Skip to main content
`Ctrl`+`K`

# PetscAttachDebuggerErrorHandler

Error handler that attaches a debugger to a running process when an error is detected. This routine is useful for examining variables, etc.

## Synopsis

    #include "petscsys.h"
    PetscErrorCode PetscAttachDebuggerErrorHandler(MPI_Comm comm, int line, const char *fun, const char *file, PetscErrorCode num, PetscErrorType p, const char *mess, void *ctx)

Not Collective, No Fortran Support

## Input Parameters

- comm - communicator over which error occurred

- line - the line number of the error (usually indicated by `__LINE__` in the calling routine)

- fun - the function name of the calling routine

- file - the file in which the error was detected (usually indicated by `__FILE__` in the calling routine)

- mess - an error text string, usually just printed to the screen

- num - the generic error number

- p - `PETSC_ERROR_INITIAL` if error just detected, otherwise `PETSC_ERROR_REPEAT`

- ctx - error handler context

## Notes

By default the GNU debugger, gdb, is used except on macOS where lldb is used. Alternatives are cuda-gdb, lldb, dbx and xxgdb,xldb (on IBM rs6000), xdb (on HP-UX).

Most users need not directly employ this routine and the other error handlers, but can instead use the simplified interface SETERR, which has the calling sequence

      SETERRQ(PETSC_COMM_SELF, number, p, message)

Use `PetscPushErrorHandler()` to set the desired error handler. The currently available PETSc error handlers are

        PetscTraceBackErrorHandler()
        PetscAttachDebuggerErrorHandler()
        PetscAbortErrorHandler()

or you may write your own.

## Developer Note

This routine calls abort instead of returning because if it returned then `MPI_Abort()` would get called which can generate an exception causing the debugger to be attached again in a cycle.

## See Also

`PetscSetDebuggerFromString()`, `PetscSetDebugger()`, `PetscSetDefaultDebugger()`, `PetscError()`, `PetscPushErrorHandler()`, `PetscPopErrorHandler()`, `PetscTraceBackErrorHandler()`, `PetscAbortErrorHandler()`, `PetscMPIAbortErrorHandler()`, `PetscEmacsClientErrorHandler()`, `PetscReturnErrorHandler()`, `PetscSetDebugTermainal()`

## Level

developer

## Location

src/sys/error/adebug.c

Index of all Sys routines
Table of Contents for all manual pages
Index of all manual pages