[asterisk-dev] [Code Review] Out-of-tree modules can fail because of compiler flag differences.

[Kevin Fleming]

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Another thought came to mind this evening... it may be a bit hard to explain, but I'll try.

It will be important that after this change is committed, if any functions (not macros) that will be part of the ABI have names that were part of the ABI before, but have different prototypes, they *must* have different names. It's imperative that anyone who upgrades to a new version of Asterisk with these changes who has binary modules of any kind get symbol resolution errors at module load time, instead of random crashes and other bizarre behavior.

- Kevin


On 2010-03-02 17:40:06, Jason Parker wrote:
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> This is an automatically generated e-mail. To reply, visit:
> https://reviewboard.asterisk.org/r/508/
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> (Updated 2010-03-02 17:40:06)
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> Review request for Asterisk Developers.
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> Summary
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> When compiling modules out-of-tree, there is a large potential for ABI breakage, due to changing compiler flags.  If Asterisk is compiled with DEBUG_THREADS, and an out-of-tree module is not, it should not give undefined symbol errors during load (in fact, there's no reason it shouldn't work).  The biggest problem areas seemed to be DEBUG_THREADS and DEBUG_CHANNEL_LOCKS.
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> Is this the right way to go about this?
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> Note: Many of the functions in lock.h had to be moved into a .c file (main/lock.c).  They were defined as static inline, which defeats much of the purpose.  A module *would* have the information about where a lock was obtained, but since it was including lock.h without DEBUG_THREADS enabled, it wouldn't bother logging it - even though Asterisk would really like it to.
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> Diffs
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>   /branches/1.4/include/asterisk/astobj2.h 249888 
>   /branches/1.4/include/asterisk/lock.h 249888 
>   /branches/1.4/main/Makefile 249888 
>   /branches/1.4/main/astobj2.c 249888 
>   /branches/1.4/main/channel.c 249888 
>   /branches/1.4/main/lock.c PRE-CREATION 
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> Diff: https://reviewboard.asterisk.org/r/508/diff
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> Testing
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> Compile tests with/without DEBUG_THREADS and DEBUG_CHANNEL_LOCKS work great.  I've not tried building an external module with different flags yet.  I suspect that one would compile fine, but may not act properly, partially because of the note above.
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> Thanks,
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> Jason
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>