Sema: Preserve attributes on parameters in instantiated function templates.

This was causing correctness issues for ARC and the static analyzer when a
function template has "consumed" Objective-C object parameters (i.e.
parameters that will be released by the function before returning).

The fix is threefold:
(1) Actually copy over the attributes from old ParmVarDecls to new ones.
(2) Have Sema::BuildFunctionType only work for building FunctionProtoTypes,
    which it was doing anyway. This allows us to pass an ExtProtoInfo
    instead of a plain ExtInfo and several flags.
(3) Drop param attributes as part of StripImplicitInstantiation, which is
    used when an implicit instantiation is followed by an explicit one.

<rdar://problem/12685622>

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@176728 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 3 insertions, 1 deletions

diff --git a/lib/Sema/SemaTemplateInstantiate.cpp b/lib/Sema/SemaTemplateInstantiate.cpp
index 79e16f3942..255df80d66 100644
--- a/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/lib/Sema/SemaTemplateInstantiate.cpp
@@ -1716,7 +1716,9 @@ ParmVarDecl *Sema::SubstParmVarDecl(ParmVarDecl *OldParm,
 
   NewParm->setScopeInfo(OldParm->getFunctionScopeDepth(),
                         OldParm->getFunctionScopeIndex() + indexAdjustment);
-  
+
+  InstantiateAttrs(TemplateArgs, OldParm, NewParm);
+
   return NewParm;  
 }