Sun Studio 12: Debugging a Program With dbx

Using Runtime Checking in Batch Mode

The bcheck utility is a convenient batch interface to the runtime checking feature of dbx. It runs a program under dbx and by default, places the runtime checking error output in the default file program.errs.

The bcheck utility can perform memory leak checking, memory access checking, memory use checking, or all three. Its default action is to perform only leak checking. See the bcheck(1) man page for more details on its use.

Note –

Before running the bcheck utility on a system running the 64-bit Linux OS, you must set the _DBX_EXEC_32 environment variable.

bcheck Syntax

The syntax for bcheck is:

bcheck [-V] [-access | -all | -leaks | -memuse] [-o logfile] [-q]
[-s script] program [args]

Use the -o logfile option to specify a different name for the logfile. Use the -s script option before executing the program to read in the dbx commands contained in the file script. The script file typically contains commands like suppress and dbxenv to tailor the error output of the bcheck utility.

The -q option makes the bcheck utility completely quiet, returning with the same status as the program. This option is useful when you want to use the bcheck utility in scripts or makefiles.

bcheck Examples

To perform only leak checking on hello, type:

bcheck hello

To perform only access checking on mach with the argument 5, type:

bcheck -access mach 5

To perform memory use checking on cc quietly and exit with normal exit status, type:

bcheck -memuse -q cc -c prog.c

The program does not stop when runtime errors are detected in batch mode. All error output is redirected to your error log file logfile. The program stops when breakpoints are encountered or if the program is interrupted.

In batch mode, the complete stack backtrace is generated and redirected to the error log file. The number of stack frames can be controlled using the dbx environment variable stack_max_size.

If the file logfile already exists, bcheck erases the contents of that file before it redirects the batch output to it.

Enabling Batch Mode Directly From dbx

You can also enable a batch-like mode directly from dbx by setting the dbx environment variables rtc_auto_continue and rtc_error_log_file_name (see Setting dbx Environment Variables).

If rtc_auto_continue is set to on, runtime checking continues to find errors and keeps running automatically. It redirects errors to the file named by the dbx environment variable rtc_error_log_file_name. (See Setting dbx Environment Variables.) The default log file name is /tmp/dbx.errlog.uniqueid. To redirect all errors to the terminal, set the rtc_error_log_file_name environment variable to /dev/tty.

By default, rtc_auto_continue is set to off.