Actual source code: err.c

  1: /*
  2:       Code that allows one to set the error handlers
  3:       Portions of this code are under:
  4:       Copyright (c) 2022 Advanced Micro Devices, Inc. All rights reserved.
  5: */
  6: #include <petsc/private/petscimpl.h>
  7: #include <petscviewer.h>

  9: typedef struct _EH *EH;
 10: struct _EH {
 11:   PetscErrorCode (*handler)(MPI_Comm, int, const char *, const char *, PetscErrorCode, PetscErrorType, const char *, void *);
 12:   void *ctx;
 13:   EH    previous;
 14: };

 16: /* This is here to allow the traceback error handler (or potentially other error handlers)
 17:    to certify that PETSCABORT is being called on all MPI processes, and that it should be possible to call
 18:    MPI_Finalize() and exit().  This should only be used when `PetscCIEnabledPortabeErrorOutput == PETSC_TRUE`
 19:    to allow testing of error messages.  Do not rely on this for clean exit in production. */
 20: PetscBool petscabortmpifinalize = PETSC_FALSE;

 22: static EH eh = NULL;

 24: /*@C
 25:   PetscEmacsClientErrorHandler - Error handler that uses the emacsclient program to
 26:   load the file where the error occurred. Then calls the "previous" error handler.

 28:   Not Collective

 30:   Input Parameters:
 31: + comm - communicator over which error occurred
 32: . line - the line number of the error (usually indicated by `__LINE__` in the calling routine)
 33: . file - the file in which the error was detected (usually indicated by `__FILE__` in the calling routine)
 34: . fun  - the function name of the calling routine
 35: . mess - an error text string, usually just printed to the screen
 36: . n    - the generic error number
 37: . p    - `PETSC_ERROR_INITIAL` indicates this is the first time the error handler is being called while `PETSC_ERROR_REPEAT` indicates it was previously called
 38: - ctx  - error handler context

 40:   Options Database Key:
 41: . -on_error_emacs <machinename> - will contact machinename to open the Emacs client there

 43:   Level: developer

 45:   Note:
 46:   You must put (server-start) in your .emacs file for the emacsclient software to work

 48:   Developer Note:
 49:   Since this is an error handler it cannot call `PetscCall()`; thus we just return if an error is detected.
 50:   But some of the functions it calls do perform error checking that may not be appropriate in a error handler call.

 52: .seealso: `PetscError()`, `PetscPushErrorHandler()`, `PetscPopErrorHandler()`, `PetscAttachDebuggerErrorHandler()`,
 53:           `PetscAbortErrorHandler()`, `PetscMPIAbortErrorHandler()`, `PetscTraceBackErrorHandler()`, `PetscReturnErrorHandler()`,
 54:           `PetscErrorType`, `PETSC_ERROR_INITIAL`, `PETSC_ERROR_REPEAT`, `PetscErrorCode`
 55:  @*/
 56: PetscErrorCode PetscEmacsClientErrorHandler(MPI_Comm comm, int line, const char *fun, const char *file, PetscErrorCode n, PetscErrorType p, const char *mess, void *ctx)
 57: {
 58:   PetscErrorCode ierr;
 59:   char           command[PETSC_MAX_PATH_LEN];
 60:   const char    *pdir;
 61:   FILE          *fp;

 63:   ierr = PetscGetPetscDir(&pdir);
 64:   if (ierr) return ierr;
 65:   ierr = PetscSNPrintf(command, PETSC_STATIC_ARRAY_LENGTH(command), "cd %s; emacsclient --no-wait +%d %s\n", pdir, line, file);
 66:   if (ierr) return ierr;
 67: #if defined(PETSC_HAVE_POPEN)
 68:   ierr = PetscPOpen(MPI_COMM_WORLD, (char *)ctx, command, "r", &fp);
 69:   if (ierr) return ierr;
 70:   ierr = PetscPClose(MPI_COMM_WORLD, fp);
 71:   if (ierr) return ierr;
 72: #else
 73:   SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP_SYS, "Cannot run external programs on this machine");
 74: #endif
 75:   ierr = PetscPopErrorHandler();
 76:   if (ierr) return ierr; /* remove this handler from the stack of handlers */
 77:   if (!eh) {
 78:     ierr = PetscTraceBackErrorHandler(comm, line, fun, file, n, p, mess, NULL);
 79:     if (ierr) return ierr;
 80:   } else {
 81:     ierr = (*eh->handler)(comm, line, fun, file, n, p, mess, eh->ctx);
 82:     if (ierr) return ierr;
 83:   }
 84:   return PETSC_SUCCESS;
 85: }

 87: /*@C
 88:   PetscPushErrorHandler - Sets a routine to be called on detection of errors.

 90:   Not Collective

 92:   Input Parameters:
 93: + handler - error handler routine
 94: - ctx     - optional handler context that contains information needed by the handler (for
 95:             example file pointers for error messages etc.)

 97:   Calling sequence of `handler`:
 98: + comm - communicator over which error occurred
 99: . line - the line number of the error (usually indicated by `__LINE__` in the calling routine)
100: . file - the file in which the error was detected (usually indicated by `__FILE__` in the calling routine)
101: . fun  - the function name of the calling routine
102: . n    - the generic error number (see list defined in include/petscerror.h)
103: . p    - `PETSC_ERROR_INITIAL` if error just detected, otherwise `PETSC_ERROR_REPEAT`
104: . mess - an error text string, usually just printed to the screen
105: - ctx  - the error handler context

107:   Options Database Keys:
108: + -on_error_attach_debugger <noxterm,lldb or gdb> - starts up the debugger if an error occurs
109: - -on_error_abort                                 - aborts the program if an error occurs

111:   Level: intermediate

113:   Note:
114:   The currently available PETSc error handlers include `PetscTraceBackErrorHandler()`,
115:   `PetscAttachDebuggerErrorHandler()`, `PetscAbortErrorHandler()`, `PetscMPIAbortErrorHandler()`, and `PetscReturnErrorHandler()`.

117:   Fortran Note:
118:   You can only push a single error handler from Fortran before popping it.

120: .seealso: `PetscPopErrorHandler()`, `PetscAttachDebuggerErrorHandler()`, `PetscAbortErrorHandler()`, `PetscTraceBackErrorHandler()`, `PetscPushSignalHandler()`,
121:           `PetscErrorType`, `PETSC_ERROR_INITIAL`, `PETSC_ERROR_REPEAT`, `PetscErrorCode`
122: @*/
123: PetscErrorCode PetscPushErrorHandler(PetscErrorCode (*handler)(MPI_Comm comm, int line, const char *fun, const char *file, PetscErrorCode n, PetscErrorType p, const char *mess, void *ctx), void *ctx)
124: {
125:   EH neweh;

127:   PetscFunctionBegin;
128:   PetscCall(PetscNew(&neweh));
129:   if (eh) neweh->previous = eh;
130:   else neweh->previous = NULL;
131:   neweh->handler = handler;
132:   neweh->ctx     = ctx;
133:   eh             = neweh;
134:   PetscFunctionReturn(PETSC_SUCCESS);
135: }

137: /*@
138:   PetscPopErrorHandler - Removes the latest error handler that was
139:   pushed with `PetscPushErrorHandler()`.

141:   Not Collective

143:   Level: intermediate

145: .seealso: `PetscPushErrorHandler()`
146: @*/
147: PetscErrorCode PetscPopErrorHandler(void)
148: {
149:   EH tmp;

151:   PetscFunctionBegin;
152:   if (!eh) PetscFunctionReturn(PETSC_SUCCESS);
153:   tmp = eh;
154:   eh  = eh->previous;
155:   PetscCall(PetscFree(tmp));
156:   PetscFunctionReturn(PETSC_SUCCESS);
157: }

159: /*@C
160:   PetscReturnErrorHandler - Error handler that causes a return without printing an error message.

162:   Not Collective

164:   Input Parameters:
165: + comm - communicator over which error occurred
166: . line - the line number of the error (usually indicated by `__LINE__` in the calling routine)
167: . fun  - the function name
168: . file - the file in which the error was detected (usually indicated by `__FILE__` in the calling routine)
169: . mess - an error text string, usually just printed to the screen
170: . n    - the generic error number
171: . p    - `PETSC_ERROR_INITIAL` indicates this is the first time the error handler is being called while `PETSC_ERROR_REPEAT` indicates it was previously called
172: - ctx  - error handler context

174:   Level: developer

176:   Notes:
177:   Users do not directly employ this routine

179:   Use `PetscPushErrorHandler()` to set the desired error handler.  The
180:   currently available PETSc error handlers include `PetscTraceBackErrorHandler()`,
181:   `PetscAttachDebuggerErrorHandler()`, and `PetscAbortErrorHandler()`.

183: .seealso: `PetscPushErrorHandler()`, `PetscPopErrorHandler()`, `PetscError()`, `PetscAbortErrorHandler()`, `PetscMPIAbortErrorHandler()`, `PetscTraceBackErrorHandler()`,
184:           `PetscAttachDebuggerErrorHandler()`, `PetscEmacsClientErrorHandler()`,
185:           `PetscErrorType`, `PETSC_ERROR_INITIAL`, `PETSC_ERROR_REPEAT`, `PetscErrorCode`
186:  @*/
187: PetscErrorCode PetscReturnErrorHandler(MPI_Comm comm, int line, const char *fun, const char *file, PetscErrorCode n, PetscErrorType p, const char *mess, void *ctx)
188: {
189:   (void)comm;
190:   (void)line;
191:   (void)fun;
192:   (void)file;
193:   (void)p;
194:   (void)mess;
195:   (void)ctx;
196:   return n;
197: }

199: static char PetscErrorBaseMessage[1024];
200: /*
201:        The numerical values for these are defined in include/petscerror.h; any changes
202:    there must also be made here
203: */
204: static const char *PetscErrorStrings[] = {
205:   /*55 */ "Out of memory",
206:   "No support for this operation for this object type",
207:   "No support for this operation on this system",
208:   /*58 */ "Operation done in wrong order",
209:   /*59 */ "Signal received",
210:   /*60 */ "Nonconforming object sizes",
211:   "Argument aliasing not permitted",
212:   "Invalid argument",
213:   /*63 */ "Argument out of range",
214:   "Corrupt argument: https://petsc.org/release/faq/#valgrind",
215:   "Unable to open file",
216:   "Read from file failed",
217:   "Write to file failed",
218:   "Invalid pointer",
219:   /*69 */ "Arguments must have same type",
220:   /*70 */ "Attempt to use a pointer that does not point to a valid accessible location",
221:   /*71 */ "Zero pivot in LU factorization: https://petsc.org/release/faq/#zeropivot",
222:   /*72 */ "Floating point exception",
223:   /*73 */ "Object is in wrong state",
224:   "Corrupted Petsc object",
225:   "Arguments are incompatible",
226:   "Error in external library",
227:   /*77 */ "Petsc has generated inconsistent data",
228:   "Memory corruption: https://petsc.org/release/faq/#valgrind",
229:   "Unexpected data in file",
230:   /*80 */ "Arguments must have same communicators",
231:   /*81 */ "Zero pivot in Cholesky factorization: https://petsc.org/release/faq/#zeropivot",
232:   "",
233:   "",
234:   "Overflow in integer operation: https://petsc.org/release/faq/#64-bit-indices",
235:   /*85 */ "Null argument, when expecting valid pointer",
236:   /*86 */ "Unknown type. Check for miss-spelling or missing package: https://petsc.org/release/install/install/#external-packages",
237:   /*87 */ "MPI library at runtime is not compatible with MPI used at compile time",
238:   /*88 */ "Error in system call",
239:   /*89 */ "Object Type not set: https://petsc.org/release/faq/#object-type-not-set",
240:   /*90 */ "",
241:   /*   */ "",
242:   /*92 */ "See https://petsc.org/release/overview/linear_solve_table/ for possible LU and Cholesky solvers",
243:   /*93 */ "You cannot overwrite this option since that will conflict with other previously set options",
244:   /*94 */ "Example/application run with number of MPI ranks it does not support",
245:   /*95 */ "Missing or incorrect user input",
246:   /*96 */ "GPU resources unavailable",
247:   /*97 */ "GPU error",
248:   /*98 */ "General MPI error",
249:   /*99 */ "PetscError() incorrectly returned an error code of 0"};

251: /*@C
252:   PetscErrorMessage - Returns the text string associated with a PETSc error code.

254:   Not Collective

256:   Input Parameter:
257: . errnum - the error code

259:   Output Parameters:
260: + text     - the error message (`NULL` if not desired)
261: - specific - the specific error message that was set with `SETERRQ()` or
262:              `PetscError()`. (`NULL` if not desired)

264:   Level: developer

266: .seealso: `PetscErrorCode`, `PetscPushErrorHandler()`, `PetscAttachDebuggerErrorHandler()`,
267: `PetscError()`, `SETERRQ()`, `PetscCall()` `PetscAbortErrorHandler()`,
268: `PetscTraceBackErrorHandler()`
269: @*/
270: PetscErrorCode PetscErrorMessage(PetscErrorCode errnum, const char *text[], char **specific)
271: {
272:   PetscFunctionBegin;
273:   if (text) {
274:     if (errnum > PETSC_ERR_MIN_VALUE && errnum < PETSC_ERR_MAX_VALUE) {
275:       size_t len;

277:       *text = PetscErrorStrings[errnum - PETSC_ERR_MIN_VALUE - 1];
278:       PetscCall(PetscStrlen(*text, &len));
279:       if (!len) *text = NULL;
280:     } else if (errnum == PETSC_ERR_BOOLEAN_MACRO_FAILURE) {
281:       /* this "error code" arises from failures in boolean macros, where the || operator is
282:          used to short-circuit the macro call in case of error. This has the side effect of
283:          "returning" either 0 (PETSC_SUCCESS) or 1 (PETSC_ERR_UNKNONWN):

285:          #define PETSC_FOO(x) ((PetscErrorCode)(PetscBar(x) || PetscBaz(x)))

287:          If PetscBar() fails (returns nonzero) PetscBaz() is not executed but the result of
288:          this expression is boolean false, hence PETSC_ERR_UNNOWN
289:        */
290:       *text = "Error occurred in boolean shortcuit in macro";
291:     } else {
292:       *text = NULL;
293:     }
294:   }
295:   if (specific) *specific = PetscErrorBaseMessage;
296:   PetscFunctionReturn(PETSC_SUCCESS);
297: }

299: #if defined(PETSC_CLANGUAGE_CXX)
300:   /* C++ exceptions are formally not allowed to propagate through extern "C" code. In practice, far too much software
301:  * would be broken if implementations did not handle it it some common cases. However, keep in mind
302:  *
303:  *   Rule 62. Don't allow exceptions to propagate across module boundaries
304:  *
305:  * in "C++ Coding Standards" by Sutter and Alexandrescu. (This accounts for part of the ongoing C++ binary interface
306:  * instability.) Having PETSc raise errors as C++ exceptions was probably misguided and should eventually be removed.
307:  *
308:  * Here is the problem: You have a C++ function call a PETSc function, and you would like to maintain the error message
309:  * and stack information from the PETSc error. You could make everyone write exactly this code in their C++, but that
310:  * seems crazy to me.
311:  */
312:   #include <sstream>
313:   #include <stdexcept>
314: static void PetscCxxErrorThrow()
315: {
316:   const char *str;
317:   if (eh && eh->ctx) {
318:     std::ostringstream *msg;
319:     msg = (std::ostringstream *)eh->ctx;
320:     str = msg->str().c_str();
321:   } else str = "Error detected in C PETSc";

323:   throw std::runtime_error(str);
324: }
325: #endif

327: /*@C
328:   PetscError - Routine that is called when an error has been detected, usually called through the macro `SETERRQ`(`PETSC_COMM_SELF`,)` or by `PetscCall()`.

330:   Collective

332:   Input Parameters:
333: + comm - communicator over which error occurred.  ALL MPI processes of this communicator MUST call this routine
334: . line - the line number of the error (usually indicated by `__LINE__` in the calling routine)
335: . func - the function name in which the error was detected
336: . file - the file in which the error was detected (usually indicated by `__FILE__` in the calling routine)
337: . n    - the generic error number
338: . p    - `PETSC_ERROR_INITIAL` indicates the error was initially detected, `PETSC_ERROR_REPEAT` indicates this is a traceback from a previously detected error
339: - mess - formatted message string - aka printf

341:   Options Database Keys:
342: + -error_output_stdout - output the error messages to `stdout` instead of the default `stderr`
343: - -error_output_none   - do not output the error messages

345:   Level: intermediate

347:   Notes:
348:   PETSc error handling is done with error return codes. A non-zero return indicates an error
349:   was detected. The return-value of this routine is what is ultimately returned by
350:   `SETERRQ()`.

352:   Numerical errors (potential divide by zero, for example) are not managed by the
353:   error return codes; they are managed via, for example, `KSPGetConvergedReason()` that
354:   indicates if the solve was successful or not. The option `-ksp_error_if_not_converged`, for
355:   example, turns numerical failures into hard errors managed via `PetscError()`.

357:   PETSc provides a rich supply of error handlers, see the list below, and users can also
358:   provide their own error handlers.

360:   If the user sets their own error handler (via `PetscPushErrorHandler()`) they may return any
361:   arbitrary value from it, but are encouraged to return nonzero values. If the return value is
362:   zero, `SETERRQ()` will ignore the value and return `PETSC_ERR_RETURN` (a nonzero value)
363:   instead.

365:   Most users need not directly use this routine and the error handlers, but can instead use
366:   the simplified interface `PetscCall()` or `SETERRQ()`.

368:   Fortran Note:
369:   This routine is used differently from Fortran
370: .vb
371:   PetscError(MPI_Comm comm, PetscErrorCode n, PetscErrorType p, char *message)
372: .ve

374:   Developer Note:
375:   Since this is called after an error condition it should not be calling any error handlers (currently it ignores any error codes)
376:   BUT this routine does call regular PETSc functions that may call error handlers, this is problematic and could be fixed by never calling other PETSc routines
377:   but this annoying.

379: .seealso: `PetscErrorCode`, `PetscPushErrorHandler()`, `PetscPopErrorHandler()`, `PetscTraceBackErrorHandler()`, `PetscAbortErrorHandler()`, `PetscMPIAbortErrorHandler()`,
380:           `PetscReturnErrorHandler()`, `PetscAttachDebuggerErrorHandler()`, `PetscEmacsClientErrorHandler()`,
381:           `SETERRQ()`, `PetscCall()`, `CHKMEMQ`, `PetscErrorMessage()`, `PETSCABORT()`, `PetscErrorType`, `PETSC_ERROR_INITIAL`, `PETSC_ERROR_REPEAT`
382: @*/
383: PetscErrorCode PetscError(MPI_Comm comm, int line, const char *func, const char *file, PetscErrorCode n, PetscErrorType p, const char *mess, ...)
384: {
385:   va_list        Argp;
386:   size_t         fullLength;
387:   char           buf[2048], *lbuf = NULL;
388:   PetscBool      ismain;
389:   PetscErrorCode ierr;

391:   if (!PetscErrorHandlingInitialized) return n;
392:   if (comm == MPI_COMM_NULL) comm = PETSC_COMM_SELF;

394:   /* Compose the message evaluating the print format */
395:   if (mess) {
396:     va_start(Argp, mess);
397:     ierr = PetscVSNPrintf(buf, 2048, mess, &fullLength, Argp);
398:     va_end(Argp);
399:     lbuf = buf;
400:     if (p == PETSC_ERROR_INITIAL) ierr = PetscStrncpy(PetscErrorBaseMessage, lbuf, sizeof(PetscErrorBaseMessage));
401:   }

403:   if (p == PETSC_ERROR_INITIAL && n != PETSC_ERR_MEMC) ierr = PetscMallocValidate(__LINE__, PETSC_FUNCTION_NAME, __FILE__);

405:   if (!eh) ierr = PetscTraceBackErrorHandler(comm, line, func, file, n, p, lbuf, NULL);
406:   else ierr = (*eh->handler)(comm, line, func, file, n, p, lbuf, eh->ctx);
407:   PetscStackClearTop;

409:   /*
410:       If this is called from the main() routine we abort the program.
411:       We cannot just return because them some MPI processes may continue to attempt to run
412:       while this process simply exits.
413:   */
414:   if (func) {
415:     PetscErrorCode cmp_ierr = PetscStrncmp(func, "main", 4, &ismain);
416:     if (ismain) {
417:       if (petscwaitonerrorflg) cmp_ierr = PetscSleep(1000);
418:       (void)cmp_ierr;
419:       PETSCABORT(comm, ierr);
420:     }
421:   }
422: #if defined(PETSC_CLANGUAGE_CXX)
423:   if (p == PETSC_ERROR_IN_CXX) PetscCxxErrorThrow();
424: #endif
425:   return ierr;
426: }

428: /*@C
429:   PetscIntView - Prints an array of integers; useful for debugging.

431:   Collective

433:   Input Parameters:
434: + N      - number of integers in array
435: . idx    - array of integers
436: - viewer - location to print array, `PETSC_VIEWER_STDOUT_WORLD`, `PETSC_VIEWER_STDOUT_SELF` or 0

438:   Level: intermediate

440:   Note:
441:   This may be called from within the debugger

443:   Developer Note:
444:   `idx` cannot be const because may be passed to binary viewer where temporary byte swapping may be done

446: .seealso: `PetscViewer`, `PetscRealView()`
447: @*/
448: PetscErrorCode PetscIntView(PetscInt N, const PetscInt idx[], PetscViewer viewer)
449: {
450:   PetscMPIInt rank, size;
451:   PetscInt    j, i, n = N / 20, p = N % 20;
452:   PetscBool   iascii, isbinary;
453:   MPI_Comm    comm;

455:   PetscFunctionBegin;
456:   if (!viewer) viewer = PETSC_VIEWER_STDOUT_SELF;
458:   if (N) PetscAssertPointer(idx, 2);
459:   PetscCall(PetscObjectGetComm((PetscObject)viewer, &comm));
460:   PetscCallMPI(MPI_Comm_size(comm, &size));
461:   PetscCallMPI(MPI_Comm_rank(comm, &rank));

463:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &iascii));
464:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
465:   if (iascii) {
466:     PetscCall(PetscViewerASCIIPushSynchronized(viewer));
467:     for (i = 0; i < n; i++) {
468:       if (size > 1) {
469:         PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "[%d] %" PetscInt_FMT ":", rank, 20 * i));
470:       } else {
471:         PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "%" PetscInt_FMT ":", 20 * i));
472:       }
473:       for (j = 0; j < 20; j++) PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, " %" PetscInt_FMT, idx[i * 20 + j]));
474:       PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "\n"));
475:     }
476:     if (p) {
477:       if (size > 1) {
478:         PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "[%d] %" PetscInt_FMT ":", rank, 20 * n));
479:       } else {
480:         PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "%" PetscInt_FMT ":", 20 * n));
481:       }
482:       for (i = 0; i < p; i++) PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, " %" PetscInt_FMT, idx[20 * n + i]));
483:       PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "\n"));
484:     }
485:     PetscCall(PetscViewerFlush(viewer));
486:     PetscCall(PetscViewerASCIIPopSynchronized(viewer));
487:   } else if (isbinary) {
488:     PetscMPIInt *sizes, Ntotal, *displs, NN;
489:     PetscInt    *array;

491:     PetscCall(PetscMPIIntCast(N, &NN));

493:     if (size > 1) {
494:       if (rank) {
495:         PetscCallMPI(MPI_Gather(&NN, 1, MPI_INT, NULL, 0, MPI_INT, 0, comm));
496:         PetscCallMPI(MPI_Gatherv((void *)idx, NN, MPIU_INT, NULL, NULL, NULL, MPIU_INT, 0, comm));
497:       } else {
498:         PetscCall(PetscMalloc1(size, &sizes));
499:         PetscCallMPI(MPI_Gather(&NN, 1, MPI_INT, sizes, 1, MPI_INT, 0, comm));
500:         Ntotal = sizes[0];
501:         PetscCall(PetscMalloc1(size, &displs));
502:         displs[0] = 0;
503:         for (i = 1; i < size; i++) {
504:           Ntotal += sizes[i];
505:           displs[i] = displs[i - 1] + sizes[i - 1];
506:         }
507:         PetscCall(PetscMalloc1(Ntotal, &array));
508:         PetscCallMPI(MPI_Gatherv((void *)idx, NN, MPIU_INT, array, sizes, displs, MPIU_INT, 0, comm));
509:         PetscCall(PetscViewerBinaryWrite(viewer, array, Ntotal, PETSC_INT));
510:         PetscCall(PetscFree(sizes));
511:         PetscCall(PetscFree(displs));
512:         PetscCall(PetscFree(array));
513:       }
514:     } else {
515:       PetscCall(PetscViewerBinaryWrite(viewer, idx, N, PETSC_INT));
516:     }
517:   } else {
518:     const char *tname;
519:     PetscCall(PetscObjectGetName((PetscObject)viewer, &tname));
520:     SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "Cannot handle that PetscViewer of type %s", tname);
521:   }
522:   PetscFunctionReturn(PETSC_SUCCESS);
523: }

525: /*@C
526:   PetscRealView - Prints an array of doubles; useful for debugging.

528:   Collective

530:   Input Parameters:
531: + N      - number of `PetscReal` in array
532: . idx    - array of `PetscReal`
533: - viewer - location to print array, `PETSC_VIEWER_STDOUT_WORLD`, `PETSC_VIEWER_STDOUT_SELF` or 0

535:   Level: intermediate

537:   Note:
538:   This may be called from within the debugger

540:   Developer Note:
541:   `idx` cannot be const because may be passed to binary viewer where temporary byte swapping may be done

543: .seealso: `PetscViewer`, `PetscIntView()`
544: @*/
545: PetscErrorCode PetscRealView(PetscInt N, const PetscReal idx[], PetscViewer viewer)
546: {
547:   PetscMPIInt rank, size;
548:   PetscInt    j, i, n = N / 5, p = N % 5;
549:   PetscBool   iascii, isbinary;
550:   MPI_Comm    comm;

552:   PetscFunctionBegin;
553:   if (!viewer) viewer = PETSC_VIEWER_STDOUT_SELF;
555:   PetscAssertPointer(idx, 2);
556:   PetscCall(PetscObjectGetComm((PetscObject)viewer, &comm));
557:   PetscCallMPI(MPI_Comm_size(comm, &size));
558:   PetscCallMPI(MPI_Comm_rank(comm, &rank));

560:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &iascii));
561:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
562:   if (iascii) {
563:     PetscInt tab;

565:     PetscCall(PetscViewerASCIIPushSynchronized(viewer));
566:     PetscCall(PetscViewerASCIIGetTab(viewer, &tab));
567:     for (i = 0; i < n; i++) {
568:       PetscCall(PetscViewerASCIISetTab(viewer, tab));
569:       if (size > 1) {
570:         PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "[%d] %2" PetscInt_FMT ":", rank, 5 * i));
571:       } else {
572:         PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "%2" PetscInt_FMT ":", 5 * i));
573:       }
574:       PetscCall(PetscViewerASCIISetTab(viewer, 0));
575:       for (j = 0; j < 5; j++) PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, " %12.4e", (double)idx[i * 5 + j]));
576:       PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "\n"));
577:     }
578:     if (p) {
579:       PetscCall(PetscViewerASCIISetTab(viewer, tab));
580:       if (size > 1) {
581:         PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "[%d] %2" PetscInt_FMT ":", rank, 5 * n));
582:       } else {
583:         PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "%2" PetscInt_FMT ":", 5 * n));
584:       }
585:       PetscCall(PetscViewerASCIISetTab(viewer, 0));
586:       for (i = 0; i < p; i++) PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, " %12.4e", (double)idx[5 * n + i]));
587:       PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "\n"));
588:     }
589:     PetscCall(PetscViewerFlush(viewer));
590:     PetscCall(PetscViewerASCIISetTab(viewer, tab));
591:     PetscCall(PetscViewerASCIIPopSynchronized(viewer));
592:   } else if (isbinary) {
593:     PetscMPIInt *sizes, *displs, Ntotal, NN;
594:     PetscReal   *array;

596:     PetscCall(PetscMPIIntCast(N, &NN));

598:     if (size > 1) {
599:       if (rank) {
600:         PetscCallMPI(MPI_Gather(&NN, 1, MPI_INT, NULL, 0, MPI_INT, 0, comm));
601:         PetscCallMPI(MPI_Gatherv((PetscReal *)idx, NN, MPIU_REAL, NULL, NULL, NULL, MPIU_REAL, 0, comm));
602:       } else {
603:         PetscCall(PetscMalloc1(size, &sizes));
604:         PetscCallMPI(MPI_Gather(&NN, 1, MPI_INT, sizes, 1, MPI_INT, 0, comm));
605:         Ntotal = sizes[0];
606:         PetscCall(PetscMalloc1(size, &displs));
607:         displs[0] = 0;
608:         for (i = 1; i < size; i++) {
609:           Ntotal += sizes[i];
610:           displs[i] = displs[i - 1] + sizes[i - 1];
611:         }
612:         PetscCall(PetscMalloc1(Ntotal, &array));
613:         PetscCallMPI(MPI_Gatherv((PetscReal *)idx, NN, MPIU_REAL, array, sizes, displs, MPIU_REAL, 0, comm));
614:         PetscCall(PetscViewerBinaryWrite(viewer, array, Ntotal, PETSC_REAL));
615:         PetscCall(PetscFree(sizes));
616:         PetscCall(PetscFree(displs));
617:         PetscCall(PetscFree(array));
618:       }
619:     } else {
620:       PetscCall(PetscViewerBinaryWrite(viewer, (void *)idx, N, PETSC_REAL));
621:     }
622:   } else {
623:     const char *tname;
624:     PetscCall(PetscObjectGetName((PetscObject)viewer, &tname));
625:     SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "Cannot handle that PetscViewer of type %s", tname);
626:   }
627:   PetscFunctionReturn(PETSC_SUCCESS);
628: }

630: /*@C
631:   PetscScalarView - Prints an array of `PetscScalar`; useful for debugging.

633:   Collective

635:   Input Parameters:
636: + N      - number of scalars in array
637: . idx    - array of scalars
638: - viewer - location to print array, `PETSC_VIEWER_STDOUT_WORLD`, `PETSC_VIEWER_STDOUT_SELF` or 0

640:   Level: intermediate

642:   Note:
643:   This may be called from within the debugger

645:   Developer Note:
646:   `idx` cannot be const because may be passed to binary viewer where byte swapping may be done

648: .seealso: `PetscViewer`, `PetscIntView()`, `PetscRealView()`
649: @*/
650: PetscErrorCode PetscScalarView(PetscInt N, const PetscScalar idx[], PetscViewer viewer)
651: {
652:   PetscMPIInt rank, size;
653:   PetscInt    j, i, n = N / 3, p = N % 3;
654:   PetscBool   iascii, isbinary;
655:   MPI_Comm    comm;

657:   PetscFunctionBegin;
658:   if (!viewer) viewer = PETSC_VIEWER_STDOUT_SELF;
660:   if (N) PetscAssertPointer(idx, 2);
661:   PetscCall(PetscObjectGetComm((PetscObject)viewer, &comm));
662:   PetscCallMPI(MPI_Comm_size(comm, &size));
663:   PetscCallMPI(MPI_Comm_rank(comm, &rank));

665:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &iascii));
666:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
667:   if (iascii) {
668:     PetscCall(PetscViewerASCIIPushSynchronized(viewer));
669:     for (i = 0; i < n; i++) {
670:       if (size > 1) {
671:         PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "[%d] %2" PetscInt_FMT ":", rank, 3 * i));
672:       } else {
673:         PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "%2" PetscInt_FMT ":", 3 * i));
674:       }
675:       for (j = 0; j < 3; j++) {
676: #if defined(PETSC_USE_COMPLEX)
677:         PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, " (%12.4e,%12.4e)", (double)PetscRealPart(idx[i * 3 + j]), (double)PetscImaginaryPart(idx[i * 3 + j])));
678: #else
679:         PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, " %12.4e", (double)idx[i * 3 + j]));
680: #endif
681:       }
682:       PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "\n"));
683:     }
684:     if (p) {
685:       if (size > 1) {
686:         PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "[%d] %2" PetscInt_FMT ":", rank, 3 * n));
687:       } else {
688:         PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "%2" PetscInt_FMT ":", 3 * n));
689:       }
690:       for (i = 0; i < p; i++) {
691: #if defined(PETSC_USE_COMPLEX)
692:         PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, " (%12.4e,%12.4e)", (double)PetscRealPart(idx[n * 3 + i]), (double)PetscImaginaryPart(idx[n * 3 + i])));
693: #else
694:         PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, " %12.4e", (double)idx[3 * n + i]));
695: #endif
696:       }
697:       PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "\n"));
698:     }
699:     PetscCall(PetscViewerFlush(viewer));
700:     PetscCall(PetscViewerASCIIPopSynchronized(viewer));
701:   } else if (isbinary) {
702:     PetscMPIInt *sizes, Ntotal, *displs, NN;
703:     PetscScalar *array;

705:     PetscCall(PetscMPIIntCast(N, &NN));

707:     if (size > 1) {
708:       if (rank) {
709:         PetscCallMPI(MPI_Gather(&NN, 1, MPI_INT, NULL, 0, MPI_INT, 0, comm));
710:         PetscCallMPI(MPI_Gatherv((void *)idx, NN, MPIU_SCALAR, NULL, NULL, NULL, MPIU_SCALAR, 0, comm));
711:       } else {
712:         PetscCall(PetscMalloc1(size, &sizes));
713:         PetscCallMPI(MPI_Gather(&NN, 1, MPI_INT, sizes, 1, MPI_INT, 0, comm));
714:         Ntotal = sizes[0];
715:         PetscCall(PetscMalloc1(size, &displs));
716:         displs[0] = 0;
717:         for (i = 1; i < size; i++) {
718:           Ntotal += sizes[i];
719:           displs[i] = displs[i - 1] + sizes[i - 1];
720:         }
721:         PetscCall(PetscMalloc1(Ntotal, &array));
722:         PetscCallMPI(MPI_Gatherv((void *)idx, NN, MPIU_SCALAR, array, sizes, displs, MPIU_SCALAR, 0, comm));
723:         PetscCall(PetscViewerBinaryWrite(viewer, array, Ntotal, PETSC_SCALAR));
724:         PetscCall(PetscFree(sizes));
725:         PetscCall(PetscFree(displs));
726:         PetscCall(PetscFree(array));
727:       }
728:     } else {
729:       PetscCall(PetscViewerBinaryWrite(viewer, (void *)idx, N, PETSC_SCALAR));
730:     }
731:   } else {
732:     const char *tname;
733:     PetscCall(PetscObjectGetName((PetscObject)viewer, &tname));
734:     SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "Cannot handle that PetscViewer of type %s", tname);
735:   }
736:   PetscFunctionReturn(PETSC_SUCCESS);
737: }

739: #if defined(PETSC_HAVE_CUDA)
740: #include <petscdevice_cuda.h>
741: PETSC_EXTERN const char *PetscCUBLASGetErrorName(cublasStatus_t status)
742: {
743:   switch (status) {
744:   #if (CUDART_VERSION >= 8000) /* At least CUDA 8.0 of Sep. 2016 had these */
745:   case CUBLAS_STATUS_SUCCESS:
746:     return "CUBLAS_STATUS_SUCCESS";
747:   case CUBLAS_STATUS_NOT_INITIALIZED:
748:     return "CUBLAS_STATUS_NOT_INITIALIZED";
749:   case CUBLAS_STATUS_ALLOC_FAILED:
750:     return "CUBLAS_STATUS_ALLOC_FAILED";
751:   case CUBLAS_STATUS_INVALID_VALUE:
752:     return "CUBLAS_STATUS_INVALID_VALUE";
753:   case CUBLAS_STATUS_ARCH_MISMATCH:
754:     return "CUBLAS_STATUS_ARCH_MISMATCH";
755:   case CUBLAS_STATUS_MAPPING_ERROR:
756:     return "CUBLAS_STATUS_MAPPING_ERROR";
757:   case CUBLAS_STATUS_EXECUTION_FAILED:
758:     return "CUBLAS_STATUS_EXECUTION_FAILED";
759:   case CUBLAS_STATUS_INTERNAL_ERROR:
760:     return "CUBLAS_STATUS_INTERNAL_ERROR";
761:   case CUBLAS_STATUS_NOT_SUPPORTED:
762:     return "CUBLAS_STATUS_NOT_SUPPORTED";
763:   case CUBLAS_STATUS_LICENSE_ERROR:
764:     return "CUBLAS_STATUS_LICENSE_ERROR";
765:   #endif
766:   default:
767:     return "unknown error";
768:   }
769: }
770: PETSC_EXTERN const char *PetscCUSolverGetErrorName(cusolverStatus_t status)
771: {
772:   switch (status) {
773:   #if (CUDART_VERSION >= 8000) /* At least CUDA 8.0 of Sep. 2016 had these */
774:   case CUSOLVER_STATUS_SUCCESS:
775:     return "CUSOLVER_STATUS_SUCCESS";
776:   case CUSOLVER_STATUS_NOT_INITIALIZED:
777:     return "CUSOLVER_STATUS_NOT_INITIALIZED";
778:   case CUSOLVER_STATUS_INVALID_VALUE:
779:     return "CUSOLVER_STATUS_INVALID_VALUE";
780:   case CUSOLVER_STATUS_ARCH_MISMATCH:
781:     return "CUSOLVER_STATUS_ARCH_MISMATCH";
782:   case CUSOLVER_STATUS_INTERNAL_ERROR:
783:     return "CUSOLVER_STATUS_INTERNAL_ERROR";
784:     #if (CUDART_VERSION >= 9000) /* CUDA 9.0 had these defined on June 2021 */
785:   case CUSOLVER_STATUS_ALLOC_FAILED:
786:     return "CUSOLVER_STATUS_ALLOC_FAILED";
787:   case CUSOLVER_STATUS_MAPPING_ERROR:
788:     return "CUSOLVER_STATUS_MAPPING_ERROR";
789:   case CUSOLVER_STATUS_EXECUTION_FAILED:
790:     return "CUSOLVER_STATUS_EXECUTION_FAILED";
791:   case CUSOLVER_STATUS_MATRIX_TYPE_NOT_SUPPORTED:
792:     return "CUSOLVER_STATUS_MATRIX_TYPE_NOT_SUPPORTED";
793:   case CUSOLVER_STATUS_NOT_SUPPORTED:
794:     return "CUSOLVER_STATUS_NOT_SUPPORTED ";
795:   case CUSOLVER_STATUS_ZERO_PIVOT:
796:     return "CUSOLVER_STATUS_ZERO_PIVOT";
797:   case CUSOLVER_STATUS_INVALID_LICENSE:
798:     return "CUSOLVER_STATUS_INVALID_LICENSE";
799:     #endif
800:   #endif
801:   default:
802:     return "unknown error";
803:   }
804: }
805: PETSC_EXTERN const char *PetscCUFFTGetErrorName(cufftResult result)
806: {
807:   switch (result) {
808:   case CUFFT_SUCCESS:
809:     return "CUFFT_SUCCESS";
810:   case CUFFT_INVALID_PLAN:
811:     return "CUFFT_INVALID_PLAN";
812:   case CUFFT_ALLOC_FAILED:
813:     return "CUFFT_ALLOC_FAILED";
814:   case CUFFT_INVALID_TYPE:
815:     return "CUFFT_INVALID_TYPE";
816:   case CUFFT_INVALID_VALUE:
817:     return "CUFFT_INVALID_VALUE";
818:   case CUFFT_INTERNAL_ERROR:
819:     return "CUFFT_INTERNAL_ERROR";
820:   case CUFFT_EXEC_FAILED:
821:     return "CUFFT_EXEC_FAILED";
822:   case CUFFT_SETUP_FAILED:
823:     return "CUFFT_SETUP_FAILED";
824:   case CUFFT_INVALID_SIZE:
825:     return "CUFFT_INVALID_SIZE";
826:   case CUFFT_UNALIGNED_DATA:
827:     return "CUFFT_UNALIGNED_DATA";
828:   case CUFFT_INCOMPLETE_PARAMETER_LIST:
829:     return "CUFFT_INCOMPLETE_PARAMETER_LIST";
830:   case CUFFT_INVALID_DEVICE:
831:     return "CUFFT_INVALID_DEVICE";
832:   case CUFFT_PARSE_ERROR:
833:     return "CUFFT_PARSE_ERROR";
834:   case CUFFT_NO_WORKSPACE:
835:     return "CUFFT_NO_WORKSPACE";
836:   case CUFFT_NOT_IMPLEMENTED:
837:     return "CUFFT_NOT_IMPLEMENTED";
838:   case CUFFT_LICENSE_ERROR:
839:     return "CUFFT_LICENSE_ERROR";
840:   case CUFFT_NOT_SUPPORTED:
841:     return "CUFFT_NOT_SUPPORTED";
842:   default:
843:     return "unknown error";
844:   }
845: }
846: #endif

848: #if defined(PETSC_HAVE_HIP)
849: #include <petscdevice_hip.h>
850: PETSC_EXTERN const char *PetscHIPBLASGetErrorName(hipblasStatus_t status)
851: {
852:   switch (status) {
853:   case HIPBLAS_STATUS_SUCCESS:
854:     return "HIPBLAS_STATUS_SUCCESS";
855:   case HIPBLAS_STATUS_NOT_INITIALIZED:
856:     return "HIPBLAS_STATUS_NOT_INITIALIZED";
857:   case HIPBLAS_STATUS_ALLOC_FAILED:
858:     return "HIPBLAS_STATUS_ALLOC_FAILED";
859:   case HIPBLAS_STATUS_INVALID_VALUE:
860:     return "HIPBLAS_STATUS_INVALID_VALUE";
861:   case HIPBLAS_STATUS_ARCH_MISMATCH:
862:     return "HIPBLAS_STATUS_ARCH_MISMATCH";
863:   case HIPBLAS_STATUS_MAPPING_ERROR:
864:     return "HIPBLAS_STATUS_MAPPING_ERROR";
865:   case HIPBLAS_STATUS_EXECUTION_FAILED:
866:     return "HIPBLAS_STATUS_EXECUTION_FAILED";
867:   case HIPBLAS_STATUS_INTERNAL_ERROR:
868:     return "HIPBLAS_STATUS_INTERNAL_ERROR";
869:   case HIPBLAS_STATUS_NOT_SUPPORTED:
870:     return "HIPBLAS_STATUS_NOT_SUPPORTED";
871:   default:
872:     return "unknown error";
873:   }
874: }
875: PETSC_EXTERN const char *PetscHIPSPARSEGetErrorName(hipsparseStatus_t status)
876: {
877:   switch (status) {
878:   case HIPSPARSE_STATUS_SUCCESS:
879:     return "HIPSPARSE_STATUS_SUCCESS";
880:   case HIPSPARSE_STATUS_NOT_INITIALIZED:
881:     return "HIPSPARSE_STATUS_NOT_INITIALIZED";
882:   case HIPSPARSE_STATUS_ALLOC_FAILED:
883:     return "HIPSPARSE_STATUS_ALLOC_FAILED";
884:   case HIPSPARSE_STATUS_INVALID_VALUE:
885:     return "HIPSPARSE_STATUS_INVALID_VALUE";
886:   case HIPSPARSE_STATUS_ARCH_MISMATCH:
887:     return "HIPSPARSE_STATUS_ARCH_MISMATCH";
888:   case HIPSPARSE_STATUS_MAPPING_ERROR:
889:     return "HIPSPARSE_STATUS_MAPPING_ERROR";
890:   case HIPSPARSE_STATUS_EXECUTION_FAILED:
891:     return "HIPSPARSE_STATUS_EXECUTION_FAILED";
892:   case HIPSPARSE_STATUS_INTERNAL_ERROR:
893:     return "HIPSPARSE_STATUS_INTERNAL_ERROR";
894:   case HIPSPARSE_STATUS_MATRIX_TYPE_NOT_SUPPORTED:
895:     return "HIPSPARSE_STATUS_MATRIX_TYPE_NOT_SUPPORTED";
896:   case HIPSPARSE_STATUS_ZERO_PIVOT:
897:     return "HIPSPARSE_STATUS_ZERO_PIVOT";
898:   case HIPSPARSE_STATUS_NOT_SUPPORTED:
899:     return "HIPSPARSE_STATUS_NOT_SUPPORTED";
900:   case HIPSPARSE_STATUS_INSUFFICIENT_RESOURCES:
901:     return "HIPSPARSE_STATUS_INSUFFICIENT_RESOURCES";
902:   default:
903:     return "unknown error";
904:   }
905: }
906: PETSC_EXTERN const char *PetscHIPSolverGetErrorName(hipsolverStatus_t status)
907: {
908:   switch (status) {
909:   case HIPSOLVER_STATUS_SUCCESS:
910:     return "HIPSOLVER_STATUS_SUCCESS";
911:   case HIPSOLVER_STATUS_NOT_INITIALIZED:
912:     return "HIPSOLVER_STATUS_NOT_INITIALIZED";
913:   case HIPSOLVER_STATUS_ALLOC_FAILED:
914:     return "HIPSOLVER_STATUS_ALLOC_FAILED";
915:   case HIPSOLVER_STATUS_MAPPING_ERROR:
916:     return "HIPSOLVER_STATUS_MAPPING_ERROR";
917:   case HIPSOLVER_STATUS_INVALID_VALUE:
918:     return "HIPSOLVER_STATUS_INVALID_VALUE";
919:   case HIPSOLVER_STATUS_EXECUTION_FAILED:
920:     return "HIPSOLVER_STATUS_EXECUTION_FAILED";
921:   case HIPSOLVER_STATUS_INTERNAL_ERROR:
922:     return "HIPSOLVER_STATUS_INTERNAL_ERROR";
923:   case HIPSOLVER_STATUS_NOT_SUPPORTED:
924:     return "HIPSOLVER_STATUS_NOT_SUPPORTED ";
925:   case HIPSOLVER_STATUS_ARCH_MISMATCH:
926:     return "HIPSOLVER_STATUS_ARCH_MISMATCH";
927:   case HIPSOLVER_STATUS_HANDLE_IS_NULLPTR:
928:     return "HIPSOLVER_STATUS_HANDLE_IS_NULLPTR";
929:   case HIPSOLVER_STATUS_INVALID_ENUM:
930:     return "HIPSOLVER_STATUS_INVALID_ENUM";
931:   case HIPSOLVER_STATUS_UNKNOWN:
932:   default:
933:     return "HIPSOLVER_STATUS_UNKNOWN";
934:   }
935: }
936: #endif

938: /*@C
939:   PetscMPIErrorString - Given an MPI error code returns the `MPI_Error_string()` appropriately
940:   formatted for displaying with the PETSc error handlers.

942:   Input Parameter:
943: . err - the MPI error code

945:   Output Parameter:
946: . string - the MPI error message, should declare its length to be larger than `MPI_MAX_ERROR_STRING`

948:   Level: developer

950:   Note:
951:   Does not return an error code or do error handling because it may be called from inside an error handler

953: .seealso: `PetscErrorCode` `PetscErrorMessage()`
954: @*/
955: void PetscMPIErrorString(PetscMPIInt err, char *string)
956: {
957:   char        errorstring[MPI_MAX_ERROR_STRING];
958:   PetscMPIInt len, j = 0;

960:   MPI_Error_string(err, (char *)errorstring, &len);
961:   for (PetscMPIInt i = 0; i < len; i++) {
962:     string[j++] = errorstring[i];
963:     if (errorstring[i] == '\n') {
964:       for (PetscMPIInt k = 0; k < 16; k++) string[j++] = ' ';
965:     }
966:   }
967:   string[j] = 0;
968: }