Michał Górny schrieb: > Dnia 2014-06-11, o godz. 15:30:26 > Chí-Thanh Christopher Nguyễn <chith...@gentoo.org> napisał(a): > >>> 3. There is no clean way of enforcing SSL provider match between >>> packages. Wasn't this thread initially about curl and rtmpdump >>> requiring matching flags? >> It could be enforced if an eclass does the actual choice of crypto >> provider in a reproducible way. That would be not trivial though. > No, it can't. Let's say package A depends on package B and requires > the same SSL provider. > > A has 'openssl gnutls' > B has 'openssl gnutls polarssl' > > Now let's say the eclass prefers polarssl over the other two. How are > you going to make A dep on B? >
It is not trivial, but I don't think it is impossible. I had thought of the following, but have not carefully checked that it covers all cases. crypto-providers.eclass would have a list CRYPTO_PROVIDERS_SUPPORTED sorted descending by priority, and A and B would pass in a variable CRYPTO_PROVIDERS the acceptable providers. The eclass would provide functions which expand into USE dependencies to ensure that no higher-prioritized crypto provider is selected in B. Example: crypto-providers.eclass: CRYPTO_PROVIDERS_SUPPORTED="polarssl openssl gnutls libgcrypt libnettle ..." crypto-providers_only() returns USE dependency on its arguments, and negative USE dependencies for all providers with higher priority, e.g. crypto-providers_only(gnutls) returns "-crypto_providers_polarssl(-) -crypto_providers_openssl(-) crypto_providers_gnutls(-)" crypto-providers_match(packagename) returns priority nested USE conditionals for all CRYPTO_PROVIDERS that can be fed into DEPEND, e.g. crypto_providers_match(B) would return "crypto-providers_openssl? ( B[$(crypto_providers-only(openssl)] ) !crypto-providers_openssl? ( crypto-providers_gnutls? ( B[$(crypto_providers-only(gnutls)] ) )" A.ebuild CRYPTO_PROVIDERS="openssl gnutls" DEPEND="$(crypto-providers_match(B))" B.ebuild CRYPTO_PROVIDERS="openssl gnutls polarssl" Best regards, Chí-Thanh Christopher Nguyễn
