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
Douglas Gregor