Fix a serious bug that would cause deadlock during abstract type refinement. The constant creation

gets involved, and we end up trying to recursively acquire a writer lock.  The fix for this is slightly horrible,
and involves passing a boolean "locked" parameter around in Constants.cpp, but it's better than having locked and
unlocked versions of most of the code.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73790 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 4 insertions, 2 deletions

diff --git a/include/llvm/Constant.h b/include/llvm/Constant.h
index d4949d1a0f..613e24ca15 100644
--- a/include/llvm/Constant.h
+++ b/include/llvm/Constant.h
@@ -61,7 +61,7 @@ protected:
 public:
   /// Static constructor to get a '0' constant of arbitrary type...
   ///
-  static Constant *getNullValue(const Type *Ty);
+  static Constant *getNullValue(const Type *Ty, bool locked = true);
 
   /// Static constructor to get a '-1' constant.  This supports integers and
   /// vectors.
@@ -107,7 +107,9 @@ public:
   /// available cached constants.  Implementations should call
   /// destroyConstantImpl as the last thing they do, to destroy all users and
   /// delete this.
-  virtual void destroyConstant() { assert(0 && "Not reached!"); }
+  virtual void destroyConstant(bool locked = true) {
+    assert(0 && "Not reached!");
+  }
 
   //// Methods for support type inquiry through isa, cast, and dyn_cast:
   static inline bool classof(const Constant *) { return true; }