Re: [PATCH 00/15] Add libunistring-optional module

[Bruno Haible]

Hi Paolo,

> 1) Is it so bad to drop the complicated code for 0.9-0.9.3 version
> detection, and just assume 0.9 if the hexversion is 9?

It may be possible three years from now. But currently, 0.9.3 is the newest
version available, and you'll notice that many modules carry 0.9.1 or 0.9.3
as minimum acceptable version. People would not understand why, despite having
installed the newest available release, the machinery would still compile
the code included in the package. In other words, there would be little
incentive of using --with-libunistring-prefix.

> 2) What's the purpose of gl_LIBUNISTRING_VERSION_CMP_ORIG?

It serves as a backup, for the case that some day we need to pass computed
versions instead of literal versions.

> Why not add an 
> 
> AS_LITERAL_IF([$1], , [m4_fatal([Argument of ]dnl
> [[gl_LIBUNISTRING_VERSION_CMP] must be a literal])])
> 
> and drop the macro for the non-literal case?

Because that's what I call a "premature optimization" (in the sense of Knuth).
And AS_LITERAL_IF was not documented in Autoconf < 2.64.

Bruno