Re: Compile Time vs. Run Time, Mixed Language Compiling, Fat Code

chased@rbbb.Eng.Sun.COM (David Chase)
Wed, 13 Jan 1993 17:49:06 GMT

          From comp.compilers

Related articles
[3 earlier articles]
Re: Compile Time vs. Run Time, Mixed Language Compiling, Fat Code eifrig@beanworld.cs.jhu.edu (1993-01-12)
Re: Compile Time vs. Run Time, Mixed Language Compiling, Fat Code tmb@arolla.idiap.ch (1993-01-12)
Re: Compile Time vs. Run Time, Mixed Language Compiling, Fat Code jlg@cochiti.lanl.gov (1993-01-12)
Re: Compile Time vs. Run Time, Mixed Language Compiling, Fat Code drw@euclid.mit.edu (1993-01-12)
Re: Compile Time vs. Run Time, Mixed Language Compiling, Fat Code wilson@ann-arbor.applicon.slb.com (1993-01-13)
Re: Compile Time vs. Run Time, Mixed Language Compiling, Fat Code nickh@CS.CMU.EDU (1993-01-13)
Re: Compile Time vs. Run Time, Mixed Language Compiling, Fat Code chased@rbbb.Eng.Sun.COM (1993-01-13)
Re: Compile Time vs. Run Time, Mixed Language Compiling, Fat Code bart@cs.uoregon.edu (1993-01-14)
Re: Compile Time vs. Run Time, Mixed Language Compiling, Fat Code rv@erix.ericsson.se (1993-01-14)
Re: Compile Time vs. Run Time, Mixed Language Compiling, Fat Code smk@dcs.edinburgh.ac.uk (1993-01-14)
Re: Compile Time vs. Run Time, Mixed Language Compiling, Fat Code tmb@arolla.idiap.ch (1993-01-15)
Re: Compile Time vs. Run Time, Mixed Language Compiling, Fat Code ken@eies2.njit.edu (1993-01-16)
| List of all articles for this month |

Newsgroups: comp.compilers
From: chased@rbbb.Eng.Sun.COM (David Chase)
Organization: Sun
Date: Wed, 13 Jan 1993 17:49:06 GMT
Keywords: types, debug
References: 93-01-041 93-01-078

jlg@cochiti.lanl.gov (J. Giles) writes:
>... The article I was responding to made claim that
>programs which pass the typechecker of a strictly typed language never
>have bugs (the exact statement was " An SML program which successfully
>typechecks will not bomb at runtime").


>This latter is clearly wrong. Not only *CAN* programs which are free of
>type errors still contain bugs, those remaining bugs are the hardest to
>find and correct: they account for the vast majority of debugging time.


I think you misinterpreted the meaning of the word "bomb". Clearly, what
is meant in this context is that a successfully type-checked SML program
will not destroy its abstract machine. Pointers will not accidentally be
overwritten with floating point numbers, the stack will not accidentally
be corrupted, and run-time data structures will remain sane.


What this means is that the you can debug your program at the "language
level" and not at the "compiled" (machine) level. In a large system,
pointer smashes are among the hardest bugs to fix, and avoiding them is a
good thing, even if other very hard bugs remain.


David Chase
Sun
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