With this patch compiler emits warning if it tries to make implicit instantiation
of a template but cannot find the template definition. The warning can be suppressed
by explicit instantiation declaration or by command line options
-Wundefined-var-template and -Wundefined-func-template. The implementation follows
the discussion of http://reviews.llvm.org/D12326.
Differential Revision: http://reviews.llvm.org/D16396
llvm-svn: 266719
Summary: A program shall not declare an explicit instantiation (14.8.2), an explicit specialization (14.8.3), or a partial specialization of a concept definition.
Reviewers: rsmith, hubert.reinterpretcast, faisalv, aaron.ballman
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D18221
llvm-svn: 265868
Implement lambda capture of *this by copy.
For e.g.:
struct A {
int d = 10;
auto foo() { return [*this] (auto a) mutable { d+=a; return d; }; }
};
auto L = A{}.foo(); // A{}'s lifetime is gone.
// Below is still ok, because *this was captured by value.
assert(L(10) == 20);
assert(L(100) == 120);
If the capture was implicit, or [this] (i.e. *this was captured by reference), this code would be otherwise undefined.
Implementation Strategy:
- amend the parser to accept *this in the lambda introducer
- add a new king of capture LCK_StarThis
- teach Sema::CheckCXXThisCapture to handle by copy captures of the
enclosing object (i.e. *this)
- when CheckCXXThisCapture does capture by copy, the corresponding
initializer expression for the closure's data member
direct-initializes it thus making a copy of '*this'.
- in codegen, when assigning to CXXThisValue, if *this was captured by
copy, make sure it points to the corresponding field member, and
not, unlike when captured by reference, what the field member points
to.
- mark feature as implemented in svn
Much gratitude to Richard Smith for his carefully illuminating reviews!
llvm-svn: 263921
If we import a module that has a complete array type and one that has an
incomplete array type, the declaration found by name lookup might be the one with
the incomplete type, possibly resulting in rejects-valid.
Now, the name lookup prefers decls with a complete array types. Also,
diagnose cases when the redecl chain has array bound, different from the merge
candidate.
Reviewed by Richard Smith.
llvm-svn: 262189
C++11 requires const objects to have a user-provided constructor, even for
classes without any fields. DR 253 relaxes this to say "If the implicit default
constructor initializes all subobjects, no initializer should be required."
clang is currently the only compiler that implements this C++11 rule, and e.g.
libstdc++ relies on something like DR 253 to compile in newer versions. This
change makes it possible to build code that says `const vector<int> v;' again
when using libstdc++5.2 and _GLIBCXX_DEBUG
(https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60284).
Fixes PR23381.
http://reviews.llvm.org/D16552
llvm-svn: 261297
diagnosing when 'concept' is specified on a function or template
specialization.
Since a concept can only be applied to a function or variable template,
the concept bit is stored in TemplateDecl as a PointerIntPair.
Reviewers: rsmith, faisalv, aaron.ballman, hubert.reinterpretcast
Differential Revision: http://reviews.llvm.org/D13357
llvm-svn: 260074
Fix the issue discovered by fuzzing (PR23057, comment 18) by handling nullptr in Sema::ActOnCXXForRangeDecl
and correct delayed typos in for-range expression before calling Sema::ActOnCXXForRangeStmt. Also fixes PR26288.
Differential Revision: http://reviews.llvm.org/D16630
llvm-svn: 259532
Switch the evaluation from isIntegerConstantExpr to EvaluateAsInt.
EvaluateAsInt will evaluate more types of expressions than
isIntegerConstantExpr.
Move one case from -Wsign-conversion to -Wconstant-conversion. The case is:
1) Source and target types are signed
2) Source type is wider than the target type
3) The source constant value is positive
4) The conversion will store the value as negative in the target.
llvm-svn: 259271
Diagnose if the return type of a function concept or declaration type of a
variable concept is not bool.
Reviewers: hubert.reinterpretcast
Differential Revision: http://reviews.llvm.org/D16163
llvm-svn: 259159
into IDNS_Tag in C++, because they conflict with redeclarations of tags. (This
doesn't affect elaborated-type-specifier lookup, which looks for IDNS_Type in
C++).
llvm-svn: 256985
endings, since the file is supposed to have them, according to its
comments. Also set its svn:eol-style property. Noticed by Nico Weber.
llvm-svn: 256742
Summary:
There are a number of files in the tree which have been accidentally checked in with DOS line endings. Convert these to native line endings.
There are also a few files which have DOS line endings on purpose, and I have set the svn:eol-style property to 'CRLF' on those.
Reviewers: joerg, aaron.ballman
Subscribers: aaron.ballman, cfe-commits
Differential Revision: http://reviews.llvm.org/D15849
llvm-svn: 256704
by overload resolution because deduction succeeds, but the substituted
parameter type for some parameter (with deduced type) doesn't exactly match the
corresponding adjusted argument type.
llvm-svn: 256657
It resolves clang selfhosting with std::once() for Cygwin.
FIXME: It may be EmulatedTLS-generic also for X86-Android.
FIXME: Pass EmulatedTLS to LLVM CodeGen from Clang with -femulated-tls.
llvm-svn: 256134
have a nested name specifier. Strictly speaking, forward declarations of class
template partial specializations are not permitted at all, but that seems like
an obvious wording defect, and if we allow them without a nested name specifier
we should also allow them with a nested name specifier.
llvm-svn: 255383
https://llvm.org/bugs/show_bug.cgi?id=24694http://wg21.link/cwg1591
Teach DeduceFromInitializerList in SemaTemplateDeduction.cpp to deduce against array (constant and dependent sized) parameters (really, reference to arrays since they don't decay to pointers), by checking if the template parameter is either one of those kinds of arrays, and if so, deducing each initializer list element against the element type, and then deducing the array bound if needed.
In brief, this patch enables the following code:
template<class T, int N> int *f(T (&&)[N]);
int *ip = f({1, 2, 3});
llvm-svn: 255221
This is the 5th Lit test patch.
Expanded expected diagnostics to vary by C++ dialect.
Expanded RUN line to: default, C++98/03 and C++11.
llvm-svn: 255196
do scope-based lookup when looking for redeclarations of them. Add some related
missing checks for the scope-based redeclaration lookup: properly filter the
list of found declarations to match the scope, and diagnose shadowing of a
template parameter name.
llvm-svn: 254663
side-effect, so that we don't allow speculative evaluation of such expressions
during code generation.
This caused a diagnostic quality regression, so fix constant expression
diagnostics to prefer either the first "can't be constant folded" diagnostic or
the first "not a constant expression" diagnostic depending on the kind of
evaluation we're doing. This was always the intent, but didn't quite work
correctly before.
This results in certain initializers that used to be constant initializers to
no longer be; in particular, things like:
float f = 1e100;
are no longer accepted in C. This seems appropriate, as such constructs would
lead to code being executed if sanitizers are enabled.
llvm-svn: 254574
This patch emits a more appropriate (but still noisy) diagnostic stream when a lambda-expression is encountered within a non-type default argument.
For e.g. template<int N = ([] { return 5; }())> int f();
As opposed to complaining that a lambda expression is not allowed in an unevaluated operand, the patch complains about the lambda being forbidden in a constant expression context (which will be allowed in C++17 now that they have been accepted by EWG, unless of course CWG or national bodies (that have so far shown no signs of concern) rise in protest)
As I start submitting patches for constexpr lambdas (http://wg21.link/P0170R0) under C++1z (OK'd by Richard Smith at Kona), this will be one less change to make.
Thanks!
llvm-svn: 253431
DR407, the C++ standard doesn't really say how this should work. Here's what we
do (which is consistent with DR407 as far as I can tell):
* When performing name lookup for an elaborated-type-specifier, a tag
declaration hides a typedef declaration that names the same type.
* When performing any other kind of lookup, a typedef declaration hides
a tag declaration that names the same type.
In any other case where lookup finds both a typedef and a tag (that is, when
they name different types), the lookup will be ambiguous. If lookup finds a
tag and a typedef that name the same type, and finds anything else, the lookup
will always be ambiguous (even if the other entity would hide the tag, it does
not also hide the typedef).
llvm-svn: 252959
https://gcc.gnu.org/onlinedocs/gcc/Typeof.html
Differences from the GCC extension:
* __auto_type is also permitted in C++ (but only in places where
it could appear in C), allowing its use in headers that might
be shared across C and C++, or used from C++98
* __auto_type can be combined with a declarator, as with C++ auto
(for instance, "__auto_type *p")
* multiple variables can be declared in a single __auto_type
declaration, with the C++ semantics (the deduced type must be
the same in each case)
This patch also adds a missing restriction on applying typeof to
a bit-field, which GCC has historically rejected in C (due to
lack of clarity as to whether the operand should be promoted).
The same restriction also applies to __auto_type in C (in both
GCC and Clang).
This also fixes PR25449.
Patch by Nicholas Allegra!
llvm-svn: 252690
std::initializer_list<T> type. Instead, the list must contain a single element
and the type is deduced from that.
In Clang 3.7, we warned by default on all the cases that would change meaning
due to this change. In Clang 3.8, we will support only the new rules -- per
the request in N3922, this change is applied as a Defect Report against earlier
versions of the C++ standard.
This change is not entirely trivial, because for lambda init-captures we
previously did not track the difference between direct-list-initialization and
copy-list-initialization. The difference was not previously observable, because
the two forms of initialization always did the same thing (the elements of the
initializer list were always copy-initialized regardless of the initialization
style used for the init-capture).
llvm-svn: 252688
Summary: Diagnose when the 'concept' specifier is used on a typedef or function parameter.
Reviewers: rsmith, hubert.reinterpretcast, aaron.ballman, faisalv
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D14316
llvm-svn: 252061
These test updates almost exclusively around the change in behavior
around enum: enums without a definition are considered incomplete except
when targeting MSVC ABIs. Since these tests are interested in the
'incomplete-enum' behavior, restrict them to %itanium_abi_triple.
llvm-svn: 249660
Serge Pavlov