about summary refs log tree commit diff homepage
path: root/lib/Core/ExecutorUtil.cpp
blob: bd7c0711e039b739712839ad0a29d51b8bebb2a6 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
//===-- ExecutorUtil.cpp --------------------------------------------------===//
//
//                     The KLEE Symbolic Virtual Machine
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "Executor.h"

#include "Context.h"

#include "klee/Expr.h"
#include "klee/Interpreter.h"
#include "klee/Solver.h"

#include "klee/Config/Version.h"
#include "klee/Internal/Module/KModule.h"

#include "klee/util/GetElementPtrTypeIterator.h"

#include "llvm/IR/Function.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/DataLayout.h"

#include <cassert>

using namespace klee;
using namespace llvm;

namespace klee {

  ref<ConstantExpr> Executor::evalConstantExpr(const llvm::ConstantExpr *ce) {
    llvm::Type *type = ce->getType();

    ref<ConstantExpr> op1(0), op2(0), op3(0);
    int numOperands = ce->getNumOperands();

    if (numOperands > 0) op1 = evalConstant(ce->getOperand(0));
    if (numOperands > 1) op2 = evalConstant(ce->getOperand(1));
    if (numOperands > 2) op3 = evalConstant(ce->getOperand(2));

    switch (ce->getOpcode()) {
    default :
      ce->dump();
      llvm::errs() << "error: unknown ConstantExpr type\n"
                << "opcode: " << ce->getOpcode() << "\n";
      abort();

    case Instruction::Trunc: 
      return op1->Extract(0, getWidthForLLVMType(type));
    case Instruction::ZExt:  return op1->ZExt(getWidthForLLVMType(type));
    case Instruction::SExt:  return op1->SExt(getWidthForLLVMType(type));
    case Instruction::Add:   return op1->Add(op2);
    case Instruction::Sub:   return op1->Sub(op2);
    case Instruction::Mul:   return op1->Mul(op2);
    case Instruction::SDiv:  return op1->SDiv(op2);
    case Instruction::UDiv:  return op1->UDiv(op2);
    case Instruction::SRem:  return op1->SRem(op2);
    case Instruction::URem:  return op1->URem(op2);
    case Instruction::And:   return op1->And(op2);
    case Instruction::Or:    return op1->Or(op2);
    case Instruction::Xor:   return op1->Xor(op2);
    case Instruction::Shl:   return op1->Shl(op2);
    case Instruction::LShr:  return op1->LShr(op2);
    case Instruction::AShr:  return op1->AShr(op2);
    case Instruction::BitCast:  return op1;

    case Instruction::IntToPtr:
      return op1->ZExt(getWidthForLLVMType(type));

    case Instruction::PtrToInt:
      return op1->ZExt(getWidthForLLVMType(type));

    case Instruction::GetElementPtr: {
      ref<ConstantExpr> base = op1->ZExt(Context::get().getPointerWidth());

      for (gep_type_iterator ii = gep_type_begin(ce), ie = gep_type_end(ce);
           ii != ie; ++ii) {
        ref<ConstantExpr> addend = 
          ConstantExpr::alloc(0, Context::get().getPointerWidth());

        if (StructType *st = dyn_cast<StructType>(*ii)) {
          const StructLayout *sl = kmodule->targetData->getStructLayout(st);
          const ConstantInt *ci = cast<ConstantInt>(ii.getOperand());

          addend = ConstantExpr::alloc(sl->getElementOffset((unsigned)
                                                            ci->getZExtValue()),
                                       Context::get().getPointerWidth());
        } else {
          const SequentialType *set = cast<SequentialType>(*ii);
          ref<ConstantExpr> index = 
            evalConstant(cast<Constant>(ii.getOperand()));
          unsigned elementSize = 
            kmodule->targetData->getTypeStoreSize(set->getElementType());

          index = index->ZExt(Context::get().getPointerWidth());
          addend = index->Mul(ConstantExpr::alloc(elementSize, 
                                                  Context::get().getPointerWidth()));
        }

        base = base->Add(addend);
      }

      return base;
    }
      
    case Instruction::ICmp: {
      switch(ce->getPredicate()) {
      default: assert(0 && "unhandled ICmp predicate");
      case ICmpInst::ICMP_EQ:  return op1->Eq(op2);
      case ICmpInst::ICMP_NE:  return op1->Ne(op2);
      case ICmpInst::ICMP_UGT: return op1->Ugt(op2);
      case ICmpInst::ICMP_UGE: return op1->Uge(op2);
      case ICmpInst::ICMP_ULT: return op1->Ult(op2);
      case ICmpInst::ICMP_ULE: return op1->Ule(op2);
      case ICmpInst::ICMP_SGT: return op1->Sgt(op2);
      case ICmpInst::ICMP_SGE: return op1->Sge(op2);
      case ICmpInst::ICMP_SLT: return op1->Slt(op2);
      case ICmpInst::ICMP_SLE: return op1->Sle(op2);
      }
    }

    case Instruction::Select:
      return op1->isTrue() ? op2 : op3;

    case Instruction::FAdd:
    case Instruction::FSub:
    case Instruction::FMul:
    case Instruction::FDiv:
    case Instruction::FRem:
    case Instruction::FPTrunc:
    case Instruction::FPExt:
    case Instruction::UIToFP:
    case Instruction::SIToFP:
    case Instruction::FPToUI:
    case Instruction::FPToSI:
    case Instruction::FCmp:
      assert(0 && "floating point ConstantExprs unsupported");
    }
    llvm_unreachable("Unsupported expression in evalConstantExpr");
    return op1;
  }
}