r209774 - Thread Safety Analysis: update TIL traversal mechanism to allow arbitrary

DeLesley Hutchins delesley at google.com
Wed May 28 14:28:14 PDT 2014


Author: delesley
Date: Wed May 28 16:28:13 2014
New Revision: 209774

URL: http://llvm.org/viewvc/llvm-project?rev=209774&view=rev
Log:
Thread Safety Analysis: update TIL traversal mechanism to allow arbitrary
local contexts.  Also includes some minor refactoring.

Modified:
    cfe/trunk/include/clang/Analysis/Analyses/ThreadSafetyCommon.h
    cfe/trunk/include/clang/Analysis/Analyses/ThreadSafetyOps.def
    cfe/trunk/include/clang/Analysis/Analyses/ThreadSafetyTIL.h
    cfe/trunk/include/clang/Analysis/Analyses/ThreadSafetyTraverse.h
    cfe/trunk/include/clang/Analysis/Analyses/ThreadSafetyUtil.h
    cfe/trunk/lib/Analysis/ThreadSafetyCommon.cpp
    cfe/trunk/lib/Analysis/ThreadSafetyTIL.cpp

Modified: cfe/trunk/include/clang/Analysis/Analyses/ThreadSafetyCommon.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Analysis/Analyses/ThreadSafetyCommon.h?rev=209774&r1=209773&r2=209774&view=diff
==============================================================================
--- cfe/trunk/include/clang/Analysis/Analyses/ThreadSafetyCommon.h (original)
+++ cfe/trunk/include/clang/Analysis/Analyses/ThreadSafetyCommon.h Wed May 28 16:28:13 2014
@@ -238,7 +238,7 @@ public:
       : Arena(A), SelfVar(nullptr), Scfg(nullptr), CurrentBB(nullptr),
         CurrentBlockInfo(nullptr) {
     // FIXME: we don't always have a self-variable.
-    SelfVar = new (Arena) til::Variable();
+    SelfVar = new (Arena) til::Variable(nullptr);
     SelfVar->setKind(til::Variable::VK_SFun);
   }
 

Modified: cfe/trunk/include/clang/Analysis/Analyses/ThreadSafetyOps.def
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Analysis/Analyses/ThreadSafetyOps.def?rev=209774&r1=209773&r2=209774&view=diff
==============================================================================
--- cfe/trunk/include/clang/Analysis/Analyses/ThreadSafetyOps.def (original)
+++ cfe/trunk/include/clang/Analysis/Analyses/ThreadSafetyOps.def Wed May 28 16:28:13 2014
@@ -34,7 +34,7 @@ TIL_OPCODE_DEF(Call)
 TIL_OPCODE_DEF(Alloc)
 TIL_OPCODE_DEF(Load)
 TIL_OPCODE_DEF(Store)
-TIL_OPCODE_DEF(ArrayFirst)
+TIL_OPCODE_DEF(ArrayIndex)
 TIL_OPCODE_DEF(ArrayAdd)
 
 TIL_OPCODE_DEF(UnaryOp)
@@ -42,6 +42,7 @@ TIL_OPCODE_DEF(BinaryOp)
 TIL_OPCODE_DEF(Cast)
 
 TIL_OPCODE_DEF(SCFG)
+TIL_OPCODE_DEF(BasicBlock)
 TIL_OPCODE_DEF(Phi)
 TIL_OPCODE_DEF(Goto)
 TIL_OPCODE_DEF(Branch)

Modified: cfe/trunk/include/clang/Analysis/Analyses/ThreadSafetyTIL.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Analysis/Analyses/ThreadSafetyTIL.h?rev=209774&r1=209773&r2=209774&view=diff
==============================================================================
--- cfe/trunk/include/clang/Analysis/Analyses/ThreadSafetyTIL.h (original)
+++ cfe/trunk/include/clang/Analysis/Analyses/ThreadSafetyTIL.h Wed May 28 16:28:13 2014
@@ -246,13 +246,6 @@ inline ValueType ValueType::getValueType
 
 
 
-enum TraversalKind {
-  TRV_Normal,
-  TRV_Lazy, // subexpression may need to be traversed lazily
-  TRV_Tail  // subexpression occurs in a tail position
-};
-
-
 // Base class for AST nodes in the typed intermediate language.
 class SExpr {
 public:
@@ -264,8 +257,9 @@ public:
   //   copy constructor: construct copy of E, with some additional arguments.
   // }
   //
-  // template <class V> typename V::R_SExpr traverse(V &Visitor) {
-  //   traverse all subexpressions, following the traversal/rewriter interface
+  // template <class V>
+  // typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
+  //   traverse all subexpressions, following the traversal/rewriter interface.
   // }
   //
   // template <class C> typename C::CType compare(CType* E, C& Cmp) {
@@ -375,8 +369,8 @@ public:
   };
 
   // These are defined after SExprRef contructor, below
+  inline Variable(SExpr *D, const clang::ValueDecl *Cvd = nullptr);
   inline Variable(StringRef s, SExpr *D = nullptr);
-  inline Variable(SExpr *D = nullptr, const clang::ValueDecl *Cvd = nullptr);
   inline Variable(const Variable &Vd, SExpr *D);
 
   VariableKind kind() const { return static_cast<VariableKind>(Flags); }
@@ -402,9 +396,10 @@ public:
   void setDefinition(SExpr *E);
   void setKind(VariableKind K) { Flags = K; }
 
-  template <class V> typename V::R_SExpr traverse(V &Visitor) {
+  template <class V>
+  typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
     // This routine is only called for variable references.
-    return Visitor.reduceVariableRef(this);
+    return Vs.reduceVariableRef(this);
   }
 
   template <class C> typename C::CType compare(Variable* E, C& Cmp) {
@@ -474,9 +469,10 @@ public:
     }
   }
 
-  template <class V> typename V::R_SExpr traverse(V &Visitor) {
+  template <class V>
+  typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
     assert(Result && "Cannot traverse Future that has not been forced.");
-    return Visitor.traverse(Result);
+    return Vs.traverse(Result, Ctx);
   }
 
   template <class C> typename C::CType compare(Future* E, C& Cmp) {
@@ -568,8 +564,9 @@ public:
   Undefined(const clang::Stmt *S = nullptr) : SExpr(COP_Undefined), Cstmt(S) {}
   Undefined(const Undefined &U) : SExpr(U), Cstmt(U.Cstmt) {}
 
-  template <class V> typename V::R_SExpr traverse(V &Visitor) {
-    return Visitor.reduceUndefined(*this);
+  template <class V>
+  typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
+    return Vs.reduceUndefined(*this);
   }
 
   template <class C> typename C::CType compare(Undefined* E, C& Cmp) {
@@ -589,8 +586,8 @@ public:
   Wildcard() : SExpr(COP_Wildcard) {}
   Wildcard(const Wildcard &W) : SExpr(W) {}
 
-  template <class V> typename V::R_SExpr traverse(V &Visitor) {
-    return Visitor.reduceWildcard(*this);
+  template <class V> typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
+    return Vs.reduceWildcard(*this);
   }
 
   template <class C> typename C::CType compare(Wildcard* E, C& Cmp) {
@@ -615,16 +612,14 @@ public:
 
   ValueType valueType() const { return ValType; }
 
-  template <class V> typename V::R_SExpr traverse(V &Visitor) {
-    return Visitor.reduceLiteral(*this);
-  }
+  template <class V> typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx);
 
   template <class C> typename C::CType compare(Literal* E, C& Cmp) {
     // TODO -- use value, not pointer equality
     return Cmp.comparePointers(Cexpr, E->Cexpr);
   }
 
-private:
+protected:
   const ValueType ValType;
   const clang::Expr *Cexpr;
 };
@@ -645,6 +640,63 @@ private:
 };
 
 
+template <class V>
+typename V::R_SExpr Literal::traverse(V &Vs, typename V::R_Ctx Ctx) {
+  if (Cexpr)
+    return Vs.reduceLiteral(*this);
+
+  switch (ValType.Base) {
+  case ValueType::BT_Void:
+    break;
+  case ValueType::BT_Bool:
+    return Vs.reduceLiteralT(*static_cast<LiteralT<bool>*>(this));
+  case ValueType::BT_Int: {
+    switch (ValType.Size) {
+    case ValueType::ST_8:
+      if (ValType.Signed)
+        return Vs.reduceLiteralT(*static_cast<LiteralT<int8_t>*>(this));
+      else
+        return Vs.reduceLiteralT(*static_cast<LiteralT<uint8_t>*>(this));
+    case ValueType::ST_16:
+      if (ValType.Signed)
+        return Vs.reduceLiteralT(*static_cast<LiteralT<int16_t>*>(this));
+      else
+        return Vs.reduceLiteralT(*static_cast<LiteralT<uint16_t>*>(this));
+    case ValueType::ST_32:
+      if (ValType.Signed)
+        return Vs.reduceLiteralT(*static_cast<LiteralT<int32_t>*>(this));
+      else
+        return Vs.reduceLiteralT(*static_cast<LiteralT<uint32_t>*>(this));
+    case ValueType::ST_64:
+      if (ValType.Signed)
+        return Vs.reduceLiteralT(*static_cast<LiteralT<int64_t>*>(this));
+      else
+        return Vs.reduceLiteralT(*static_cast<LiteralT<uint64_t>*>(this));
+    default:
+      break;
+    }
+  }
+  case ValueType::BT_Float: {
+    switch (ValType.Size) {
+    case ValueType::ST_32:
+      return Vs.reduceLiteralT(*static_cast<LiteralT<float>*>(this));
+    case ValueType::ST_64:
+      return Vs.reduceLiteralT(*static_cast<LiteralT<double>*>(this));
+    default:
+      break;
+    }
+  }
+  case ValueType::BT_String:
+    return Vs.reduceLiteralT(*static_cast<LiteralT<StringRef>*>(this));
+  case ValueType::BT_Pointer:
+    return Vs.reduceLiteralT(*static_cast<LiteralT<void*>*>(this));
+  case ValueType::BT_ValueRef:
+    break;
+  }
+  return Vs.reduceLiteral(*this);
+}
+
+
 // Literal pointer to an object allocated in memory.
 // At compile time, pointer literals are represented by symbolic names.
 class LiteralPtr : public SExpr {
@@ -657,8 +709,9 @@ public:
   // The clang declaration for the value that this pointer points to.
   const clang::ValueDecl *clangDecl() const { return Cvdecl; }
 
-  template <class V> typename V::R_SExpr traverse(V &Visitor) {
-    return Visitor.reduceLiteralPtr(*this);
+  template <class V>
+  typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
+    return Vs.reduceLiteralPtr(*this);
   }
 
   template <class C> typename C::CType compare(LiteralPtr* E, C& Cmp) {
@@ -692,14 +745,15 @@ public:
   SExpr *body() { return Body.get(); }
   const SExpr *body() const { return Body.get(); }
 
-  template <class V> typename V::R_SExpr traverse(V &Visitor) {
+  template <class V>
+  typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
     // This is a variable declaration, so traverse the definition.
-    typename V::R_SExpr E0 = Visitor.traverse(VarDecl->Definition, TRV_Lazy);
+    auto E0 = Vs.traverse(VarDecl->Definition, Vs.typeCtx(Ctx));
     // Tell the rewriter to enter the scope of the function.
-    Variable *Nvd = Visitor.enterScope(*VarDecl, E0);
-    typename V::R_SExpr E1 = Visitor.traverse(Body);
-    Visitor.exitScope(*VarDecl);
-    return Visitor.reduceFunction(*this, Nvd, E1);
+    Variable *Nvd = Vs.enterScope(*VarDecl, E0);
+    auto E1 = Vs.traverse(Body, Vs.declCtx(Ctx));
+    Vs.exitScope(*VarDecl);
+    return Vs.reduceFunction(*this, Nvd, E1);
   }
 
   template <class C> typename C::CType compare(Function* E, C& Cmp) {
@@ -745,15 +799,16 @@ public:
   SExpr *body() { return Body.get(); }
   const SExpr *body() const { return Body.get(); }
 
-  template <class V> typename V::R_SExpr traverse(V &Visitor) {
+  template <class V>
+  typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
     // A self-variable points to the SFunction itself.
     // A rewrite must introduce the variable with a null definition, and update
     // it after 'this' has been rewritten.
-    Variable *Nvd = Visitor.enterScope(*VarDecl, nullptr /* def */);
-    typename V::R_SExpr E1 = Visitor.traverse(Body);
-    Visitor.exitScope(*VarDecl);
+    Variable *Nvd = Vs.enterScope(*VarDecl, nullptr);
+    auto E1 = Vs.traverse(Body, Vs.declCtx(Ctx));
+    Vs.exitScope(*VarDecl);
     // A rewrite operation will call SFun constructor to set Vvd->Definition.
-    return Visitor.reduceSFunction(*this, Nvd, E1);
+    return Vs.reduceSFunction(*this, Nvd, E1);
   }
 
   template <class C> typename C::CType compare(SFunction* E, C& Cmp) {
@@ -784,10 +839,11 @@ public:
   SExpr *body() { return Body.get(); }
   const SExpr *body() const { return Body.get(); }
 
-  template <class V> typename V::R_SExpr traverse(V &Visitor) {
-    typename V::R_SExpr Nt = Visitor.traverse(ReturnType, TRV_Lazy);
-    typename V::R_SExpr Nb = Visitor.traverse(Body, TRV_Lazy);
-    return Visitor.reduceCode(*this, Nt, Nb);
+  template <class V>
+  typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
+    auto Nt = Vs.traverse(ReturnType, Vs.typeCtx(Ctx));
+    auto Nb = Vs.traverse(Body,       Vs.lazyCtx(Ctx));
+    return Vs.reduceCode(*this, Nt, Nb);
   }
 
   template <class C> typename C::CType compare(Code* E, C& Cmp) {
@@ -818,10 +874,11 @@ public:
   SExpr *body() { return Body.get(); }
   const SExpr *body() const { return Body.get(); }
 
-  template <class V> typename V::R_SExpr traverse(V &Visitor) {
-    typename V::R_SExpr Nr = Visitor.traverse(Range, TRV_Lazy);
-    typename V::R_SExpr Nb = Visitor.traverse(Body,  TRV_Lazy);
-    return Visitor.reduceField(*this, Nr, Nb);
+  template <class V>
+  typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
+    auto Nr = Vs.traverse(Range, Vs.typeCtx(Ctx));
+    auto Nb = Vs.traverse(Body,  Vs.lazyCtx(Ctx));
+    return Vs.reduceField(*this, Nr, Nb);
   }
 
   template <class C> typename C::CType compare(Field* E, C& Cmp) {
@@ -853,10 +910,11 @@ public:
   SExpr *arg() { return Arg.get(); }
   const SExpr *arg() const { return Arg.get(); }
 
-  template <class V> typename V::R_SExpr traverse(V &Visitor) {
-    typename V::R_SExpr Nf = Visitor.traverse(Fun);
-    typename V::R_SExpr Na = Visitor.traverse(Arg);
-    return Visitor.reduceApply(*this, Nf, Na);
+  template <class V>
+  typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
+    auto Nf = Vs.traverse(Fun, Vs.subExprCtx(Ctx));
+    auto Na = Vs.traverse(Arg, Vs.subExprCtx(Ctx));
+    return Vs.reduceApply(*this, Nf, Na);
   }
 
   template <class C> typename C::CType compare(Apply* E, C& Cmp) {
@@ -889,10 +947,12 @@ public:
 
   bool isDelegation() const { return Arg == nullptr; }
 
-  template <class V> typename V::R_SExpr traverse(V &Visitor) {
-    typename V::R_SExpr Nf = Visitor.traverse(Sfun);
-    typename V::R_SExpr Na = Arg.get() ? Visitor.traverse(Arg) : nullptr;
-    return Visitor.reduceSApply(*this, Nf, Na);
+  template <class V>
+  typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
+    auto Nf = Vs.traverse(Sfun, Vs.subExprCtx(Ctx));
+    typename V::R_SExpr Na = Arg.get() ? Vs.traverse(Arg, Vs.subExprCtx(Ctx))
+                                       : nullptr;
+    return Vs.reduceSApply(*this, Nf, Na);
   }
 
   template <class C> typename C::CType compare(SApply* E, C& Cmp) {
@@ -935,9 +995,10 @@ public:
       return SlotName;
   }
 
-  template <class V> typename V::R_SExpr traverse(V &Visitor) {
-    typename V::R_SExpr Nr = Visitor.traverse(Rec);
-    return Visitor.reduceProject(*this, Nr);
+  template <class V>
+  typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
+    auto Nr = Vs.traverse(Rec, Vs.subExprCtx(Ctx));
+    return Vs.reduceProject(*this, Nr);
   }
 
   template <class C> typename C::CType compare(Project* E, C& Cmp) {
@@ -968,9 +1029,10 @@ public:
 
   const clang::CallExpr *clangCallExpr() const { return Cexpr; }
 
-  template <class V> typename V::R_SExpr traverse(V &Visitor) {
-    typename V::R_SExpr Nt = Visitor.traverse(Target);
-    return Visitor.reduceCall(*this, Nt);
+  template <class V>
+  typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
+    auto Nt = Vs.traverse(Target, Vs.subExprCtx(Ctx));
+    return Vs.reduceCall(*this, Nt);
   }
 
   template <class C> typename C::CType compare(Call* E, C& Cmp) {
@@ -1001,9 +1063,10 @@ public:
   SExpr *dataType() { return Dtype.get(); }
   const SExpr *dataType() const { return Dtype.get(); }
 
-  template <class V> typename V::R_SExpr traverse(V &Visitor) {
-    typename V::R_SExpr Nd = Visitor.traverse(Dtype);
-    return Visitor.reduceAlloc(*this, Nd);
+  template <class V>
+  typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
+    auto Nd = Vs.traverse(Dtype, Vs.declCtx(Ctx));
+    return Vs.reduceAlloc(*this, Nd);
   }
 
   template <class C> typename C::CType compare(Alloc* E, C& Cmp) {
@@ -1029,9 +1092,10 @@ public:
   SExpr *pointer() { return Ptr.get(); }
   const SExpr *pointer() const { return Ptr.get(); }
 
-  template <class V> typename V::R_SExpr traverse(V &Visitor) {
-    typename V::R_SExpr Np = Visitor.traverse(Ptr);
-    return Visitor.reduceLoad(*this, Np);
+  template <class V>
+  typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
+    auto Np = Vs.traverse(Ptr, Vs.subExprCtx(Ctx));
+    return Vs.reduceLoad(*this, Np);
   }
 
   template <class C> typename C::CType compare(Load* E, C& Cmp) {
@@ -1058,10 +1122,11 @@ public:
   SExpr *source() { return Source.get(); }     // Value to store
   const SExpr *source() const { return Source.get(); }
 
-  template <class V> typename V::R_SExpr traverse(V &Visitor) {
-    typename V::R_SExpr Np = Visitor.traverse(Dest);
-    typename V::R_SExpr Nv = Visitor.traverse(Source);
-    return Visitor.reduceStore(*this, Np, Nv);
+  template <class V>
+  typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
+    auto Np = Vs.traverse(Dest,   Vs.subExprCtx(Ctx));
+    auto Nv = Vs.traverse(Source, Vs.subExprCtx(Ctx));
+    return Vs.reduceStore(*this, Np, Nv);
   }
 
   template <class C> typename C::CType compare(Store* E, C& Cmp) {
@@ -1079,27 +1144,37 @@ private:
 
 // If p is a reference to an array, then first(p) is a reference to the first
 // element.  The usual array notation p[i]  becomes first(p + i).
-class ArrayFirst : public SExpr {
+class ArrayIndex : public SExpr {
 public:
-  static bool classof(const SExpr *E) { return E->opcode() == COP_ArrayFirst; }
+  static bool classof(const SExpr *E) { return E->opcode() == COP_ArrayIndex; }
 
-  ArrayFirst(SExpr *A) : SExpr(COP_ArrayFirst), Array(A) {}
-  ArrayFirst(const ArrayFirst &E, SExpr *A) : SExpr(E), Array(A) {}
+  ArrayIndex(SExpr *A, SExpr *N) : SExpr(COP_ArrayIndex), Array(A), Index(N) {}
+  ArrayIndex(const ArrayIndex &E, SExpr *A, SExpr *N)
+    : SExpr(E), Array(A), Index(N) {}
 
   SExpr *array() { return Array.get(); }
   const SExpr *array() const { return Array.get(); }
 
-  template <class V> typename V::R_SExpr traverse(V &Visitor) {
-    typename V::R_SExpr Na = Visitor.traverse(Array);
-    return Visitor.reduceArrayFirst(*this, Na);
+  SExpr *index() { return Index.get(); }
+  const SExpr *index() const { return Index.get(); }
+
+  template <class V>
+  typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
+    auto Na = Vs.traverse(Array, Vs.subExprCtx(Ctx));
+    auto Ni = Vs.traverse(Index, Vs.subExprCtx(Ctx));
+    return Vs.reduceArrayIndex(*this, Na, Ni);
   }
 
-  template <class C> typename C::CType compare(ArrayFirst* E, C& Cmp) {
-    return Cmp.compare(array(), E->array());
+  template <class C> typename C::CType compare(ArrayIndex* E, C& Cmp) {
+    typename C::CType Ct = Cmp.compare(array(), E->array());
+    if (Cmp.notTrue(Ct))
+      return Ct;
+    return Cmp.compare(index(), E->index());
   }
 
 private:
   SExprRef Array;
+  SExprRef Index;
 };
 
 
@@ -1120,10 +1195,11 @@ public:
   SExpr *index() { return Index.get(); }
   const SExpr *index() const { return Index.get(); }
 
-  template <class V> typename V::R_SExpr traverse(V &Visitor) {
-    typename V::R_SExpr Na = Visitor.traverse(Array);
-    typename V::R_SExpr Ni = Visitor.traverse(Index);
-    return Visitor.reduceArrayAdd(*this, Na, Ni);
+  template <class V>
+  typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
+    auto Na = Vs.traverse(Array, Vs.subExprCtx(Ctx));
+    auto Ni = Vs.traverse(Index, Vs.subExprCtx(Ctx));
+    return Vs.reduceArrayAdd(*this, Na, Ni);
   }
 
   template <class C> typename C::CType compare(ArrayAdd* E, C& Cmp) {
@@ -1156,9 +1232,10 @@ public:
   SExpr *expr() { return Expr0.get(); }
   const SExpr *expr() const { return Expr0.get(); }
 
-  template <class V> typename V::R_SExpr traverse(V &Visitor) {
-    typename V::R_SExpr Ne = Visitor.traverse(Expr0);
-    return Visitor.reduceUnaryOp(*this, Ne);
+  template <class V>
+  typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
+    auto Ne = Vs.traverse(Expr0, Vs.subExprCtx(Ctx));
+    return Vs.reduceUnaryOp(*this, Ne);
   }
 
   template <class C> typename C::CType compare(UnaryOp* E, C& Cmp) {
@@ -1198,10 +1275,11 @@ public:
   SExpr *expr1() { return Expr1.get(); }
   const SExpr *expr1() const { return Expr1.get(); }
 
-  template <class V> typename V::R_SExpr traverse(V &Visitor) {
-    typename V::R_SExpr Ne0 = Visitor.traverse(Expr0);
-    typename V::R_SExpr Ne1 = Visitor.traverse(Expr1);
-    return Visitor.reduceBinaryOp(*this, Ne0, Ne1);
+  template <class V>
+  typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
+    auto Ne0 = Vs.traverse(Expr0, Vs.subExprCtx(Ctx));
+    auto Ne1 = Vs.traverse(Expr1, Vs.subExprCtx(Ctx));
+    return Vs.reduceBinaryOp(*this, Ne0, Ne1);
   }
 
   template <class C> typename C::CType compare(BinaryOp* E, C& Cmp) {
@@ -1236,9 +1314,10 @@ public:
   SExpr *expr() { return Expr0.get(); }
   const SExpr *expr() const { return Expr0.get(); }
 
-  template <class V> typename V::R_SExpr traverse(V &Visitor) {
-    typename V::R_SExpr Ne = Visitor.traverse(Expr0);
-    return Visitor.reduceCast(*this, Ne);
+  template <class V>
+  typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
+    auto Ne = Vs.traverse(Expr0, Vs.subExprCtx(Ctx));
+    return Vs.reduceCast(*this, Ne);
   }
 
   template <class C> typename C::CType compare(Cast* E, C& Cmp) {
@@ -1254,57 +1333,53 @@ private:
 };
 
 
+class SCFG;
 
-class BasicBlock;
 
-// An SCFG is a control-flow graph.  It consists of a set of basic blocks, each
-// of which terminates in a branch to another basic block.  There is one
-// entry point, and one exit point.
-class SCFG : public SExpr {
+class Phi : public SExpr {
 public:
-  typedef SimpleArray<BasicBlock *> BlockArray;
-  typedef BlockArray::iterator iterator;
-  typedef BlockArray::const_iterator const_iterator;
-
-  static bool classof(const SExpr *E) { return E->opcode() == COP_SCFG; }
+  // TODO: change to SExprRef
+  typedef SimpleArray<SExpr *> ValArray;
 
-  SCFG(MemRegionRef A, unsigned Nblocks)
-      : SExpr(COP_SCFG), Blocks(A, Nblocks),
-        Entry(nullptr), Exit(nullptr) {}
-  SCFG(const SCFG &Cfg, BlockArray &&Ba) // steals memory from Ba
-      : SExpr(COP_SCFG), Blocks(std::move(Ba)), Entry(nullptr), Exit(nullptr) {
-    // TODO: set entry and exit!
-  }
+  // In minimal SSA form, all Phi nodes are MultiVal.
+  // During conversion to SSA, incomplete Phi nodes may be introduced, which
+  // are later determined to be SingleVal, and are thus redundant.
+  enum Status {
+    PH_MultiVal = 0, // Phi node has multiple distinct values.  (Normal)
+    PH_SingleVal,    // Phi node has one distinct value, and can be eliminated
+    PH_Incomplete    // Phi node is incomplete
+  };
 
-  iterator begin() { return Blocks.begin(); }
-  iterator end() { return Blocks.end(); }
+  static bool classof(const SExpr *E) { return E->opcode() == COP_Phi; }
 
-  const_iterator begin() const { return cbegin(); }
-  const_iterator end() const { return cend(); }
+  Phi() : SExpr(COP_Phi) {}
+  Phi(MemRegionRef A, unsigned Nvals) : SExpr(COP_Phi), Values(A, Nvals) {}
+  Phi(const Phi &P, ValArray &&Vs)    : SExpr(P), Values(std::move(Vs)) {}
 
-  const_iterator cbegin() const { return Blocks.cbegin(); }
-  const_iterator cend() const { return Blocks.cend(); }
+  const ValArray &values() const { return Values; }
+  ValArray &values() { return Values; }
 
-  const BasicBlock *entry() const { return Entry; }
-  BasicBlock *entry() { return Entry; }
-  const BasicBlock *exit() const { return Exit; }
-  BasicBlock *exit() { return Exit; }
+  Status status() const { return static_cast<Status>(Flags); }
+  void setStatus(Status s) { Flags = s; }
 
-  void add(BasicBlock *BB);
-  void setEntry(BasicBlock *BB) { Entry = BB; }
-  void setExit(BasicBlock *BB) { Exit = BB; }
+  template <class V>
+  typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
+    typename V::template Container<typename V::R_SExpr>
+      Nvs(Vs, Values.size());
 
-  template <class V> typename V::R_SExpr traverse(V &Visitor);
+    for (auto *Val : Values) {
+      Nvs.push_back( Vs.traverse(Val, Vs.subExprCtx(Ctx)) );
+    }
+    return Vs.reducePhi(*this, Nvs);
+  }
 
-  template <class C> typename C::CType compare(SCFG *E, C &Cmp) {
-    // TODO -- implement CFG comparisons
+  template <class C> typename C::CType compare(Phi *E, C &Cmp) {
+    // TODO: implement CFG comparisons
     return Cmp.comparePointers(this, E);
   }
 
 private:
-  BlockArray Blocks;
-  BasicBlock *Entry;
-  BasicBlock *Exit;
+  ValArray Values;
 };
 
 
@@ -1313,21 +1388,28 @@ private:
 // are "arguments" to the function, followed by a sequence of instructions.
 // Both arguments and instructions define new variables.  It ends with a
 // branch or goto to another basic block in the same SCFG.
-class BasicBlock {
+class BasicBlock : public SExpr {
 public:
-  typedef SimpleArray<Variable*> VarArray;
+  typedef SimpleArray<Variable*>   VarArray;
+  typedef SimpleArray<BasicBlock*> BlockArray;
+
+  static bool classof(const SExpr *E) { return E->opcode() == COP_BasicBlock; }
 
-  BasicBlock(MemRegionRef A, unsigned Nargs, unsigned Nins,
-             SExpr *Term = nullptr)
-      : BlockID(0), NumVars(0), NumPredecessors(0), Parent(nullptr),
-        Args(A, Nargs), Instrs(A, Nins), Terminator(Term) {}
-  BasicBlock(const BasicBlock &B, VarArray &&As, VarArray &&Is, SExpr *T)
-      : BlockID(0),  NumVars(B.NumVars), NumPredecessors(B.NumPredecessors),
+  explicit BasicBlock(MemRegionRef A, BasicBlock* P = nullptr)
+      : SExpr(COP_BasicBlock), Arena(A), CFGPtr(nullptr), BlockID(0),
+        Parent(P), Terminator(nullptr)
+  { }
+  BasicBlock(BasicBlock &B, VarArray &&As, VarArray &&Is, SExpr *T)
+      : SExpr(COP_BasicBlock), Arena(B.Arena), CFGPtr(nullptr), BlockID(0),
         Parent(nullptr), Args(std::move(As)), Instrs(std::move(Is)),
-        Terminator(T) {}
+        Terminator(T)
+  { }
 
   unsigned blockID() const { return BlockID; }
-  unsigned numPredecessors() const { return NumPredecessors; }
+  unsigned numPredecessors() const { return Predecessors.size(); }
+
+  const SCFG* cfg() const { return CFGPtr; }
+  SCFG* cfg() { return CFGPtr; }
 
   const BasicBlock *parent() const { return Parent; }
   BasicBlock *parent() { return Parent; }
@@ -1338,46 +1420,76 @@ public:
   const VarArray &instructions() const { return Instrs; }
   VarArray &instructions() { return Instrs; }
 
+  const BlockArray &predecessors() const { return Predecessors; }
+  BlockArray &predecessors() { return Predecessors; }
+
   const SExpr *terminator() const { return Terminator.get(); }
   SExpr *terminator() { return Terminator.get(); }
 
-  void setBlockID(unsigned i) { BlockID = i; }
-  void setParent(BasicBlock *P) { Parent = P; }
-  void setNumPredecessors(unsigned NP) { NumPredecessors = NP; }
-  void setTerminator(SExpr *E) { Terminator.reset(E); }
+  void setBlockID(unsigned i)   { BlockID = i; }
+  void setParent(BasicBlock *P) { Parent = P;  }
+  void setTerminator(SExpr *E)  { Terminator.reset(E); }
 
+  // Add a new argument.  V must define a phi-node.
   void addArgument(Variable *V) {
-    V->setID(BlockID, NumVars++);
+    Args.reserveCheck(1, Arena);
     Args.push_back(V);
   }
+  // Add a new instruction.
   void addInstruction(Variable *V) {
-    V->setID(BlockID, NumVars++);
+    Instrs.reserveCheck(1, Arena);
     Instrs.push_back(V);
   }
+  // Add a new predecessor, and return the phi-node index for it.
+  // Will add an argument to all phi-nodes, initialized to nullptr.
+  unsigned addPredecessor(BasicBlock *Pred);
+
+  // Reserve space for Nargs arguments.
+  void reserveArguments(unsigned Nargs)   { Args.reserve(Nargs, Arena); }
+
+  // Reserve space for Nins instructions.
+  void reserveInstructions(unsigned Nins) { Instrs.reserve(Nins, Arena); }
+
+  // Reserve space for NumPreds predecessors, including space in phi nodes.
+  void reservePredecessors(unsigned NumPreds);
+
+  // Return the index of BB, or Predecessors.size if BB is not a predecessor.
+  unsigned findPredecessorIndex(BasicBlock *BB) {
+    unsigned I = 0;
+    for (BasicBlock *B : Predecessors) {
+      if (B == BB) return I;
+      ++I;
+    }
+    return Predecessors.size();
+  }
 
-  template <class V> BasicBlock *traverse(V &Visitor) {
-    typename V::template Container<Variable*> Nas(Visitor, Args.size());
-    typename V::template Container<Variable*> Nis(Visitor, Instrs.size());
+  // Set id numbers for variables.
+  void renumberVars();
+
+  template <class V>
+  typename V::R_BasicBlock traverse(V &Vs, typename V::R_Ctx Ctx) {
+    typename V::template Container<Variable*> Nas(Vs, Args.size());
+    typename V::template Container<Variable*> Nis(Vs, Instrs.size());
+
+    // Entering the basic block should do any scope initialization.
+    Vs.enterBasicBlock(*this);
 
     for (auto *A : Args) {
-      typename V::R_SExpr Ne = Visitor.traverse(A->Definition);
-      Variable *Nvd = Visitor.enterScope(*A, Ne);
+      auto Ne = Vs.traverse(A->Definition, Vs.subExprCtx(Ctx));
+      Variable *Nvd = Vs.enterScope(*A, Ne);
       Nas.push_back(Nvd);
     }
     for (auto *I : Instrs) {
-      typename V::R_SExpr Ne = Visitor.traverse(I->Definition);
-      Variable *Nvd = Visitor.enterScope(*I, Ne);
+      auto Ne = Vs.traverse(I->Definition, Vs.subExprCtx(Ctx));
+      Variable *Nvd = Vs.enterScope(*I, Ne);
       Nis.push_back(Nvd);
     }
-    typename V::R_SExpr Nt = Visitor.traverse(Terminator);
+    auto Nt = Vs.traverse(Terminator, Ctx);
 
-    // TODO: use reverse iterator
-    for (unsigned J = 0, JN = Instrs.size(); J < JN; ++J)
-      Visitor.exitScope(*Instrs[JN-J]);
-    for (unsigned I = 0, IN = Instrs.size(); I < IN; ++I)
-      Visitor.exitScope(*Args[IN-I]);
+    // Exiting the basic block should handle any scope cleanup.
+    Vs.exitBasicBlock(*this);
 
-    return Visitor.reduceBasicBlock(*this, Nas, Nis, Nt);
+    return Vs.reduceBasicBlock(*this, Nas, Nis, Nt);
   }
 
   template <class C> typename C::CType compare(BasicBlock *E, C &Cmp) {
@@ -1388,80 +1500,95 @@ public:
 private:
   friend class SCFG;
 
-  unsigned BlockID;
-  unsigned NumVars;
-  unsigned NumPredecessors; // Number of blocks which jump to this one.
+  MemRegionRef Arena;
 
+  SCFG       *CFGPtr;       // The CFG that contains this block.
+  unsigned   BlockID;       // unique id for this BB in the containing CFG
   BasicBlock *Parent;       // The parent block is the enclosing lexical scope.
                             // The parent dominates this block.
-  VarArray Args;            // Phi nodes.  One argument per predecessor.
-  VarArray Instrs;
-  SExprRef Terminator;
+  BlockArray Predecessors;  // Predecessor blocks in the CFG.
+  VarArray   Args;          // Phi nodes.  One argument per predecessor.
+  VarArray   Instrs;        // Instructions.
+  SExprRef   Terminator;    // Branch or Goto
 };
 
 
-inline void SCFG::add(BasicBlock *BB) {
-  BB->setBlockID(Blocks.size());
-  Blocks.push_back(BB);
-}
+// An SCFG is a control-flow graph.  It consists of a set of basic blocks, each
+// of which terminates in a branch to another basic block.  There is one
+// entry point, and one exit point.
+class SCFG : public SExpr {
+public:
+  typedef SimpleArray<BasicBlock *> BlockArray;
+  typedef BlockArray::iterator iterator;
+  typedef BlockArray::const_iterator const_iterator;
 
+  static bool classof(const SExpr *E) { return E->opcode() == COP_SCFG; }
 
-template <class V>
-typename V::R_SExpr SCFG::traverse(V &Visitor) {
-  Visitor.enterCFG(*this);
-  typename V::template Container<BasicBlock *> Bbs(Visitor, Blocks.size());
-  for (auto *B : Blocks) {
-    BasicBlock *Nbb = B->traverse(Visitor);
-    Bbs.push_back(Nbb);
+  SCFG(MemRegionRef A, unsigned Nblocks)
+    : SExpr(COP_SCFG), Arena(A), Blocks(A, Nblocks),
+      Entry(nullptr), Exit(nullptr) {
+    Entry = new (A) BasicBlock(A, nullptr);
+    Exit  = new (A) BasicBlock(A, Entry);
+    auto *V = new (A) Variable(new (A) Phi());
+    Exit->addArgument(V);
+    add(Entry);
+    add(Exit);
+  }
+  SCFG(const SCFG &Cfg, BlockArray &&Ba) // steals memory from Ba
+      : SExpr(COP_SCFG), Arena(Cfg.Arena), Blocks(std::move(Ba)),
+        Entry(nullptr), Exit(nullptr) {
+    // TODO: set entry and exit!
   }
-  Visitor.exitCFG(*this);
-  return Visitor.reduceSCFG(*this, Bbs);
-}
 
+  iterator begin() { return Blocks.begin(); }
+  iterator end() { return Blocks.end(); }
 
-class Phi : public SExpr {
-public:
-  // TODO: change to SExprRef
-  typedef SimpleArray<SExpr *> ValArray;
+  const_iterator begin() const { return cbegin(); }
+  const_iterator end() const { return cend(); }
 
-  // In minimal SSA form, all Phi nodes are MultiVal.
-  // During conversion to SSA, incomplete Phi nodes may be introduced, which
-  // are later determined to be SingleVal.
-  enum Status {
-    PH_MultiVal = 0, // Phi node has multiple distinct values.  (Normal)
-    PH_SingleVal,    // Phi node has one distinct value, and can be eliminated
-    PH_Incomplete    // Phi node is incomplete
-  };
+  const_iterator cbegin() const { return Blocks.cbegin(); }
+  const_iterator cend() const { return Blocks.cend(); }
 
-  static bool classof(const SExpr *E) { return E->opcode() == COP_Phi; }
+  const BasicBlock *entry() const { return Entry; }
+  BasicBlock *entry() { return Entry; }
+  const BasicBlock *exit() const { return Exit; }
+  BasicBlock *exit() { return Exit; }
 
-  Phi(MemRegionRef A, unsigned Nvals) : SExpr(COP_Phi), Values(A, Nvals) {}
-  Phi(const Phi &P, ValArray &&Vs) // steals memory of Vs
-      : SExpr(COP_Phi), Values(std::move(Vs)) {}
+  inline void add(BasicBlock *BB) {
+    assert(BB->CFGPtr == nullptr || BB->CFGPtr == this);
+    BB->setBlockID(Blocks.size());
+    BB->CFGPtr = this;
+    Blocks.reserveCheck(1, Arena);
+    Blocks.push_back(BB);
+  }
 
-  const ValArray &values() const { return Values; }
-  ValArray &values() { return Values; }
+  void setEntry(BasicBlock *BB) { Entry = BB; }
+  void setExit(BasicBlock *BB)  { Exit = BB;  }
 
-  Status status() const { return static_cast<Status>(Flags); }
-  void setStatus(Status s) { Flags = s; }
+  // Set varable ids in all blocks.
+  void renumberVars();
 
-  template <class V> typename V::R_SExpr traverse(V &Visitor) {
-    typename V::template Container<typename V::R_SExpr> Nvs(Visitor,
-                                                            Values.size());
-    for (auto *Val : Values) {
-      typename V::R_SExpr Nv = Visitor.traverse(Val);
-      Nvs.push_back(Nv);
+  template <class V>
+  typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
+    Vs.enterCFG(*this);
+    typename V::template Container<BasicBlock *> Bbs(Vs, Blocks.size());
+    for (auto *B : Blocks) {
+      Bbs.push_back( B->traverse(Vs, Vs.subExprCtx(Ctx)) );
     }
-    return Visitor.reducePhi(*this, Nvs);
+    Vs.exitCFG(*this);
+    return Vs.reduceSCFG(*this, Bbs);
   }
 
-  template <class C> typename C::CType compare(Phi *E, C &Cmp) {
-    // TODO: implement CFG comparisons
+  template <class C> typename C::CType compare(SCFG *E, C &Cmp) {
+    // TODO -- implement CFG comparisons
     return Cmp.comparePointers(this, E);
   }
 
 private:
-  ValArray Values;
+  MemRegionRef Arena;
+  BlockArray   Blocks;
+  BasicBlock   *Entry;
+  BasicBlock   *Exit;
 };
 
 
@@ -1469,8 +1596,8 @@ class Goto : public SExpr {
 public:
   static bool classof(const SExpr *E) { return E->opcode() == COP_Goto; }
 
-  Goto(BasicBlock *B, unsigned Index)
-      : SExpr(COP_Goto), TargetBlock(B), Index(0) {}
+  Goto(BasicBlock *B, unsigned I)
+      : SExpr(COP_Goto), TargetBlock(B), Index(I) {}
   Goto(const Goto &G, BasicBlock *B, unsigned I)
       : SExpr(COP_Goto), TargetBlock(B), Index(I) {}
 
@@ -1479,10 +1606,10 @@ public:
 
   unsigned index() const { return Index; }
 
-  template <class V> typename V::R_SExpr traverse(V &Visitor) {
-    // TODO -- rewrite indices properly
-    BasicBlock *Ntb = Visitor.reduceBasicBlockRef(TargetBlock);
-    return Visitor.reduceGoto(*this, Ntb, Index);
+  template <class V>
+  typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
+    BasicBlock *Ntb = Vs.reduceBasicBlockRef(TargetBlock);
+    return Vs.reduceGoto(*this, Ntb);
   }
 
   template <class C> typename C::CType compare(Goto *E, C &Cmp) {
@@ -1500,13 +1627,14 @@ class Branch : public SExpr {
 public:
   static bool classof(const SExpr *E) { return E->opcode() == COP_Branch; }
 
-  Branch(SExpr *C, BasicBlock *T, BasicBlock *E)
+  Branch(SExpr *C, BasicBlock *T, BasicBlock *E, unsigned TI, unsigned EI)
       : SExpr(COP_Branch), Condition(C), ThenBlock(T), ElseBlock(E),
-        ThenIndex(0), ElseIndex(0)
+        ThenIndex(TI), ElseIndex(EI)
   {}
-  Branch(const Branch &Br, SExpr *C, BasicBlock *T, BasicBlock *E)
+  Branch(const Branch &Br, SExpr *C, BasicBlock *T, BasicBlock *E,
+         unsigned TI, unsigned EI)
       : SExpr(COP_Branch), Condition(C), ThenBlock(T), ElseBlock(E),
-        ThenIndex(0), ElseIndex(0)
+        ThenIndex(TI), ElseIndex(EI)
   {}
 
   const SExpr *condition() const { return Condition; }
@@ -1521,11 +1649,12 @@ public:
   unsigned thenIndex() const { return ThenIndex; }
   unsigned elseIndex() const { return ElseIndex; }
 
-  template <class V> typename V::R_SExpr traverse(V &Visitor) {
-    typename V::R_SExpr Nc = Visitor.traverse(Condition);
-    BasicBlock *Ntb = Visitor.reduceBasicBlockRef(ThenBlock);
-    BasicBlock *Nte = Visitor.reduceBasicBlockRef(ElseBlock);
-    return Visitor.reduceBranch(*this, Nc, Ntb, Nte);
+  template <class V>
+  typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
+    auto Nc = Vs.traverse(Condition, Vs.subExprCtx(Ctx));
+    BasicBlock *Ntb = Vs.reduceBasicBlockRef(ThenBlock);
+    BasicBlock *Nte = Vs.reduceBasicBlockRef(ElseBlock);
+    return Vs.reduceBranch(*this, Nc, Ntb, Nte);
   }
 
   template <class C> typename C::CType compare(Branch *E, C &Cmp) {
@@ -1553,8 +1682,9 @@ public:
 
   StringRef name() const { return Name; }
 
-  template <class V> typename V::R_SExpr traverse(V &Visitor) {
-    return Visitor.reduceIdentifier(*this);
+  template <class V>
+  typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
+    return Vs.reduceIdentifier(*this);
   }
 
   template <class C> typename C::CType compare(Identifier* E, C& Cmp) {
@@ -1567,7 +1697,7 @@ private:
 
 
 // An if-then-else expression.
-// This is a pseduo-term; it will be lowered to a CFG.
+// This is a pseduo-term; it will be lowered to a branch in a CFG.
 class IfThenElse : public SExpr {
 public:
   static bool classof(const SExpr *E) { return E->opcode() == COP_IfThenElse; }
@@ -1588,11 +1718,12 @@ public:
   SExpr *elseExpr() { return ElseExpr.get(); }     // Value to store
   const SExpr *elseExpr() const { return ElseExpr.get(); }
 
-  template <class V> typename V::R_SExpr traverse(V &Visitor) {
-    typename V::R_SExpr Nc = Visitor.traverse(Condition);
-    typename V::R_SExpr Nt = Visitor.traverse(ThenExpr);
-    typename V::R_SExpr Ne = Visitor.traverse(ElseExpr);
-    return Visitor.reduceIfThenElse(*this, Nc, Nt, Ne);
+  template <class V>
+  typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
+    auto Nc = Vs.traverse(Condition, Vs.subExprCtx(Ctx));
+    auto Nt = Vs.traverse(ThenExpr,  Vs.subExprCtx(Ctx));
+    auto Ne = Vs.traverse(ElseExpr,  Vs.subExprCtx(Ctx));
+    return Vs.reduceIfThenElse(*this, Nc, Nt, Ne);
   }
 
   template <class C> typename C::CType compare(IfThenElse* E, C& Cmp) {
@@ -1613,7 +1744,7 @@ private:
 
 
 // A let-expression,  e.g.  let x=t; u.
-// This is a pseduo-term; it will be lowered to a CFG.
+// This is a pseduo-term; it will be lowered to instructions in a CFG.
 class Let : public SExpr {
 public:
   static bool classof(const SExpr *E) { return E->opcode() == COP_Let; }
@@ -1631,14 +1762,15 @@ public:
   SExpr *body() { return Body.get(); }
   const SExpr *body() const { return Body.get(); }
 
-  template <class V> typename V::R_SExpr traverse(V &Visitor) {
+  template <class V>
+  typename V::R_SExpr traverse(V &Vs, typename V::R_Ctx Ctx) {
     // This is a variable declaration, so traverse the definition.
-    typename V::R_SExpr E0 = Visitor.traverse(VarDecl->Definition, TRV_Lazy);
+    auto E0 = Vs.traverse(VarDecl->Definition, Vs.subExprCtx(Ctx));
     // Tell the rewriter to enter the scope of the let variable.
-    Variable *Nvd = Visitor.enterScope(*VarDecl, E0);
-    typename V::R_SExpr E1 = Visitor.traverse(Body);
-    Visitor.exitScope(*VarDecl);
-    return Visitor.reduceLet(*this, Nvd, E1);
+    Variable *Nvd = Vs.enterScope(*VarDecl, E0);
+    auto E1 = Vs.traverse(Body, Ctx);
+    Vs.exitScope(*VarDecl);
+    return Vs.reduceLet(*this, Nvd, E1);
   }
 
   template <class C> typename C::CType compare(Let* E, C& Cmp) {

Modified: cfe/trunk/include/clang/Analysis/Analyses/ThreadSafetyTraverse.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Analysis/Analyses/ThreadSafetyTraverse.h?rev=209774&r1=209773&r2=209774&view=diff
==============================================================================
--- cfe/trunk/include/clang/Analysis/Analyses/ThreadSafetyTraverse.h (original)
+++ cfe/trunk/include/clang/Analysis/Analyses/ThreadSafetyTraverse.h Wed May 28 16:28:13 2014
@@ -45,33 +45,31 @@ namespace til {
 //       compute a result for a node of type X
 //
 // The reduceX methods control the kind of traversal (visitor, copy, etc.).
-// These are separated into a separate class R for the purpose of code reuse.
-// The full reducer interface also has methods to handle scopes
-template <class Self, class R> class Traversal : public R {
+// They are defined in derived classes.
+//
+// Class R defines the basic interface types (R_SExpr).
+template <class Self, class R>
+class Traversal {
 public:
-  Self *self() { return reinterpret_cast<Self *>(this); }
+  Self *self() { return static_cast<Self *>(this); }
 
   // Traverse an expression -- returning a result of type R_SExpr.
   // Override this method to do something for every expression, regardless
-  // of which kind it is.  TraversalKind indicates the context in which
-  // the expression occurs, and can be:
-  //   TRV_Normal
-  //   TRV_Lazy   -- e may need to be traversed lazily, using a Future.
-  //   TRV_Tail   -- e occurs in a tail position
-  typename R::R_SExpr traverse(SExprRef &E, TraversalKind K = TRV_Normal) {
-    return traverse(E.get(), K);
+  // of which kind it is.
+  typename R::R_SExpr traverse(SExprRef &E, typename R::R_Ctx Ctx) {
+    return traverse(E.get(), Ctx);
   }
 
-  typename R::R_SExpr traverse(SExpr *E, TraversalKind K = TRV_Normal) {
-    return traverseByCase(E);
+  typename R::R_SExpr traverse(SExpr *E, typename R::R_Ctx Ctx) {
+    return traverseByCase(E, Ctx);
   }
 
   // Helper method to call traverseX(e) on the appropriate type.
-  typename R::R_SExpr traverseByCase(SExpr *E) {
+  typename R::R_SExpr traverseByCase(SExpr *E, typename R::R_Ctx Ctx) {
     switch (E->opcode()) {
 #define TIL_OPCODE_DEF(X)                                                   \
     case COP_##X:                                                           \
-      return self()->traverse##X(cast<X>(E));
+      return self()->traverse##X(cast<X>(E), Ctx);
 #include "ThreadSafetyOps.def"
 #undef TIL_OPCODE_DEF
     }
@@ -80,41 +78,83 @@ public:
 // Traverse e, by static dispatch on the type "X" of e.
 // Override these methods to do something for a particular kind of term.
 #define TIL_OPCODE_DEF(X)                                                   \
-  typename R::R_SExpr traverse##X(X *e) { return e->traverse(*self()); }
+  typename R::R_SExpr traverse##X(X *e, typename R::R_Ctx Ctx) {            \
+    return e->traverse(*self(), Ctx);                                       \
+  }
 #include "ThreadSafetyOps.def"
 #undef TIL_OPCODE_DEF
 };
 
 
-// Implements a Reducer that makes a deep copy of an SExpr.
-// The default behavior of reduce##X(...) is to create a copy of the original.
-// Subclasses can override reduce##X to implement non-destructive rewriting
-// passes.
-class CopyReducer {
+// Base class for simple reducers that don't much care about the context.
+class SimpleReducerBase {
 public:
-  CopyReducer() {}
+  enum TraversalKind {
+    TRV_Normal,
+    TRV_Decl,
+    TRV_Lazy,
+    TRV_Type
+  };
+
+  // R_Ctx defines a "context" for the traversal, which encodes information
+  // about where a term appears.  This can be used to encoding the
+  // "current continuation" for CPS transforms, or other information.
+  typedef TraversalKind R_Ctx;
+
+  // Create context for an ordinary subexpression.
+  R_Ctx subExprCtx(R_Ctx Ctx) { return TRV_Normal; }
+
+  // Create context for a subexpression that occurs in a declaration position
+  // (e.g. function body).
+  R_Ctx declCtx(R_Ctx Ctx) { return TRV_Decl; }
+
+  // Create context for a subexpression that occurs in a position that
+  // should be reduced lazily.  (e.g. code body).
+  R_Ctx lazyCtx(R_Ctx Ctx) { return TRV_Lazy; }
+
+  // Create context for a subexpression that occurs in a type position.
+  R_Ctx typeCtx(R_Ctx Ctx) { return TRV_Type; }
+};
 
-  void setArena(MemRegionRef A) { Arena = A; }
 
+// Base class for traversals that rewrite an SExpr to another SExpr.
+class CopyReducerBase : public SimpleReducerBase {
+public:
   // R_SExpr is the result type for a traversal.
   // A copy or non-destructive rewrite returns a newly allocated term.
   typedef SExpr *R_SExpr;
+  typedef BasicBlock *R_BasicBlock;
 
   // Container is a minimal interface used to store results when traversing
   // SExprs of variable arity, such as Phi, Goto, and SCFG.
   template <class T> class Container {
   public:
     // Allocate a new container with a capacity for n elements.
-    Container(CopyReducer &R, unsigned N) : Elems(R.Arena, N) {}
+    Container(CopyReducerBase &S, unsigned N) : Elems(S.Arena, N) {}
 
     // Push a new element onto the container.
     void push_back(T E) { Elems.push_back(E); }
 
-  private:
-    friend class CopyReducer;
     SimpleArray<T> Elems;
   };
 
+  CopyReducerBase(MemRegionRef A) : Arena(A) {}
+
+protected:
+  MemRegionRef Arena;
+};
+
+
+// Implements a traversal that makes a deep copy of an SExpr.
+// The default behavior of reduce##X(...) is to create a copy of the original.
+// Subclasses can override reduce##X to implement non-destructive rewriting
+// passes.
+template<class Self>
+class CopyReducer : public Traversal<Self, CopyReducerBase>,
+                    public CopyReducerBase {
+public:
+  CopyReducer(MemRegionRef A) : CopyReducerBase(A) {}
+
 public:
   R_SExpr reduceNull() {
     return nullptr;
@@ -131,6 +171,10 @@ public:
   R_SExpr reduceLiteral(Literal &Orig) {
     return new (Arena) Literal(Orig);
   }
+  template<class T>
+  R_SExpr reduceLiteralT(LiteralT<T> &Orig) {
+    return new (Arena) LiteralT<T>(Orig);
+  }
   R_SExpr reduceLiteralPtr(LiteralPtr &Orig) {
     return new (Arena) LiteralPtr(Orig);
   }
@@ -170,8 +214,8 @@ public:
   R_SExpr reduceStore(Store &Orig, R_SExpr E0, R_SExpr E1) {
     return new (Arena) Store(Orig, E0, E1);
   }
-  R_SExpr reduceArrayFirst(ArrayFirst &Orig, R_SExpr E0) {
-    return new (Arena) ArrayFirst(Orig, E0);
+  R_SExpr reduceArrayIndex(ArrayIndex &Orig, R_SExpr E0, R_SExpr E1) {
+    return new (Arena) ArrayIndex(Orig, E0, E1);
   }
   R_SExpr reduceArrayAdd(ArrayAdd &Orig, R_SExpr E0, R_SExpr E1) {
     return new (Arena) ArrayAdd(Orig, E0, E1);
@@ -187,16 +231,20 @@ public:
   }
 
   R_SExpr reduceSCFG(SCFG &Orig, Container<BasicBlock *> &Bbs) {
-    return new (Arena) SCFG(Orig, std::move(Bbs.Elems));
+    return nullptr;  // FIXME: implement CFG rewriting
+  }
+  R_BasicBlock reduceBasicBlock(BasicBlock &Orig, Container<Variable *> &As,
+                                Container<Variable *> &Is, R_SExpr T) {
+    return nullptr;  // FIXME: implement CFG rewriting
   }
   R_SExpr reducePhi(Phi &Orig, Container<R_SExpr> &As) {
     return new (Arena) Phi(Orig, std::move(As.Elems));
   }
-  R_SExpr reduceGoto(Goto &Orig, BasicBlock *B, unsigned Index) {
-    return new (Arena) Goto(Orig, B, Index);
+  R_SExpr reduceGoto(Goto &Orig, BasicBlock *B) {
+    return new (Arena) Goto(Orig, B, 0);  // FIXME: set index
   }
   R_SExpr reduceBranch(Branch &O, R_SExpr C, BasicBlock *B0, BasicBlock *B1) {
-    return new (Arena) Branch(O, C, B0, B1);
+    return new (Arena) Branch(O, C, B0, B1, 0, 0);  // FIXME: set indices
   }
 
   R_SExpr reduceIdentifier(Identifier &Orig) {
@@ -209,12 +257,6 @@ public:
     return new (Arena) Let(Orig, Nvd, B);
   }
 
-  BasicBlock *reduceBasicBlock(BasicBlock &Orig, Container<Variable *> &As,
-                               Container<Variable *> &Is, R_SExpr T) {
-    return new (Arena) BasicBlock(Orig, std::move(As.Elems),
-                                        std::move(Is.Elems), T);
-  }
-
   // Create a new variable from orig, and push it onto the lexical scope.
   Variable *enterScope(Variable &Orig, R_SExpr E0) {
     return new (Arena) Variable(Orig, E0);
@@ -224,49 +266,57 @@ public:
 
   void enterCFG(SCFG &Cfg) {}
   void exitCFG(SCFG &Cfg) {}
+  void enterBasicBlock(BasicBlock &BB) {}
+  void exitBasicBlock(BasicBlock &BB) {}
 
   // Map Variable references to their rewritten definitions.
   Variable *reduceVariableRef(Variable *Ovd) { return Ovd; }
 
-  // Map BasicBlock references to their rewritten defs.
+  // Map BasicBlock references to their rewritten definitions.
   BasicBlock *reduceBasicBlockRef(BasicBlock *Obb) { return Obb; }
-
-private:
-  MemRegionRef Arena;
 };
 
 
-class SExprCopier : public Traversal<SExprCopier, CopyReducer> {
+class SExprCopier : public CopyReducer<SExprCopier> {
 public:
-  SExprCopier(MemRegionRef A) { setArena(A); }
+  typedef SExpr *R_SExpr;
+
+  SExprCopier(MemRegionRef A) : CopyReducer(A) { }
 
   // Create a copy of e in region a.
   static SExpr *copy(SExpr *E, MemRegionRef A) {
     SExprCopier Copier(A);
-    return Copier.traverse(E);
+    return Copier.traverse(E, TRV_Normal);
   }
 };
 
 
-// Implements a Reducer that visits each subexpression, and returns either
-// true or false.
-class VisitReducer {
-public:
-  VisitReducer() {}
 
+// Base class for visit traversals.
+class VisitReducerBase : public SimpleReducerBase {
+public:
   // A visitor returns a bool, representing success or failure.
   typedef bool R_SExpr;
+  typedef bool R_BasicBlock;
 
   // A visitor "container" is a single bool, which accumulates success.
   template <class T> class Container {
   public:
-    Container(VisitReducer &R, unsigned N) : Success(true) {}
+    Container(VisitReducerBase &S, unsigned N) : Success(true) {}
     void push_back(bool E) { Success = Success && E; }
 
-  private:
-    friend class VisitReducer;
     bool Success;
   };
+};
+
+
+// Implements a traversal that visits each subexpression, and returns either
+// true or false.
+template <class Self>
+class VisitReducer : public Traversal<Self, VisitReducerBase>,
+                     public VisitReducerBase {
+public:
+  VisitReducer() {}
 
 public:
   R_SExpr reduceNull() { return true; }
@@ -274,6 +324,8 @@ public:
   R_SExpr reduceWildcard(Wildcard &Orig) { return true; }
 
   R_SExpr reduceLiteral(Literal &Orig) { return true; }
+  template<class T>
+  R_SExpr reduceLiteralT(LiteralT<T> &Orig) { return true; }
   R_SExpr reduceLiteralPtr(Literal &Orig) { return true; }
 
   R_SExpr reduceFunction(Function &Orig, Variable *Nvd, R_SExpr E0) {
@@ -299,7 +351,9 @@ public:
   R_SExpr reduceAlloc(Alloc &Orig, R_SExpr E0) { return E0; }
   R_SExpr reduceLoad(Load &Orig, R_SExpr E0) { return E0; }
   R_SExpr reduceStore(Store &Orig, R_SExpr E0, R_SExpr E1) { return E0 && E1; }
-  R_SExpr reduceArrayFirst(Store &Orig, R_SExpr E0) { return E0; }
+  R_SExpr reduceArrayIndex(Store &Orig, R_SExpr E0, R_SExpr E1) {
+    return E0 && E1;
+  }
   R_SExpr reduceArrayAdd(Store &Orig, R_SExpr E0, R_SExpr E1) {
     return E0 && E1;
   }
@@ -312,10 +366,14 @@ public:
   R_SExpr reduceSCFG(SCFG &Orig, Container<BasicBlock *> Bbs) {
     return Bbs.Success;
   }
-   R_SExpr reducePhi(Phi &Orig, Container<R_SExpr> &As) {
+  R_BasicBlock reduceBasicBlock(BasicBlock &Orig, Container<Variable *> &As,
+                                Container<Variable *> &Is, R_SExpr T) {
+    return (As.Success && Is.Success && T);
+  }
+  R_SExpr reducePhi(Phi &Orig, Container<R_SExpr> &As) {
     return As.Success;
   }
-  R_SExpr reduceGoto(Goto &Orig, BasicBlock *B, unsigned Index) {
+  R_SExpr reduceGoto(Goto &Orig, BasicBlock *B) {
     return true;
   }
   R_SExpr reduceBranch(Branch &O, R_SExpr C, BasicBlock *B0, BasicBlock *B1) {
@@ -332,39 +390,25 @@ public:
     return Nvd && B;
   }
 
-  BasicBlock *reduceBasicBlock(BasicBlock &Orig, Container<Variable *> &As,
-                               Container<Variable *> &Is, R_SExpr T) {
-    return (As.Success && Is.Success && T) ? &Orig : nullptr;
-  }
-
-  Variable *enterScope(Variable &Orig, R_SExpr E0) {
-    return E0 ? &Orig : nullptr;
-  }
+  Variable *enterScope(Variable &Orig, R_SExpr E0) { return &Orig; }
   void exitScope(const Variable &Orig) {}
-
   void enterCFG(SCFG &Cfg) {}
   void exitCFG(SCFG &Cfg) {}
+  void enterBasicBlock(BasicBlock &BB) {}
+  void exitBasicBlock(BasicBlock &BB) {}
 
-  Variable *reduceVariableRef(Variable *Ovd) { return Ovd; }
-
+  Variable   *reduceVariableRef  (Variable *Ovd)   { return Ovd; }
   BasicBlock *reduceBasicBlockRef(BasicBlock *Obb) { return Obb; }
-};
 
-
-// A visitor will visit each node, and halt if any reducer returns false.
-template <class Self>
-class SExprVisitor : public Traversal<Self, VisitReducer> {
 public:
-  SExprVisitor() : Success(true) {}
-
   bool traverse(SExpr *E, TraversalKind K = TRV_Normal) {
     Success = Success && this->traverseByCase(E);
     return Success;
   }
 
   static bool visit(SExpr *E) {
-    SExprVisitor Visitor;
-    return Visitor.traverse(E);
+    Self Visitor;
+    return Visitor.traverse(E, TRV_Normal);
   }
 
 private:
@@ -454,6 +498,8 @@ protected:
     }
     SS << "BB_";
     SS << BB->blockID();
+    SS << ":";
+    SS << index;
   }
 
   // TODO: further distinguish between binary operations.
@@ -488,7 +534,7 @@ protected:
       case COP_Alloc:      return Prec_Other;
       case COP_Load:       return Prec_Postfix;
       case COP_Store:      return Prec_Other;
-      case COP_ArrayFirst: return Prec_Postfix;
+      case COP_ArrayIndex: return Prec_Postfix;
       case COP_ArrayAdd:   return Prec_Postfix;
 
       case COP_UnaryOp:    return Prec_Unary;
@@ -496,6 +542,7 @@ protected:
       case COP_Cast:       return Prec_Unary;
 
       case COP_SCFG:       return Prec_Decl;
+      case COP_BasicBlock: return Prec_MAX;
       case COP_Phi:        return Prec_Atom;
       case COP_Goto:       return Prec_Atom;
       case COP_Branch:     return Prec_Atom;
@@ -614,7 +661,7 @@ protected:
       }
       case ValueType::BT_String: {
         SS << "\"";
-        printLiteralT(reinterpret_cast<LiteralT<bool>*>(E), SS);
+        printLiteralT(reinterpret_cast<LiteralT<StringRef>*>(E), SS);
         SS << "\"";
         return;
       }
@@ -755,15 +802,11 @@ protected:
     self()->printSExpr(E->source(), SS, Prec_Other-1);
   }
 
-  void printArrayFirst(ArrayFirst *E, StreamType &SS) {
+  void printArrayIndex(ArrayIndex *E, StreamType &SS) {
     self()->printSExpr(E->array(), SS, Prec_Postfix);
-    if (ArrayAdd *A = dyn_cast_or_null<ArrayAdd>(E->array())) {
-      SS << "[";
-      printSExpr(A->index(), SS, Prec_MAX);
-      SS << "]";
-      return;
-    }
-    SS << "[0]";
+    SS << "[";
+    self()->printSExpr(E->index(), SS, Prec_MAX);
+    SS << "]";
   }
 
   void printArrayAdd(ArrayAdd *E, StreamType &SS) {
@@ -789,37 +832,43 @@ protected:
   }
 
   void printSCFG(SCFG *E, StreamType &SS) {
-    SS << "#CFG {\n";
+    SS << "CFG {\n";
     for (auto BBI : *E) {
-      SS << "BB_" << BBI->blockID() << ":";
+      printBasicBlock(BBI, SS);
+    }
+    SS << "}";
+    newline(SS);
+  }
+
+  void printBasicBlock(BasicBlock *E, StreamType &SS) {
+    SS << "BB_" << E->blockID() << ":";
+    if (E->parent())
+      SS << " BB_" << E->parent()->blockID();
+    newline(SS);
+    for (auto A : E->arguments()) {
+      SS << "let ";
+      self()->printVariable(A, SS, true);
+      SS << " = ";
+      self()->printSExpr(A->definition(), SS, Prec_MAX);
+      SS << ";";
       newline(SS);
-      for (auto A : BBI->arguments()) {
+    }
+    for (auto I : E->instructions()) {
+      if (I->definition()->opcode() != COP_Store) {
         SS << "let ";
-        self()->printVariable(A, SS, true);
+        self()->printVariable(I, SS, true);
         SS << " = ";
-        self()->printSExpr(A->definition(), SS, Prec_MAX);
-        SS << ";";
-        newline(SS);
-      }
-      for (auto I : BBI->instructions()) {
-        if (I->definition()->opcode() != COP_Store) {
-          SS << "let ";
-          self()->printVariable(I, SS, true);
-          SS << " = ";
-        }
-        self()->printSExpr(I->definition(), SS, Prec_MAX);
-        SS << ";";
-        newline(SS);
-      }
-      SExpr *T = BBI->terminator();
-      if (T) {
-        self()->printSExpr(T, SS, Prec_MAX);
-        SS << ";";
-        newline(SS);
       }
+      self()->printSExpr(I->definition(), SS, Prec_MAX);
+      SS << ";";
+      newline(SS);
+    }
+    SExpr *T = E->terminator();
+    if (T) {
+      self()->printSExpr(T, SS, Prec_MAX);
+      SS << ";";
       newline(SS);
     }
-    SS << "}";
     newline(SS);
   }
 

Modified: cfe/trunk/include/clang/Analysis/Analyses/ThreadSafetyUtil.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Analysis/Analyses/ThreadSafetyUtil.h?rev=209774&r1=209773&r2=209774&view=diff
==============================================================================
--- cfe/trunk/include/clang/Analysis/Analyses/ThreadSafetyUtil.h (original)
+++ cfe/trunk/include/clang/Analysis/Analyses/ThreadSafetyUtil.h Wed May 28 16:28:13 2014
@@ -109,8 +109,9 @@ public:
     return *this;
   }
 
+  // Reserve space for at least Ncp items, reallocating if necessary.
   void reserve(size_t Ncp, MemRegionRef A) {
-    if (Ncp < Capacity)
+    if (Ncp <= Capacity)
       return;
     T *Odata = Data;
     Data = A.allocateT<T>(Ncp);
@@ -119,6 +120,14 @@ public:
     return;
   }
 
+  // Reserve space for at least N more items.
+  void reserveCheck(size_t N, MemRegionRef A) {
+    if (Capacity == 0)
+      reserve(InitialCapacity, A);
+    else if (Size + N < Capacity)
+      reserve(Capacity*2, A);
+  }
+
   typedef T *iterator;
   typedef const T *const_iterator;
 
@@ -163,6 +172,8 @@ public:
   }
 
 private:
+  static const unsigned InitialCapacity = 4;
+
   SimpleArray(const SimpleArray<T> &A) LLVM_DELETED_FUNCTION;
 
   T *Data;

Modified: cfe/trunk/lib/Analysis/ThreadSafetyCommon.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Analysis/ThreadSafetyCommon.cpp?rev=209774&r1=209773&r2=209774&view=diff
==============================================================================
--- cfe/trunk/lib/Analysis/ThreadSafetyCommon.cpp (original)
+++ cfe/trunk/lib/Analysis/ThreadSafetyCommon.cpp Wed May 28 16:28:13 2014
@@ -384,8 +384,7 @@ SExprBuilder::translateArraySubscriptExp
                                           CallingContext *Ctx) {
   til::SExpr *E0 = translate(E->getBase(), Ctx);
   til::SExpr *E1 = translate(E->getIdx(), Ctx);
-  auto *AA = new (Arena) til::ArrayAdd(E0, E1);
-  return new (Arena) til::ArrayFirst(AA);
+  return new (Arena) til::ArrayIndex(E0, E1);
 }
 
 
@@ -628,7 +627,8 @@ void SExprBuilder::enterCFG(CFG *Cfg, co
   BlockMap.resize(NBlocks, nullptr);
   // create map from clang blockID to til::BasicBlocks
   for (auto *B : *Cfg) {
-    auto *BB = new (Arena) til::BasicBlock(Arena, 0, B->size());
+    auto *BB = new (Arena) til::BasicBlock(Arena);
+    BB->reserveInstructions(B->size());
     BlockMap[B->getBlockID()] = BB;
   }
   CallCtx.reset(new SExprBuilder::CallingContext(D));
@@ -654,7 +654,7 @@ void SExprBuilder::enterCFG(CFG *Cfg, co
 void SExprBuilder::enterCFGBlock(const CFGBlock *B) {
   // Intialize TIL basic block and add it to the CFG.
   CurrentBB = lookupBlock(B);
-  CurrentBB->setNumPredecessors(B->pred_size());
+  CurrentBB->reservePredecessors(B->pred_size());
   Scfg->add(CurrentBB);
 
   CurrentBlockInfo = &BBInfo[B->getBlockID()];
@@ -668,6 +668,7 @@ void SExprBuilder::enterCFGBlock(const C
 void SExprBuilder::handlePredecessor(const CFGBlock *Pred) {
   // Compute CurrentLVarMap on entry from ExitMaps of predecessors
 
+  CurrentBB->addPredecessor(BlockMap[Pred->getBlockID()]);
   BlockInfo *PredInfo = &BBInfo[Pred->getBlockID()];
   assert(PredInfo->UnprocessedSuccessors > 0);
 
@@ -724,7 +725,8 @@ void SExprBuilder::exitCFGBlockBody(cons
   if (N == 1) {
     til::BasicBlock *BB = *It ? lookupBlock(*It) : nullptr;
     // TODO: set index
-    til::SExpr *Tm = new (Arena) til::Goto(BB, 0);
+    unsigned Idx = BB->findPredecessorIndex(CurrentBB);
+    til::SExpr *Tm = new (Arena) til::Goto(BB, Idx);
     CurrentBB->setTerminator(Tm);
   }
   else if (N == 2) {
@@ -732,8 +734,9 @@ void SExprBuilder::exitCFGBlockBody(cons
     til::BasicBlock *BB1 = *It ? lookupBlock(*It) : nullptr;
     ++It;
     til::BasicBlock *BB2 = *It ? lookupBlock(*It) : nullptr;
-    // TODO: set conditional, set index
-    til::SExpr *Tm = new (Arena) til::Branch(C, BB1, BB2);
+    unsigned Idx1 = BB1 ? BB1->findPredecessorIndex(CurrentBB) : 0;
+    unsigned Idx2 = BB2 ? BB2->findPredecessorIndex(CurrentBB) : 0;
+    til::SExpr *Tm = new (Arena) til::Branch(C, BB1, BB2, Idx1, Idx2);
     CurrentBB->setTerminator(Tm);
   }
 }

Modified: cfe/trunk/lib/Analysis/ThreadSafetyTIL.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Analysis/ThreadSafetyTIL.cpp?rev=209774&r1=209773&r2=209774&view=diff
==============================================================================
--- cfe/trunk/lib/Analysis/ThreadSafetyTIL.cpp (original)
+++ cfe/trunk/lib/Analysis/ThreadSafetyTIL.cpp Wed May 28 16:28:13 2014
@@ -48,6 +48,46 @@ StringRef getBinaryOpcodeString(TIL_Bina
 }
 
 
+unsigned BasicBlock::addPredecessor(BasicBlock *Pred) {
+  unsigned Idx = Predecessors.size();
+  Predecessors.reserveCheck(1, Arena);
+  Predecessors.push_back(Pred);
+  for (Variable *V : Args) {
+    if (Phi* Ph = dyn_cast<Phi>(V->definition())) {
+      Ph->values().reserveCheck(1, Arena);
+      Ph->values().push_back(nullptr);
+    }
+  }
+  return Idx;
+}
+
+void BasicBlock::reservePredecessors(unsigned NumPreds) {
+  Predecessors.reserve(NumPreds, Arena);
+  for (Variable *V : Args) {
+    if (Phi* Ph = dyn_cast<Phi>(V->definition())) {
+      Ph->values().reserve(NumPreds, Arena);
+    }
+  }
+}
+
+void BasicBlock::renumberVars() {
+  unsigned VID = 0;
+  for (Variable *V : Args) {
+    V->setID(BlockID, VID++);
+  }
+  for (Variable *V : Instrs) {
+    V->setID(BlockID, VID++);
+  }
+}
+
+void SCFG::renumberVars() {
+  for (BasicBlock *B : Blocks) {
+    B->renumberVars();
+  }
+}
+
+
+
 
 // If E is a variable, then trace back through any aliases or redundant
 // Phi nodes to find the canonical definition.





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