Implement DR1454. This allows all intermediate results in constant expressions

to be core constant expressions (including pointers and references to
temporaries), and makes constexpr calculations Turing-complete. A Turing machine
simulator is included as a testcase.

This opens up the possibilty of removing CCValue entirely, and removing some
copies from the constant evaluator in the process, but that cleanup is not part
of this change.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@150557 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 9 insertions, 6 deletions

diff --git a/include/clang/AST/APValue.h b/include/clang/AST/APValue.h
index f361f0f5c8..f687fb7beb 100644
--- a/include/clang/AST/APValue.h
+++ b/include/clang/AST/APValue.h
@@ -138,14 +138,14 @@ public:
   APValue(const APValue &RHS) : Kind(Uninitialized) {
     *this = RHS;
   }
-  APValue(LValueBase B, const CharUnits &O, NoLValuePath N)
+  APValue(LValueBase B, const CharUnits &O, NoLValuePath N, unsigned CallIndex)
       : Kind(Uninitialized) {
-    MakeLValue(); setLValue(B, O, N);
+    MakeLValue(); setLValue(B, O, N, CallIndex);
   }
   APValue(LValueBase B, const CharUnits &O, ArrayRef<LValuePathEntry> Path,
-          bool OnePastTheEnd)
+          bool OnePastTheEnd, unsigned CallIndex)
       : Kind(Uninitialized) {
-    MakeLValue(); setLValue(B, O, Path, OnePastTheEnd);
+    MakeLValue(); setLValue(B, O, Path, OnePastTheEnd, CallIndex);
   }
   APValue(UninitArray, unsigned InitElts, unsigned Size) : Kind(Uninitialized) {
     MakeArray(InitElts, Size);
@@ -246,6 +246,7 @@ public:
   bool isLValueOnePastTheEnd() const;
   bool hasLValuePath() const;
   ArrayRef<LValuePathEntry> getLValuePath() const;
+  unsigned getLValueCallIndex() const;
 
   APValue &getVectorElt(unsigned I) {
     assert(isVector() && "Invalid accessor");
@@ -365,9 +366,11 @@ public:
     ((ComplexAPFloat*)(char*)Data)->Real = R;
     ((ComplexAPFloat*)(char*)Data)->Imag = I;
   }
-  void setLValue(LValueBase B, const CharUnits &O, NoLValuePath);
+  void setLValue(LValueBase B, const CharUnits &O, NoLValuePath,
+                 unsigned CallIndex);
   void setLValue(LValueBase B, const CharUnits &O,
-                 ArrayRef<LValuePathEntry> Path, bool OnePastTheEnd);
+                 ArrayRef<LValuePathEntry> Path, bool OnePastTheEnd,
+                 unsigned CallIndex);
   void setUnion(const FieldDecl *Field, const APValue &Value) {
     assert(isUnion() && "Invalid accessor");
     ((UnionData*)(char*)Data)->Field = Field;