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developingpld:advanceddeveloping:fixingasneeded
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developingpld:advanceddeveloping:fixingasneeded [2006-08-08 15:42] SamChi - typo |
developingpld:advanceddeveloping:fixingasneeded [2007-05-27 20:51] (current) arekm |
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| - | ==== Quick Workaround ==== | + | ===== Quick and ugly workaround (DON'T USE IT!) ===== |
| - | Put in spec file this line: | + | Put this line in ''spec'' file: |
| + | |||
| <file>%define filterout_ld -Wl,--as-needed | <file>%define filterout_ld -Wl,--as-needed | ||
| </file> | </file> | ||
| - | But **don't use it** unless you really need. | + | But **don't use it** unless you really need to quickly build a package. Never ever try to commit such a change. It might be tempting to do so but if you think about it ''--as-needed'' did it's job well and disabled unneeded libraries. If building fails, it's the package that needs to get fixed, not the linker flags. |
| - | + | ||
| - | Why ? Because it's very stupid. If something fails to build normally it's a sign ''--as-needed'' did well it's job and disabled unneeded libraries. | + | |
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| - | == About positions == | + | ==== Why it fails for some packages ==== |
| + | In other words, if you list 10 libraries and only 3 of them contain referenced symbols, others are silently discarded. This is a good thing but unfortunately some projects fail to list all their dependencies properly. | ||
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| + | This normally works because if project requires libraries //A// and //B// and //A// itself lists //B// as a dependency, both //A// and //B// get pulled in even if the project itself only lists //A//. | ||
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| + | Now assume that //A// is a superfluous (unneeded) dependency which gets dropped (or //A// requiring //B// is superfluous and //B// gets dropped from //A//). The symbols are no longer available. | ||
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| + | ==== About positions ==== | ||
| Linker options are positional, and position is very important. It looks for missing symbols only in libraries coming after object file. | Linker options are positional, and position is very important. It looks for missing symbols only in libraries coming after object file. | ||
developingpld/advanceddeveloping/fixingasneeded.1155044545.txt.gz · Last modified: 2006-08-08 15:42 by SamChi
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