/* -*- mode: C -*- */ /* IGraph library. Copyright (C) 2003-2012 Gabor Csardi 334 Harvard street, Cambridge, MA 02139 USA This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #ifndef IGRAPH_ERROR_H #define IGRAPH_ERROR_H #include #include "igraph_decls.h" __BEGIN_DECLS /* This file contains the igraph error handling. * Most bits are taken literally from the GSL library (with the GSL_ * prefix renamed to IGRAPH_), as I couldn't find a better way to do * them. */ /** * \section errorhandlingbasics Error handling basics * * \a igraph functions can run into various problems preventing them * from normal operation. The user might have supplied invalid arguments, * e.g. a non-square matrix when a square-matrix was expected, or the program * has run out of memory while some more memory allocation is required, etc. * * * By default \a igraph aborts the program when it runs into an * error. While this behavior might be good enough for smaller programs, * it is without doubt avoidable in larger projects. Please read further * if your project requires more sophisticated error handling. You can * safely skip the rest of this chapter otherwise. * */ /** * \section errorhandlers Error handlers * * * If \a igraph runs into an error - an invalid argument was supplied * to a function, or we've ran out of memory - the control is * transferred to the \emb error handler \eme function. * * The default error handler is \ref igraph_error_handler_abort which * prints an error message and aborts the program. * * * The \ref igraph_set_error_handler() function can be used to set a new * error handler function of type \ref igraph_error_handler_t; see the * documentation of this type for details. * * * There are two other predefined error handler functions, * \ref igraph_error_handler_ignore and \ref igraph_error_handler_printignore. * These deallocate the temporarily allocated memory (more about this * later) and return with the error code. The latter also prints an * error message. If you use these error handlers you need to take * care about possible errors yourself by checking the return value of * (almost) every non-void \a igraph function. * * Independently of the error handler installed, all functions in the * library do their best to leave their arguments * \em semantically unchanged if an error * happens. By semantically we mean that the implementation of an * object supplied as an argument might change, but its * \quote meaning \endquote in most cases does not. The rare occasions * when this rule is violated are documented in this manual. * */ /** * \section errorcodes Error codes * * Every \a igraph function which can fail return a * single integer error code. Some functions are very simple and * cannot run into any error, these may return other types, or * \type void as well. The error codes are defined by the * \ref igraph_error_type_t enumeration. * */ /** * \section writing_error_handlers Writing error handlers * * * The contents of the rest of this chapter might be useful only * for those who want to create an interface to \a igraph from another * language. Most readers can safely skip to the next chapter. * * * * You can write and install error handlers simply by defining a * function of type \ref igraph_error_handler_t and calling * \ref igraph_set_error_handler(). This feature is useful for interface * writers, as \a igraph will have the chance to * signal errors the appropriate way, eg. the R interface defines an * error handler which calls the error() * function, as required by R, while the Python interface has an error * handler which raises an exception according to the Python way. * * * If you want to write an error handler, your error handler should * call \ref IGRAPH_FINALLY_FREE() to deallocate all temporary memory to * prevent memory leaks. * */ /** * \section error_handling_internals Error handling internals * * * If an error happens, the functions in the library call the * \ref IGRAPH_ERROR macro with a textual description of the error and an * \a igraph error code. This macro calls (through the \ref * igraph_error() function) the installed error handler. Another useful * macro is \ref IGRAPH_CHECK(). This checks the return value of its * argument, which is normally a function call, and calls \ref * IGRAPH_ERROR if it is not \c IGRAPH_SUCCESS. * */ /** * \section deallocating_memory Deallocating memory * * * If a function runs into an error (and the program is not aborted) * the error handler should deallocate all temporary memory. This is * done by storing the address and the destroy function of all temporary * objects in a stack. The \ref IGRAPH_FINALLY function declares an object as * temporary by placing its address in the stack. If an \a igraph function returns * with success it calls \ref IGRAPH_FINALLY_CLEAN() with the * number of objects to remove from the stack. If an error happens * however, the error handler should call \ref IGRAPH_FINALLY_FREE() to * deallocate each object added to the stack. This means that the * temporary objects allocated in the calling function (and etc.) will * be freed as well. * */ /** * \section writing_functions_error_handling Writing \a igraph functions with * proper error handling * * * There are some simple rules to keep in order to have functions * behaving well in erroneous situations. First, check the arguments * of the functions and call \ref IGRAPH_ERROR if they are invalid. Second, * call \ref IGRAPH_FINALLY on each dynamically allocated object and call * \ref IGRAPH_FINALLY_CLEAN() with the proper argument before returning. Third, use * \ref IGRAPH_CHECK on all \a igraph function calls which can generate errors. * * * The size of the stack used for this bookkeeping is fixed, and * small. If you want to allocate several objects, write a destroy * function which can deallocate all of these. See the * adjlist.c file in the * \a igraph source for an example. * * * For some functions these mechanisms are simply not flexible * enough. These functions should define their own error handlers and * restore the error handler before they return. * */ /** * \section error_handling_threads Error handling and threads * * * It is likely that the \a igraph error handling * method is \em not thread-safe, mainly because of * the static global stack which is used to store the address of the * temporarily allocated objects. This issue might be addressed in a * later version of \a igraph. * */ /** * \typedef igraph_error_handler_t * \brief Type of error handler functions. * * This is the type of the error handler functions. * \param reason Textual description of the error. * \param file The source file in which the error is noticed. * \param line The number of the line in the source file which triggered * the error * \param igraph_errno The \a igraph error code. */ typedef void igraph_error_handler_t (const char * reason, const char * file, int line, int igraph_errno); /** * \var igraph_error_handler_abort * \brief Abort program in case of error. * * The default error handler, prints an error message and aborts the * program. */ extern igraph_error_handler_t igraph_error_handler_abort; /** * \var igraph_error_handler_ignore * \brief Ignore errors. * * This error handler frees the temporarily allocated memory and returns * with the error code. */ extern igraph_error_handler_t igraph_error_handler_ignore; /** * \var igraph_error_handler_printignore * \brief Print and ignore errors. * * Frees temporarily allocated memory, prints an error message to the * standard error and returns with the error code. */ extern igraph_error_handler_t igraph_error_handler_printignore; /** * \function igraph_set_error_handler * \brief Set a new error handler. * * Installs a new error handler. If called with 0, it installs the * default error handler (which is currently * \ref igraph_error_handler_abort). * \param new_handler The error handler function to install. * \return The old error handler function. This should be saved and * restored if \p new_handler is not needed any * more. */ DECLDIR igraph_error_handler_t* igraph_set_error_handler(igraph_error_handler_t* new_handler); /** * \typedef igraph_error_type_t * \brief Error code type. * These are the possible values returned by \a igraph functions. * Note that these are interesting only if you defined an error handler * with \ref igraph_set_error_handler(). Otherwise the program is aborted * and the function causing the error never returns. * * \enumval IGRAPH_SUCCESS The function successfully completed its task. * \enumval IGRAPH_FAILURE Something went wrong. You'll almost never * meet this error as normally more specific error codes are used. * \enumval IGRAPH_ENOMEM There wasn't enough memory to allocate * on the heap. * \enumval IGRAPH_PARSEERROR A parse error was found in a file. * \enumval IGRAPH_EINVAL A parameter's value is invalid. Eg. negative * number was specified as the number of vertices. * \enumval IGRAPH_EXISTS A graph/vertex/edge attribute is already * installed with the given name. * \enumval IGRAPH_EINVEVECTOR Invalid vector of vertex ids. A vertex id * is either negative or bigger than the number of vertices minus one. * \enumval IGRAPH_EINVVID Invalid vertex id, negative or too big. * \enumval IGRAPH_NONSQUARE A non-square matrix was received while a * square matrix was expected. * \enumval IGRAPH_EINVMODE Invalid mode parameter. * \enumval IGRAPH_EFILE A file operation failed. Eg. a file doesn't exist, * or the user has no rights to open it. * \enumval IGRAPH_UNIMPLEMENTED Attempted to call an unimplemented or * disabled (at compile-time) function. * \enumval IGRAPH_DIVERGED A numeric algorithm failed to converge. * \enumval IGRAPH_ARPACK_PROD Matrix-vector product failed. * \enumval IGRAPH_ARPACK_NPOS N must be positive. * \enumval IGRAPH_ARPACK_NEVNPOS NEV must be positive. * \enumval IGRAPH_ARPACK_NCVSMALL NCV must be bigger. * \enumval IGRAPH_ARPACK_NONPOSI Maximum number of iterations should be positive. * \enumval IGRAPH_ARPACK_WHICHINV Invalid WHICH parameter. * \enumval IGRAPH_ARPACK_BMATINV Invalid BMAT parameter. * \enumval IGRAPH_ARPACK_WORKLSMALL WORKL is too small. * \enumval IGRAPH_ARPACK_TRIDERR LAPACK error in tridiagonal eigenvalue calculation. * \enumval IGRAPH_ARPACK_ZEROSTART Starting vector is zero. * \enumval IGRAPH_ARPACK_MODEINV MODE is invalid. * \enumval IGRAPH_ARPACK_MODEBMAT MODE and BMAT are not compatible. * \enumval IGRAPH_ARPACK_ISHIFT ISHIFT must be 0 or 1. * \enumval IGRAPH_ARPACK_NEVBE NEV and WHICH='BE' are incompatible. * \enumval IGRAPH_ARPACK_NOFACT Could not build an Arnoldi factorization. * \enumval IGRAPH_ARPACK_FAILED No eigenvalues to sufficient accuracy. * \enumval IGRAPH_ARPACK_HOWMNY HOWMNY is invalid. * \enumval IGRAPH_ARPACK_HOWMNYS HOWMNY='S' is not implemented. * \enumval IGRAPH_ARPACK_EVDIFF Different number of converged Ritz values. * \enumval IGRAPH_ARPACK_SHUR Error from calculation of a real Schur form. * \enumval IGRAPH_ARPACK_LAPACK LAPACK (dtrevc) error for calculating eigenvectors. * \enumval IGRAPH_ARPACK_UNKNOWN Unknown ARPACK error. * \enumval IGRAPH_ENEGLOOP Negative loop detected while calculating shortest paths. * \enumval IGRAPH_EINTERNAL Internal error, likely a bug in igraph. * \enumval IGRAPH_EDIVZERO Big integer division by zero. * \enumval IGARPH_GLP_EBOUND GLPK error (GLP_EBOUND). * \enumval IGARPH_GLP_EROOT GLPK error (GLP_EROOT). * \enumval IGARPH_GLP_ENOPFS GLPK error (GLP_ENOPFS). * \enumval IGARPH_GLP_ENODFS GLPK error (GLP_ENODFS). * \enumval IGARPH_GLP_EFAIL GLPK error (GLP_EFAIL). * \enumval IGARPH_GLP_EMIPGAP GLPK error (GLP_EMIPGAP). * \enumval IGARPH_GLP_ETMLIM GLPK error (GLP_ETMLIM). * \enumval IGARPH_GLP_ESTOP GLPK error (GLP_ESTOP). * \enumval IGRAPH_EATTRIBUTES Attribute handler error. The user is not * expected to find this; it is signalled if some igraph function is * not using the attribute handler interface properly. * \enumval IGRAPH_EATTRCOMBINE Unimplemented attribute combination * method for the given attribute type. * \enumval IGRAPH_ELAPACK A LAPACK call resulted an error. * \enumval IGRAPH_EDRL Internal error in the DrL layout generator. * \enumval IGRAPH_EOVERFLOW Integer or double overflow. * \enumval IGRAPH_EGLP Internal GLPK error. * \enumval IGRAPH_CPUTIME CPU time exceeded. * \enumval IGRAPH_EUNDERFLOW Integer or double underflow. * \enumval IGRAPH_ERWSTUCK Random walk got stuck. */ /* Each enum value below must have a corresponding error string in * igraph_i_error_strings[] in igraph_error.c */ typedef enum { IGRAPH_SUCCESS = 0, IGRAPH_FAILURE = 1, IGRAPH_ENOMEM = 2, IGRAPH_PARSEERROR = 3, IGRAPH_EINVAL = 4, IGRAPH_EXISTS = 5, IGRAPH_EINVEVECTOR = 6, IGRAPH_EINVVID = 7, IGRAPH_NONSQUARE = 8, IGRAPH_EINVMODE = 9, IGRAPH_EFILE = 10, IGRAPH_UNIMPLEMENTED = 12, IGRAPH_INTERRUPTED = 13, IGRAPH_DIVERGED = 14, IGRAPH_ARPACK_PROD = 15, IGRAPH_ARPACK_NPOS = 16, IGRAPH_ARPACK_NEVNPOS = 17, IGRAPH_ARPACK_NCVSMALL = 18, IGRAPH_ARPACK_NONPOSI = 19, IGRAPH_ARPACK_WHICHINV = 20, IGRAPH_ARPACK_BMATINV = 21, IGRAPH_ARPACK_WORKLSMALL = 22, IGRAPH_ARPACK_TRIDERR = 23, IGRAPH_ARPACK_ZEROSTART = 24, IGRAPH_ARPACK_MODEINV = 25, IGRAPH_ARPACK_MODEBMAT = 26, IGRAPH_ARPACK_ISHIFT = 27, IGRAPH_ARPACK_NEVBE = 28, IGRAPH_ARPACK_NOFACT = 29, IGRAPH_ARPACK_FAILED = 30, IGRAPH_ARPACK_HOWMNY = 31, IGRAPH_ARPACK_HOWMNYS = 32, IGRAPH_ARPACK_EVDIFF = 33, IGRAPH_ARPACK_SHUR = 34, IGRAPH_ARPACK_LAPACK = 35, IGRAPH_ARPACK_UNKNOWN = 36, IGRAPH_ENEGLOOP = 37, IGRAPH_EINTERNAL = 38, IGRAPH_ARPACK_MAXIT = 39, IGRAPH_ARPACK_NOSHIFT = 40, IGRAPH_ARPACK_REORDER = 41, IGRAPH_EDIVZERO = 42, IGRAPH_GLP_EBOUND = 43, IGRAPH_GLP_EROOT = 44, IGRAPH_GLP_ENOPFS = 45, IGRAPH_GLP_ENODFS = 46, IGRAPH_GLP_EFAIL = 47, IGRAPH_GLP_EMIPGAP = 48, IGRAPH_GLP_ETMLIM = 49, IGRAPH_GLP_ESTOP = 50, IGRAPH_EATTRIBUTES = 51, IGRAPH_EATTRCOMBINE = 52, IGRAPH_ELAPACK = 53, IGRAPH_EDRL = 54, IGRAPH_EOVERFLOW = 55, IGRAPH_EGLP = 56, IGRAPH_CPUTIME = 57, IGRAPH_EUNDERFLOW = 58, IGRAPH_ERWSTUCK = 59, IGRAPH_STOP = 60, /* undocumented, used internally; signals a request to stop in functions like igraph_i_maximal_cliques_bk */ } igraph_error_type_t; /** * \define IGRAPH_ERROR * \brief Trigger an error. * * \a igraph functions usually use this macro when they notice an error. * It calls * \ref igraph_error() with the proper parameters and if that returns * the macro returns the "calling" function as well, with the error * code. If for some (suspicious) reason you want to call the error * handler without returning from the current function, call * \ref igraph_error() directly. * \param reason Textual description of the error. This should be * something more descriptive than the text associated with the error * code. Eg. if the error code is \c IGRAPH_EINVAL, * its associated text (see \ref igraph_strerror()) is "Invalid * value" and this string should explain which parameter was invalid * and maybe why. * \param igraph_errno The \a igraph error code. */ #define IGRAPH_ERROR(reason,igraph_errno) \ do { \ igraph_error (reason, __FILE__, __LINE__, igraph_errno) ; \ return igraph_errno ; \ } while (0) /** * \function igraph_error * \brief Trigger an error. * * \a igraph functions usually call this function (most often via the * \ref IGRAPH_ERROR macro) if they notice an error. * It calls the currently installed error handler function with the * supplied arguments. * * \param reason Textual description of the error. * \param file The source file in which the error was noticed. * \param line The number of line in the source file which triggered the * error. * \param igraph_errno The \a igraph error code. * \return the error code (if it returns) * * \sa igraph_errorf(). */ DECLDIR int igraph_error(const char *reason, const char *file, int line, int igraph_errno); /** * \function igraph_errorf * \brief Trigger an error, printf-like version. * * \param reason Textual description of the error, interpreted as * a printf format string. * \param file The source file in which the error was noticed. * \param line The line in the source file which triggered the error. * \param igraph_errno The \a igraph error code. * \param ... Additional parameters, the values to substitute into the * format string. * * \sa igraph_error(). */ DECLDIR int igraph_errorf(const char *reason, const char *file, int line, int igraph_errno, ...); DECLDIR int igraph_errorvf(const char *reason, const char *file, int line, int igraph_errno, va_list ap); /** * \function igraph_strerror * \brief Textual description of an error. * * This is a simple utility function, it gives a short general textual * description for an \a igraph error code. * * \param igraph_errno The \a igraph error code. * \return pointer to the textual description of the error code. */ DECLDIR const char* igraph_strerror(const int igraph_errno); #define IGRAPH_ERROR_SELECT_2(a,b) ((a) != IGRAPH_SUCCESS ? (a) : ((b) != IGRAPH_SUCCESS ? (b) : IGRAPH_SUCCESS)) #define IGRAPH_ERROR_SELECT_3(a,b,c) ((a) != IGRAPH_SUCCESS ? (a) : IGRAPH_ERROR_SELECT_2(b,c)) #define IGRAPH_ERROR_SELECT_4(a,b,c,d) ((a) != IGRAPH_SUCCESS ? (a) : IGRAPH_ERROR_SELECT_3(b,c,d)) #define IGRAPH_ERROR_SELECT_5(a,b,c,d,e) ((a) != IGRAPH_SUCCESS ? (a) : IGRAPH_ERROR_SELECT_4(b,c,d,e)) /* Now comes the more convenient error handling macro arsenal. * Ideas taken from exception.{h,c} by Laurent Deniau see * http://cern.ch/Laurent.Deniau/html/oopc/oopc.html#Exceptions for more * information. We don't use the exception handling code though. */ struct igraph_i_protectedPtr { int all; void *ptr; void (*func)(void*); }; typedef void igraph_finally_func_t (void*); DECLDIR void IGRAPH_FINALLY_REAL(void (*func)(void*), void* ptr); /** * \function IGRAPH_FINALLY_CLEAN * \brief Signal clean deallocation of objects. * * Removes the specified number of objects from the stack of * temporarily allocated objects. Most often this is called just * before returning from a function. * \param num The number of objects to remove from the bookkeeping * stack. */ DECLDIR void IGRAPH_FINALLY_CLEAN(int num); /** * \function IGRAPH_FINALLY_FREE * \brief Deallocate all registered objects. * * Calls the destroy function for all objects in the stack of * temporarily allocated objects. This is usually called only from an * error handler. It is \em not appropriate to use it * instead of destroying each unneeded object of a function, as it * destroys the temporary objects of the caller function (and so on) * as well. */ DECLDIR void IGRAPH_FINALLY_FREE(void); /** * \function IGRAPH_FINALLY_STACK_SIZE * \brief Returns the number of registered objects. * * Returns the number of objects in the stack of temporarily allocated * objects. This function is handy if you write an own igraph routine and * you want to make sure it handles errors properly. A properly written * igraph routine should not leave pointers to temporarily allocated objects * in the finally stack, because otherwise an \ref IGRAPH_FINALLY_FREE call * in another igraph function would result in freeing these objects as well * (and this is really hard to debug, since the error will be not in that * function that shows erroneous behaviour). Therefore, it is advised to * write your own test cases and examine \ref IGRAPH_FINALLY_STACK_SIZE * before and after your test cases - the numbers should be equal. */ DECLDIR int IGRAPH_FINALLY_STACK_SIZE(void); /** * \define IGRAPH_FINALLY_STACK_EMPTY * \brief Returns true if there are no registered objects, false otherwise. * * This is just a shorthand notation for checking that * \ref IGRAPH_FINALLY_STACK_SIZE is zero. */ #define IGRAPH_FINALLY_STACK_EMPTY (IGRAPH_FINALLY_STACK_SIZE() == 0) /** * \define IGRAPH_FINALLY * \brief Register an object for deallocation. * \param func The address of the function which is normally called to * destroy the object. * \param ptr Pointer to the object itself. * * This macro places the address of an object, together with the * address of its destructor in a stack. This stack is used if an * error happens to deallocate temporarily allocated objects to * prevent memory leaks. */ #define IGRAPH_FINALLY(func,ptr) \ IGRAPH_FINALLY_REAL((igraph_finally_func_t*)(func), (ptr)) #if !defined(GCC_VERSION_MAJOR) && defined(__GNUC__) #define GCC_VERSION_MAJOR __GNUC__ #endif #if defined(GCC_VERSION_MAJOR) && (GCC_VERSION_MAJOR >= 3) #define IGRAPH_UNLIKELY(a) __builtin_expect((a), 0) #define IGRAPH_LIKELY(a) __builtin_expect((a), 1) #else #define IGRAPH_UNLIKELY(a) a #define IGRAPH_LIKELY(a) a #endif /** * \define IGRAPH_CHECK * \brief Check the return value of a function call. * * \param a An expression, usually a function call. * * Executes the expression and checks its value. If this is not * \c IGRAPH_SUCCESS, it calls \ref IGRAPH_ERROR with * the value as the error code. Here is an example usage: * \verbatim IGRAPH_CHECK(vector_push_back(&v, 100)); \endverbatim * * There is only one reason to use this macro when writing * \a igraph functions. If the user installs an error handler which * returns to the auxiliary calling code (like \ref * igraph_error_handler_ignore and \ref * igraph_error_handler_printignore), and the \a igraph function * signalling the error is called from another \a igraph function * then we need to make sure that the error is propagated back to * the auxiliary (ie. non-igraph) calling function. This is achieved * by using IGRAPH_CHECK on every \a igraph * call which can return an error code. */ #define IGRAPH_CHECK(a) do { \ int igraph_i_ret=(a); \ if (IGRAPH_UNLIKELY(igraph_i_ret != 0)) {\ IGRAPH_ERROR("", igraph_i_ret); \ } } while (0) /** * \section about_igraph_warnings Warning messages * * * Igraph also supports warning messages in addition to error * messages. Warning messages typically do not terminate the * program, but they are usually crucial to the user. * * * * Igraph warning are handled similarly to errors. There is a * separate warning handler function that is called whenever * an igraph function triggers a warning. This handler can be * set by the \ref igraph_set_warning_handler() function. There are * two predefined simple warning handlers, * \ref igraph_warning_handler_ignore() and * \ref igraph_warning_handler_print(), the latter being the default. * * * * To trigger a warning, igraph functions typically use the * \ref IGRAPH_WARNING() macro, the \ref igraph_warning() function, * or if more flexibility is needed, \ref igraph_warningf(). * */ /** * \typedef igraph_warning_handler_t * Type of igraph warning handler functions * * Currently it is defined to have the same type as * \ref igraph_error_handler_t, although the last (error code) * argument is not used. */ typedef igraph_error_handler_t igraph_warning_handler_t; /** * \function igraph_set_warning_handler * Install a warning handler * * Install the supplied warning handler function. * \param new_handler The new warning handler function to install. * Supply a null pointer here to uninstall the current * warning handler, without installing a new one. * \return The current warning handler function. */ DECLDIR igraph_warning_handler_t* igraph_set_warning_handler(igraph_warning_handler_t* new_handler); extern igraph_warning_handler_t igraph_warning_handler_ignore; extern igraph_warning_handler_t igraph_warning_handler_print; /** * \function igraph_warning * Trigger a warning * * Call this function if you want to trigger a warning from within * a function that uses igraph. * \param reason Textual description of the warning. * \param file The source file in which the warning was noticed. * \param line The number of line in the source file which triggered the * warning. * \param igraph_errno Warnings could have potentially error codes as well, * but this is currently not used in igraph. * \return The supplied error code. */ DECLDIR int igraph_warning(const char *reason, const char *file, int line, int igraph_errno); /** * \function igraph_warningf * Trigger a warning, more flexible printf-like syntax * * This function is similar to \ref igraph_warning(), but * uses a printf-like syntax. It substitutes the additional arguments * into the \p reason template string and calls \ref igraph_warning(). * \param reason Textual description of the warning, a template string * with the same syntax as the standard printf C library function. * \param file The source file in which the warning was noticed. * \param line The number of line in the source file which triggered the * warning. * \param igraph_errno Warnings could have potentially error codes as well, * but this is currently not used in igraph. * \param ... The additional arguments to be substituted into the * template string. * \return The supplied error code. */ DECLDIR int igraph_warningf(const char *reason, const char *file, int line, int igraph_errno, ...); /** * \define IGRAPH_WARNING * Trigger a warning. * * This is the usual way of triggering a warning from an igraph * function. It calls \ref igraph_warning(). * \param reason The warning message. */ #define IGRAPH_WARNING(reason) \ do { \ igraph_warning(reason, __FILE__, __LINE__, -1); \ } while (0) __END_DECLS #endif