[cfe-users] Retrieve value from DeclExprRef

[Marcos Horro Varela via cfe-users]

Hello all,

 

Having a loop like this:

 

.

    |-DeclStmt 0x233fe40 <line:14:5, col:14>

    | `-VarDecl 0x233fdb8 <col:5, col:13> col:9 used I 'int' cinit

    |   `-IntegerLiteral 0x233fe20 <col:13> 'int' 0

.

    `-ForStmt 0x236b390 <line:29:5, line:33:5>

      |-DeclStmt 0x2340710 <line:29:10, col:19>

      | `-VarDecl 0x2340670 <col:10, col:18> col:14 used i 'int' cinit

      |   `-ImplicitCastExpr 0x23406f8 <col:18> 'int' <LValueToRValue>

      |     `-DeclRefExpr 0x23406d8 <col:18> 'int' lvalue Var 0x233fdb8 'I'
'int'

 

Which basically corresponds to:

 

Int I;

int I = 0;

.

for (i = I; ...)

 

I am trying to parse that loop such as:

 

const ASTContext *C = .

const DeclStmt *NameValInit = dyn_cast<DeclStmt>(ForLoop->getInit());

...

  if (NameValInit != nullptr) {

    clang::Expr::EvalResult R;

    V = dyn_cast<VarDecl>(NameValInit->getSingleDecl());

    if (V != nullptr) {

      if (V->getInit()->EvaluateAsInt(R, *C)) {

        return R.Val.getInt().getExtValue();

    }

.

 

I have checked this thread [1], which is very insightful. I guess that my
conceptual error lies in the "EvaluateAsInt", however, how can I retrieve
the value of the IntegerLiteral of the VarDecl referenced by the
DeclrRexExpr?

 

Thanks for your time.

 

Kind regards,

 

[1]
http://clang-developers.42468.n3.nabble.com/How-does-Clang-Staic-Analyzer-de
al-with-DeclRefExpr-tp4036387p4036398.html

 

--

H.

http://gac.udc.es/~horro

 

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