From: Richard Smith <richard-llvm@metafoo.co.uk>
Date: Wed, 29 Apr 2015 00:07:09 +0000 (+0000)
Subject: PR20625: Instantiate static constexpr member function of a local struct in a function... 
X-Git-Tag: llvmorg-3.7.0-rc1~5776
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=180b92168dd61c0d6c61eaa241c3c21bd892a19b;p=platform%2Fupstream%2Fllvm.git

PR20625: Instantiate static constexpr member function of a local struct in a function template earlier.

This is necessary in order to allow the use of a constexpr member function, or
a member function with deduced return type, of a local class within a
surrounding instantiated function template specialization.

Patch by Michael Park!

llvm-svn: 236063
---

diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 8f2e95a..57faa1c 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -1302,11 +1302,19 @@ Decl *TemplateDeclInstantiator::VisitCXXRecordDecl(CXXRecordDecl *D) {
   // DR1484 clarifies that the members of a local class are instantiated as part
   // of the instantiation of their enclosing entity.
   if (D->isCompleteDefinition() && D->isLocalClass()) {
+    Sema::SavePendingLocalImplicitInstantiationsRAII
+        SavedPendingLocalImplicitInstantiations(SemaRef);
+
     SemaRef.InstantiateClass(D->getLocation(), Record, D, TemplateArgs,
                              TSK_ImplicitInstantiation,
                              /*Complain=*/true);
+
     SemaRef.InstantiateClassMembers(D->getLocation(), Record, TemplateArgs,
                                     TSK_ImplicitInstantiation);
+
+    // This class may have local implicit instantiations that need to be
+    // performed within this scope.
+    SemaRef.PerformPendingInstantiations(/*LocalOnly=*/true);
   }
 
   SemaRef.DiagnoseUnusedNestedTypedefs(Record);
diff --git a/clang/test/SemaTemplate/instantiate-local-class.cpp b/clang/test/SemaTemplate/instantiate-local-class.cpp
index 367134a..668fb6f 100644
--- a/clang/test/SemaTemplate/instantiate-local-class.cpp
+++ b/clang/test/SemaTemplate/instantiate-local-class.cpp
@@ -213,3 +213,16 @@ namespace PR23194 {
     return make_seed_pair();
   }
 }
+
+namespace PR20625 {
+template <typename T>
+void f() {
+  struct N {
+    static constexpr int get() { return 42; }
+  };
+  constexpr int n = N::get();
+  static_assert(n == 42, "n == 42");
+}
+
+void g() { f<void>(); }
+}