Revert temporarily D29877 "Warn about unused static file scope function template declarations."

We need to address cases (breaking libc++) such as

template <class _Up> static int __test(...);

template<typename _Tp>
auto v = __test<_Tp>(0);

llvm-svn: 299956

1 files changed, 0 insertions, 14 deletions

diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp
index f943ab56507..294b56059b3 100644
--- a/clang/lib/Sema/Sema.cpp
+++ b/clang/lib/Sema/Sema.cpp
@@ -470,13 +470,6 @@ static bool ShouldRemoveFromUnused(Sema *SemaRef, const DeclaratorDecl *D) {
     return true;
 
   if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
-    // If this is a function template and none of its specializations is used,
-    // we should warn.
-    if (FunctionTemplateDecl *Template = FD->getDescribedFunctionTemplate())
-      for (const auto *Spec : Template->specializations())
-        if (ShouldRemoveFromUnused(SemaRef, Spec))
-          return true;
-
     // UnusedFileScopedDecls stores the first declaration.
     // The declaration may have become definition so check again.
     const FunctionDecl *DeclToCheck;
@@ -500,13 +493,6 @@ static bool ShouldRemoveFromUnused(Sema *SemaRef, const DeclaratorDecl *D) {
         VD->isUsableInConstantExpressions(SemaRef->Context))
       return true;
 
-    if (VarTemplateDecl *Template = VD->getDescribedVarTemplate())
-      // If this is a variable template and none of its specializations is used,
-      // we should warn.
-      for (const auto *Spec : Template->specializations())
-        if (ShouldRemoveFromUnused(SemaRef, Spec))
-          return true;
-
     // UnusedFileScopedDecls stores the first declaration.
     // The declaration may have become definition so check again.
     const VarDecl *DeclToCheck = VD->getDefinition();