[llvm-dev] DebugInfo, Metadata usage

[DES via llvm-dev]

Hello LLVM Community,
I'm working on some analyzer\checker and want to implement checker for
variables.

In that case, I want to retrieve some information about types of
variables or identify that the variable is either string or not.
As an example, for strings which can be char or string type I came up
with a solution to find it out via isString or isCString methods. But
for strings whose type is wchar my approach is not working. Cause,
internally in IR wchar string is an array of integers.

I looked up some information about how to get types of variables that
were got from the source level in IR level. (I've been reading some info
in LLVM Blog about metadata, in llvm docs about SourceLevel Debugging
with LLVM + StripSymbols.cpp, Metadata.cpp, DebugInfo.cpp)
I found that I can get it from DebugInfo or Metadata.
But my little research was not successful.
 
my code excerpt:

 DebugInfoFinder DIFinder;
    DIFinder.processModule(*M);
    llvm::outs() << "Count of global Variables in Module : " <<
DIFinder.global_variable_count() << "\n";
 
    for(DIGlobalVariableExpression *DIGVExpr : DIFinder.global_variables())
    {
        if(DIGlobalVariable *DIGV = DIGVExpr->getVariable())
        {
            llvm::outs() << "DIGV DisplayName : " <<
DIGV->getDisplayName() << "\n";
        }
    }
 
    for(DIType *DIT : DIFinder.types())
    {
        if(DIBasicType* DIBT = dyn_cast<DIBasicType>(DIT))
        {
            llvm::outs() << "DIBasicType in Module : " << DIT->getName()
<< "\n";
            StringRef Encoding =
dwarf::AttributeEncodingString(DIBT->getEncoding());
            if(!Encoding.empty())
            {
                llvm::outs() << "Encoding : " << Encoding.str() << "\n";
            }
        }
    }
 
    llvm::outs() << "\n\nPrint All Strings Declarations: \n";
    for(GlobalVariable& GV : M->globals())
    {
        if(!GV.hasInitializer()) continue;
 
        if(ConstantDataSequential *CDS =
dyn_cast<ConstantDataSequential>(GV.getInitializer()))
        {
            llvm::outs() << "GVName: " << GV.getName() << "\n";
            llvm::outs() << "\tRawDataValues : " <<
CDS->getRawDataValues().str() << "\n";  // here I see my wchar string
 

            if(CDS->isString() || CDS->isCString())  // but these checks
are not appropriate for checking strings of wchar's type
            {
                llvm::outs() << "\tCString&&Std::String : " <<
CDS->getAsString().str() << "\n";
            }
        }
    }

What way can I get  DIBasicType for ConstantDataSequential?
Literally, I want to know is there any way to get the relationship
between constant, globals and related debuginfo, metadata information?

I would appreciate it for any help.
In advance, thank you very much.

-- 
----------------------
the best regards!
0x0859549A