by distinguishing between substitution that occurs for template
argument deduction vs. explicitly-specifiad template arguments. This
is used both to improve diagnostics and to make sure we only provide
SFINAE in those cases where SFINAE should apply.
In addition, deal with the sticky issue where SFINAE only considers
substitution of template arguments into the *type* of a function
template; we need to issue hard errors beyond this point, as
test/SemaTemplate/operator-template.cpp illustrates.
llvm-svn: 74651
Remove ASTContext parameter from DeclContext's methods. This change cascaded down to other Decl's methods and changes to call sites started "escalating".
Timings using pre-tokenized "cocoa.h" showed only a ~1% increase in time run between and after this commit.
llvm-svn: 74506
of template instantiation, we were dropping cv-qualifiers on the
instantiated type in a few places. This change reshuffles the
type-instantiation code a little bit so that there's a single place
where we add qualifiers to the instantiated type, so that we won't end
up with this same bug in the future.
llvm-svn: 74331
For a FunctionDecl that has been instantiated due to template argument
deduction, we now store the primary template from which it was
instantiated and the deduced template arguments. From this
information, we can instantiate the body of the function template.
llvm-svn: 74232
compilation, and (hopefully) introduce RAII objects for changing the
"potentially evaluated" state at all of the necessary places within
Sema and Parser. Other changes:
- Set the unevaluated/potentially-evaluated context appropriately
during template instantiation.
- We now recognize three different states while parsing or
instantiating expressions: unevaluated, potentially evaluated, and
potentially potentially evaluated (for C++'s typeid).
- When we're in a potentially potentially-evaluated context, queue
up MarkDeclarationReferenced calls in a stack. For C++ typeid
expressions that are potentially evaluated, we will play back
these MarkDeclarationReferenced calls when we exit the
corresponding potentially potentially-evaluated context.
- Non-type template arguments are now parsed as constant
expressions, so they are not potentially-evaluated.
llvm-svn: 73899
Add a type (ObjCObjectPointerType) and remove a type (ObjCQualifiedIdType).
This large/tedious patch is just a first step. Next step is to remove ObjCQualifiedInterfaceType. After that, I will remove the magic TypedefType for 'id' (installed by Sema). This work will enable various simplifications throughout clang (when dealing with ObjC types).
No functionality change.
llvm-svn: 73649
Implement support for C++ Substitution Failure Is Not An Error
(SFINAE), which says that errors that occur during template argument
deduction do *not* produce diagnostics and do not necessarily make a
program ill-formed. Instead, template argument deduction silently
fails. This is currently implemented for template argument deduction
during matching of class template partial specializations, although
the mechanism will also apply to template argument deduction for
function templates. The scheme is simple:
- If we are in a template argument deduction context, any diagnostic
that is considered a SFINAE error (or warning) will be
suppressed. The error will be propagated up the call stack via the
normal means.
- By default, all warnings and errors are SFINAE errors. Add the
NoSFINAE class to a diagnostic in the .td file to make it a hard
error (e.g., for access-control violations).
Note that, to make this fully work, every place in Sema that emits an
error *and then immediately recovers* will need to check
Sema::isSFINAEContext() to determine whether it must immediately
return an error rather than recovering.
llvm-svn: 73332
I'm not completely sure this is the right way to fix this issue, but it seems
reasonable, and it's consistent with the non-template code for this
construct.
llvm-svn: 73285
argument deduction failed. For example, given
template<typename T> struct is_same<T, T> { ... };
template argument deduction will fail for is_same<int, float>, and now
reports enough information
Right now, we don't do anything with this extra information, but it
can be used for informative diagnostics that say, e.g., "template
argument deduction failed because T was deduced to 'int' in one
context and 'float' in another".
llvm-svn: 73237
partial specialization, substitute those template arguments back into
the template arguments of the class template partial specialization to
see if the results still match the original template arguments.
This code is more general than it needs to be, since we don't yet
diagnose C++ [temp.class.spec]p9. However, it's likely to be needed
for function templates.
llvm-svn: 73196
- Once we have deduced template arguments for a class template partial
specialization, we use exactly those template arguments for instantiating
the definition of the class template partial specialization.
- Added template argument deduction for non-type template parameters.
- Added template argument deduction for dependently-sized array types.
With these changes, we can now implement, e.g., the remove_reference
type trait. Also, Daniel's Ackermann template metaprogram now compiles
properly.
llvm-svn: 72909
deductions of the same template parameter are equivalent. This allows
us to implement the is_same type trait (!).
Also, move template argument deduction into its own file and update a
few build systems with this change (grrrr).
llvm-svn: 72819
we have the basics of declaring and storing class template partial
specializations, matching class template partial specializations at
instantiation time via (limited) template argument deduction, and
using the class template partial specialization's pattern for
instantiation.
This patch is enough to make a simple is_pointer type trait work, but
not much else.
llvm-svn: 72662
printing logic to help customize the output. For now, we use this
rather than a special flag to suppress the "struct" when printing
"struct X" and to print the Boolean type as "bool" in C++ but "_Bool"
in C.
llvm-svn: 72590
declaration references. The key realization is that dependent Decls,
which actually require instantiation, can only refer to the current
instantiation or members thereof. And, since the current context
during instantiation contains all of those members of the current
instantiation, we can simply find the real instantiate that matches up
with the "current instantiation" template.
llvm-svn: 72486
instantiation of a declaration from the template version (or version
that lives in a template) and a given set of template arguments. This
needs much, much more testing, but it suffices for simple examples
like
typedef T* iterator;
iterator begin();
llvm-svn: 72461
template, introduce that member function into the template
instantiation stack. Also, add diagnostics showing the member function
within the instantiation stack and clean up the qualified-name
printing so that we get something like:
note: in instantiation of member function 'Switch1<int, 2, 2>::f'
requested here
in the template instantiation backtrace.
llvm-svn: 72015
template<typename T>
struct X {
struct Inner;
};
template struct X<int>::Inner;
This change is larger than it looks because it also fixes some
a problem with nested-name-specifiers and tags. We weren't requiring
the DeclContext associated with the scope specifier of a tag to be
complete. Therefore, when looking for something like "struct
X<int>::Inner", we weren't instantiating X<int>.
This, naturally, uncovered a problem with member pointers, where we
were requiring the left-hand side of a member pointer access
expression (e.g., x->*) to be a complete type. However, this is wrong:
the semantics of this expression does not require a complete type (EDG
agrees).
Stuart vouched for me. Blame him.
llvm-svn: 71756
of class members (recursively). Only member classes are actually
instantiated; the instantiation logic for member functions and
variables are just stubs.
llvm-svn: 71713
templates. In particular:
- An explicit instantiation can follow an implicit instantiation (we
were improperly diagnosing this as an error, previously).
- In C++0x, an explicit instantiation that follows an explicit
specialization of the same template specialization is ignored. In
C++98, we just emit an extension warning.
- In C++0x, an explicit instantiation must be in a namespace
enclosing the original template. C++98 has no such requirement.
Also, fixed a longstanding FIXME regarding the integral type that is
used for the size of a constant array type when it is being instantiated.
llvm-svn: 71689
still aren't instantiating the definitions of class template members,
and core issues 275 and 259 will both affect the checking that we do
for explicit instantiations (but are not yet implemented).
llvm-svn: 71613
TemplateArgumentList. This avoids the need to pass around
pointer/length pairs of template arguments lists, and will eventually
make it easier to introduce member templates and variadic templates.
llvm-svn: 71517
Douglas Gregor