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Diffstat (limited to 'NEWS')
| -rw-r--r-- | NEWS | 34 |
1 files changed, 33 insertions, 1 deletions
@@ -1,9 +1,41 @@ -Version 0.15.0 +Version 0.16.0 * The in.substitution variable has been renamed to in.mode. The original name is still recognized for backwards compatibility. + * Support for post hoc prerequisites. + + Unlike normal and ad hoc prerequisites, a post hoc prerequisite is built + after the target, not before. It may also form a dependency cycle together + with normal/ad hoc prerequisites. In other words, all this form of + dependency guarantees is that a post hoc prerequisite will be built if its + dependent target is built. + + A canonical example where this can be useful is a library with a plugin: + the plugin depends on the library while the library would like to make + sure the plugin is built whenever the library is built so that programs + that link the library can be executed without having to specify explicit + dependency on the plugin (at least for the dynamic linking case): + + lib{hello}: ... + lib{hello-plugin}: ... lib{hello} + libs{hello}: libs{hello-plugin}: include = posthoc + + Note that there is no guarantee that post hoc prerequisites will be built + before the dependents of the target "see" it as built. Rather, it is + guaranteed that post hoc prerequisites will be built before the end of the + overall build (more precisely, before the current operation completes). + As a result, post hoc prerequisites should not be relied upon if the + result (for example, a source code generator) is expected to be used + during build (more precisely, within the same operation). + + Note also that the post hoc semantics is not the same as order-only in + GNU make. In fact, it is an even more "relaxed" form of dependency. + Specifically, while order-only prerequisite is guaranteed to be built + before the target, post hoc prerequisite is only guaranteed to be built + before the end of the overall build. + Version 0.15.0 * Generated C/C++ headers and ad hoc sources are now updated during match. |