1 files changed, 120 insertions, 2 deletions
diff --git a/include/clang/Sema/TemplateDeduction.h b/include/clang/Sema/TemplateDeduction.h
index 8292045..1daa689 100644
--- a/include/clang/Sema/TemplateDeduction.h
+++ b/include/clang/Sema/TemplateDeduction.h
@@ -20,6 +20,7 @@
 namespace clang {
 
 class TemplateArgumentList;
+class Sema;
 
 namespace sema {
 
@@ -162,7 +163,124 @@ public:
   Expr *Expression;
 };
 
-}
-}
+} // end namespace sema
+
+/// A structure used to record information about a failed
+/// template argument deduction, for diagnosis.
+struct DeductionFailureInfo {
+  /// A Sema::TemplateDeductionResult.
+  unsigned Result : 8;
+
+  /// \brief Indicates whether a diagnostic is stored in Diagnostic.
+  unsigned HasDiagnostic : 1;
+
+  /// \brief Opaque pointer containing additional data about
+  /// this deduction failure.
+  void *Data;
+
+  /// \brief A diagnostic indicating why deduction failed.
+  union {
+    void *Align;
+    char Diagnostic[sizeof(PartialDiagnosticAt)];
+  };
+
+  /// \brief Retrieve the diagnostic which caused this deduction failure,
+  /// if any.
+  PartialDiagnosticAt *getSFINAEDiagnostic();
+
+  /// \brief Retrieve the template parameter this deduction failure
+  /// refers to, if any.
+  TemplateParameter getTemplateParameter();
+
+  /// \brief Retrieve the template argument list associated with this
+  /// deduction failure, if any.
+  TemplateArgumentList *getTemplateArgumentList();
+
+  /// \brief Return the first template argument this deduction failure
+  /// refers to, if any.
+  const TemplateArgument *getFirstArg();
+
+  /// \brief Return the second template argument this deduction failure
+  /// refers to, if any.
+  const TemplateArgument *getSecondArg();
+
+  /// \brief Return the expression this deduction failure refers to,
+  /// if any.
+  Expr *getExpr();
+
+  /// \brief Free any memory associated with this deduction failure.
+  void Destroy();
+};
+
+/// TemplateSpecCandidate - This is a generalization of OverloadCandidate
+/// which keeps track of template argument deduction failure info, when
+/// handling explicit specializations (and instantiations) of templates
+/// beyond function overloading.
+/// For now, assume that the candidates are non-matching specializations.
+/// TODO: In the future, we may need to unify/generalize this with
+/// OverloadCandidate.
+struct TemplateSpecCandidate {
+  /// Specialization - The actual specialization that this candidate
+  /// represents. When NULL, this may be a built-in candidate.
+  Decl *Specialization;
+
+  /// Template argument deduction info
+  DeductionFailureInfo DeductionFailure;
+
+  void set(Decl *Spec, DeductionFailureInfo Info) {
+    Specialization = Spec;
+    DeductionFailure = Info;
+  }
+
+  /// Diagnose a template argument deduction failure.
+  void NoteDeductionFailure(Sema &S);
+};
+
+/// TemplateSpecCandidateSet - A set of generalized overload candidates,
+/// used in template specializations.
+/// TODO: In the future, we may need to unify/generalize this with
+/// OverloadCandidateSet.
+class TemplateSpecCandidateSet {
+  SmallVector<TemplateSpecCandidate, 16> Candidates;
+  SourceLocation Loc;
+
+  TemplateSpecCandidateSet(
+      const TemplateSpecCandidateSet &) LLVM_DELETED_FUNCTION;
+  void operator=(const TemplateSpecCandidateSet &) LLVM_DELETED_FUNCTION;
+
+  void destroyCandidates();
+
+public:
+  TemplateSpecCandidateSet(SourceLocation Loc) : Loc(Loc) {}
+  ~TemplateSpecCandidateSet() { destroyCandidates(); }
+
+  SourceLocation getLocation() const { return Loc; }
+
+  /// \brief Clear out all of the candidates.
+  /// TODO: This may be unnecessary.
+  void clear();
+
+  typedef SmallVector<TemplateSpecCandidate, 16>::iterator iterator;
+  iterator begin() { return Candidates.begin(); }
+  iterator end() { return Candidates.end(); }
+
+  size_t size() const { return Candidates.size(); }
+  bool empty() const { return Candidates.empty(); }
+
+  /// \brief Add a new candidate with NumConversions conversion sequence slots
+  /// to the overload set.
+  TemplateSpecCandidate &addCandidate() {
+    Candidates.push_back(TemplateSpecCandidate());
+    return Candidates.back();
+  }
+
+  void NoteCandidates(Sema &S, SourceLocation Loc);
+
+  void NoteCandidates(Sema &S, SourceLocation Loc) const {
+    const_cast<TemplateSpecCandidateSet *>(this)->NoteCandidates(S, Loc);
+  }
+};
+
+} // end namespace clang
 
 #endif