SVF::AbsExtAPI Class Reference

Handles external API calls and manages abstract states. More...

#include <AbsExtAPI.h>

Public Types
enum	ExtAPIType {   UNCLASSIFIED , MEMCPY , MEMSET , STRCPY ,   STRCAT }
	Enumeration of external API types. More...

Public Member Functions
	AbsExtAPI (Map< const ICFGNode *, AbstractState > &traces)
	Constructor for AbsExtAPI.
void	initExtFunMap ()
	Initializes the external function map.
std::string	strRead (AbstractState &as, const SVFVar *rhs)
	Reads a string from the abstract state.
void	handleExtAPI (const CallICFGNode *call)
	Handles an external API call.
void	handleStrcpy (const CallICFGNode *call)
	Handles the strcpy API call.
IntervalValue	getStrlen (AbstractState &as, const SVF::SVFVar *strValue)
	Calculates the length of a string.
void	handleStrcat (const SVF::CallICFGNode *call)
	Handles the strcat API call.
void	handleMemcpy (AbstractState &as, const SVF::SVFVar *dst, const SVF::SVFVar *src, IntervalValue len, u32_t start_idx)
	Handles the memcpy API call.
void	handleMemset (AbstractState &as, const SVFVar *dst, IntervalValue elem, IntervalValue len)
	Handles the memset API call.
IntervalValue	getRangeLimitFromType (const SVFType *type)
	Gets the range limit from a type.
AbstractState &	getAbsStateFromTrace (const ICFGNode *node)
	Retrieves the abstract state from the trace for a given ICFG node.

Protected Attributes
SVFIR *	svfir
	Pointer to the SVF intermediate representation.
ICFG *	icfg
	Pointer to the interprocedural control flow graph.
Map< const ICFGNode *, AbstractState > &	abstractTrace
	Map of ICFG nodes to abstract states.
Map< std::string, std::function< void(const CallICFGNode *)> >	func_map
	Map of function names to handlers.

Detailed Description

Handles external API calls and manages abstract states.

Definition at line 43 of file AbsExtAPI.h.

Member Enumeration Documentation

ExtAPIType

enum SVF::AbsExtAPI::ExtAPIType

Enumeration of external API types.

Enumerator
UNCLASSIFIED
MEMCPY
MEMSET
STRCPY
STRCAT

Definition at line 50 of file AbsExtAPI.h.

{ UNCLASSIFIED, MEMCPY, MEMSET, STRCPY, STRCAT };

Constructor & Destructor Documentation

AbsExtAPI()

AbsExtAPI::AbsExtAPI

(

Map< const ICFGNode *, AbstractState > &

traces

)

Constructor for AbsExtAPI.

Parameters

abstractTrace

Reference to a map of ICFG nodes to abstract states.

Definition at line 33 of file AbsExtAPI.cpp.

                                                               : abstractTrace(traces)
{
    svfir = PAG::getPAG();
    icfg = svfir->getICFG();
    initExtFunMap();
}

Member Function Documentation

getAbsStateFromTrace()

AbstractState & AbsExtAPI::getAbsStateFromTrace

(

const ICFGNode *

node

)

Retrieves the abstract state from the trace for a given ICFG node.

Parameters

node	Pointer to the ICFG node.

Returns

Reference to the abstract state.

Exceptions

Assertion

if no trace exists for the node.

Definition at line 377 of file AbsExtAPI.cpp.

{
    if (abstractTrace.count(node) == 0)
    {
        assert(0 && "No preAbsTrace for this node");
        abort();
    }
    else
    {
        return abstractTrace[node];
    }
}

getRangeLimitFromType()

IntervalValue AbsExtAPI::getRangeLimitFromType

(

const SVFType *

type

)

Gets the range limit from a type.

Parameters

type	Pointer to the SVF type.

Returns

The interval value representing the range limit.

This function, getRangeLimitFromType, calculates the lower and upper bounds of a numeric range for a given SVFType. It is used to determine the possible value range of integer types. If the type is an SVFIntegerType, it calculates the bounds based on the size and signedness of the type. The calculated bounds are returned as an IntervalValue representing the lower (lb) and upper (ub) limits of the range.

Parameters

type	The SVFType for which to calculate the value range.

Returns

An IntervalValue representing the lower and upper bounds of the range.

Definition at line 734 of file AbsExtAPI.cpp.

{
    if (const SVFIntegerType* intType = SVFUtil::dyn_cast<SVFIntegerType>(type))
    {
        u32_t bits = type->getByteSize() * 8;
        s64_t ub = 0;
        s64_t lb = 0;
        if (bits >= 32)
        {
            if (intType->isSigned())
            {
                ub = static_cast<s64_t>(std::numeric_limits<s32_t>::max());
                lb = static_cast<s64_t>(std::numeric_limits<s32_t>::min());
            }
            else
            {
                ub = static_cast<s64_t>(std::numeric_limits<u32_t>::max());
                lb = static_cast<s64_t>(std::numeric_limits<u32_t>::min());
            }
        }
        else if (bits == 16)
        {
            if (intType->isSigned())
            {
                ub = static_cast<s64_t>(std::numeric_limits<s16_t>::max());
                lb = static_cast<s64_t>(std::numeric_limits<s16_t>::min());
            }
            else
            {
                ub = static_cast<s64_t>(std::numeric_limits<u16_t>::max());
                lb = static_cast<s64_t>(std::numeric_limits<u16_t>::min());
            }
        }
        else if (bits == 8)
        {
            if (intType->isSigned())
            {
                ub = static_cast<s64_t>(std::numeric_limits<int8_t>::max());
                lb = static_cast<s64_t>(std::numeric_limits<int8_t>::min());
            }
            else
            {
                ub = static_cast<s64_t>(std::numeric_limits<uint8_t>::max());
                lb = static_cast<s64_t>(std::numeric_limits<uint8_t>::min());
            }
        }
        return IntervalValue(lb, ub);
    }
    else if (SVFUtil::isa<SVFOtherType>(type))
    {
        // handle other type like float double, set s32_t as the range
        s64_t ub = static_cast<s64_t>(std::numeric_limits<s32_t>::max());
        s64_t lb = static_cast<s64_t>(std::numeric_limits<s32_t>::min());
        return IntervalValue(lb, ub);
    }
    else
    {
        return IntervalValue::top();
        // other types, return top interval
    }
}

getStrlen()

IntervalValue AbsExtAPI::getStrlen	(	AbstractState &	as,
		const SVF::SVFVar *	strValue
	)

Calculates the length of a string.

Parameters

as	Reference to the abstract state.
strValue	Pointer to the SVF variable representing the string.

Returns

The interval value representing the string length.

Definition at line 502 of file AbsExtAPI.cpp.

{
    NodeID value_id = strValue->getId();
    u32_t dst_size = 0;
    for (const auto& addr : as[value_id].getAddrs())
    {
        NodeID objId = as.getIDFromAddr(addr);
        if (svfir->getBaseObject(objId)->isConstantByteSize())
        {
            dst_size = svfir->getBaseObject(objId)->getByteSizeOfObj();
        }
        else
        {
            const ICFGNode* icfgNode = svfir->getBaseObject(objId)->getICFGNode();
            for (const SVFStmt* stmt2: icfgNode->getSVFStmts())
            {
                if (const AddrStmt* addrStmt = SVFUtil::dyn_cast<AddrStmt>(stmt2))
                {
                    dst_size = as.getAllocaInstByteSize(addrStmt);
                }
            }
        }
    }
    u32_t len = 0;
    u32_t elemSize = 1;
    if (as.inVarToAddrsTable(value_id))
    {
        for (u32_t index = 0; index < dst_size; index++)
        {
            AbstractValue expr0 =
                as.getGepObjAddrs(value_id, IntervalValue(index));
            AbstractValue val;
            for (const auto &addr: expr0.getAddrs())
            {
                val.join_with(as.load(addr));
            }
            if (val.getInterval().is_numeral() && (char) val.getInterval().getIntNumeral() == '\0')
            {
                break;
            }
            ++len;
        }
        if (strValue->getType()->isArrayTy())
        {
            elemSize = SVFUtil::dyn_cast<SVFArrayType>(strValue->getType())->getTypeOfElement()->getByteSize();
        }
        else if (strValue->getType()->isPointerTy())
        {
            if (const SVFType* elemType = as.getPointeeElement(value_id))
            {
                if (elemType->isArrayTy())
                    elemSize = SVFUtil::dyn_cast<SVFArrayType>(elemType)->getTypeOfElement()->getByteSize();
                else
                    elemSize = elemType->getByteSize();
            }
            else
            {
                elemSize = 1;
            }
        }
        else
        {
            assert(false && "we cannot support this type");
        }
    }
    if (len == 0)
    {
        return IntervalValue((s64_t)0, (s64_t)Options::MaxFieldLimit());
    }
    else
    {
        return IntervalValue(len * elemSize);
    }
}

handleExtAPI()

void AbsExtAPI::handleExtAPI

(

const CallICFGNode *

call

)

Handles an external API call.

Parameters

call	Pointer to the call ICFG node.

Definition at line 420 of file AbsExtAPI.cpp.

{
    AbstractState& as = getAbsStateFromTrace(call);
    const FunObjVar *fun = call->getCalledFunction();
    assert(fun && "FunObjVar* is nullptr");
    ExtAPIType extType = UNCLASSIFIED;
    // get type of mem api
    for (const std::string &annotation: ExtAPI::getExtAPI()->getExtFuncAnnotations(fun))
    {
        if (annotation.find("MEMCPY") != std::string::npos)
            extType =  MEMCPY;
        if (annotation.find("MEMSET") != std::string::npos)
            extType =  MEMSET;
        if (annotation.find("STRCPY") != std::string::npos)
            extType = STRCPY;
        if (annotation.find("STRCAT") != std::string::npos)
            extType =  STRCAT;
    }
    if (extType == UNCLASSIFIED)
    {
        if (func_map.find(fun->getName()) != func_map.end())
        {
            func_map[fun->getName()](call);
        }
        else
        {
            if (const SVFVar* ret = call->getRetICFGNode()->getActualRet())
            {
                u32_t lhsId = ret->getId();
                if (as.inVarToAddrsTable(lhsId))
                {
 
                }
                else
                {
                    as[lhsId] = IntervalValue();
                }
            }
            return;
        }
    }
    // 1. memcpy functions like memcpy_chk, strncpy, annotate("MEMCPY"), annotate("BUF_CHECK:Arg0, Arg2"), annotate("BUF_CHECK:Arg1, Arg2")
    else if (extType == MEMCPY)
    {
        IntervalValue len = as[call->getArgument(2)->getId()].getInterval();
        svfir->getGNode(call->getArgument(0)->getId());
        handleMemcpy(as, call->getArgument(0), call->getArgument(1), len, 0);
    }
    else if (extType == MEMSET)
    {
        // memset dst is arg0, elem is arg1, size is arg2
        IntervalValue len = as[call->getArgument(2)->getId()].getInterval();
        IntervalValue elem = as[call->getArgument(1)->getId()].getInterval();
        handleMemset(as, call->getArgument(0), elem, len);
    }
    else if (extType == STRCPY)
    {
        handleStrcpy(call);
    }
    else if (extType == STRCAT)
    {
        handleStrcat(call);
    }
    else
    {
 
    }
    return;
}

handleMemcpy()

void AbsExtAPI::handleMemcpy	(	AbstractState &	as,
		const SVF::SVFVar *	dst,
		const SVF::SVFVar *	src,
		IntervalValue	len,
		u32_t	start_idx
	)

Handles the memcpy API call.

Parameters

as	Reference to the abstract state.
dst	Pointer to the destination SVF variable.
src	Pointer to the source SVF variable.
len	The interval value representing the length to copy.
start_idx	The starting index for copying.

Definition at line 613 of file AbsExtAPI.cpp.

{
    u32_t dstId = dst->getId(); // pts(dstId) = {objid}  objbar objtypeinfo->getType().
    u32_t srcId = src->getId();
    u32_t elemSize = 1;
    if (dst->getType()->isArrayTy())
    {
        elemSize = SVFUtil::dyn_cast<SVFArrayType>(dst->getType())->getTypeOfElement()->getByteSize();
    }
    // memcpy(i32*, i32*, 40)
    else if (dst->getType()->isPointerTy())
    {
        if (const SVFType* elemType = as.getPointeeElement(dstId))
        {
            if (elemType->isArrayTy())
                elemSize = SVFUtil::dyn_cast<SVFArrayType>(elemType)->getTypeOfElement()->getByteSize();
            else
                elemSize = elemType->getByteSize();
        }
        else
        {
            elemSize = 1;
        }
    }
    else
    {
        assert(false && "we cannot support this type");
    }
    u32_t size = std::min((u32_t)Options::MaxFieldLimit(), (u32_t) len.lb().getIntNumeral());
    u32_t range_val = size / elemSize;
    if (as.inVarToAddrsTable(srcId) && as.inVarToAddrsTable(dstId))
    {
        for (u32_t index = 0; index < range_val; index++)
        {
            // dead loop for string and break if there's a \0. If no \0, it will throw err.
            AbstractValue expr_src =
                as.getGepObjAddrs(srcId, IntervalValue(index));
            AbstractValue expr_dst =
                as.getGepObjAddrs(dstId, IntervalValue(index + start_idx));
            for (const auto &dst: expr_dst.getAddrs())
            {
                for (const auto &src: expr_src.getAddrs())
                {
                    u32_t objId = as.getIDFromAddr(src);
                    if (as.inAddrToValTable(objId))
                    {
                        as.store(dst, as.load(src));
                    }
                    else if (as.inAddrToAddrsTable(objId))
                    {
                        as.store(dst, as.load(src));
                    }
                }
            }
        }
    }
}

handleMemset()

void AbsExtAPI::handleMemset	(	AbstractState &	as,
		const SVFVar *	dst,
		IntervalValue	elem,
		IntervalValue	len
	)

Handles the memset API call.

Parameters

as	Reference to the abstract state.
dst	Pointer to the destination SVF variable.
elem	The interval value representing the element to set.
len	The interval value representing the length to set.

Definition at line 671 of file AbsExtAPI.cpp.

{
    u32_t dstId = dst->getId();
    u32_t size = std::min((u32_t)Options::MaxFieldLimit(), (u32_t) len.lb().getIntNumeral());
    u32_t elemSize = 1;
    if (dst->getType()->isArrayTy())
    {
        elemSize = SVFUtil::dyn_cast<SVFArrayType>(dst->getType())->getTypeOfElement()->getByteSize();
    }
    else if (dst->getType()->isPointerTy())
    {
        if (const SVFType* elemType = as.getPointeeElement(dstId))
        {
            elemSize = elemType->getByteSize();
        }
        else
        {
            elemSize = 1;
        }
    }
    else
    {
        assert(false && "we cannot support this type");
    }
 
    u32_t range_val = size / elemSize;
    for (u32_t index = 0; index < range_val; index++)
    {
        // dead loop for string and break if there's a \0. If no \0, it will throw err.
        if (as.inVarToAddrsTable(dstId))
        {
            AbstractValue lhs_gep = as.getGepObjAddrs(dstId, IntervalValue(index));
            for (const auto &addr: lhs_gep.getAddrs())
            {
                u32_t objId = as.getIDFromAddr(addr);
                if (as.inAddrToValTable(objId))
                {
                    AbstractValue tmp = as.load(addr);
                    tmp.join_with(elem);
                    as.store(addr, tmp);
                }
                else
                {
                    as.store(addr, elem);
                }
            }
        }
        else
            break;
    }
}

handleStrcat()

void AbsExtAPI::handleStrcat

(

const SVF::CallICFGNode *

call

)

Handles the strcat API call.

Parameters

call	Pointer to the call ICFG node.

Definition at line 578 of file AbsExtAPI.cpp.

{
    // __strcat_chk, strcat, __wcscat_chk, wcscat, __strncat_chk, strncat, __wcsncat_chk, wcsncat
    // to check it is  strcat group or strncat group
    AbstractState& as = getAbsStateFromTrace(call);
    const FunObjVar *fun = call->getCalledFunction();
    const std::vector<std::string> strcatGroup = {"__strcat_chk", "strcat", "__wcscat_chk", "wcscat"};
    const std::vector<std::string> strncatGroup = {"__strncat_chk", "strncat", "__wcsncat_chk", "wcsncat"};
    if (std::find(strcatGroup.begin(), strcatGroup.end(), fun->getName()) != strcatGroup.end())
    {
        const SVFVar* arg0Val = call->getArgument(0);
        const SVFVar* arg1Val = call->getArgument(1);
        IntervalValue strLen0 = getStrlen(as, arg0Val);
        IntervalValue strLen1 = getStrlen(as, arg1Val);
        IntervalValue totalLen = strLen0 + strLen1;
        handleMemcpy(as, arg0Val, arg1Val, strLen1, strLen0.lb().getIntNumeral());
        // do memcpy
    }
    else if (std::find(strncatGroup.begin(), strncatGroup.end(), fun->getName()) != strncatGroup.end())
    {
        const SVFVar* arg0Val = call->getArgument(0);
        const SVFVar* arg1Val = call->getArgument(1);
        const SVFVar* arg2Val = call->getArgument(2);
        IntervalValue arg2Num = as[arg2Val->getId()].getInterval();
        IntervalValue strLen0 = getStrlen(as, arg0Val);
        IntervalValue totalLen = strLen0 + arg2Num;
        handleMemcpy(as, arg0Val, arg1Val, arg2Num, strLen0.lb().getIntNumeral());
        // do memcpy
    }
    else
    {
        assert(false && "unknown strcat function, please add it to strcatGroup or strncatGroup");
    }
}

handleStrcpy()

void AbsExtAPI::handleStrcpy

(

const CallICFGNode *

call

)

Handles the strcpy API call.

Parameters

call	Pointer to the call ICFG node.

Definition at line 490 of file AbsExtAPI.cpp.

{
    // strcpy, __strcpy_chk, stpcpy , wcscpy, __wcscpy_chk
    // get the dst and src
    AbstractState& as = getAbsStateFromTrace(call);
    const SVFVar* arg0Val = call->getArgument(0);
    const SVFVar* arg1Val = call->getArgument(1);
    IntervalValue strLen = getStrlen(as, arg1Val);
    // no need to -1, since it has \0 as the last byte
    handleMemcpy(as, arg0Val, arg1Val, strLen, strLen.lb().getIntNumeral());
}

initExtFunMap()

void AbsExtAPI::initExtFunMap

(

)

Initializes the external function map.

Definition at line 40 of file AbsExtAPI.cpp.

{
#define SSE_FUNC_PROCESS(LLVM_NAME ,FUNC_NAME) \
        auto sse_##FUNC_NAME = [this](const CallICFGNode *callNode) { \
        /* run real ext function */            \
        AbstractState& as = getAbsStateFromTrace(callNode); \
        u32_t rhs_id = callNode->getArgument(0)->getId(); \
        if (!as.inVarToValTable(rhs_id)) return; \
        u32_t rhs = as[rhs_id].getInterval().lb().getIntNumeral(); \
        s32_t res = FUNC_NAME(rhs);            \
        u32_t lhsId = callNode->getRetICFGNode()->getActualRet()->getId();               \
        as[lhsId] = IntervalValue(res);           \
        return; \
    };                                                                         \
    func_map[#FUNC_NAME] = sse_##FUNC_NAME;
 
    SSE_FUNC_PROCESS(isalnum, isalnum);
    SSE_FUNC_PROCESS(isalpha, isalpha);
    SSE_FUNC_PROCESS(isblank, isblank);
    SSE_FUNC_PROCESS(iscntrl, iscntrl);
    SSE_FUNC_PROCESS(isdigit, isdigit);
    SSE_FUNC_PROCESS(isgraph, isgraph);
    SSE_FUNC_PROCESS(isprint, isprint);
    SSE_FUNC_PROCESS(ispunct, ispunct);
    SSE_FUNC_PROCESS(isspace, isspace);
    SSE_FUNC_PROCESS(isupper, isupper);
    SSE_FUNC_PROCESS(isxdigit, isxdigit);
    SSE_FUNC_PROCESS(llvm.sin.f64, sin);
    SSE_FUNC_PROCESS(llvm.cos.f64, cos);
    SSE_FUNC_PROCESS(llvm.tan.f64, tan);
    SSE_FUNC_PROCESS(llvm.log.f64, log);
    SSE_FUNC_PROCESS(sinh, sinh);
    SSE_FUNC_PROCESS(cosh, cosh);
    SSE_FUNC_PROCESS(tanh, tanh);
 
    auto sse_svf_assert = [this](const CallICFGNode* callNode)
    {
        AbstractInterpretation::getAEInstance().checkpoints.erase(callNode);
        u32_t arg0 = callNode->getArgument(0)->getId();
        AbstractState&as = getAbsStateFromTrace(callNode);
        if (as[arg0].getInterval().equals(IntervalValue(1, 1)))
        {
            SVFUtil::errs() << SVFUtil::sucMsg("The assertion is successfully verified!!\n");
        }
        else
        {
            SVFUtil::errs() << SVFUtil::errMsg("Assertion failure, this svf_assert cannot be verified!!\n") << callNode->toString() << "\n";
            assert(false);
        }
        return;
    };
    func_map["svf_assert"] = sse_svf_assert;
 
    auto svf_assert_eq = [this](const CallICFGNode* callNode)
    {
        u32_t arg0 = callNode->getArgument(0)->getId();
        u32_t arg1 = callNode->getArgument(1)->getId();
        AbstractState&as = getAbsStateFromTrace(callNode);
        if (as[arg0].getInterval().equals(as[arg1].getInterval()))
        {
            SVFUtil::errs() << SVFUtil::sucMsg("The assertion is successfully verified!!\n");
        }
        else
        {
            SVFUtil::errs() <<"svf_assert_eq Fail. " << callNode->toString() << "\n";
            assert(false);
        }
        return;
    };
    func_map["svf_assert_eq"] = svf_assert_eq;
 
    auto svf_print = [&](const CallICFGNode* callNode)
    {
        if (callNode->arg_size() < 2) return;
        AbstractState&as = getAbsStateFromTrace(callNode);
        u32_t num_id = callNode->getArgument(0)->getId();
        std::string text = strRead(as, callNode->getArgument(1));
        assert(as.inVarToValTable(num_id) && "print() should pass integer");
        IntervalValue itv = as[num_id].getInterval();
        std::cout << "Text: " << text <<", Value: " << callNode->getArgument(0)->toString()
                  << ", PrintVal: " << itv.toString() << ", Loc:" << callNode->getSourceLoc() << std::endl;
        return;
    };
    func_map["svf_print"] = svf_print;
 
    auto svf_set_value = [&](const CallICFGNode* callNode)
    {
        if (callNode->arg_size() < 2) return;
        AbstractState&as = getAbsStateFromTrace(callNode);
        AbstractValue& num = as[callNode->getArgument(0)->getId()];
        AbstractValue& lb = as[callNode->getArgument(1)->getId()];
        AbstractValue& ub = as[callNode->getArgument(2)->getId()];
        assert(lb.getInterval().is_numeral() && ub.getInterval().is_numeral());
        num.getInterval().set_to_top();
        num.getInterval().meet_with(IntervalValue(lb.getInterval().lb(), ub.getInterval().ub()));
        const ICFGNode* node = SVFUtil::cast<ValVar>(callNode->getArgument(0))->getICFGNode();
        for (const SVFStmt* stmt: node->getSVFStmts())
        {
            if (SVFUtil::isa<LoadStmt>(stmt))
            {
                const LoadStmt* load = SVFUtil::cast<LoadStmt>(stmt);
                NodeID rhsId = load->getRHSVarID();
                as.storeValue(rhsId, num);
            }
        }
        return;
    };
    func_map["set_value"] = svf_set_value;
 
    auto sse_scanf = [&](const CallICFGNode* callNode)
    {
        AbstractState& as = getAbsStateFromTrace(callNode);
        //scanf("%d", &data);
        if (callNode->arg_size() < 2) return;
 
        u32_t dst_id = callNode->getArgument(1)->getId();
        if (!as.inVarToAddrsTable(dst_id))
        {
            return;
        }
        else
        {
            AbstractValue Addrs = as[dst_id];
            for (auto vaddr: Addrs.getAddrs())
            {
                u32_t objId = as.getIDFromAddr(vaddr);
                AbstractValue range = getRangeLimitFromType(svfir->getGNode(objId)->getType());
                as.store(vaddr, range);
            }
        }
    };
    auto sse_fscanf = [&](const CallICFGNode* callNode)
    {
        //fscanf(stdin, "%d", &data);
        if (callNode->arg_size() < 3) return;
        AbstractState& as = getAbsStateFromTrace(callNode);
        u32_t dst_id = callNode->getArgument(2)->getId();
        if (!as.inVarToAddrsTable(dst_id))
        {
        }
        else
        {
            AbstractValue Addrs = as[dst_id];
            for (auto vaddr: Addrs.getAddrs())
            {
                u32_t objId = as.getIDFromAddr(vaddr);
                AbstractValue range = getRangeLimitFromType(svfir->getGNode(objId)->getType());
                as.store(vaddr, range);
            }
        }
    };
 
    func_map["__isoc99_fscanf"] = sse_fscanf;
    func_map["__isoc99_scanf"] = sse_scanf;
    func_map["__isoc99_vscanf"] = sse_scanf;
    func_map["fscanf"] = sse_fscanf;
    func_map["scanf"] = sse_scanf;
    func_map["sscanf"] = sse_scanf;
    func_map["__isoc99_sscanf"] = sse_scanf;
    func_map["vscanf"] = sse_scanf;
 
    auto sse_fread = [&](const CallICFGNode *callNode)
    {
        if (callNode->arg_size() < 3) return;
        AbstractState&as = getAbsStateFromTrace(callNode);
        u32_t block_count_id = callNode->getArgument(2)->getId();
        u32_t block_size_id = callNode->getArgument(1)->getId();
        IntervalValue block_count = as[block_count_id].getInterval();
        IntervalValue block_size = as[block_size_id].getInterval();
        IntervalValue block_byte = block_count * block_size;
    };
    func_map["fread"] = sse_fread;
 
    auto sse_sprintf = [&](const CallICFGNode *callNode)
    {
        // printf is difficult to predict since it has no byte size arguments
    };
 
    auto sse_snprintf = [&](const CallICFGNode *callNode)
    {
        if (callNode->arg_size() < 2) return;
        AbstractState&as = getAbsStateFromTrace(callNode);
        u32_t size_id = callNode->getArgument(1)->getId();
        u32_t dst_id = callNode->getArgument(0)->getId();
        // get elem size of arg2
        u32_t elemSize = 1;
        if (callNode->getArgument(2)->getType()->isArrayTy())
        {
            elemSize = SVFUtil::dyn_cast<SVFArrayType>(
                           callNode->getArgument(2)->getType())->getTypeOfElement()->getByteSize();
        }
        else if (callNode->getArgument(2)->getType()->isPointerTy())
        {
            elemSize = as.getPointeeElement(callNode->getArgument(2)->getId())->getByteSize();
        }
        else
        {
            return;
            // assert(false && "we cannot support this type");
        }
        IntervalValue size = as[size_id].getInterval() * IntervalValue(elemSize) - IntervalValue(1);
        if (!as.inVarToAddrsTable(dst_id))
        {
        }
    };
    func_map["__snprintf_chk"] = sse_snprintf;
    func_map["__vsprintf_chk"] = sse_sprintf;
    func_map["__sprintf_chk"] = sse_sprintf;
    func_map["snprintf"] = sse_snprintf;
    func_map["sprintf"] = sse_sprintf;
    func_map["vsprintf"] = sse_sprintf;
    func_map["vsnprintf"] = sse_snprintf;
    func_map["__vsnprintf_chk"] = sse_snprintf;
    func_map["swprintf"] = sse_snprintf;
    func_map["_snwprintf"] = sse_snprintf;
 
 
    auto sse_itoa = [&](const CallICFGNode* callNode)
    {
        // itoa(num, ch, 10);
        // num: int, ch: char*, 10 is decimal
        if (callNode->arg_size() < 3) return;
        AbstractState&as = getAbsStateFromTrace(callNode);
        u32_t num_id = callNode->getArgument(0)->getId();
 
        u32_t num = (u32_t) as[num_id].getInterval().getNumeral();
        std::string snum = std::to_string(num);
    };
    func_map["itoa"] = sse_itoa;
 
 
    auto sse_strlen = [&](const CallICFGNode *callNode)
    {
        // check the arg size
        if (callNode->arg_size() < 1) return;
        const SVFVar* strValue = callNode->getArgument(0);
        AbstractState& as = getAbsStateFromTrace(callNode);
        NodeID value_id = strValue->getId();
        u32_t lhsId = callNode->getRetICFGNode()->getActualRet()->getId();
        u32_t dst_size = 0;
        for (const auto& addr : as[value_id].getAddrs())
        {
            NodeID objId = as.getIDFromAddr(addr);
            if (svfir->getBaseObject(objId)->isConstantByteSize())
            {
                dst_size = svfir->getBaseObject(objId)->getByteSizeOfObj();
            }
            else
            {
                const ICFGNode* addrNode = svfir->getBaseObject(objId)->getICFGNode();
                for (const SVFStmt* stmt2: addrNode->getSVFStmts())
                {
                    if (const AddrStmt* addrStmt = SVFUtil::dyn_cast<AddrStmt>(stmt2))
                    {
                        dst_size = as.getAllocaInstByteSize(addrStmt);
                    }
                }
            }
        }
        u32_t len = 0;
        NodeID dstid = strValue->getId();
        if (as.inVarToAddrsTable(dstid))
        {
            for (u32_t index = 0; index < dst_size; index++)
            {
                AbstractValue expr0 =
                    as.getGepObjAddrs(dstid, IntervalValue(index));
                AbstractValue val;
                for (const auto &addr: expr0.getAddrs())
                {
                    val.join_with(as.load(addr));
                }
                if (val.getInterval().is_numeral() && (char) val.getInterval().getIntNumeral() == '\0')
                {
                    break;
                }
                ++len;
            }
        }
        if (len == 0)
        {
            as[lhsId] = IntervalValue((s64_t)0, (s64_t)Options::MaxFieldLimit());
        }
        else
        {
            as[lhsId] = IntervalValue(len);
        }
    };
    func_map["strlen"] = sse_strlen;
    func_map["wcslen"] = sse_strlen;
 
    auto sse_recv = [&](const CallICFGNode *callNode)
    {
        // recv(sockfd, buf, len, flags);
        if (callNode->arg_size() < 4) return;
        AbstractState&as = getAbsStateFromTrace(callNode);
        u32_t len_id = callNode->getArgument(2)->getId();
        IntervalValue len = as[len_id].getInterval() - IntervalValue(1);
        u32_t lhsId = callNode->getRetICFGNode()->getActualRet()->getId();
        as[lhsId] = len;
    };
    func_map["recv"] = sse_recv;
    func_map["__recv"] = sse_recv;
 
    auto sse_free = [&](const CallICFGNode *callNode)
    {
        if (callNode->arg_size() < 1) return;
        AbstractState& as = getAbsStateFromTrace(callNode);
        const u32_t freePtr = callNode->getArgument(0)->getId();
        for (auto addr: as[freePtr].getAddrs())
        {
            if (AbstractState::isInvalidMem(addr))
            {
                // Detected a double free — the address has already been freed.
                // No action is taken at this point.
            }
            else
            {
                as.addToFreedAddrs(addr);
            }
        }
    };
    // Add all free-related functions to func_map
    std::vector<std::string> freeFunctions =
    {
        "VOS_MemFree", "cfree", "free", "free_all_mem", "freeaddrinfo",
        "gcry_mpi_release", "gcry_sexp_release", "globfree", "nhfree",
        "obstack_free", "safe_cfree", "safe_free", "safefree", "safexfree",
        "sm_free", "vim_free", "xfree", "SSL_CTX_free", "SSL_free", "XFree"
    };
 
    for (const auto& name : freeFunctions)
    {
        func_map[name] = sse_free;
    }
};

strRead()

std::string AbsExtAPI::strRead	(	AbstractState &	as,
		const SVFVar *	rhs
	)

Reads a string from the abstract state.

Parameters

as	Reference to the abstract state.
rhs	Pointer to the SVF variable representing the string.

Returns

The string value.

Definition at line 390 of file AbsExtAPI.cpp.

{
    // sse read string nodeID->string
    std::string str0;
 
    for (u32_t index = 0; index < Options::MaxFieldLimit(); index++)
    {
        // dead loop for string and break if there's a \0. If no \0, it will throw err.
        if (!as.inVarToAddrsTable(rhs->getId())) continue;
        AbstractValue expr0 =
            as.getGepObjAddrs(rhs->getId(), IntervalValue(index));
 
        AbstractValue val;
        for (const auto &addr: expr0.getAddrs())
        {
            val.join_with(as.load(addr));
        }
        if (!val.getInterval().is_numeral())
        {
            break;
        }
        if ((char) val.getInterval().getIntNumeral() == '\0')
        {
            break;
        }
        str0.push_back((char) val.getInterval().getIntNumeral());
    }
    return str0;
}

Member Data Documentation

abstractTrace

Map<const ICFGNode*, AbstractState>& SVF::AbsExtAPI::abstractTrace

protected

Map of ICFG nodes to abstract states.

Definition at line 134 of file AbsExtAPI.h.

func_map

Map<std::string, std::function<void(const CallICFGNode*)> > SVF::AbsExtAPI::func_map

protected

Map of function names to handlers.

Definition at line 135 of file AbsExtAPI.h.

icfg

ICFG* SVF::AbsExtAPI::icfg

protected

Pointer to the interprocedural control flow graph.

Definition at line 133 of file AbsExtAPI.h.

svfir

SVFIR* SVF::AbsExtAPI::svfir

protected

Pointer to the SVF intermediate representation.

Definition at line 132 of file AbsExtAPI.h.

---

The documentation for this class was generated from the following files:

• /home/runner/work/SVF/SVF/svf/include/AE/Svfexe/AbsExtAPI.h
• /home/runner/work/SVF/SVF/svf/lib/AE/Svfexe/AbsExtAPI.cpp