5.3 Debugging With dbx

Sun Studio provides a tightly integrated development environment for debugging applications written in Fortran, C, and C++.

The dbx program provides event management, process control, and data inspection. You can watch what is happening during program execution, and perform the following tasks:

• Fix one routine, then continue executing without recompiling the others

• Set watchpoints to stop or trace if a specified item changes

• Collect data for performance tuning

• Monitor variables, structures, and arrays

• Set breakpoints (set places to halt in the program) at lines or in functions

• Show values—once halted, show or modify variables, arrays, structures

• Step through a program, one source or assembly line at a time

• Trace program flow—show sequence of calls taken

• Invoke procedures in the program being debugged

• Step over or into function calls; step up and out of a function call

• Run, stop, and continue execution at the next line or at some other line

• Save and then replay all or part of a debugging run

• Examine the call stack, or move up and down the call stack

• Program scripts in the embedded Korn shell

• Follow programs as they fork(2) and exec(2)

To debug optimized programs, use the dbx fix command to recompile the routines you want to debug:

1. Compile the program with the appropriate -On optimization level.

2. Start the execution under dbx.

3. Use fix -g any.f without optimization on the routine you want to debug.

4. Use continue with that routine compiled.

Some optimizations will be inhibited by the presence of -g on the compilation command. See the dbx documentation for details.

For details, see the Sun Studio Debugging a Program With dbx manual, and the dbx(1) man pages.