frame

The frame command selects and prints a stack frame.

Syntax

frame [ frame-num ]

frame-num is the stack frame number of the frame that you wish to select.

Usage

The frame command allows you to move from one stack frame to another, and to print the stack frame that you select. Each stack frame is associated with one call to one function within the currently executing program. Without an argument, the current stack frame is printed.

See stack frames for a brief discussion of frames.

Example

MAIN
    CALL func1()
END MAIN

FUNCTION func1() RETURNS ()
    DEFINE x INT, s STRING
    CALL func2() RETURNING x, s
END FUNCTION

FUNCTION func2() RETURNS (INT,STRING)
    RETURN 999, "xxxxxx"
END FUNCTION

$ fglcomp -M prog.4gl && fglrun -d prog.42m

(fgldb) break func2
Breakpoint 1 at 0x00000000: file prog.4gl, line 11.

(fgldb) run
Breakpoint 1, func2() at prog.4gl:11
   8     END FUNCTION
   9
   10    FUNCTION func2() RETURNS (INT,STRING)
-> 11        RETURN 999, "xxxxxx"
   12    END FUNCTION
   13

(fgldb) backtrace
#0 func2() at prog.4gl:11
#1 func1() at prog.4gl:7
#2 main() at prog.4gl:2

(fgldb) frame 1
#1 func1() at prog.4gl:7
   4
   5     FUNCTION func1() RETURNS ()
   6         DEFINE x INT, s STRING
-> 7         CALL func2() RETURNING x, s
   8     END FUNCTION
   9
   10    FUNCTION func2() RETURNS (INT,STRING)

(fgldb) frame 2
#2 main() at prog.4gl:2
   1     MAIN
-> 2         CALL func1()
   3     END MAIN
   4
   5     FUNCTION func1() RETURNS ()