[cfe-dev] [Clang Static Code Analyzer]: Need information about Callee.

[Prashant Purohit]

Hi all,

I need to know information about callee when a function is called using array of function pointer.

I have written following code to get the Callee name using Checker:
class SampleEvalCall : public Checker<eval::Call> {
public:
  bool evalCall(const CallExpr *CE, CheckerContext &C) const {
    /** Output function name */
   llvm::errs() << C.getCalleeName(CE) << " is called\n";
   return false;
  }
};

I am getting names for normal function calls but when a function is called using array function pointer, checker does not give any output.

Following is the sample program using function pointer where checker fails to give callee name.

///////////////////////////////////////////////////////////////////////////////////////////////////
#define ARRAY_SIZE1 2
#define ARRAY_SIZE2 2
#define IDX_00 0
#define TRUE 0
#define FALSE 1

typedef unsigned char U1;
typedef unsigned short U2;

typedef struct
{
    U2 mask;
    U1 a;
    U2 (*func_ptr)(void);
} STRUCT_1;

typedef struct
{
    U2 b;
    const STRUCT_1 * struct_ptr;
} STRUCT_2;

static U1 ram_var = 1;
static U1 index_2 = 0;

U2 func1(void)
{
    return((U2)ram_var);
}

U2 func2(void)
{
    ram_var = 3;
    return((U2)ram_var);
}

static const STRUCT_1 array1[ARRAY_SIZE1] =
{
    {
        (U2)TRUE,
        (U1)FALSE,
        &func1
    },
                {
        (U2)TRUE,
        (U1)FALSE,
        &func2
    }
};

static const STRUCT_2 array2[ARRAY_SIZE2] =
{
    {
        (U2)FALSE,
        &array1[IDX_00]
    }
};

int main()
{
    U2 index_1 = 1;
    U2 ret;
    /* I need to get list of function called by below function pointer. */
    ret = (*((array2[0].struct_ptr[0].func_ptr)))() &
              array2[index_2].struct_ptr[index_1].mask;

    return (int)ret;
}
///////////////////////////////////////////////////////////////////////////////////////////////////

I understand that checker cannot get the callee name as it will be known at runtime but I need to get
the list of all functions that might be called in main function in above program. I need to get 'func1' and 'func2' function name in above
example from checker as a potential callee, one of which will definitely get called at run time.

Kindly suggest me a way to get this list.

Thanks,
Prashant S. Purohit
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