Commit Graph

835 Commits

Author SHA1 Message Date
Louis Dionne 3c011e1e3c [clang] Make sure attributes on member classes are applied properly
Summary:
Attributes on member classes of class templates and member class templates
of class templates are not currently instantiated. This was discovered by
Richard Smith here:

  http://lists.llvm.org/pipermail/cfe-dev/2018-September/059291.html

This commit makes sure that attributes are instantiated properly. This
commit does not fix the broken behavior for member partial and explicit
specializations of class templates.

PR38913

Reviewers: rsmith

Subscribers: dexonsmith, cfe-commits

Differential Revision: https://reviews.llvm.org/D51997

llvm-svn: 342238
2018-09-14 14:07:16 +00:00
Alexey Bataev e6aa4694de [OPENMP] Fix PR38903: Crash on instantiation of the non-dependent
declare reduction.

If the declare reduction construct with the non-dependent type is
defined in the template construct, the compiler might crash on the
template instantition. Reworked the whole instantiation scheme for the
declare reduction constructs to fix this problem correctly.

llvm-svn: 342151
2018-09-13 16:54:05 +00:00
Richard Smith c457766c6d Consistently create a new declaration when merging a pre-existing but
hidden definition with a would-be-parsed redefinition.

This permits a bunch of cleanups. In particular, we no longer need to
take merged definitions into account when checking declaration
visibility, only when checking definition visibility, which makes
certain visibility checks take linear instead of quadratic time.

We could also now remove the UPD_DECL_EXPORTED update record and track
on each declaration whether it was demoted from a definition (as we
already do for variables), but I'm not doing that in this patch to keep
the changes here simpler.

llvm-svn: 342018
2018-09-12 02:13:47 +00:00
Richard Smith 5159bbad8b PR38627: Fix handling of exception specification adjustment for
destructors.

We previously tried to patch up the exception specification after
completing the class, which went wrong when the exception specification
was needed within the class body (in particular, by a friend
redeclaration of the destructor in a nested class). We now mark the
destructor as having a not-yet-computed exception specification
immediately after creating it.

This requires delaying various checks against the exception
specification (where we'd previously have just got the wrong exception
specification, and now find we have an exception specification that we
can't compute yet) when those checks fire while the class is being
defined.

This also exposed an issue that we were missing a CodeSynthesisContext
for computation of exception specifications (otherwise we'd fail to make
the module containing the definition of the class visible when computing
its members' exception specs). Adding that incidentally also gives us a
diagnostic quality improvement.

This has also exposed an pre-existing problem: making the exception
specification evaluation context a non-SFINAE context (as it should be)
results in a bootstrap failure; PR38850 filed for this.

llvm-svn: 341499
2018-09-05 22:30:37 +00:00
Erich Keane 0fb16483ac Enforce instantiation of template multiversion functions
Multiversioned member functions inside of a template type were 
not properly being emitted.  The solution to this is to simply 
ensure that their bodies are correctly evaluated/assigned during
template instantiation.

llvm-svn: 339597
2018-08-13 18:33:20 +00:00
Stephen Kelly 1c301dcbc4 Port getLocEnd -> getEndLoc
Reviewers: teemperor!

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D50351

llvm-svn: 339386
2018-08-09 21:09:38 +00:00
Stephen Kelly f2ceec4811 Port getLocStart -> getBeginLoc
Reviewers: teemperor!

Subscribers: jholewinski, whisperity, jfb, cfe-commits

Differential Revision: https://reviews.llvm.org/D50350

llvm-svn: 339385
2018-08-09 21:08:08 +00:00
Fangrui Song 6907ce2f8f Remove trailing space
sed -Ei 's/[[:space:]]+$//' include/**/*.{def,h,td} lib/**/*.{cpp,h}

llvm-svn: 338291
2018-07-30 19:24:48 +00:00
Erich Keane c480f30580 AttributeList de-listifying:
Basically, "AttributeList" loses all list-like mechanisms, ParsedAttributes is
switched to use a TinyPtrVector (and a ParsedAttributesView is created to
have a non-allocating attributes list). DeclaratorChunk gets the later kind,
Declarator/DeclSpec keep ParsedAttributes.

Iterators are added to the ParsedAttribute types so that for-loops work.

llvm-svn: 336945
2018-07-12 21:09:05 +00:00
Taiju Tsuiki 3be68e162f Revert r335019 "Update NRVO logic to support early return (Attempt 2)"
llvm-svn: 335022
2018-06-19 05:35:30 +00:00
Taiju Tsuiki b000a8860e Update NRVO logic to support early return (Attempt 2)
Summary:
This is the second attempt of r333500 (Update NRVO logic to support early return).
The previous one was reverted for a miscompilation for an incorrect NRVO set up on templates such as:
```
struct Foo {};

template <typename T>
T bar() {
  T t;
  if (false)
    return T();
  return t;
}
```

Where, `t` is marked as non-NRVO variable before its instantiation. However, while its instantiation, it's left an NRVO candidate, turned into an NRVO variable later.

Reviewers: rsmith

Reviewed By: rsmith

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D47586

llvm-svn: 335019
2018-06-19 04:39:07 +00:00
Artem Belevich e9fa53a09b [CUDA] Check initializers of instantiated template variables.
We were already performing checks on non-template variables,
but the checks on templated ones were missing.

Differential Revision: https://reviews.llvm.org/D45231

llvm-svn: 334143
2018-06-06 22:37:25 +00:00
Richard Smith 2600c63d96 PR34520: after instantiating a non-templated member deduction guide, don't forget to push it into the class scope.
llvm-svn: 333589
2018-05-30 20:24:10 +00:00
Adrian Prantl 9fc8faf9e6 Remove \brief commands from doxygen comments.
This is similar to the LLVM change https://reviews.llvm.org/D46290.

We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.

Patch produced by

for i in $(git grep -l '\@brief'); do perl -pi -e 's/\@brief //g' $i & done
for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done

Differential Revision: https://reviews.llvm.org/D46320

llvm-svn: 331834
2018-05-09 01:00:01 +00:00
Faisal Vali a534f07f8c Revert rC330794 and some dependent tiny bug fixes
See Richard's humbling feedback here: 
http://lists.llvm.org/pipermail/cfe-commits/Week-of-Mon-20180423/226482.html
http://lists.llvm.org/pipermail/cfe-commits/Week-of-Mon-20180423/226486.html

Wish I'd had the patience to solicit the feedback prior to committing :)

Sorry for the noise guys.

Thank you Richard for being the steward that clang deserves!

llvm-svn: 330888
2018-04-26 00:42:40 +00:00
Faisal Vali 936de9d666 [c++2a] [concepts] Add rudimentary parsing support for template concept declarations
This patch is a tweak of changyu's patch: https://reviews.llvm.org/D40381. It differs in that the recognition of the 'concept' token is moved into the machinery that recognizes declaration-specifiers - this allows us to leverage the attribute handling machinery more seamlessly.

See the test file to get a sense of the basic parsing that this patch supports. 

There is much more work to be done before concepts are usable...

Thanks Changyu!

llvm-svn: 330794
2018-04-25 02:42:26 +00:00
Artem Belevich 67d22c8a84 Revert "[CUDA] Check initializers of instantiated template variables."
This (temporarily) reverts commit r329127 due to the problems
it exposed in TensorFlow.

llvm-svn: 329229
2018-04-04 20:48:42 +00:00
Artem Belevich d9189d1e76 [CUDA] Check initializers of instantiated template variables.
We were already performing checks on non-template variables,
but the checks on templated ones were missing.

Differential Revision: https://reviews.llvm.org/D45231

llvm-svn: 329127
2018-04-03 22:41:06 +00:00
George Karpenkov ec38cf7aed [ast] Do not auto-initialize Objective-C for-loop variables in Objective-C++ in templatized code under ARC
The AST for the fragment

```
@interface I
@end

template <typename>
void decode(I *p) {
  for (I *k in p) {}
}

void decode(I *p) {
  decode<int>(p);
}
```

differs heavily when templatized and non-templatized:

```
|-FunctionTemplateDecl 0x7fbfe0863940 <line:4:1, line:7:1> line:5:6 decode
| |-TemplateTypeParmDecl 0x7fbfe0863690 <line:4:11> col:11 typename depth 0 index 0
| |-FunctionDecl 0x7fbfe08638a0 <line:5:1, line:7:1> line:5:6 decode 'void (I *__strong)'
| | |-ParmVarDecl 0x7fbfe08637a0 <col:13, col:16> col:16 referenced p 'I *__strong'
| | `-CompoundStmt 0x7fbfe0863b88 <col:19, line:7:1>
| |   `-ObjCForCollectionStmt 0x7fbfe0863b50 <line:6:3, col:20>
| |     |-DeclStmt 0x7fbfe0863a50 <col:8, col:13>
| |     | `-VarDecl 0x7fbfe08639f0 <col:8, col:11> col:11 k 'I *const __strong'
| |     |-ImplicitCastExpr 0x7fbfe0863a90 <col:16> 'I *' <LValueToRValue>
| |     | `-DeclRefExpr 0x7fbfe0863a68 <col:16> 'I *__strong' lvalue ParmVar 0x7fbfe08637a0 'p' 'I *__strong'
| |     `-CompoundStmt 0x7fbfe0863b78 <col:19, col:20>
| `-FunctionDecl 0x7fbfe0863f80 <line:5:1, line:7:1> line:5:6 used decode 'void (I *__strong)'
|   |-TemplateArgument type 'int'
|   |-ParmVarDecl 0x7fbfe0863ef8 <col:13, col:16> col:16 used p 'I *__strong'
|   `-CompoundStmt 0x7fbfe0890cf0 <col:19, line:7:1>
|     `-ObjCForCollectionStmt 0x7fbfe0890cc8 <line:6:3, col:20>
|       |-DeclStmt 0x7fbfe0890c70 <col:8, col:13>
|       | `-VarDecl 0x7fbfe0890c00 <col:8, col:11> col:11 k 'I *__strong' callinit
|       |   `-ImplicitValueInitExpr 0x7fbfe0890c60 <<invalid sloc>> 'I *__strong'
|       |-ImplicitCastExpr 0x7fbfe0890cb0 <col:16> 'I *' <LValueToRValue>
|       | `-DeclRefExpr 0x7fbfe0890c88 <col:16> 'I *__strong' lvalue ParmVar 0x7fbfe0863ef8 'p' 'I *__strong'
|       `-CompoundStmt 0x7fbfe0863b78 <col:19, col:20>
```

Note how in the instantiated version ImplicitValueInitExpr unexpectedly appears.

While objects are auto-initialized under ARC, it does not make sense to
have an initializer for a for-loop variable, and it makes even less
sense to have such a different AST for instantiated and non-instantiated
version.

Digging deeper, I have found that there are two separate Sema* files for
dealing with templates and for dealing with non-templatized code.
In a non-templatized version, an initialization was performed only for
variables which are not loop variables for an Objective-C loop and not
variables for a C++ for-in loop:

```
  if (FRI && (Tok.is(tok::colon) || isTokIdentifier_in())) {
    bool IsForRangeLoop = false;
    if (TryConsumeToken(tok::colon, FRI->ColonLoc)) {
      IsForRangeLoop = true;
      if (Tok.is(tok::l_brace))
        FRI->RangeExpr = ParseBraceInitializer();
      else
        FRI->RangeExpr = ParseExpression();
    }

    Decl *ThisDecl = Actions.ActOnDeclarator(getCurScope(), D);
    if (IsForRangeLoop)
      Actions.ActOnCXXForRangeDecl(ThisDecl);
    Actions.FinalizeDeclaration(ThisDecl);
    D.complete(ThisDecl);
    return Actions.FinalizeDeclaratorGroup(getCurScope(), DS, ThisDecl);
  }

  SmallVector<Decl *, 8> DeclsInGroup;
  Decl *FirstDecl = ParseDeclarationAfterDeclaratorAndAttributes(
      D, ParsedTemplateInfo(), FRI);
```

However the code in SemaTemplateInstantiateDecl was inconsistent,
guarding only against C++ for-in loops.

rdar://38391075

Differential Revision: https://reviews.llvm.org/D44989

llvm-svn: 328749
2018-03-29 00:56:24 +00:00
Reid Kleckner 24bd88c0b0 [MS] Fix late-parsed template infinite loop in eager instantiation
Summary:
This fixes PR33561 and PR34185.

Don't store pending template instantiations for late-parsed templates in
the normal PendingInstantiations queue. Instead, use a separate list
that will only be parsed and instantiated at end of TU when late
template parsing actually works and doesn't infinite loop.

Reviewers: rsmith, thakis, hans

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D44846

llvm-svn: 328567
2018-03-26 18:22:47 +00:00
Jordan Rose 1e879d8be6 Sink PrettyDeclStackTrace down to the AST library
...and add some very basic stack trace entries for module building.
This would have helped track down rdar://problem/38434694 sooner.

llvm-svn: 328276
2018-03-23 00:07:18 +00:00
George Burgess IV 18b28a86c1 Properly construct `inline` members without initializers
Digging through commit logs, it appears the checks in this block predate
`inline` class variables. With them, we fail to emit dynamic
initializers for members that don't have an explicit initializer, and we
won't go out of our way to instantiate the class denoted by
`Var->getType()`.

Fixes PR35599.

llvm-svn: 327945
2018-03-20 03:27:44 +00:00
Richard Smith c660c8f5d2 Implement C++ DR727, which permits explicit specializations at class scope.
More generally, this permits a template to be specialized in any scope in which
it could be defined, so this also supersedes DR44 and DR374 (the latter of
which we previously only implemented in C++11 mode onwards due to unclarity as
to whether it was a DR).

llvm-svn: 327705
2018-03-16 13:36:56 +00:00
Richard Trieu 09c163bb6b Refactoring code around move/copy initialization. NFC.
Use an enum parameter instead of a bool for more control on how the copy elision
functions work.  Extract the move initialization code from the move or copy
initialization block.

Patch by: Arthur O'Dwyer

Differential Revision: https://reviews.llvm.org/D43898

llvm-svn: 327598
2018-03-15 03:00:55 +00:00
Ilya Biryukov 0ee4a08c00 [Sema] Pop function scope when instantiating a func with skipped body
Summary:
By calling ActOnFinishFunctionBody(). Previously we were only calling
ActOnSkippedFunctionBody, which didn't pop the function scope.
This causes a crash when running on our internal code. No test-case,
though, since I couldn't come up with a small example in reasonable
time.

The bug was introduced in r321174.

Reviewers: bkramer, sammccall, sepavloff, aaron.ballman

Reviewed By: sammccall, aaron.ballman

Subscribers: aaron.ballman, cfe-commits

Differential Revision: https://reviews.llvm.org/D44439

llvm-svn: 327504
2018-03-14 13:18:30 +00:00
Joel E. Denny 8150810556 Reland "[Attr] Fix parameter indexing for several attributes"
Relands r326602 (reverted in r326862) with new test and fix for
PR36620.

Differential Revision: https://reviews.llvm.org/D43248

llvm-svn: 327405
2018-03-13 14:51:22 +00:00
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
Nico Weber bbf648253d Revert r326602, it caused PR36620.
llvm-svn: 326862
2018-03-07 02:22:41 +00:00
Joel E. Denny 4925445958 [Attr] Fix parameter indexing for several attributes
The patch fixes a number of bugs related to parameter indexing in
attributes:

* Parameter indices in some attributes (argument_with_type_tag,
  pointer_with_type_tag, nonnull, ownership_takes, ownership_holds,
  and ownership_returns) are specified in source as one-origin
  including any C++ implicit this parameter, were stored as
  zero-origin excluding any this parameter, and were erroneously
  printing (-ast-print) and confusingly dumping (-ast-dump) as the
  stored values.

* For alloc_size, the C++ implicit this parameter was not subtracted
  correctly in Sema, leading to assert failures or to silent failures
  of __builtin_object_size to compute a value.

* For argument_with_type_tag, pointer_with_type_tag, and
  ownership_returns, the C++ implicit this parameter was not added
  back to parameter indices in some diagnostics.

This patch fixes the above bugs and aims to prevent similar bugs in
the future by introducing careful mechanisms for handling parameter
indices in attributes.  ParamIdx stores a parameter index and is
designed to hide the stored encoding while providing accessors that
require each use (such as printing) to make explicit the encoding that
is needed.  Attribute declarations declare parameter index arguments
as [Variadic]ParamIdxArgument, which are exposed as ParamIdx[*].  This
patch rewrites all attribute arguments that are processed by
checkFunctionOrMethodParameterIndex in SemaDeclAttr.cpp to be declared
as [Variadic]ParamIdxArgument.  The only exception is xray_log_args's
argument, which is encoded as a count not an index.

Differential Revision: https://reviews.llvm.org/D43248

llvm-svn: 326602
2018-03-02 19:03:22 +00:00
Serge Pavlov e6e534ca22 Function definition may have uninstantiated body
Current implementation of `FunctionDecl::isDefined` does not take into
account redeclarations that do not have bodies, but the bodies can be
instantiated from corresponding templated definition. This behavior does
not allow to detect function redefinition in the cases where friend
functions is defined in class templates. For instance, the code:
```
    template<typename T> struct X { friend void f() {} };
    X<int> xi;
    void f() {}
```
compiles successfully but must fail due to redefinition of `f`. The
declaration of the friend `f` is created when the containing template
`X` is instantiated, but it does not have a body as per 14.5.4p4
because `f` is not odr-used.

With this change the function `Sema::CheckForFunctionRedefinition`
considers functions with uninstantiated bodies as definitions.

Differential Revision: https://reviews.llvm.org/D30170

llvm-svn: 326419
2018-03-01 07:04:11 +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
Reid Kleckner b0a17edff7 [Sema] Don't mark plain MS enums as fixed
Summary:
This fixes a flaw in our AST: PR27098

MSVC always gives plain enums the underlying type 'int'. Clang does this
as well, but we claim the enum is "fixed", as if the user actually wrote
': int'. It means we end up emitting spurious -Wsign-compare warnings on
code like this:

  enum Vals { E1, E2, E3 };
  bool f(unsigned v1, Vals v2) {
    return v1 == v2;
  }

We think 'v2' can take on negative values because we think 'Vals' is
fixed. This fixes that.

Reviewers: rsmith

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D43110

llvm-svn: 324913
2018-02-12 17:37:06 +00:00
Gabor Horvath 207e7b1fa1 [Templight] Template Instantiation Observer
This patch adds a base-class called TemplateInstantiationObserver which gets
notified whenever a template instantiation is entered or exited during
semantic analysis. This is a base class used to implement the template
profiling and debugging tool called
Templight (https://github.com/mikael-s-persson/templight).

The patch also makes a few more changes:

* ActiveTemplateInstantiation class is moved out of the Sema class (so it can be used with inclusion of Sema.h).
* CreateFrontendAction function in front-end utilities is given external linkage (not longer a hidden static function).
* TemplateInstObserverChain data member added to Sema class to hold the list of template-inst observers.
* Notifications to the template-inst observer are added at the key places where templates are instantiated.

Patch by: Abel Sinkovics!

Differential Revision: https://reviews.llvm.org/D5767

llvm-svn: 324808
2018-02-10 14:04:45 +00:00
Richard Smith 93ee9caaed In C++17, when instantiating an out-of-line definition of an inline static data
member, don't forget to instantiate the initializer too.

llvm-svn: 322236
2018-01-10 23:08:26 +00:00
Richard Smith 33bddbd64b Make attribute instantiation instantiate all attributes, not just the first of
each kind.

Attribute instantiation would previously default to instantiating each kind of
attribute only once. This was overridden by a flag whose intended purpose was
to permit attributes from a prior declaration to be inherited onto a new
declaration even if that new declaration had its own copy of the attribute.
This is the wrong behavior: when instantiating attributes from a template, we
should always instantiate all the attributes that were written on that
template.

This patch renames the flag in the Attr class (and TableGen sources) to more
clearly identify what it's actually for, and removes the usage of the flag from
template instantiation. I also removed the flag from AlignedAttr, which was
only added to work around the incorrect suppression of duplicate attribute
instantiation.

llvm-svn: 321834
2018-01-04 23:42:29 +00:00
Richard Smith 50e291eaf2 Fix and simplify handling of return type for (generic) lambda conversion function to function pointer.
Previously, we would:
 * compute the type of the conversion function and static invoker as a
   side-effect of template argument deduction for a conversion
 * re-compute the type as part of deduced return type deduction when building
   the conversion function itself

Neither of these turns out to be quite correct. There are other ways to reach a
declaration of the conversion function than in a conversion (such as an
explicit call or friend declaration), and performing auto deduction causes the
function type to be rebuilt in the context of the lambda closure type (which is
different from the context in which it originally appeared, resulting in
spurious substitution failures for constructs that are valid in one context but
not the other, such as the use of an enclosing class's "this" pointer).

This patch switches us to use a different strategy: as before, we use the
declared type of the operator() to form the type of the conversion function and
invoker, but we now populate that type as part of return type deduction for the
conversion function. And the invoker is now treated as simply being an
implementation detail of building the conversion function, and isn't given
special treatment by template argument deduction for the conversion function
any more.

llvm-svn: 321683
2018-01-02 23:52:42 +00:00
Nick Lewycky 2adab1bc56 Suppress undefined-template warnings when the pattern is declared in a system header.
The way to fix an undefined-template warning is to add lines to the header file that defines the template pattern. We should suppress the warnings when the template pattern is in a system header because we don't expect users to edit those.

llvm-svn: 321665
2018-01-02 19:10:12 +00:00
Ilya Biryukov 95f0d3286b [Frontend] Correctly handle instantiating ctors with skipped bodies
Summary:
Previsouly clang tried instantiating member initializers even if ctor
body was skipped, this caused spurious errors (see the test).

Reviewers: sepavloff, klimek

Reviewed By: sepavloff

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D41492

llvm-svn: 321520
2017-12-28 13:05:46 +00:00
Richard Smith 4fa14515ac When instantiating a deduction guide, transform its name.
Otherwise it will serve as a deduction guide for the wrong class template.

llvm-svn: 321297
2017-12-21 19:43:39 +00:00
Ilya Biryukov a27eca283b [Frontend] Handle skipped bodies in template instantiations
Summary:
- Fixed an assert in Sema::InstantiateFunctionDefinition and added
  support for instantiating a function template with skipped body.
- Properly call setHasSkippedBody for FunctionTemplateDecl passed to
  Sema::ActOnSkippedFunctionBody.

Reviewers: sepavloff, bkramer

Reviewed By: sepavloff

Subscribers: klimek, cfe-commits

Differential Revision: https://reviews.llvm.org/D41237

llvm-svn: 321174
2017-12-20 14:32:38 +00:00
Adrian Prantl f3b3ccda59 Silence a bunch of implicit fallthrough warnings
llvm-svn: 321115
2017-12-19 22:06:11 +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
Richard Smith 435e647a41 PR35456: Track definedness of variable template specializations separately from
whether they have an initializer.

We cannot distinguish between a declaration of a variable template
specialization and a definition of one that lacks an initializer without this,
and would previously mistake the latter for the former.

llvm-svn: 319605
2017-12-02 02:48:42 +00:00
Richard Smith cb18957da0 Never try to instantiate a deduction guide's "definition". Fixes bogus warning when there inevitably isn't one.
llvm-svn: 316820
2017-10-28 01:15:00 +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 4309b66710 Don't suppress instantiation of definitions for variables subject to explicit
instantiation declarations if they are usable from constant expressions.

We are permitted to instantiate in these cases, and required to do so in order
to have an initializer available for use within constant evaluation.

llvm-svn: 316136
2017-10-18 22:45:01 +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