Viewing Fortran Data Types in the Debugger

The following general suggestions apply to different types of Fortran data:

• For scalar (nonarray) data, use the data tips (leave pointer on a variable name) feature or use the Local Variables window.
• For single-dimension array data, derived-type data, record structure data, and COMPLEX data, use the Local Variables window or the Watch window.
• For multidimension array data, use the Local Variables window, the Watch window, or (Professional and Enterprise Editions) the Array Viewer.
• For common blocks in a DLL, move (drag) the name of the common block to the Watch window. You will be able to view the common block fields like any other structure.

For information on using Data Tips, the Local Variables window, or a Watch window, see Debugging the Squares Example Program.

For information on using the Array Viewer in the debugger, see Using the Array Viewer in the Debugger.

The following sections apply to using the Watch window:

• Specifying Array Sections
• Specifying Module Variables
• Specifying Format Specifiers

To display the Watch window:

1. In the View menu, point at (or click) Debug Windows
2. In the submenu, click Watch

Specifying Array Sections

You can specify array sections in a watch window. For example, consider an array declared as:

  integer foo(10)

You can specify the following statement in a watch window to see the 2nd, 5th, and 8th elements:

  foo(2:10:3)

When working with character arrays, this syntax may be combined with a substring specification. Consider the following array declaration:

  character*8 chr_arr(10)

You can specify the following statement in a watch window to display the substring made up of character 3 through 8 of array elements 2 through 5:

  chr_arr(2:5)(3:8)

This support is available for arrays of any type, including array pointers, assumed-shape, allocatable, and assumed-size arrays.

Any valid integer expression can be used when specifying lower bound, upper bound, or stride. If the lower bound is omitted, the array lower bound is used. If the upper bound is omitted, the array upper bound is used. For example, consider the following declaration:

  integer foo(10)

To display:

• Elements 1 through 8, specify foo(:8)
• Elements 5 through 10, specify foo(5:)
• All 10 elements, specify foo(:)

Specifying Module Variables

To view a module variable in the Watch window, specify the module name, followed by "::", followed by the variable name.

For example, to watch variable "bar" of module "foo", specify the following expression:

  foo::bar

Specifying Format Specifiers

You can use format specifiers in Watch windows to display variables in different data formats.

For example, given a REAL variable 'foo' in a program, it is now possible to see 'foo' in different floating point notation (by typing "foo,f" "foo,g" or "foo,e" in a Watch window) or as an integer (""foo,i" or "foo,d"), a hexadecimal value ("foo,x"), an an octal value ("foo,o"), and so on.

You can change the display format of variables in the Watch window using the formatting symbols in the following table:

To use a formatting symbol, type the variable name, followed by a comma and the appropriate symbol. For example, if var has a value of 0x0065, and you want to see the value in character form, type var,c in the Name column on the tab of the Watch window. When you press ENTER, the character-format value appears:

  var,c = 'e'

You can use the formatting symbols shown in the following table to format the contents of memory locations:

With the memory location formatting symbols, you can type any value or expression that evaluates to a location.

A formatting character can follow an expression also:

  rep+1,x
  alps[0],mb
  xloc,g
  count,d

---

Note: You can apply formatting symbols to structures, arrays, pointers, and objects as unexpanded variables only. If you expand the variable, the specified formatting affects all members. You cannot apply formatting symbols to individual members.

---