Implement basic support for the use of variadic templates and blocks

together. In particular: 
  - Handle the use of captured parameter pack names within blocks
  (BlockDeclRefExpr understands parameter packs now)
  - Handle the declaration and expansion of parameter packs within a block's
  parameter list, e.g., ^(Args ...args) { ... })
  - Handle instantiation of blocks where the return type was not
  explicitly specified. (unrelated, but necessary for my tests).

Together, these fixes should make blocks and variadic templates work
reasonably well together. Note that BlockDeclRefExpr is still broken
w.r.t. its computation of type and value dependence, which will still
cause problems for blocks in templates.

llvm-svn: 123849

1 files changed, 10 insertions, 1 deletions

diff --git a/clang/lib/Sema/SemaTemplateVariadic.cpp b/clang/lib/Sema/SemaTemplateVariadic.cpp
index 38a777efb17..3f76d9f6e31 100644
--- a/clang/lib/Sema/SemaTemplateVariadic.cpp
+++ b/clang/lib/Sema/SemaTemplateVariadic.cpp
@@ -64,7 +64,7 @@ namespace {
       return true;
     }
 
-    /// \brief Record occurrences of (FIXME: function and) non-type template
+    /// \brief Record occurrences of function and non-type template
     /// parameter packs in an expression.
     bool VisitDeclRefExpr(DeclRefExpr *E) {
       if (E->getDecl()->isParameterPack())
@@ -73,6 +73,15 @@ namespace {
       return true;
     }
     
+    // \brief Record occurrences of function and non-type template parameter
+    // packs in a block-captured expression.
+    bool VisitBlockDeclRefExpr(BlockDeclRefExpr *E) {
+      if (E->getDecl()->isParameterPack())
+        Unexpanded.push_back(std::make_pair(E->getDecl(), E->getLocation()));
+      
+      return true;
+    }
+    
     /// \brief Record occurrences of template template parameter packs.
     bool TraverseTemplateName(TemplateName Template) {
       if (TemplateTemplateParmDecl *TTP