Check whether the current system is sensitive to -Ddefines making off_t having different types/sizes. Automatically define a config.h symbol LARGEFILE_SENSITIVE if that is the case, otherwise leave everything as is.
This macro builds on top of AC_SYS_LARGEFILE to detect whether special options are neede to make the code use 64bit off_t - in many setups this will also make the code use 64bit off_t immediatly.
The common use of a LARGEFILE_SENSITIVE config.h-define is to rename exported functions, usually adding a 64 to the original function name. Such renamings are only needed on systems being both (a) 32bit off_t by default and (b) implementing large.file extensions (as for unix98).
a renaming section could look like this:
#if defined LARGEFILE_SENSITIVE && _FILE_OFFSET_BITS+0 == 64 #define zzip_open zzip_open64 #define zzip_seek zzip_seek64 #endif
for libraries, it is best to take advantage of the prefix-config.h macro, otherwise you want to export a renamed LARGEFILE_SENSITIVE in an installed header file. -> see AX_PREFIX_CONFIG_H
Download the latest version of ax_sys_largefile_sensitive.m4 or browse the macro’s revision history.
Copyright © 2008 Guido U. Draheim email@example.com
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