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Hello,this patch solves bug #16009 by implementing an additional path in strxfrm that does not depend on caching the weight and rule indices.
In detail the following changed:* The old main loop was factored out of strxfrm_l into the function do_xfrm_cached to be able to alternativly use the non-caching version do_xfrm.
* strxfrm_l allocates a a fixed size array on the stack. If this is not sufficiant to store the weight and rule indices, the non-caching path is taken. As the cache size is not dependent on the input there can be no problems with integer overflows or stack allocations greater than __MAX_ALLOCA_CUTOFF. Note that malloc-ing is not possible because the definition of strxfrm does not allow an oom errorhandling.
* The uncached path determines the weight and rule index for every char and for every pass again. Handling of backward sequences needs a special threatment, I found no way to implement it without allocation. This is now done by pushing the backward sequence on the stack within a single linked list that can later easily be traversed backwards (but not free'd) and avoids the problem of stack allocations beyond __MAX_ALLOCA_CUTOFF. Here again, malloc is not possible.
* Passing all the locale data array by array resulted in very long parameter lists, so I introduced a structure that holds them.
* Checking for zero src string has been moved a bit upwards, it is before the locale data initialization now.
* To verify that the non-caching path works correct I added a test run to localedata/sort-test.sh & localedata/xfrm-test.c where all strings are patched up with spaces so that they are too large for the caching path.
make tests && make xcheck report no additional errors. Unfortunately the diff of strxfrm_l.c is a bit messy, it looks factoring out the main loop was too much for git. :|
Leonhard 2014-11-29 Leonhard Holz <leonhard.holz@web.de> [BZ #16009] * string/strxfrm_l.c (STRXFRM): Allocate fixed size cache for weights and rules. Use do_xfrm_cached if data fits in cache, do_xfrm otherwise. Moved former main loop to... * (do_xfrm_cached): New function. * (do_xfrm): Non-caching version of do_xfrm_cached. Uses find_idx, find_position and stack_push. * (find_idx): New function. * (find_position): Likewise. * (stack_push): New macro. * localedata/sort-test.sh: Added test run for do_xfrm. * localedata/xfrm-test.c (main): Added command line option -nocache to run the test with strings that are too large for the STRXFRM cache.
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