orthogonal changes.

llvm-svn: 319727
2017-12-05 01:31:47 +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
Hans Wennborg
b8304a6aed MS ABI: Treat explicit instantiation definitions of dllimport function templates as explicit instantiation decls (PR35435)
This matches MSVC's behaviour, and we already do it for class templates
since r270897.

Differential revision: https://reviews.llvm.org/D40621

llvm-svn: 319386
2017-11-29 23:44:11 +00:00
Erich Keane
af0795b906 Fix template parameter default args missed if redecled
This bug was found via self-build on lld, and worked around
here: https://reviews.llvm.org/rL316180

The issue is that the 'using' causes the lookup to pick up the
first decl. However, when setting inherited default parameters,
we only update 'forward', not 'backward'. SO, only the newest param
list has all the information about the default arguments.

This patch ensures that the list of parameters we look through checks
the newest decl's template parameter list so it doesn't miss a default.

Differential Revision: https://reviews.llvm.org/D39127

llvm-svn: 316405
2017-10-24 01:39:56 +00:00
Faisal Vali
81b756e6a3 [C++17] Fix PR34970 - tweak overload resolution for class template deduction-guides in line with WG21's p0620r0.
In order to identify the copy deduction candidate, I considered two approaches:
  - attempt to determine whether an implicit guide is a copy deduction candidate by checking certain properties of its subsituted parameter during overload-resolution.
  - using one of the many bits (WillHaveBody) from FunctionDecl (that CXXDeductionGuideDecl inherits from) that are otherwise irrelevant for deduction guides

After some brittle gymnastics w the first strategy, I settled on the second, although to avoid confusion and to give that bit a better name, i turned it into a member of an anonymous union.

Given this identification 'bit', the tweak to overload resolution was a simple reordering of the deduction guide checks (in SemaOverload.cpp::isBetterOverloadCandidate), in-line with Jason Merrill's p0620r0 drafting which made it into the working paper.  Concordant with that, I made sure the copy deduction candidate is always added.


References:
See https://bugs.llvm.org/show_bug.cgi?id=34970 
See http://wg21.link/p0620r0

llvm-svn: 316292
2017-10-22 14:45:08 +00:00
Richard Smith
becb92dec8 [Modules TS] Module ownership semantics for redeclarations.
When declaring an entity in the "purview" of a module, it's never a
redeclaration of an entity in the purview of a default module or in no module
("in the global module"). Don't consider those other declarations as possible
redeclaration targets if they're not visible, and reject any cases where we
pick a prior visible declaration that violates this rule.

This reinstates r315251 and r315256, reverted in r315309 and r315308
respectively, tweaked to avoid triggering a linkage calculation when declaring
implicit special members (this exposed our pre-existing issue with typedef
names for linkage changing the linkage of types whose linkage has already been
computed and cached in more cases). A testcase for that regression has been
added in r315366.

llvm-svn: 315379
2017-10-10 22:33:17 +00:00
Eric Liu
f01516db8d Revert "[Modules TS] Module ownership semantics for redeclarations."
This reverts commit r315251. See the original commit thread for reason.

llvm-svn: 315309
2017-10-10 13:09:40 +00:00
Richard Smith
b87720b77a [Modules TS] Module ownership semantics for redeclarations.
When declaring an entity in the "purview" of a module, it's never a
redeclaration of an entity in the purview of a default module or in no module
("in the global module"). Don't consider those other declarations as possible
redeclaration targets if they're not visible, and reject any cases where we
pick a prior visible declaration that violates this rule.

llvm-svn: 315251
2017-10-09 23:42:09 +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
Douglas Gregor
672281a511 Diagnostic specific failed condition in a static_assert.
When a static_assert fails, dig out a specific condition to diagnose,
using the same logic that we use to find the enable_if condition to
diagnose.

llvm-svn: 313315
2017-09-14 23:38:42 +00:00
Faisal Vali
f241b0dcd6 [NFC] Remove a cstyle cast and replace some uses of Decl with NamedDecl during the processing of TemplateParameterLists.
llvm-svn: 311788
2017-08-25 18:24:20 +00:00
Reid Kleckner
cd016d8dc6 [MS] Don't statically initialize dllimport member function pointers
Summary:
r306137 made dllimport pointers to member functions non-constant. This
is correct because a load must be executed to resolve any dllimported
data. However, r306137 did not account for the use of dllimport member
function pointers used as template arguments.

This change re-lands r306137 with a template instantiation fix.

This fixes PR33570.

Reviewers: rnk, majnemer

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D34714

llvm-svn: 307446
2017-07-07 22:04:29 +00:00
Douglas Gregor
c0fe1f211a Fix test case in pre-C++11 mode; address Aaron Ballman's code review.
llvm-svn: 307202
2017-07-05 21:12:37 +00:00
Douglas Gregor
bb33f57045 Cope with Range-v3's CONCEPT_REQUIRES idiom
llvm-svn: 307197
2017-07-05 20:20:15 +00:00
Douglas Gregor
00fa10b43f Customize the SFINAE diagnostics for enable_if to provide the failed condition.
When enable_if disables a particular overload resolution candidate,
rummage through the enable_if condition to find the specific condition
that caused the failure. For example, if we have something like:

    template<
      typename Iter,
      typename = std::enable_if_t<Random_access_iterator<Iter> &&
                                  Comparable<Iterator_value_type<Iter>>>>
    void mysort(Iter first, Iter last) {}

and we call "mysort" with "std::list<int>" iterators, we'll get a
diagnostic saying that the "Random_access_iterator<Iter>" requirement
failed. If we call "mysort" with
"std::vector<something_not_comparable>", we'll get a diagnostic saying
that the "Comparable<...>" requirement failed.

llvm-svn: 307196
2017-07-05 20:20:14 +00:00
Akira Hatanaka
12ddceecde [Sema] Fix a crash-on-invalid when a template parameter list has a class
definition or non-reference class type.

The crash occurs when there is a template parameter list in a class that
is missing the closing angle bracket followed by a definition of a
struct. For example:

class C0 {
public:
  template<typename T, typename T1 = T // missing closing angle bracket
  struct S0 {};

  C0() : m(new S0<int>) {}
  S0<int> *m;
};

This happens because the parsed struct is added to the scope of the
enclosing class without having its access specifier set, which results
in an assertion failure in SemaAccess.cpp later.

This commit fixes the crash by adding the parsed struct to the enclosing
file scope and marking structs as invalid if they are defined in
template parameter lists.

rdar://problem/31783961
rdar://problem/19570630

Differential Revision: https://reviews.llvm.org/D33606

llvm-svn: 306317
2017-06-26 18:46:12 +00:00
Galina Kistanova
1d36e833e1 Added llvm_unreachable to make sure the switch is always exhaustive.
llvm-svn: 304997
2017-06-08 18:20:32 +00:00
John McCall
27c11dd57e When determining the target function of an explicit instantiation, make
sure that non-template functions don't end up in the candidate set.

Fixes PR14211.

Patch by Don Hinton!

llvm-svn: 304951
2017-06-07 23:00:05 +00:00
Galina Kistanova
3779cb3c14 Added LLVM_FALLTHROUGH to address warning: this statement may fall through. NFC.
llvm-svn: 304870
2017-06-07 06:25:05 +00:00
Richard Smith
54f0440c1f [modules] Switch from inferring owning modules based on source location to
inferring based on the current module at the point of creation.

This should result in no functional change except when building a preprocessed
module (or more generally when using #pragma clang module begin/end to switch
module in the middle of a file), in which case it allows us to correctly track
the owning module for declarations. We can't map from FileID to module in the
preprocessed module case, since all modules would have the same FileID.

There are still a couple of remaining places that try to infer a module from a
source location; I'll clean those up in follow-up changes.

llvm-svn: 303322
2017-05-18 02:29:20 +00:00
Richard Smith
858e0e0a42 Remove unnecessary mapping from SourceLocation to Module.
When we parse a redefinition of an entity for which we have a hidden existing
declaration, make it visible in the current module instead of mapping the
current source location to its containing module.

llvm-svn: 302842
2017-05-11 23:11:16 +00:00
Richard Smith
52f8d19ced Improve diagnosis of unknown template name.
When an undeclared identifier in a context that requires a type is followed by
'<', only look for type templates when typo-correcting, tweak the diagnostic
text to say that a template name (not a type name) was undeclared, and parse
the template arguments when recovering from the error.

llvm-svn: 302732
2017-05-10 21:32:16 +00:00
Richard Smith
42bc73a3f1 When we see a '<' operator, check whether it's a probable typo for a template-id.
The heuristic that we use here is:
 * the left-hand side must be a simple identifier or a class member access
 * the right-hand side must be '<' followed by either a '>' or by a type-id that
   cannot be an expression (in particular, not followed by '(' or '{')
 * there is a '>' token matching the '<' token

The second condition guarantees the expression would otherwise be ill-formed.

If we're confident that the user intended the name before the '<' to be
interpreted as a template, diagnose the fact that we didn't interpret it
that way, rather than diagnosing that the template arguments are not valid
expressions.

llvm-svn: 302615
2017-05-10 02:30:28 +00:00
Richard Smith
77e9e84a8e Don't mark a member as a member specialization until we know we're keeping the specialization.
This improves our behavior in a few ways:

 * We now guarantee that if a member is marked as being a member
   specialization, there will actually be a member specialization declaration
   somewhere on its redeclaration chain. This fixes a crash in modules builds
   where we would try to check that there was a visible declaration of the
   member specialization and be surprised to not find any declaration of it at
   all.

 * We don't set the source location of the in-class declaration of the member
   specialization to the out-of-line declaration's location until we have
   actually finished merging them. This fixes some very silly looking
   diagnostics, where we'd point a "previous declaration is here" note at the
   same declaration we're complaining about. Ideally we wouldn't mess with the
   prior declaration's location at all, but too much code assumes that the
   first declaration of an entity is a reasonable thing to use as an indication
   of where it was declared, and that's not really true for a member
   specialization unless we fake it like this.

llvm-svn: 302596
2017-05-09 23:02:10 +00:00
Richard Smith
479ba8ee0e PR32673: Don't wrap parameter packs in SubstTemplateTypeParmPackType nodes when forming implicit deduction guides.
Doing so thwarts template type deduction. Instead, substitute the pack directly
by picking "slice 0" of the resulting expansion.

llvm-svn: 300805
2017-04-20 01:15:31 +00:00
Richard Smith
1389418e18 PR32185: Revert r291512 and add a testcase for PR32185.
This reverts an attempt to check that types match when matching a
dependently-typed non-type template parameter. (This comes up when matching the
parameters of a template template parameter against the parameters of a
template template argument.)

The matching rules here are murky at best. Our behavior after this revert is
definitely wrong for certain C++17 features (for 'auto' template parameter
types within the parameter list of a template template argument in particular),
but our behavior before this revert is wrong for some pre-existing testcases,
so reverting to our prior behavior seems like our best option.

llvm-svn: 300262
2017-04-13 21:37:24 +00:00
Faisal Vali
d143a0c2de [NFC, Scoped Enum] Convert Sema::ExpressionEvaluationContext into a scoped Enum
- also replace direct equality checks against the ConstantEvaluated enumerator  with isConstantEvaluted(), in anticipation of adding finer granularity to the various ConstantEvaluated contexts and reinstating certain restrictions on where lambda expressions can occur in C++17.

- update the clang tablegen backend that uses these Enumerators, and add the relevant scope where needed.

llvm-svn: 299316
2017-04-01 21:30:49 +00:00
Eric Christopher
0d2c56a5c0 Fix typo, defind -> defined.
llvm-svn: 299148
2017-03-31 01:45:39 +00:00
Erich Keane
a32910da1a Correct class-template deprecation behavior-REDUX
Correct class-template deprecation behavior

Based on the comment in the test, and my reading of the standard, a deprecated warning should be issued in the following case:
template<typename T> [[deprecated]] class Foo{}; Foo<int> f;

This was not the case, because the ClassTemplateSpecializationDecl creation did not also copy the deprecated attribute.

Note: I did NOT audit the complete set of attributes to see WHICH ones should be copied, so instead I simply copy ONLY the deprecated attribute.

Previous DiffRev: https://reviews.llvm.org/D27486, was reverted.
This patch fixes the issues brought up here by the reverter: https://reviews.llvm.org/rL298410

Differential Revision: https://reviews.llvm.org/D31245

llvm-svn: 298634
2017-03-23 18:51:54 +00:00
Martin Bohme
926572303e Revert "Correct class-template deprecation behavior"
This reverts commit r298410 (which produces incorrect warnings, see
comments on https://reviews.llvm.org/rL298410).

llvm-svn: 298504
2017-03-22 13:34:37 +00:00
Erich Keane
8a8f5f0f00 Correct class-template deprecation behavior
Based on the comment in the test, and my reading of the standard, a deprecated warning should be issued in the following case:
template<typename T> [[deprecated]] class Foo{}; Foo<int> f;

This was not the case, because the ClassTemplateSpecializationDecl creation did not also copy the deprecated attribute.

Note: I did NOT audit the complete set of attributes to see WHICH ones should be copied, so instead I simply copy ONLY the deprecated attribute.

Differential Revision: https://reviews.llvm.org/D27486

llvm-svn: 298410
2017-03-21 17:49:17 +00:00
Richard Smith
4ae5ec8268 Improve support for 'decltype(auto)' in template template parameter matching.
A 'decltype(auto)' parameter can match any other kind of non-type template
parameter, so should be usable in place of any other parameter in a template
template argument. The standard is sadly extremely unclear on how this is
supposed to work, but this seems like the obviously-correct result.

It's less clear whether an 'auto' parameter should be able to match
'decltype(auto)', since the former cannot be used if the latter turns out to be
used for a reference type, but if we disallow that then consistency suggests we
should also disallow 'auto' matching 'T' for the same reason, defeating
intended use cases of the feature.

llvm-svn: 295866
2017-02-22 20:01:55 +00:00
Richard Smith
b4f9625a7b PR32010: Fix template argument depth mixup when forming implicit constructor
template deduction guides for class template argument deduction.

Ensure that we have a local instantiation scope for tracking the instantiated
parameters. Additionally, unusually, we're substituting at depth 1 and leaving
depth 0 alone; make sure that we don't reduce template parameter depth by 2 for
inner parameters in the process. (This is probably also broken for alias
templates in the case where they're expanded within a dependent context, but
this patch doesn't fix that.)

llvm-svn: 295696
2017-02-21 06:30:38 +00:00
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
Richard Smith
edbc6e93e1 Reinstate r284008 reverted in r284081, with two fixes:
1) Merge and demote variable definitions when we find a redefinition in
MergeVarDecls, not only when we find one in AddInitializerToDecl (we only reach
the second case if it's the addition of the initializer itself that converts an
existing declaration into a definition). 

2) When rebuilding a redeclaration chain for a variable, if we merge two
definitions together, mark the definitions as merged so the retained definition
is made visible whenever the demoted definition would have been.

Original commit message (from r283882):

[modules] PR28752: Do not instantiate variable declarations which are not visible.

Original patch by Vassil Vassilev! Changes listed above are mine.

llvm-svn: 284284
2016-10-14 21:41:24 +00:00
Richard Smith
88d10b68e0 Revert r284008. This is us to fail to instantiate static data members in some
cases. I'm working on reducing a testcase.

llvm-svn: 284081
2016-10-12 23:29:02 +00:00
Vassil Vassilev
bb8fe3175a Reinstate r283887 and r283882.
Original message:
"[modules] PR28752: Do not instantiate variable declarations which are not visible.

https://reviews.llvm.org/D24508

Patch developed in collaboration with Richard Smith!"

llvm-svn: 284008
2016-10-12 11:57:08 +00:00
Vassil Vassilev
f6b491041f Revert r283887 and r283882, until the issue is understood and fixed.
llvm-svn: 283890
2016-10-11 15:51:06 +00:00