Commit Graph

13 Commits

Author SHA1 Message Date
Douglas Gregor 90a1a65194 Introduce a new expression type, UnresolvedDeclRefExpr, that describes
dependent qualified-ids such as

  Fibonacci<N - 1>::value

where N is a template parameter. These references are "unresolved"
because the name is dependent and, therefore, cannot be resolved to a
declaration node (as we would do for a DeclRefExpr or
QualifiedDeclRefExpr). UnresolvedDeclRefExprs instantiate to
DeclRefExprs, QualifiedDeclRefExprs, etc.

Also, be a bit more careful about keeping only a single set of
specializations for a class template, and instantiating from the
definition of that template rather than a previous declaration. In
general, we need a better solution for this for all TagDecls, because
it's too easy to accidentally look at a declaration that isn't the
definition.

We can now process a simple Fibonacci computation described as a
template metaprogram.

llvm-svn: 67308
2009-03-19 17:26:29 +00:00
Douglas Gregor c40290e452 Implement template instantiation for ClassTemplateSpecializationTypes,
such as replacing 'T' in vector<T>. There are a few aspects to this:

  - Extend TemplateArgument to allow arbitrary expressions (an
    Expr*), and switch ClassTemplateSpecializationType to store
    TemplateArguments rather than it's own type-or-expression
    representation.

  - ClassTemplateSpecializationType can now store dependent types. In
    that case, the canonical type is another
    ClassTemplateSpecializationType (with default template arguments
    expanded) rather than a declaration (we don't build Decls for
    dependent types).

  - Split ActOnClassTemplateId into ActOnClassTemplateId (called from
    the parser) and CheckClassTemplateId (called from
    ActOnClassTemplateId and InstantiateType). They're smart enough to
    handle dependent types, now.

llvm-svn: 66509
2009-03-09 23:48:35 +00:00
Douglas Gregor d56a91e8f6 Make the type associated with a ClassTemplateSpecializationDecl be a
nicely sugared type that shows how the user wrote the actual
specialization. This sugared type won't actually show up until we
start doing instantiations.

llvm-svn: 65577
2009-02-26 22:19:44 +00:00
Douglas Gregor 7f74112756 Implement parsing of nested-name-specifiers that involve template-ids, e.g.,
std::vector<int>::allocator_type

When we parse a template-id that names a type, it will become either a
template-id annotation (which is a parsed representation of a
template-id that has not yet been through semantic analysis) or a
typename annotation (where semantic analysis has resolved the
template-id to an actual type), depending on the context. We only
produce a type in contexts where we know that we only need type
information, e.g., in a type specifier. Otherwise, we create a
template-id annotation that can later be "upgraded" by transforming it
into a typename annotation when the parser needs a type. This occurs,
for example, when we've parsed "std::vector<int>" above and then see
the '::' after it. However, it means that when writing something like
this:

  template<> class Outer::Inner<int> { ... };

We have two tokens to represent Outer::Inner<int>: one token for the
nested name specifier Outer::, and one template-id annotation token
for Inner<int>, which will be passed to semantic analysis to define
the class template specialization.

Most of the churn in the template tests in this patch come from an
improvement in our error recovery from ill-formed template-ids.

llvm-svn: 65467
2009-02-25 19:37:18 +00:00
Douglas Gregor 67a6564091 Implement basic parsing and semantic analysis for explicit
specialization of class templates, e.g.,

  template<typename T> class X;

  template<> class X<int> { /* blah */ };

Each specialization is a different *Decl node (naturally), and can
have different members. We keep track of forward declarations and
definitions as for other class/struct/union types.

This is only the basic framework: we still have to deal with checking
the template headers properly, improving recovery when there are
failures, handling nested name specifiers, etc.

llvm-svn: 64848
2009-02-17 23:15:12 +00:00
Douglas Gregor 264ec4f237 Added ClassTemplateSpecializationDecl, which is a subclass of
CXXRecordDecl that is used to represent class template
specializations. These are canonical declarations that can refer to
either an actual class template specialization in the code, e.g.,

  template<> class vector<bool> { };

or to a template instantiation. However, neither of these features is
actually implemented yet, so really we're just using (and uniqing) the
declarations to make sure that, e.g., A<int> is a different type from
A<float>. Note that we carefully distinguish between what the user
wrote in the source code (e.g., "A<FLOAT>") and the semantic entity it
represents (e.g., "A<float, int>"); the former is in the sugared Type,
the latter is an actual Decl.

llvm-svn: 64716
2009-02-17 01:05:43 +00:00
Douglas Gregor f8f868336e Allow the use of default template arguments when forming a class
template specialization (e.g., std::vector<int> would now be
well-formed, since it relies on a default argument for the Allocator
template parameter). 

This is much less interesting than one might expect, since (1) we're
not actually using the default arguments for anything important, such
as naming an actual Decl, and (2) we'll often need to instantiate the
default arguments to check their well-formedness. The real fun will
come later.

llvm-svn: 64310
2009-02-11 18:16:40 +00:00
Douglas Gregor dba326363c Implement parsing, semantic analysis and ASTs for default template
arguments. This commit covers checking and merging default template
arguments from previous declarations, but it does not cover the actual
use of default template arguments when naming class template
specializations.

llvm-svn: 64229
2009-02-10 19:49:53 +00:00
Douglas Gregor 67b556a0da Eliminate TemplateArg so that we only have a single kind of
representation for template arguments. Also simplifies the interface
for ActOnClassTemplateSpecialization and eliminates some annoying
allocations of TemplateArgs.

My attempt at smart pointers for template arguments lists is
relatively lame. We can improve it once we're sure that we have the
right representation for template arguments.

llvm-svn: 64154
2009-02-09 19:34:22 +00:00
Douglas Gregor 8bf4205c70 Start processing template-ids as types when the template-name refers
to a class template. For example, the template-id 'vector<int>' now
has a nice, sugary type in the type system. What we can do now:

  - Parse template-ids like 'vector<int>' (where 'vector' names a
    class template) and form proper types for them in the type system.
  - Parse icky template-ids like 'A<5>' and 'A<(5 > 0)>' properly,
    using (sadly) a bool in the parser to tell it whether '>' should
    be treated as an operator or not.

This is a baby-step, with major problems and limitations:
  - There are currently two ways that we handle template arguments
  (whether they are types or expressions). These will be merged, and,
  most likely, TemplateArg will disappear.
  - We don't have any notion of the declaration of class template
  specializations or of template instantiations, so all template-ids
  are fancy names for 'int' :)

llvm-svn: 64153
2009-02-09 18:46:07 +00:00
Douglas Gregor cd72ba97e7 Semantic checking for class template declarations and
redeclarations. For example, checks that a class template
redeclaration has the same template parameters as previous
declarations.

Detangled class-template checking from ActOnTag, whose logic was
getting rather convoluted because it tried to handle C, C++, and C++
template semantics in one shot.

Made some inroads toward eliminating extraneous "declaration does not
declare anything" errors by adding an "error" type specifier.

llvm-svn: 63973
2009-02-06 22:42:48 +00:00
Douglas Gregor eff93e0401 Improve the representation of template type parameters. We now
canonicalize by template parameter depth, index, and name, and the
unnamed version of a template parameter serves as the canonical.

TemplateTypeParmDecl no longer needs to inherit from
TemplateParmPosition, since depth and index information is present
within the type.

llvm-svn: 63899
2009-02-05 23:33:38 +00:00
Douglas Gregor ded2d7b021 Basic representation of C++ class templates, from Andrew Sutton.
llvm-svn: 63750
2009-02-04 19:02:06 +00:00