The IDB and Visual Studio debuggers let you debug mixed-language programs. Program flow of control across subprograms written in different languages is transparent.
The debuggers use debug information associated with the program to automatically identify the language of the current subprogram or code segment.
For example, if program execution is suspended in a subprogram in Fortran, the current language is seen as Fortran. If the debugger stops the program in a C function, the current language becomes C.
The IDB debugger sets the $lang debugger variable to the language of the current subprogram or code segment. By manually setting the $lang variable, you can force the IBD debugger to interpret expressions used in commands by the rules and semantics of a particular language. For example, you can check the current setting of $lang and change it as follows:
(idb) print $lang
"C++"
(idb) set $lang = "Fortran"
When the $lang variable is set to "Fortran", names are case-insensitive. To make names case-sensitive when the program was compiled with the -names as_is option, specify another language for the $lang variable, such as C, view the variable, then set the $lang variable to "Fortran."