VLA restrictions so that one can use VLAs in templates (even
accidentally), but not as part of a non-type template parameter (which
would be very bad).
llvm-svn: 104471
in several important ways:
- VLAs of non-POD types are not permitted.
- VLAs cannot be used in conjunction with C++ templates.
These restrictions are intended to keep VLAs out of the parts of the
C++ type system where they cause the most trouble. Fixes PR5678 and
<rdar://problem/8013618>.
llvm-svn: 104443
the required "template" keyword, using the same heuristics we do for
dependent template names in member access expressions, e.g.,
test/SemaTemplate/dependent-template-recover.cpp:11:8: error: use 'template'
keyword to treat 'getAs' as a dependent template name
T::getAs<U>();
^
template
Fixes PR5404.
llvm-svn: 104409
that is missing the 'template' keyword, e.g.,
t->getAs<T>()
where getAs is a member of an unknown specialization. C++ requires
that we treat "getAs" as a value, but that would fail to parse since T
is the name of a type. We would then fail at the '>', since a type
cannot be followed by a '>'.
This is a very common error for C++ programmers to make, especially
since GCC occasionally allows it when it shouldn't (as does Visual
C++). So, when we are in this case, we use tentative parsing to see if
the tokens starting at "<" can only be parsed as a template argument
list. If so, we produce a diagnostic with a fix-it that states that
the 'template' keyword is needed:
test/SemaTemplate/dependent-template-recover.cpp:5:8: error: 'template' keyword
is required to treat 'getAs' as a dependent template name
t->getAs<T>();
^
template
This is just a start of this patch; I'd like to apply the same
approach to everywhere that a template-id with dependent template name
can be parsed.
llvm-svn: 104406
"used" (e.g., we will refer to the vtable in the generated code) and
when they are defined (i.e., because we've seen the key function
definition). Previously, we were effectively tracking "potential
definitions" rather than uses, so we were a bit too eager about emitting
vtables for classes without key functions.
The new scheme:
- For every use of a vtable, Sema calls MarkVTableUsed() to indicate
the use. For example, this occurs when calling a virtual member
function of the class, defining a constructor of that class type,
dynamic_cast'ing from that type to a derived class, casting
to/through a virtual base class, etc.
- For every definition of a vtable, Sema calls MarkVTableUsed() to
indicate the definition. This happens at the end of the translation
unit for classes whose key function has been defined (so we can
delay computation of the key function; see PR6564), and will also
occur with explicit template instantiation definitions.
- For every vtable defined/used, we mark all of the virtual member
functions of that vtable as defined/used, unless we know that the key
function is in another translation unit. This instantiates virtual
member functions when needed.
- At the end of the translation unit, Sema tells CodeGen (via the
ASTConsumer) which vtables must be defined (CodeGen will define
them) and which may be used (for which CodeGen will define the
vtables lazily).
From a language perspective, both the old and the new schemes are
permissible: we're allowed to instantiate virtual member functions
whenever we want per the standard. However, all other C++ compilers
were more lazy than we were, and our eagerness was both a performance
issue (we instantiated too much) and a portability problem (we broke
Boost test cases, which now pass).
Notes:
(1) There's a ton of churn in the tests, because the order in which
vtables get emitted to IR has changed. I've tried to isolate some of
the larger tests from these issues.
(2) Some diagnostics related to
implicitly-instantiated/implicitly-defined virtual member functions
have moved to the point of first use/definition. It's better this
way.
(3) I could use a review of the places where we MarkVTableUsed, to
see if I missed any place where the language effectively requires a
vtable.
Fixes PR7114 and PR6564.
llvm-svn: 103718
explicit instantiations of template. C++0x clarifies the intent
(they're ill-formed in some cases; see [temp.explicit] for
details). However, one could squint at the C++98/03 standard and
conclude they are permitted, so reduce the error to a warning
(controlled by -Wc++0x-compat) in C++98/03 mode.
llvm-svn: 103482
different tag kind ("struct" vs. "class") than the primary template,
which has an affect on access control.
Should fix the last remaining Boost.Accumulors failure.
llvm-svn: 103144
ParseOptionalCXXScopeSpecifier() only annotates the subset of
template-ids which are not subject to lexical ambiguity. Add support
for the more general case in ParseUnqualifiedId() to handle cases
such as A::template B().
Also improve some diagnostic locations.
Fixes PR7030, from Alp Toker!
llvm-svn: 103081
parameter with pointer-to-member type, we may have to perform a
qualification conversion, since the pointee type of the parameter
might be more qualified than the pointee type of the argument we form
from the declaration. Fixes PR6986.
llvm-svn: 102777
of the mapping from local declarations to their instantiated
counterparts during template instantiation. Previously, we tried to do
some unholy merging of local instantiation scopes that involved
storing a single hash table along with an "undo" list on the
side... which was ugly, and never handled function parameters
properly.
Now, we just keep separate hash tables for each local instantiation
scope, and "combining" two scopes means that we'll look in each of the
combined hash tables. The combined scope stack is rarely deep, and
this makes it easy to avoid the "undo" issues we were hitting. Also,
I've simplified the logic for function parameters: if we're declaring
a function and we need the function parameters to live longer, we just
push them back into the local instantiation scope where we need them.
Fixes PR6990.
llvm-svn: 102732
specializations, which keeps track of the order in which they were
originally declared. We use this number so that we can always walk the
list of partial specializations in a predictable order during matching
or template instantiation. This also fixes a failure in Boost.Proto,
where SourceManager::isBeforeInTranslationUnit was behaving
poorly in inconsistent ways.
llvm-svn: 102693
entering the current instantiation. Set up a little to preserve type location
information for typename types while we're in there.
Fixes a Boost failure.
llvm-svn: 102673
bindings when the template argument is still an expression; it happens
while checking the template arguments of a class template partial
specializations. Fixes PR6964.
llvm-svn: 102595
of a class template or class template partial specialization. That is to
say, in
template <class T> class A { ... };
or
template <class T> class B<const T*> { ... };
make 'A<T>' and 'B<const T*>' sugar for the corresponding InjectedClassNameType
when written inside the appropriate context. This allows us to track the
current instantiation appropriately even inside AST routines. It also allows
us to compute a DeclContext for a type much more efficiently, at some extra
cost every time we write a template specialization (which can be optimized,
but I've left it simple in this patch).
llvm-svn: 102407
when they are not complete (since we could not match them up to
anything) and ensuring that enum parsing can cope with dependent
elaborated-type-specifiers. Fixes PR6915 and PR6649.
llvm-svn: 102247
(e.g., no typename, enum, class, etc.), e.g., because the context is
one that is known to refer to a type. Patch from Enea Zaffanella!
llvm-svn: 102243
a qualified name. We weren't checking for an empty
nested-name-specifier when dealing with friend class templates
(although we were checking in the other places where we deal with this
paragraph). Fixes a Boost.Serialization showstopper.
llvm-svn: 101724
intended for redeclarations, fixing those that need it. Fixes PR6831.
This uncovered an issue where the C++ type-specifier-seq parsing logic
would try to perform name lookup on an identifier after it already had
a type-specifier, which could also lead to spurious ambiguity errors
(as in PR6831, but with a different test case).
llvm-svn: 101419
in case it ends up doing something that might trigger diagnostics
(template instantiation, ambiguity reporting, access
reporting). Noticed while working on PR6831.
llvm-svn: 101412
ResolveAddressOfOverloadedFunction when asked to complain. Previously,
we had some weird handshake where ResolveAddressOfOverloadedFunction
expected its caller to handle some of the diagnostics but not others,
and yet there was no way for the caller to know which case we were
in. Eliminate this madness, fixing <rdar://problem/7765884>.
llvm-svn: 101312
generally recover from typos in keywords (since we would effectively
have to mangle the token stream). However, there are still benefits to
typo-correcting with keywords:
- We don't make stupid suggestions when the user typed something
that is similar to a keyword.
- We can suggest the keyword in a diagnostic (did you mean
"static_cast"?), even if we can't recover and therefore don't have
a fix-it.
llvm-svn: 101274
name-lookup ambiguities when there are multiple base classes that are
all specializations of the same class template. This is part of a
general cleanup for ambiguities in template-name lookup. Fixes
PR6717.
llvm-svn: 101065
specializations when the explicit instantiation was... explicitly
written, i.e., not the product of an explicit instantiation of an
enclosing class. Fixes this spurious warning when Clang builds LLVM:
/Volumes/Data/dgregor/Projects/llvm/lib/CodeGen/MachineDominators.cpp:22:1:
warning: explicit instantiation of 'addRoot' that occurs after an
explicit specialization will be ignored (C++0x extension) [-pedantic]
llvm-svn: 100900
parameter, explicitly ask the user to give it arguments. We used to
complain that it wasn't a type and expect the user to figure it out.
llvm-svn: 100729
an object or function. Our previous checking was too lax, and ended up
allowing missing or extraneous address-of operators, among other
evils. The new checking provides better diagnostics and adheres more
closely to the standard.
Fixes PR6563 and PR6749.
llvm-svn: 100125
(such as "class T::foo") from an ElaboratedType of a TypenameType to a
DependentNameType, which more accurately models the underlying
concept.
Improve template instantiation for DependentNameType nodes that
represent nested-name-specifiers, by performing tag name lookup and
checking the resulting tag appropriately. Fixes PR5681.
There is still much testing and cleanup to do in this area.
llvm-svn: 100054
John McCall