The problem is as follows: C++11 has contexts which are not
potentially-evaluated, and yet in which we are required or encouraged to
perform constant evaluation. In such contexts, we are not permitted to
implicitly define special member functions for literal types, therefore
we cannot evalaute those constant expressions.
Punt on this in one more context for now by skipping checking constexpr
variable initializers if they occur in dependent contexts.
llvm-svn: 166956
whether the initializer is value-dependent rather than whether we are in a
dependent context. This allows us to detect some errors sooner, and fixes a
crash-on-invalid if a dependent type leaks out to a non-dependent context in
error recovery.
llvm-svn: 166898
might have been used in constant expressions, rather than suppressing it for
variables which are const. The important thing here is that such variables
can have their values used without actually being marked as 'used'.
llvm-svn: 166896
libraries have an incorrect definition of std::common_type (inherited from a
bug in the standard -- see LWG issue 2141), whereby they produce reference
types when they should not.
If we instantiate a typedef named std::common_type<...>::type, which is defined
in a system header as decltype(... ? ... : ...), and the decltype produces a
reference type, convert it to the non-reference type. (This doesn't affect any
LWG2141-conforming implementation of common_type, such as libc++'s, because the
default implementation of common_type<...>::type isn't supposed to produce a
reference type.)
This is horrible. I'm really sorry. :( Better ideas appreciated!
llvm-svn: 166455
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
GCC and Clang both do not warn on:
struct a { virtual void func(); };
struct b: a { virtual void func(); void func(int); };
struct c: b { void func(int); using b::func; };
but if the "using" was using a::func GCC would still remain silent where Clang
would warn. This change makes Clang consistent with GCC's existing behavior.
llvm-svn: 166154
This implementation doesn't warn on anything that GCC doesn't warn on with the
exception of templates specializations (GCC doesn't warn, Clang does). The
specific skipped cases (boolean, constant expressions, enums) are open for
debate/adjustment if anyone wants to demonstrate that GCC is being overly
conservative here. The only really obvious false positive I found was in the
Clang regression suite's MPI test - apparently MPI uses specific flag values in
pointer constants. (eg: #define FOO (void*)~0)
llvm-svn: 166039
a non-inline namespace, then reopens it as inline to try to add its symbols to
the surrounding namespace. In this one special case, permit the namespace to be
reopened as inline, and patch up the name lookup tables to match.
llvm-svn: 165263
- General C++11 attributes were previously parsed and ignored. Now they are parsed and stored in AST.
- Add support to parse arguments of attributes that in 'gnu' namespace.
- Differentiate unknown attributes and known attributes that can't be applied to statements when emitting diagnostic.
llvm-svn: 165082
Also applies to -Wnonnull, -Wtype-safety, and -Wnon-pod-varargs.
All of these can be better checked at instantiation time.
This change does not actually affect regular CallExpr function calls,
since the checks there only happen after overload resolution.
However, it will affect Objective-C method calls.
<rdar://problem/12373934>
llvm-svn: 164984
-Allow Sema to do more processing on the initial Expr before checking it.
-Remove the special conditions in HandleExpr()
-Move the code so that only one call site is needed.
-Removed the function from Sema and only call it locally.
-Warn on potentially evaluated reference variables, not just casts to r-values.
-Update tests.
llvm-svn: 164951
Summary:
When issuing a diagnostic message for the -Wimplicit-fallthrough diagnostics, always try to find the latest macro, defined at the point of fallthrough, which is immediately expanded to "[[clang::fallthrough]]", and use it's name instead of the actual sequence.
Known issues:
* uses PP.getSpelling() to compare macro definition with a string (anyone can suggest a convenient way to fill a token array, or maybe lex it in runtime?);
* this can be generalized and used in other similar cases, any ideas where it should reside then?
Reviewers: doug.gregor, rsmith
Reviewed By: rsmith
CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D50
llvm-svn: 164858
where an attribute is attached to a forward declaration of a template function,
and refers to parameters of that declaration, but is then inherited by the
definition of that function. When the definition is instantiated, the
parameter references need to be remapped.
llvm-svn: 164710
function being instantiated. An error recovery codepath was recursively
performing name lookup (and triggering an unbounded stack of template
instantiations which blew out the stack before hitting the depth limit).
Patch by Wei Pan!
llvm-svn: 164586
This makes the wording more informative, and consistent with the other
warnings about uninitialized variables.
Also, me and David who reviewed this couldn't figure out why we would
need to do a lookup to get the name of the variable; so just print the
name directly.
llvm-svn: 164366
but can be dereferenced to form an expression which does have viable begin/end
functions, then typo-correct the range, even if something else goes wrong with
the statement (such as inaccessible begin/end or the wrong type of loop
variable).
In order to ensure we recover correctly and produce any followup diagnostics in
this case, redo semantic analysis on the for-range statement outside of the
diagnostic trap, after issuing the typo-correction.
llvm-svn: 164323
This makes Clang warn about self references in in-class initializers,
for example:
struct S {
int a = a + 42;
};
This basically just moves UninitializedFieldVisitor up a bit in
SemaDeclCXX.cpp, and adds a call to it from ActOnCXXInClassMemberInitializer.
llvm-svn: 164131
is no compelling argument that this is a generally useful warning,
and imposes a strong stylistic argument on code beyond what it was
intended to find warnings in.
llvm-svn: 164083
type checking for non-static data member initializers in a dependent
class, because our ASTs lose too much information to when
type-checking an initializer. Fixes <rdar://problem/11974632>,
although the result is still rather unsatisfactory.
llvm-svn: 163871
TypeSourceInfo, we may have lost some adjustments made to the type of
that function due to declaration merging. Adjust the resulting type
correspondingly. Fixes PR12948 / <rdar://problem/11552434>.
llvm-svn: 163845
warning to an error. C++ bans it, and both GCC and EDG diagnose it as
an error. Microsoft allows it, so we still warn in Microsoft
mode. Fixes <rdar://problem/11135644>.
llvm-svn: 163831
A couple of missing "RequireNonAbstractType" calls in conditional operator
handling. I looked for opportunities to tie this check in to all relevant
callers of PerformCopyInitialization (couldn't be all callers since this is
called for base subobject copying too, where it's acceptable to copy abstract
types) but the callers varied too much & in many cases had substantial code
or conditionals on the RequireNonAbstractType call, the
PerformCopyInitialization call, or the code between the two calls.
llvm-svn: 163555
analysis that may give false positives because it is confused by aliasing, and
a less precise analysis that has fewer false positives, but may have false
negatives. The more precise warnings are enabled by -Wthread-safety-precise.
An additional note clarify the warnings in the precise case.
llvm-svn: 163537
(__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
(__is_pod, __is_signed, etc.) to normal identifiers if they are
encountered in certain places in the grammar where we know that prior
versions of libstdc++ or libc++ use them, to still allow the use of
these keywords as type traits. Fixes <rdar://problem/9836262> and PR10184.
llvm-svn: 162937
CheckLValueConstantExpression.
Richard pointed out that using the address of a TLS variable is ok in a
core C++11 constant expression, as long as it isn't part of the eventual
result of constant expression evaluation. Having the check in
CheckLValueConstantExpression accomplishes this.
llvm-svn: 162850
This warns in two specific situations:
1) For potentially swapped function arguments, e.g.
void foo(bool, float);
foo(1.7, false);
2) Misplaced brackets around function call arguments, e.g.
bool InRange = fabs(a - b < delta);
Where the last argument in a function call is implicitly converted
from bool to float, and the function returns a float which gets
implicitly converted to bool.
Patch by Andreas Eckleder!
llvm-svn: 162763
The old error message stating that 'begin' was an undeclared identifier
is replaced with a new message explaining that the error is in the range
expression, along with which of the begin() and end() functions was
problematic if relevant.
Additionally, if the range was a pointer type or defines operator*,
attempt to dereference the range, and offer a FixIt if the modified range
works.
llvm-svn: 162248
nested names as id-expressions, using the annot_primary_expr annotation, where
possible. This removes some redundant lookups, and also allows us to
typo-correct within tentative parsing, and to carry on disambiguating past an
identifier which we can determine will fail lookup as both a type and as a
non-type, allowing us to disambiguate more declarations (and thus offer
improved error recovery for such cases).
This also introduces to the parser the notion of a tentatively-declared name,
which is an identifier which we *might* have seen a declaration for in a
tentative parse (but only if we end up disambiguating the tokens as a
declaration). This is necessary to correctly disambiguate cases where a
variable is used within its own initializer.
llvm-svn: 162159
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
A conditional operator between glvalues of types cv1 T and cv2 T produces a
glvalue if the expressions are of the same value kind and one of cv1 and cv2
is a subset of the other.
A conditional operator between two null pointer constants is permitted if one
of them is of type std::nullptr_t.
llvm-svn: 161476
and the other is a glvalue of class type, don't forget to copy-initialize a
temporary when performing the lvalue-to-rvalue conversion on the glvalue.
Strangely, DefaultLvalueConversions misses this part of the lvalue-to-rvalue
conversions.
llvm-svn: 161450
for side-effects. Instead, check for side-effects after performing
initialization. Doing so also removes some strange corner cases and differences
between in-class initialization and constructor initialization.
llvm-svn: 161449
in duplicate -Wuninitialized warnings. Change so that only the check in
TryConstructorInitialization() will be used and a single warning be emitted.
llvm-svn: 161345
accurate by asking the parser whether there was an ambiguity rather than trying
to reverse-engineer it from the DeclSpec. Make the with-parameters case have
better diagnostics by using semantic information to drive the warning,
improving the diagnostics and adding a fixit.
Patch by Nikola Smiljanic. Some minor changes by me to suppress diagnostics for
declarations of the form 'T (*x)(...)', which seem to have a very high false
positive rate, and to reduce indentation in 'warnAboutAmbiguousFunction'.
llvm-svn: 160998
When performing the simplistic overload resolution for single-argument methods,
don't check the best overload for ambiguity with itself when the best overload
doesn't happen to be the first one.
Fixes PR13480.
llvm-svn: 160961
expressions to have complete return types (or accessible destructors). If the
return type is required to be complete for some other reason (for instance, if
it is needed by overload resolution), then it will still be required to be
complete. This is apparently required in order to parse a MSVC11 header.
llvm-svn: 160924
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
Rather than adding a ContainsUnexpandedParameterPack bit to essentially every
AST node, we tunnel the bit directly up to the surrounding lambda expression
when we reach a context where an unexpanded pack can not normally appear.
Thus any statement or declaration within a lambda can now potentially contain
an unexpanded parameter pack.
llvm-svn: 160705
A warning was added in r150128 for returning non-C compatible
user-defined types from functions with C linkage.
This makes the text more clear for the case when the type isn't
decidedly non-C compatible, but incomplete.
llvm-svn: 160681
In Microsoft mode, we emit a warning instead of an error.
This fixes a couple of errors when parsing the MSVC 11 RC headers with clang.
llvm-svn: 160613
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
use out of TransferFunctions, and compute it in advance rather than on-the-fly.
This allows us to handle compound assignments with DeclRefExprs on the RHS
correctly, and also makes it trivial to treat const& function parameters as not
initializing the argument. The patch also makes both of those changes.
llvm-svn: 160330
instead push the terminator for the branch down into the basic blocks of the subexpressions of '&&' and '||'
respectively. This eliminates some artifical control-flow from the CFG and results in a more
compact CFG.
Note that this patch only alters the branches 'while', 'if' and 'for'. This was complex enough for
one patch. The remaining branches (e.g., do...while) can be handled in a separate patch, but they
weren't immediately tackled because they were less important.
It is possible that this patch introduces some subtle bugs, particularly w.r.t. to destructor placement.
I've tried to audit these changes, but it is also known that the destructor logic needs some refinement
in the area of '||' and '&&' regardless (i.e., their are known bugs).
llvm-svn: 160218
This is accomplished by making VerifyDiagnosticsConsumer a CommentHandler,
which then only reads the -verify directives that are actually in live
blocks of code. It also makes it simpler to handle -verify directives that
appear in header files, though we still have to manually reparse some files
depending on how they are generated.
This requires some test changes. In particular, all PCH tests now have their
-verify directives outside the "header" portion of the file, using the @line
syntax added in r159978. Other tests have been modified mostly to make it
clear what is being tested, and to prevent polluting the expected output with
the directives themselves.
Patch by Andy Gibbs! (with slight modifications)
The new Frontend/verify-* tests exercise the functionality of this commit,
as well as r159978, r159979, and r160053 (Andy's other -verify enhancements).
llvm-svn: 160068
multidimensional array of class type. Also, preserve zero-initialization when
evaluating an initializer list for an array, in case the initializers refer to
later elements (which have preceding zero-initialization).
llvm-svn: 159904
duplicates attributes on the declaration. Also eliminates a false negative in
ReleasableMutexLock. Fixing this bug required some refactoring.
llvm-svn: 159780
actually perform value initialization rather than trying to fake it with a call
to the default constructor. Fixes various bugs related to the previously-missing
zero-initialization in this case.
I've also moved this and the other list initialization 'special case' from
TryConstructorInitialization into TryListInitialization where they belong.
llvm-svn: 159733
template instantiation. I wasn't able to reproduce this down to
anything small enough to put in our test suite, but it's "obviously"
okay to set the invalid bit earlier and precludes a
known-broken-but-not-marked-broken class from being used elsewhere.
llvm-svn: 159584
constexpr function evaluation, and corresponding ASan / valgrind issue in
tests, by storing the corresponding value with the relevant stack frame. This
also prevents re-evaluation of the source of the underlying OpaqueValueExpr,
which makes a major performance difference for certain contrived code (see
testcase update).
llvm-svn: 159189
This works around a quirk in the way that explicit template specializations are
handled in Clang. We generate an implicit declaration from the original
template which the explicit specialization is considered to redeclare. This
trips up the explicit delete logic.
This change only works around that strange representation. At some point it'd
be nice to remove those extra declarations to make the AST more accurately
reflect the C++ semantics.
Review by Doug Gregor.
llvm-svn: 159167
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
properly if there is a join point in the control flow graph that involves
a trylock. Also changes the source locations of some warnings to be
more consistent.
llvm-svn: 159008
Revert "If an object (such as a std::string) with an appropriate c_str() member function"
This reverts commit 7d96f6106bfbd85b1af06f34fdbf2834aad0e47e.
llvm-svn: 158949
This now correctly covers, I believe, all the pointer types:
* 'any' pointers (both function and data normal pointers and ObjC object pointers)
* member pointers (both function and data)
* block pointers
llvm-svn: 158931
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
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
because it expects a reference and receives a non-l-value.
For example, given:
int foo(int &);
template<int x> void b() { foo(x); }
clang will now print "expects an l-value for 1st argument" instead of
"no known conversion from 'int' to 'int &' for 1st argument". The change
in wording (and associated code to detect the case) was prompted by
comment #5 in PR3104, and should be the last bit of work needed for the
bug.
llvm-svn: 158691
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
Now, as long as the 'Namespaces' variable is correct inside Attr.td, the
generated code will correctly admit a C++11 attribute only when it has the
appropriate namespace(s).
llvm-svn: 158661
Eli Friedman