qemu-e2k/error.h
Paolo Bonzini d195325b05 qapi: fix error propagation
Don't overwrite / leak previously set errors.
Make traversal cope with missing mandatory sub-structs.
Don't try to end a container that could not be started.

v1->v2:
- unchanged

v2->v3:
- instead of examining, assert that we never overwrite errors with
  error_set()
- allow visitors to set a NULL struct pointer successfully, so traversal
  of incomplete objects can continue
- check for a NULL "obj" before accessing "(*obj)->has_XXX" (this is not a
  typo, "obj != NULL" implies "*obj != NULL" here)
- fix start_struct / end_struct balance for unions as well

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-07-23 11:55:17 +01:00

76 lines
1.9 KiB
C

/*
* QEMU Error Objects
*
* Copyright IBM, Corp. 2011
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
*
* This work is licensed under the terms of the GNU LGPL, version 2. See
* the COPYING.LIB file in the top-level directory.
*/
#ifndef ERROR_H
#define ERROR_H
#include "compiler.h"
#include <stdbool.h>
/**
* A class representing internal errors within QEMU. An error has a string
* typename and optionally a set of named string parameters.
*/
typedef struct Error Error;
/**
* Set an indirect pointer to an error given a printf-style format parameter.
* Currently, qerror.h defines these error formats. This function is not
* meant to be used outside of QEMU.
*/
void error_set(Error **err, const char *fmt, ...) GCC_FMT_ATTR(2, 3);
/**
* Returns true if an indirect pointer to an error is pointing to a valid
* error object.
*/
bool error_is_set(Error **err);
/**
* Returns an exact copy of the error passed as an argument.
*/
Error *error_copy(const Error *err);
/**
* Get a human readable representation of an error object.
*/
const char *error_get_pretty(Error *err);
/**
* Get an individual named error field.
*/
const char *error_get_field(Error *err, const char *field);
/**
* Get an individual named error field.
*/
void error_set_field(Error *err, const char *field, const char *value);
/**
* Propagate an error to an indirect pointer to an error. This function will
* always transfer ownership of the error reference and handles the case where
* dst_err is NULL correctly. Errors after the first are discarded.
*/
void error_propagate(Error **dst_err, Error *local_err);
/**
* Free an error object.
*/
void error_free(Error *err);
/**
* Determine if an error is of a speific type (based on the qerror format).
* Non-QEMU users should get the `class' field to identify the error type.
*/
bool error_is_type(Error *err, const char *fmt);
#endif