Variadic templates: extend the Expr class with a bit that specifies

whether the expression contains an unexpanded parameter pack, in the
same vein as the changes to the Type hierarchy. Compute this bit
within all of the Expr subclasses.

This change required a bunch of reshuffling of dependency
calculations, mainly to consolidate them inside the constructors and
to fuse multiple loops that iterate over arguments to determine type
dependence, value dependence, and (now) containment of unexpanded
parameter packs.

Again, testing is painfully sparse, because all of the diagnostics
will change and it is more important to test the to-be-written visitor
that collects unexpanded parameter packs.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@121831 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 36 insertions, 0 deletions

diff --git a/lib/AST/TemplateBase.cpp b/lib/AST/TemplateBase.cpp
index ef2deea8c8..ead7885077 100644
--- a/lib/AST/TemplateBase.cpp
+++ b/lib/AST/TemplateBase.cpp
@@ -26,6 +26,42 @@ using namespace clang;
 // TemplateArgument Implementation
 //===----------------------------------------------------------------------===//
 
+bool TemplateArgument::isDependent() const {
+  switch (getKind()) {
+  case Null:
+    assert(false && "Should not have a NULL template argument");
+    return false;
+
+  case Type:
+    return getAsType()->isDependentType();
+
+  case Template:
+    return getAsTemplate().isDependent();
+      
+  case Declaration:
+    if (DeclContext *DC = dyn_cast<DeclContext>(getAsDecl()))
+      return DC->isDependentContext();
+    return getAsDecl()->getDeclContext()->isDependentContext();
+
+  case Integral:
+    // Never dependent
+    return false;
+
+  case Expression:
+    return (getAsExpr()->isTypeDependent() || getAsExpr()->isValueDependent());
+
+  case Pack:
+    for (pack_iterator P = pack_begin(), PEnd = pack_end(); P != PEnd; ++P) {
+      if (P->isDependent())
+        return true;
+    }
+
+    return false;
+  }
+
+  return false;
+}
+
 bool TemplateArgument::containsUnexpandedParameterPack() const {
   switch (getKind()) {
   case Null: