Explicit cast of a void pointer to a pointer type in different address space is
incorrectly classified as bitcast, which causes invalid bitcast in codegen.
The patch fixes that by checking the address space of the source and destination
type and set the correct cast kind.
Differential Revision: https://reviews.llvm.org/D50003
llvm-svn: 338805
Summary:
As discussed in IRC with @rsmith, it is slightly not good to keep that in the `CastExpr` itself:
Given the explicit cast, which is represented in AST as an `ExplicitCastExpr` + `ImplicitCastExpr`'s,
only the `ImplicitCastExpr`'s will be marked as `PartOfExplicitCast`, but not the `ExplicitCastExpr` itself.
Thus, it is only ever `true` for `ImplicitCastExpr`'s, so we don't need to write/read/dump it for `ExplicitCastExpr`'s.
We don't need to worry that we write the `PartOfExplicitCast` in PCH after `CastExpr::path_iterator`,
since the `ExprImplicitCastAbbrev` is only used when the `NumBaseSpecs == 0`, i.e. there is no 'path'.
Reviewers: rsmith, rjmccall, erichkeane, aaron.ballman
Reviewed By: rsmith, erichkeane
Subscribers: vsk, cfe-commits, rsmith
Tags: #clang
Differential Revision: https://reviews.llvm.org/D49838
llvm-svn: 338108
Summary:
As discussed in [[ https://bugs.llvm.org/show_bug.cgi?id=38166 | PR38166 ]], we need to be able to distinqush whether the cast
we are visiting is actually a cast, or part of an `ExplicitCast`.
There are at least four ways to get there:
1. Introduce a new `CastKind`, and use it instead of `IntegralCast` if we are in `ExplicitCast`.
Would work, but does not scale - what if we will need more of these cast kinds?
2. Introduce a flag in `CastExprBits`, whether this cast is part of `ExplicitCast` or not.
Would work, but it isn't immediately clear where it needs to be set.
2. Fix `ScalarExprEmitter::VisitCastExpr()` to visit these `NoOp` casts.
As pointed out by @rsmith, CodeGenFunction::EmitMaterializeTemporaryExpr calls
skipRValueSubobjectAdjustments, which steps over the CK_NoOp cast`,
which explains why we currently don't visit those.
This is probably impossible, as @efriedma points out, that is intentional as per `[class.temporary]` in the standard
3. And the simplest one, just record which NoOp casts we skip.
It just kinda works as-is afterwards.
But, the approach with a flag is the least intrusive one, and is probably the best one overall.
Reviewers: rsmith, rjmccall, majnemer, efriedma
Reviewed By: rsmith
Subscribers: cfe-commits, aaron.ballman, vsk, llvm-commits, rsmith
Differential Revision: https://reviews.llvm.org/D49508
llvm-svn: 337815
Currently clang does not allow implicit cast of a pointer to a pointer type
in different address space but allows C-style cast of a pointer to a pointer
type in different address space. However, there is a bug in Sema causing
incorrect Cast Expr in AST for the latter case, which in turn results in
invalid LLVM IR in codegen.
This is because Sema::IsQualificationConversion returns true for a cast of
pointer to a pointer type in different address space, which in turn allows
a standard conversion and results in a cast expression with no op in AST.
This patch fixes that by let Sema::IsQualificationConversion returns false
for a cast of pointer to a pointer type in different address space, which
in turn disallows standard conversion, implicit cast, and static cast.
Finally it results in an reinterpret cast and correct conversion kind is set.
Differential Revision: https://reviews.llvm.org/D49294
llvm-svn: 337540
qualifiers from all levels matching a multidimensional array.
For example, this allows casting from
pointer to array of array of const volatile int
to
pointer to const pointer to volatile pointer to int
because the multidimensional array part of the source type corresponds
to a part of the destination type that contains both 'const' and
'volatile'.
Differential Revision: https://reviews.llvm.org/D49457
llvm-svn: 337422
This allows more qualification conversions, eg. conversion from
'int *(*)[]' -> 'const int *const (*)[]'
is now permitted, along with all the consequences of that: more types
are similar, more cases are permitted by const_cast, and conversely,
fewer "casting away constness" cases are permitted by reinterpret_cast.
llvm-svn: 336745
The "casts away constness" check doesn't care at all how the different
layers of the source and destination type were formed: for example, if
the source is a pointer and the destination is a pointer-to-member, the
types are still decomposed and their pointee qualifications are still
checked.
This rule is bizarre and somewhat ridiculous, so as an extension we
accept code making use of such reinterpret_casts with a warning outside
of SFINAE contexts.
llvm-svn: 336738
Restrict the following keywords in the OpenCL C++ language mode,
according to Sections 2.2 & 2.9 of the OpenCL C++ 1.0 Specification.
- dynamic_cast
- typeid
- register (already restricted in OpenCL C, update the diagnostic)
- thread_local
- exceptions (try/catch/throw)
- access qualifiers read_only, write_only, read_write
Support the `__global`, `__local`, `__constant`, `__private`, and
`__generic` keywords in OpenCL C++. Leave the unprefixed address
space qualifiers such as global available, i.e., do not mark them as
reserved keywords in OpenCL C++. libclcxx provides explicit address
space pointer classes such as `global_ptr` and `global<T>` that are
implemented using the `__`-prefixed qualifiers.
Differential Revision: https://reviews.llvm.org/D46022
llvm-svn: 331874
Found via codespell -q 3 -I ../clang-whitelist.txt
Where whitelist consists of:
archtype
cas
classs
checkk
compres
definit
frome
iff
inteval
ith
lod
methode
nd
optin
ot
pres
statics
te
thru
Patch by luzpaz! (This is a subset of D44188 that applies cleanly with a few
files that have dubious fixes reverted.)
Differential revision: https://reviews.llvm.org/D44188
llvm-svn: 329399
We do not meaningfully track object const-ness of Objective-C object
types. Silence the -Wcast-qual warning that is issued when casting to or
from Objective-C object types results in losing const qualification.
rdar://problem/33807915
llvm-svn: 310672
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
Stephen Kelly