Introduce a new concept to the static analyzer: SValuator.

GRTransferFuncs had the conflated role of both constructing SVals (symbolic
expressions) as well as handling checker-specific logic. Now SValuator has the
role of constructing SVals from expressions and GRTransferFuncs just handles
checker-specific logic. The motivation is by separating these two concepts we
will be able to much more easily create richer constraint-generating logic
without coupling it to the main checker transfer function logic.

We now have one implementation of SValuator: SimpleSValuator.

SimpleSValuator is essentially the SVal-related logic that was in GRSimpleVals
(which is removed in this patch). This includes the logic for EvalBinOp,
EvalCast, etc. Because SValuator has a narrower role than the old
GRTransferFuncs, the interfaces are much simpler, and so is the implementation
of SimpleSValuator compared to GRSimpleVals. I also did a line-by-line review of
SVal-related logic in GRSimpleVals and cleaned it up while moving it over to
SimpleSValuator.

As a consequence of removing GRSimpleVals, there is no longer a
'-checker-simple' option. The '-checker-cfref' did everything that option did
but also ran the retain/release checker. Of course a user may not always wish to
run the retain/release checker, nor do we wish core analysis logic buried in the
checker-specific logic. The next step is to refactor the logic in CFRefCount.cpp
to separate out these pieces into the core analysis engine.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@74229 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 0 insertions, 414 deletions

diff --git a/lib/Analysis/GRSimpleVals.cpp b/lib/Analysis/GRSimpleVals.cpp
deleted file mode 100644
index 9a1b2fc05e..0000000000
--- a/lib/Analysis/GRSimpleVals.cpp
+++ /dev/null
@@ -1,414 +0,0 @@
-// GRSimpleVals.cpp - Transfer functions for tracking simple values -*- C++ -*--
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-//  This file defines GRSimpleVals, a sub-class of GRTransferFuncs that
-//  provides transfer functions for performing simple value tracking with
-//  limited support for symbolics.
-//
-//===----------------------------------------------------------------------===//
-
-#include "GRSimpleVals.h"
-#include "BasicObjCFoundationChecks.h"
-#include "clang/Basic/SourceManager.h"
-#include "clang/Analysis/PathDiagnostic.h"
-#include "clang/Analysis/PathSensitive/GRState.h"
-#include "clang/Analysis/PathSensitive/BugReporter.h"
-#include "clang/Analysis/LocalCheckers.h"
-#include "clang/Analysis/PathSensitive/GRExprEngine.h"
-#include "llvm/Support/Compiler.h"
-#include <sstream>
-
-using namespace clang;
-
-//===----------------------------------------------------------------------===//
-// Transfer Function creation for External clients.
-//===----------------------------------------------------------------------===//
-
-GRTransferFuncs* clang::MakeGRSimpleValsTF() { return new GRSimpleVals(); }  
-
-//===----------------------------------------------------------------------===//
-// Transfer function for Casts.
-//===----------------------------------------------------------------------===//
-
-SVal GRSimpleVals::EvalCast(GRExprEngine& Eng, NonLoc X, QualType T) {
-  
-  if (!isa<nonloc::ConcreteInt>(X))
-    return UnknownVal();
-
-  bool isLocType = Loc::IsLocType(T);
-  
-  // Only handle casts from integers to integers.
-  if (!isLocType && !T->isIntegerType())
-    return UnknownVal();
-  
-  BasicValueFactory& BasicVals = Eng.getBasicVals();
-  
-  llvm::APSInt V = cast<nonloc::ConcreteInt>(X).getValue();
-  V.setIsUnsigned(T->isUnsignedIntegerType() || Loc::IsLocType(T));
-  V.extOrTrunc(Eng.getContext().getTypeSize(T));
-  
-  if (isLocType)
-    return loc::ConcreteInt(BasicVals.getValue(V));
-  else
-    return nonloc::ConcreteInt(BasicVals.getValue(V));
-}
-
-// Casts.
-
-SVal GRSimpleVals::EvalCast(GRExprEngine& Eng, Loc X, QualType T) {
-  
-  // Casts from pointers -> pointers, just return the lval.
-  //
-  // Casts from pointers -> references, just return the lval.  These
-  //   can be introduced by the frontend for corner cases, e.g
-  //   casting from va_list* to __builtin_va_list&.
-  //
-  assert (!X.isUnknownOrUndef());
-  
-  if (Loc::IsLocType(T) || T->isReferenceType())
-    return X;
-  
-  // FIXME: Handle transparent unions where a value can be "transparently"
-  //  lifted into a union type.
-  if (T->isUnionType())
-    return UnknownVal();
-  
-  assert (T->isIntegerType());
-  BasicValueFactory& BasicVals = Eng.getBasicVals();
-  unsigned BitWidth = Eng.getContext().getTypeSize(T);
-
-  if (!isa<loc::ConcreteInt>(X))
-    return Eng.getValueManager().makeLocAsInteger(X, BitWidth);
-  
-  llvm::APSInt V = cast<loc::ConcreteInt>(X).getValue();
-  V.setIsUnsigned(T->isUnsignedIntegerType() || Loc::IsLocType(T));
-  V.extOrTrunc(BitWidth);
-  return nonloc::ConcreteInt(BasicVals.getValue(V));
-}
-
-// Unary operators.
-
-SVal GRSimpleVals::EvalMinus(GRExprEngine& Eng, UnaryOperator* U, NonLoc X){
-  
-  switch (X.getSubKind()) {
-      
-    case nonloc::ConcreteIntKind:
-      return cast<nonloc::ConcreteInt>(X).EvalMinus(Eng.getBasicVals(), U);
-      
-    default:
-      return UnknownVal();
-  }
-}
-
-SVal GRSimpleVals::EvalComplement(GRExprEngine& Eng, NonLoc X) {
-
-  switch (X.getSubKind()) {
-      
-    case nonloc::ConcreteIntKind:
-      return cast<nonloc::ConcreteInt>(X).EvalComplement(Eng.getBasicVals());
-      
-    default:
-      return UnknownVal();
-  }
-}
-
-// Binary operators.
-
-static unsigned char LNotOpMap[] = {
-  (unsigned char) BinaryOperator::GE,  /* LT => GE */
-  (unsigned char) BinaryOperator::LE,  /* GT => LE */
-  (unsigned char) BinaryOperator::GT,  /* LE => GT */
-  (unsigned char) BinaryOperator::LT,  /* GE => LT */
-  (unsigned char) BinaryOperator::NE,  /* EQ => NE */
-  (unsigned char) BinaryOperator::EQ   /* NE => EQ */
-};
-
-SVal GRSimpleVals::DetermEvalBinOpNN(GRExprEngine& Eng,
-                                     BinaryOperator::Opcode Op,
-                                     NonLoc L, NonLoc R,
-                                     QualType T)  {
-  BasicValueFactory& BasicVals = Eng.getBasicVals();
-  ValueManager& ValMgr = Eng.getValueManager();
-  unsigned subkind = L.getSubKind();
-  
-  while (1) {
-    
-    switch (subkind) {
-      default:
-        return UnknownVal();
-        
-      case nonloc::LocAsIntegerKind: {
-        Loc LL = cast<nonloc::LocAsInteger>(L).getLoc();        
-        
-        switch (R.getSubKind()) {
-          case nonloc::LocAsIntegerKind:
-            return EvalBinOp(Eng, Op, LL,
-                             cast<nonloc::LocAsInteger>(R).getLoc());
-            
-          case nonloc::ConcreteIntKind: {
-            // Transform the integer into a location and compare.
-            ASTContext& Ctx = Eng.getContext();
-            llvm::APSInt V = cast<nonloc::ConcreteInt>(R).getValue();
-            V.setIsUnsigned(true);
-            V.extOrTrunc(Ctx.getTypeSize(Ctx.VoidPtrTy));
-            return EvalBinOp(Eng, Op, LL, ValMgr.makeLoc(V));
-          }
-          
-          default: 
-            switch (Op) {
-              case BinaryOperator::EQ:
-                return ValMgr.makeTruthVal(false);
-              case BinaryOperator::NE:
-                return ValMgr.makeTruthVal(true);
-              default:
-                // This case also handles pointer arithmetic.
-                return UnknownVal();
-            }
-        }
-      }
-        
-      case nonloc::SymExprValKind: {
-        // Logical not?        
-        if (!(Op == BinaryOperator::EQ && R.isZeroConstant()))
-          return UnknownVal();
-
-        const SymExpr &SE=*cast<nonloc::SymExprVal>(L).getSymbolicExpression();
-        
-        // Only handle ($sym op constant) for now.
-        if (const SymIntExpr *E = dyn_cast<SymIntExpr>(&SE)) {
-          BinaryOperator::Opcode Opc = E->getOpcode();
-        
-          if (Opc < BinaryOperator::LT || Opc > BinaryOperator::NE)
-            return UnknownVal();
-
-          // For comparison operators, translate the constraint by
-          // changing the opcode.        
-          int idx = (unsigned) Opc - (unsigned) BinaryOperator::LT;
-        
-          assert (idx >= 0 && 
-                  (unsigned) idx < sizeof(LNotOpMap)/sizeof(unsigned char));
-        
-          Opc = (BinaryOperator::Opcode) LNotOpMap[idx];          
-          assert(E->getType(Eng.getContext()) == T);
-          E = Eng.getSymbolManager().getSymIntExpr(E->getLHS(), Opc,
-                                                   E->getRHS(), T);
-          return nonloc::SymExprVal(E);
-        }
-        
-        return UnknownVal();
-      }
-        
-      case nonloc::ConcreteIntKind:
-        
-        if (isa<nonloc::ConcreteInt>(R)) {          
-          const nonloc::ConcreteInt& L_CI = cast<nonloc::ConcreteInt>(L);
-          const nonloc::ConcreteInt& R_CI = cast<nonloc::ConcreteInt>(R);
-          return L_CI.EvalBinOp(BasicVals, Op, R_CI);          
-        }
-        else {
-          subkind = R.getSubKind();
-          NonLoc tmp = R;
-          R = L;
-          L = tmp;
-          
-          // Swap the operators.
-          switch (Op) {
-            case BinaryOperator::LT: Op = BinaryOperator::GT; break;
-            case BinaryOperator::GT: Op = BinaryOperator::LT; break;
-            case BinaryOperator::LE: Op = BinaryOperator::GE; break;
-            case BinaryOperator::GE: Op = BinaryOperator::LE; break;
-            default: break;
-          }
-          
-          continue;
-        }
-        
-      case nonloc::SymbolValKind:
-        if (isa<nonloc::ConcreteInt>(R)) {
-          ValueManager &ValMgr = Eng.getValueManager();
-          return ValMgr.makeNonLoc(cast<nonloc::SymbolVal>(L).getSymbol(), Op,
-                                   cast<nonloc::ConcreteInt>(R).getValue(), T);
-        }
-        else
-          return UnknownVal();
-    }
-  }
-}
-
-
-// Binary Operators (except assignments and comma).
-
-SVal GRSimpleVals::EvalBinOp(GRExprEngine& Eng, BinaryOperator::Opcode Op,
-                             Loc L, Loc R) {
-  
-  switch (Op) {
-    default:
-      return UnknownVal();      
-    case BinaryOperator::EQ:
-    case BinaryOperator::NE:
-      return EvalEquality(Eng, L, R, Op == BinaryOperator::EQ);
-  }
-}
-
-SVal GRSimpleVals::EvalBinOp(GRExprEngine& Eng, const GRState *state, 
-                             BinaryOperator::Opcode Op, Loc L, NonLoc R) {
-  
-  // Special case: 'R' is an integer that has the same width as a pointer and
-  // we are using the integer location in a comparison.  Normally this cannot be
-  // triggered, but transfer functions like those for OSCommpareAndSwapBarrier32
-  // can generate comparisons that trigger this code.
-  // FIXME: Are all locations guaranteed to have pointer width?
-  if (BinaryOperator::isEqualityOp(Op)) {
-    if (nonloc::ConcreteInt *RInt = dyn_cast<nonloc::ConcreteInt>(&R)) {
-      const llvm::APSInt *X = &RInt->getValue();
-      ASTContext &C = Eng.getContext();
-      if (C.getTypeSize(C.VoidPtrTy) == X->getBitWidth()) {
-        // Convert the signedness of the integer (if necessary).
-        if (X->isSigned())
-          X = &Eng.getBasicVals().getValue(*X, true);          
-        
-        return EvalBinOp(Eng, Op, L, loc::ConcreteInt(*X));
-      }
-    }
-  }
-  
-  // Delegate pointer arithmetic to store manager.
-  return Eng.getStoreManager().EvalBinOp(state, Op, L, R);
-}
-
-// Equality operators for Locs.  
-// FIXME: All this logic will be revamped when we have MemRegion::getLocation()
-// implemented.
-
-SVal GRSimpleVals::EvalEquality(GRExprEngine& Eng, Loc L, Loc R, bool isEqual) {
-  
-  ValueManager& ValMgr = Eng.getValueManager();
-
-  switch (L.getSubKind()) {
-
-    default:
-      assert(false && "EQ/NE not implemented for this Loc.");
-      return UnknownVal();
-      
-    case loc::ConcreteIntKind:
-
-      if (isa<loc::ConcreteInt>(R)) {
-        bool b = cast<loc::ConcreteInt>(L).getValue() ==
-                 cast<loc::ConcreteInt>(R).getValue();
-        
-        // Are we computing '!='?  Flip the result.
-        if (!isEqual)
-          b = !b;
-        
-        return ValMgr.makeTruthVal(b);
-      }
-      else if (SymbolRef Sym = R.getAsSymbol()) {
-        const SymIntExpr * SE =
-        Eng.getSymbolManager().getSymIntExpr(Sym,
-                                             isEqual ? BinaryOperator::EQ
-                                                     : BinaryOperator::NE,
-                                             cast<loc::ConcreteInt>(L).getValue(),
-                                             Eng.getContext().IntTy);
-        return nonloc::SymExprVal(SE);
-      }
-      
-      break;
-      
-    case loc::MemRegionKind: {
-      if (SymbolRef LSym = L.getAsLocSymbol()) {
-        if (isa<loc::ConcreteInt>(R)) {
-          const SymIntExpr *SE =
-            Eng.getSymbolManager().getSymIntExpr(LSym,
-                                           isEqual ? BinaryOperator::EQ
-                                                   : BinaryOperator::NE,
-                                           cast<loc::ConcreteInt>(R).getValue(),
-                                           Eng.getContext().IntTy);
-        
-          return nonloc::SymExprVal(SE);
-        }
-      }
-    }    
-    
-    // Fall-through.
-      
-    case loc::GotoLabelKind:
-      return ValMgr.makeTruthVal(isEqual ? L == R : L != R);
-  }
-  
-  return ValMgr.makeTruthVal(isEqual ? false : true);
-}
-
-//===----------------------------------------------------------------------===//
-// Transfer function for function calls.
-//===----------------------------------------------------------------------===//
-
-void GRSimpleVals::EvalCall(ExplodedNodeSet<GRState>& Dst,
-                            GRExprEngine& Eng,
-                            GRStmtNodeBuilder<GRState>& Builder,
-                            CallExpr* CE, SVal L,
-                            ExplodedNode<GRState>* Pred) {
-  
-  const GRState* state = Builder.GetState(Pred);
-  
-  // Invalidate all arguments passed in by reference (Locs).
-
-  for (CallExpr::arg_iterator I = CE->arg_begin(), E = CE->arg_end();
-        I != E; ++I) {
-
-    SVal V = state->getSVal(*I);
-    
-    if (isa<loc::MemRegionVal>(V)) {
-      const MemRegion *R = cast<loc::MemRegionVal>(V).getRegion();
-      
-      if (R->isBoundable())
-        state = state->bindLoc(cast<Loc>(V), UnknownVal());
-    } else if (isa<nonloc::LocAsInteger>(V))
-        state = state->bindLoc(cast<nonloc::LocAsInteger>(V).getLoc(),
-                               UnknownVal());
-  }
-  
-  // Make up a symbol for the return value of this function.  
-  // FIXME: We eventually should handle structs and other compound types
-  // that are returned by value.
-  QualType T = CE->getType();  
-  if (Loc::IsLocType(T) || (T->isIntegerType() && T->isScalarType())) {    
-    unsigned Count = Builder.getCurrentBlockCount();
-    SVal X = Eng.getValueManager().getConjuredSymbolVal(CE, Count);
-    state = state->bindExpr(CE, X, Eng.getCFG().isBlkExpr(CE), false);
-  }  
-    
-  Builder.MakeNode(Dst, CE, Pred, state);
-}
-
-//===----------------------------------------------------------------------===//
-// Transfer function for Objective-C message expressions.
-//===----------------------------------------------------------------------===//
-
-void GRSimpleVals::EvalObjCMessageExpr(ExplodedNodeSet<GRState>& Dst,
-                                       GRExprEngine& Eng,
-                                       GRStmtNodeBuilder<GRState>& Builder,
-                                       ObjCMessageExpr* ME,
-                                       ExplodedNode<GRState>* Pred) {
-  
-  
-  // The basic transfer function logic for message expressions does nothing.
-  // We just invalidate all arguments passed in by references.  
-  const GRState *St = Builder.GetState(Pred);
-  
-  for (ObjCMessageExpr::arg_iterator I = ME->arg_begin(), E = ME->arg_end();
-       I != E; ++I) {
-    
-    SVal V = St->getSVal(*I);
-    
-    if (isa<Loc>(V))
-      St = St->bindLoc(cast<Loc>(V), UnknownVal());
-  }
-  
-  Builder.MakeNode(Dst, ME, Pred, St);
-}