If we end up instantiating a function parameter whose default argument

has not yet been parsed, note that the default argument hasn't been
parsed and keep track of all of the instantiations of that function
parameter. When its default argument does get parsed, imbue the
instantiations with that default argument. Fixes PR8245.

llvm-svn: 116324

2 files changed, 15 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index a27785e4f35..ec02f75ecbe 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -142,6 +142,18 @@ Sema::SetParamDefaultArgument(ParmVarDecl *Param, Expr *Arg,
   // Okay: add the default argument to the parameter
   Param->setDefaultArg(Arg);
 
+  // We have already instantiated this parameter; provide each of the 
+  // instantiations with the uninstantiated default argument.
+  UnparsedDefaultArgInstantiationsMap::iterator InstPos
+    = UnparsedDefaultArgInstantiations.find(Param);
+  if (InstPos != UnparsedDefaultArgInstantiations.end()) {
+    for (unsigned I = 0, N = InstPos->second.size(); I != N; ++I)
+      InstPos->second[I]->setUninstantiatedDefaultArg(Arg);
+    
+    // We're done tracking this parameter's instantiations.
+    UnparsedDefaultArgInstantiations.erase(InstPos);
+  }
+  
   return false;
 }
 
diff --git a/clang/lib/Sema/SemaTemplateInstantiate.cpp b/clang/lib/Sema/SemaTemplateInstantiate.cpp
index a2c3df653b7..98b8ccd8d85 100644
--- a/clang/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiate.cpp
@@ -1062,6 +1062,9 @@ ParmVarDecl *Sema::SubstParmVarDecl(ParmVarDecl *OldParm,
   if (OldParm->hasUninstantiatedDefaultArg()) {
     Expr *Arg = OldParm->getUninstantiatedDefaultArg();
     NewParm->setUninstantiatedDefaultArg(Arg);
+  } else if (OldParm->hasUnparsedDefaultArg()) {
+    NewParm->setUnparsedDefaultArg();
+    UnparsedDefaultArgInstantiations[OldParm].push_back(NewParm);
   } else if (Expr *Arg = OldParm->getDefaultArg())
     NewParm->setUninstantiatedDefaultArg(Arg);