objc_loadWeak. This retains and autorelease the weakly-refereced
object. This hidden autorelease sometimes makes __weak variable alive even
after the weak reference is erased, because the object is still referenced
by an autorelease pool. This patch overcomes this behavior by loading a
weak object via call to objc_loadWeakRetained(), followng it by objc_release
at appropriate place, thereby removing the hidden autorelease. // rdar://10849570
llvm-svn: 168740
Separate out the notions of 'has a trivial special member' and 'has a
non-trivial special member', and use them appropriately. These are not
opposites of one another (there might be no special member, or in C++11 there
might be a trivial one and a non-trivial one). The CXXRecordDecl predicates
continue to produce incorrect results, but do so in fewer cases now, and
they document the cases where they might be wrong.
No functionality changes are intended here (they will come when the predicates
start producing the right answers...).
llvm-svn: 168119
BinaryOperator::Opcode. This is bad form, and the behavior of the static_cast
in this case is unspecified according to the standard.
Fixes a warning that showed up from r167992 on self-host.
llvm-svn: 168010
positions of Objective-C methods.
It is possible to recover a lot of type information about
Objective-C methods from the reflective metadata for their
implementations. This information is not rich when it
comes to struct types, however, and it is not possible to
produce a type in the debugger's round-tripped AST which
will really do anything useful during type-checking.
Therefore we allow __unknown_anytype in these positions,
which essentially disables type-checking for that argument.
We infer the parameter type to be the unqualified type of
the argument expression unless that expression is an
explicit cast, in which case it becomes the type-as-written
of that cast.
rdar://problem/12565338
llvm-svn: 167896
This warning was failing to fire under ARC because of the implicit
lifetime casts added around the object literal expression.
<rdar://problem/11300873>, again.
llvm-svn: 167648
instantiate it if it can be instantiated and implicitly define it if it can be
implicitly defined. This matches g++'s approach. Remove some cases from
SemaOverload which were marking functions as referenced when just planning how
overload resolution would proceed; such cases are not actually references.
llvm-svn: 167514
found: if an overloaded operator& is present before a template definition,
the expression &T::foo is represented as a CXXOperatorCallExpr, not as a
UnaryOperator, so we didn't notice that it's permitted to reference a non-static
data member of an unrelated class.
While investigating this, I discovered another problem in this area: we are
treating template default arguments as unevaluated contexts during substitution,
resulting in performing incorrect checks for uses of non-static data members in
C++11. That is not fixed by this patch (I'll look into this soon; it's related
to the failure to correctly instantiate constexpr function templates), but was
resulting in this bug not firing in C++11 mode (except with -Wc++98-compat).
Original message:
PR14124: When performing template instantiation of a qualified-id outside of a
class, diagnose if the qualified-id instantiates to a non-static class member.
llvm-svn: 166385
initialized by a reference constant expression.
Our odr-use modeling still needs work here: we don't yet implement the 'set of
potential results of an expression' DR.
llvm-svn: 166361
When suggesting "foo::bar" as a correction for "fob::bar" we mistakenly
replaced only "bar" with "foo::bar" producing "fob::foo::bar" which was broken.
This corrects that replacement in as many places as I could find & provides
test cases for all those cases I could find a test case for. There are a couple
that don't seem to be reachable (one looks entirely dead, the other just
doesn't seem to ever get called with a namespace to namespace change).
Review by Richard Smith ( http://llvm-reviews.chandlerc.com/D57 ).
llvm-svn: 165817
This only applies if the type has a name. (we could potentially do something
crazy with decltype in C++11 to qualify members of unnamed types but that
seems excessive)
It might be nice to also suggest a fixit for "&this->i", "&foo->i",
and "&foo.i" but those expressions produce 'bound' member functions that have
a different AST representation & make error recovery a little trickier. Left
as future work.
llvm-svn: 165763
Then, switch users of PropertyIfSetterOrGetter and LookupPropertyDecl
(the latter by name) over to findPropertyDecl. This actually makes
-Wreceiver-is-weak a bit stronger than it was before.
llvm-svn: 165628
This appears to be consistent with GCC's implementation of the same warning
under -Wparentheses. Suppressing a << b + c for cases where 'a' is a user
defined type for compatibility with C++ stream IO. Otherwise suggest
parentheses around the addition or subtraction subexpression.
(this came up when MSVC was complaining (incorrectly, so far as I can tell)
about a perceived violation of this within the LLVM codebase, PR14001)
llvm-svn: 165283
Clang will now honor the FP_CONTRACT pragma and emit LLVM
fmuladd intrinsics for expressions of the form A * B + C (when they occur in a
single statement).
llvm-svn: 164989
Like properties, loading from a weak ivar twice in the same function can
give you inconsistent results if the object is deallocated between the
two loads. It is safer to assign to a strong local variable and use that.
Second half of <rdar://problem/12280249>.
llvm-svn: 164855
The motivating example:
if (self.weakProp)
use(self.weakProp);
As with any non-atomic test-then-use, it is possible a weak property to be
non-nil at the 'if', but be deallocated by the time it is used. The correct
way to write this example is as follows:
id tmp = self.weakProp;
if (tmp)
use(tmp);
The warning is controlled by -Warc-repeated-use-of-receiver, and uses the
property name and base to determine if the same property on the same object
is being accessed multiple times. In cases where the base is more
complicated than just a single Decl (e.g. 'foo.bar.weakProp'), it picks a
Decl for some degree of uniquing and reports the problem under a subflag,
-Warc-maybe-repeated-use-of-receiver. This gives a way to tune the
aggressiveness of the warning for a particular project.
The warning is not on by default because it is not flow-sensitive and thus
may have a higher-than-acceptable rate of false positives, though it is
less noisy than -Wreceiver-is-weak. On the other hand, it will not warn
about some cases that may be legitimate issues that -Wreceiver-is-weak
will catch, and it does not attempt to reason about methods returning weak
values.
Even though this is not a real "analysis-based" check I've put the bug
emission code in AnalysisBasedWarnings for two reasons: (1) to run on
every kind of code body (function, method, block, or lambda), and (2) to
suggest that it may be enhanced by flow-sensitive analysis in the future.
The second (smaller) half of this work is to extend it to weak locals
and weak ivars. This should use most of the same infrastructure.
Part of <rdar://problem/12280249>
llvm-svn: 164854
typeid (and a couple other non-standard places where we can transform an
unevaluated expression into an evaluated expression) is special
because it introduces an an expression evaluation context,
which conflicts with the mechanism to compute the current
lambda mangling context. PR12123.
I would appreciate if someone would double-check that we get the mangling
correct with this patch.
llvm-svn: 164658
Specifically, this should warn:
__block block_t a = ^{ a(); };
Furthermore, this case which previously warned now does not, since the value
of 'b' is captured before the assignment occurs:
block_t b; // not __block
b = ^{ b(); };
(This will of course warn under -Wuninitialized, as before.)
<rdar://problem/11015883>
llvm-svn: 163962
(__builtin_* etc.) so that it isn't possible to take their address.
Specifically, introduce a new type to represent a reference to a builtin
function, and a new cast kind to convert it to a function pointer in the
operand of a call. Fixes PR13195.
llvm-svn: 162962
__objc_yes/__objc_no to (BOOL)1/(BOOL)0 when
BOOL is declared; otherwise it resorts to
default of 'signed char'. This is important to
selecting the correct Numeric API numberWithBool:
Can't have a clang test for this. Will checkin and
executable llvm test. // rdar://12156616
llvm-svn: 162922
both a waste of time, and prone to crash due to the use of the
error-recovery path in parser. Fixes <rdar://problem/12103608>, which
has been driving me nuts.
llvm-svn: 162081
This is effectively a warning for code that violates core issue 903 & thus will
become standard error in the future, hopefully. It catches strange null
pointers such as: '\0', 1 - 1, const int null = 0; etc...
There's currently a flaw in this warning (& the warning for 'false' as a null
pointer literal as well) where it doesn't trigger on comparisons (ptr == '\0'
for example). Fix to come in a future patch.
Also, due to this only being a warning, not an error, it triggers quite
frequently on gtest code which tests expressions for null-pointer-ness in a
SFINAE context (so it wouldn't be a problem if this was an error as in an
actual implementation of core issue 903). To workaround this for now, the
diagnostic does not fire in unevaluated contexts.
Review by Sean Silva and Richard Smith.
llvm-svn: 161501
The one caller that's surrounded by nearby code manipulating the underlying
evaluation context list is left unmodified for readability.
Review by Sean Silva and Richard Smith.
llvm-svn: 161355
on object pointers and whether pointer arithmetic on object pointers
is supported. Make ObjFW interpret subscripts as pseudo-objects.
Based on a patch by Jonathan Schleifer.
llvm-svn: 161028
a defaulted special member function until the exception specification is needed
(using the same criteria used for the delayed instantiation of exception
specifications for function temploids).
EST_Delayed is now EST_Unevaluated (using 1330's terminology), and, like
EST_Uninstantiated, carries a pointer to the FunctionDecl which will be used to
resolve the exception specification.
This is enabled for all C++ modes: it's a little faster in the case where the
exception specification isn't used, allows our C++11-in-C++98 extensions to
work, and is still correct for C++98, since in that mode the computation of the
exception specification can't fail.
The diagnostics here aren't great (in particular, we should include implicit
evaluation of exception specifications for defaulted special members in the
template instantiation backtraces), but they're not much worse than before.
Our approach to the problem of cycles between in-class initializers and the
exception specification for a defaulted default constructor is modified a
little by this change -- we now reject any odr-use of a defaulted default
constructor if that constructor uses an in-class initializer and the use is in
an in-class initialzer which is declared lexically earlier. This is a closer
approximation to the current draft solution in core issue 1351, but isn't an
exact match (but the current draft wording isn't reasonable, so that's to be
expected).
llvm-svn: 160847
change once it's been assigned. It can change in two ways:
1) In a template instantiation, the context declaration should be the
instantiated declaration, not the declaration in the template.
2) If a lambda appears in the pattern of a variadic pack expansion, the
mangling number will depend on the pack length.
llvm-svn: 160614
While we still want to consider this a hard error (non-POD variadic args are
normally a DefaultError warning), delaying the diagnostic allows us to give
better error messages, which also match the usual non-POD errors more closely.
In addition, this change improves the diagnostic messages for format string
argument type mismatches by passing down the type of the callee, so we can
say "variadic method" or "variadic function" appropriately.
<rdar://problem/11825593>
llvm-svn: 160517
Checks against nil often appear as guards in macros, and comparing
Objective-C literals to nil has well-defined behavior (if tautological).
On OS X, 'nil' has not been typed as 'id' since 10.6 (possibly earlier),
so the warning was already not firing, but other runtimes continue to use
((id)0) or some variant. This change accepts comparisons to any null pointer;
to keep it simple, it looks through all casts (not just casts to 'id').
PR13276
llvm-svn: 160379
Suggested by Ted, since string literal comparison is at least slightly more
sensible than comparison of runtime literals. (Ambiguous language on
developer.apple.com implies that strings are guaranteed to be uniqued within
a translation unit and possibly across a linked binary.)
llvm-svn: 160378
Recovering as if the user had actually called -isEqual: is a bit too far from
the semantics of the program as written, /even though/ it's probably what they
intended.
llvm-svn: 160377
as an array of its base class TemplateArgument. Switch the const
TemplateArgument* parameters of InstantiatingTemplate's constructors to
ArrayRef<TemplateArgument> to prevent this from happening again in the future.
llvm-svn: 160245
Chris pointed out that while the comparison is certainly problematic
and does not have well-defined behavior, it isn't any worse than some
of the other abuses that we merely warn about and doesn't need to make
the compilation fail.
Revert the release notes change (r159766) now that this is just a new warning.
llvm-svn: 159939
-ftemplate-depth limit. There are various ways to get an infinite (or merely
huge) stack of substitutions with no intervening instantiations. This is also
consistent with gcc's behavior.
llvm-svn: 159907
In C, enum constants have the type of the enum's underlying integer type,
rather than the type of the enum. (This is not true in C++.) Thus, when a
block's return type is inferred from an enum constant, it is incompatible
with expressions that return the enum type.
In r158899, I told block returns to pretend that enum constants have enum
type, like in C++. Doug Gregor pointed out that this can break existing code.
Now, we don't check the types of return statements until the end of the block.
This lets us go back and add implicit casts in blocks with mixed enum
constants and enum-typed expressions.
<rdar://problem/11662489> (again)
llvm-svn: 159591
to see if we had an underlying final class or method, but we would then
use the cast type to do the call, resulting in a direct call to the wrong
method.
llvm-svn: 159212
resulted in it being reverted. A test for that bug was added in r158950.
Original comment:
If an object (such as a std::string) with an appropriate c_str() member function
is passed to a variadic function in a position where a format string indicates
that c_str()'s return type is desired, provide a note suggesting that the user
may have intended to call the c_str() member.
Factor the non-POD-vararg checking out of DefaultVariadicArgumentPromotion and
move it to SemaChecking in order to facilitate this. Factor the call checking
out of function call checking and block call checking, and extend it to cover
constructor calls too.
Patch by Sam Panzer!
llvm-svn: 159159
Heavily based on a patch from
Aaron Wishnick <aaron.s.wishnick@gmail.com>.
I'll clean up the duplicated function in CodeGen as
a follow-up, later today or tomorrow.
llvm-svn: 159060
Revert "If an object (such as a std::string) with an appropriate c_str() member function"
This reverts commit 7d96f6106bfbd85b1af06f34fdbf2834aad0e47e.
llvm-svn: 158949
Also, don't warn if the used function is __attribute__((const)), in which case
it's not supposed to use global variables anyway.
The inline-in-inline thing is a heuristic, and one that's possibly incorrect
fairly often because the function being inlined could definitely use global
variables. However, even some C standard library functions are written using
other (trivial) static-inline functions in the headers, and we definitely don't
want to be warning on that (or on anything that /uses/ these trivial inline
functions). So we're using "inlined" as a marker for "fairly trivial".
(Note that __attribute__((pure)) does /not/ guarantee safety like ((const),
because ((const)) does not guarantee that global variables are not being used,
and the warning is about globals not being shared across TUs.)
llvm-svn: 158898
is passed to a variadic function in a position where a format string indicates
that c_str()'s return type is desired, provide a note suggesting that the user
may have intended to call the c_str() member.
Factor the non-POD-vararg checking out of DefaultVariadicArgumentPromotion and
move it to SemaChecking in order to facilitate this. Factor the call checking
out of function call checking and block call checking, and extend it to cover
constructor calls too.
Patch by Sam Panzer!
llvm-svn: 158887
in microsoft mode. Fixes PR12701.
The code for this was already in 2 of the 3 branches of a
conditional and missing in the 3rd branch, so lift it above
the conditional.
llvm-svn: 158842
It's very easy for anonymous external linkage to propagate in C++ through
return types and parameter types. Likewise, it's possible that a template
containing an inline function is only used with parameters that have internal
linkage. Actually diagnosing where the internal linkage comes from is fairly
difficult (both to locate and then to print nicely). Finally, since we only
have one translation unit available, we can't even prove that any of this
violates the ODR.
This warning needs better-defined behavior in C++ before it can really go in.
Rewording of the C warning (which /is/ specified by C99) coming shortly.
llvm-svn: 158836
target Objective-C runtime down to the frontend: break this
down into a single target runtime kind and version, and compute
all the relevant information from that. This makes it
relatively painless to add support for new runtimes to the
compiler. Make the new -cc1 flag, -fobjc-runtime=blah-x.y.z,
available at the driver level as a better and more general
alternative to -fgnu-runtime and -fnext-runtime. This new
concept of an Objective-C runtime also encompasses what we
were previously separating out as the "Objective-C ABI", so
fragile vs. non-fragile runtimes are now really modelled as
different kinds of runtime, paving the way for better overall
differentiation.
As a sort of special case, continue to accept the -cc1 flag
-fobjc-runtime-has-weak, as a sop to PLCompatibilityWeak.
I won't go so far as to say "no functionality change", even
ignoring the new driver flag, but subtle changes in driver
semantics are almost certainly not intended.
llvm-svn: 158793
Per post-commit review, it's not appropriate to use ExtWarn in C++, because
we can't prove that the inline function will actually be defined in more than
one place (and thus we can't prove that this violates the ODR).
This removes the warning entirely from uses in the main source file in C++.
llvm-svn: 158689
This includes treating anonymous namespaces like internal linkage, and allowing
const variables to be used even if internal. The whole thing's been broken out
into a separate function to avoid nested ifs.
llvm-svn: 158683
This handles the very common case of people writing inline functions in their
main source files and not tagging them as inline. These cases should still
behave as the user intended. (The diagnostic is still emitted as an extension.)
I'm reworking this code anyway to account for C++'s equivalent restriction in
[basic.def.odr]p6, but this should get some bots back to green.
llvm-svn: 158666
This is explicitly forbidden in C99 6.7.4p3. This is /not/ forbidden in C++,
probably because by default file-scope const/constexpr variables have internal
linkage, while functions have external linkage. There's also the issue of
anonymous namespaces to consider. Nevertheless, there should probably be a
similar warning, since the semantics of inlining a function that references
a variable with internal linkage do not seem well-defined.
<rdar://problem/11577619>
llvm-svn: 158531
Objective-C literals conceptually always create new objects, but may be
optimized by the compiler or runtime (constant folding, singletons, etc).
Comparing addresses of these objects is relying on this optimization
behavior, which is really an implementation detail.
In the case of == and !=, offer a fixit to a call to -isEqual:, if the
method is available. This fixit is directly on the error so that it is
automatically applied.
Most of the time, this is really a newbie mistake, hence the fixit.
llvm-svn: 158230
The integral APSInt value is now stored in a decomposed form and the backing
store for large values is allocated via the ASTContext. This way its not
leaked as TemplateArguments are never destructed when they are allocated in
the ASTContext. Since the integral data is immutable it is now shared between
instances, making copying TemplateArguments a trivial operation.
Currently getting the integral data out of a TemplateArgument requires creating
a new APSInt object. This is cheap when the value is small but can be expensive
if it's not. If this turns out to be an issue a more efficient accessor could
be added.
llvm-svn: 158150
In addition, I've made the pointer and reference typedef 'void' rather than T*
just so they can't get misused. I would've omitted them entirely but
std::distance likes them to be there even if it doesn't use them.
This rolls back r155808 and r155869.
Review by Doug Gregor incorporating feedback from Chandler Carruth.
llvm-svn: 158104
temporary or an array subobject of a class temporary, and the resulting value
is used to initialize a pointer which outlives the temporary. Such a pointer
is always left dangling after the initialization completes and the array's
lifetime ends.
In order to detect this situation, this change also adds an
LValueClassification of LV_ArrayTemporary for temporaries of array type which
aren't subobjects of class temporaries. These occur in C++11 T{...} and GNU C++
(T){...} expressions, when T is an array type. Previously we treated the former
as a generic prvalue and the latter as a class temporary.
llvm-svn: 157955
Before:
test.cc:2:18: note: place parentheses around the == expression to silence this warning
if (0 == flags & 0xdd)
^
( )
Now:
test.cc:2:18: note: place parentheses around the == expression to silence this warning
if (0 == flags & 0xdd)
^
( )
llvm-svn: 157897
This comes up in the begin/end calls of a range-for (see the included test
case). Other suggestions are welcome, though this seems to do the trick without
regressing anything.
llvm-svn: 157553
lambda as referring to a local in an enclosing scope if we're in the
enclosing scope of the lambda (not it's function call operator). Also,
turn the test into an IR generation test, since that's where the
crashes occurred. Really fixes PR12746 / <rdar://problem/11465120>.
llvm-svn: 156926
This fixes the included test case & was reported by Nico Weber.
It's a little bit nasty using the difference in the conversion context, but
seems to me like a not unreasonable solution. I did have to fix up the
conversion context for conditional operators (it seems correct to me to include
the context for which we're actually doing the comparison - across all the
nested conditionals, rather than the innermost conditional which might not
actually have the problematic implicit conversion at all) and template default
arguments (this is a bit of a hack, since we don't have the source location of
the '=' anymore, so I just used the start of the parameter - open to
suggestions there)
llvm-svn: 156861
Sema::ConvertToIntegralOrEnumerationType() from PartialDiagnostics to
abstract "diagnoser" classes. Not much of a win here, but we're
-several PartialDiagnostics.
llvm-svn: 156217
Fariborz Jahanian