for loop if both members exist.
This resolves a DR whereby an errant 'begin' or 'end' member in a base
class could result in a derived class not being usable as a range with
non-member 'begin' and 'end'.
llvm-svn: 342925
Objects are determined to be smart pointers if they have both a star and arrow
operator. Some implementations of smart pointers have these overloaded
operators in a base class, while the check only searched the derived class.
This fix will also look for the operators in the base class.
llvm-svn: 342794
Summary:
When thread safety annotations are used without capability arguments,
they are assumed to apply to `this` instead. So we warn when either
`this` doesn't exist, or the class is not a capability type.
This is based on earlier work by Josh Gao that was committed in r310403,
but reverted in r310698 because it didn't properly work in template
classes. See also D36237.
The solution is not to go via the QualType of `this`, which is then a
template type, hence the attributes are not known because it could be
specialized. Instead we look directly at the class in which we are
contained.
Additionally I grouped two of the warnings together. There are two
issues here: the existence of `this`, which requires us to be a
non-static member function, and the appropriate annotation on the class
we are contained in. So we don't distinguish between not being in a
class and being static, because in both cases we don't have `this`.
Fixes PR38399.
Reviewers: aaron.ballman, delesley, jmgao, rtrieu
Reviewed By: delesley
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D51901
llvm-svn: 342605
For function pointers, the FunctionDecl of the callee is unknown, so
getDirectCallee will return nullptr. We have to catch that case to avoid
crashing. We assume there is no attribute then.
llvm-svn: 342519
Summary:
We run the tests for -Wthread-safety-{negative,verbose} with the new
attributes as well as the old ones. Also put the macros in a header so
that we don't have to copy them all around.
The warn-thread-safety-parsing.cpp test checks for warnings depending on
the actual attribute name, so it can't undergo the same treatment.
Together with D49275 this should fix PR33754.
Reviewers: aaron.ballman, delesley, grooverdan
Reviewed By: aaron.ballman
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D52141
llvm-svn: 342418
Summary:
Attributes on member classes of class templates and member class templates
of class templates are not currently instantiated. This was discovered by
Richard Smith here:
http://lists.llvm.org/pipermail/cfe-dev/2018-September/059291.html
This commit makes sure that attributes are instantiated properly. This
commit does not fix the broken behavior for member partial and explicit
specializations of class templates.
PR38913
Reviewers: rsmith
Subscribers: dexonsmith, cfe-commits
Differential Revision: https://reviews.llvm.org/D51997
llvm-svn: 342238
A lambda's closure is initialized when the lambda is declared. For
implicit captures, the initialization code emitted from EmitLambdaExpr
references source locations *within the lambda body* in the function
containing the lambda. This results in a poor debugging experience: we
step to the line containing the lambda, then into lambda, out again,
over and over, until every capture's field is initialized.
To improve stepping behavior, assign the starting location of the lambda
to expressions which initialize an implicit capture within it.
rdar://39807527
Differential Revision: https://reviews.llvm.org/D50927
llvm-svn: 342194
Problem was that we were appending to the source location info buffer in the
copy assignment operator (instead of overwriting).
rdar://42746401
llvm-svn: 341869
match when checking for redeclaration of a function template.
This properly handles differences in deduced return types, particularly
when performing redeclaration checks for a friend function template.
llvm-svn: 341778
accessible from the context where aggregate initialization occurs.
rdar://problem/38168772
Differential Revision: https://reviews.llvm.org/D45898
llvm-svn: 341629
destructors.
We previously tried to patch up the exception specification after
completing the class, which went wrong when the exception specification
was needed within the class body (in particular, by a friend
redeclaration of the destructor in a nested class). We now mark the
destructor as having a not-yet-computed exception specification
immediately after creating it.
This requires delaying various checks against the exception
specification (where we'd previously have just got the wrong exception
specification, and now find we have an exception specification that we
can't compute yet) when those checks fire while the class is being
defined.
This also exposed an issue that we were missing a CodeSynthesisContext
for computation of exception specifications (otherwise we'd fail to make
the module containing the definition of the class visible when computing
its members' exception specs). Adding that incidentally also gives us a
diagnostic quality improvement.
This has also exposed an pre-existing problem: making the exception
specification evaluation context a non-SFINAE context (as it should be)
results in a bootstrap failure; PR38850 filed for this.
llvm-svn: 341499
Summary:
It's already allowed to prematurely release a scoped lock, now we also
allow relocking it again, possibly even in another mode.
This is the second attempt, the first had been merged as r339456 and
reverted in r339558 because it caused a crash.
Reviewers: delesley, aaron.ballman
Reviewed By: delesley, aaron.ballman
Subscribers: hokein, cfe-commits
Differential Revision: https://reviews.llvm.org/D49885
llvm-svn: 340459
This commit adds the flag -fno-c++-static-destructors and the attributes
[[clang::no_destroy]] and [[clang::always_destroy]]. no_destroy specifies that a
specific static or thread duration variable shouldn't have it's destructor
registered, and is the default in -fno-c++-static-destructors mode.
always_destroy is the opposite, and is the default in -fc++-static-destructors
mode.
A variable whose destructor is disabled (either because of
-fno-c++-static-destructors or [[clang::no_destroy]]) doesn't count as a use of
the destructor, so we don't do any access checking or mark it referenced. We
also don't emit -Wexit-time-destructors for these variables.
rdar://21734598
Differential revision: https://reviews.llvm.org/D50994
llvm-svn: 340306
Specifically, AttributedType now tracks a regular attr::Kind rather than
having its own parallel Kind enumeration, and AttributedTypeLoc now
holds an Attr* instead of holding an ad-hoc collection of Attr fields.
Differential Revision: https://reviews.llvm.org/D50526
This reinstates r339623, reverted in r339638, with a fix to not fail
template instantiation if we instantiate a QualType with no associated
type source information and we encounter an AttributedType.
llvm-svn: 340215
Summary:
This is for use by clang-tidy's bugprone-use-after-move check -- see
corresponding clang-tidy patch at https://reviews.llvm.org/D49910.
Reviewers: aaron.ballman, rsmith
Reviewed By: aaron.ballman
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D49911
llvm-svn: 339569
__builtin_memmove (in non-type-punning cases).
This is intended to permit libc++ to make std::copy etc constexpr
without sacrificing the optimization that uses memcpy on
trivially-copyable types.
__builtin_strcpy and __builtin_wcscpy are not handled by this change.
They'd be straightforward to add, but we haven't encountered a need for
them just yet.
This reinstates r338455, reverted in r338602, with a fix to avoid trying
to constant-evaluate a memcpy call if either pointer operand has an
invalid designator.
llvm-svn: 338941
Recommit of r335084 after revert in r335516.
... instead of prepending it at the beginning (the original behavior
since implemented in r122535 2010-12-23). This builds up an
AttributeList in the the order in which the attributes appear in the
source.
The reverse order caused nodes for attributes in the AST (e.g. LoopHint)
to be in the reverse order, and therefore printed in the wrong order in
-ast-dump. Some TODO comments mention this. The order was explicitly
reversed for enable_if attribute overload resolution and name mangling,
which is not necessary anymore with this patch.
The change unfortunately has some secondary effect, especially on
diagnostic output. In the simplest cases, the CHECK lines or expected
diagnostic were changed to the the new output. If the kind of
error/warning changed, the attributes' order was changed instead.
This unfortunately causes some 'previous occurrence here' hints to be
textually after the main marker. This typically happens when attributes
are merged, but are incompatible to each other. Interchanging the role
of the the main and note SourceLocation will also cause the case where
two different declaration's attributes (in contrast to multiple
attributes of the same declaration) are merged to be reverse. There is
no easy fix because sometimes previous attributes are merged into a new
declaration's attribute list, sometimes new attributes are added to a
previous declaration's attribute list. Since 'previous occurrence here'
pointing to locations after the main marker is not rare, I left the
markers as-is; it is only relevant when the attributes are declared in
the same declaration anyway.
Differential Revision: https://reviews.llvm.org/D48100
llvm-svn: 338800
It caused asserts during Chromium builds, see reply on the cfe-commits thread.
> This is intended to permit libc++ to make std::copy etc constexpr
> without sacrificing the optimization that uses memcpy on
> trivially-copyable types.
>
> __builtin_strcpy and __builtin_wcscpy are not handled by this change.
> They'd be straightforward to add, but we haven't encountered a need for
> them just yet.
llvm-svn: 338602
This patch adds support for a new attribute, [[clang::lifetimebound]], that
indicates that the lifetime of a function result is related to one of the
function arguments. When walking an initializer to make sure that the lifetime
of the initial value is at least as long as the lifetime of the initialized
object, we step through parameters (including the implicit object parameter of
a non-static member function) that are marked with this attribute.
There's nowhere to write an attribute on the implicit object parameter, so in
lieu of that, it may be applied to a function type (where it appears
immediately after the cv-qualifiers and ref-qualifier, which is as close to a
declaration of the implicit object parameter as we have). I'm currently
modeling this in the AST as the attribute appertaining to the function type.
Differential Revision: https://reviews.llvm.org/D49922
llvm-svn: 338464
__builtin_memmove (in non-type-punning cases).
This is intended to permit libc++ to make std::copy etc constexpr
without sacrificing the optimization that uses memcpy on
trivially-copyable types.
__builtin_strcpy and __builtin_wcscpy are not handled by this change.
They'd be straightforward to add, but we haven't encountered a need for
them just yet.
llvm-svn: 338455
Previously, we just canonicalized the type, but this lead to crashes with
parameter types that referred to ParmVarDecls of the constructor. There may be
more cases that this TreeTransform needs to handle though, such as a constructor
parameter type referring to a member in an unevaluated context. Canonicalization
doesn't address these cases either though, so we can address them as-needed in
follow-up commits.
rdar://41330135
Differential revision: https://reviews.llvm.org/D49439
llvm-svn: 338165
Check each case value in turn while parsing it, performing the
conversion to the switch type within the context of the expression
itself. This will become necessary in order to properly handle cleanups
for temporaries created as part of the case label (in an upcoming
patch). For now it's just good hygiene.
This necessitates moving the checking for the switch condition itself to
earlier, so that the destination type is available when checking the
case labels.
As a nice side-effect, we get slightly improved diagnostic quality and
error recovery by separating the case expression checking from the case
statement checking and from tracking whether there are discarded case
labels.
llvm-svn: 338056
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
Clang would crash when instantiating a BlockDecl that appeared in a
default-member-initializer of a class template. Fix this by deferring the
instantiation until we instantate the BlockExpr.
rdar://41200624
Differential revision: https://reviews.llvm.org/D49688
llvm-svn: 337766
This reinstates r337627, reverted in r337671, with a fix to correctly
handle the lvalueness of array subscript expressions on pointers.
llvm-svn: 337726
Discovered because of: https://bugs.llvm.org/show_bug.cgi?id=38235
It seems to me that a scoped enum should NOT be an integral constant expression
without a cast, so this seems like a sensical change.
Attributes that check for an integer parameter simply use this function to
ensure that they have an integer, so it was previously allowing a scoped enum.
Also added a test based on Richard's feedback to ensure that case labels still work.
Differential Revision: https://reviews.llvm.org/D49599
llvm-svn: 337585
As documented here: https://software.intel.com/en-us/node/682969 and
https://software.intel.com/en-us/node/523346. cpu_dispatch multiversioning
is an ICC feature that provides for function multiversioning.
This feature is implemented with two attributes: First, cpu_specific,
which specifies the individual function versions. Second, cpu_dispatch,
which specifies the location of the resolver function and the list of
resolvable functions.
This is valuable since it provides a mechanism where the resolver's TU
can be specified in one location, and the individual implementions
each in their own translation units.
The goal of this patch is to be source-compatible with ICC, so this
implementation diverges from the ICC implementation in a few ways:
1- Linux x86/64 only: This implementation uses ifuncs in order to
properly dispatch functions. This is is a valuable performance benefit
over the ICC implementation. A future patch will be provided to enable
this feature on Windows, but it will obviously more closely fit ICC's
implementation.
2- CPU Identification functions: ICC uses a set of custom functions to identify
the feature list of the host processor. This patch uses the cpu_supports
functionality in order to better align with 'target' multiversioning.
1- cpu_dispatch function def/decl: ICC's cpu_dispatch requires that the function
marked cpu_dispatch be an empty definition. This patch supports that as well,
however declarations are also permitted, since the linker will solve the
issue of multiple emissions.
Differential Revision: https://reviews.llvm.org/D47474
llvm-svn: 337552
C++2a via http://wg21.link/p0355 permits the library
literals of 'd' and 'y'. This patch enables them in the
Lexer so that they can be properly parsed.
Note that 'd' gets confused with the hex character, so
modifications to how octal, binary, and decimal numbers are
parsed were required. Since this is simply making previously
invalid code legal, this should be fine.
Hex still greedily parses the 'd' as a hexit, since it would
a: violate [lex.ext]p1
b: break existing code.
Differential Revision: https://reviews.llvm.org/D49504
llvm-svn: 337454
This patch uses CodeSegAttr to represent __declspec(code_seg) rather than
building on the existing support for #pragma code_seg.
The code_seg declspec is applied on functions and classes. This attribute
enables the placement of code into separate named segments, including compiler-
generated codes and template instantiations.
For more information, please see the following:
https://msdn.microsoft.com/en-us/library/dn636922.aspx
This patch fixes the regression for the support for attribute ((section).
746b78de78
Patch by Soumi Manna (Manna)
Differential Revision: https://reviews.llvm.org/D48841
llvm-svn: 337420
This change implements C++ DR1696, which makes initialization of a
reference member of a class from a temporary object ill-formed. The
standard wording here is imprecise, but we interpret it as meaning that
any time a mem-initializer would result in lifetime extension, the
program is ill-formed.
This reinstates r337226, reverted in r337255, with a fix for the
InitializedEntity alignment problem that was breaking ARM buildbots.
llvm-svn: 337329
This reverts commit r337152. This applies to non-constants too. The real
explanation is that the capture is not ODR-used, but putting that into
the warning message seems ... worse.
llvm-svn: 337278
This change breaks on ARM because pointers to clang::InitializedEntity are only
4 byte aligned and do not have 3 bits to store values. A possible solution
would be to change the fields in clang::InitializedEntity to enforce a bigger
alignment requirement.
The error message is
llvm/include/llvm/ADT/PointerIntPair.h:132:3: error: static_assert failed "PointerIntPair with integer size too large for pointer"
static_assert(IntBits <= PtrTraits::NumLowBitsAvailable,
include/llvm/ADT/PointerIntPair.h:73:13: note: in instantiation of template class 'llvm::PointerIntPairInfo<const clang::InitializedEntity *, 3, llvm::PointerLikeTypeTraits<const clang::InitializedEntity *> >' requested here
Value = Info::updateInt(Info::updatePointer(0, PtrVal),
llvm/include/llvm/ADT/PointerIntPair.h:51:5: note: in instantiation of member function 'llvm::PointerIntPair<const clang::InitializedEntity *, 3, (anonymous namespace)::LifetimeKind, llvm::PointerLikeTypeTraits<const clang::InitializedEntity *>, llvm::PointerIntPairInfo<const clang::InitializedEntity *, 3, llvm::PointerLikeTypeTraits<const clang::InitializedEntity *> > >::setPointerAndInt' requested here
setPointerAndInt(PtrVal, IntVal);
^
llvm/tools/clang/lib/Sema/SemaInit.cpp:6237:12: note: in instantiation of member function 'llvm::PointerIntPair<const clang::InitializedEntity *, 3, (anonymous namespace)::LifetimeKind, llvm::PointerLikeTypeTraits<const clang::InitializedEntity *>, llvm::PointerIntPairInfo<const clang::InitializedEntity *, 3, llvm::PointerLikeTypeTraits<const clang::InitializedEntity *> > >::PointerIntPair' requested here
return {Entity, LK_Extended};
Full log here:
http://lab.llvm.org:8011/builders/clang-cmake-armv7-global-isel/builds/1330http://lab.llvm.org:8011/builders/clang-cmake-armv7-full/builds/1394
llvm-svn: 337255
This change implements C++ DR1696, which makes initialization of a
reference member of a class from a temporary object ill-formed. The
standard wording here is imprecise, but we interpret it as meaning that
any time a mem-initializer would result in lifetime extension, the
program is ill-formed.
llvm-svn: 337226
This is one of the darker corners of C++, make it clear that this is
about constants and rephrase it a bit.
Before: lambda capture 'i' is not required to be captured for this use
After: lambda capture of constant 'i' is not required for this use
llvm-svn: 337152
As listed in the above PRs, vector_size doesn't allow
dependent types/values. This patch introduces a new
DependentVectorType to handle a VectorType that has a dependent
size or type.
In the future, ALL the vector-types should be able to create one
of these to handle dependent types/sizes as well. For example,
DependentSizedExtVectorType could likely be switched to just use
this instead, though that is left as an exercise for the future.
Differential Revision: https://reviews.llvm.org/D49045
llvm-svn: 337036
Summary:
A forward-declared coroutine_traits should trip an error; we need
a complete type.
Unfortunately, in debug mode only, we trip an assert when attempting
to provide the fully qualified type for the error message.
If you try to compile a program with a forward-declared
coroutine_traits in debug mode, clang will crash.
I've included a test for the behavior and removed the q modifier
on the error message. This prevents the crash in debug mode and
does not change the behavior for the error message on a
forward-declaration of a coroutine_traits type.
Test Plan:
I've included a test for the forward-declaration.
Patch by Tanoy Sinha!
Reviewers: modocache, GorNishanov
Reviewed By: modocache
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D49099
llvm-svn: 336748
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 member init list for the sole constructor for CodeGenFunction
has gotten out of hand, so this patch moves the non-parameter-dependent
initializations into the member value inits.
llvm-svn: 336726
BindingDecls have null type until their initializer is processed, so we can't
assume that a correction candidate has non-null type.
rdar://41559582
llvm-svn: 336634
deprecated.
Add a -Wdeprecated warning for this in C++2a onwards. (In C++17 and
before, there isn't a reasonable alternative because [=,this] is
ill-formed.)
llvm-svn: 336480
Summary:
Can happen when getConstructorName is called on invalid decls,
specifically the ones that do not have the injected class name.
Reviewers: bkramer, rsmith
Reviewed By: rsmith
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D48880
llvm-svn: 336244
The constexpr evaluator was erroring out because these templates weren't
defined. Despite being used in a discarded statement, we still need to constexpr
evaluate them, which means that we need to instantiate them. Fixes PR37585.
Differential revision: https://reviews.llvm.org/D48322
llvm-svn: 336233
Summary:
Add citations to the Coroutines TS to the `isValidCoroutineContext`
function, as well as a FIXME and test for [expr.await]p2, which states
a co_await expression cannot be used in a default argument.
Test Plan: check-clang
Reviewers: GorNishanov, EricWF
Reviewed By: GorNishanov
Subscribers: rsmith, cfe-commits
Differential Revision: https://reviews.llvm.org/D48519
llvm-svn: 335420
dead code.
This is important for C++ templates that essentially compute the valid
input in a way that is constant and will cause all the invalid cases to
be dead code that is deleted. Code in the wild actually does this and
GCC also accepts these kinds of patterns so it is important to support
it.
To make this work, we provide a non-error path to diagnose these issues,
and use a default-error warning instead. This keeps the relatively
strict handling but prevents nastiness like SFINAE on these errors. It
also allows us to safely use the system to diagnose this only when it
occurs at runtime (in emitted code).
Entertainingly, this required fixing the syntax in various other ways
for the x86 test because we never bothered to diagnose that the returns
were invalid.
Since debugging these compile failures was super confusing, I've also
improved the diagnostic to actually say what the value was. Most of the
checks I've made ignore this to simplify maintenance, but I've checked
it in a few places to make sure the diagnsotic is working.
Depends on D48462. Without that, we might actually crash some part of
the compiler after bypassing the error here.
Thanks to Richard, Ben Kramer, and especially Craig Topper for all the
help here.
Differential Revision: https://reviews.llvm.org/D48464
llvm-svn: 335309
... instead of prepending it at the beginning (the original behavior
since implemented in r122535 2010-12-23). This builds up an
AttributeList in the the order in which the attributes appear in the
source.
The reverse order caused nodes for attributes in the AST (e.g. LoopHint)
to be in the reverse, and therefore printed in the wrong order by
-ast-dump. Some TODO comments mention this. The order was explicitly
reversed for enable_if attribute overload resolution and name mangling,
which is not necessary anymore with this patch.
The change unfortunately has some secondary effects, especially for
diagnostic output. In the simplest cases, the CHECK lines or expected
diagnostic were changed to the the new output. If the kind of
error/warning changed, the attribute's order was changed instead.
It also causes some 'previous occurrence here' hints to be textually
after the main marker. This typically happens when attributes are
merged, but are incompatible. Interchanging the role of the the main
and note SourceLocation will also cause the case where two different
declaration's attributes (in contrast to multiple attributes of the
same declaration) are merged to be reversed. There is no easy fix
because sometimes previous attributes are merged into a new
declaration's attribute list, sometimes new attributes are added to a
previous declaration's attribute list. Since 'previous occurrence here'
pointing to locations after the main marker is not rare, I left the
markers as-is; it is only relevant when the attributes are declared in
the same declaration anyway, which often is on the same line.
Differential Revision: https://reviews.llvm.org/D48100
llvm-svn: 335084
Diagnostics for narrowing conversions in initializer lists are currently
DefaultIgnored in Microsoft mode. But MSVC 2015 did add warnings about
narrowing conversions (C2397), so clang-cl can remove its special case code if
MSCompatibilityVersion is new enough.
(In MSVC, C2397 is just a warning and in clang it's default-mapped to an error,
but it can be remapped, and disabled with -Wno-c++11-narrowing, so that should
be fine.)
Fixes PR37314.
https://reviews.llvm.org/D48296
llvm-svn: 335082
Summary:
This is the second attempt of r333500 (Update NRVO logic to support early return).
The previous one was reverted for a miscompilation for an incorrect NRVO set up on templates such as:
```
struct Foo {};
template <typename T>
T bar() {
T t;
if (false)
return T();
return t;
}
```
Where, `t` is marked as non-NRVO variable before its instantiation. However, while its instantiation, it's left an NRVO candidate, turned into an NRVO variable later.
Reviewers: rsmith
Reviewed By: rsmith
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D47586
llvm-svn: 335019
argument, use the context in which it is used for checking its
accessibility.
This fixes PR32898.
rdar://problem/33737747
Differential Revision: https://reviews.llvm.org/D36918
llvm-svn: 334569
As reported here (https://bugs.llvm.org/show_bug.cgi?id=19808)
and discovered independently when looking at plum-hall tests,
we incorrectly implemented over.ics.rank, which says "A conversion
that is not a conversion of a pointer, or pointer to member, to bool
is better than another conversion that is such a conversion.".
In the current Draft (N4750), this is phrased slightly differently in
paragraph 4.1: A conversion that does not convert a pointer, a pointer
to member, or std::nullptr_t to bool is better than one that does.
The comment on isPointerConversionToBool (the changed function)
also confirms that this is the case (note outdated reference):
isPointerConversionToBool - Determines whether this conversion is
a conversion of a pointer or pointer-to-member to bool. This is
used as part of the ranking of standard conversion sequences
(C++ 13.3.3.2p4).
However, despite this comment, it didn't check isMemberPointerType
on the 'FromType', presumably incorrectly assuming that 'isPointerType'
matched it. This patch fixes this by adding isMemberPointerType to
this function. Additionally, member function pointers are just
MemberPointerTypes that point to functions insted of data, so that
is fixed in this patch as well.
llvm-svn: 334503
An attempt to use dynamic_cast while rtti is disabled, used to emit the error:
cannot use dynamic_cast with -fno-rtti
and a similar one for typeid.
This patch changes that to:
use of dynamic_cast requires -frtti
Differential Revision: https://reviews.llvm.org/D47291
llvm-svn: 334153
For example, given:
enum __attribute__((deprecated)) T *p;
-ast-print produced:
enum T *p;
The attribute was lost because the enum forward decl was lost.
Another example is the loss of enum forward decls from C++ namespaces
(in MS compatibility mode).
The trouble was that the EnumDecl node was suppressed, as revealed by
-ast-dump. The suppression of the EnumDecl was intentional in
r116122, but I don't understand why. The suppression isn't needed for
the test suite to behave.
Reviewed by: rsmith
Differential Revision: https://reviews.llvm.org/D46846
llvm-svn: 333574
Summary:
The previous implementation misses an opportunity to apply NRVO (Named Return Value
Optimization) below. That discourages user to write early return code.
```
struct Foo {};
Foo f(bool b) {
if (b)
return Foo();
Foo oo;
return oo;
}
```
That is, we can/should apply RVO for a local variable if:
* It's directly returned by at least one return statement.
* And, all reachable return statements in its scope returns the variable directly.
While, the previous implementation disables the RVO in a scope if there are multiple return
statements that refers different variables.
On the new algorithm, local variables are in NRVO_Candidate state at first, and a return
statement changes it to NRVO_Disabled for all visible variables but the return statement refers.
Then, at the end of the function AST traversal, NRVO is enabled for variables in NRVO_Candidate
state and refers from at least one return statement.
Reviewers: rsmith
Reviewed By: rsmith
Subscribers: xbolva00, Quuxplusone, arthur.j.odwyer, cfe-commits
Differential Revision: https://reviews.llvm.org/D47067
llvm-svn: 333500
Codebases that need to be compatible with the Microsoft ABI can pass
this flag to avoid issues caused by the lack of a fixed ABI for
incomplete member pointers.
Differential Revision: https://reviews.llvm.org/D47503
llvm-svn: 333498
Summary:
This patch adds the newly added `%sub` diagnostic modifier to cleanup repetition in the overload candidate diagnostics.
I think this should be good to go.
@rsmith: Some of the notes now emit `function template` where they only said `function` previously. It seems OK to me, but I would like your sign off on it.
Reviewers: rsmith, EricWF
Reviewed By: EricWF
Subscribers: cfe-commits, rsmith
Differential Revision: https://reviews.llvm.org/D47101
llvm-svn: 333485
unusual types.
Following the observed behavior of GCC, we now return -1 for vector types
(along with all of our extensions that GCC doesn't support), and for atomic
types we classify the underlying type.
GCC appears to have changed its classification for function and array arguments
between version 5 and version 6. Previously it would classify them as pointers
in C and as functions or arrays in C++, but from version 6 onwards, it
classifies them as pointers. We now follow the more recent GCC behavior rather
than emulating what I can only assume to be a historical bug in their C++
support for this builtin.
Finally, no version of GCC that I can find has ever used the "method"
classification for C++ pointers to member functions. Instead, GCC classifies
them as record types, presumably reflecting an internal implementation detail,
but whatever the reason we now produce compatible results.
llvm-svn: 333126
It caused asserts, see PR37560.
> Use zeroinitializer for (trailing zero portion of) large array initializers
> more reliably.
>
> Clang has two different ways it emits array constants (from InitListExprs and
> from APValues), and both had some ability to emit zeroinitializer, but neither
> was able to catch all cases where we could use zeroinitializer reliably. In
> particular, emitting from an APValue would fail to notice if all the explicit
> array elements happened to be zero. In addition, for large arrays where only an
> initial portion has an explicit initializer, we would emit the complete
> initializer (which could be huge) rather than emitting only the non-zero
> portion. With this change, when the element would have a suffix of more than 8
> zero elements, we emit the array constant as a packed struct of its initial
> portion followed by a zeroinitializer constant for the trailing zero portion.
>
> In passing, I found a bug where SemaInit would sometimes walk the entire array
> when checking an initializer that only covers the first few elements; that's
> fixed here to unblock testing of the rest.
>
> Differential Revision: https://reviews.llvm.org/D47166
llvm-svn: 333067
more reliably.
Clang has two different ways it emits array constants (from InitListExprs and
from APValues), and both had some ability to emit zeroinitializer, but neither
was able to catch all cases where we could use zeroinitializer reliably. In
particular, emitting from an APValue would fail to notice if all the explicit
array elements happened to be zero. In addition, for large arrays where only an
initial portion has an explicit initializer, we would emit the complete
initializer (which could be huge) rather than emitting only the non-zero
portion. With this change, when the element would have a suffix of more than 8
zero elements, we emit the array constant as a packed struct of its initial
portion followed by a zeroinitializer constant for the trailing zero portion.
In passing, I found a bug where SemaInit would sometimes walk the entire array
when checking an initializer that only covers the first few elements; that's
fixed here to unblock testing of the rest.
Differential Revision: https://reviews.llvm.org/D47166
llvm-svn: 333044
If a variable has an initializer, codegen tries to build its value. If
the variable is large in size, building its value requires substantial
resources. It causes strange behavior from user viewpoint: compilation
of huge zero initialized arrays like:
char data_1[2147483648u] = { 0 };
consumes enormous amount of time and memory.
With this change codegen tries to determine if variable initializer is
equivalent to zero initializer. In this case variable value is not
constructed.
This change fixes PR18978.
Differential Revision: https://reviews.llvm.org/D46241
llvm-svn: 332847
Summary:
There are cases where the same string or select is repeated verbatim in a lot of diagnostics. This can be a pain to maintain and update. Tablegen provides no way stash the common text somewhere and reuse it in the diagnostics, until now!
This patch allows diagnostic texts to contain `%sub{<definition-name>}`, where `<definition-name>` names a Tablegen record of type `TextSubstitution`. These substitutions are done early, before the diagnostic string is otherwise processed. All `%sub` modifiers will be replaced before the diagnostic definitions are emitted.
The substitution must specify all arguments used by the substitution, and modifier indexes in the substitution are re-numbered accordingly. For example:
```
def select_ovl_candidate : TextSubstitution<"%select{function|constructor}0%select{| template| %2}1">;
```
when used as
```
"candidate `%sub{select_ovl_candidate}3,2,1 not viable"
```
will act as if we wrote:
```
"candidate %select{function|constructor}3%select{| template| %1}2 not viable"
```
Reviewers: rsmith, rjmccall, aaron.ballman, a.sidorin
Reviewed By: rjmccall
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D46740
llvm-svn: 332799
Clang used to pass the base lvalue of a non-type template parameter
to the template instantiation phase when the base part is __uuidof
and it's running in C++17 mode.
However, that drops its LValuePath, and unintentionally transforms
&__uuidof(...) to __uuidof(...).
This CL fixes that by passing whole expr. Fixes PR24986.
https://reviews.llvm.org/D46820?id=146557
Patch from Taiju Tsuiki <tzik@chromium.org>!
llvm-svn: 332614
For example, given:
struct T1 {
struct T2 *p0;
};
-ast-print produced:
struct T1 {
struct T2;
struct T2 *p0;
};
Compiling that produces a warning that the first struct T2 declaration
does not declare anything.
Details:
A tag decl group is one or more decls that share a type specifier that
is a tag decl (that is, a struct/union/class/enum decl). Within
functions, the parser builds such a tag decl group as part of a
DeclStmt. However, in decl contexts, such as file scope or a member
list, the parser does not group together the members of a tag decl
group. Previously, detection of tag decl groups during printing was
implemented but only if the tag decl was unnamed. Otherwise, as in
the above example, the members of the group did not print together and
so sometimes introduced warnings.
This patch extends detection of tag decl groups in decl contexts to
any tag decl that is recorded in the AST as not free-standing.
Reviewed by: rsmith
Differential Revision: https://reviews.llvm.org/D45465
llvm-svn: 332314
Like other conversion warnings, allow float overflow warnings to be disabled
in known dead paths of template instantiation. This often occurs when a
template template type is a numeric type and the template will check the
range of the numeric type before performing the conversion.
llvm-svn: 332310
For 'x::template y', consistently give a "no member named 'y' in 'x'"
diagnostic if there is no such member, and give a 'template keyword not
followed by a template' name error if there is such a member but it's not a
template. In the latter case, add a note pointing at the non-template.
Don't suggest inserting a 'template' keyword in 'X::Y<' if X is dependent
if the lookup of X::Y was actually not a dependent lookup and found only
non-templates.
llvm-svn: 332076
As Eli brought up here: https://reviews.llvm.org/D46535
I'd previously messed up this fix by missing conversions
that are just slightly outside the range. This patch fixes
this by no longer ignoring the return value of
convertToInteger. Additionally, one of the error messages
wasn't very sensical (mentioning out of range value, when it
really was not), so it was cleaned up as well.
llvm-svn: 331812
This patch addresses some mostly trivial post-commit review comments received
on r331677.
Additionally, this patch fixes an assertion in `getNarrowingKind` caused by
the use of an uninitialized value from `checkThreeWayNarrowingConversion`.
llvm-svn: 331707
In order to match our mangling scheme, use a different set of numbers for
decomposition declarations, and consider all binding names when forming the
numbering. This does not yet affect any mangled names we produce, because
local decomposition declarations can't yet have linkage, but a C++ standard
proposal to change that is currently being processed.
llvm-svn: 331692
Summary:
This patch tackles long hanging fruit for the builtin operator<=> expressions. It is currently needs some cleanup before landing, but I want to get some initial feedback.
The main changes are:
* Lookup, build, and store the required standard library types and expressions in `ASTContext`. By storing them in ASTContext we don't need to store (and duplicate) the required expressions in the BinaryOperator AST nodes.
* Implement [expr.spaceship] checking, including diagnosing narrowing conversions.
* Implement `ExprConstant` for builtin spaceship operators.
* Implement builitin operator<=> support in `CodeGenAgg`. Initially I emitted the required comparisons using `ScalarExprEmitter::VisitBinaryOperator`, but this caused the operand expressions to be emitted once for every required cmp.
* Implement [builtin.over] with modifications to support the intent of P0946R0. See the note on `BuiltinOperatorOverloadBuilder::addThreeWayArithmeticOverloads` for more information about the workaround.
Reviewers: rsmith, aaron.ballman, majnemer, rnk, compnerd, rjmccall
Reviewed By: rjmccall
Subscribers: rjmccall, rsmith, aaron.ballman, junbuml, mgorny, cfe-commits
Differential Revision: https://reviews.llvm.org/D45476
llvm-svn: 331677
As identified and briefly discussed here:
https://bugs.llvm.org/show_bug.cgi?id=37305
Converting a floating point number to an integer type when
the integral part is out of the range of the integer type is
undefined behavior in C. Additionally, CodeGen emits an undef
in this situation.
HOWEVER, we've been giving a warning that says that the value is
changed. This patch corrects the warning to list that it is actually
undefined behavior.
Differential Revision: https://reviews.llvm.org/D46535
llvm-svn: 331673
This implements the rule intended by the standard (see LWG 2358)
and the rule intended by the Itanium C++ ABI (see
https://github.com/itanium-cxx-abi/cxx-abi/pull/51), and makes
Clang match the behavior of GCC, ICC, and MSVC.
A pedantic reading of both the standard and the ABI indicate that Clang
is currently technically correct, but that's not worth much when it's
clear that the wording is wrong in both those places.
This is an ABI break for classes that derive from a class that is empty
other than one or more unnamed non-zero-length bit-fields. Such cases
are expected to be rare, but -fclang-abi-compat=6 restores the old
behavior just in case.
Differential Revision: https://reviews.llvm.org/D45174
llvm-svn: 331620
Calling convention attributes notionally appertain to the function type -- they modify the mangling of the function, change the behavior of assignment operations, etc. This commit allows the calling convention attributes to be written in the type position as well as the declaration position.
llvm-svn: 331459
This is not yet part of any C++ working draft, and so is controlled by the flag
-fchar8_t rather than a -std= flag. (The GCC implementation is controlled by a
flag with the same name.)
This implementation is experimental, and will be removed or revised
substantially to match the proposal as it makes its way through the C++
committee.
llvm-svn: 331244
Clang incorrectly applied the packed attribute to base classes. Per GCC's
documentation and as can be observed from its behavior, packed only applies to
members, not base classes.
This change is conditioned behind -fclang-abi-compat so that an ABI break can
be avoided by users if desired.
Differential Revision: https://reviews.llvm.org/D46218
llvm-svn: 331136
template arguments.
This fixes some cases where we'd incorrectly accept "A::template B" when B is a
kind of template that requires template arguments (in particular, a variable
template or a concept).
llvm-svn: 331013
a preceding 'template' keyword.
We only diagnose in the dependent case (wherein we used to crash). Another bug
prevents the diagnostic from appearing in the non-template case.
llvm-svn: 330894
This makes it return the right result in a couple of edge cases. The
wide versions always do the comparison on the underlying wchar_t type.
llvm-svn: 330656
Summary:
It seems there isn't much enthusiasm for `-wtest` D45685.
This is more conservative version, which i had in the very first
revision of D44883, but that 'erroneously' got removed because of the review.
**Based on some [irc] discussions, it must really be documented that
we want all the new diagnostics to have their own flags, to ease
rollouts, transitions, etc.**
Please do note that i'm only adding `-Wno-self-assign-overloaded`,
but not `-Wno-self-assign-field-overloaded`, because i'm honestly
not aware of any false-positives from the `-field` variant,
but i can just as easily add it if wanted.
https://reviews.llvm.org/D44883#1068561
Reviewers: dblaikie, aaron.ballman, thakis, rjmccall, rsmith
Reviewed By: dblaikie
Subscribers: Quuxplusone, chandlerc, cfe-commits
Differential Revision: https://reviews.llvm.org/D45766
llvm-svn: 330651
Following: https://llvm.org/svn/llvm-project/cfe/trunk@329804
For C++17 the wording of [over.built] p4 excluded bool:
For every pair (T , vq), where T is an arithmetic type other than bool, there exist
candidate operator functions of the form
vq T & operator++(vq T &);
T operator++(vq T &, int);
Differential Revision: https://reviews.llvm.org/D45569
llvm-svn: 330254
Summary:
This patch adds two new diagnostics, which are off by default:
**-Wreturn-std-move**
This diagnostic is enabled by `-Wreturn-std-move`, `-Wmove`, or `-Wall`.
Diagnose cases of `return x` or `throw x`, where `x` is the name of a local variable or parameter, in which a copy operation is performed when a move operation would have been available. The user probably expected a move, but they're not getting a move, perhaps because the type of "x" is different from the return type of the function.
A place where this comes up in the wild is `stdext::inplace_function<Sig, N>` which implements conversion via a conversion operator rather than a converting constructor; see https://github.com/WG21-SG14/SG14/issues/125#issue-297201412
Another place where this has come up in the wild, but where the fix ended up being different, was
try { ... } catch (ExceptionType ex) {
throw ex;
}
where the appropriate fix in that case was to replace `throw ex;` with `throw;`, and incidentally to catch by reference instead of by value. (But one could contrive a scenario where the slicing was intentional, in which case throw-by-move would have been the appropriate fix after all.)
Another example (intentional slicing to a base class) is dissected in https://github.com/accuBayArea/Slides/blob/master/slides/2018-03-07.pdf
**-Wreturn-std-move-in-c++11**
This diagnostic is enabled only by the exact spelling `-Wreturn-std-move-in-c++11`.
Diagnose cases of "return x;" or "throw x;" which in this version of Clang *do* produce moves, but which prior to Clang 3.9 / GCC 5.1 produced copies instead. This is useful in codebases which care about portability to those older compilers.
The name "-in-c++11" is not technically correct; what caused the version-to-version change in behavior here was actually CWG 1579, not C++14. I think it's likely that codebases that need portability to GCC 4.9-and-earlier may understand "C++11" as a colloquialism for "older compilers." The wording of this diagnostic is based on feedback from @rsmith.
**Discussion**
Notice that this patch is kind of a negative-space version of Richard Trieu's `-Wpessimizing-move`. That diagnostic warns about cases of `return std::move(x)` that should be `return x` for speed. These diagnostics warn about cases of `return x` that should be `return std::move(x)` for speed. (The two diagnostics' bailiwicks do not overlap: we don't have to worry about a `return` statement flipping between the two states indefinitely.)
I propose to write a paper for San Diego that would relax the implicit-move rules so that in C++2a the user //would// see the moves they expect, and the diagnostic could be re-worded in a later version of Clang to suggest explicit `std::move` only "in C++17 and earlier." But in the meantime (and/or forever if that proposal is not well received), this diagnostic will be useful to detect accidental copy operations.
Reviewers: rtrieu, rsmith
Reviewed By: rsmith
Subscribers: lebedev.ri, Rakete1111, rsmith, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D43322
Patch by Arthur O'Dwyer.
llvm-svn: 329914
C++ [over.built] p4:
"For every pair (T, VQ), where T is an arithmetic type other than bool, and VQ is either volatile or empty, there exist candidate operator functions of the form
VQ T& operator--(VQ T&);
T operator--(VQ T&, int);
"
The bool type is in position LastPromotedIntegralType in BuiltinOperatorOverloadBuilder::getArithmeticType::ArithmeticTypes, but addPlusPlusMinusMinusArithmeticOverloads() was expecting it at position 0.
Differential Revision: https://reviews.llvm.org/D44988
rdar://problem/34255516
llvm-svn: 329804
an APValue and retrieve it from map Temporaries.
The version number is needed when a single AST node is visited multiple
times and is used to create APValues that are required to be distinct
from each other (for example, MaterializeTemporaryExprs in default
arguments and VarDecls in loops).
rdar://problem/36505742
Differential Revision: https://reviews.llvm.org/D42776
llvm-svn: 329671
Summary:
Currently clang doesn't do qualified lookup when building indirect field decl references. This causes ambiguity when the field is in a base class to which there are multiple valid paths even though a qualified name is used.
For example:
```
class B {
protected:
int i;
union { int j; };
};
class X : public B { };
class Y : public B { };
class Z : public X, public Y {
int a() { return X::i; } // works
int b() { return X::j; } // fails
};
```
Reviewers: rsmith, aaron.ballman, rjmccall
Reviewed By: rjmccall
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D45411
llvm-svn: 329521
Summary:
Currently clang doesn't do qualified lookup when building indirect field decl references. This causes ambiguity when the field is in a base class to which there are multiple valid paths even though a qualified name is used.
For example:
```
class B {
protected:
int i;
union { int j; };
};
class X : public B { };
class Y : public B { };
class Z : public X, public Y {
int a() { return X::i; } // works
int b() { return X::j; } // fails
};
```
Reviewers: rsmith, aaron.ballman, rjmccall
Reviewed By: rjmccall
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D45411
llvm-svn: 329519
Summary:
Currently Clang fails to propagate qualifiers from the `CXXThisExpr` to the rebuilt `FieldDecl` for IndirectFieldDecls. For example:
```
template <class T> struct Foo {
struct { int x; };
int y;
void foo() const {
static_assert(__is_same(int const&, decltype((y))));
static_assert(__is_same(int const&, decltype((x)))); // assertion fails
}
};
template struct Foo<int>;
```
The fix is to delegate rebuilding of the MemberExpr to `BuildFieldReferenceExpr` which correctly propagates the qualifiers.
Reviewers: rsmith, lebedev.ri, aaron.ballman, bkramer, rjmccall
Reviewed By: rjmccall
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D45412
llvm-svn: 329517
Summary:
This has just bit me, so i though it would be nice to avoid that next time :)
Motivational case:
https://godbolt.org/g/cq9UNk
Basically, it's likely to happen if you don't like shadowing issues,
and use `-Wshadow` and friends. And it won't be diagnosed by clang.
The reason is, these self-assign diagnostics only work for builtin assignment
operators. Which makes sense, one could have a very special operator=,
that does something unusual in case of self-assignment,
so it may make sense to not warn on that.
But while it may be intentional in some cases, it may be a bug in other cases,
so it would be really great to have some diagnostic about it...
Reviewers: aaron.ballman, rsmith, rtrieu, nikola, rjmccall, dblaikie
Reviewed By: rjmccall
Subscribers: EricWF, lebedev.ri, thakis, Quuxplusone, cfe-commits
Differential Revision: https://reviews.llvm.org/D44883
llvm-svn: 329493
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
layout" rules.
The new rules say that a standard-layout struct has its first non-static
data member and all base classes at offset 0, and consider a class to
not be standard-layout if that would result in multiple subobjects of a
single type having the same address.
We track "is C++11 standard-layout class" separately from "is
standard-layout class" so that the ABIs that need this information can
still use it.
Differential Revision: https://reviews.llvm.org/D45176
llvm-svn: 329332
Summary:
https://reviews.llvm.org/rL325291 implemented Coroutines TS N4723
section [dcl.fct.def.coroutine]/7, but it performed lookup of allocator
functions within both the global and class scope, whereas the specified
behavior is to perform lookup for custom allocators within just the
class scope.
To fix, add parameters to the `Sema::FindAllocationFunctions` function
such that it can be used to lookup allocators in global scope,
class scope, or both (instead of just being able to look up in just global
scope or in both global and class scope). Then, use those parameters
from within the coroutine Sema.
This incorrect behavior had the unfortunate side-effect of causing the
bug https://bugs.llvm.org/show_bug.cgi?id=36578 (or at least the reports
of that bug in C++ programs). That bug would occur for any C++ user with
a coroutine frame that took a single pointer argument, since it would
then find the global placement form `operator new`, described in the
C++ standard 18.6.1.3.1. This patch prevents Clang from generating code
that triggers the LLVM assert described in that bug report.
Test Plan: `check-clang`
Reviewers: GorNishanov, eric_niebler, lewissbaker
Reviewed By: GorNishanov
Subscribers: EricWF, cfe-commits
Differential Revision: https://reviews.llvm.org/D44552
llvm-svn: 328949
The diagnostic system for Clang can already handle many AST nodes. Instead
of converting them to strings first, just hand the AST node directly to
the diagnostic system and let it handle the output. Minor changes in some
diagnostic output.
llvm-svn: 328688
When SemaCoroutine looks for await_resume, it means it. No need for helpful: "Did you mean await_ready?" messages.
Fixes PR33477 and a couple of FIXMEs in test/SemaCXX/coroutines.cpp
llvm-svn: 328663
Summary:
Currently an invalid source range is generated for the member call expressions of `co_await`. The end location of the call expression is the `co_await` token loc, while the start is the location of the operand. This causes crashes when the source range is used to produce diagnostics.
This patch fixes the issues by using the expression location instead of the token location when building the member calls.
Reviewers: GorNishanov, rsmith, vsk, aaron.ballman
Reviewed By: vsk
Subscribers: cfe-commits, modocache
Differential Revision: https://reviews.llvm.org/D44915
llvm-svn: 328606
Previously, anytime the result of the resume expression in
operator co_await was unused, a warning was generated. This
patch fixes the issue by only generating the unused result warning
if calling `await_resume()` would also generate a warning.
llvm-svn: 328602
Summary: Rewrites -Winfinite-recursion to remove the state dictionary and explore paths in loops - especially infinite loops. The new check now detects recursion in loop bodies dominated by a recursive call.
Reviewers: rsmith, rtrieu
Reviewed By: rtrieu
Subscribers: lebedev.ri, cfe-commits
Differential Revision: https://reviews.llvm.org/D43737
llvm-svn: 328173
Summary:
Libc++'s default allocator uses `__builtin_operator_new` and `__builtin_operator_delete` in order to allow the calls to new/delete to be ellided. However, libc++ now needs to support over-aligned types in the default allocator. In order to support this without disabling the existing optimization Clang needs to support calling the aligned new overloads from the builtins.
See llvm.org/PR22634 for more information about the libc++ bug.
This patch changes `__builtin_operator_new`/`__builtin_operator_delete` to call any usual `operator new`/`operator delete` function. It does this by performing overload resolution with the arguments passed to the builtin to determine which allocation function to call. If the selected function is not a usual allocation function a diagnostic is issued.
One open issue is if the `align_val_t` overloads should be considered "usual" when `LangOpts::AlignedAllocation` is disabled.
In order to allow libc++ to detect this new behavior the value for `__has_builtin(__builtin_operator_new)` has been updated to `201802`.
Reviewers: rsmith, majnemer, aaron.ballman, erik.pilkington, bogner, ahatanak
Reviewed By: rsmith
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D43047
llvm-svn: 328134
More generally, this permits a template to be specialized in any scope in which
it could be defined, so this also supersedes DR44 and DR374 (the latter of
which we previously only implemented in C++11 mode onwards due to unclarity as
to whether it was a DR).
llvm-svn: 327705
r327343 changed the handling for CallExpr in a CFG, which prevented lookups for
CallExpr while other Stmt kinds still worked. This change carries over the
necessary bits from Stmt function to CallExpr function.
llvm-svn: 327593
Summary:
Let's suppose the `-Weverything` is passed.
Given code like
```
void F() {}
;
```
If the code is compiled with `-std=c++03`, it would diagnose that extra sema:
```
<source>:2:1: warning: extra ';' outside of a function is a C++11 extension [-Wc++11-extra-semi]
;
^~
```
If the code is compiled with `-std=c++11`, it also would diagnose that extra sema:
```
<source>:2:1: warning: extra ';' outside of a function is incompatible with C++98 [-Wc++98-compat-pedantic]
;
^~
```
But, let's suppose the C++11 or higher is used, and the used does not care
about `-Wc++98-compat-pedantic`, so he disables that diagnostic.
And that silences the complaint about extra `;` too.
And there is no way to re-enable that particular diagnostic, passing `-Wextra-semi` does nothing...
Now, there is also a related `no newline at end of file` diagnostic, which is also emitted by `-Wc++98-compat-pedantic`
```
<source>:2:2: warning: C++98 requires newline at end of file [-Wc++98-compat-pedantic]
;
^
```
But unlike the previous case, if `-Wno-c++98-compat-pedantic` is passed, that diagnostic stays displayed:
```
<source>:2:2: warning: no newline at end of file [-Wnewline-eof]
;
^
```
This diff refactors the code so `-Wc++98-compat-extra-semi` can be re-enabled, after the `-Wc++98-compat-pedantic` was disabled.
This seems ugly, but there does not seem to be any saner way.
Testing: `$ ninja check-clang`
Reviewers: rsmith, rtrieu, aaron.ballman
Reviewed By: aaron.ballman
Subscribers: jordan_rose, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D43162
llvm-svn: 327558
Summary:
This is PR36536.
There are a few ways to reach Sema::ActOnStartOfFunctionDef with a null
Decl. Currently, the parser continues on to attempt to parse the
statements in the function body without pushing a function scope or
declaration context. However, lots of statement parsing logic relies on
getCurFunction() returning something reasonable. It turns out that
getCurFunction() will never return null today because of an optimization
where Sema pre-allocates one FunctionScopeInfo and reuses it when
possible. This goes wrong when something inside the function body causes
us to push another function scope, such as requiring an implicit
definition of a special member function. Reusing the state clears it
out, which will lead to bugs. In PR36536, we found that the SwitchStack
gets unbalanced, because we push a switch, clear out the stack, and then
try to pop a switch that isn't there.
As a follow-up, I plan to move the pre-allocated FunctionScopeInfo out
of the FunctionScopes stack. This means the FunctionScopes stack will
often be empty, and callers of getCurFunction() will need to check for
null.
Reviewers: thakis
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D43980
llvm-svn: 326926
Current implementation of `FunctionDecl::isDefined` does not take into
account redeclarations that do not have bodies, but the bodies can be
instantiated from corresponding templated definition. This behavior does
not allow to detect function redefinition in the cases where friend
functions is defined in class templates. For instance, the code:
```
template<typename T> struct X { friend void f() {} };
X<int> xi;
void f() {}
```
compiles successfully but must fail due to redefinition of `f`. The
declaration of the friend `f` is created when the containing template
`X` is instantiated, but it does not have a body as per 14.5.4p4
because `f` is not odr-used.
With this change the function `Sema::CheckForFunctionRedefinition`
considers functions with uninstantiated bodies as definitions.
Differential Revision: https://reviews.llvm.org/D30170
llvm-svn: 326419
When indirect field is initialized with another field, you have
MemberExpr with CXXThisExpr that corresponds to the field's immediate
anonymous parent. But 'this' was referring to the non-anonymous parent.
So when we were building LValue Designator, it was incorrect as it had
wrong starting point. Usage of such designator would cause unexpected
APValue changes and crashes.
The fix is in adjusting 'this' for indirect fields from non-anonymous
parent to the field's immediate parent.
Discovered by OSS-Fuzz:
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=4985
rdar://problem/36359187
Reviewers: rsmith, efriedma
Reviewed By: rsmith
Subscribers: cfe-commits, jkorous-apple
Differential Revision: https://reviews.llvm.org/D42498
llvm-svn: 325997
The tests that failed on a windows host have been fixed.
Original message:
Start setting dso_local for COFF.
With this there are still some GVs where we don't set dso_local
because setGVProperties is never called. I intend to fix that in
followup commits. This is just the bare minimum to teach
shouldAssumeDSOLocal what it should do for COFF.
llvm-svn: 325940
expressions, if their lifetime began during the evaluation of the expression.
This is technically not allowed in C++11, though we could consider permitting
it there too, as an extension.
llvm-svn: 325663
Reimplement the "noexcept function actually throws" warning to properly handle
nested try-blocks. In passing, change 'throw;' handling to treat any enclosing
try block as being sufficient to suppress the warning rather than requiring a
'catch (...)'; the warning is intended to be conservatively-correct.
llvm-svn: 325545
There were a few issues previously with the target
attribute diagnostics implementation that lead to the
attribute being added to the AST despite having an error
in it.
This patch changes that, and adds a test to ensure it
does not get added to the AST.
Differential Revision: https://reviews.llvm.org/D43359
llvm-svn: 325364
Summary:
Fix a test failure on ARM hosts that was caused by a difference in the type of
size_t, by using a target-agnostic definiton.
Test Plan:
```
clang -cc1 -internal-isystem build/lib/clang/7.0.0/include -nostdsysteminc \
-std=c++14 -fcoroutines-ts -verify clang/test/SemaCXX/coroutines.cpp \
-fcxx-exceptions -fexceptions \
-triple armeb-none-eabi
```
llvm-svn: 325342
This broke the Chromium build, see https://crbug.com/813017
> accessibility of a class member.
>
> This fixes PR32898.
>
> rdar://problem/33737747
>
> Differential revision: https://reviews.llvm.org/D36918
llvm-svn: 325335
Summary:
Depends on https://reviews.llvm.org/D42605.
An implementation of the behavior described in `[dcl.fct.def.coroutine]/7`:
when a promise type overloads `operator new` using a "placement new"
that takes the same argument types as the coroutine function, that
overload is used when allocating the coroutine frame.
Simply passing references to the coroutine function parameters directly
to `operator new` results in invariant violations in LLVM's coroutine
splitting pass, so this implementation modifies Clang codegen to
produce allocator-specific alloc/store/loads for each parameter being
forwarded to the allocator.
Test Plan: `check-clang`
Reviewers: rsmith, GorNishanov, eric_niebler
Reviewed By: GorNishanov
Subscribers: lewissbaker, EricWF, cfe-commits
Differential Revision: https://reviews.llvm.org/D42606
llvm-svn: 325291
This patch fixes clang to not consider braced initializers for
aggregate elements of arrays to be potentially dependent on the
indices of the initialized elements. Resolves bug 18978:
initialize a large static array = clang oom?
https://bugs.llvm.org/show_bug.cgi?id=18978
Differential Revision: https://reviews.llvm.org/D43187
llvm-svn: 325120
When we synthesize an implicit inner initializer list when analyzing an outer
initializer list, we add it to the outer list immediately, and then fill in the
inner list. This gives the outer list no chance to update its *-dependence bits
with those of the completed inner list. To fix this, re-add the inner list to
the outer list once it's completed.
Note that we do not recompute the *-dependence bits from scratch when we
complete an outer list; this would give the wrong result for the case where a
designated initializer overwrites a dependent initializer with a non-dependent
one. The resulting list in that case should still be dependent, even though all
traces of the dependence were removed from the semantic form.
llvm-svn: 324537
Summary:
Clang incorrectly reports empty unions as having a unique object representation. However, this is not correct since `sizeof(EmptyUnion) == 1` AKA it has 8 bits of padding. Therefore it should be treated the same as an empty struct and report `false`.
@erichkeane also suggested this fix should be merged into the 6.0 release branch, so the initial release of `__has_unique_object_representations` is as bug-free as possible.
Reviewers: erichkeane, rsmith, aaron.ballman, majnemer
Reviewed By: erichkeane
Subscribers: cfe-commits, erichkeane
Differential Revision: https://reviews.llvm.org/D42863
llvm-svn: 324134
Summary:
Use corutine function arguments to initialize a promise type, but only
if the promise type defines a constructor that takes those arguments.
Otherwise, fall back to the default constructor.
Test Plan: check-clang
Reviewers: rsmith, GorNishanov, eric_niebler
Reviewed By: GorNishanov
Subscribers: toby-allsopp, lewissbaker, EricWF, cfe-commits
Differential Revision: https://reviews.llvm.org/D41820
llvm-svn: 323381
Both are related to handling anonymous structures.
* clang didn't handle () around an anonymous struct variable.
* clang also crashed on syntax errors that could lead to other
syntactic constructs following the declaration of an
anonymous struct. While the code is invalid, that's not
a good reason to panic compiler.
Differential Revision: https://reviews.llvm.org/D41788
llvm-svn: 322742
When parsing C++ type construction expressions with list initialization,
forward the locations of the braces to Sema.
Without these locations, the code coverage pass crashes on the given test
case, because the pass relies on getLocEnd() returning a valid location.
Here is what this patch does in more detail:
- Forwards init-list brace locations to Sema (ParseExprCXX),
- Builds an InitializationKind with these locations (SemaExprCXX), and
- Uses these locations for constructor initialization (SemaInit).
The remaining changes fall out of introducing a new overload for
creating direct-list InitializationKinds.
Testing: check-clang, and a stage2 coverage-enabled build of clang with
asserts enabled.
Differential Revision: https://reviews.llvm.org/D41921
llvm-svn: 322729
We were trying to emit a diag::err_bad_multiversion_option diagnostic,
which expects an int as its first argument, with a string argument. As
it happens, the string `Feature` that was causing this was shadowing an
int `Feature` from the surrounding scope. :)
llvm-svn: 322530
While here, fix up the myriad other ways in which Sema's two "can this handler
catch that exception?" implementations get things wrong and unify them.
llvm-svn: 322431
Summary:
The STL types `std::pair` and `std::tuple` can both store reference types. However their constructors cannot adequately check if the initialization of reference types is safe. For example:
```
std::tuple<std::tuple<int> const&> t = 42;
// The stored reference is already dangling.
```
Libc++ has a best effort attempts in tuple to diagnose this, but they're not able to handle all valid cases (If I'm not mistaken). For example initialization of a reference from the result of a class's conversion operator. Libc++ would benefit from having a builtin traits which can provide a much better implementation.
This patch introduce the `__reference_binds_to_temporary(T, U)` trait that determines whether a reference of type `T` bound to an expression of type `U` would bind to a materialized temporary object.
Note that the trait simply returns false if `T` is not a reference type instead of reporting it as an error.
```
static_assert(__is_constructible(int const&, long));
static_assert(__reference_binds_to_temporary(int const&, long));
```
Reviewers: majnemer, rsmith
Reviewed By: rsmith
Subscribers: compnerd, cfe-commits
Differential Revision: https://reviews.llvm.org/D29930
llvm-svn: 322334
In C++17, guaranteed copy elision means that there isn't necessarily a
constructor call when a local variable is initialized by a function call that
returns a scoped_lockable by value. In order to model the effects of
initializing a local variable with a function call returning a scoped_lockable,
pretend that the move constructor was invoked within the caller at the point of
return.
llvm-svn: 322316
GCC's attribute 'target', in addition to being an optimization hint,
also allows function multiversioning. We currently have the former
implemented, this is the latter's implementation.
This works by enabling functions with the same name/signature to coexist,
so that they can all be emitted. Multiversion state is stored in the
FunctionDecl itself, and SemaDecl manages the definitions.
Note that it ends up having to permit redefinition of functions so
that they can all be emitted. Additionally, all versions of the function
must be emitted, so this also manages that.
Note that this includes some additional rules that GCC does not, since
defining something as a MultiVersion function after a usage has been made illegal.
The only 'history rewriting' that happens is if a function is emitted before
it has been converted to a multiversion'ed function, at which point its name
needs to be changed.
Function templates and virtual functions are NOT yet supported (not supported
in GCC either).
Additionally, constructors/destructors are disallowed, but the former is
planned.
llvm-svn: 322028
Check whether we are comparing the same entity, not merely the same
declaration, and don't assume that weak declarations resolve to distinct
entities.
llvm-svn: 321976
during template argument deduction.
We already did this when the injected-class-name was in P, but missed the case
where it was in A. This (probably) can't happen except in implicit deduction
guides.
llvm-svn: 321779
Summary:
The diagnostic was mostly introduced in D38101 by me, as a reaction to wasting a lot of time, see [[ https://lists.llvm.org/pipermail/cfe-commits/Week-of-Mon-20171009/206427.html | mail ]].
However, the diagnostic is pretty dumb. While it works with no false-positives,
there are some questionable cases that are diagnosed when one would argue that they should not be.
The common complaint is that it diagnoses the comparisons between an `int` and
`long` when compiling for a 32-bit target as tautological, but not when
compiling for 64-bit targets. The underlying problem is obvious: data model.
In most cases, 64-bit target is `LP64` (`int` is 32-bit, `long` and pointer are
64-bit), and the 32-bit target is `ILP32` (`int`, `long`, and pointer are 32-bit).
I.e. the common pattern is: (pseudocode)
```
#include <limits>
#include <cstdint>
int main() {
using T1 = long;
using T2 = int;
T1 r;
if (r < std::numeric_limits<T2>::min()) {}
if (r > std::numeric_limits<T2>::max()) {}
}
```
As an example, D39149 was trying to fix this diagnostic in libc++, and it was not well-received.
This *could* be "fixed", by changing the diagnostics logic to something like
`if the types of the values being compared are different, but are of the same size, then do diagnose`,
and i even attempted to do so in D39462, but as @rjmccall rightfully commented,
that implementation is incomplete to say the least.
So to stop causing trouble, and avoid contaminating upcoming release, lets do this workaround:
* move these three diags (`warn_unsigned_always_true_comparison`, `warn_unsigned_enum_always_true_comparison`, `warn_tautological_constant_compare`) into it's own `-Wtautological-constant-in-range-compare`
* Disable them by default
* Make them part of `-Wextra`
* Additionally, give `warn_tautological_constant_compare` it's own flag `-Wtautological-type-limit-compare`.
I'm not happy about that name, but i can't come up with anything better.
This way all three of them can be enabled/disabled either altogether, or one-by-one.
Reviewers: aaron.ballman, rsmith, smeenai, rjmccall, rnk, mclow.lists, dim
Reviewed By: aaron.ballman, rsmith, dim
Subscribers: thakis, compnerd, mehdi_amini, dim, hans, cfe-commits, rjmccall
Tags: #clang
Differential Revision: https://reviews.llvm.org/D41512
llvm-svn: 321691
Previously, we would:
* compute the type of the conversion function and static invoker as a
side-effect of template argument deduction for a conversion
* re-compute the type as part of deduced return type deduction when building
the conversion function itself
Neither of these turns out to be quite correct. There are other ways to reach a
declaration of the conversion function than in a conversion (such as an
explicit call or friend declaration), and performing auto deduction causes the
function type to be rebuilt in the context of the lambda closure type (which is
different from the context in which it originally appeared, resulting in
spurious substitution failures for constructs that are valid in one context but
not the other, such as the use of an enclosing class's "this" pointer).
This patch switches us to use a different strategy: as before, we use the
declared type of the operator() to form the type of the conversion function and
invoker, but we now populate that type as part of return type deduction for the
conversion function. And the invoker is now treated as simply being an
implementation detail of building the conversion function, and isn't given
special treatment by template argument deduction for the conversion function
any more.
llvm-svn: 321683
(Re-submission of D39937 with fixed tests.)
Adjust wording for const-qualification mismatch to be a little more clear.
Also add another diagnostic for a ref qualifier mismatch, which previously produced a useless error (this error path is simply very old; see rL119336):
Before:
error: cannot initialize object parameter of type 'X0' with an expression of type 'X0'
After:
error: 'this' argument to member function 'rvalue' is an lvalue, but function has rvalue ref-qualifier
Reviewers: aaron.ballman
Reviewed By: aaron.ballman
Subscribers: lebedev.ri, cfe-commits
Differential Revision: https://reviews.llvm.org/D41646
llvm-svn: 321609
Summary:
Adjust wording for const-qualification mismatch to be a little more clear.
Also add another diagnostic for a ref qualifier mismatch, which previously produced a useless error (this error path is simply very old; see rL119336):
Before:
error: cannot initialize object parameter of type 'X0' with an expression of type 'X0'
After:
error: 'this' argument to member function 'rvalue' is an lvalue, but function has rvalue ref-qualifier
Reviewers: rsmith, aaron.ballman
Reviewed By: aaron.ballman
Subscribers: lebedev.ri, aaron.ballman, cfe-commits
Differential Revision: https://reviews.llvm.org/D39937
llvm-svn: 321592
This is a slightly odd construct (it's more common to see "A (::B)()") but can
happen in friend declarations, and the parens are not redundant as they prevent
the :: binding to the left.
llvm-svn: 321318
An unscoped enumeration used as template argument, should not have any
qualified information about its enclosing scope, as its visibility is
global.
In the case of scoped enumerations, they must include information
about their enclosing scope.
Patch by Carlos Alberto Enciso!
Differential Revision: https://reviews.llvm.org/D39239
llvm-svn: 321312
This allows you to dump C++ code that spells bool instead of _Bool, leaves off the elaborated type specifiers when printing struct or class names, and other C-isms.
Fixes the -Wreorder issue and fixes the ast-dump-color.cpp test.
llvm-svn: 321310
This allows you to dump C++ code that spells bool instead of _Bool, leaves off the elaborated type specifiers when printing struct or class names, and other C-isms.
llvm-svn: 321223
The initializeLocal function of UnaryTransformTypeLoc missed
the UnderlyingTInfo member. This caused a null-dereference
issue, as reported in PR23421. This patch correctly initializss
the UnderlyingTInfo.
llvm-svn: 320765
Summary:
In D41064, I proposed adding `#pragma clang diagnostic ignored
"-Wuser-defined-literals"` to some of libc++'s headers, since these
warnings are now triggered by clang's new `-std=gnu++14` default:
```
$ cat test.cpp
#include <string>
$ clang -std=c++14 -Wsystem-headers -Wall -Wextra -c test.cpp
In file included from test.cpp:1:
In file included from /usr/include/c++/v1/string:470:
/usr/include/c++/v1/string_view:763:29: warning: user-defined literal suffixes not starting with '_' are reserved [-Wuser-defined-literals]
basic_string_view<char> operator "" sv(const char *__str, size_t __len)
^
/usr/include/c++/v1/string_view:769:32: warning: user-defined literal suffixes not starting with '_' are reserved [-Wuser-defined-literals]
basic_string_view<wchar_t> operator "" sv(const wchar_t *__str, size_t __len)
^
/usr/include/c++/v1/string_view:775:33: warning: user-defined literal suffixes not starting with '_' are reserved [-Wuser-defined-literals]
basic_string_view<char16_t> operator "" sv(const char16_t *__str, size_t __len)
^
/usr/include/c++/v1/string_view:781:33: warning: user-defined literal suffixes not starting with '_' are reserved [-Wuser-defined-literals]
basic_string_view<char32_t> operator "" sv(const char32_t *__str, size_t __len)
^
In file included from test.cpp:1:
/usr/include/c++/v1/string:4012:24: warning: user-defined literal suffixes not starting with '_' are reserved [-Wuser-defined-literals]
basic_string<char> operator "" s( const char *__str, size_t __len )
^
/usr/include/c++/v1/string:4018:27: warning: user-defined literal suffixes not starting with '_' are reserved [-Wuser-defined-literals]
basic_string<wchar_t> operator "" s( const wchar_t *__str, size_t __len )
^
/usr/include/c++/v1/string:4024:28: warning: user-defined literal suffixes not starting with '_' are reserved [-Wuser-defined-literals]
basic_string<char16_t> operator "" s( const char16_t *__str, size_t __len )
^
/usr/include/c++/v1/string:4030:28: warning: user-defined literal suffixes not starting with '_' are reserved [-Wuser-defined-literals]
basic_string<char32_t> operator "" s( const char32_t *__str, size_t __len )
^
8 warnings generated.
```
Both @aaron.ballman and @mclow.lists felt that adding this workaround to
the libc++ headers was the wrong way, and it should be fixed in clang
instead.
Here is a proposal to do just that. I verified that this suppresses the
warning, even when -Wsystem-headers is used, and that the warning is
still emitted for a declaration outside of system headers.
Reviewers: aaron.ballman, mclow.lists, rsmith
Reviewed By: aaron.ballman
Subscribers: mclow.lists, aaron.ballman, andrew, emaste, cfe-commits
Differential Revision: https://reviews.llvm.org/D41080
llvm-svn: 320755
There are many more expr types that can be a capability expr, like
CXXThisExpr, CallExpr, MemberExpr. Instead of enumerating all of them,
just check typeHasCapability for any type given.
Also add & and * operators to allowed unary operators.
Differential Revision: https://reviews.llvm.org/D41224
llvm-svn: 320753
Adding the new enumerator forced a bunch more changes into this patch than I
would have liked. The -Wtautological-compare warning was extended to properly
check the new comparison operator, clang-format needed updating because it uses
precedence levels as weights for determining where to break lines (and several
operators increased their precedence levels with this change), thread-safety
analysis needed changes to build its own IL properly for the new operator.
All "real" semantic checking for this operator has been deferred to a future
patch. For now, we use the relational comparison rules and arbitrarily give
the builtin form of the operator a return type of 'void'.
llvm-svn: 320707
The two asserts are too aggressive. In C++ mode, an
enum is NOT considered an integral type, but an enum value
is allowed to be an enum. This patch relaxes the two asserts
to allow the enum value as well (as typechecking does).
llvm-svn: 320411
Summary:
This is a side-effect brought in by p0620r0, which allows other placeholder types (derived from `auto` and `decltype(auto)`) to be usable in a `new` expression with a single-clause //braced-init-list// as its initializer (8.3.4 [expr.new]/2). N3922 defined its semantics.
References:
http://wg21.link/p0620r0http://wg21.link/n3922
Reviewers: rsmith, aaron.ballman
Reviewed By: rsmith
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D39451
llvm-svn: 320401
Summary:
Clang was crashing when diagnosing an unused-lambda-capture for a VLA because
From.getVariable() is null for the capture of a VLA bound.
Warning about the VLA bound capture is not helpful, so only warn for the VLA
itself.
Fixes: PR35555
Reviewers: aaron.ballman, dim, rsmith
Reviewed By: aaron.ballman, dim
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D41016
llvm-svn: 320396
and fold together into a single function.
In so doing, fix a handful of remaining bugs where we would report false
positives or false negatives if we promote a signed value to an unsigned type
for the comparison.
This re-commits r320122 and r320124, minus two changes:
* Comparisons between a constant and a non-constant expression of enumeration
type never warn, not even if the constant is out of range. We should be
warning about the creation of such a constant, not about its use.
* We do not use more precise bit-widths for comparisons against bit-fields.
The more precise diagnostics probably are the right thing, but we should
consider moving them under their own warning flag.
Other than the refactoring, this patch should only change the behavior for the
buggy cases (where the warnings didn't take into account that promotion from
signed to unsigned can leave a range of inaccessible values in the middle of
the promoted type).
llvm-svn: 320211
> Unify implementation of our two different flavours of -Wtautological-compare.
>
> In so doing, fix a handful of remaining bugs where we would report false
> positives or false negatives if we promote a signed value to an unsigned type
> for the comparison.
This caused a new warning in Chromium:
../../base/trace_event/trace_log.cc:1545:29: error: comparison of constant 64
with expression of type 'unsigned int' is always true
[-Werror,-Wtautological-constant-out-of-range-compare]
DCHECK(handle.event_index < TraceBufferChunk::kTraceBufferChunkSize);
~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The 'unsigned int' is really a 6-bit bitfield, which is why it's always
less than 64.
I thought we didn't use to warn (with out-of-range-compare) when comparing
against the boundaries of a type?
llvm-svn: 320162
In so doing, fix a handful of remaining bugs where we would report false
positives or false negatives if we promote a signed value to an unsigned type
for the comparison.
llvm-svn: 320122
This is a fix for PR35509 in which we crash because we attempt to compute the
alignment of an incomplete type.
Differential Revision: https://reviews.llvm.org/D40895
llvm-svn: 320017
Summary:
This feature was discussed but not yet proposed. It allows a structured binding to appear as a //condition//
if (auto [ok, val] = f(...))
So the user can save an extra //condition// if the statement can test the value to-be-decomposed instead. Formally, it makes the value of the underlying object of the structured binding declaration also the value of a //condition// that is an initialized declaration.
Considering its logicality which is entirely evident from its trivial implementation, I think it might be acceptable to land it as an extension for now before I write the paper.
Reviewers: rsmith, faisalv, aaron.ballman
Reviewed By: rsmith
Subscribers: aaron.ballman, cfe-commits
Differential Revision: https://reviews.llvm.org/D39284
llvm-svn: 320011
As rsmith pointed out, the original implementation of this intrinsic
missed a number of important situations. This patch fixe a bunch of
shortcomings and implementation details to make it work correctly.
Differential Revision: https://reviews.llvm.org/D39347
llvm-svn: 319446
Sometimes we check the validity of some construct between producing a
diagnostic and producing its notes. Ideally, we wouldn't do that, but in
practice running code that "cannot possibly produce a diagnostic" in such a
situation should be safe, and reasonable factoring of some code requires it
with our current diagnostics infrastruture. If this does happen, a diagnostic
that's suppressed due to SFINAE should not cause notes connected to the prior
diagnostic to be suppressed.
llvm-svn: 319408
This also clarifies some terminology used by the diagnostic (methods -> Objective-C methods, fields -> non-static data members, etc).
Many of the tests needed to be updated in multiple places for the diagnostic wording tweaks. The first instance of the diagnostic for that attribute is fully specified and subsequent instances cut off the complete list (to make it easier if additional subjects are added in the future for the attribute).
llvm-svn: 319002
This implements [dcl.modules.export] from the C++ Modules TS, which lets a module re-export another module with the "export import" syntax.
Differential Revision: https://reviews.llvm.org/D40270
llvm-svn: 318744
This caused warnings also when the if or else comes from macros. There was an
attempt to fix this in r318556, but that introduced new problems and was
reverted. Reverting this too until the whole issue is sorted.
> This looks like it was just an oversight.
>
> Fixes http://llvm.org/pr35319
>
> git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@318456 91177308-0d34-0410-b5e6-96231b3b80d8
llvm-svn: 318667
It seems this somehow made -Wempty-body fire in some macro cases where
it didn't before, e.g.
../../third_party/ffmpeg/libavcodec/bitstream.c(169,5): error: if statement has empty body [-Werror,-Wempty-body]
ff_dlog(NULL, "new table index=%d size=%d\n", table_index, table_size);
^
../../third_party/ffmpeg\libavutil/internal.h(276,80): note: expanded from macro 'ff_dlog'
# define ff_dlog(ctx, ...) do { if (0) av_log(ctx, AV_LOG_DEBUG, __VA_ARGS__); } while (0)
^
../../third_party/ffmpeg/libavcodec/bitstream.c(169,5): note: put the
semicolon on a separate line to silence this warning
Reverting until this can be figured out.
> Do not show it when `if` or `else` come from macros.
> E.g.,
>
> #define USED(A) if (A); else
> #define SOME_IF(A) if (A)
>
> void test() {
> // No warnings are shown in those cases now.
> USED(0);
> SOME_IF(0);
> }
>
> Patch by Ilya Biryukov!
>
> Differential Revision: https://reviews.llvm.org/D40185
llvm-svn: 318665
Do not show it when `if` or `else` come from macros.
E.g.,
#define USED(A) if (A); else
#define SOME_IF(A) if (A)
void test() {
// No warnings are shown in those cases now.
USED(0);
SOME_IF(0);
}
Patch by Ilya Biryukov!
Differential Revision: https://reviews.llvm.org/D40185
llvm-svn: 318556
In the PR, Clang ended up in a situation where it tried to mangle the
__float128 type, which isn't supported when targetingt MSVC, because
Clang instantiated a variable template with that type when searching for
a conversion to use in an arithmetic expression.
Differential revision: https://reviews.llvm.org/D39579
llvm-svn: 318309
From http://reviews.llvm.org/D4368 these cases were thought to not be reachable
and the checks removed before the rest of the code was committed in r216649.
However, these cases are reachable and the checks are added back.
llvm-svn: 317957
Given a choice between a constructor call and a conversion function in C++17,
we prefer the constructor for direct-initialization and the conversion function
for copy-initialization, matching the behavior in C++14 and before. The
guaranteed copy elision rules were not intended to change the meaning of such
code (other than by removing unnecessary copy constructor calls).
This tweak will be raised with CWG.
llvm-svn: 317066
Summary:
Clang typically warns that in the following class hierarchy, 'A' is
inaccessible because there is no series of casts that the user can
write to access it unambiguously:
struct A { };
struct B : A { };
struct C : A, B { };
MSVC allows the user to convert from C* to A*, though, and we've
encountered this issue in the latest Windows SDK headers.
This patch allows this conversion when -fms-compatibility is set and
adds a warning for it under -Wmicrosoft-inaccessible-base.
Reviewers: rsmith
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D39389
llvm-svn: 316807
Summary:
The warning was initially introduced in D32914 by @thakis,
and the concerns were raised there, and later in rL302247
and PR33771.
I do believe that it makes sense to relax the diagnostic
e.g. in this case, when the expression originates from the
system header, which can not be modified. This prevents
adoption for the diagnostic for codebases which use pthreads
(`PTHREAD_MUTEX_INITIALIZER`), gtest, etc.
As @malcolm.parsons suggests, it *may* make sense to also
not warn for the template types, but it is not obvious to
me how to do that in here.
Though, it still makes sense to complain about `NULL` macro.
While there, add more tests.
Reviewers: dblaikie, thakis, rsmith, rjmccall, aaron.ballman
Reviewed By: thakis
Subscribers: Rakete1111, hans, cfe-commits, thakis, malcolm.parsons
Tags: #clang
Differential Revision: https://reviews.llvm.org/D38954
llvm-svn: 316662
Martin Storsjo