Summary:
This way, the behavior of that warning flag
more closely resembles that of GCC.
Do note that there is at least one false-negative (see FIXME in tests).
Fixes PR4802.
Testing:
```
ninja check-clang-sema check-clang-semacxx
```
Reviewers: dblaikie, majnemer, rnk
Reviewed By: dblaikie, rnk
Subscribers: mclow.lists, cfe-commits, alexfh, rnk
Differential Revision: https://reviews.llvm.org/D33102
llvm-svn: 307045
Summary:
This way, the behavior of that warning flag
more closely resembles that of GCC.
Do note that there is at least one false-negative (see FIXME in tests).
Fixes PR4802.
Testing:
```
ninja check-clang-sema check-clang-semacxx
```
Reviewers: dblaikie, majnemer, rnk
Reviewed By: dblaikie, rnk
Subscribers: cfe-commits, alexfh, rnk
Differential Revision: https://reviews.llvm.org/D33102
llvm-svn: 305147
We were sometimes doing a function->pointer conversion in
Sema::CheckPlaceholderExpr, which isn't the job of CheckPlaceholderExpr.
So, when we saw typeof(OverloadedFunctionName), where
OverloadedFunctionName referenced a name with only one function that
could have its address taken, we'd give back a function pointer type
instead of a function type. This is incorrect.
I kept the logic for doing the function pointer conversion in
resolveAndFixAddressOfOnlyViableOverloadCandidate because it was more
consistent with existing ResolveAndFix* methods.
llvm-svn: 302506
Summary: After examining the remaining uses of LangOptions.ObjCAutoRefCount, found a some additional places to also check for ObjCWeak not covered by previous test cases. Added a test file to verify all the code paths that were changed.
Reviewers: rsmith, doug.gregor, rjmccall
Reviewed By: rjmccall
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D31007
llvm-svn: 299015
Summary: clang should produce the same errors Objective-C classes that cannot be assigned to weak pointers under both -fobjc-arc and -fobjc-weak. Check for ObjCWeak along with ObjCAutoRefCount when analyzing pointer conversions. Add an -fobjc-weak pass to the existing arc-unavailable-for-weakref test cases to verify the behavior is the same.
Reviewers: rsmith, doug.gregor, rjmccall
Reviewed By: rjmccall
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D31006
llvm-svn: 299014
My original warning was very conservative and I never revisited the
heuristics that were used.
This would have caught http://crbug.com/687251 at compile time.
llvm-svn: 293677
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
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
Summary:
[expr.cast.static] states:
> 3. A glvalue of type “cv1 T1” can be cast to type “rvalue reference to cv2 T2” if “cv2 T2” is reference-compatible
> with “cv1 T1”. The result refers to the object or the specified base class subobject thereof. If T2 is
> an inaccessible or ambiguous base class of T1, a program that necessitates such a cast is
> ill-formed.
>
> 4. Otherwise, an expression e can be explicitly converted to a type T using a static_cast of the form static_-
> cast<T>(e) if the declaration T t(e); is well-formed, for some invented temporary variable t. [...]
Currently when checking p3 Clang will diagnose `static_cast<T&&>(e)` as invalid if the argument is not reference compatible with `T`. However I believe the correct behavior is to also check p4 in those cases. For example:
```
double y = 42;
static_cast<int&&>(y); // this should be OK. 'int&& t(y)' is well formed
```
Note that we still don't check p4 for non-reference-compatible types which are reference-related since `T&& t(e);` should never be well formed in those cases.
Reviewers: rsmith
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D26231
llvm-svn: 285872
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.
Conversions (either implicit or via a valid casting) to pointer types
with lower or equal alignment requirements (e.g. void* or char*)
will silence the warning.
Differential Revision: https://reviews.llvm.org/D20561
llvm-svn: 278483
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.
Conversions (either implicit or via a valid casting) to pointer types
with lower or equal alignment requirements (e.g. void* or char*)
silence the warning.
This change also adds a new error diagnostic when the user attempts to
bind a reference to a packed member, regardless of the alignment.
Differential Revision: https://reviews.llvm.org/D20561
llvm-svn: 275417
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
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:
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
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
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
In {CG,}ExprConstant.cpp, we weren't treating vector splats properly.
This patch makes us treat splats more properly.
Additionally, this patch adds a new cast kind which allows a bool->int
cast to result in -1 or 0, instead of 1 or 0 (for true and false,
respectively), so we can sanely model OpenCL bool->int casts in the AST.
Differential Revision: http://reviews.llvm.org/D14877
llvm-svn: 257559
is complete (with an error produced if not) and a function that merely queries
whether the type is complete. Either way we'll trigger instantiation if
necessary, but only the former will diagnose and recover from missing module
imports.
The intent of this change is to prevent a class of bugs where code would call
RequireCompleteType(..., 0) and then ignore the result. With modules, we must
check the return value and use it to determine whether the definition of the
type is visible.
This also fixes a debug info quality issue: calls to isCompleteType do not
trigger the emission of debug information for a type in limited-debug-info
mode. This allows us to avoid emitting debug information for type definitions
in more cases where we believe it is safe to do so.
llvm-svn: 256049
for the derived class into it. This is mostly just a cleanup, but could in
principle be a bugfix if there is some codepath that reaches here and didn't
previously require a complete type (I couldn't find any such codepath, though).
llvm-svn: 256037
Previously, __weak was silently accepted and ignored in MRC mode.
That makes this a potentially source-breaking change that we have to
roll out cautiously. Accordingly, for the time being, actual support
for __weak references in MRC is experimental, and the compiler will
reject attempts to actually form such references. The intent is to
eventually enable the feature by default in all non-GC modes.
(It is, of course, incompatible with ObjC GC's interpretation of
__weak.)
If you like, you can enable this feature with
-Xclang -fobjc-weak
but like any -Xclang option, this option may be removed at any point,
e.g. if/when it is eventually enabled by default.
This patch also enables the use of the ARC __unsafe_unretained qualifier
in MRC. Unlike __weak, this is being enabled immediately. Since
variables are essentially __unsafe_unretained by default in MRC,
the only practical uses are (1) communication and (2) changing the
default behavior of by-value block capture.
As an implementation matter, this means that the ObjC ownership
qualifiers may appear in any ObjC language mode, and so this patch
removes a number of checks for getLangOpts().ObjCAutoRefCount
that were guarding the processing of these qualifiers. I don't
expect this to be a significant drain on performance; it may even
be faster to just check for these qualifiers directly on a type
(since it's probably in a register anyway) than to do N dependent
loads to grab the LangOptions.
rdar://9674298
llvm-svn: 251041
This fixes a bug where one can take the address of a conditionally
enabled function to drop its enable_if guards. For example:
int foo(int a) __attribute__((enable_if(a > 0, "")));
int (*p)(int) = &foo;
int result = p(-1); // compilation succeeds; calls foo(-1)
Overloading logic has been updated to reflect this change, as well.
Functions with enable_if attributes that are always true are still
allowed to have their address taken.
Differential Revision: http://reviews.llvm.org/D13607
llvm-svn: 250090
I cannot come up with a testcase which would rely on this call to
RequireCompleteType, I believe that it is superfluous given the current
state of clang.
llvm-svn: 247367
Original class was not marked with inheritance attribute and it causes a crash on codegen.
Differential Revision: http://reviews.llvm.org/D11828
llvm-svn: 244428
to consider the storage size of the vector instead of its
sizeof. In other words, ban <3 x int> to <4 x int> casts,
which produced invalid IR anyway.
Also, attempt to be a little more rigorous, or at least
explicit, about when enums are allowed in these casts.
rdar://21901132
llvm-svn: 243069
In the test, y1 is not reference compatible to y2 and we currently assume
the cast is ill-formed so we emit a diagnostic. Instead, in order to honour
the standard, if y1 it's not reference-compatible to y2 then it can't be
converted using a static_cast, and a reinterpret_cast should be tried instead.
Richard Smith provided the correct interpretation of the standard and
explanation about the subtle difference between "can't be cast" and "the cast
is ill-formed". The former applies in this case.
PR: 23802
llvm-svn: 241998
The patch is generated using this command:
$ tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
-checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
work/llvm/tools/clang
To reduce churn, not touching namespaces spanning less than 10 lines.
llvm-svn: 240270
The machinery added to permit a static_cast from void-ptr to fn-ptr
unintentionally gets triggered for c-style casts and function-style
casts. The observable effect was a diagnostic issued inappropriately.
llvm-svn: 239382
The MSVC 2013 and 2015 implementation of std::atomic is specialized for
pointer types. The member functions are implemented using a static_cast
from void-ptr to function-ptr which is not allowed in the standard.
Permit this conversion if -fms-compatibility is present.
This fixes PR23733.
llvm-svn: 238877
clang currently calls MarkVTableUsed() for classes that get their virtual
methods called or that participate in a dynamic_cast. This is unnecessary,
since CodeGen only emits vtables when it generates constructor, destructor, and
vtt code. (*)
Note that Sema::MarkVTableUsed() doesn't cause the emission of a vtable.
Its main user-visible effect is that it instantiates virtual member functions
of template classes, to make sure that if codegen decides to write a vtable
all the entries in the vtable are defined.
While this shouldn't change the behavior of codegen (other than being faster),
it does make clang more permissive: virtual methods of templates (in particular
destructors) end up being instantiated less often. In particular, classes that
have members that are smart pointers to incomplete types will now get their
implicit virtual destructor instantiated less frequently. For example, this
used to not compile but does now compile:
template <typename T> struct OwnPtr {
~OwnPtr() { static_assert((sizeof(T) > 0), "TypeMustBeComplete"); }
};
class ScriptLoader;
struct Base { virtual ~Base(); };
struct Sub : public Base {
virtual void someFun() const {}
OwnPtr<ScriptLoader> m_loader;
};
void f(Sub *s) { s->someFun(); }
The more permissive behavior matches both gcc (where this is not often
observable, since in practice most things with virtual methods have a key
function, and Sema::DefineUsedVTables() skips vtables for classes with key
functions) and cl (which is my motivation for this change) – this fixes
PR20337. See this issue and the review thread for some discussions about
optimizations.
This is similar to r213109 in spirit. r225761 was a prerequisite for this
change.
Various tests relied on "a->f()" marking a's vtable as used (in the sema
sense), switch these to just construct a on the stack. This forces
instantiation of the implicit constructor, which will mark the vtable as used.
(*) The exception is -fapple-kext mode: In this mode, qualified calls to
virtual functions (`a->Base::f()`) still go through the vtable, and since the
vtable pointer off this doesn't point to Base's vtable, this needs to reference
Base's vtable directly. To keep this working, keep referencing the vtable for
virtual calls in apple kext mode.
llvm-svn: 227073
We know that const_cast<char *>((void)Something) is ill-formed, even if
'Something' is dependent because you can't cast from void to a pointer
type.
This fixes PR21845.
llvm-svn: 224299
OpenCL v2.0 s6.5.5 restricts conversion of pointers to different address spaces:
- the named address spaces (__global, __local, and __private) => __generic - implicitly converted;
- __generic => named - with an explicit cast;
- named <=> named - disallowed;
- __constant <=> any other - disallowed.
llvm-svn: 222834
Roman Lebedev