1 files changed, 28 insertions, 2 deletions
diff --git a/contrib/llvm/tools/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/contrib/llvm/tools/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index d8af8f34530b..ab68e7e671de 100644
--- a/contrib/llvm/tools/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/contrib/llvm/tools/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -3729,6 +3729,30 @@ TemplateDeclInstantiator::InitMethodInstantiation(CXXMethodDecl *New,
   return false;
 }
 
+/// Instantiate (or find existing instantiation of) a function template with a
+/// given set of template arguments.
+///
+/// Usually this should not be used, and template argument deduction should be
+/// used in its place.
+FunctionDecl *
+Sema::InstantiateFunctionDeclaration(FunctionTemplateDecl *FTD,
+                                     const TemplateArgumentList *Args,
+                                     SourceLocation Loc) {
+  FunctionDecl *FD = FTD->getTemplatedDecl();
+
+  sema::TemplateDeductionInfo Info(Loc);
+  InstantiatingTemplate Inst(
+      *this, Loc, FTD, Args->asArray(),
+      CodeSynthesisContext::ExplicitTemplateArgumentSubstitution, Info);
+  if (Inst.isInvalid())
+    return nullptr;
+
+  ContextRAII SavedContext(*this, FD);
+  MultiLevelTemplateArgumentList MArgs(*Args);
+
+  return cast_or_null<FunctionDecl>(SubstDecl(FD, FD->getParent(), MArgs));
+}
+
 /// In the MS ABI, we need to instantiate default arguments of dllexported
 /// default constructors along with the constructor definition. This allows IR
 /// gen to emit a constructor closure which calls the default constructor with
@@ -3812,7 +3836,8 @@ void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
       PendingInstantiations.push_back(
         std::make_pair(Function, PointOfInstantiation));
     } else if (TSK == TSK_ImplicitInstantiation) {
-      if (AtEndOfTU && !getDiagnostics().hasErrorOccurred()) {
+      if (AtEndOfTU && !getDiagnostics().hasErrorOccurred() &&
+          !getSourceManager().isInSystemHeader(PatternDecl->getLocStart())) {
         Diag(PointOfInstantiation, diag::warn_func_template_missing)
           << Function;
         Diag(PatternDecl->getLocation(), diag::note_forward_template_decl);
@@ -4347,7 +4372,8 @@ void Sema::InstantiateVariableDefinition(SourceLocation PointOfInstantiation,
         std::make_pair(Var, PointOfInstantiation));
     } else if (TSK == TSK_ImplicitInstantiation) {
       // Warn about missing definition at the end of translation unit.
-      if (AtEndOfTU && !getDiagnostics().hasErrorOccurred()) {
+      if (AtEndOfTU && !getDiagnostics().hasErrorOccurred() &&
+          !getSourceManager().isInSystemHeader(PatternDecl->getLocStart())) {
         Diag(PointOfInstantiation, diag::warn_var_template_missing)
           << Var;
         Diag(PatternDecl->getLocation(), diag::note_forward_template_decl);