Fix template instantiation of attributes. More specifically, fix the case

where an attribute is attached to a forward declaration of a template function,
and refers to parameters of that declaration, but is then inherited by the
definition of that function.  When the definition is instantiated, the
parameter references need to be remapped.

llvm-svn: 164710

1 files changed, 20 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaTemplateInstantiate.cpp b/clang/lib/Sema/SemaTemplateInstantiate.cpp
index 621f92bb676..665dd07b8f8 100644
--- a/clang/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiate.cpp
@@ -2635,8 +2635,25 @@ bool Sema::Subst(const TemplateArgumentLoc *Args, unsigned NumArgs,
   return Instantiator.TransformTemplateArguments(Args, NumArgs, Result);
 }
 
+
+static const Decl* getCanonicalParmVarDecl(const Decl *D) {
+  // When storing ParmVarDecls in the local instantiation scope, we always
+  // want to use the ParmVarDecl from the canonical function declaration,
+  // since the map is then valid for any redeclaration or definition of that
+  // function.
+  if (const ParmVarDecl *PV = dyn_cast<ParmVarDecl>(D)) {
+    if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(PV->getDeclContext())) {
+      unsigned i = PV->getFunctionScopeIndex();
+      return FD->getCanonicalDecl()->getParamDecl(i);
+    }
+  }
+  return D;
+}
+
+
 llvm::PointerUnion<Decl *, LocalInstantiationScope::DeclArgumentPack *> *
 LocalInstantiationScope::findInstantiationOf(const Decl *D) {
+  D = getCanonicalParmVarDecl(D);
   for (LocalInstantiationScope *Current = this; Current;
        Current = Current->Outer) {
 
@@ -2668,6 +2685,7 @@ LocalInstantiationScope::findInstantiationOf(const Decl *D) {
 }
 
 void LocalInstantiationScope::InstantiatedLocal(const Decl *D, Decl *Inst) {
+  D = getCanonicalParmVarDecl(D);
   llvm::PointerUnion<Decl *, DeclArgumentPack *> &Stored = LocalDecls[D];
   if (Stored.isNull())
     Stored = Inst;
@@ -2680,11 +2698,13 @@ void LocalInstantiationScope::InstantiatedLocal(const Decl *D, Decl *Inst) {
 
 void LocalInstantiationScope::InstantiatedLocalPackArg(const Decl *D, 
                                                        Decl *Inst) {
+  D = getCanonicalParmVarDecl(D);
   DeclArgumentPack *Pack = LocalDecls[D].get<DeclArgumentPack *>();
   Pack->push_back(Inst);
 }
 
 void LocalInstantiationScope::MakeInstantiatedLocalArgPack(const Decl *D) {
+  D = getCanonicalParmVarDecl(D);
   llvm::PointerUnion<Decl *, DeclArgumentPack *> &Stored = LocalDecls[D];
   assert(Stored.isNull() && "Already instantiated this local");
   DeclArgumentPack *Pack = new DeclArgumentPack;