Commit Graph

1170 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 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
George Burgess IV ce6284b179 Change how we handle diagnose_if attributes.
This patch changes how we handle argument-dependent `diagnose_if`
attributes. In particular, we now check them in the same place that we
check for things like passing NULL to Nonnull args, etc. This is
basically better in every way than how we were handling them before. :)

This fixes PR31638, PR31639, and PR31640.

Differential Revision: https://reviews.llvm.org/D28889

llvm-svn: 293360
2017-01-28 02:19:40 +00:00
George Burgess IV d5c7e7c113 Fix a typo. NFC.
llvm-svn: 291997
2017-01-14 05:19:34 +00:00
Richard Smith 836a3b416d PR31606: Generalize our tentative DR resolution for inheriting copy/move
constructors to better match the pre-P0136R1 behavior.

llvm-svn: 291955
2017-01-13 20:46:54 +00:00
Richard Smith 9d05e15c3a Don't try to check implicit conversion sequences for an object argument if
there is no object argument, when early checking of implicit conversion
sequences for a function template fails.

llvm-svn: 291597
2017-01-10 20:52:50 +00:00
Richard Smith 14ead30ab8 Fix conversion index / argument index mismatch when diagnosing overload resolution failure.
llvm-svn: 291596
2017-01-10 20:19:21 +00:00
Richard Smith 6eedfe77c1 Implement C++ DR1391 (wg21.link/cwg1391)
Check for implicit conversion sequences for non-dependent function
template parameters between deduction and substitution. The idea is to accept
as many cases as possible, on the basis that substitution failure outside the
immediate context is much more common during substitution than during implicit
conversion sequence formation.

This re-commits r290808, reverted in r290811 and r291412, with a couple of
fixes for handling of explicitly-specified non-trailing template argument
packs.

llvm-svn: 291427
2017-01-09 08:01:21 +00:00
George Burgess IV 177399e227 Add the diagnose_if attribute to clang.
`diagnose_if` can be used to have clang emit either warnings or errors
for function calls that meet user-specified conditions. For example:

```
constexpr int foo(int a)
  __attribute__((diagnose_if(a > 10, "configurations with a > 10 are "
                                      "expensive.", "warning")));

int f1 = foo(9);
int f2 = foo(10); // warning: configuration with a > 10 are expensive.
int f3 = foo(f2);
```

It currently only emits diagnostics in cases where the condition is
guaranteed to always be true. So, the following code will emit no
warnings:

```
constexpr int bar(int a) {
  foo(a);
  return 0;
}

constexpr int i = bar(10);
```

We hope to support optionally emitting diagnostics for cases like that
(and emitting runtime checks) in the future.

Release notes will appear shortly. :)

Differential Revision: https://reviews.llvm.org/D27424

llvm-svn: 291418
2017-01-09 04:12:14 +00:00
Richard Smith 7950d82ab5 Revert r291410 and r291411.
The test-suite bots are still failing even after r291410's fix.

llvm-svn: 291412
2017-01-09 01:18:18 +00:00
Richard Smith d22652122d Implement C++ DR1391 (wg21.link/cwg1391)
Check for implicit conversion sequences for non-dependent function
template parameters between deduction and substitution. The idea is to accept
as many cases as possible, on the basis that substitution failure outside the
immediate context is much more common during substitution than during implicit
conversion sequence formation.

This re-commits r290808, reverted in r290811, with a fix for handling of
explicitly-specified template argument packs.

llvm-svn: 291410
2017-01-09 00:43:47 +00:00
Richard Smith f9c59b7122 PR30305: Implement proposed DR resolution to prevent slicing via inherited constructor.
The rule we use is that a construction of a class type T from an argument of
type U cannot use an inherited constructor if U is the same as T or is derived
from T (or if the initialization would first convert it to such a type). This
(approximately) matches the rule in use by GCC, and matches the current proposed
DR resolution.

llvm-svn: 291403
2017-01-08 21:45:44 +00:00
Richard Smith c92d206ce4 Add missing "original call argument has same type as deduced parameter type"
check for deductions from elements of a braced-init-list.

llvm-svn: 291190
2017-01-05 23:02:44 +00:00
Richard Smith 363ae815b1 Fix failure to treat overloaded function in braced-init-list as a non-deduced context.
Previously, if an overloaded function in a braced-init-list was encountered in
template argument deduction, and the overload set couldn't be resolved to a
particular function, we'd immediately produce a deduction failure. That's not
correct; this situation is supposed to result in that particular P/A pair being
treated as a non-deduced context, and deduction can still succeed if the type
can be deduced from elsewhere.

llvm-svn: 291014
2017-01-04 22:03:59 +00:00
George Burgess IV 8684b0352a [Sema] Replace remove_if+erase with erase_if. NFC.
llvm-svn: 290991
2017-01-04 19:16:29 +00:00
Renato Golin dad96d6751 Revert "DR1391: Check for implicit conversion sequences for non-dependent function template parameters between deduction and substitution. The idea is to accept as many cases as possible, on the basis that substitution failure outside the immediate context is much more common during substitution than during implicit conversion sequence formation."
This reverts commit r290808, as it broken all ARM and AArch64 test-suite
test: MultiSource/UnitTests/C++11/frame_layout

Also, please, next time, try to write a commit message in according to
our guidelines:

http://llvm.org/docs/DeveloperPolicy.html#commit-messages

llvm-svn: 290811
2017-01-02 11:15:42 +00:00
Richard Smith efcfe86072 DR1391: Check for implicit conversion sequences for non-dependent function
template parameters between deduction and substitution. The idea is to accept
as many cases as possible, on the basis that substitution failure outside
the immediate context is much more common during substitution than during
implicit conversion sequence formation.

This does not implement the partial ordering portion of DR1391, which so
far appears to be misguided.

llvm-svn: 290808
2017-01-02 02:42:17 +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
Egor Churaev 89831421af Fix problems in "[OpenCL] Enabling the usage of CLK_NULL_QUEUE as compare operand."
Summary: Fixed warnings in commit: https://reviews.llvm.org/rL290171

Reviewers: djasper, Anastasia

Subscribers: yaxunl, cfe-commits, bader

Differential Revision: https://reviews.llvm.org/D27981

llvm-svn: 290431
2016-12-23 14:55:49 +00:00
Richard Smith 593d6a168f When merging two deduced non-type template arguments for the same parameter,
fail the merge if the arguments have different types (except if one of them was
deduced from an array bound, in which case take the type from the other).

This is correct because (except in the array bound case) the type of the
template argument in each deduction must match the type of the parameter, so at
least one of the two deduced arguments must have a mismatched type.

This is necessary because we would otherwise lose the type information for the
discarded template argument in the merge, and fail to diagnose the mismatch.

In order to power this, we now properly retain the type of a deduced non-type
template argument deduced from a declaration, rather than giving it the type of
the template parameter; we'll convert it to the template parameter type when
checking the deduced arguments.

llvm-svn: 290399
2016-12-23 01:30:39 +00:00
Saleem Abdulrasool 78704fb6dc Sema: print qualified name for overload candidates
Print the fully qualified names for the overload candidates.  This makes
it easier to tell what the ambiguity is.  Especially if a template
is instantiated after a using namespace, it will not inherit the
namespace where it was declared.  The specialization will give a message
about a partial order being ambiguous for the same (unqualified) name,
which does not help identify the failure.

Addresses PR31450!

llvm-svn: 290315
2016-12-22 04:26:57 +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
Richard Smith 151c456858 [c++1z] P0195R2: Support pack-expansion of using-declarations.
This change introduces UsingPackDecl as a marker for the set of UsingDecls
produced by pack expansion of a single (unresolved) using declaration. This is
not strictly necessary (we just need to be able to map from the original using
declaration to its expansions somehow), but it's useful to maintain the
invariant that each declaration reference instantiates to refer to one
declaration.

This is a re-commit of r290080 (reverted in r290092) with a fix for a
use-after-lifetime bug.

llvm-svn: 290203
2016-12-20 21:35:28 +00:00
Daniel Jasper 9068938eb0 Revert "[OpenCL] Enabling the usage of CLK_NULL_QUEUE as compare operand."
This reverts commit r290171. It triggers a bunch of warnings, because
the new enumerator isn't handled in all switches. We want a warning-free
build.

Replied on the commit with more details.

llvm-svn: 290173
2016-12-20 10:05:04 +00:00
Egor Churaev 67c3f3ec68 [OpenCL] Enabling the usage of CLK_NULL_QUEUE as compare operand.
Summary: Enabling the compression of CLK_NULL_QUEUE to variable of type queue_t.

Reviewers: Anastasia

Subscribers: cfe-commits, yaxunl, bader

Differential Revision: https://reviews.llvm.org/D27569

llvm-svn: 290171
2016-12-20 09:15:21 +00:00
Daniel Jasper 9949ead55a Revert "[c++1z] P0195R2: Support pack-expansion of using-declarations."
This reverts commit r290080 as it leads to many Clang crashes, e.g.:
http://lab.llvm.org:8011/builders/clang-cmake-aarch64-quick/builds/1814

llvm-svn: 290092
2016-12-19 10:09:25 +00:00
Richard Smith 22a250cd5d [c++1z] P0195R2: Support pack-expansion of using-declarations.
This change introduces UsingPackDecl as a marker for the set of UsingDecls
produced by pack expansion of a single (unresolved) using declaration. This is
not strictly necessary (we just need to be able to map from the original using
declaration to its expansions somehow), but it's useful to maintain the
invariant that each declaration reference instantiates to refer to one
declaration.

llvm-svn: 290080
2016-12-19 04:08:53 +00:00
Richard Smith d8a9e37558 Fix some interactions between C++11 and C++14 features and using-declarations:
* a dependent non-type using-declaration within a function template can be
   valid, as it can refer to an enumerator, so don't reject it in the template
   definition
 * we can partially substitute into a dependent using-declaration if it appears
   within a (local class in a) generic lambda within a function template, which
   means an UnresolvedUsing*Decl doesn't necessarily instantiate to a UsingDecl.

llvm-svn: 290071
2016-12-18 21:39:37 +00:00
Yaxun Liu 5b74665a41 Recommit r289979 [OpenCL] Allow disabling types and declarations associated with extensions
Fixed undefined behavior due to cast integer to bool in initializer list.

llvm-svn: 290056
2016-12-18 05:18:55 +00:00
Yaxun Liu 35f6d66b0d Revert r289979 due to regressions
llvm-svn: 289991
2016-12-16 21:23:55 +00:00
Yaxun Liu 2e8331cab6 [OpenCL] Allow disabling types and declarations associated with extensions
Added a map to associate types and declarations with extensions.

Refactored existing diagnostic for disabled types associated with extensions and extended it to declarations for generic situation.

Fixed some bugs for types associated with extensions.

Allow users to use pragma to declare types and functions for supported extensions, e.g.

#pragma OPENCL EXTENSION the_new_extension_name : begin
// declare types and functions associated with the extension here
#pragma OPENCL EXTENSION the_new_extension_name : end

Differential Revision: https://reviews.llvm.org/D21698

llvm-svn: 289979
2016-12-16 19:22:08 +00:00
Stephan Bergmann 17c7f70362 Replace APFloatBase static fltSemantics data members with getter functions
At least the plugin used by the LibreOffice build
(<https://wiki.documentfoundation.org/Development/Clang_plugins>) indirectly
uses those members (through inline functions in LLVM/Clang include files in turn
using them), but they are not exported by utils/extract_symbols.py on Windows,
and accessing data across DLL/EXE boundaries on Windows is generally
problematic.

Differential Revision: https://reviews.llvm.org/D26671

llvm-svn: 289647
2016-12-14 11:57:17 +00:00
George Burgess IV 215f6e788e [Sema] Prefer SmallVector over `new`ed memory blocks. NFC.
llvm-svn: 289571
2016-12-13 19:22:56 +00:00
Richard Smith b8c0f553ed DR1295 and cleanup for P0135R1: Make our initialization code more directly
mirror the description in the standard. Per DR1295, this means that binding a
const / rvalue reference to a bit-field no longer "binds directly", and per
P0135R1, this means that we materialize a temporary in reference binding
after adjusting cv-qualifiers and before performing a derived-to-base cast.

In C++11 onwards, this should have fixed the last case where we would
materialize a temporary of the wrong type (with a subobject adjustment inside
the MaterializeTemporaryExpr instead of outside), but we still have to deal
with that possibility in C++98, unless we want to start using xvalues to
represent materialized temporaries there too.

llvm-svn: 289250
2016-12-09 18:49:13 +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
Richard Smith 122f88d481 [c++17] P0135R1: Guaranteed copy elision.
When an object of class type is initialized from a prvalue of the same type
(ignoring cv qualifications), use the prvalue to initialize the object directly
instead of inserting a redundant elidable call to a copy constructor.

llvm-svn: 288866
2016-12-06 23:52:28 +00:00
George Burgess IV bc7f44cb28 [Sema] Reset a BumpPtrAllocator on clear(). NFC.
Looks like the reset() call was omitted by accident.

llvm-svn: 288534
2016-12-02 21:00:12 +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
George Burgess IV add6ab5084 Use the member function location in enable_if diagnostics.
Before:
<stdin>:3:3: error: no matching member function for call to 'bar'
  Foo().bar();
  ^

After:
<stdin>:3:9: error: no matching member function for call to 'bar'
  Foo().bar();
        ^

llvm-svn: 287154
2016-11-16 21:31:25 +00:00
George Burgess IV 0d546534d3 [Sema] Range-ify for loop, add period to comment. NFC.
llvm-svn: 286506
2016-11-10 21:47:12 +00:00
Richard Smith 9095e5bf7e p0012: Teach resolving address of overloaded function with dependent exception
specification to resolve the exception specification as part of the type check,
in C++1z onwards. This is not actually part of P0012 / CWG1330 rules for when
an exception specification is "needed", but is necessary for sanity.

llvm-svn: 285663
2016-11-01 01:31:23 +00:00
George Burgess IV d66d37cbd9 Make a function static. NFC.
llvm-svn: 285458
2016-10-28 21:42:06 +00:00
Richard Smith 1be59c5106 [c++1z] P0012R1: Implement a few remaining pieces: downgrade diagnostic for
mismatched dynamic exception specifications in expressions from an error to a
warning, since this is no longer ill-formed in C++1z.

Allow reference binding of a reference-to-non-noexcept function to a noexcept
function lvalue. As defect resolutions, also allow a conditional between
noexcept and non-noexcept function lvalues to produce a non-noexcept function
lvalue (rather than decaying to a function pointer), and allow function
template argument deduction to deduce a reference to non-noexcept function when
binding to a noexcept function type.

llvm-svn: 284905
2016-10-22 01:32:19 +00:00
Richard Smith ce76629905 Remove unnecessary distinction between Ref_Compatible and
Ref_Compatible_With_Added_Qualification. We always treated these two values the
same way.

llvm-svn: 284895
2016-10-21 23:01:55 +00:00
Richard Smith 5e9746f520 DR583, DR1512: Implement a rewrite to C++'s 'composite pointer type' rules.
This has two significant effects:

1) Direct relational comparisons between null pointer constants (0 and nullopt)
   and pointers are now ill-formed. This was always the case for C, and it
   appears that C++ only ever permitted by accident. For instance, cases like
     nullptr < &a
   are now rejected.

2) Comparisons and conditional operators between differently-cv-qualified
   pointer types now work, and produce a composite type that both source
   pointer types can convert to (when possible). For instance, comparison
   between 'int **' and 'const int **' is now valid, and uses an intermediate
   type of 'const int *const *'.

Clang previously supported #2 as an extension.

We do not accept the cases in #1 as an extension. I've tested a fair amount of
code to check that this doesn't break it, but if it turns out that someone is
relying on this, we can easily add it back as an extension.

This is a re-commit of r284800.

llvm-svn: 284890
2016-10-21 22:00:42 +00:00
Renato Golin 41189656ed Revert "DR583, DR1512: Implement a rewrite to C++'s 'composite pointer type' rules."
This reverts commit r284800, as it failed all ARM/AArch64 bots.

llvm-svn: 284811
2016-10-21 08:03:49 +00:00
Richard Smith 0c1c53e3fa DR583, DR1512: Implement a rewrite to C++'s 'composite pointer type' rules.
This has two significant effects:

1) Direct relational comparisons between null pointer constants (0 and nullopt)
   and pointers are now ill-formed. This was always the case for C, and it
   appears that C++ only ever permitted by accident. For instance, cases like
     nullptr < &a
   are now rejected.

2) Comparisons and conditional operators between differently-cv-qualified
   pointer types now work, and produce a composite type that both source
   pointer types can convert to (when possible). For instance, comparison
   between 'int **' and 'const int **' is now valid, and uses an intermediate
   type of 'const int *const *'.

Clang previously supported #2 as an extension.

We do not accept the cases in #1 as an extension. I've tested a fair amount of
code to check that this doesn't break it, but if it turns out that someone is
relying on this, we can easily add it back as an extension.

llvm-svn: 284800
2016-10-21 02:36:37 +00:00
Richard Smith eb7ef2e1ca Re-commit r284753, reverted in r284778, with a fix for PR30749.
Original commit message:

[c++1z] Teach composite pointer type computation how to compute the composite
pointer type of two function pointers with different noexcept specifications.
While I'm here, also teach it how to merge dynamic exception specifications.

llvm-svn: 284785
2016-10-20 21:53:09 +00:00
Hans Wennborg 2b81f42a76 Revert r284753 "[c++1z] Teach composite pointer type computation how to compute the composite"
It caused PR30749.

llvm-svn: 284778
2016-10-20 20:54:32 +00:00
Richard Smith 9c37e66c31 [c++1z] Teach composite pointer type computation how to compute the composite
pointer type of two function pointers with different noexcept specifications.
While I'm here, also teach it how to merge dynamic exception specifications.

llvm-svn: 284753
2016-10-20 17:57:33 +00:00
Richard Smith 6f42740707 Fix crash on noreturn conversion in unprototyped function type. Thanks to Keith
Walker for spotting the bug.

llvm-svn: 284673
2016-10-20 00:01:36 +00:00
Richard Smith 5f4b388442 Resolve exception specifications when selecting an overloaded operator.
llvm-svn: 284556
2016-10-19 00:14:23 +00:00
Richard Smith 84a0b6dba1 DR1330: instantiate exception-specifications when "needed". We previously did
not instantiate exception specifications of functions if they were only used in
unevaluated contexts (other than 'noexcept' expressions).

In C++17 onwards, this becomes essential since the exception specification is
now part of the function's type.

Note that this means that constructs like the following no longer work:

  struct A {
    static T f() noexcept(...);
    decltype(f()) *p;
  };

... because the decltype expression now needs the exception specification of
'f', which has not yet been parsed.

llvm-svn: 284549
2016-10-18 23:39:12 +00:00
Richard Smith 3c4f8d2e96 P0012R1: Make exception specifications be part of the type system. This
implements the bulk of the change (modifying the type system to include
exception specifications), but not all the details just yet.

llvm-svn: 284337
2016-10-16 17:54:23 +00:00
Richard Smith b2f0f05742 Re-commit r283722, reverted in r283750, with a fix for a CUDA-specific use of
past-the-end iterator.

Original commit message:

P0035R4: Semantic analysis and code generation for C++17 overaligned
allocation.

llvm-svn: 283789
2016-10-10 18:54:32 +00:00
Daniel Jasper e9abe64816 Revert "P0035R4: Semantic analysis and code generation for C++17 overaligned allocation."
This reverts commit r283722. Breaks:
  Clang.SemaCUDA.device-var-init.cu
  Clang.CodeGenCUDA.device-var-init.cu

http://lab.llvm.org:8080/green/job/clang-stage1-cmake-RA-expensive/884/

llvm-svn: 283750
2016-10-10 14:13:55 +00:00
Richard Smith 189e52fcdf P0035R4: Semantic analysis and code generation for C++17 overaligned
allocation.

llvm-svn: 283722
2016-10-10 06:42:31 +00:00
Richard Smith e15a370084 PR25890: Fix incoherent error handling in PerformImplicitConversion and
CheckSingleAssignmentConstraints. These no longer produce ExprError() when they
have not emitted an error, and reliably inform the caller when they *have*
emitted an error.

This fixes some serious issues where we would fail to emit any diagnostic for
invalid code and then attempt to emit code for an invalid AST, and conversely
some issues where we would emit two diagnostics for the same problem.

llvm-svn: 283508
2016-10-06 23:12:58 +00:00
Justin Lebar 53b000afc2 [CUDA] Clean up some comments in Sema::IsOverload. NFC
llvm-svn: 283121
2016-10-03 16:48:27 +00:00
Justin Lebar e060feb7b1 [CUDA] Disallow overloading destructors.
Summary:
We'd attempted to allow this, but turns out we were doing a very bad
job.  :)

Making this work properly would be a giant change in clang.  For
example, we'd need to make CXXRecordDecl::getDestructor()
context-sensitive, because the destructor you end up with depends on
where you're calling it from.

For now (and hopefully for ever), just disallow overloading of
destructors in CUDA.

Reviewers: rsmith

Subscribers: cfe-commits, tra

Differential Revision: https://reviews.llvm.org/D24571

llvm-svn: 283120
2016-10-03 16:48:23 +00:00
George Burgess IV fbad5b2f1b [Sema] Compare bad conversions in overload resolution.
r280553 introduced an issue where we'd emit ambiguity errors for code
like:

```
void foo(int *, int);
void foo(unsigned int *, unsigned int);

void callFoo() {
  unsigned int i;
  foo(&i, 0); // ambiguous: int->unsigned int is worse than int->int,
              // but unsigned int*->unsigned int* is better than
              // int*->int*.
}
```

This patch fixes this issue by changing how we handle ill-formed (but
valid) implicit conversions. Candidates with said conversions now always
rank worse than candidates without them, and two candidates are
considered to be equally bad if they both have these conversions for
the same argument.

Additionally, this fixes a case in C++11 where we'd complain about an
ambiguity in a case like:

```
void f(char *, int);
void f(const char *, unsigned);
void g() { f("abc", 0); }
```

...Since conversion to char* from a string literal is considered
ill-formed in C++11 (and deprecated in C++03), but we accept it as an
extension.

llvm-svn: 280847
2016-09-07 20:03:19 +00:00
Ismail Pazarbasi 4a00774e59 Try contextually converting condition of constexpr if to Boolean value
Summary:
C++1z 6.4.1/p2:
 If the if statement is of the form if constexpr, the value of the
 condition shall be a contextually converted constant expression of type
 bool [...]
C++1z 5.20/p4:
 [...] A contextually converted constant expression of type bool is an
 expression, contextually converted to bool (Clause4), where the
 converted expression is a constant expression and the conversion
 sequence contains only the conversions above. [...]

Contextually converting result of an expression `e` to a Boolean value
requires `bool t(e)` to be well-formed.

An explicit conversion function is only considered as a user-defined
conversion for direct-initialization, which is essentially what
//contextually converted to bool// requires.

Also, fixes PR28470.

Reviewers: rsmith

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D24158

llvm-svn: 280838
2016-09-07 18:24:54 +00:00
George Burgess IV 6098fd1989 [Sema] Fix how we set implicit conversion kinds.
We have invariants we like to guarantee for the
`ImplicitConversionKind`s in a `StandardConversionSequence`. These
weren't being upheld in code that r280553 touched, so Richard suggested
that we should fix that. See D24113.

I'm not entirely sure how to go about testing this, so no test case is
included. Suggestions welcome.

llvm-svn: 280562
2016-09-03 00:28:25 +00:00
George Burgess IV 2099b54102 [Sema] Relax overloading restrictions in C.
This patch allows us to perform incompatible pointer conversions when
resolving overloads in C. So, the following code will no longer fail to
compile (though it will still emit warnings, assuming the user hasn't
opted out of them):

```
void foo(char *) __attribute__((overloadable));
void foo(int) __attribute__((overloadable));

void callFoo() {
  unsigned char bar[128];
  foo(bar); // selects the char* overload.
}
```

These conversions are ranked below all others, so:

  A. Any other viable conversion will win out
  B. If we had another incompatible pointer conversion in the example
     above (e.g. `void foo(int *)`), we would complain about
     an ambiguity.

Differential Revision: https://reviews.llvm.org/D24113

llvm-svn: 280553
2016-09-02 22:59:57 +00:00
Aaron Ballman 8b871d96d7 Based on post-commit feedback over IRC with dblaikie, ideally, we should have a SmallVector constructor that accepts anything which can supply a range via ADL begin()/end() calls so that we can construct the SmallVector directly from anything range-like.
Since that doesn't exist right now, use a local variable instead of calling getAssocExprs() twice; NFC.

llvm-svn: 280520
2016-09-02 18:31:31 +00:00
Aaron Ballman ff7bd8bacd Allow a C11 generic selection expression to select a function with the overloadable attribute as the result expression without crashing. This fixes PR30201.
llvm-svn: 280483
2016-09-02 13:45:40 +00:00
Justin Lebar 18e2d82297 [CUDA] Raise an error if a wrong-side call is codegen'ed.
Summary:
Some function calls in CUDA are allowed to appear in
semantically-correct programs but are an error if they're ever
codegen'ed.  Specifically, a host+device function may call a host
function, but it's an error if such a function is ever codegen'ed in
device mode (and vice versa).

Previously, clang made no attempt to catch these errors.  For the most
part, they would be caught by ptxas, and reported as "call to unknown
function 'foo'".

Now we catch these errors and report them the same as we report other
illegal calls (e.g. a call from a host function to a device function).

This has a small change in error-message behavior for calls that were
previously disallowed (e.g. calls from a host to a device function).
Previously, we'd catch disallowed calls fairly early, before doing
additional semantic checking e.g. of the call's arguments.  Now we catch
these illegal calls at the very end of our semantic checks, so we'll
only emit a "illegal CUDA call" error if the call is otherwise
well-formed.

Reviewers: tra, rnk

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D23242

llvm-svn: 278759
2016-08-15 23:00:49 +00:00
George Burgess IV 458b3f3a11 [Sema] Fix the wording of a comment. NFC.
llvm-svn: 278472
2016-08-12 04:19:35 +00:00
George Burgess IV 53b938da5a [Sema] Fix a crash on variadic enable_if functions.
Currently, when trying to evaluate an enable_if condition, we try to
evaluate all arguments a user passes to a function. Given that we can't
use variadic arguments from said condition anyway, not converting them
is a reasonable thing to do. So, this patch makes us ignore any varargs
when attempting to check an enable_if condition.

We'd crash because, in order to convert an argument, we need its
ParmVarDecl. Variadic arguments don't have ParmVarDecls.

llvm-svn: 278471
2016-08-12 04:12:31 +00:00
Justin Lebar 7d078bddbd [CUDA] Print a "previous-decl" note when calling an illegal member fn.
Summary:
When we emit err_ref_bad_target, we should emit a "'method' declared
here" note.  We already do so in most places, just not in
BuildCallToMemberFunction.

Reviewers: tra

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D23240

llvm-svn: 278195
2016-08-10 01:09:18 +00:00
Justin Lebar b008003aa3 [CUDA] Rename CheckCUDATarget to IsAllowedCUDACall. NFC
Summary:
I want to reuse "CheckCUDAFoo" in a later patch.  Also, I think
IsAllowedCUDACall gets the point across more clearly.

Reviewers: tra

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D23238

llvm-svn: 278193
2016-08-10 01:09:11 +00:00
Justin Lebar 66a2ab9175 [CUDA] Minor comment nits.
llvm-svn: 278183
2016-08-10 00:40:43 +00:00
George Burgess IV 21081364f8 [Sema] Replace mem_fn with lambdas. NFC.
I'm told that some optimizers like lambdas a lot more than mem_fn.
Given that the readability difference is basically nil, and we seem to
use lambdas basically everywhere else, it seems sensible to just use
lambdas.

llvm-svn: 276577
2016-07-24 23:12:40 +00:00
Dmitry Polukhin ba57f02720 Deprecated (legacy) string literal conversion to 'char *' causes strange overloading resolution
It's a patch for PR28050. Seems like overloading resolution wipes out
the first standard conversion sequence (before user-defined conversion)
in case of deprecated string literal conversion.

Differential revision: https://reviews.llvm.org/D21228

Patch by Alexander Makarov

llvm-svn: 275970
2016-07-19 11:29:16 +00:00
Justin Lebar d35f706cc2 [CUDA] Don't assume that destructors can't be overloaded.
Summary:
You can overload a destructor in CUDA, and SemaOverload needs to be
tweaked not to crash when it sees an explicit call to an overloaded
destructor.

Reviewers: rsmith

Subscribers: cfe-commits, tra

Differential Revision: http://reviews.llvm.org/D21912

llvm-svn: 275231
2016-07-12 23:23:01 +00:00
David Majnemer 02d57cc92c [MS ABI] Pick an inheritance model if we resolve an overload set
We didn't assign an inheritance model for 'Foo' if the event an
exrepssion like '&Foo::Bar' occured if 'Bar' could resolve to multiple
functions.

Once the overload set is resolved to a particular member, we enforce a
specific inheritance model.

This fixes PR28360.

llvm-svn: 274202
2016-06-30 03:02:03 +00:00
Richard Smith 5179eb7821 P0136R1, DR1573, DR1645, DR1715, DR1736, DR1903, DR1941, DR1959, DR1991:
Replace inheriting constructors implementation with new approach, voted into
C++ last year as a DR against C++11.

Instead of synthesizing a set of derived class constructors for each inherited
base class constructor, we make the constructors of the base class visible to
constructor lookup in the derived class, using the normal rules for
using-declarations.

For constructors, UsingShadowDecl now has a ConstructorUsingShadowDecl derived
class that tracks the requisite additional information. We create shadow
constructors (not found by name lookup) in the derived class to model the
actual initialization, and have a new expression node,
CXXInheritedCtorInitExpr, to model the initialization of a base class from such
a constructor. (This initialization is special because it performs real perfect
forwarding of arguments.)

In cases where argument forwarding is not possible (for inalloca calls,
variadic calls, and calls with callee parameter cleanup), the shadow inheriting
constructor is not emitted and instead we directly emit the initialization code
into the caller of the inherited constructor.

Note that this new model is not perfectly compatible with the old model in some
corner cases. In particular:
 * if B inherits a private constructor from A, and C uses that constructor to
   construct a B, then we previously required that A befriends B and B
   befriends C, but the new rules require A to befriend C directly, and
 * if a derived class has its own constructors (and so its implicit default
   constructor is suppressed), it may still inherit a default constructor from
   a base class

llvm-svn: 274049
2016-06-28 19:03:57 +00:00
David Majnemer a3debed239 Use even more ArrayRefs
No functional change is intended, just a small refactoring.

llvm-svn: 273650
2016-06-24 05:33:44 +00:00
George Burgess IV beca4a3338 [Sema] Teach CheckPlaceholderExpr about unaddressable functions.
Given the following C++:

```
void foo();
void foo() __attribute__((enable_if(false, "")));

bool bar() {
  auto P = foo;
  return P == foo;
}
```

We'll currently happily (and correctly) resolve `foo` to the `foo`
overload without `enable_if` when assigning to `P`. However, we'll
complain about an ambiguous overload on the `P == foo` line, because
`Sema::CheckPlaceholderExpr` doesn't recognize that there's only one
`foo` that could possibly work here.

This patch teaches `Sema::CheckPlaceholderExpr` how to properly deal
with such cases.

Grepping for other callers of things like
`Sema::ResolveAndFixSingleFunctionTemplateSpecialization`, it *looks*
like this is the last place that needed to be fixed up. If I'm wrong,
I'll see if there's something we can do that beats what amounts to
whack-a-mole with bugs.

llvm-svn: 272080
2016-06-08 00:34:22 +00:00
Richard Smith c2bebe9aca Preserve the FoundDecl when performing overload resolution for constructors.
This is in preparation for C++ P0136R1, which switches the model for inheriting
constructors over from synthesizing a constructor to finding base class
constructors (via using shadow decls) when looking for derived class
constructors.

llvm-svn: 269231
2016-05-11 20:37:46 +00:00
Andrey Bokhanko 45d413260e [MSVC] Implementation of __unaligned as a proper type qualifier
This patch implements __unaligned (MS extension) as a proper type qualifier
(before that, it was implemented as an ignored attribute).

It also fixes PR27367 and PR27666.

Differential Revision: http://reviews.llvm.org/D20103

llvm-svn: 269220
2016-05-11 18:38:21 +00:00
George Burgess IV e8f10cc0b9 [Sema] Fix value-dependent enable_if bug.
This patch fixes a bug where we would assume all value-dependent
enable_if conditions give successful results.

Instead, we consider value-dependent enable_if conditions to always
fail. While this isn't ideal, this is the best we can realistically do
without changing both enable_if's semantics and large parts of Sema
(specifically, all of the parts that don't expect type dependence to
come out of nowhere, and that may interact with overload resolution).

Differential Revision: http://reviews.llvm.org/D20130

llvm-svn: 269154
2016-05-11 01:38:27 +00:00
George Burgess IV 3dc1669133 [Sema] Fix an overload resolution bug with enable_if.
Currently, if clang::isBetterOverloadCandidate encounters an enable_if
attribute on either candidate that it's inspecting, it will ignore all
lower priority attributes (e.g. pass_object_size). This is problematic
in cases like:

```
void foo(char *c) __attribute__((enable_if(1, "")));
void foo(char *c __attribute__((pass_object_size(0))))
    __attribute__((enable_if(1, "")));
```

...Because we would ignore the pass_object_size attribute in the second
`foo`, and consider any call to `foo` to be ambiguous.

This patch makes overload resolution consult further tiebreakers (e.g.
pass_object_size) if two candidates have equally good enable_if
attributes.

llvm-svn: 269005
2016-05-10 01:59:34 +00:00
Nemanja Ivanovic bb1ea2d613 Enable support for __float128 in Clang and enable it on pertinent platforms
This patch corresponds to reviews:
http://reviews.llvm.org/D15120
http://reviews.llvm.org/D19125

It adds support for the __float128 keyword, literals and target feature to
enable it. Based on the latter of the two aforementioned reviews, this feature
is enabled on Linux on i386/X86 as well as SystemZ.
This is also the second attempt in commiting this feature. The first attempt
did not enable it on required platforms which caused failures when compiling
type_traits with -std=gnu++11.

If you see failures with compiling this header on your platform after this
commit, it is likely that your platform needs to have this feature enabled.

llvm-svn: 268898
2016-05-09 08:52:33 +00:00
Nico Weber 2801d32c07 Revert r268727, it caused PR27666.
llvm-svn: 268736
2016-05-06 14:34:29 +00:00
Andrey Bokhanko ba0d7540e3 [MSVC] Implementation of __unaligned as a proper type qualifier
This patch implements __unaligned (MS extension) as a proper type qualifier
(before that, it was implemented as an ignored attribute).

It also fixes PR27367.

Differential Revision: http://reviews.llvm.org/D19654

llvm-svn: 268727
2016-05-06 11:47:55 +00:00
George Burgess IV f23ce3609b [Sema] Specify the underlying type for an enum. NFC.
llvm-svn: 268113
2016-04-29 21:32:53 +00:00
Serge Pavlov 7dcc97e7ac Warn if function or variable cannot be implicitly instantiated
With this patch compiler emits warning if it tries to make implicit instantiation
of a template but cannot find the template definition. The warning can be suppressed
by explicit instantiation declaration or by command line options
-Wundefined-var-template and -Wundefined-func-template. The implementation follows
the discussion of http://reviews.llvm.org/D12326.

Differential Revision: http://reviews.llvm.org/D16396

llvm-svn: 266719
2016-04-19 06:19:52 +00:00
Nemanja Ivanovic d7d45bf8ce Revert 266186 as it breaks anything that includes type_traits on some platforms
Since this patch provided support for the __float128 type but disabled it
on all platforms by default, some platforms can't compile type_traits with
-std=gnu++11 since there is a specialization with __float128.
This reverts the patch until D19125 is approved (i.e. we know which platforms
need this support enabled).

llvm-svn: 266460
2016-04-15 18:04:13 +00:00
Nemanja Ivanovic 50f29e06a1 Enable support for __float128 in Clang
This patch corresponds to review:
http://reviews.llvm.org/D15120

It adds support for the __float128 keyword, literals and a target feature to
enable it. This support is disabled by default on all targets and any target
that has support for this type is free to add it.

Based on feedback that I've received from target maintainers, this appears to
be the right thing for most targets. I have not heard from the maintainers of
X86 which I believe supports this type. I will subsequently investigate the
impact of enabling this on X86.

llvm-svn: 266186
2016-04-13 09:49:45 +00:00
Benjamin Kramer 5ff6747e04 Remove redundant conditions of the form (A || (!A && B)) -> (A || B)
Found by cppcheck! PR27286 PR27287 PR27288 PR27289

llvm-svn: 265918
2016-04-11 08:26:13 +00:00
Manman Ren d2a3cd7261 NFC: simplify code in BuildInstanceMessage.
Instead of searching the global pool multiple times: in
LookupFactoryMethodInGlobalPool, LookupInstanceMethodInGlobalPool,
CollectMultipleMethodsInGlobalPool, and AreMultipleMethodsInGlobalPool,
we now collect the method candidates in CollectMultipleMethodsInGlobalPool
only, and other functions will use the collected method set.

This commit adds parameter "Methods" to AreMultipleMethodsInGlobalPool,
and SelectBestMethod. It also changes the implementation of
CollectMultipleMethodsInGlobalPool to collect the desired kind first, if none is
found, to collect the other kind. This avoids the need to call both
LookupFactoryMethodInGlobalPool and LookupInstanceMethodInGlobalPool.

llvm-svn: 265711
2016-04-07 19:30:20 +00:00
Justin Lebar ba122ab42f [CUDA] Make unattributed constexpr functions implicitly host+device.
With this patch, by a constexpr function is implicitly host+device
unless:

 a) it's a variadic function (variadic functions are not allowed on the
    device side), or
 b) it's preceeded by a __device__ overload in a system header.

The restriction on overloading __host__ __device__ functions on the
basis of their CUDA attributes remains in place, but we use (b) to allow
us to define __device__ overloads for constexpr functions in cmath,
which would otherwise be __host__ __device__ and thus not overloadable.

You can disable this behavior with -fno-cuda-host-device-constexpr.

Reviewers: tra, rnk, rsmith

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D18380

llvm-svn: 264964
2016-03-30 23:30:21 +00:00
Justin Lebar 39fd529935 [Sema] s/UseUsingDeclRules/UseMemberUsingDeclRules/
Summary:
IsOverload has a param named UseUsingDeclRules.  But as far as I can
tell, it should be called UseMemberUsingDeclRules.  That is, it only
applies to "using" declarations inside classes or structs.

Reviewers: rsmith

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D18538

llvm-svn: 264920
2016-03-30 20:41:05 +00:00
Justin Lebar 25c4a81e79 [CUDA] Remove three obsolete CUDA cc1 flags.
Summary:
* -fcuda-target-overloads

  Previously unconditionally set to true by the driver.  Necessary for
  correct functioning of the compiler -- our CUDA headers wrapper won't
  compile without this.

* -fcuda-disable-target-call-checks

  Previously unconditionally set to true by the driver.  Necessary to
  compile almost any external CUDA code -- almost all libraries assume
  that host+device code can call host or device functions.

* -fcuda-allow-host-calls-from-host-device

  No effect when target overloading is enabled.

Reviewers: tra

Subscribers: rsmith, cfe-commits

Differential Revision: http://reviews.llvm.org/D18416

llvm-svn: 264739
2016-03-29 16:24:16 +00:00
Richard Smith ed638864d3 P0138R2: Allow direct-list-initialization of an enumeration from an integral
value that can convert to the enum's underlying type.

llvm-svn: 264564
2016-03-28 06:08:37 +00:00
Richard Smith 95853077c3 Fix nondeterminism in computation of builtin operator overload sets.
llvm-svn: 264363
2016-03-25 00:08:53 +00:00
George Burgess IV 6da4c20f7d [Sema] Allow implicit conversions of &overloaded_fn in C.
Also includes a minor ``enable_if`` docs update.

Currently, our address-of overload machinery will only allow implicit
conversions of overloaded functions to void* in C. For example:

```
void f(int) __attribute__((overloadable));
void f(double) __attribute__((overloadable, enable_if(0, "")));

void *fp = f; // OK. This is C and the target is void*.
void (*fp2)(void) = f; // Error. This is C, but the target isn't void*.
```

This patch makes the assignment of `fp2` select the `f(int)` overload,
rather than emitting an error (N.B. you'll still get a warning about the
`fp2` assignment if you use -Wincompatible-pointer-types).

Differential Revision: http://reviews.llvm.org/D13704

llvm-svn: 264132
2016-03-23 02:33:58 +00:00
George Burgess IV 3cde9bf9d5 [Sema] Allow casting of some overloaded functions
Some functions can't have their address taken. If we encounter an
overload set where only one of the candidates can have its address
taken, we should automatically select that candidate in cast
expressions.

Differential Revision: http://reviews.llvm.org/D17701

llvm-svn: 263887
2016-03-19 21:36:10 +00:00