This is a followup from some chat in #yocto and elsewhere. To make a long story short, some of the commercial vendors (like Wind River) tend to ship prebuilt binaries for glibc, and want to require these binaries to be used as-is (unless the user has done something special and is building libc). It would be convenient for people providing replacement toolchain layers to be able to catch attempts to build something that will fail because there are no corresponding libc binaries.
With prebuilt libraries, the library is not always built with the exact same flags that everything else is, but it needs to be ABI-compatible with them. With that in mind, I coin the name "TUNEABI" to refer to the descriptor for a prebuilt library. This is basically like a tuning, but it's special in that multiple tunings can refer back to it as a thing they are based on or will work with. So I define a couple of values: 1. TUNEABI_WHITELIST. This is a space-separated list of tuneabi values which are supported. If this list does not exist, nothing happens; the check is a no-op. 2. TUNEABI_OVERRIDE. If this value exists, it suppresses the check even if TUNEABI_WHITELIST is set. This is sort of a placeholder for whatever people want to do about specifying a rebuild instead of using prebuilts. 3. TUNEABI_tune-foo. This specifies the (space-separated list of) tuneabis that can support the tuning foo. If absent, the tuning name is used. Intended use: Imagine that you are distributing a toolchain layer which has only one ARM library, which is armv7 thumb2, you would specify TUNEABI_WHITELIST = armv7at. Then a build for armv7at would work, but a build for armv6t would fail. If you are using the interwork feature, you might also specify TUNEABI_tune-armv7a = armv7at; then armv7a builds would be allowed also. The intent of this is that if you're providing a toolchain, and you want to support a limited set of prebuilt libraries, this check should be able to let you specify what you need without necessarily having to replace all the existing tuning and configurations. All you have to do is provide TUNEABI_tune-foo settings for any tunings you know to work with your libraries, and a TUNEABI_WHITELIST value, and the sanity check should catch everything likely. Thoughts, feedback? -s -- Listen, get this. Nobody with a good compiler needs to be justified. _______________________________________________ Openembedded-core mailing list Openembedded-core@lists.openembedded.org http://lists.linuxtogo.org/cgi-bin/mailman/listinfo/openembedded-core
