GDAL
Macros | Typedefs | Enumerations | Functions
cpl_error.h File Reference

CPL error handling services. More...

#include "cpl_port.h"
#include <stdarg.h>
#include <stddef.h>

Go to the source code of this file.

Macros

#define CPLE_None   0
 No error.
 
#define CPLE_AppDefined   1
 Application defined error.
 
#define CPLE_OutOfMemory   2
 Out of memory error.
 
#define CPLE_FileIO   3
 File I/O error.
 
#define CPLE_OpenFailed   4
 Open failed.
 
#define CPLE_IllegalArg   5
 Illegal argument.
 
#define CPLE_NotSupported   6
 Not supported.
 
#define CPLE_AssertionFailed   7
 Assertion failed.
 
#define CPLE_NoWriteAccess   8
 No write access.
 
#define CPLE_UserInterrupt   9
 User interrupted.
 
#define CPLE_ObjectNull   10
 NULL object.
 
#define CPLE_HttpResponse   11
 HTTP response.
 
#define CPLE_AWSBucketNotFound   12
 AWSBucketNotFound.
 
#define CPLE_AWSObjectNotFound   13
 AWSObjectNotFound.
 
#define CPLE_AWSAccessDenied   14
 AWSAccessDenied.
 
#define CPLE_AWSInvalidCredentials   15
 AWSInvalidCredentials.
 
#define CPLE_AWSSignatureDoesNotMatch   16
 AWSSignatureDoesNotMatch.
 
#define CPLAssert(expr)
 Assert on an expression. More...
 
#define VALIDATE_POINTER0(ptr, func)
 Validate that a pointer is not NULL. More...
 
#define VALIDATE_POINTER1(ptr, func, rc)
 Validate that a pointer is not NULL, and return rc if it is NULL. More...
 

Typedefs

typedef int CPLErrorNum
 Error number.
 
typedef void(* CPLErrorHandler )(CPLErr, CPLErrorNum, const char *)
 Callback for a custom error handler.
 

Enumerations

enum  CPLErr {
  CE_None = 0, CE_Debug = 1, CE_Warning = 2, CE_Failure = 3,
  CE_Fatal = 4
}
 Error category.
 

Functions

void CPLError (CPLErr eErrClass, CPLErrorNum err_no, const char *fmt,...)
 Report an error. More...
 
void CPLErrorV (CPLErr, CPLErrorNum, const char *, va_list)
 Same as CPLError() but with a va_list.
 
void CPLEmergencyError (const char *) CPL_NO_RETURN
 Fatal error when things are bad. More...
 
void CPLErrorReset (void)
 Erase any traces of previous errors. More...
 
CPLErrorNum CPLGetLastErrorNo (void)
 Fetch the last error number. More...
 
CPLErr CPLGetLastErrorType (void)
 Fetch the last error type. More...
 
const char * CPLGetLastErrorMsg (void)
 Get the last error message. More...
 
GUInt32 CPLGetErrorCounter (void)
 Get the error counter. More...
 
void * CPLGetErrorHandlerUserData (void)
 Fetch the user data for the error context. More...
 
void CPLErrorSetState (CPLErr eErrClass, CPLErrorNum err_no, const char *pszMsg)
 Restore an error state, without emitting an error. More...
 
void CPLLoggingErrorHandler (CPLErr, CPLErrorNum, const char *)
 Error handler that logs into the file defined by the CPL_LOG configuration option, or stderr otherwise.
 
void CPLDefaultErrorHandler (CPLErr, CPLErrorNum, const char *)
 Default error handler. More...
 
void CPLQuietErrorHandler (CPLErr, CPLErrorNum, const char *)
 Error handler that does not do anything, except for debug messages. More...
 
void CPLTurnFailureIntoWarning (int bOn)
 Whether failures should be turned into warnings.
 
CPLErrorHandler CPLSetErrorHandler (CPLErrorHandler)
 Install custom error handler. More...
 
CPLErrorHandler CPLSetErrorHandlerEx (CPLErrorHandler, void *)
 Install custom error handle with user's data. More...
 
void CPLPushErrorHandler (CPLErrorHandler)
 Push a new CPLError handler. More...
 
void CPLPushErrorHandlerEx (CPLErrorHandler, void *)
 Push a new CPLError handler with user data on the error context. More...
 
void CPLSetCurrentErrorHandlerCatchDebug (int bCatchDebug)
 Set if the current error handler should intercept debug messages, or if they should be processed by the previous handler. More...
 
void CPLPopErrorHandler (void)
 Pop error handler off stack. More...
 
void CPLDebug (const char *, const char *,...)
 Display a debugging message. More...
 
void _CPLAssert (const char *, const char *, int) CPL_NO_RETURN
 Report failure of a logical assertion. More...
 

Detailed Description

CPL error handling services.

Macro Definition Documentation

#define CPLAssert (   expr)

Assert on an expression.

Only enabled in DEBUG mode

#define VALIDATE_POINTER0 (   ptr,
  func 
)
Value:
do { if( NULL == ptr ) \
{ \
CPLErr const ret = VALIDATE_POINTER_ERR; \
"Pointer \'%s\' is NULL in \'%s\'.\n", #ptr, (func)); \
return; }} while(0)
#define CPLE_ObjectNull
NULL object.
Definition: cpl_error.h:117
void CPLError(CPLErr eErrClass, CPLErrorNum err_no, const char *fmt,...)
Report an error.
Definition: cpl_error.cpp:228
CPLErr
Error category.
Definition: cpl_error.h:52

Validate that a pointer is not NULL.

#define VALIDATE_POINTER1 (   ptr,
  func,
  rc 
)
Value:
do { if( NULL == ptr ) \
{ \
CPLErr const ret = VALIDATE_POINTER_ERR; \
"Pointer \'%s\' is NULL in \'%s\'.\n", #ptr, (func)); \
return (rc); }} while(0)
#define CPLE_ObjectNull
NULL object.
Definition: cpl_error.h:117
void CPLError(CPLErr eErrClass, CPLErrorNum err_no, const char *fmt,...)
Report an error.
Definition: cpl_error.cpp:228
CPLErr
Error category.
Definition: cpl_error.h:52

Validate that a pointer is not NULL, and return rc if it is NULL.

Function Documentation

void _CPLAssert ( const char *  pszExpression,
const char *  pszFile,
int  iLine 
)

Report failure of a logical assertion.

Applications would normally use the CPLAssert() macro which expands into code calling _CPLAssert() only if the condition fails. _CPLAssert() will generate a CE_Fatal error call to CPLError(), indicating the file name, and line number of the failed assertion, as well as containing the assertion itself.

There is no reason for application code to call _CPLAssert() directly.

void CPLDebug ( const char *  pszCategory,
const char *  pszFormat,
  ... 
)

Display a debugging message.

The category argument is used in conjunction with the CPL_DEBUG environment variable to establish if the message should be displayed. If the CPL_DEBUG environment variable is not set, no debug messages are emitted (use CPLError(CE_Warning, ...) to ensure messages are displayed). If CPL_DEBUG is set, but is an empty string or the word "ON" then all debug messages are shown. Otherwise only messages whose category appears somewhere within the CPL_DEBUG value are displayed (as determined by strstr()).

Categories are usually an identifier for the subsystem producing the error. For instance "GDAL" might be used for the GDAL core, and "TIFF" for messages from the TIFF translator.

Parameters
pszCategoryname of the debugging message category.
pszFormatprintf() style format string for message to display. Remaining arguments are assumed to be for format.
void CPLDefaultErrorHandler ( CPLErr  eErrClass,
CPLErrorNum  nError,
const char *  pszErrorMsg 
)

Default error handler.

void CPLEmergencyError ( const char *  pszMessage)

Fatal error when things are bad.

This function should be called in an emergency situation where it is unlikely that a regular error report would work. This would include in the case of heap exhaustion for even small allocations, or any failure in the process of reporting an error (such as TLS allocations).

This function should never return. After the error message has been reported as best possible, the application will abort() similarly to how CPLError() aborts on CE_Fatal class errors.

Parameters
pszMessagethe error message to report.
void CPLError ( CPLErr  eErrClass,
CPLErrorNum  err_no,
const char *  fmt,
  ... 
)

Report an error.

This function reports an error in a manner that can be hooked and reported appropriate by different applications.

The effect of this function can be altered by applications by installing a custom error handling using CPLSetErrorHandler().

The eErrClass argument can have the value CE_Warning indicating that the message is an informational warning, CE_Failure indicating that the action failed, but that normal recover mechanisms will be used or CE_Fatal meaning that a fatal error has occurred, and that CPLError() should not return.

The default behaviour of CPLError() is to report errors to stderr, and to abort() after reporting a CE_Fatal error. It is expected that some applications will want to suppress error reporting, and will want to install a C++ exception, or longjmp() approach to no local fatal error recovery.

Regardless of how application error handlers or the default error handler choose to handle an error, the error number, and message will be stored for recovery with CPLGetLastErrorNo() and CPLGetLastErrorMsg().

Parameters
eErrClassone of CE_Warning, CE_Failure or CE_Fatal.
err_nothe error number (CPLE_*) from cpl_error.h.
fmta printf() style format string. Any additional arguments will be treated as arguments to fill in this format in a manner similar to printf().
void CPLErrorReset ( void  )

Erase any traces of previous errors.

This is normally used to ensure that an error which has been recovered from does not appear to be still in play with high level functions.

void CPLErrorSetState ( CPLErr  eErrClass,
CPLErrorNum  err_no,
const char *  pszMsg 
)

Restore an error state, without emitting an error.

Can be useful if a routine might call CPLErrorReset() and one wants to preserve the previous error state.

Since
GDAL 2.0
GUInt32 CPLGetErrorCounter ( void  )

Get the error counter.

Fetches the number of errors emitted in the current error context, since the last call to CPLErrorReset()

Returns
the error counter.
Since
GDAL 2.3
void* CPLGetErrorHandlerUserData ( void  )

Fetch the user data for the error context.

Fetches the user data for the current error context. You can set the user data for the error context when you add your handler by issuing CPLSetErrorHandlerEx() and CPLPushErrorHandlerEx(). Note that user data is primarily intended for providing context within error handlers themselves, but they could potentially be abused in other useful ways with the usual caveat emptor understanding.

Returns
the user data pointer for the error context
const char* CPLGetLastErrorMsg ( void  )

Get the last error message.

Fetches the last error message posted with CPLError(), that hasn't been cleared by CPLErrorReset(). The returned pointer is to an internal string that should not be altered or freed.

Returns
the last error message, or NULL if there is no posted error message.
CPLErrorNum CPLGetLastErrorNo ( void  )

Fetch the last error number.

Fetches the last error number posted with CPLError(), that hasn't been cleared by CPLErrorReset(). This is the error number, not the error class.

Returns
the error number of the last error to occur, or CPLE_None (0) if there are no posted errors.
CPLErr CPLGetLastErrorType ( void  )

Fetch the last error type.

Fetches the last error type posted with CPLError(), that hasn't been cleared by CPLErrorReset(). This is the error class, not the error number.

Returns
the error type of the last error to occur, or CE_None (0) if there are no posted errors.
void CPLPopErrorHandler ( void  )

Pop error handler off stack.

Discards the current error handler on the error handler stack, and restores the one in use before the last CPLPushErrorHandler() call. This method has no effect if there are no error handlers on the current threads error handler stack.

void CPLPushErrorHandler ( CPLErrorHandler  pfnErrorHandlerNew)

Push a new CPLError handler.

This pushes a new error handler on the thread-local error handler stack. This handler will be used until removed with CPLPopErrorHandler().

The CPLSetErrorHandler() docs have further information on how CPLError handlers work.

Parameters
pfnErrorHandlerNewnew error handler function.
void CPLPushErrorHandlerEx ( CPLErrorHandler  pfnErrorHandlerNew,
void *  pUserData 
)

Push a new CPLError handler with user data on the error context.

This pushes a new error handler on the thread-local error handler stack. This handler will be used until removed with CPLPopErrorHandler(). Obtain the user data back by using CPLGetErrorContext().

The CPLSetErrorHandler() docs have further information on how CPLError handlers work.

Parameters
pfnErrorHandlerNewnew error handler function.
pUserDataUser data to put on the error context.
void CPLQuietErrorHandler ( CPLErr  eErrClass,
CPLErrorNum  nError,
const char *  pszErrorMsg 
)

Error handler that does not do anything, except for debug messages.

void CPLSetCurrentErrorHandlerCatchDebug ( int  bCatchDebug)

Set if the current error handler should intercept debug messages, or if they should be processed by the previous handler.

By default when installing a custom error handler, this one intercepts debug messages. In some cases, this might not be desirable and the user would prefer that the previous installed handler (or the default one if no previous installed handler exists in the stack) deal with it. In which case, this function should be called with bCatchDebug.

Parameters
bCatchDebugFALSE if the current error handler should not intercept debug messages
Since
GDAL 2.1
CPLErrorHandler CPLSetErrorHandler ( CPLErrorHandler  pfnErrorHandlerNew)

Install custom error handler.

Allow the library's user to specify an error handler function. A valid error handler is a C function with the following prototype:

    void MyErrorHandler(CPLErr eErrClass, int err_no, const char *msg)

Pass NULL to come back to the default behavior. The default behaviour (CPLDefaultErrorHandler()) is to write the message to stderr.

The msg will be a partially formatted error message not containing the "ERROR %d:" portion emitted by the default handler. Message formatting is handled by CPLError() before calling the handler. If the error handler function is passed a CE_Fatal class error and returns, then CPLError() will call abort(). Applications wanting to interrupt this fatal behaviour will have to use longjmp(), or a C++ exception to indirectly exit the function.

Another standard error handler is CPLQuietErrorHandler() which doesn't make any attempt to report the passed error or warning messages but will process debug messages via CPLDefaultErrorHandler.

Note that error handlers set with CPLSetErrorHandler() apply to all threads in an application, while error handlers set with CPLPushErrorHandler are thread-local. However, any error handlers pushed with CPLPushErrorHandler (and not removed with CPLPopErrorHandler) take precedence over the global error handlers set with CPLSetErrorHandler(). Generally speaking CPLSetErrorHandler() would be used to set a desired global error handler, while CPLPushErrorHandler() would be used to install a temporary local error handler, such as CPLQuietErrorHandler() to suppress error reporting in a limited segment of code.

Parameters
pfnErrorHandlerNewnew error handler function.
Returns
returns the previously installed error handler.
CPLErrorHandler CPLSetErrorHandlerEx ( CPLErrorHandler  pfnErrorHandlerNew,
void *  pUserData 
)

Install custom error handle with user's data.

This method is essentially CPLSetErrorHandler with an added pointer to pUserData. The pUserData is not returned in the CPLErrorHandler, however, and must be fetched via CPLGetErrorHandlerUserData.

Parameters
pfnErrorHandlerNewnew error handler function.
pUserDataUser data to carry along with the error context.
Returns
returns the previously installed error handler.

Generated for GDAL by doxygen 1.8.8.