Am Mon, 2002-02-04 um 22.58 schrieb Tom Tromey: > >>>>> "Ralf" == Ralf Corsepius <[EMAIL PROTECTED]> writes: > > Ralf> But I think, the actual cause for this issue is something different: > > Ralf> 3) AM_INIT_AUTOMAKE([no-define]) allows config-headers to be > Ralf> exported, ie. to export and thereby globally store configuration > Ralf> information. > > Ralf> IMO, users, using AM_INIT_AUTOMAKE([no-define]), normally are > Ralf> not interested in 1), however actually want to have a means to > Ralf> export very few essential package configuration details to > Ralf> user-space. > > While that's true, it is also the case that if you are doing this you > are expected to be responsible for the namespace. My reasoning here > is that generally it is library authors who export config headers, and > library authors are supposed to understand and respect namespace > conventions. Right.
My point is, users are miss-using config-headers for this purpose because autoconf/automake does't provide appropriate/efficient means to assist users in implementing such external config-headers and because using config-headers seems to be compelling to them. > In libgcj we have an internal config header and a much smaller exteral > config header. In the latter we were careful about how we named all > the symbols we use. > Defining HAVE_SOMETHING in an exported header is always wrong. What > if someone else wants to use your package and they have a conflicting > symbol? You've just violated their namespace expectations. Fully agreed, but in most (probably all) cases, the values users actually want to export are either user-supplied (WITH_SOMETHING, ENABLE_SOMETHING) or the result of processing of user-processing options They actually want to store a package's configuration, not to detected features. It's the autotools which unwantedly pull-in HAVE_* and other AC_DEFINES as side-effect. > Of course, some people don't do this. For instance in the past I > think libjpeg used to export a bogus header. Yep. > Unfortunately it isn't always possible to enforce good manners. Then let me emphasize it: This is what currently is happening - autoconf's AC_DEFINE-ing PACKAGE_* enforce users not to export config-headers. Ralf
