SgAsmRiscOperation*
buildRiscOperation(SgAsmRiscOperation::RiscOperator op) {
SgAsmRiscOperation *retval = new SgAsmRiscOperation(op);
SgAsmExprListExp *operands = new SgAsmExprListExp;
operands->set_parent(retval);
retval->set_operands(operands);
return retval;
}
/* Returns true if the instruction modifies the instruction pointer (r15). */
static bool modifies_ip(SgAsmArmInstruction *insn)
{
switch (insn->get_kind()) {
/* Branch instructions */
case arm_b:
case arm_bl:
case arm_blx:
case arm_bx:
case arm_bxj:
return true;
/* Comparison instructions */
case arm_cmn:
case arm_cmp:
case arm_teq:
case arm_tst:
return false;
/* Load multiple registers instructions. Second argument is the set of registers to load. If the instruction
* pointer (r15) can be one of them. */
case arm_ldm:
case arm_ldmda:
case arm_ldmdb:
case arm_ldmia:
case arm_ldmib: {
const std::vector<SgAsmExpression*> &exprs = insn->get_operandList()->get_operands();
ROSE_ASSERT(exprs.size()>=2);
SgAsmExprListExp *elist = isSgAsmExprListExp(exprs[1]);
if (!elist) {
SgAsmUnaryArmSpecialRegisterList *rlist = isSgAsmUnaryArmSpecialRegisterList(exprs[1]);
ROSE_ASSERT(rlist);
elist = isSgAsmExprListExp(rlist->get_operand());
ROSE_ASSERT(elist);
}
for (size_t i=0; i<elist->get_expressions().size(); i++) {
SgAsmRegisterReferenceExpression *reg = isSgAsmRegisterReferenceExpression(elist->get_expressions()[i]);
ROSE_ASSERT(reg);
if (reg->get_descriptor().get_major()==arm_regclass_gpr && reg->get_descriptor().get_minor()==15) {
return true;
}
}
return false;
}
/* Interrupt-causing instructions */
case arm_bkpt:
case arm_swi:
case arm_undefined:
return true;
/* Other instructions modify the instruction pointer if it's the first (destination) argument. */
default: {
const std::vector<SgAsmExpression*> &exprs = insn->get_operandList()->get_operands();
if (exprs.size()>=1) {
SgAsmRegisterReferenceExpression *rre = isSgAsmRegisterReferenceExpression(exprs[0]);
if (rre &&
rre->get_descriptor().get_major()==arm_regclass_gpr && rre->get_descriptor().get_minor()==15) {
return true;
}
}
}
}
return false;
}
/* Helper function for unparseArmExpression(SgAsmExpression*)
*
* If this function is called for an EXPR node that cannot appear at the top of an ARM instruction operand tree then the node
* might create two strings: the primary expression return value and an additional string returned through the SUFFIX
* argument. What to do with the additional string depends on layers higher up in the call stack.
*
* The sign will be prepended to the result if EXPR is a value expression of some sort. */
static std::string unparseArmExpression(SgAsmExpression* expr, const AsmUnparser::LabelMap *labels,
ArmSignForExpressionUnparsing sign, std::string *suffix=NULL)
{
std::string result, extra;
if (!isSgAsmValueExpression(expr)) {
result += unparseArmSign(sign);
}
switch (expr->variantT()) {
case V_SgAsmBinaryMultiply:
ROSE_ASSERT (isSgAsmByteValueExpression(isSgAsmBinaryExpression(expr)->get_rhs()));
result = unparseArmExpression(isSgAsmBinaryExpression(expr)->get_lhs(), labels, arm_sign_none) + "*" +
StringUtility::numberToString(isSgAsmByteValueExpression(isSgAsmBinaryExpression(expr)->get_rhs()));
break;
case V_SgAsmBinaryLsl:
result = unparseArmExpression(isSgAsmBinaryExpression(expr)->get_lhs(), labels, arm_sign_none) + ", lsl " +
unparseArmExpression(isSgAsmBinaryExpression(expr)->get_rhs(), labels, arm_sign_none);
break;
case V_SgAsmBinaryLsr:
result = unparseArmExpression(isSgAsmBinaryExpression(expr)->get_lhs(), labels, arm_sign_none) + ", lsr " +
unparseArmExpression(isSgAsmBinaryExpression(expr)->get_rhs(), labels, arm_sign_none);
break;
case V_SgAsmBinaryAsr:
result = unparseArmExpression(isSgAsmBinaryExpression(expr)->get_lhs(), labels, arm_sign_none) + ", asr " +
unparseArmExpression(isSgAsmBinaryExpression(expr)->get_rhs(), labels, arm_sign_none);
break;
case V_SgAsmBinaryRor:
result = unparseArmExpression(isSgAsmBinaryExpression(expr)->get_lhs(), labels, arm_sign_none) + ", ror " +
unparseArmExpression(isSgAsmBinaryExpression(expr)->get_rhs(), labels, arm_sign_none);
break;
case V_SgAsmUnaryRrx:
result = unparseArmExpression(isSgAsmUnaryExpression(expr)->get_operand(), labels, arm_sign_none) + ", rrx";
break;
case V_SgAsmUnaryArmSpecialRegisterList:
result += unparseArmExpression(isSgAsmUnaryExpression(expr)->get_operand(), labels, arm_sign_none) + "^";
break;
case V_SgAsmExprListExp: {
SgAsmExprListExp* el = isSgAsmExprListExp(expr);
const std::vector<SgAsmExpression*>& exprs = el->get_expressions();
result += "{";
for (size_t i = 0; i < exprs.size(); ++i) {
if (i != 0) result += ", ";
result += unparseArmExpression(exprs[i], labels, arm_sign_none);
}
result += "}";
break;
}
case V_SgAsmBinaryAdd: {
/* This node cannot appear at the top of an ARM instruction operand tree */
SgAsmBinaryExpression *e = isSgAsmBinaryExpression(expr);
result += unparseArmExpression(e->get_lhs(), labels, arm_sign_none) + ", " +
unparseArmExpression(e->get_rhs(), labels, arm_sign_plus);
break;
}
case V_SgAsmBinarySubtract: {
/* This node cannot appear at the top of an ARM instruction operand tree */
SgAsmBinaryExpression *e = isSgAsmBinaryExpression(expr);
result += unparseArmExpression(e->get_lhs(), labels, arm_sign_none) + ", " +
unparseArmExpression(e->get_rhs(), labels, arm_sign_minus);
break;
}
case V_SgAsmBinaryAddPreupdate: {
/* This node cannot appear at the top of an ARM instruction operand tree */
SgAsmBinaryExpression *e = isSgAsmBinaryExpression(expr);
result += unparseArmExpression(e->get_lhs(), labels, arm_sign_none) + ", " +
unparseArmExpression(e->get_rhs(), labels, arm_sign_plus);
extra = "!";
break;
}
case V_SgAsmBinarySubtractPreupdate: {
/* This node cannot appear at the top of an ARM instruction operand tree */
SgAsmBinaryExpression *e = isSgAsmBinaryExpression(expr);
result += unparseArmExpression(e->get_lhs(), labels, arm_sign_none) + ", " +
unparseArmExpression(e->get_rhs(), labels, arm_sign_minus);
extra = "!";
break;
}
case V_SgAsmBinaryAddPostupdate: {
/* Two styles of syntax depending on whether this is at top-level or inside a memory reference expression. */
SgAsmBinaryExpression *e = isSgAsmBinaryExpression(expr);
if (suffix) {
result += unparseArmExpression(e->get_lhs(), labels, arm_sign_none);
extra = ", " + unparseArmExpression(e->get_rhs(), labels, arm_sign_plus);
} else {
/* Used by LDM* and STM* instructions outside memory reference expressions. RHS is unused. */
result = unparseArmExpression(e->get_lhs(), labels, arm_sign_none) + "!";
}
break;
}
case V_SgAsmBinarySubtractPostupdate: {
/* Two styles of syntax depending on whether this is at top-level or inside a memory reference expression. */
SgAsmBinaryExpression *e = isSgAsmBinaryExpression(expr);
if (suffix) {
result += unparseArmExpression(e->get_lhs(), labels, arm_sign_none);
extra = ", " + unparseArmExpression(e->get_rhs(), labels, arm_sign_minus);
} else {
/* Used by LDM* and STM* instructions outside memory reference expressions. RHS is unused. */
result += unparseArmExpression(e->get_lhs(), labels, arm_sign_none) + "!";
}
break;
}
case V_SgAsmMemoryReferenceExpression: {
SgAsmMemoryReferenceExpression* mr = isSgAsmMemoryReferenceExpression(expr);
SgAsmExpression* addr = mr->get_address();
switch (addr->variantT()) {
case V_SgAsmRegisterReferenceExpression:
case V_SgAsmBinaryAdd:
case V_SgAsmBinarySubtract:
case V_SgAsmBinaryAddPreupdate:
case V_SgAsmBinarySubtractPreupdate:
case V_SgAsmBinaryAddPostupdate:
case V_SgAsmBinarySubtractPostupdate:
break;
default: ROSE_ASSERT (!"Bad addressing mode");
}
std::string suffix;
result += "[" + unparseArmExpression(addr, labels, arm_sign_none, &suffix) + "]";
result += suffix;
break;
}
case V_SgAsmArmRegisterReferenceExpression:
result += unparseArmRegister(isSgAsmArmRegisterReferenceExpression(expr));
break;
case V_SgAsmByteValueExpression:
case V_SgAsmWordValueExpression:
case V_SgAsmDoubleWordValueExpression: {
SgAsmValueExpression *ve = isSgAsmValueExpression(expr);
assert(ve!=NULL);
uint64_t v = SageInterface::getAsmConstant(ve);
result += "#" + unparseArmSign(sign) + StringUtility::numberToString(v);
if (labels && v!=0) {
AsmUnparser::LabelMap::const_iterator li=labels->find(v);
if (li!=labels->end())
result += "<" + li->second + ">";
}
break;
}
default: {
std::cerr << "Unhandled expression kind " << expr->class_name() << std::endl;
ROSE_ASSERT (false);
}
}
/* The extra data should be passed back up the call stack so it can be inserted into the ultimate return string. We can't
* insert it here because the string can't be generated strictly left-to-right. If "suffix" is the null pointer then the
* caller isn't expecting a suffix and we'll have to just do our best -- the result will not be valid ARM assembly. */
if (extra.size()>0 && !suffix)
result = "\"" + result + "\" and \"" + extra + "\"";
if (suffix)
*suffix = extra;
if (expr->get_replacement() != "") {
result += " <" + expr->get_replacement() + ">";
}
return result;
}
