SVF Global not found

[LeoneChen]

I use https://github.com/SVF-tools/SVF-example to process two *.ll files (in attachment), but get "SVF Global not found"

Inside SVFModule* svfModule = LLVMModuleSet::buildSVFModule(moduleNameVec);

llvmVal may be a global replacement of val,

SVF/svf-llvm/lib/LLVMModule.cpp

Lines 1221 to 1223 in 0eae653

	const Value* llvmVal = LLVMUtil::getGlobalRep(val);
	assert(SVFUtil::isa<GlobalValue>(llvmVal) && "not a GlobalValue?");
	glob->setDefGlobalForMultipleModule(getSVFGlobalValue(SVFUtil::cast<GlobalValue>(llvmVal)));

and then in getSVFGlobalValue, LLVMConst2SVFConst may not able to find g in itself since LLVMConst2SVFConst only updated on non-replacement value, then reports "SVF Global not found!"

SVF/svf-llvm/include/SVF-LLVM/LLVMModule.h

Line 236 in 0eae653

assert(it!=LLVMConst2SVFConst.end() && "SVF Global not found!");

capsule_manager-43d688dc37a73ece.zip

[yuleisui]

Any idea to fix this?

[LeoneChen]

I don't have a global view of svf project right now, if it's feasible to update the replacement value or other similar solutions while adding per element to LLVMConst2SVFConst?

[yuleisui]

What is the replacement value? Shall we use this value for global or use the previous one. We will need to map multiple global values to the one actually used?

[LeoneChen]

Sorry I mean global replacement usually used in optimization for global value.
https://chatgpt.com/share/2d4cc8ce-9ce4-4b87-afd6-7fcffb4347ad

I'm not sure how to fix it

[LeoneChen]

Any idea about this statement const Value* llvmVal = LLVMUtil::getGlobalRep(val);

[yuleisui]

This is used to get the representation global if we have multiple global symbols referring to the same global variable, so that we could use a unique global to represent all.

looks like we didn’t set the rep global first.

[LeoneChen]

Ok I got it, let me test if updating LLVMConst2SVFConst using the representation global works

[yuleisui]

Thanks

[LeoneChen]

I've added a patch to fix the issue I was having, but I don't think this fix the root cause, i.e. it does not fully examine the use of global representation in the whole project.

The reason why I add V = LLVMUtil::getGlobalRep(V); is that val is converted to global representation in collectObj to perform insert on symInfo->objSymMap

SVF/svf-llvm/lib/SymbolTableBuilder.cpp

Lines 318 to 330 in 0eae653

	void SymbolTableBuilder::collectObj(const Value* val)
	{
	val = LLVMUtil::getGlobalRep(val);
	SymbolTableInfo::ValueToIDMapTy::iterator iter = symInfo->objSymMap.find(
	LLVMModuleSet::getLLVMModuleSet()->getSVFValue(val));
	if (iter == symInfo->objSymMap.end())
	{
	SVFValue* svfVal = LLVMModuleSet::getLLVMModuleSet()->getSVFValue(val);
	// if the object pointed by the pointer is a constant data (e.g., i32 0) or a global constant object (e.g. string)
	// then we treat them as one ConstantObj
	if (isConstantObjSym(val) && !symInfo->getModelConstants())
	{
	symInfo->objSymMap.insert(std::make_pair(svfVal, symInfo->constantSymID()));

[yuleisui]

Could you make a pull request?

[LeoneChen]

PR #1484
Ok, but I'm not sure that it fixes all of these problems