174 Commits

Author SHA1 Message Date
Douglas Gregor
f30101186f Implement substitution of a function parameter pack for its set of
instantiated function parameters, enabling instantiation of arbitrary
pack expansions involving function parameter packs. At this point, we
can now correctly compile a simple, variadic print() example:

  #include <iostream>
  #include <string>

  void print() {}

  template<typename Head, typename ...Tail>
  void print(const Head &head, const Tail &...tail) {
    std::cout << head;
    print(tail...);
  }

  int main() {
    std::string hello = "Hello";
    print(hello, ", world!", " ", 2011, '\n');
  }

llvm-svn: 123000
2011-01-07 16:43:16 +00:00
Douglas Gregor
3c6bd2ad38 Add Decl::isParameterPack(), which covers both function and template
parameter packs, along with ParmVarDecl::isParameterPack(), which
looks for function parameter packs. Use these routines to fix some
obvious FIXMEs.

llvm-svn: 122904
2011-01-05 21:11:38 +00:00
Douglas Gregor
eb29d18e5d Add semantic analysis for the creation of and an AST representation
for template template argument pack expansions. This allows fun such
as: 

  template<template<class> class ...> struct apply_impl { /*...*/ };
  template<template<class> class ...Metafunctions> struct apply {
    typedef typename apply_impl<Metafunctions...>::type type;
  };

However, neither template argument deduction nor template
instantiation is implemented for template template argument packs, so
this functionality isn't useful yet.

I'll probably replace the encoding of template template
argument pack expansions in TemplateArgument so that it's harder to
accidentally forget about the expansion. However, this is a step in
the right general direction.

llvm-svn: 122890
2011-01-05 17:40:24 +00:00
Douglas Gregor
f550077ef5 Implement support for template template parameter packs, e.g.,
template<template<class> class ...Metafunctions>
    struct apply_to_each;

llvm-svn: 122874
2011-01-05 15:48:55 +00:00
Douglas Gregor
820ba7ba43 Implement the sizeof...(pack) expression to compute the length of a
parameter pack.

Note that we're missing proper libclang support for the new
SizeOfPackExpr expression node.

llvm-svn: 122813
2011-01-04 17:33:58 +00:00
Douglas Gregor
752a595655 Implement pack expansions whose pattern is a base-specifier.
llvm-svn: 122782
2011-01-03 22:36:02 +00:00
Douglas Gregor
98318c2259 Properly rebuild pack expansions whose pattern is a non-type template
argument. As part of this, be more careful when determining if there
are any parameter packs that cannot be expanded.

llvm-svn: 122776
2011-01-03 21:37:45 +00:00
Douglas Gregor
1440693c50 Diagnose the presence of unexpanded parameter packs within class
template partial specialization arguments.

llvm-svn: 122769
2011-01-03 20:35:03 +00:00
Douglas Gregor
e8e9dd624c Implement support for pack expansions whose pattern is a non-type
template argument (described by an expression, of course). For
example:

  template<int...> struct int_tuple { };

  template<int ...Values>
  struct square {
    typedef int_tuple<(Values*Values)...> type;
  };

It also lays the foundation for pack expansions in an initializer-list.
  

llvm-svn: 122751
2011-01-03 17:17:50 +00:00
Douglas Gregor
eb5a39deb2 When instantiating a non-type template parameter pack, be sure to
extract the appropriate argument from the argument pack (based on the
current substitution index, of course). Simple instantiation of pack
expansions involving non-type template parameter packs now works.

llvm-svn: 122532
2010-12-24 00:15:10 +00:00
Douglas Gregor
da3cc0d3bf Add an AST representation for non-type template parameter
packs, e.g.,

  template<typename T, unsigned ...Dims> struct multi_array;

along with semantic analysis support for finding unexpanded non-type
template parameter packs in types, expressions, and so on.

Template instantiation involving non-type template parameter packs
probably doesn't work yet. That'll come soon.

llvm-svn: 122527
2010-12-23 23:51:58 +00:00
Douglas Gregor
27b4c16fef Implement parsing of function parameter packs and non-type template
parameter packs (C++0x [dcl.fct]p13), including disambiguation between
unnamed function parameter packs and varargs (C++0x [dcl.fct]p14) for
cases like 

  void f(T...)

where T may or may not contain unexpanded parameter packs.

llvm-svn: 122520
2010-12-23 22:44:42 +00:00
Douglas Gregor
0f3feb4e8d Implement template argument deduction for pack expansions whose
pattern is a template argument, which involves repeatedly deducing
template arguments using the pattern of the pack expansion, then
bundling the resulting deductions into an argument pack.

We can now handle a variety of simple list-handling metaprograms using
variadic templates. See, e.g., the new "count" metaprogram.

llvm-svn: 122439
2010-12-22 21:19:48 +00:00
Douglas Gregor
76aca7b2e8 Implement instantiation of pack expansions whose pattern is a type-id
in an exception specification.

llvm-svn: 122297
2010-12-21 00:52:54 +00:00
Douglas Gregor
15b4ec22f1 Give the RecursiveASTVisitor a configuration function
shouldWalkTypesOfTypeLocs() that determines whether it should walk the
Types within TypeLocs. This walk is redundant, but perhaps required
for some clients. Disabling this redundant walk in the unexpanded
parameter pack finder produces better results, because we get
parameter packs with source location info *unless* such source
location information isn't available.

llvm-svn: 122287
2010-12-20 23:07:20 +00:00
Douglas Gregor
840bd6cce5 Implement basic support for template instantiation of pack expansions
whose patterns are template arguments. We can now instantiate, e.g.,

  typedef tuple<pair<OuterTypes, InnerTypes>...> type;

where OuterTypes and InnerTypes are template type parameter packs.

There is a horrible inefficiency in
TemplateArgumentLoc::getPackExpansionPattern(), where we need to
create copies of TypeLoc data because our interfaces traffic in
TypeSourceInfo pointers where they should traffic in TypeLocs
instead. I've isolated in efficiency in this one routine; once we
refactor our interfaces to traffic in TypeLocs, we can eliminate it.

llvm-svn: 122278
2010-12-20 22:05:00 +00:00
Douglas Gregor
d2fa766ad0 Introduce a new type, PackExpansionType, to capture types that are
pack expansions, e.g. given

  template<typename... Types> struct tuple;

  template<typename... Types>
  struct tuple_of_refs {
    typedef tuple<Types&...> types;
  };

the type of the "types" typedef is a PackExpansionType whose pattern
is Types&. 

This commit introduces support for creating pack expansions for
template type arguments, as above, but not for any other kind of pack
expansion, nor for any form of instantiation.

llvm-svn: 122223
2010-12-20 02:24:11 +00:00
Douglas Gregor
062ecac8ed Tweak a comment
llvm-svn: 121979
2010-12-16 17:19:19 +00:00
Douglas Gregor
6ff1fbf65f Check for unexpanded parameter packs in default arguments.
llvm-svn: 121962
2010-12-16 08:48:57 +00:00
Douglas Gregor
6ab34afc4e Fix a regression I caused in r121930. It turns out that
DeclarationNameInfo instances don't always have a non-NULL
TypeSourceInfo?

llvm-svn: 121940
2010-12-16 01:40:04 +00:00
Douglas Gregor
c435653998 Check for unexpanded parameter packs in using declarations. As a
drive-by, make sure to check for unexpanded parameter packs within the
name of a declaration.

llvm-svn: 121930
2010-12-16 00:46:58 +00:00
Douglas Gregor
a8461bb439 Test that all of the relevant types properly compute the "contains
unexpanded parameter pack" bit and that the recursive AST visitor can
then find those unexpanded parameter packs.

llvm-svn: 121899
2010-12-15 21:57:59 +00:00
Douglas Gregor
1da294a9d6 Introduce a RecursiveASTVisitor subclass that finds all unexpanded
parameter packs within a statement, type, etc. Use this visitor to
provide improved diagnostics for the presence of unexpanded parameter
packs in a full expression, base type, declaration type, etc., by
highlighting the unexpanded parameter packs and providing their names,
e.g.,

test/CXX/temp/temp.decls/temp.variadic/p5.cpp:28:85: error: declaration type
      contains unexpanded parameter packs 'VeryInnerTypes',
      'OuterTypes', ...
  ...VeryInnerTypes, OuterTypes>, pair<InnerTypes, OuterTypes> > types;
     ~~~~~~~~~~~~~~  ~~~~~~~~~~        ~~~~~~~~~~  ~~~~~~~~~~    ^

llvm-svn: 121883
2010-12-15 19:43:21 +00:00
Douglas Gregor
b55fdf8c6f Move the work-in-progress implementation of variadic templates to its own file in Sema. No functionality change.
llvm-svn: 121869
2010-12-15 17:38:57 +00:00