When we have template arguments, we have a function and a pattern, the variable
in init-capture belongs to the pattern decl when checking if the lhs of
"max = current" is modifiable:
auto find = [max = init](auto current) {
max = current;
};
In function isReferenceToNonConstCapture, we handle the case where the decl
context for the variable is not part of the current context.
Instead of crashing, we emit an error message:
cannot assign to a variable captured by copy in a non-mutable lambda
rdar://26997922
llvm-svn: 274392
This patch adds a __nth_element builtin that allows fetching the n-th type of a
parameter pack with very little compile-time overhead. The patch was inspired by
r252036 and r252115 by David Majnemer, which add a similar __make_integer_seq
builtin for efficiently creating a std::integer_sequence.
Reviewed as D15421. http://reviews.llvm.org/D15421
llvm-svn: 274316
function-style cast to a non-dependent type which is then used in an invalid
way. We'd lose the "type dependent" bit here, and downstream Sema processing
would then discard the expression if it was used in a context where its type
rendered it invalid.
llvm-svn: 274267
Original patch by Stefan Bühler http://reviews.llvm.org/D12834
Difference between original and this one:
- fixed all failing tests
- fixed mangling for global variable outside namespace
- emit ABI tags for guards and local names
- clang-format + other stylistic changes
- significantly reworked patch according to Richard's suggestions
Sema part, committed before http://reviews.llvm.org/D17567
Differential revision: http://reviews.llvm.org/D18035
llvm-svn: 274222
Summary:
Summary:
Change Clang calling convention SpirKernel to OpenCLKernel.
Set calling convention OpenCLKernel for amdgcn as well.
Add virtual method .getOpenCLKernelCallingConv() to TargetCodeGenInfo
and use it to set target calling convention for AMDGPU and SPIR.
Update tests.
Reviewers: rsmith, tstellarAMD, Anastasia, yaxunl
Subscribers: kzhuravl, cfe-commits
Differential Revision: http://reviews.llvm.org/D21367
llvm-svn: 274220
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
No semantic analysis yet.
This is a pain to disambiguate correctly, because the parsing rules for the
declaration form of a condition and of an init-statement are quite different --
for a token sequence that looks like a declaration, we frequently need to
disambiguate all the way to the ')' or ';'.
We could do better here in some cases by stopping disambiguation once we've
decided whether we've got an expression or not (rather than keeping going until
we know whether it's an init-statement declaration or a condition declaration),
by unifying our parsing code for the two types of declaration and moving the
syntactic checks into Sema; if this has a measurable impact on parsing
performance, I'll look into that.
llvm-svn: 274169
Reverts r273305 and re-instates r273296.
We needed to fix a bug in Sema::MarkVTableUsed to ensure that operator
delete lookup occurs when the vtable is referenced. We already had a
special case to look up operator delete when dllimport was used, but I
think should really mark virtual destructors referenced any time the
vtable is used.
llvm-svn: 274147
constructor would be; this is effectively required by P0136R1. This has the
effect of exposing the validity of the base class initialization steps to
SFINAE checks.
llvm-svn: 274088
When a class property is accessed with an object instance, before this commit,
we try to apply a typo correction of the same property:
property 'c' not found on object of type 'A *'; did you mean 'c'?
With this commit, we correctly emit a diagnostics:
property 'c' is a class property; did you mean to access it with class 'A'?
rdar://26866973
llvm-svn: 274076
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
[OpenMP] Initial implementation of parse and sema for composite pragma 'distribute parallel for'
This patch is an initial implementation for #distribute parallel for.
The main differences that affect other pragmas are:
The implementation of 'distribute parallel for' requires blocking of the associated loop, where blocks are "distributed" to different teams and iterations within each block are scheduled to parallel threads within each team. To implement blocking, sema creates two additional worksharing directive fields that are used to pass the team assigned block lower and upper bounds through the outlined function resulting from 'parallel'. In this way, scheduling for 'for' to threads can use those bounds.
As a consequence of blocking, the stride of 'distribute' is not 1 but it is equal to the blocking size. This is returned by the runtime and sema prepares a DistIncrExpr variable to hold that value.
As a consequence of blocking, the global upper bound (EnsureUpperBound) expression of the 'for' is not the original loop upper bound (e.g. in for(i = 0 ; i < N; i++) this is 'N') but it is the team-assigned block upper bound. Sema creates a new expression holding the calculation of the actual upper bound for 'for' as UB = min(UB, PrevUB), where UB is the loop upper bound, and PrevUB is the team-assigned block upper bound.
llvm-svn: 273884
http://reviews.llvm.org/D21564
This patch is an initial implementation for #distribute parallel for.
The main differences that affect other pragmas are:
The implementation of 'distribute parallel for' requires blocking of the associated loop, where blocks are "distributed" to different teams and iterations within each block are scheduled to parallel threads within each team. To implement blocking, sema creates two additional worksharing directive fields that are used to pass the team assigned block lower and upper bounds through the outlined function resulting from 'parallel'. In this way, scheduling for 'for' to threads can use those bounds.
As a consequence of blocking, the stride of 'distribute' is not 1 but it is equal to the blocking size. This is returned by the runtime and sema prepares a DistIncrExpr variable to hold that value.
As a consequence of blocking, the global upper bound (EnsureUpperBound) expression of the 'for' is not the original loop upper bound (e.g. in for(i = 0 ; i < N; i++) this is 'N') but it is the team-assigned block upper bound. Sema creates a new expression holding the calculation of the actual upper bound for 'for' as UB = min(UB, PrevUB), where UB is the loop upper bound, and PrevUB is the team-assigned block upper bound.
llvm-svn: 273705
-Wfor-loop-analysis warnings for a for-loop with a condition variable. In such
a case, the loop condition variable is modified on each iteration of the loop
by definition.
Original commit message:
Rearrange condition handling so that semantic checks on a condition variable
are performed before the other substatements of the construct are parsed,
rather than deferring them until the end. This allows better error recovery
from semantic errors in the condition, improves diagnostic order, and is a
prerequisite for C++17 constexpr if.
llvm-svn: 273600
are performed before the other substatements of the construct are parsed,
rather than deferring them until the end. This allows better error recovery
from semantic errors in the condition, improves diagnostic order, and is a
prerequisite for C++17 constexpr if.
llvm-svn: 273548
(currently theoretical) bug where recursive calls to BuildScopeInformation
would do the wrong thing if the type of the statement is one of the kinds with
special handling, but this is not currently observable because the relevant
recursive calls happen to all be for CompoundStmts. (This becomes visible with
the C++17 'constexpr if' feature, where we get a protected scope for the 'then'
/ 'else' cases of some 'if's, and don't necessarily have a corresponding
compound statement.)
llvm-svn: 273309
- In functions with try { } catch { }, only the try block would be
skipped, not the catch blocks
- The template functions would still be parsed.
- The initializers within a constructor would still be parsed.
- The inline functions within class would still be stored, only to be
discared later.
- Invalid code with try would assert (as in "int foo() try assert_here")
This attempt to do even less while skipping function bodies.
Differential Revision: http://reviews.llvm.org/D20821
llvm-svn: 272963
This code should be an error:
void foo(int);
void f3() {
int foo(float);
{
float foo(int); // expected-error {{functions that differ only in their return type cannot be overloaded}}
}
}
the foo(float) function declared at function scope should not hide the float(int)
while trying to redeclare functions.
Differential Revision: http://reviews.llvm.org/D19763
llvm-svn: 272961
instantiation.
Added checks for non-dependent context when trygin to capture
non-constant schedule chunk expression for proper codegen of outlined
functions.
llvm-svn: 272775
classes.
MSVC actively uses unqualified lookup in dependent bases, lookup at the
instantiation point (non-dependent names may be resolved on things
declared later) etc. and all this stuff is the main cause of
incompatibility between clang and MSVC.
Clang tries to emulate MSVC behavior but it may fail in many cases.
clang could store lexed tokens for member functions definitions within
ClassTemplateDecl for later parsing during template instantiation.
It will allow resolving many possible issues with lookup in dependent
base classes and removing many already existing MSVC-specific
hacks/workarounds from the clang code.
llvm-svn: 272774
Summary:
This is similar to other loop pragmas like 'vectorize'. Currently it
only has state values: distribute(enable) and distribute(disable). When
one of these is specified the corresponding loop metadata is generated:
!{!"llvm.loop.distribute.enable", i1 true/false}
As a result, loop distribution will be attempted on the loop even if
Loop Distribution in not enabled globally. Analogously, with 'disable'
distribution can be turned off for an individual loop even when the pass
is otherwise enabled.
There are some slight differences compared to the existing loop pragmas.
1. There is no 'assume_safety' variant which makes its handling slightly
different from 'vectorize'/'interleave'.
2. Unlike the existing loop pragmas, it does not have a corresponding
numeric pragma like 'vectorize' -> 'vectorize_width'. So for the
consistency checks in CheckForIncompatibleAttributes we don't need to
check it against other pragmas. We just need to check for duplicates of
the same pragma.
Reviewers: rsmith, dexonsmith, aaron.ballman
Subscribers: bob.wilson, cfe-commits, hfinkel
Differential Revision: http://reviews.llvm.org/D19403
llvm-svn: 272656
See https://llvm.org/bugs/show_bug.cgi?id=28100.
In r266561 when I implemented allowing explicit specializations of function templates to override deleted status, I mistakenly assumed (and hence introduced a violable assertion) that when an explicit specialization was being declared, the corresponding specialization of the most specialized function template that it would get linked to would always be the one that was implicitly generated - and so if it was marked as 'deleted' it must have inherited it from the primary template and so should be safe to reset its deleted status, and set it to being an explicit specialization. Obviously during redeclaration of a deleted explicit specialization, in order to avoid a recursive reset, we need to check that the previous specialization is not an explicit specialization (instead of assuming and asserting it) and that it hasn't been referenced, and so only then is it safe to reset its 'deleted' status.
All regression tests pass.
Thanks to Zhendong Su for reporting the bug and David Majnemer for tracking it to my commit r266561, and promptly bringing it to my attention.
llvm-svn: 272631
If definition of default function argument uses itself, clang crashed,
because corresponding function parameter is not associated with the default
argument yet. With this fix clang emits appropriate error message.
This change fixes PR28105.
Differential Revision: http://reviews.llvm.org/D21301
llvm-svn: 272623
This patch implements PR#22821.
Taking the address of a packed member is dangerous since the reduced
alignment of the pointee is lost. This can lead to memory alignment
faults in some architectures if the pointer value is dereferenced.
This change adds a new warning to clang emitted when taking the address
of a packed member. A packed member is either a field/data member
declared as attribute((packed)) or belonging to a struct/class
declared as such. The associated flag is -Waddress-of-packed-member
Differential Revision: http://reviews.llvm.org/D20561
llvm-svn: 272552
The bug report by Gonzalo (https://llvm.org/bugs/show_bug.cgi?id=27507 -- which results in clang crashing when generic lambdas that capture 'this' are instantiated in contexts where the Functionscopeinfo stack is not in a reliable state - yet getCurrentThisType expects it to be) - unearthed some additional bugs in regards to maintaining proper cv qualification through 'this' when performing by value captures of '*this'.
This patch attempts to correct those bugs and makes the following changes:
o) when capturing 'this', we do not need to remember the type of 'this' within the LambdaScopeInfo's Capture - it is never really used for a this capture - so remove it.
o) teach getCurrentThisType to walk the stack of lambdas (even in scenarios where we run out of LambdaScopeInfo's such as when instantiating call operators) looking for by copy captures of '*this' and resetting the type of 'this' based on the constness of that capturing lambda's call operator.
This patch has been baking in review-hell for > 6 weeks - all the comments so far have been addressed and the bug (that it addresses in passing, and I regret not submitting as a separate patch initially) has been reported twice independently, so is frequent and important for us not to just sit on. I merged the cv qualification-fix and the PR-fix initially in one patch, since they resulted from my initial implementation of star-this and so were related. If someone really feels strongly, I can put in the time to revert this - separate the two out - and recommit. I won't claim it's immunized against all bugs, but I feel confident enough about the fix to land it for now.
llvm-svn: 272480
We shouldn't return true from CheckSpecifiedExceptionType if
the record type is incomplete and -fms-extensions is engaged. Otherwise
we will have an incomplete AST.
llvm-svn: 272447
Microsoft headers, comdef.h and comutil.h, assume that this is an OK
thing to do. Downgrade the hard error to a warning if we are in
-fms-extensions mode.
This fixes PR28080.
llvm-svn: 272412
Crash reported in PR28023 is caused by the fact that non-type template
parameters are found by tag name lookup. In the code provided in that PR:
template<int V> struct A {
struct B {
template <int> friend struct V;
};
};
the template parameter V is found when lookup for redeclarations of 'struct V'
is made. Latter on the error about shadowing of 'V' is emitted but the semantic
context of 'struct V' is already determined wrong: 'struct A' instead of
translation unit.
The fix moves the check for shadowing toward the beginning of the method and
thus prevents from wrong context calculations.
This change fixes PR28023.
llvm-svn: 272366
Summary:
Create a new Frontend LangOpt to specify the renderscript language. It
is enabled by the "-x renderscript" option from the driver.
Add a "kernel" function attribute only for RenderScript (an "ignored
attribute" warning is generated otherwise).
Make the NativeHalfType and NativeHalfArgsAndReturns LangOpts be implied
by the RenderScript LangOpt.
Reviewers: rsmith
Subscribers: cfe-commits, srhines
Differential Revision: http://reviews.llvm.org/D21198
llvm-svn: 272342
These ExprWithCleanups are added for holding a RunCleanupsScope not
for destructor calls; rather, they are for lifetime marks. This requires
ExprWithCleanups to keep a bit to indicate whether it have cleanups with
side effects (e.g. dtor calls).
Differential Revision: http://reviews.llvm.org/D20498
llvm-svn: 272296
It is possible for a field and a class to have the same name. In such
cases, performing lookup for the field might return a result set with
more than one entry. An overzealous assertion fired, causing us to
crash instead of using the non-class lookup result.
This fixes PR28060.
llvm-svn: 272247
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
Summary:
OpenCL should support array with const value size length, those const
varibale in global and constant address space and variable in constant
address space.
Fixed test case error.
Reviewers: Anastasia, yaxunl, bader
Subscribers: bader, cfe-commits
Differential Revision: http://reviews.llvm.org/D20090
llvm-svn: 271978
Summary:
OpenCL should support array with const value size length, those const varibale in global and constant address space and variable in constant address space.
Reviewers: Anastasia, yaxunl, bader
Subscribers: bader, cfe-commits
Differential Revision: http://reviews.llvm.org/D20090
llvm-svn: 271971
Instead of setting DeclSpec's range end to point to the next token
after the DeclSpec, we use getLocForEndOfToken to insert fix-it after a type
name.
Before this fix, fix-it will change
^(NSView view) to ^(*NSView view)
This commit correctly updates the source to ^(NSView* view).
rdar://21042144
Differential Revision: http://reviews.llvm.org/D20844
llvm-svn: 271448
Summary:
This patch fix the scoping of enum literal. They were not resolving
to the right type.
It was not causing any problem as one is a copy of the other one.
The literal in the switch are resolving to Sema.h:5527
```
enum AccessResult {
AR_accessible,
AR_inaccessible,
AR_dependent,
AR_delayed
};
```
Instead of SemaAccess.cpp:27
```
/// A copy of Sema's enum without AR_delayed.
enum AccessResult {
AR_accessible,
AR_inaccessible,
AR_dependent
};
```
This issue was found by a new clang-tidy check (still on-going).
Reviewers: rsmith, aaron.ballman
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D20773
llvm-svn: 271431
It's possible to have multiple local ObjCLifetime qualifiers. When there is
a conflict, we can't stop after we reach a type that is directly qualified.
We need to keep pulling sugar off and removing the ObjCLifetime qualifers.
rdar://25804796
Differential Revision: http://reviews.llvm.org/D20843
llvm-svn: 271409
Wilson.
An unqualified lookup for in base classes may cause stack overflow if
the base class is a specialization of current class.
Patch by Will Wilson.
llvm-svn: 271251
Summary:
Target regions require globals to be captured. This patch fixes a bug exposed when that happens in a template function.
Reviewers: hfinkel, arpith-jacob, kkwli0, carlo.bertolli, ABataev
Subscribers: guansong, ABataev, cfe-commits, caomhin, fraggamuffin
Differential Revision: http://reviews.llvm.org/D18110
llvm-svn: 271001
pretty stack trace entries for all cases where we instantiate the definition of
something, and include the fully-qualified name with template arguments in the
name of the instantiated entity.
llvm-svn: 270904
Also make explicit instantiation decls not apply to nested classes when
targeting MSVC. That dll attributes are not inherited by inner classes
might be the explanation for MSVC's behaviour here.
llvm-svn: 270897
Summary:
The patch contains the parsing and sema support for the `from` clause.
Patch based on the original post by Kelvin Li.
Reviewers: hfinkel, carlo.bertolli, kkwli0, arpith-jacob, ABataev
Subscribers: caomhin, cfe-commits
Differential Revision: http://reviews.llvm.org/D18488
llvm-svn: 270882
Summary:
The patch contains the parsing and sema support for the `to` clause.
Patch based on the original post by Kelvin Li.
Reviewers: carlo.bertolli, hfinkel, kkwli0, arpith-jacob, ABataev
Subscribers: caomhin, cfe-commits
Differential Revision: http://reviews.llvm.org/D18597
llvm-svn: 270880
Summary:
This patch is to add parsing and sema support for `target update` directive. Support for the `to` and `from` clauses will be added by a different patch. This patch also adds support for other clauses that are already implemented upstream and apply to `target update`, e.g. `device` and `if`.
This patch is based on the original post by Kelvin Li.
Reviewers: hfinkel, carlo.bertolli, kkwli0, arpith-jacob, ABataev
Subscribers: caomhin, cfe-commits
Differential Revision: http://reviews.llvm.org/D15944
llvm-svn: 270878
It is only a crash if the compiler optimize for this!=nullptr because
LocalInstantiationScope::getPartiallySubstitutedPack checks if 'this' is null
(This is crashing when clang is compiled with GCC6)
Differential Revision: http://reviews.llvm.org/D20511
llvm-svn: 270845
This implements support for MS-specific __unaligned qualifier in functions and
makes the following test case both compile and mangle correctly:
struct S {
void f() __unaligned;
};
void S::f() __unaligned {
}
Differential Revision: http://reviews.llvm.org/D20437
llvm-svn: 270834
objective-c properties.
This fixes an assert in CodeGen that fires when the getter and setter
functions for an objective-c property of type _Atomic(_Bool) are
synthesized.
rdar://problem/26322972
Differential Revision: http://reviews.llvm.org/D20407
llvm-svn: 270808
This matches what MSVC does, and should make compiles faster by avoiding to
unnecessarily emit a lot of code.
Differential Revision: http://reviews.llvm.org/D20608
llvm-svn: 270748
If we have some function with dllimport attribute and then we have the function
definition in the same module but without dllimport attribute we should add
dllexport attribute to this function definition.
The same should be done for variables.
Example:
struct __declspec(dllimport) C3 {
~C3();
};
C3::~C3() {;} // we should export this definition.
Patch by Andrew V. Tischenko
Differential revision: http://reviews.llvm.org/D18953
llvm-svn: 270686
Revision r211132 was supposed to disable -Warc-repeated-use-of-weak for
Objective-C properties marked with the IBOutlet attribute. Those properties
are supposed to be weak but they are only accessed from the main thread
so there is no risk of asynchronous updates setting them to nil. That
combination makes -Warc-repeated-use-of-weak very noisy. The previous
change only handled one kind of access to weak IBOutlet properties.
Instead of trying to add checks for all the different kinds of property
accesses, this patch removes the previous special case check and adds a
check at the point where the diagnostic is reported. rdar://21366461
llvm-svn: 270665
Summary:
In dependent contexts where we know a type name is required, such as a
new expression, we can recover by forming a DependentNameType.
This generalizes our existing compatibility hack for default arguments
for template type parameters.
Works towards parsing atlctrlw.h, which is PR26748.
Reviewers: avt77, rsmith
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D20500
llvm-svn: 270615
In case of template instantiations query the template instantiation pattern,
which had actually '=default'.
Fixes https://llvm.org/bugs/show_bug.cgi?id=27739
Patch reviewed by Richard Smith.
llvm-svn: 270553
Clang doesn't dllexport defaulted special member function defaulted
inside class but does it if they defaulted outside class. MSVC doesn't
make any distinction where they were defaulted. Also MSVC 2013 and 2015
export different set of members. MSVC2015 doesn't emit trivial defaulted
x-tors but does emit copy assign operator.
Differential revision: http://reviews.llvm.org/D20422
llvm-svn: 270535
MSVC now supports the __is_assignable type trait intrinsic,
to enable easier and more efficient implementation of the
Standard Library's is_assignable trait.
As of Visual Studio 2015 Update 3, the VC Standard Library
implementation uses the new intrinsic unconditionally.
The implementation is pretty straightforward due to the previously
existing is_nothrow_assignable and is_trivially_assignable.
We handle __is_assignable via the same code as the other two except
that we skip the extra checks for nothrow or triviality.
Patch by Dave Bartolomeo!
Differential Revision: http://reviews.llvm.org/D20492
llvm-svn: 270458
The layout_version attribute is pretty straightforward: use the layout
rules from version XYZ of MSVC when used like
struct __declspec(layout_version(XYZ)) S {};
The empty_bases attribute is more interesting. It tries to get the C++
empty base optimization to fire more often by tweaking the MSVC ABI
rules in subtle ways:
1. Disable the leading and trailing zero-sized object flags if a class
is marked __declspec(empty_bases) and is empty.
This means that given:
struct __declspec(empty_bases) A {};
struct __declspec(empty_bases) B {};
struct C : A, B {};
'C' will have size 1 and nvsize 0 despite not being annotated
__declspec(empty_bases).
2. When laying out virtual or non-virtual bases, disable the injection
of padding between classes if the most derived class is marked
__declspec(empty_bases).
This means that given:
struct A {};
struct B {};
struct __declspec(empty_bases) C : A, B {};
'C' will have size 1 and nvsize 0.
3. When calculating the offset of a non-virtual base, choose offset zero
if the most derived class is marked __declspec(empty_bases) and the
base is empty _and_ has an nvsize of 0.
Because of the ABI rules, this does not mean that empty bases
reliably get placed at offset 0!
For example:
struct A {};
struct B {};
struct __declspec(empty_bases) C : A, B { virtual ~C(); };
'C' will be pointer sized to account for the vfptr at offset 0.
'A' and 'B' will _not_ be at offset 0 despite being empty!
Instead, they will be located right after the vfptr.
This occurs due to the interaction betweeen non-virtual base layout
and virtual function pointer injection: injection occurs after the
nv-bases and shifts them down by the size of a pointer.
llvm-svn: 270457
OpenCL builtin functions to_{global|local|private} accepts argument of pointer type to arbitrary pointee type, and return a pointer to the same pointee type in different addr space, i.e.
global gentype *to_global(gentype *p);
It is not desirable to declare it as
global void *to_global(void *);
in opencl header file since it misses diagnostics.
This patch implements these builtin functions as Clang builtin functions. In the builtin def file they are defined to have signature void*(void*). When handling call expressions, their declarations are re-written to have correct parameter type and return type corresponding to the call argument.
In codegen call to addr void *to_addr(void*) is generated with addrcasts or bitcasts to facilitate implementation in builtin library.
Differential Revision: http://reviews.llvm.org/D19932
llvm-svn: 270261
According to Cuda Programming guide (v7.5, E2.3.1):
> __device__, __constant__ and __shared__ variables defined in namespace
> scope, that are of class type, cannot have a non-empty constructor or a
> non-empty destructor.
Clang already deals with device-side constructors (see D15305).
This patch enforces similar rules for destructors.
Differential Revision: http://reviews.llvm.org/D20140
llvm-svn: 270108
This reversal is being done with r267453's author's (i.e. Richard Smith's) permission.
This fixes https://llvm.org/bugs/show_bug.cgi?id=27601
Also, per Richard's request the examples from the bug report have been added to our test suite.
llvm-svn: 270016
an identifier table lookup, *and* copy the LangOptions (including various
std::vector<std::string>s). Twice. We call this function once each time we start
parsing a declaration specifier sequence, and once for each call to Sema::Diag.
This reduces the compile time for a sample .c file from the linux kernel by 20%.
llvm-svn: 270009
instance method.
When diagnosing unimplemented class property, make sure we emit
a warning when we only see an instance method with the right selector.
Also warn when we only see a class method for an instance property.
rdar://26141719
llvm-svn: 269968
I couldn't find any documentation that this form existed either. Nor is there documentation for one of the remaining two forms, but there is a testcase that uses it.
llvm-svn: 269879
For better performance and to unify code with offloading part we pass
scalar firstprivate values by value, instead of by reference. It will
remove some extra copying operations.
llvm-svn: 269751
Add supported OpenCL extensions to target info. It serves as default values to save the users of the burden setting each supported extensions and optional core features in command line.
Re-commit after fixing build error due to missing override attribute.
Differential Revision: http://reviews.llvm.org/D19484
llvm-svn: 269670
Revert r269431 due to build failure caused by warning msg:
llvm/tools/clang/lib/Basic/Targets.cpp:2090:9: error: 'setSupportedOpenCLOpts' overrides a member function but is not marked 'override' [-Werror,-Winconsistent-missing-override]
void setSupportedOpenCLOpts() {
llvm-svn: 269435
Add supported OpenCL extensions to target info. It serves as default values to save the users of the burden setting each supported extensions and optional core features in command line.
Differential Revision: http://reviews.llvm.org/D19484
llvm-svn: 269431
Clang creates implicit move constructor/assign operator in all cases if
there is std=c++11. But MSVC supports such generation starting from
version 1900 only. As result we have some binary incompatibility.
Differential Revision: http://reviews.llvm.org/D19156
Patch by Andrew V. Tischenko
llvm-svn: 269400
a base class via a using-declaration. If a class has a using-declaration
declaring either a constructor or an assignment operator, eagerly declare its
special members in case they need to displace a shadow declaration from a
using-declaration.
llvm-svn: 269398
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
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
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
Summary:
This only warns on casts of the address of a function defined in the
current TU. In this case, the fix is likely to be local and the warning
useful.
Here are some things we could experiment with in the future:
- Fire on declarations as well as definitions
- Limit the warning to non-void function prototypes
- Limit the warning to mismatches of caller and callee cleanup CCs
This warning is currently off by default while we study its usefulness.
Reviewers: thakis, rtrieu
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D17348
llvm-svn: 269116
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
Allow only empty constructors for local __shared__ variables in a way
identical to restrictions imposed on dynamic initializers for global
variables on device.
Differential Revision: http://reviews.llvm.org/D20039
llvm-svn: 268982
According to CUDA programming guide (v7.5):
> E.2.9.4: Within the body of a device or global function, only
> shared variables may be declared with static storage class.
Differential Revision: http://reviews.llvm.org/D20034
llvm-svn: 268962
Support OpenMP version 4.5 syntax for #pragma omp declare target.
Syntax:
#pragma omp declare target (extended-list) new-line
or
#pragma omp declare target clause[ [,] clause ... ] new-line
Where clause is one of the following:
to(extended-list)
link(list)
Differential Revision: http://reviews.llvm.org/D20011
llvm-svn: 268925
This patch corresponds to reviews:
http://reviews.llvm.org/D15120http://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
If the address of a field is taken as a pointer to member, we should
not warn that the field is not used.
Normaly, yse of fields are done from MemberExpr, but in case of pointer to
member, it is in a DeclRefExpr
Differential Revision: http://reviews.llvm.org/D20054
llvm-svn: 268895
When inferring availability attributes for tvos, watchos from ios, we
use the same source location and set the implicit bit to true.
So when emitting diagnostics on inferred attributes, we have a source
location.
rdar://25893544
llvm-svn: 268793
Sometimes, the declaration we found has inherited availability
attributes, attaching the note to it does not tell us where the
availability attributes are in the source.
Go through the redecl chain to find the declaration with actual
availability attributes.
rdar://25221771
llvm-svn: 268786
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
* an unscoped enumerator whose enumeration is a class member is itself a class
member, so can only be the subject of a class-scope using-declaration.
* a scoped enumerator cannot be the subject of a class-scope using-declaration.
llvm-svn: 268594
declared before it is used. Because we don't use normal name lookup to find
these, the normal code to filter out non-visible names from name lookup results
does not apply.
llvm-svn: 268585
BuildBlockForLambdaConversion.
Previously, clang would build an incorrect AST for the following code:
id test() {
return @{@"a": [](){}, @"b": [](){}};
}
ReturnStmt 0x10d080448
`-ExprWithCleanups 0x10d080428
|-cleanup Block 0x10d0801f0 // points to the second BlockDecl
...
-BlockDecl 0x10d07f150 // First block
...
-BlockDecl 0x10d0801f0 // Second block
...
`-ExprWithCleanups 0x10d0801d0
|-cleanup Block 0x10d07f150 // points to the first BlockDecl
To fix the bug, this commit enters a new evaluation context to reset
ExprNeedsCleanups before each block is parsed.
rdar://problem/16879958
Differential Revision: http://reviews.llvm.org/D18815
llvm-svn: 268527
In r268085 "[MS] Make #pragma pack use PragmaStack<> class." there was an
uninitialized variable 'Alignment', which caused the following failure:
http://lab.llvm.org:8011/builders/sanitizer-ppc64be-linux/builds/1758
Zero-initialize the variable to fix this failure.
llvm-svn: 268129
a selector, the entry should be complete, containing everything introduced by
that module and all modules it imports.
Before writing out the method pool of a module, we sync up the out of date
selectors by pulling in methods for the selectors, from all modules it imports.
In ReadMethodPool, after pulling in the method pool entry for module A, this
lets us skip the modules that module A imports.
rdar://problem/25900131
llvm-svn: 268091
Make implementation of #pragma pack consistent with other "stack" pragmas.
Use PragmaStack<> class instead of old representation of internal stack.
Don't change compiler's behavior.
TODO:
1. Introduce diagnostics on popping named slots from pragma stacks.
Reviewer: rnk
Differential revision: http://reviews.llvm.org/D19727
llvm-svn: 268085
Fix crash in BuildCXXDefaultInitExpr when member of template class has
same name as the class itself.
Based on patch by Raphael "Teemperor" Isemann!
Differential Revision: http://reviews.llvm.org/D19721
llvm-svn: 268082
The 'nodebug' attribute had hand-coded constraints; replace those with
a Subjects line in Attr.td.
Also add a missing test to verify the attribute is okay on an
Objective-C method.
Differential Revision: http://reviews.llvm.org/D19689
llvm-svn: 268065
Slightly updated version, double-checked build and tests.
Improve implementation of MS pragmas that use stack + compatibility fixes.
This patch:
1. Changes implementation of #pragma vtordisp to use PragmaStack class
that other stack pragmas use;
2. Fixes "#pragma vtordisp()" behavior - it shouldn't affect the stack;
3. Supports "save-restore" of pragma stacks on enter / exit a C++ method
body, as MSVC does.
TODO:
1. Change implementation of #pragma pack to use the same approach;
2. Introduce diagnostics on popping named stack slots, as MSVC does.
Reviewers:
rnk, thakis
Differential revision: http://reviews.llvm.org/D19361
llvm-svn: 268029
if we are parsing a template specialization.
This commit makes changes to clear the TemplateParamScope bit and set
the TemplateParamParent field of the current scope to null if a template
specialization is being parsed.
Before this commit, Sema::ActOnStartOfLambdaDefinition would check
whether the parent template scope had any decls to determine whether
or not a template specialization was being parsed. This wasn't correct
since it couldn't distinguish between a real template specialization and
a template defintion with an unnamed template parameter (only template
parameters with names are added to the scope's decl list). To fix the
bug, this commit changes the code to check the pointer to the parent
template scope rather than the decl list.
rdar://problem/23440346
Differential Revision: http://reviews.llvm.org/D19175
llvm-svn: 267975
Usually these parameters are used solely to initialize the field in the
initializer list, and there is no real shadowing confusion.
There is a new warning under -Wshadow called
-Wshadow-field-in-constructor-modified. It attempts to find
modifications of such constructor parameters that probably intended to
modify the field.
It has some false negatives, though, so there is another warning group,
-Wshadow-field-in-constructor, which always warns on this special case.
For users who just want the old behavior and don't care about these fine
grained groups, we have a new warning group called -Wshadow-all that
activates everything.
Fixes PR16088.
Reviewers: rsmith
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D18271
llvm-svn: 267957
with a generic lambda.
This patch fixes Sema::InstantiateVariableInitializer to switch to the
context of the variable before instantiating its initializer, which is
necessary to set the correct type for VarTemplateSpecializationDecl.
This is the first part of the patch that was reviewed here:
http://reviews.llvm.org/D19175
rdar://problem/23440346
llvm-svn: 267956
OpenMP 4.5 defines 'taskloop simd' directive, which is combined
directive for 'taskloop' and 'simd' directives. Patch adds initial
codegen support for this directive and its 2 basic clauses 'safelen' and
'simdlen'.
llvm-svn: 267872
It makes compiler-rt tests fail if the gold plugin is enabled.
Revert "Rework interface for bitset-using features to use a notion of LTO visibility."
Revert "Driver: only produce CFI -fvisibility= error when compiling."
Revert "clang/test/CodeGenCXX/cfi-blacklist.cpp: Exclude ms targets. They would be non-cfi."
llvm-svn: 267871
Rework implementation of several MS pragmas that use internal stack:
vtordisp, {bss|code|const|data}_seg.
This patch:
1. Makes #pragma vtordisp use PragmaStack class as *_seg pragmas do;
2. Fixes "#pragma vtordisp()" behavior: it shouldn't affect stack;
3. Saves/restores the stacks on enter/exit a C++ method body.
llvm-svn: 267866
Summary:
Implement codegen for the map clause. All the new list items in 4.5 specification are supported.
Fix bug in the generation of array sections that was exposed by some of the map clause tests: for pointer types the offsets have to be calculated from the pointee not the pointer.
Reviewers: hfinkel, kkwli0, carlo.bertolli, arpith-jacob, ABataev
Subscribers: ABataev, cfe-commits, caomhin, fraggamuffin
Differential Revision: http://reviews.llvm.org/D16749
llvm-svn: 267808
Bitsets, and the compiler features they rely on (vtable opt, CFI),
only have visibility within the LTO'd part of the linkage unit. Therefore,
only enable these features for classes with hidden LTO visibility. This
notion is based on object file visibility or (on Windows)
dllimport/dllexport attributes.
We provide the [[clang::lto_visibility_public]] attribute to override the
compiler's LTO visibility inference in cases where the class is defined
in the non-LTO'd part of the linkage unit, or where the ABI supports
calling classes derived from abstract base classes with hidden visibility
in other linkage units (e.g. COM on Windows).
If the cross-DSO CFI mode is enabled, bitset checks are emitted even for
classes with public LTO visibility, as that mode uses a separate mechanism
to cause bitsets to be exported.
This mechanism replaces the whole-program-vtables blacklist, so remove the
-fwhole-program-vtables-blacklist flag.
Because __declspec(uuid()) now implies [[clang::lto_visibility_public]], the
support for the special attr:uuid blacklist entry is removed.
Differential Revision: http://reviews.llvm.org/D18635
llvm-svn: 267784
The Decl::isUsed has a value for every decl. In non-module builds it is very
difficult (but possible) to break this invariant but when we walk up the redecl
chain we find the neccessary information.
When deserializing the decls from a module it is much more difficult to update
correctly this invariant. The patch centralizes the information whether a decl
is used in the canonical decl marking the entire entity as being used.
Fixes https://llvm.org/bugs/show_bug.cgi?id=27401
Patch by Cristina Cristescu and me.
Thanks to Richard Smith who helped to debug and understand the issue!
Reviewed by Richard Smith.
llvm-svn: 267691
Summary:
This patch adds logic to save the components of mappable expressions in the clause that uses it, so that they don't have to be recomputed during codegen. Given that the mappable components are (will be) used in several clauses a new geneneric implementation `OMPMappableExprListClause` is used that extends the existing `OMPVarListClause`.
This patch does not add new tests. The goal is to preserve the existing functionality while storing more info in the clauses.
Reviewers: hfinkel, carlo.bertolli, arpith-jacob, kkwli0, ABataev
Subscribers: cfe-commits, caomhin
Differential Revision: http://reviews.llvm.org/D19382
llvm-svn: 267560
The taskloop construct specifies that the iterations of one or more associated loops will be executed in parallel using OpenMP tasks. The iterations are distributed across tasks created by the construct and scheduled to be executed.
The next code will be generated for the taskloop directive:
#pragma omp taskloop num_tasks(N) lastprivate(j)
for( i=0; i<N*GRAIN*STRIDE-1; i+=STRIDE ) {
int th = omp_get_thread_num();
#pragma omp atomic
counter++;
#pragma omp atomic
th_counter[th]++;
j = i;
}
Generated code:
task = __kmpc_omp_task_alloc(NULL,gtid,1,sizeof(struct
task),sizeof(struct shar),&task_entry);
psh = task->shareds;
psh->pth_counter = &th_counter;
psh->pcounter = &counter;
psh->pj = &j;
task->lb = 0;
task->ub = N*GRAIN*STRIDE-2;
task->st = STRIDE;
__kmpc_taskloop(
NULL, // location
gtid, // gtid
task, // task structure
1, // if clause value
&task->lb, // lower bound
&task->ub, // upper bound
STRIDE, // loop increment
0, // 1 if nogroup specified
2, // schedule type: 0-none, 1-grainsize, 2-num_tasks
N, // schedule value (ignored for type 0)
(void*)&__task_dup_entry // tasks duplication routine
);
llvm-svn: 267395
Remove the floating point to bool conversion warnings. Some of these
conversions will be caught by -Wliteral-conversion and -Wfloat-conversion
llvm-svn: 267234
If loop control variable for simd-based directives is explicitly marked
as linear/lastprivate in clauses, codegen for such construct would
crash. Patch fixes this problem.
llvm-svn: 267101
Restructure the implict floating point to integer conversions so that
interesting sub-groups are under different flags. Breakdown of warnings:
No warning:
Exact conversions from floating point to integer:
int x = 10.0;
int x = 1e10;
-Wliteral-conversion - Floating point literal to integer with rounding:
int x = 5.5;
int x = -3.4;
-Wfloat-conversion - All conversions not covered by the above two:
int x = GetFloat();
int x = 5.5 + 3.5;
-Wfloat-zero-conversion - The expression converted has a non-zero floating
point value that gets converted to a zero integer value, excluded the cases
falling under -Wliteral-conversion. Subset of -Wfloat-conversion.
int x = 1.0 / 2.0;
-Wfloat-overflow-conversion - The floating point value is outside the range
of the integer type, exluding cases from -Wliteral conversion. Subset of
-Wfloat-conversion.
char x = 500;
char x = -1000;
-Wfloat-bool-conversion - Any conversion of a floating point type to bool.
Subset of -Wfloat-conversion.
if (GetFloat()) {}
bool x = 5.0;
-Wfloat-bool-constant-conversion - Conversion of a compile time evaluatable
floating point value to bool. Subset of -Wfloat-bool-conversion.
bool x = 1.0;
bool x = 4.0 / 20.0;
Also add EvaluateAsFloat to Sema, which is similar to EvaluateAsInt, but for
floating point values.
llvm-svn: 267054
If the untied clause is present on a task construct, any thread in the
team can resume the task region after a suspension. Patch adds proper
codegen for untied tasks.
llvm-svn: 266853
If the untied clause is present on a task construct, any thread in the
team can resume the task region after a suspension. Patch adds proper
codegen for untied tasks.
llvm-svn: 266754
If the untied clause is present on a task construct, any thread in the team can resume the task region after a suspension. Patch adds proper codegen for untied tasks.
llvm-svn: 266722
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
return type.
Emit a warning instead of crashing in IR generation.
rdar://22762981
Differential Revision: http://reviews.llvm.org/D18567
llvm-svn: 266648
template<class T> void f(T) = delete;
template<> void f(int); // OK.
f(3); // OK
Implementation strategy:
When an explicit specialization of a function template, a member function template or a member function of a class template is declared, clang first implicitly instantiates the declaration of a specialization from the templated-entity being explicitly specialized (since their signatures must be the same) and then links the explicit specialization being declared as a redeclaration of the aforementioned specialization.
The problem was that when clang 'implicitly instantiates' the initial specialization, it marks the corresponding FunctionDecl as deleted if the corresponding templated-entity was deleted, rather than waiting to see whether the explicit specialization being declared provides a non-deleted body. (The eager marking of delete has advantages during overload resolution I suppose, where we don't have to try and instantiate a definition of the function to see if it is deleted).
The present fix entails recognizing that when clang knows that an explicit specialization is being declared (for whichever templated-entity), the prior implicit instantiation should not inherit the 'deleted' status, and so we reset it to false.
I suppose an alternative fix (amongst others) could consider creating a new context (ExplicitSpecializationDeclarationSubstitution or some such) that is checked during template-argument-deduction and final substitution, and avoid inheriting the deleted status during declaration substitution. But while conceptually cleaner, that would be a slightly more involved change (as could be some of the other alternatives: such as avoid tagging implicit specializations as deleted, and check their primary templates for the deleted status where needed), and so I chose a different path. Hopefully it'll prove to not be a bad choice.
llvm-svn: 266561
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
This patch implements __unaligned as a type qualifier; before that, it was
modeled as an attribute. Proper mangling of __unaligned is implemented as well.
Some OpenCL code/tests are tangenially affected, as they relied on existing
number and sizes of type qualifiers.
Differential Revision: http://reviews.llvm.org/D18596
llvm-svn: 266415
The example below should work identically with and without compiler native
wchar_t support.
void foo(wchar_t * t = L"");
Differential Revision: http://reviews.llvm.org/D19056
llvm-svn: 266287
r265877 tries to put methods that are deprecated or unavailable to the
front of the global pool to emit diagnostics, but it breaks some of
our existing codes that depend on choosing a certain method for id
lookup.
This commit orders the methods with the same declaration with respect
to the availability, but do not order methods with different declaration.
rdar://25707511
llvm-svn: 266264
Under certain conditions clang currently fails to properly diagnostic ObjectC
parameter list when type args and protocols are mixed in the same list. This
happens when the first item in the parameter list is a (1) protocol, (2)
unknown type or (3) a list of protocols/unknown types up to the first type
argument. Fix the problem to report the proper error, example:
NSArray<M, NSValue *, NSURL, NSArray <id <M>>> *foo = @[@"a"];
NSNumber *bar = foo[0];
NSLog(@"%@", bar);
$ clang ...
x.m:7:13: error: angle brackets contain both a type ('NSValue') and a protocol ('M')
NSArray<M, NSValue *, NSURL, NSArray <id <M>>> *foo = @[@"a"];
~ ^
Differential Revision: http://reviews.llvm.org/D18997
rdar://problem/22204367
llvm-svn: 266245
Although all the registers are actually 32-bits, I think we have to assume the
high 32-bits could be RES0 (the ARM ARM is unclear). If so, reading as a 32-bit
register can require extra zero extension operations.
llvm-svn: 266212
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
Putting OpenCLImageTypes.def to clangAST library violates layering requirement: "It's not OK for a Basic/ header to include an AST/ header".
This fixes the modules build.
Differential revision: http://reviews.llvm.org/D18954
Reviewers: Richard Smith, Vassil Vassilev.
llvm-svn: 266180
The linear clause declares one or more list items to be private to a SIMD lane and to have a linear relationship with respect to the iteration space of a loop.
'linear' '(' <linear-list> [ ':' <linear-step> ] ')'
When a linear-step expression is specified in a linear clause it must be
either a constant integer expression or an integer-typed parameter that is specified in a uniform clause on the directive.
The special this pointer can be used as if was one of the arguments to the function in any of the linear, aligned, or uniform clauses.
llvm-svn: 266056
The aligned clause declares that the object to which each list item points is aligned to the number of bytes expressed in the optional parameter of the aligned clause.
'aligned' '(' <argument-list> [ ':' <alignment> ] ')'
The optional parameter of the aligned clause, alignment, must be a constant positive integer expression. If no optional parameter is specified, implementation-defined default alignments for SIMD instructions on the target platforms are assumed.
The special this pointer can be used as if was one of the arguments to the function in any of the linear, aligned, or uniform clauses.
llvm-svn: 266052
OpenMP 4.0 defines clause 'uniform' in 'declare simd' directive:
'uniform' '(' <argument-list> ')'
The uniform clause declares one or more arguments to have an invariant value for all concurrent invocations of the function in the execution of a single SIMD loop.
The special this pointer can be used as if was one of the arguments to the function in any of the linear, aligned, or uniform clauses.
llvm-svn: 266041
This patch add support for GCC attribute((ifunc("resolver"))) for
targets that use ELF as object file format. In general ifunc is a
special kind of function alias with type @gnu_indirect_function. LLVM
patch http://reviews.llvm.org/D15525
Differential Revision: http://reviews.llvm.org/D15524
llvm-svn: 265917
To make kindof lookup work, we need to insert methods with different
context into the global pool, even though they have the same siganture.
Since diagnosis of availability is performed on the best candidate,
which is often the first candidate from the global pool, we prioritize
the methods that are unavaible or deprecated to the head of the list.
Since we now have more methods in the global pool, we need to watch
out for performance impact.
rdar://25635831
llvm-svn: 265877
Summary: A program shall not declare an explicit instantiation (14.8.2), an explicit specialization (14.8.3), or a partial specialization of a concept definition.
Reviewers: rsmith, hubert.reinterpretcast, faisalv, aaron.ballman
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D18221
llvm-svn: 265868
I. Current implementation of images is not conformant to spec in the following points:
1. It makes no distinction with respect to access qualifiers and therefore allows to use images with different access type interchangeably. The following code would compile just fine:
void write_image(write_only image2d_t img);
kernel void foo(read_only image2d_t img) { write_image(img); } // Accepted code
which is disallowed according to s6.13.14.
2. It discards access qualifier on generated code, which leads to generated code for the above example:
call void @write_image(%opencl.image2d_t* %img);
In OpenCL2.0 however we can have different calls into write_image with read_only and wite_only images.
Also generally following compiler steps have no easy way to take different path depending on the image access: linking to the right implementation of image types, performing IR opts and backend codegen differently.
3. Image types are language keywords and can't be redeclared s6.1.9, which can happen currently as they are just typedef names.
4. Default access qualifier read_only is to be added if not provided explicitly.
II. This patch corrects the above points as follows:
1. All images are encapsulated into a separate .def file that is inserted in different points where image handling is required. This avoid a lot of code repetition as all images are handled the same way in the code with no distinction of their exact type.
2. The Cartesian product of image types and image access qualifiers is added to the builtin types. This simplifies a lot handling of access type mismatch as no operations are allowed by default on distinct Builtin types. Also spec intended access qualifier as special type qualifier that are combined with an image type to form a distinct type (see statement above - images can't be created w/o access qualifiers).
3. Improves testing of images in Clang.
Author: Anastasia Stulova
Reviewers: bader, mgrang.
Subscribers: pxli168, pekka.jaaskelainen, yaxunl.
Differential Revision: http://reviews.llvm.org/D17821
llvm-svn: 265783
CodeGen-level implementation. Instead of adding an attribute to clang's
FunctionDecl, add the IR attribute directly. This means a module built with
this flag is now compatible with code built without it and vice versa.
This change also results in the 'noalias' attribute no longer being added to
calls to operator new in the IR; it's now only added to the declaration. It
also fixes a bug where we failed to add the attribute to the 'nothrow' versions
(because we didn't implicitly declare them, there was no good time to inject a
fake attribute).
llvm-svn: 265728
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
construct.
OpenMP 4.0 defines '#pragma omp declare simd' construct that may have
associated 'simdlen' clause with constant positive expression as an
argument:
simdlen(<const_expr>)
Patch adds parsin and semantic analysis for simdlen clause.
llvm-svn: 265668
Add parsing, sema analysis for 'declare target' construct for OpenMP 4.0
(4.5 support will be added in separate patch).
The declare target directive specifies that variables, functions (C, C++
and Fortran), and subroutines (Fortran) are mapped to a device. The declare
target directive is a declarative directive. In Clang declare target is
implemented as implicit attribute for the declaration.
The syntax of the declare target directive is as follows:
#pragma omp declare target
declarations-definition-seq
#pragma omp end declare target
Based on patch from Michael Wong http://reviews.llvm.org/D15321
llvm-svn: 265530
This is a fix for https://llvm.org/bugs/show_bug.cgi?id=25561 which was a
crash on invalid. Change the handling of invalid decls to have a catch-all
case to prevent unexpecting decls from triggering an assertion.
llvm-svn: 265467
The objc_runtime_visible attribute deals with an odd corner case where
a particular Objective-C class is known to the Objective-C runtime
(and, therefore, accessible by name) but its symbol has been hidden
for some reason. For such classes, teach CodeGen to use
objc_lookUpClass to retrieve the Class object, rather than referencing
the class symbol directly.
Classes annotated with objc_runtime_visible have two major limitations
that fall out from places where Objective-C metadata needs to refer to
the class (or metaclass) symbol directly:
* One cannot implement a subclass of an objc_runtime_visible class.
* One cannot implement a category on an objc_runtime_visible class.
Implements rdar://problem/25494092.
llvm-svn: 265201
directives.
OpenMP 4.5 allows privatization of non-static data members in non-static
member functions. Patch allows to use and implicit privatization of data
members used as counters in loop-based directives.
llvm-svn: 265121
It is not widely used and removed from OpenCL v2.1.
This change modifies Clang to parse the attribute for OpenCL
but ignores it afterwards.
Patch by Liu Yaxun (Sam)!
Differential Revision: http://reviews.llvm.org/D17861
llvm-svn: 265006
This warning sometimes will infinitely recurse on CXXRecordDecl's from
ill-formed recursive classes that have fields of themselves. Skip processing
these classes to prevent this from happening.
Fixes https://llvm.org/bugs/show_bug.cgi?id=27142
llvm-svn: 264991
In some cases, when we encounter a direct function call with an
incorrect number of arguments, we'll emit a diagnostic, and pretend that
the call to the function was valid. For example, in C:
int foo();
int a = foo(1);
Prior to this patch, we'd get an ICE if foo had an enable_if attribute,
because CheckEnableIf assumes that the number of arguments it gets
passed is valid for the function it's passed. Now, we check that the
number of args looks valid prior to checking enable_if conditions.
This fix was not done inside of CheckEnableIf because the problem
presently can only occur in one caller of CheckEnableIf (ActOnCallExpr).
Additionally, checking inside of CheckEnableIf would make us emit
multiple diagnostics for the same error (one "enable_if failed", one
"you gave this function the wrong number of arguments"), which seems
worse than just complaining about the latter.
llvm-svn: 264975
Summary:
__atomic_load's allows it's first argument to be a pointer to a const type. However the second argument is an output parameter and must be a pointer to non-const.
This patch fixes the signature of __atomic_load generated by clang so that it respects the above requirements.
Reviewers: rsmith, majnemer
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D13420
llvm-svn: 264967
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
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
Initial parsing/sema/serialization/deserialization support for '#pragma
omp declare simd' directive.
The 'declare simd' construct can be applied to a function to enable the
creation of one or more versions that can process multiple arguments
using SIMD instructions from a single invocation from a SIMD loop.
If the function has any declarations, then the declare simd construct
for any declaration that has one must be equivalent to the one specified
for the definition. Otherwise, the result is unspecified.
This pragma can be applied many times to the same declaration.
Internally this pragma is represented as an attribute. But we need special processing for this pragma because it must be used before function declaration, this directive is applied to.
Differential Revision: http://reviews.llvm.org/D10599
llvm-svn: 264853
...as that is apparently what MSVC does. This is an updated version of r263738,
which had to be reverted in r263740 due to test failures. The original version
had erroneously emitted functions that are defined in class templates, too (see
the updated "Handle friend functions" code in EmitDeferredDecls,
lib/CodeGen/ModuleBuilder.cpp). (The updated tests needed to be split out into
their own dllexport-ms-friend.cpp because of the CHECK-NOTs which would have
interfered with subsequent CHECK-DAGs in dllexport.cpp.)
Differential Revision: http://reviews.llvm.org/D18430
llvm-svn: 264841
Summary:
1. Diag should be output if types are not the same.
2. Should compare using canonical type.
3. Refine the diag to be more clear.
Reviewers: yaxunl, Anastasia
Subscribers: MatsPetersson, pekka.jaaskelainen, cfe-commits
Differential Revision: http://reviews.llvm.org/D17955
llvm-svn: 264825
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
For better support of some specific GNU extensions some extra
transformation of AST nodes were introduced. These transformations are
very hard to handle. The code is improved in handling of these
extensions by using captured expressions construct.
llvm-svn: 264709
I broke this back in r264529 because I forgot to serialize the UuidAttr
member. Fix this by replacing the UuidAttr with a StringRef which is
properly serialized and deserialized.
llvm-svn: 264562
Keep a pointer to the UuidAttr that the CXXUuidofExpr corresponds to.
This makes translating from __uuidof to the underlying constant a lot
more straightforward.
llvm-svn: 264529
The prior diagnostic (err_template_arg_not_class_template) would state that the template argument to a template template parameter can only be a class template, when it can also be a template alias. The newly renamed diagnostic (err_template_arg_not_valid_template) mentions template aliases.
llvm-svn: 264522
Support the constexpr specifier on lambda expressions - and support its inference from the lambda call operator's body.
i.e.
auto L = [] () constexpr { return 5; };
static_assert(L() == 5); // OK
auto Implicit = [] (auto a) { return a; };
static_assert(Implicit(5) == 5);
We do not support evaluation of lambda's within constant expressions just yet.
Implementation Strategy:
- teach ParseLambdaExpressionAfterIntroducer to expect a constexpr specifier and mark the invented function call operator's declarator's decl-specifier with it; Have it emit fixits for multiple decl-specifiers (mutable or constexpr) in this location.
- for cases where constexpr is not explicitly specified, have buildLambdaExpr check whether the invented function call operator satisfies the requirements of a constexpr function, by calling CheckConstexprFunctionDecl/Body.
Much obliged to Richard Smith for his patience and his care, in ensuring the code is clang-worthy.
llvm-svn: 264513
use. In order for this to fire, the function needed to be a templated function
marked 'constexpr' and declared but not defined. This weird pattern appears in
libstdc++'s alloc_traits.h.
llvm-svn: 264471
non-deterministic diagnostics (and non-deterministic PCH files). Check these
when building a module rather than serializing it; it's not reasonable for a
module's use to be satisfied by a definition in the user of the module.
llvm-svn: 264466
lambda-expression. We don't actually instantiate the closure type / operator()
in the template in order to produce the closure type / operator() in the
instantiation, so this isn't caught by the normal path.
llvm-svn: 264184
Before this commit, we assert failure in ImplicitCastExpr
"unheralded conversion to bool". This commit fixes the assertion by using
the correct cast type when the fixed type is boolean.
This commit also fixes the behavior for Microsoft mode as well, since
Obj-C and Microsoft mode share the same code path.
rdar://24999533
llvm-svn: 264167
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
While we correctly assigned an inheritance model for the source of a
member pointer upcast, we did not do so for the destination.
This fixes PR27030.
llvm-svn: 264065
IsExact shouldn't be set to true in WeakObjectProfileTy::getBaseInfo
when the receiver is a class because having a class as the receiver
doesn't guarantee that the Base is exact.
This is a follow-up to r263818.
rdar://problem/25208167
llvm-svn: 264025
This commit adds a named argument to AvailabilityAttr, while r263652 adds an
optional string argument to __attribute__((deprecated)).
This was commited in r263687 and reverted in 263752 due to misaligned
access.
rdar://20588929
llvm-svn: 263958
Implement lambda capture of *this by copy.
For e.g.:
struct A {
int d = 10;
auto foo() { return [*this] (auto a) mutable { d+=a; return d; }; }
};
auto L = A{}.foo(); // A{}'s lifetime is gone.
// Below is still ok, because *this was captured by value.
assert(L(10) == 20);
assert(L(100) == 120);
If the capture was implicit, or [this] (i.e. *this was captured by reference), this code would be otherwise undefined.
Implementation Strategy:
- amend the parser to accept *this in the lambda introducer
- add a new king of capture LCK_StarThis
- teach Sema::CheckCXXThisCapture to handle by copy captures of the
enclosing object (i.e. *this)
- when CheckCXXThisCapture does capture by copy, the corresponding
initializer expression for the closure's data member
direct-initializes it thus making a copy of '*this'.
- in codegen, when assigning to CXXThisValue, if *this was captured by
copy, make sure it points to the corresponding field member, and
not, unlike when captured by reference, what the field member points
to.
- mark feature as implemented in svn
Much gratitude to Richard Smith for his carefully illuminating reviews!
llvm-svn: 263921
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's type in type
deduction.
Differential Revision: http://reviews.llvm.org/D15591
llvm-svn: 263888
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
This patch implements the following aspects:
It extends sema to check that a variable is not reference in both a map clause and firstprivate or private. This is needed to ensure correct functioning at codegen level, apart from being useful for the user.
It implements firstprivate for target in codegen. The implementation applies to both host and nvptx devices.
It adds regression tests for codegen of firstprivate, host and device side when using the host as device, and nvptx side.
Please note that the regression test for nvptx codegen is missing VLAs. This is because VLAs currently require saving and restoring the stack which appears not to be a supported operation by nvptx backend.
It adds a check in sema regression tests for target map, firstprivate, and private clauses.
http://reviews.llvm.org/D18203
llvm-svn: 263837
The crash occurs in WeakObjectProfileTy::getBaseInfo when getBase() is
called on an ObjCPropertyRefExpr object whose receiver is an interface.
This commit fixes the crash by checking the type of the receiver and
setting IsExact to true if it is an interface.
rdar://problem/25208167
Differential Revision: http://reviews.llvm.org/D18268
llvm-svn: 263818
Summary: ...as that is apparently what MSVC does
Reviewers: rnk
Patch by Stephan Bergmann
Differential Revision: http://reviews.llvm.org/D15267
llvm-svn: 263738
OpenMP 4.5 allows privatization of non-static data members in non-static
member functions. This patch adds support of private data members in
'copyprivate' clauses.
llvm-svn: 263706
OpenMP 4.0 allows to define custom reduction operations using '#pragma
omp declare reduction' construct. Patch allows to use this custom
defined reduction operations in 'reduction' clauses.
llvm-svn: 263701
This commit adds a named argument to AvailabilityAttr, while r263652 adds an
optional string argument to __attribute__((deprecated)). This enables the
compiler to provide Fix-Its for deprecated declarations.
rdar://20588929
llvm-svn: 263687
Till now, preserve_mostcc/preserve_allcc calling convention attributes were only
available at the LLVM IR level. This patch adds attributes for
preserve_mostcc/preserve_allcc calling conventions to the C/C++ front-end.
The code was mostly written by Juergen Ributzka.
I just added support for the AArch64 target and tests.
Differential Revision: http://reviews.llvm.org/D18025
llvm-svn: 263647
The declaration of the destructor of an invalid class was not properly marked
as noexcept. As a result, the definition of the same destructor, which was
properly implicitly marked as noexcept, would not match the definition.
This would cause the definition CXXDestructorDecl to be matked as invalid
and omited from the AST.
Differential Revision: http://reviews.llvm.org/D17988
llvm-svn: 263639
The purpose of this patch is to keep the same functionality without using LookupResult's implicit copy ctor and assignment operator, because they cause warnings when -Wdeprecated is passed.
This patch is meant to help the following review: http://reviews.llvm.org/D18123.
The functionality is covered by the tests in my original commit (255890)
The test case in this patch was added to test a bug caught in the review of the first version of this fix.
Differential Revision: http://reviews.llvm.org/D18175
llvm-svn: 263630
r263299 added a fixit for the -Wformat-security warning, but that runs
into complications with our guideline that error recovery should be done
as-if the fixit had been applied. Putting the fixit on a note avoids that.
llvm-svn: 263584
This feature works outside of templates by forming a DeclRefExpr to a
FieldDecl instead of a MemberExpr, which requires a base object in
addition to the FieldDecl.
Previously, while building up the template AST before instantiation, we
formed a CXXDependentScopeMemberExpr, which always instantiates to a
MemberExpr. Now, in unevaluated contexts we form a
DependentScopeDeclRefExpr, which is a more flexible node that can
instantiate to either a MemberExpr or a DeclRefExpr depending on lookup
results.
Fixes PR26893.
llvm-svn: 263279
Given the following test case:
typedef struct {
const char *name;
id field;
} Test9;
extern void doSomething(Test9 arg);
void test9() {
Test9 foo2 = {0, 0};
doSomething(foo2);
}
With a release compiler, we don't emit any message and silently ignore the
variable "foo2". With an assert compiler, we get an assertion failure.
The root cause —————————————
Back in r140457 we gave InitListChecker a verification-only mode, and will use
CanUseDecl instead of DiagnoseUseOfDecl for verification-only mode.
These two functions handle unavailable issues differently:
In Sema::CanUseDecl, we say the decl is invalid when the Decl is unavailable and
the current context is available.
In Sema::DiagnoseUseOfDecl, we say the decl is usable by ignoring the return
code of DiagnoseAvailabilityOfDecl
So with an assert build, we will hit an assertion in diagnoseListInit
assert(DiagnoseInitList.HadError() &&
"Inconsistent init list check result.");
The fix -------------------
If we follow what is implemented in CanUseDecl and treat Decls with
unavailable issues as invalid, the variable decl of “foo2” will be marked as
invalid. Since unavailable checking is processed in delayed diagnostics
(r197627), we will silently ignore the diagnostics when we find out that
the variable decl is invalid.
We add a flag "TreatUnavailableAsInvalid" for the verification-only mode.
For overload resolution, we want to say decls with unavailable issues are
invalid; but for everything else, we should say they are valid and
emit diagnostics. Depending on the value of the flag, CanUseDecl
can return different values for unavailable issues.
rdar://23557300
Differential Revision: http://reviews.llvm.org/D15314
llvm-svn: 263149
Summary:
For PseudoObjectExpr, the DeclMatcher need to search only all the semantics
but also need to search pass OpaqueValueExpr for all potential uses for the
Decl.
Reviewers: thakis, rtrieu, rjmccall, doug.gregor
Subscribers: xazax.hun, rjmccall, doug.gregor, cfe-commits
Differential Revision: http://reviews.llvm.org/D17627
llvm-svn: 263087
Summary: In some cases it can be proved statically that multidimensional array section refer to contiguous storage and can therefore be allowed in a map clause. This patch adds support for those cases in SEMA.
Reviewers: hfinkel, carlo.bertolli, arpith-jacob, kkwli0, ABataev
Subscribers: cfe-commits, fraggamuffin, caomhin
Differential Revision: http://reviews.llvm.org/D17547
llvm-svn: 263019
Original patch by Stefan Bühler http://reviews.llvm.org/D12834
Difference between original and this one:
- fixed all comments in original code review
- added more tests, all new diagnostics now covered by tests
- moved abi_tag on re-declaration checks to Sema::mergeDeclAttributes
where they actually may work as designed
- clang-format + other stylistic changes
Mangle part will be sent for review as a separate patch.
Differential Revision: http://reviews.llvm.org/D17567
llvm-svn: 263015
Similar to the template cases in r262050, when a C++ method in an
unavailable struct/class calls unavailable API, don't diagnose an error.
I.e., this case was failing:
void foo() __attribute__((unavailable));
struct __attribute__((unavailable)) A {
void bar() { foo(); }
};
Since A is unavailable, A::bar is allowed to call foo. However, we were
emitting a diagnostic here. This commit checks up the context chain
from A::bar, in a manner inspired by SemaDeclAttr.cpp:isDeclUnavailable.
I expected to find other related issues but failed to trigger them:
- I wondered if DeclBase::getAvailability should check for
`TemplateDecl` instead of `FunctionTemplateDecl`, but I couldn't find
a way to trigger this. I left behind a few extra tests to make sure
we don't regress.
- I wondered if Sema::isFunctionConsideredUnavailable should be
symmetric, checking up the context chain of the callee (this commit
only checks up the context chain of the caller). However, I couldn't
think of a testcase that didn't require first referencing the
unavailable type; this, we already diagnose.
rdar://problem/25030656
llvm-svn: 262921
This is a follow-up to r261512, which made the 'strict' availability
attribute flag behave like 'unavailable'. However, that fix was
insufficient. The following case would (erroneously) error when the
deployment target was older than 10.9:
struct __attribute__((availability(macosx,strict,introduced=10.9))) A;
__attribute__((availability(macosx,strict,introduced=10.9))) void f(A*);
The use of A* in the argument list for f is valid here, since f and A
have the same availability.
The fix is to return AR_Unavailable from DeclBase::getAvailability
instead of AR_NotYetIntroduced. This also reverts the special handling
added in r261163, instead relying on the well-tested logic for
AR_Unavailable.
rdar://problem/23791325
llvm-svn: 262915
exactly the same as clang's existing [[clang::fallthrough]] attribute, which
has been updated to have the same semantics. The one significant difference
is that [[fallthrough]] is ill-formed if it's not used immediately before a
switch label (even when -Wimplicit-fallthrough is disabled). To support that,
we now build a CFG of any function that uses a '[[fallthrough]];' statement
to check.
In passing, fix some bugs with our support for statement attributes -- in
particular, diagnose their use on declarations, rather than asserting.
llvm-svn: 262881
David Majnemer