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I'm working on some EAPI extensions with the goal of making Portage |
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more powerful for cross-compilation. See |
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https://bugs.gentoo.org/show_bug.cgi?id=317337 |
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Currently, it's come down to the following: |
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|
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- A new dependency type HDEPEND for packages which must be installed |
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in / at build time. With HDEPEND present in the new EAPI (probably |
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4-hdepend), DEPEND will always mean ROOT (target) dependencies, and |
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will no longer be affected by --root-deps option. |
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|
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- Another dependency type CROSS_HDEPEND, like HDEPEND, but in effect |
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only when cross compiling. This in particular is required for packages |
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which need themselves on the host when cross compiling, and adding |
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this to HDEPEND would make a package not buildable on native due to a |
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circular dependency. |
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|
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- A --crosscompile option to tell emerge when we are cross compiling, |
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and this triggers CROSS_HDEPEND (except for installs to /). Basically |
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we don't want emerge doing any black magic guessing like comparing |
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CHOST. |
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|
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But the one thing missing currently is a way to check from within an |
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ebuild function whether we are cross compiling, in a way that would |
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correspond directly to --crosscompile (again, except for /). There is |
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currently "tc-is-cross-compiler" from toolchain-funcs.eclass, but this |
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may not work right when not at build time (pkg_{pre,post}{inst,rm}), |
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and it also may not correspond to presence of --crosscompile. |
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|
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The question now is, how should this method for checking |
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--crosscompile be implemented? In particular, we have two options: |
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|
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- Environment variable. If so, how to call it? Possible names are |
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CROSSCOMPILE, GENTOO_CROSSCOMPILE, PORTAGE_CROSSCOMPILE, |
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ECROSSCOMPILE... For more generic names (CROSSCOMPILE) it needs to be |
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taken into account that they may inadvertently affect packages. |
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However environment vars have the benefit that it's easy to pass them |
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through programs and scripts. |
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|
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- Internal function, similar to "use". Probably "is_crosscompile". |
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This may look nicer and reduces the risk of collisions. |
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|
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This RFC is only about checking for presence of --crosscompile. Please |
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do not discuss HDEPEND in general here, or anything that would require |
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major effort to get done. |
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