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, 8 insertions, 5 deletions

diff --git a/lib/VMCore/ConstantFold.h b/lib/VMCore/ConstantFold.h
index 49aea11870..66ca8ff31a 100644
--- a/lib/VMCore/ConstantFold.h
+++ b/lib/VMCore/ConstantFold.h
@@ -28,11 +28,13 @@ namespace llvm {
   Constant *ConstantFoldCastInstruction(
     unsigned opcode,     ///< The opcode of the cast
     const Constant *V,   ///< The source constant
-    const Type *DestTy   ///< The destination type
+    const Type *DestTy,   ///< The destination type
+    bool locked = true
   );
   Constant *ConstantFoldSelectInstruction(const Constant *Cond,
                                           const Constant *V1,
-                                          const Constant *V2);
+                                          const Constant *V2,
+                                          bool locked = true);
   Constant *ConstantFoldExtractElementInstruction(const Constant *Val,
                                                   const Constant *Idx);
   Constant *ConstantFoldInsertElementInstruction(const Constant *Val,
@@ -49,12 +51,13 @@ namespace llvm {
                                                const unsigned* Idxs,
                                                unsigned NumIdx);
   Constant *ConstantFoldBinaryInstruction(unsigned Opcode, const Constant *V1,
-                                          const Constant *V2);
+                                          const Constant *V2,
+                                          bool locked = true);
   Constant *ConstantFoldCompareInstruction(unsigned short predicate, 
                                            const Constant *C1, 
                                            const Constant *C2);
-  Constant *ConstantFoldGetElementPtr(const Constant *C,
-                                      Constant* const *Idxs, unsigned NumIdx);
+  Constant *ConstantFoldGetElementPtr(const Constant *C, Constant* const *Idxs,
+                                      unsigned NumIdx, bool locked = true);
 } // End llvm namespace
 
 #endif