TestStand pointeur en valeur retournée

Question

Bonjour,
je dois utiliser une fonction dll standard, qui renvoie une chaine de caratctères : Prototype C : char  * version();
Vu qu'il n'y a pas de possibilité de récupérer un pointeur dans une valeur retournée, comment peut-on récupérer la texte dans un appel de fonction TestStand ?
Merci pour votre aide.
Jean-Marie.
JMCe
Solved!
Go to Solution.

Answer 1

TestStand does not currently support string return values because TestStand doesn't know how to deallocate the memory associated with the string. If you must call a function in a standard DLL that returns a string, you have a couple of options. Each of them requires you to write your own DLL.
1. Write a wrapper function in a DLL that calls the string function. Your wrapper DLL must link to the standard DLL. For example,
void VersionWrapper(char returnValue[], int bufferLength)
    char *versionString = version();
    if (versionString != NULL)
        strncpy(returnValue, versionString, bufferLength);
    // You must deallocate versionString here if necessary.
2. Call the string function in TestStand manually specifying the return value as an integer. Write a conversion function in a DLL that converts the integer to a char pointer. For example,
void ConvertIntToString(int returnValueFromTestStand, char returnValue[], int bufferLength)
    const char *returnValueString = (const char *)returnValueFromTestStand;
    if (returnValueString != NULL)
        strncpy(returnValue, returnValueString , bufferLength);
    // You must deallocate returnValueString here if necessary.
Note: If the string function in the standard DLL is exported with a C++ decorated name, the function will not appear in the function list in TestStand and you cannot use option 2.