[cfe-dev] "auto *IL = dyn_cast<IntegerLiteral>(e); " IL becomes NULL fails for negative integers.

Keane, Erich via cfe-dev cfe-dev at lists.llvm.org
Sat Nov 2 13:29:02 PDT 2019

The -100 is not the integer literal for 100 less than 0. It is the application of the unary operator '-' to the integer literal 100.

If you want to get the value, do the overload of isConstantExpr on Expr they takes a reference to APValue.

On Nov 2, 2019 1:16 PM, Devendran Mani via cfe-dev <cfe-dev at lists.llvm.org> wrote:

Hi All,

I need a support to find the below *IL  null pointer return for negative

integer numbers.

Checker code:

const Expr *e = vDecl->getInit();

auto *IL = dyn_cast<IntegerLiteral>(e);

if(IL !=NULL)


    double val = IL->getValue().signedRoundToDouble();

    cout << "val:" val;


test function:



    int val = 100;  (int val = -100;)

    printf("%d", val);


if the local variable is positive ex: int var 100;  then cout prints the

right value "100".

But if the local variable is negative ex: int var -100;  then IL becomes

NULL and cout is not executed.

Please help me root cause this issue.



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