From 27684ae66d5545f211c0ac4393d0ba2bf3b5b47c Mon Sep 17 00:00:00 2001
From: Aaron Puchert <aaronpuchert@alice-dsl.net>
Date: Sat, 1 Feb 2020 00:05:36 +0100
Subject: [PATCH] Don't warn about missing declarations for partial template
 specializations

Summary: Just like templates, they are excepted from the ODR rule.

Reviewed By: aaron.ballman, rsmith

Differential Revision: https://reviews.llvm.org/D68923
---
 clang/lib/Sema/SemaDecl.cpp                               | 1 +
 clang/test/SemaCXX/warn-missing-variable-declarations.cpp | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index e8589d3bcf4..2175361dab9 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -12523,6 +12523,7 @@ void Sema::CheckCompleteVariableDeclaration(VarDecl *var) {
       var->getDeclContext()->getRedeclContext()->isFileContext() &&
       var->isExternallyVisible() && var->hasLinkage() &&
       !var->isInline() && !var->getDescribedVarTemplate() &&
+      !isa<VarTemplatePartialSpecializationDecl>(var) &&
       !isTemplateInstantiation(var->getTemplateSpecializationKind()) &&
       !getDiagnostics().isIgnored(diag::warn_missing_variable_declarations,
                                   var->getLocation())) {
diff --git a/clang/test/SemaCXX/warn-missing-variable-declarations.cpp b/clang/test/SemaCXX/warn-missing-variable-declarations.cpp
index e2480fd663b..b50eeed30e7 100644
--- a/clang/test/SemaCXX/warn-missing-variable-declarations.cpp
+++ b/clang/test/SemaCXX/warn-missing-variable-declarations.cpp
@@ -70,6 +70,8 @@ template<typename> int var_template = 0;
 template<typename> constexpr int const_var_template = 0;
 template<typename> static int static_var_template = 0;
 
+template<typename T> int var_template<T*>;
+
 template int var_template<int[1]>;
 int use_var_template() { return var_template<int[2]>; }
 template int var_template<int[3]>;
-- 
2.11.0