/* * Copyright (C) 2008 Patrick Ohly */ #ifndef ICALSTRDUP_H #define ICALSTRDUP_H #ifndef HANDLE_LIBICAL_MEMORY # define HANDLE_LIBICAL_MEMORY 1 #endif #include #ifdef __cplusplus extern "C" { #pragma } #endif /* __cplusplus */ #if !defined(LIBICAL_MEMFIXES) || defined(EVOLUTION_COMPATIBILITY) /** * The patch in http://bugzilla.gnome.org/show_bug.cgi?id=516408 * changes the ownership of strings returned by some libical and libecal * functions: previously, the memory was owned by the library. * After the patch the caller owns the copied string and must free it. * * The upstream SourceForge libical has incorporated the patch, but * without changing the semantic of the existing calls. Instead they * added _r variants which return memory that the caller must free. * As soon as Evolution switches to upstream libical (planned for 2.25), * it probably will have to bump the libecal version because the API * is reverted so that binaries which free strings will crash. * When EVOLUTION_COMPATIBILITY is defined, SyncEvolution deals with * this by always checking at runtime what the memory handling is. * * This utility function ensures that the caller *always* owns the * returned string. When compiled against a current Evolution * Dataserver, the function becomes a NOP macro, unless compatibility * mode is on (in which case the current binary might later run with * an older Evolution release!). If not a NOP macro, then the function * duplicates the string; it handles NULL by passing it through. * * When compiled against an old Evolution Dataserver, then a runtime * check can be enabled to to determine whether the string needs to be * duplicated. If uncertain, it always duplicates the string. If the * check fails, then memory is leaked, which also happens when running * programs which do not know about the patch. * * To enable the runtime check, compile the .c file with -D_GNU_SOURCE * and -DHAVE_DLFCN_H. If HAVE_CONFIG_H is set, then config.h is included * and can be set to set some of these defines. If enabled, then link with * -ldl. * * ical_strdup() must be wrapped around the following functions: * - icalreqstattype_as_string * - icalproperty_as_ical_string * - icalproperty_get_parameter_as_string * - icalproperty_get_value_as_string * - icallangbind_property_eval_string * - icalperiodtype_as_ical_string * - icaltime_as_ical_string * - icalvalue_as_ical_string * - icalcomponent_as_ical_string * - e_cal_component_get_recurid_as_string * * @param x result of one of the functions above * @return string which has to be freed by caller, may be NULL if x was NULL */ extern char *ical_strdup(const char *x); #else # define ical_strdup(_x) (_x) #endif #ifdef __cplusplus } #endif /* __cplusplus */ #endif /* ICALSTRDUP_H */