From: Eric Blake <ebl...@redhat.com> Subject: Re: [PATCH] AC_SYS_LARGEFILE: define _DARWIN_USE_64_BIT_INODE conditionally Date: Tue, 15 Jan 2013 20:07:03 -0700
> On 01/15/2013 05:01 PM, PHO wrote: >> * lib/autoconf/specific.m4 (AC_SYS_LARGEFILE): This macro was >> accidentally defining _DARWIN_USE_64_BIT_INODE with AH_VERBATIM so the >> variable was defined even when $enable_largefile = no. The bug also >> caused inconsistency between AH_HEADER and confdefs.h thus >> AC_COMPUTE_INT(VAR, [sizeof(ino_t)]) produced a wrong result, >> i.e. 32-bit ino_t for configuration time and 64-bit ino_t for >> build/run time. >> --- > > Thanks for the report. but I don't think this patch is quite right. Can > you please provide more details, such as a minimal configure.ac to > provoke the issue, and the resulting config.h that gets generated > incorrectly? OK, here's a set of files to reproduce the problem: - configure.ac https://gist.github.com/4547173#file-configure-ac - main.c https://gist.github.com/4547173#file-main-c - generated config.h.in https://gist.github.com/4547173#file-config-h-in - generated config.h https://gist.github.com/4547173#file-config-h - the output https://gist.github.com/4547173#file-log Expected output of ./main: SIZEOF_INO_T in config.h: 8 sizeof(ino_t) in actuality: 8 >> [/* Enable large inode numbers on Mac OS X 10.5. */ >> #ifndef _DARWIN_USE_64_BIT_INODE >> -# define _DARWIN_USE_64_BIT_INODE 1 >> +# undef _DARWIN_USE_64_BIT_INODE >> #endif]) > > Unconditionally undefining a macro when it is already inside an #ifndef > block is pointless. >From what I understand, AC_DEFINE replaces "#undef" in a header template, so my patch conditionally rewrites #ifndef _DARWIN_USE_64_BIT_INODE # undef _DARWIN_USE_64_BIT_INODE #endif to either #ifndef _DARWIN_USE_64_BIT_INODE /* #undef _DARWIN_USE_64_BIT_INODE */ #endif or #ifndef _DARWIN_USE_64_BIT_INODE # define _DARWIN_USE_64_BIT_INODE 1 #endif depending on the value of $enable_largefile. > Are you stating that you don't need the AH_VERBATIM at all, and can > instead just use an AC_DEFINE to get the semantics you want? Yes, AC_DEFINE is all I need. In fact I don't really understand why AC_SYS_LARGEFILE uses AH_VERBATIM to conditionally define _DARWIN_USE_64_BIT_INODE. Just in case a compiler defines it by default? > And these days, compiling without large file support is rather > anti-climactic; gnulib, for example, has already decided that it is much > easier to always insist on large file support than it is to try to make > it user-configurable. I have no objection to always enable large file support. I just need a consistent ino_t both on configure time and build time. _______________________________________________________ - PHO - http://cielonegro.org/ OpenPGP public key: 1024D/1A86EF72 Fpr: 5F3E 5B5F 535C CE27 8254 4D1A 14E7 9CA7 1A86 EF72
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