On 16-Mar-2006, David Bateman wrote:
| Please find attached the patch of all of the code I have for 2.9.5. It
| includes a number of changes a fixes for the sparse matrix type, but also an
| attempt at a fix for a valgrind identified problem for strncmp, where I
| introduce a means of detecting the size of the string in the OSSTREAM and
| ensure it is longer than the length argument to strncmp. This didn't appear
| to fix the issue for me and so I suspect the problem is due to my gcc
| 4.0.1libc strncmp function and similar issues are identified in
| readline.
| However, the patch for this seems useful in any case and so I supply it. Now
| that the test code is stabilizing its probably worthwhile taking the many
| hours time necessary to run
|
| % cd test
| % LD_LIBRARY_PATH="`pwd`/../src:`pwd`/../liboctave:`pwd`/../libcruft"
| valgrind --tool=memcheck ../src/octave -f -q -H -p
| .//:../src//:.:./../scripts// ./fntests.m .
|
| to get a complete list of all of the problems that valgrind can identify
| with the current test code. However, give the above problem I have, I'm not
| sure I'm the best to do this. I did this for the sparse test code, and only
| identified the strncmp problem above in ls-oct-ascii.{cc,h}.
|
| Other major things in this patch include
|
| * Make the calculation of the condition number optional and disable it for
| the diagonal, triangular and banded solvers as the calculation of the
| condition number takes longer that the solution of the linear equation in
| this case (often by orders of magnitude). The underlying code shouldn't
| allow singular matrices to be treated in this case, so I see this as a major
| improvement
| * Special case sparse permutations for Sparse<T>::index function, and gain
| several orders of
| magnitude of speed in this case.
| * Dulmange-Mendelsohn sparse QR solver. This should give significantly
| better solutions for over-determined problems.
| * Many bug fixes for rectangular solvers.
|
| Please find attached the patch and a complete changelog file..
I can't comment on the Sparse stuff since I don't know much about it.
You are the expert there, so go ahead and check in those changes.
I don't really want the strncmp change because it seems to be a bug in
strncmp since that function is supposed to compare at most N
characters. We should not have to include checks for that ourselves.
In any case, how about this change? Does it also avoid the problem?
I also see one other call to strncmp in util.cc that could be
converted to use the std::string compare method.