TotalView Users Guide - CI Wiki

Changing a Variable’s Data Type
� “Viewing Structures” on page 315
� “Viewing Unions” on page 315
� “Casting Using the Built-In Types” on page 315
You can change the way TotalView displays data in the Variable Window and
the Expression List Window by editing the data type. This is known as casting.
TotalView assigns types to all data types, and in most cases, they are
identical to their programming language counterparts.
When a C or C++ variable is displayed in TotalView, the data types are identical
to their C or C++ type representations, except for pointers to arrays.
TotalView uses a simpler syntax for pointers to arrays. (See “Viewing Pointers to
Arrays” on page 314.) Similarly, when Fortran is displayed in TotalView, the
types are identical to their Fortran type representations for most data types
including INTEGER, REAL, DOUBLE PRECISION, COMPLEX, LOGICAL, and
CHARACTER.
If the window contains a structure with a list of fields, you can edit the data
types of the listed fields.
When you edit a data type, TotalView changes how it displays the variable in the current
window. Other windows listing the variable do not change.
Displaying C and C++ Data Types
The syntax for displaying data is identical to C and C++ language cast syntax
for all data types except pointers to arrays. That is, you use C and C++
cast syntax for data types. For example, you can cast using types such as
int, char, unsigned, float, double, union, all named struct types, and so on.
In addition, TotalView has a built-in type called $string. Unless you tell it
otherwise, TotalView maps char arrays to this type. (For information on
wide characters, see “Viewing Wide Character Arrays ($wchar Data Types)” on
page 318.)
Read TotalView types from right to left. For example, $string*[20]* is a
pointer to an array of 20 pointers to $string.
The following table shows some common TotalView data types:
Data Type String Description
int Integer
int* Pointer to an integer
int[10] Array of 10 integers
$string Null-terminated character string
$string** Pointer to a pointer to a null-terminated character string
$string*[20]* Pointer to an array of 20 pointers to null-terminated strings
You can enter C and C++ Language cast syntax in the Type field.
Figure 200 on page 313 shows three different casts:
The two Variable Window cast the same data in the same way. In the top-left
window, a cast was used in the Expression field. In the other Variable Window,
312 Chapter 14: Examining and Changing Data