From b2f81cf7f8445e0c65c0428f4fbb0442566916b8 Mon Sep 17 00:00:00 2001
From: Douglas Gregor <dgregor@apple.com>
Date: Thu, 1 Oct 2009 23:51:25 +0000
Subject: [PATCH] Make sure to free the explicit template arguments provided
 for an explicit instantiation. Also, tighten up reference-count checking to
 help catch these issues earlier. Fixes PR5069.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@83225 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/clang/AST/Stmt.h                     | 5 ++++-
 lib/Sema/SemaTemplate.cpp                    | 1 +
 test/SemaTemplate/explicit-instantiation.cpp | 4 ++++
 3 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/include/clang/AST/Stmt.h b/include/clang/AST/Stmt.h
index 125279c1ed..411f215e91 100644
--- a/include/clang/AST/Stmt.h
+++ b/include/clang/AST/Stmt.h
@@ -188,7 +188,10 @@ public:
     return this;
   }
 
-  StmtClass getStmtClass() const { return (StmtClass)sClass; }
+  StmtClass getStmtClass() const { 
+    assert(RefCount >= 1 && "Referencing already-destroyed statement!");
+    return (StmtClass)sClass; 
+  }
   const char *getStmtClassName() const;
 
   /// SourceLocation tokens are not useful in isolation - they are low level
diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
index c7ce032594..d12ec9318a 100644
--- a/lib/Sema/SemaTemplate.cpp
+++ b/lib/Sema/SemaTemplate.cpp
@@ -3414,6 +3414,7 @@ Sema::DeclResult Sema::ActOnExplicitInstantiation(Scope *S,
                                TemplateId->getTemplateArgLocations(),
                                TemplateArgs);
     HasExplicitTemplateArgs = true;
+    TemplateArgsPtr.release();
   }
     
   // C++ [temp.explicit]p1:
diff --git a/test/SemaTemplate/explicit-instantiation.cpp b/test/SemaTemplate/explicit-instantiation.cpp
index 07994f97d3..b9a4ad282b 100644
--- a/test/SemaTemplate/explicit-instantiation.cpp
+++ b/test/SemaTemplate/explicit-instantiation.cpp
@@ -69,3 +69,7 @@ template void print_type<int>(float*); // expected-error{{does not refer}}
 
 void print_type(double*);
 template void print_type<double>(double*);
+
+// PR5069
+template<int I> void foo0 (int (&)[I + 1]) { }
+template void foo0<2> (int (&)[3]);