Implement the last bullet of [temp.deduct.type]p5 and part of the last

sentence of [temp.deduct.call]p1, both of which concern the
non-deducibility of parameter packs not at the end of a
parameter-type-list. The latter isn't fully implemented yet; see the
new FIXME.

llvm-svn: 123210

1 files changed, 13 insertions, 0 deletions

diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index 24fc45f4be1..786f28a60da 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -1444,6 +1444,9 @@ void FunctionDecl::setParams(ASTContext &C,
 /// function parameters, if some of the parameters have default
 /// arguments (in C++) or the last parameter is a parameter pack.
 unsigned FunctionDecl::getMinRequiredArguments() const {
+  if (!getASTContext().getLangOptions().CPlusPlus)
+    return getNumParams();
+  
   unsigned NumRequiredArgs = getNumParams();  
   
   // If the last parameter is a parameter pack, we don't need an argument for 
@@ -1458,6 +1461,16 @@ unsigned FunctionDecl::getMinRequiredArguments() const {
          getParamDecl(NumRequiredArgs-1)->hasDefaultArg())
     --NumRequiredArgs;
 
+  // We might have parameter packs before the end. These can't be deduced,
+  // but they can still handle multiple arguments.
+  unsigned ArgIdx = NumRequiredArgs;
+  while (ArgIdx > 0) {
+    if (getParamDecl(ArgIdx - 1)->isParameterPack())
+      NumRequiredArgs = ArgIdx;
+    
+    --ArgIdx;
+  }
+  
   return NumRequiredArgs;
 }