Software Quality in Science
in [ADA]
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From: Robert A Duff on 12 Feb 2010 10:02 Stephen Leake <stephen_leake(a)stephe-leake.org> writes: > It's -gnatyO, and it's off by default. And turning it on exposes > missing 'overriding' keywords in the standard library. So it's not > quite ready for real time yet. (yes, I've filed bug reports) Thanks for the bug reports. We should really fix those! In fact, we should probably be compiling the runtimes with -gnatyO. - Bob
From: Alex R. Mosteo on 15 Feb 2010 05:49 Robert A Duff wrote: > "Hibou57 (Yannick Duchêne)" <yannick_duchene(a)yahoo.fr> writes: > >> But Ada provides a nice way to avoid it : systematically make use of >> "overriding" / "not overriding". The dark side is that this is >> optional and not required by the language rules. > > There's an option in GNAT to warn about this. > I don't remember if it's turned on by default. > (I think not.) I requested this feature at AdaEurope'08 IIRC. Nice to know it's there :)
From: Colin Paul Gloster on 15 Feb 2010 06:08 On Tue, 9 Feb 2010, Jerry sent: |----------------------------------------------------------------------| |"Here is the link in the Guardian article to the original work: | | | |http://www.leshatton.org/Documents/Texp_ICSE297.pdf | | | |It appears that this work was done in the 1990s. The paper is actually| |fairly entertaining to read, if for nothing else how scary it is. Here| |is a choice comment, about a commercial program for use in the nuclear| |engineering industry: | | | |"This package climbed to an awe-inspiring 140 weighted static faults | |per 1000 lines of code, and in spite of the aspirations of its | |designers, amounted to no more than a very expensive random number | |generator."" | |----------------------------------------------------------------------| I am a nuclear scientist, and I confirm that software used for supposedly simulating nuclear reactions is dangerous. For example, HTTP://HyperNews.SLAC.Stanford.edu/HyperNews/geant4/get/phys-list/545.html Nuclear electricity should be illegal. |----------------------------------------------------------------------| |"And this comment which addresses the use of Ada: | | | |"In C, note that function prototypes were well used only around 60% of| |the time and as a result, interface faults accounted for about 24% of | |the total. In other words, if function prototypes were mandated in all| |C functions, 24% of all serious faults would disappear. The | |computational scientist should not use this as an argument in favour | |of C++ or Ada in which they are mandated. A large number of new | |failure modes result from this action, which lack of space prohibits | |further discussion here. The net result of changing languages appears | |to be that the overall defect density appears to be about the same, | |(Hatton 1997). In other words, when a language corrects one | |deficiency, it appears to add one of its own."" | |----------------------------------------------------------------------| Why did that entertain you?
From: Colin Paul Gloster on 15 Feb 2010 06:20 On Wed, 10 Feb 2010, Florian Weimer wrote: |-------------------------------------------------------------------| |"[..] | | | |even lines of code) vary as much among programmers [..]" | |-------------------------------------------------------------------| Of course. In C++ I produce if(condition) { statement; } but I have been profiling C++ code by someone else which contained instead if (condition) statement; which with a profiler which profiles per line instead of per statement does not enlighten me as to whether or not the condition has ever been true. |-------------------------------------------------------------------| |"[..] This is a bit sad because it means that | |language design does not really matter as far as actual results are| |concerned. | | | |[..]" | |-------------------------------------------------------------------| You were mistaken.
From: Colin Paul Gloster on 15 Feb 2010 06:32
On Wed, 10 Feb 2010, Stephen Leake wrote: |---------------------------------------------------------------------| |"[..] | | | |The programmers still have to specify the right switches, and pay | |attention to the results, and know how to fix them, which is a | |political/management/skill issue, not a language design issue. | | | |I know from personal experience that there is a satellite about to be| |launched who's control code has many remaining C warnings. Sigh." | |---------------------------------------------------------------------| Yes, people are idiots. Colin Paul Gloster, who used to work for the European Space Agency and who was forced to use C in a squanderous waste of taxpayers' monies |