[llvm-commits] CVS: llvm/lib/Target/TargetData.cpp

[Chris Lattner]

Changes in directory llvm/lib/Target:

TargetData.cpp updated: 1.57 -> 1.58
---
Log message:

Implement a new InvalidateStructLayoutInfo method and add some comments


---
Diffs of the changes:  (+18 -0)

 TargetData.cpp |   18 ++++++++++++++++++
 1 files changed, 18 insertions(+)


Index: llvm/lib/Target/TargetData.cpp
diff -u llvm/lib/Target/TargetData.cpp:1.57 llvm/lib/Target/TargetData.cpp:1.58
--- llvm/lib/Target/TargetData.cpp:1.57	Tue Aug  2 14:25:02 2005
+++ llvm/lib/Target/TargetData.cpp	Fri Jan 13 18:07:34 2006
@@ -131,6 +131,9 @@
   BoolAlignment    = 1;
 }
 
+/// Layouts - The lazy cache of structure layout information maintained by
+/// TargetData.
+///
 static std::map<std::pair<const TargetData*,const StructType*>,
                 StructLayout> *Layouts = 0;
 
@@ -165,6 +168,21 @@
   }
 }
 
+/// InvalidateStructLayoutInfo - TargetData speculatively caches StructLayout
+/// objects.  If a TargetData object is alive when types are being refined and
+/// removed, this method must be called whenever a StructType is removed to
+/// avoid a dangling pointer in this cache.
+void TargetData::InvalidateStructLayoutInfo(const StructType *Ty) const {
+  if (!Layouts) return;  // No cache.
+
+  std::map<std::pair<const TargetData*,const StructType*>,
+           StructLayout>::iterator I = Layouts->find(std::make_pair(this, Ty));
+  if (I != Layouts->end())
+    Layouts->erase(I);
+}
+
+
+
 static inline void getTypeInfo(const Type *Ty, const TargetData *TD,
                                uint64_t &Size, unsigned char &Alignment) {
   assert(Ty->isSized() && "Cannot getTypeInfo() on a type that is unsized!");