Re: config.status produces incompatible defines.awk and config.h

[Eric Blake]

On 09/02/2010 05:30 PM, Hoyt, David wrote:
> I'm unsure if this is a binutils-specific issue or not, since I'm told that 
> gcc-related projects use their own configuration environment. But I noticed the 
> following when attempting to compile binutils...
>
> config.h was not being created correctly on my Windows 7 (x86_64) machine using the latest released 
> tools from msys/mingw, causing all sorts of build problems. After investigating the issue, it was 
> narrowed down to a problem with how config.status produces and then uses defines.awk. That awk file 
> uses a regular expression that looks for lines like "#undef VALUE_HERE" to eventually 
> change them to "#define VALUE_HERE 1" if configure deems it so, but it wasn't finding 
> them due to mismatches from Windows-style line endings.

Thanks for the report.  Autoconf already has some attempted support for 
CRLF line endings in config.status, but it has had issues over time. 
Which version of autoconf are you dealing with?  It may be that you are 
facing an issue with gcc using an older version of autoconf, where 
upgrading to a newer version would resolve things.

Also, have you considered using binary-mode mounts under cygwin, rather 
than text-mode mounts under msys?  That right there would eliminate your 
CR issues, although it implies a different set of cross-compilation 
issues to deal with.  That's probably straying outside what this list 
can support, but I know there are better forums out there for people who 
are actively working on development of gcc for various windows targets.

> +++ defines.awk Thu Sep  2 15:56:01 2010
> @@ -51,8 +51,9 @@
>     for (key in D) D_is_set[key] = 1
>     FS = " "
>   }
> -/^[\t ]*#[\t ]*(define|undef)[\t 
> ]+[_abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ][_abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789]*([\t
>  (]|$)/ {
> +/^[\t ]*#[\t ]*(define|undef)[\t 
> ]+[_abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ][_abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789]*([\t
>  (]|\r$)/ {
>     line = $ 0
> +  sub(/\r$/, "", line)

As written, this patch is not portable.  Rather, if the current 
autoconf.git does not already address the issue, then you will need to 
use the same approach as is already in lib/autoconf/status.m4; notice 
how $ac_cr and $ac_cs_awk_cr are used to find a portable spelling of CR 
that will work for whichever awk will be processing the define script.

--
Eric Blake   address@hidden    +1-801-349-2682
Libvirt virtualization library http://libvirt.org