5 files changed, 26 insertions, 17 deletions

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index a2c3c2e1472..b3cbbf203e2 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -2953,12 +2953,22 @@ void Sema::MergeVarDecl(VarDecl *New, LookupResult &Previous,
     return New->setInvalidDecl();
   }
 
-  if (New->isThreadSpecified() && !Old->isThreadSpecified()) {
-    Diag(New->getLocation(), diag::err_thread_non_thread) << New->getDeclName();
-    Diag(Old->getLocation(), diag::note_previous_definition);
-  } else if (!New->isThreadSpecified() && Old->isThreadSpecified()) {
-    Diag(New->getLocation(), diag::err_non_thread_thread) << New->getDeclName();
-    Diag(Old->getLocation(), diag::note_previous_definition);
+  if (New->getTLSKind() != Old->getTLSKind()) {
+    if (!Old->getTLSKind()) {
+      Diag(New->getLocation(), diag::err_thread_non_thread) << New->getDeclName();
+      Diag(Old->getLocation(), diag::note_previous_declaration);
+    } else if (!New->getTLSKind()) {
+      Diag(New->getLocation(), diag::err_non_thread_thread) << New->getDeclName();
+      Diag(Old->getLocation(), diag::note_previous_declaration);
+    } else {
+      // Do not allow redeclaration to change the variable between requiring
+      // static and dynamic initialization.
+      // FIXME: GCC allows this, but uses the TLS keyword on the first
+      // declaration to determine the kind. Do we need to be compatible here?
+      Diag(New->getLocation(), diag::err_thread_thread_different_kind)
+        << New->getDeclName() << (New->getTLSKind() == VarDecl::TLS_Dynamic);
+      Diag(Old->getLocation(), diag::note_previous_declaration);
+    }
   }
 
   // C++ doesn't have tentative definitions, so go right ahead and check here.
@@ -4577,7 +4587,7 @@ bool Sema::inferObjCARCLifetime(ValueDecl *decl) {
   if (VarDecl *var = dyn_cast<VarDecl>(decl)) {
     // Thread-local variables cannot have lifetime.
     if (lifetime && lifetime != Qualifiers::OCL_ExplicitNone &&
-        var->isThreadSpecified()) {
+        var->getTLSKind()) {
       Diag(var->getLocation(), diag::err_arc_thread_ownership)
         << var->getType();
       return true;
@@ -4851,9 +4861,9 @@ Sema::ActOnVariableDeclarator(Scope *S, Declarator &D, DeclContext *DC,
       Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(),
            diag::err_thread_unsupported);
     else
-      // FIXME: Track which thread specifier was used; they have different
-      // semantics.
-      NewVD->setThreadSpecified(true);
+      NewVD->setTLSKind(TSCS == DeclSpec::TSCS_thread_local
+                          ? VarDecl::TLS_Dynamic
+                          : VarDecl::TLS_Static);
   }
 
   // C99 6.7.4p3
diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index f832809b2df..1fc1a7cc488 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -284,7 +284,7 @@ static bool mayBeSharedVariable(const Decl *D) {
   if (isa<FieldDecl>(D))
     return true;
   if (const VarDecl *vd = dyn_cast<VarDecl>(D))
-    return (vd->hasGlobalStorage() && !(vd->isThreadSpecified()));
+    return vd->hasGlobalStorage() && !vd->getTLSKind();
 
   return false;
 }
@@ -1656,7 +1656,7 @@ static void handleTLSModelAttr(Sema &S, Decl *D,
     return;
   }
 
-  if (!isa<VarDecl>(D) || !cast<VarDecl>(D)->isThreadSpecified()) {
+  if (!isa<VarDecl>(D) || !cast<VarDecl>(D)->getTLSKind()) {
     S.Diag(Attr.getLoc(), diag::err_attribute_wrong_decl_type)
       << Attr.getName() << ExpectedTLSVar;
     return;
diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
index b8acb2d7310..c815d4f9abc 100644
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -165,8 +165,8 @@ OMPThreadPrivateDecl *Sema::CheckOMPThreadPrivateDecl(
       continue;
     }
 
-    // Check if threadspecified is set.
-    if (VD->isThreadSpecified()) {
+    // Check if this is a TLS variable.
+    if (VD->getTLSKind()) {
       Diag(ILoc, diag::err_omp_var_thread_local) << VD;
       Diag(VD->getLocation(), diag::note_forward_declaration) << VD;
       continue;
diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
index 990626189e1..ae091e3da34 100644
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -3842,8 +3842,7 @@ CheckTemplateArgumentAddressOfObjectOrFunction(Sema &S,
     }
 
     // A template argument must have static storage duration.
-    // FIXME: Ensure this works for thread_local as well as __thread.
-    if (Var->isThreadSpecified()) {
+    if (Var->getTLSKind()) {
       S.Diag(Arg->getLocStart(), diag::err_template_arg_thread_local)
         << Arg->getSourceRange();
       S.Diag(Var->getLocation(), diag::note_template_arg_refers_here);
diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 17e3218bffc..868369e87cd 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -339,7 +339,7 @@ Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D) {
                                  D->getLocation(), D->getIdentifier(),
                                  DI->getType(), DI,
                                  D->getStorageClass());
-  Var->setThreadSpecified(D->isThreadSpecified());
+  Var->setTLSKind(D->getTLSKind());
   Var->setInitStyle(D->getInitStyle());
   Var->setCXXForRangeDecl(D->isCXXForRangeDecl());
   Var->setConstexpr(D->isConstexpr());