[Rochus]

Deploying an application was always an adventure. You could never be completely sure that it didn't contain things it shouldn't.

[igouy]

( cont. from https://news.ycombinator.com/item?id=31999774 )

> … no algorithm that can identify all dead code reliably…

Why were you so concerned with the removal of all dead code?

Compared to "… nobody had the source code…" it seems like a minor issue.

[igouy]

( cont. )

imo the more usual concern would be mistakenly removing code that was not dead.

Without a design document, we might think there would be no senders of #factorial without understanding that the intention was to invoke that method on the command line.

For example,

    $ cat fact.st
    Stdio stdout 
        nextPutAll: 100 factorial printString; 
        nextPut: Character lf.!
    SmalltalkImage current snapshot: false andQuit: true!

    $ bin/pharo --headless Pharo10-SNAPSHOT-64bit-502addc.image fact.st
    93326215443944152681699238856266700490715968264381621468592963895217599993229915608941463976156518286253697920827223758251185210916864000000000000000000000000

So instrumenting methods and logging — https://stackoverflow.com/a/162719

[igouy]

For some meaning of "contain things it shouldn't":

Given that the base image we started working with didn't "contain things it shouldn't" why could we not be completely sure that base image + source code fileIn didn't "contain things it shouldn't" ?

[Rochus]

First, as most other companies using ST we were not working on the original image, but on a company-specific one that had been in use for a long time and contained a lot of company-specific stuff. On the other hand, there were also things in the original images of the commercial STs that one would or should not ship with the product.

[igouy]

Firstly:

company-specific base image = base image + company-specific source code fileIn

Why could we not be completely sure that company-specific base image + source code fileIn didn't "contain things it shouldn't" ?

Secondly:

> … also things in the original images of the commercial STs that one would or should not ship with the product.

That doesn't seem to be an example of "You could never be completely sure that it didn't contain things it shouldn't."

That seems to be an example of you being completely sure.

[Rochus]

Not sure what you're up to; there were things in the image nobody had the source code (or the current version) anymore, but even with the source code it was a nightmare; it would undoubtedly have been less bad had I then had tools like I recently built for ST80 and the knowledge gained with them.

[igouy]

> … nobody had the source code … anymore…

!

Would we blame Ada tools because we did not archive the source code we wrote?

> … even with the source code it was a nightmare…

What I was "up to" was trying to get past sweeping condemnation to understandable criticism.

[Rochus]

That was my personal impression as a trained engineer based on relevant experience, not a condemnation; I on the other hand find it annoying when some people glorify Smalltalk in retroperspective and attribute to it any great qualities without evidence and against better knowledge; nevertheless, the technology is impressive in a historical context and worth studying (but I still wouldn't use it for industrial projects anymore and would also not like to tempt other people).

[pjmlp]

Which is why image trimming tools did exist.

[Rochus]

I had Envy in later projects, which was very useful, but you simply had to trust it, which is not the same as to be completely sure.

[igouy]

Rather than simply trust, wouldn't we test?

(At some point, we might question whether we're putting similar effort into testing other software tools.)

[Rochus]

We tested until our ears fell off; in particular, we had also to test all the stuff that the compiler (or linker) would otherwise have told us in a statically typed language; there was no other way; might explain why I directly switched to Ada for some time after ST; but how do you test for dead code (i.e. things in the image not used but still there for some reason)? It is not for nothing that people speak of a "Big ball of Mud" in the context of image based languages.