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On 12/14/10 01:33, Perry Smith wrote: |
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>> Drawback 1: |
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>> It is impossible to specify undefined symbols in an import file for the |
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>> shared object to allow for subsequent link steps keeping those symbols in the |
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>> created shared object or executables, to be resolved by runtime linking when |
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>> the executable is run. |
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>> But as shared libraries with unresolved symbols are broken "by design" anyway, |
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>> and real runtime dependency management isn't going to work with broken shared |
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>> libraries, this becomes a non-problem as more and more packages get this right. |
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> Does #! .. solve this? (from IBM pubs on the ld command) I'm not 100% clear when libraries with unresolved symbols are used. |
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Unfortunately not. A shared object name ".." seems to not have any special meaning |
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to the linker/binder, but the runtime loader only. |
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The problem is that it is a shared object referencing symbols in "..", while the |
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binary (executable or shared object) currently being linked does not need them, |
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so the binder does not see those symbols as undefined. |
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Import files are to inform the binder where to find symbols when they are needed, |
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but they aren't needed by the current binary. |
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It is even more complex: When one shared object references "..", the binder would |
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have to add a reference to a second shared object, when the symbols used from ".." |
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aren't available in some static object. |
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So there is one indirection too much for import files here. |
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> #! .. (Two dots) Use this name to list symbols that will be resolved by the run-time linker. |
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> Use this file name to create shared objects that will be used by programs making use of the run-time linker. |
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> If you use a module that imports symbols from .. in a program that was not linked with the rtllib option, |
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> symbols will be unresolved, and references to such symbols will result in undefined behavior. |
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I've stared at and tried this for weeks without success in my case... |
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/haubi/ |
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-- |
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Michael Haubenwallner |
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Gentoo on a different level |
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