void
RiscOperators::writeRegister(RegisterDescriptor reg, const BaseSemantics::SValuePtr &value) {
SymbolicExpr::Ptr expr = SValue::promote(value)->get_expression();
if (expr->isLeafNode()) {
std::string comment = commentForVariable(reg, "write");
State::promote(currentState())->varComment(expr->isLeafNode()->toString(), comment);
}
Super::writeRegister(reg, value);
}
BaseSemantics::SValuePtr
RiscOperators::readRegister(RegisterDescriptor reg, const BaseSemantics::SValuePtr &dflt) {
SValuePtr retval = SValue::promote(Super::readRegister(reg, dflt));
SymbolicExpr::Ptr expr = retval->get_expression();
if (expr->isLeafNode()) {
std::string comment = commentForVariable(reg, "read");
State::promote(currentState())->varComment(expr->isLeafNode()->toString(), comment);
}
return retval;
}
SymbolicExpr::VisitAction preVisit(const SymbolicExpr::Ptr &node) {
if (!seen.insert(getRawPointer(node)).second)
return SymbolicExpr::TRUNCATE; // already processed this subexpression
if (SymbolicExpr::LeafPtr leaf = node->isLeafNode()) {
if (leaf->isVariable()) {
if (defns->find(leaf->nameId()) == defns->end()) {
defns->insert(leaf->nameId());
yices_type bvtype = yices_mk_bitvector_type(self->context, leaf->nBits());
ASSERT_not_null(bvtype);
std::string name = "v" + StringUtility::numberToString(leaf->nameId());
yices_var_decl vdecl __attribute__((unused)) = yices_mk_var_decl(self->context, name.c_str(), bvtype);
ASSERT_not_null(vdecl);
}
} else if (leaf->isMemory()) {
if (defns->find(leaf->nameId()) == defns->end()) {
defns->insert(leaf->nameId());
yices_type domain = yices_mk_bitvector_type(self->context, leaf->domainWidth());
yices_type range = yices_mk_bitvector_type(self->context, leaf->nBits());
yices_type ftype = yices_mk_function_type(self->context, &domain, 1, range);
ASSERT_not_null(ftype);
std::string name = "m" + StringUtility::numberToString(leaf->nameId());
yices_var_decl vdecl __attribute__((unused)) = yices_mk_var_decl(self->context, name.c_str(), ftype);
ASSERT_not_null(vdecl);
}
}
}
return SymbolicExpr::CONTINUE;
}
/** Output a decimal number. */
void
YicesSolver::out_number(std::ostream &o, const SymbolicExpr::Ptr &tn)
{
SymbolicExpr::LeafPtr ln = tn->isLeafNode();
ASSERT_require(ln && ln->isNumber());
o <<ln->toInt();
}
/** Read memory.
*
* If multi-path is enabled, then return a new memory expression that describes the process of reading a value from the
* specified address; otherwise, actually read the value and return it. In any case, record some information about the
* address that's being read if we've never seen it before. */
BaseSemantics::SValuePtr
RiscOperators::readMemory(RegisterDescriptor segreg, const BaseSemantics::SValuePtr &addr,
const BaseSemantics::SValuePtr &dflt_, const BaseSemantics::SValuePtr &cond) {
BaseSemantics::SValuePtr dflt = dflt_;
const size_t nBytes = dflt->get_width() / 8;
if (cond->is_number() && !cond->get_number())
return dflt_;
// If we know the address and that memory exists, then read the memory to obtain the default value.
uint8_t buf[8];
if (addr->is_number() && nBytes < sizeof(buf) &&
nBytes == partitioner_->memoryMap()->at(addr->get_number()).limit(nBytes).read(buf).size()) {
// FIXME[Robb P. Matzke 2015-05-25]: assuming little endian
uint64_t value = 0;
for (size_t i=0; i<nBytes; ++i)
value |= (uint64_t)buf[i] << (8*i);
dflt = number_(dflt->get_width(), value);
}
// Read from the symbolic state, and update the state with the default from real memory if known.
BaseSemantics::SValuePtr retval = Super::readMemory(segreg, addr, dflt, cond);
if (!currentInstruction())
return retval; // not called from dispatcher on behalf of an instruction
// Save a description of the variable
SymbolicExpr::Ptr valExpr = SValue::promote(retval)->get_expression();
if (valExpr->isLeafNode() && valExpr->isLeafNode()->isVariable()) {
std::string comment = commentForVariable(addr, "read");
State::promote(currentState())->varComment(valExpr->isLeafNode()->toString(), comment);
}
// Save a description for its addresses
for (size_t i=0; i<nBytes; ++i) {
SValuePtr va = SValue::promote(add(addr, number_(addr->get_width(), i)));
if (va->get_expression()->isLeafNode()) {
std::string comment = commentForVariable(addr, "read", i, nBytes);
State::promote(currentState())->varComment(va->get_expression()->isLeafNode()->toString(), comment);
}
}
return retval;
}
/** Write value to memory.
*
* If multi-path is enabled, then return a new memory expression that updates memory with a new address/value pair;
* otherwise update the memory directly. In any case, record some information about the address that was written if we've
* never seen it before. */
void
RiscOperators::writeMemory(RegisterDescriptor segreg, const BaseSemantics::SValuePtr &addr,
const BaseSemantics::SValuePtr &value, const BaseSemantics::SValuePtr &cond) {
if (cond->is_number() && !cond->get_number())
return;
Super::writeMemory(segreg, addr, value, cond);
// Save a description of the variable
SymbolicExpr::Ptr valExpr = SValue::promote(value)->get_expression();
if (valExpr->isLeafNode() && valExpr->isLeafNode()->isVariable()) {
std::string comment = commentForVariable(addr, "write");
State::promote(currentState())->varComment(valExpr->isLeafNode()->toString(), comment);
}
// Save a description for its addresses
size_t nBytes = value->get_width() / 8;
for (size_t i=0; i<nBytes; ++i) {
SValuePtr va = SValue::promote(add(addr, number_(addr->get_width(), i)));
if (va->get_expression()->isLeafNode()) {
std::string comment = commentForVariable(addr, "read", i, nBytes);
State::promote(currentState())->varComment(va->get_expression()->isLeafNode()->toString(), comment);
}
}
}
std::string
RiscOperators::commentForVariable(const BaseSemantics::SValuePtr &addr, const std::string &accessMode, size_t byteNumber,
size_t nBytes) const {
std::string varComment = "first " + accessMode + " at ";
if (pathInsnIndex_ != (size_t)(-1))
varComment += "path position #" + StringUtility::numberToString(pathInsnIndex_) + ", ";
varComment += "instruction " + unparseInstructionWithAddress(currentInstruction());
// Sometimes we can save useful information about the address.
if (nBytes != 1) {
SymbolicExpr::Ptr addrExpr = SValue::promote(addr)->get_expression();
if (SymbolicExpr::LeafPtr addrLeaf = addrExpr->isLeafNode()) {
if (addrLeaf->isNumber()) {
varComment += "\n";
if (nBytes > 1) {
varComment += StringUtility::numberToString(byteNumber) + " of " +
StringUtility::numberToString(nBytes) + " bytes starting ";
}
varComment += "at address " + addrLeaf->toString();
}
} else if (SymbolicExpr::InteriorPtr addrINode = addrExpr->isInteriorNode()) {
if (addrINode->getOperator() == SymbolicExpr::OP_ADD && addrINode->nChildren() == 2 &&
addrINode->child(0)->isLeafNode() && addrINode->child(0)->isLeafNode()->isVariable() &&
addrINode->child(1)->isLeafNode() && addrINode->child(1)->isLeafNode()->isNumber()) {
SymbolicExpr::LeafPtr base = addrINode->child(0)->isLeafNode();
SymbolicExpr::LeafPtr offset = addrINode->child(1)->isLeafNode();
varComment += "\n";
if (nBytes > 1) {
varComment += StringUtility::numberToString(byteNumber) + " of " +
StringUtility::numberToString(nBytes) + " bytes starting ";
}
varComment += "at address ";
if (base->comment().empty()) {
varComment = base->toString();
} else {
varComment += base->comment();
}
Sawyer::Container::BitVector tmp = offset->bits();
if (tmp.get(tmp.size()-1)) {
varComment += " - 0x" + tmp.negate().toHex();
} else {
varComment += " + 0x" + tmp.toHex();
}
}
}
}
return varComment;
}
SymbolicExpr::VisitAction preVisit(const SymbolicExpr::Ptr &node) {
if (!seen.insert(getRawPointer(node)).second)
return SymbolicExpr::TRUNCATE; // already processed this subexpression
if (SymbolicExpr::LeafPtr leaf = node->isLeafNode()) {
if ((leaf->isVariable() || leaf->isMemory()) && !leaf->comment().empty()) {
if (!commented) {
o <<"\n"
<<";;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;\n"
<<"; Variable comments\n"
<<";;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;\n";
commented = true;
}
o <<"\n; " <<leaf->toString() <<": "
<<StringUtility::prefixLines(leaf->comment(), "; ", false) <<"\n";
}
}
return SymbolicExpr::CONTINUE;
}
SymbolicExpr::VisitAction preVisit(const SymbolicExpr::Ptr &node) {
if (!seen.insert(getRawPointer(node)).second)
return SymbolicExpr::TRUNCATE; // already processed this subexpression
if (SymbolicExpr::LeafPtr leaf = node->isLeafNode()) {
if (leaf->isVariable()) {
if (defns->find(leaf->nameId())==defns->end()) {
defns->insert(leaf->nameId());
o <<"\n";
if (!leaf->comment().empty())
o <<StringUtility::prefixLines(leaf->comment(), "; ") <<"\n";
o <<"(define v" <<leaf->nameId() <<"::" <<get_typename(leaf) <<")\n";
}
} else if (leaf->isMemory()) {
if (defns->find(leaf->nameId())==defns->end()) {
defns->insert(leaf->nameId());
o <<"\n";
if (!leaf->comment().empty())
o <<StringUtility::prefixLines(leaf->comment(), "; ") <<"\n";
o <<"(define m" <<leaf->nameId() <<"::" <<get_typename(leaf) <<")\n";
}
}
}
return SymbolicExpr::CONTINUE;
}
/** Output for one expression. */
void
YicesSolver::out_expr(std::ostream &o, const SymbolicExpr::Ptr &tn)
{
SymbolicExpr::LeafPtr ln = tn->isLeafNode();
SymbolicExpr::InteriorPtr in = tn->isInteriorNode();
std::string subExprName;
if (termNames.getOptional(tn).assignTo(subExprName)) {
o <<subExprName;
} else if (ln) {
if (ln->isNumber()) {
if (ln->nBits() <= 64) {
o <<"(mk-bv " <<ln->nBits() <<" " <<ln->toInt() <<")";
} else {
o <<"0b" <<ln->bits().toBinary();
}
} else if (ln->isMemory()) {
o <<"m" <<ln->nameId();
} else {
ASSERT_require(ln->isVariable());
o <<"v" <<ln->nameId();
}
} else {
ASSERT_not_null(in);
switch (in->getOperator()) {
case SymbolicExpr::OP_ADD: out_la(o, "bv-add", in, false); break;
case SymbolicExpr::OP_AND: out_la(o, "and", in, true); break;
case SymbolicExpr::OP_ASR: out_asr(o, in); break;
case SymbolicExpr::OP_BV_AND: out_la(o, "bv-and", in, true); break;
case SymbolicExpr::OP_BV_OR: out_la(o, "bv-or", in, false); break;
case SymbolicExpr::OP_BV_XOR: out_la(o, "bv-xor", in, false); break;
case SymbolicExpr::OP_EQ: out_binary(o, "=", in); break;
case SymbolicExpr::OP_CONCAT: out_la(o, "bv-concat", in); break;
case SymbolicExpr::OP_EXTRACT: out_extract(o, in); break;
case SymbolicExpr::OP_INVERT: out_unary(o, "bv-not", in); break;
case SymbolicExpr::OP_ITE: out_ite(o, in); break;
case SymbolicExpr::OP_LSSB: throw Exception("OP_LSSB not implemented");
case SymbolicExpr::OP_MSSB: throw Exception("OP_MSSB not implemented");
case SymbolicExpr::OP_NE: out_binary(o, "/=", in); break;
case SymbolicExpr::OP_NEGATE: out_unary(o, "bv-neg", in); break;
case SymbolicExpr::OP_NOOP: o<<"0b1"; break;
case SymbolicExpr::OP_OR: out_la(o, "or", in, false); break;
case SymbolicExpr::OP_READ: out_read(o, in); break;
case SymbolicExpr::OP_ROL: throw Exception("OP_ROL not implemented");
case SymbolicExpr::OP_ROR: throw Exception("OP_ROR not implemented");
case SymbolicExpr::OP_SDIV: throw Exception("OP_SDIV not implemented");
case SymbolicExpr::OP_SET: out_set(o, in); break;
case SymbolicExpr::OP_SEXTEND: out_sext(o, in); break;
case SymbolicExpr::OP_SLT: out_binary(o, "bv-slt", in); break;
case SymbolicExpr::OP_SLE: out_binary(o, "bv-sle", in); break;
case SymbolicExpr::OP_SHL0: out_shift(o, "bv-shift-left", in, false); break;
case SymbolicExpr::OP_SHL1: out_shift(o, "bv-shift-left", in, true); break;
case SymbolicExpr::OP_SHR0: out_shift(o, "bv-shift-right", in, false); break;
case SymbolicExpr::OP_SHR1: out_shift(o, "bv-shift-right", in, true); break;
case SymbolicExpr::OP_SGE: out_binary(o, "bv-sge", in); break;
case SymbolicExpr::OP_SGT: out_binary(o, "bv-sgt", in); break;
case SymbolicExpr::OP_SMOD: throw Exception("OP_SMOD not implemented");
case SymbolicExpr::OP_SMUL: out_mult(o, in); break;
case SymbolicExpr::OP_UDIV: throw Exception("OP_UDIV not implemented");
case SymbolicExpr::OP_UEXTEND: out_uext(o, in); break;
case SymbolicExpr::OP_UGE: out_binary(o, "bv-ge", in); break;
case SymbolicExpr::OP_UGT: out_binary(o, "bv-gt", in); break;
case SymbolicExpr::OP_ULE: out_binary(o, "bv-le", in); break;
case SymbolicExpr::OP_ULT: out_binary(o, "bv-lt", in); break;
case SymbolicExpr::OP_UMOD: throw Exception("OP_UMOD not implemented");
case SymbolicExpr::OP_UMUL: out_mult(o, in); break;
case SymbolicExpr::OP_WRITE: out_write(o, in); break;
case SymbolicExpr::OP_ZEROP: out_zerop(o, in); break;
}
}
}
