backtrace / where

The backtrace commands prints a summary of how your program reached the current state.

Syntax

backtrace

Usage

The backtrace command prints a summary of your program's entire stack, one line per frame.

Each line in the output shows the frame number and function name.

bt and where are aliases for the backtrace command.

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