/**
* @copyright
* ====================================================================
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
* ====================================================================
* @endcopyright
*
* @file svn_error.h
* @brief Common exception handling for Subversion.
*/
#ifndef SVN_ERROR_H
#define SVN_ERROR_H
#include <apr.h> /* for apr_size_t */
#include <apr_errno.h> /* APR's error system */
#include <apr_pools.h> /* for apr_pool_t */
#ifndef DOXYGEN_SHOULD_SKIP_THIS
#define APR_WANT_STDIO
#endif
#include <apr_want.h> /* for FILE* */
#include "svn_types.h"
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
/* For the Subversion developers, this #define turns on extended "stack
traces" of any errors that get thrown. See the SVN_ERR() macro. */
#ifdef SVN_DEBUG
#define SVN_ERR__TRACING
#endif
/** the best kind of (@c svn_error_t *) ! */
#define SVN_NO_ERROR 0
/* The actual error codes are kept in a separate file; see comments
there for the reasons why. */
#include "svn_error_codes.h"
/** Put an English description of @a statcode into @a buf and return @a buf,
* NULL-terminated. @a statcode is either an svn error or apr error.
*/
char *
svn_strerror(apr_status_t statcode,
char *buf,
apr_size_t bufsize);
/** If @a err has a custom error message, return that, otherwise
* store the generic error string associated with @a err->apr_err into
* @a buf (terminating with NULL) and return @a buf.
*
* @since New in 1.4.
*
* @note @a buf and @a bufsize are provided in the interface so that
* this function is thread-safe and yet does no allocation.
*/
const char *svn_err_best_message(svn_error_t *err,
char *buf,
apr_size_t bufsize);
/** SVN error creation and destruction.
*
* @defgroup svn_error_error_creation_destroy Error creation and destruction
* @{
*/
/** Create a nested exception structure.
*
* Input: an APR or SVN custom error code,
* a "child" error to wrap,
* a specific message
*
* Returns: a new error structure (containing the old one).
*
* @note Errors are always allocated in a subpool of the global pool,
* since an error's lifetime is generally not related to the
* lifetime of any convenient pool. Errors must be freed
* with svn_error_clear(). The specific message should be @c NULL
* if there is nothing to add to the general message associated
* with the error code.
*
* If creating the "bottommost" error in a chain, pass @c NULL for
* the child argument.
*/
svn_error_t *
svn_error_create(apr_status_t apr_err,
svn_error_t *child,
const char *message);
/** Create an error structure with the given @a apr_err and @a child,
* with a printf-style error message produced by passing @a fmt, using
* apr_psprintf().
*/
svn_error_t *
svn_error_createf(apr_status_t apr_err,
svn_error_t *child,
const char *fmt,
...)
__attribute__ ((format(printf, 3, 4)));
/** Wrap a @a status from an APR function. If @a fmt is NULL, this is
* equivalent to svn_error_create(status,NULL,NULL). Otherwise,
* the error message is constructed by formatting @a fmt and the
* following arguments according to apr_psprintf(), and then
* appending ": " and the error message corresponding to @a status.
* (If UTF-8 translation of the APR error message fails, the ": " and
* APR error are not appended to the error message.)
*/
svn_error_t *
svn_error_wrap_apr(apr_status_t status,
const char *fmt,
...)
__attribute__((format(printf, 2, 3)));
/** A quick n' easy way to create a wrapped exception with your own
* message, before throwing it up the stack. (It uses all of the
* @a child's fields.)
*/
svn_error_t *
svn_error_quick_wrap(svn_error_t *child,
const char *new_msg);
/** Compose two errors, returning the composition as a brand new error
* and consuming the original errors. Either or both of @a err1 and
* @a err2 may be @c SVN_NO_ERROR. If both are not @c SVN_NO_ERROR,
* @a err2 will follow @a err1 in the chain of the returned error.
*
* Either @a err1 or @a err2 can be functions that return svn_error_t*
* but if both are functions they can be evaluated in either order as
* per the C language rules.
*
* @since New in 1.6.
*/
svn_error_t *
svn_error_compose_create(svn_error_t *err1,
svn_error_t *err2);
/** Add @a new_err to the end of @a chain's chain of errors. The @a new_err
* chain will be copied into @a chain's pool and destroyed, so @a new_err
* itself becomes invalid after this function.
*
* Either @a chain or @a new_err can be functions that return svn_error_t*
* but if both are functions they can be evaluated in either order as
* per the C language rules.
*/
void
svn_error_compose(svn_error_t *chain,
svn_error_t *new_err);
/** Return the root cause of @a err by finding the last error in its
* chain (e.g. it or its children). @a err may be @c SVN_NO_ERROR, in
* which case @c SVN_NO_ERROR is returned.
*
* @since New in 1.5.
*/
svn_error_t *
svn_error_root_cause(svn_error_t *err);
/** Return the first error in @a err's chain that has an error code @a
* apr_err or #SVN_NO_ERROR if there is no error with that code. The
* returned error should @em not be cleared as it shares memory with @a err.
*
* If @a err is #SVN_NO_ERROR, return #SVN_NO_ERROR.
*
* @since New in 1.7.
*/
svn_error_t *
svn_error_find_cause(svn_error_t *err, apr_status_t apr_err);
/** Create a new error that is a deep copy of @a err and return it.
*
* @since New in 1.2.
*/
svn_error_t *
svn_error_dup(svn_error_t *err);
/** Free the memory used by @a error, as well as all ancestors and
* descendants of @a error.
*
* Unlike other Subversion objects, errors are managed explicitly; you
* MUST clear an error if you are ignoring it, or you are leaking memory.
* For convenience, @a error may be @c NULL, in which case this function does
* nothing; thus, svn_error_clear(svn_foo(...)) works as an idiom to
* ignore errors.
*/
void
svn_error_clear(svn_error_t *error);
#if defined(SVN_DEBUG)
/** Set the error location for debug mode. */
void
svn_error__locate(const char *file,
long line);
/* Wrapper macros to collect file and line information */
#define svn_error_create \
(svn_error__locate(__FILE__,__LINE__), (svn_error_create))
#define svn_error_createf \
(svn_error__locate(__FILE__,__LINE__), (svn_error_createf))
#define svn_error_wrap_apr \
(svn_error__locate(__FILE__,__LINE__), (svn_error_wrap_apr))
#define svn_error_quick_wrap \
(svn_error__locate(__FILE__,__LINE__), (svn_error_quick_wrap))
#endif
/**
* Very basic default error handler: print out error stack @a error to the
* stdio stream @a stream, with each error prefixed by @a prefix; quit and
* clear @a error iff the @a fatal flag is set. Allocations are performed
* in the @a error's pool.
*
* If you're not sure what prefix to pass, just pass "svn: ". That's
* what code that used to call svn_handle_error() and now calls
* svn_handle_error2() does.
*
* @since New in 1.2.
*/
void
svn_handle_error2(svn_error_t *error,
FILE *stream,
svn_boolean_t fatal,
const char *prefix);
/** Like svn_handle_error2() but with @c prefix set to "svn: "
*
* @deprecated Provided for backward compatibility with the 1.1 API.
*/
SVN_DEPRECATED
void
svn_handle_error(svn_error_t *error,
FILE *stream,
svn_boolean_t fatal);
/**
* Very basic default warning handler: print out the error @a error to the
* stdio stream @a stream, prefixed by @a prefix. Allocations are
* performed in the error's pool.
*
* @a error may not be @c NULL.
*
* @since New in 1.2.
*/
void
svn_handle_warning2(FILE *stream,
svn_error_t *error,
const char *prefix);
/** Like svn_handle_warning2() but with @c prefix set to "svn: "
*
* @deprecated Provided for backward compatibility with the 1.1 API.
*/
SVN_DEPRECATED
void
svn_handle_warning(FILE *stream,
svn_error_t *error);
/** A statement macro for checking error values.
*
* Evaluate @a expr. If it yields an error, return that error from the
* current function. Otherwise, continue.
*
* The <tt>do { ... } while (0)</tt> wrapper has no semantic effect,
* but it makes this macro syntactically equivalent to the expression
* statement it resembles. Without it, statements like
*
* @code
* if (a)
* SVN_ERR(some operation);
* else
* foo;
* @endcode
*
* would not mean what they appear to.
*/
#define SVN_ERR(expr) \
do { \
svn_error_t *svn_err__temp = (expr); \
if (svn_err__temp) \
return svn_error_trace(svn_err__temp); \
} while (0)
/**
* A macro for wrapping an error in a source-location trace message.
*
* This macro can be used when directly returning an already created
* error (when not using SVN_ERR, svn_error_create(), etc.) to ensure
* that the call stack is recorded correctly.
*
* @since New in 1.7.
*/
#ifdef SVN_ERR__TRACING
#define SVN_ERR__TRACED "traced call"
#define svn_error_trace(expr) svn_error_quick_wrap((expr), SVN_ERR__TRACED)
#else
#define svn_error_trace(expr) (expr)
#endif
/**
* Returns an error chain that is based on @a err's error chain but
* does not include any error tracing placeholders. @a err is not
* modified, except for any allocations using its pool.
*
* The returned error chain is allocated from @a err's pool and shares
* its message and source filename character arrays. The returned
* error chain should *not* be cleared because it is not a fully
* fledged error chain, only clearing @a err should be done to clear
* the returned error chain. If @a err is cleared, then the returned
* error chain is unusable.
*
* @a err can be #SVN_NO_ERROR. If @a err is not #SVN_NO_ERROR, then
* the last link in the error chain must be a non-tracing error, i.e,
* a real error.
*
* @since New in 1.7.
*/
svn_error_t *svn_error_purge_tracing(svn_error_t *err);
/** A statement macro, very similar to @c SVN_ERR.
*
* This macro will wrap the error with the specified text before
* returning the error.
*/
#define SVN_ERR_W(expr, wrap_msg) \
do { \
svn_error_t *svn_err__temp = (expr); \
if (svn_err__temp) \
return svn_error_quick_wrap(svn_err__temp, wrap_msg); \
} while (0)
/** A statement macro, similar to @c SVN_ERR, but returns an integer.
*
* Evaluate @a expr. If it yields an error, handle that error and
* return @c EXIT_FAILURE.
*/
#define SVN_INT_ERR(expr) \
do { \
svn_error_t *svn_err__temp = (expr); \
if (svn_err__temp) { \
svn_handle_error2(svn_err__temp, stderr, FALSE, "svn: "); \
svn_error_clear(svn_err__temp); \
return EXIT_FAILURE; } \
} while (0)
/** @} */
/** Error groups
*
* @defgroup svn_error_error_groups Error groups
* @{
*/
/**
* Return TRUE if @a err is an error specifically related to locking a
* path in the repository, FALSE otherwise.
*
* SVN_ERR_FS_OUT_OF_DATE and SVN_ERR_FS_NOT_FOUND are in here because it's a
* non-fatal error that can be thrown when attempting to lock an item.
*
* @since New in 1.2.
*/
#define SVN_ERR_IS_LOCK_ERROR(err) \
(err->apr_err == SVN_ERR_FS_PATH_ALREADY_LOCKED || \
err->apr_err == SVN_ERR_FS_NOT_FOUND || \
err->apr_err == SVN_ERR_FS_OUT_OF_DATE || \
err->apr_err == SVN_ERR_FS_BAD_LOCK_TOKEN)
/**
* Return TRUE if @a err is an error specifically related to unlocking
* a path in the repository, FALSE otherwise.
*
* @since New in 1.2.
*/
#define SVN_ERR_IS_UNLOCK_ERROR(err) \
(err->apr_err == SVN_ERR_FS_PATH_NOT_LOCKED || \
err->apr_err == SVN_ERR_FS_BAD_LOCK_TOKEN || \
err->apr_err == SVN_ERR_FS_LOCK_OWNER_MISMATCH || \
err->apr_err == SVN_ERR_FS_NO_SUCH_LOCK || \
err->apr_err == SVN_ERR_RA_NOT_LOCKED || \
err->apr_err == SVN_ERR_FS_LOCK_EXPIRED)
/** Evaluates to @c TRUE iff @a apr_err (of type #apr_status_t) is in the given
* @a category, which should be one of the @c SVN_ERR_*_CATEGORY_START
* constants.
*
* @since New in 1.7.
*/
#define SVN_ERROR_IN_CATEGORY(apr_err, category) \
((category) == ((apr_err) / SVN_ERR_CATEGORY_SIZE) * SVN_ERR_CATEGORY_SIZE)
/** @} */
/** Internal malfunctions and assertions
*
* @defgroup svn_error_malfunction_assertion Malfunctions and assertions
* @{
*/
/** Report that an internal malfunction has occurred, and possibly terminate
* the program.
*
* Act as determined by the current "malfunction handler" which may have
* been specified by a call to svn_error_set_malfunction_handler() or else
* is the default handler as specified in that function's documentation. If
* the malfunction handler returns, then cause the function using this macro
* to return the error object that it generated.
*
* @note The intended use of this macro is where execution reaches a point
* that cannot possibly be reached unless there is a bug in the program.
*
* @since New in 1.6.
*/
#define SVN_ERR_MALFUNCTION() \
do { \
return svn_error_trace(svn_error__malfunction( \
TRUE, __FILE__, __LINE__, NULL)); \
} while (0)
/** Similar to SVN_ERR_MALFUNCTION(), but without the option of returning
* an error to the calling function.
*
* If possible you should use SVN_ERR_MALFUNCTION() instead.
*
* @since New in 1.6.
*/
#define SVN_ERR_MALFUNCTION_NO_RETURN() \
do { \
svn_error__malfunction(FALSE, __FILE__, __LINE__, NULL); \
abort(); \
} while (1)
/** Check that a condition is true: if not, report an error and possibly
* terminate the program.
*
* If the Boolean expression @a expr is true, do nothing. Otherwise,
* act as determined by the current "malfunction handler" which may have
* been specified by a call to svn_error_set_malfunction_handler() or else
* is the default handler as specified in that function's documentation. If
* the malfunction handler returns, then cause the function using this macro
* to return the error object that it generated.
*
* @note The intended use of this macro is to check a condition that cannot
* possibly be false unless there is a bug in the program.
*
* @note The condition to be checked should not be computationally expensive
* if it is reached often, as, unlike traditional "assert" statements, the
* evaluation of this expression is not compiled out in release-mode builds.
*
* @since New in 1.6.
*/
#define SVN_ERR_ASSERT(expr) \
do { \
if (!(expr)) \
SVN_ERR(svn_error__malfunction(TRUE, __FILE__, __LINE__, #expr)); \
} while (0)
/** Similar to SVN_ERR_ASSERT(), but without the option of returning
* an error to the calling function.
*
* If possible you should use SVN_ERR_ASSERT() instead.
*
* @since New in 1.6.
*/
#define SVN_ERR_ASSERT_NO_RETURN(expr) \
do { \
if (!(expr)) { \
svn_error__malfunction(FALSE, __FILE__, __LINE__, #expr); \
abort(); \
} \
} while (0)
/** Report a "Not implemented" malfunction. Internal use only. */
#define SVN__NOT_IMPLEMENTED() \
return svn_error__malfunction(TRUE, __FILE__, __LINE__, "Not implemented.")
/** A helper function for the macros that report malfunctions. Handle a
* malfunction by calling the current "malfunction handler" which may have
* been specified by a call to svn_error_set_malfunction_handler() or else
* is the default handler as specified in that function's documentation.
*
* Pass all of the parameters to the handler. The error occurred in the
* source file @a file at line @a line, and was an assertion failure of the
* expression @a expr, or, if @a expr is null, an unconditional error.
*
* If @a can_return is true, the handler can return an error object
* that is returned by the caller. If @a can_return is false the
* method should never return. (The caller will call abort())
*
* @since New in 1.6.
*/
svn_error_t *
svn_error__malfunction(svn_boolean_t can_return,
const char *file,
int line,
const char *expr);
/** A type of function that handles an assertion failure or other internal
* malfunction detected within the Subversion libraries.
*
* The error occurred in the source file @a file at line @a line, and was an
* assertion failure of the expression @a expr, or, if @a expr is null, an
* unconditional error.
*
* If @a can_return is false a function of this type must never return.
*
* If @a can_return is true a function of this type must do one of:
* - Return an error object describing the error, using an error code in
* the category SVN_ERR_MALFUNC_CATEGORY_START.
* - Never return.
*
* The function may alter its behaviour according to compile-time
* and run-time and even interactive conditions.
*
* @see SVN_ERROR_IN_CATEGORY()
*
* @since New in 1.6.
*/
typedef svn_error_t *(*svn_error_malfunction_handler_t)
(svn_boolean_t can_return, const char *file, int line, const char *expr);
/** Cause subsequent malfunctions to be handled by @a func.
* Return the handler that was previously in effect.
*
* @a func may not be null.
*
* @note The default handler is svn_error_abort_on_malfunction().
*
* @note This function must be called in a single-threaded context.
*
* @since New in 1.6.
*/
svn_error_malfunction_handler_t
svn_error_set_malfunction_handler(svn_error_malfunction_handler_t func);
/** Handle a malfunction by returning an error object that describes it.
*
* When @a can_return is false, abort()
*
* This function implements @c svn_error_malfunction_handler_t.
*
* @since New in 1.6.
*/
svn_error_t *
svn_error_raise_on_malfunction(svn_boolean_t can_return,
const char *file,
int line,
const char *expr);
/** Handle a malfunction by printing a message to stderr and aborting.
*
* This function implements @c svn_error_malfunction_handler_t.
*
* @since New in 1.6.
*/
svn_error_t *
svn_error_abort_on_malfunction(svn_boolean_t can_return,
const char *file,
int line,
const char *expr);
/** @} */
#ifdef __cplusplus
}
#endif /* __cplusplus */
#endif /* SVN_ERROR_H */