Add a special Error * that can be passed to error handling APIs to signal that any errors are fatal and should abort QEMU. There are two advantages to this: - allows for brevity when wishing to assert success of Error ** accepting APIs. No need for this pattern: Error * local_err = NULL; api_call(foo, bar, &local_err); assert_no_error(local_err); This also removes the need for _nofail variants of APIs with asserting call sites now reduced to 1LOC. - SIGABRT happens from within the offending API. When a fatal error occurs in an API call (when the caller is asserting sucess) failure often means the API itself is broken. With the abort happening in the API call now, the stack frames into the call are available at debug time. In the assert_no_error scheme the abort happens after the fact. The exact semantic is that when an error is raised, if the argument Error ** matches &error_abort, then the abort occurs immediately. The error messaged is reported. For error_propagate, if the destination error is &error_abort, then the abort happens at propagation time. Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
105 lines
2.8 KiB
C
105 lines
2.8 KiB
C
/*
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* QEMU Error Objects
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*
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* Copyright IBM, Corp. 2011
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*
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* Authors:
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* Anthony Liguori <aliguori@us.ibm.com>
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*
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* This work is licensed under the terms of the GNU LGPL, version 2. See
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* the COPYING.LIB file in the top-level directory.
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*/
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#ifndef ERROR_H
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#define ERROR_H
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#include "qemu/compiler.h"
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#include "qapi-types.h"
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#include <stdbool.h>
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/**
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* A class representing internal errors within QEMU. An error has a ErrorClass
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* code and a human message.
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*/
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typedef struct Error Error;
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/**
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* Set an indirect pointer to an error given a ErrorClass value and a
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* printf-style human message. This function is not meant to be used outside
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* of QEMU.
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*/
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void error_set(Error **err, ErrorClass err_class, const char *fmt, ...) GCC_FMT_ATTR(3, 4);
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/**
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* Set an indirect pointer to an error given a ErrorClass value and a
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* printf-style human message, followed by a strerror() string if
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* @os_error is not zero.
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*/
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void error_set_errno(Error **err, int os_error, ErrorClass err_class, const char *fmt, ...) GCC_FMT_ATTR(4, 5);
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#ifdef _WIN32
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/**
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* Set an indirect pointer to an error given a ErrorClass value and a
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* printf-style human message, followed by a g_win32_error_message() string if
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* @win32_err is not zero.
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*/
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void error_set_win32(Error **err, int win32_err, ErrorClass err_class, const char *fmt, ...) GCC_FMT_ATTR(4, 5);
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#endif
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/**
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* Same as error_set(), but sets a generic error
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*/
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#define error_setg(err, fmt, ...) \
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error_set(err, ERROR_CLASS_GENERIC_ERROR, fmt, ## __VA_ARGS__)
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#define error_setg_errno(err, os_error, fmt, ...) \
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error_set_errno(err, os_error, ERROR_CLASS_GENERIC_ERROR, fmt, ## __VA_ARGS__)
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#ifdef _WIN32
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#define error_setg_win32(err, win32_err, fmt, ...) \
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error_set_win32(err, win32_err, ERROR_CLASS_GENERIC_ERROR, fmt, ## __VA_ARGS__)
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#endif
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/**
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* Helper for open() errors
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*/
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void error_setg_file_open(Error **errp, int os_errno, const char *filename);
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/**
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* Returns true if an indirect pointer to an error is pointing to a valid
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* error object.
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*/
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bool error_is_set(Error **err);
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/*
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* Get the error class of an error object.
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*/
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ErrorClass error_get_class(const Error *err);
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/**
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* Returns an exact copy of the error passed as an argument.
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*/
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Error *error_copy(const Error *err);
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/**
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* Get a human readable representation of an error object.
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*/
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const char *error_get_pretty(Error *err);
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/**
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* Propagate an error to an indirect pointer to an error. This function will
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* always transfer ownership of the error reference and handles the case where
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* dst_err is NULL correctly. Errors after the first are discarded.
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*/
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void error_propagate(Error **dst_err, Error *local_err);
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/**
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* Free an error object.
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*/
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void error_free(Error *err);
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/**
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* If passed to error_set and friends, abort().
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*/
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extern Error *error_abort;
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#endif
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