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
the "" and the suffix; that breaks names such as 'operator""if'. For symmetry,
also remove the space between the 'operator' and the '""'.
llvm-svn: 249641
Unqualified templated constructors cannot be friended and our lack of a
diagnostic led to violated invariants. Instead, raise a diagnostic when
processing the friend declaration.
This fixes PR20251.
llvm-svn: 248953
specification) to an error. No compiler other than Clang seems to allow this,
and it doesn't seem like a useful thing to accept as an extension in general.
The current behavior was added for PR5957, where the problem was specifically
related to mismatches of the exception specification on the implicitly-declared
global operator new and delete. To retain that workaround, we downgrade the
error to an ExtWarn when the declaration is of a replaceable global allocation
function.
Now that this is an error, stop trying (and failing) to recover from a missing
computed noexcept specification. That recovery didn't work, and led to crashes
in code like the added testcase.
llvm-svn: 248867
Our string literal parser copied any source-file new-line characters
into the execution string-literal. This is incorrect if the source-file
new-line character was a \r\n sequence because new-line characters are
merely \n.
llvm-svn: 248392
If a function declaration is found inside a template function as in:
template<class T> void f() {
void g(int x = T::v) except(T::w);
}
it must be instantiated along with the enclosing template function,
including default arguments and exception specification.
Together with the patch committed in r240974 this implements DR1484.
Differential Revision: http://reviews.llvm.org/D11194
llvm-svn: 245810
So, we now reject that. We also warn for any external-linkage global
variable named main in C, because it results in undefined behavior.
PR: 24309
Differential Revision: http://reviews.llvm.org/D11658
Reviewed by: rsmith
llvm-svn: 245051
the identifier table. This is redundant, since the TU-scope lookups are also
serialized as part of the TU DeclContext, and wasteful in a number of ways. We
still emit the decls for PCH / preamble builds, since for those we want
identical results, not merely semantically equivalent ones.
llvm-svn: 242855
We referred to all declaration in definitions in our diagnostic messages
which is can be inaccurate. Instead, classify the declaration and emit
an appropriate diagnostic for the new declaration and an appropriate
note pointing to the old one.
This fixes PR24116.
llvm-svn: 242190
This patch adds ObjectFilePCHContainerOperations uses the LLVM backend
to put the contents of a PCH into a __clangast section inside a COFF, ELF,
or Mach-O object file container.
This is done to facilitate module debugging by makeing it possible to
store the debug info for the types defined by a module alongside the AST.
rdar://problem/20091852
llvm-svn: 241620
We didn't check the return result of BuildDecltypeType, resulting in us
crashing when we tried to grab the canonical version of the type.
This fixes PR23995.
llvm-svn: 241131
This patch implements the functionality specified by DR948.
The changes are two fold. First, the parser was modified
to allow 'constexpr's to appear in condition declarations
(which was a hard error before). Second, Sema was modified
to cleanup maybe odr-used declarations by way of a call to
'ActOnFinishFullExpr'. As 'constexpr's were not allowed in
condition declarations before the cleanup wasn't necessary
(such declarations were always odr-used).
This fixes PR22491.
Differential Revision: http://reviews.llvm.org/D8978
llvm-svn: 240707
The method wasn't an overrider but didn't have 'virtual' textually
written because our CXXMethodDecl was an out-of-line definition. Make
sure we use the canonical decl instead.
This fixes PR23629.
llvm-svn: 237999
The error has the form ... 'int' ... 'const int' ... dropped qualifiers. At
first glance, it appears that the const qualifier is added. Reverse the types
so that the second type is less qualified than the first.
llvm-svn: 237482
Previously we'd try to perform checks on the captures from the middle of
parsing the lambda's body, at the point where we detected that a variable
needed to be captured. This was wrong in a number of subtle ways. In
PR23334, we couldn't correctly handle the list of potential odr-uses
resulting from the capture, and our attempt to recover from that resulted
in a use-after-free.
We now defer building the initialization expression until we leave the lambda
body and return to the enclosing context, where the initialization does the
right thing. This patch only covers lambda-expressions, but we should apply
the same change to blocks and captured statements too.
llvm-svn: 235921
We didn't correctly expect a QualifiedTypeLoc when faced with fixing a
variable array type into a constant array type.
Differential Revision: http://reviews.llvm.org/D8958
llvm-svn: 235251
r235046 turned "extern __declspec(selectany) int a;" from a declaration into
a definition to fix PR23242 (required for compatibility with mc.exe output).
However, this broke parsing Windows headers: A d3d11 headers contain something
like
struct SomeStruct {};
extern const __declspec(selectany) SomeStruct some_struct;
This is now a definition, and const objects either need an explicit default
ctor or an initializer so this errors out with
d3d11.h(1065,48) :
error: default initialization of an object of const type
'const CD3D11_DEFAULT' without a user-provided default constructor
(cl.exe just doesn't implement this rule, independent of selectany.)
To work around this, weaken this error into a warning for selectany decls
in microsoft mode, and recover with zero-initialization.
Doing this is a bit hairy since it adds a fixit on an error emitted
by InitializationSequence – this means it needs to build a correct AST, which
in turn means InitializationSequence::Failed() cannot return true when this
fixit is applied. As a workaround, the patch adds a fixit member to
InitializationSequence, and InitializationSequence::Perform() prints the
diagnostic if the fixit member is set right after its call to Diagnose.
That function is usually called when InitializationSequences are used –
InitListChecker::PerformEmptyInit() doesn't call it, but the InitListChecker
case never performs default-initialization, so this is technically OK.
This is the alternative, original fix for PR20208 that got reviewed in the
thread "[patch] Improve diagnostic on default-initializing const variables
(PR20208)". This change basically reverts r213725, adds the original fix for
PR20208, and makes the error a warning in Microsoft mode.
llvm-svn: 235166
Previously, many error messages would simply be "read-only variable is not
assignable" This change provides more information about why the variable is
not assignable, as well as note to where the const is located.
Differential Revision: http://reviews.llvm.org/D4479
llvm-svn: 234677
Faisal Vali