Timeline for Was there a bug in Wirth's original Pascal compiler?
Current License: CC BY-SA 4.0
11 events
| when toggle format | what | by | license | comment | |
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| Jun 7, 2021 at 15:02 | vote | accept | Leo B. | ||
| Jun 5, 2021 at 8:30 | comment | added | Leo B. | @texdr.aft Thank you! Apparently the hand-written parser of Turbo Pascal was quite deficient. Out of the two compilers I have, one says "semicolon required", pointing to ":="; the other says "no END", mentioning "foo" as the last identifier parsed. | |
| Jun 5, 2021 at 8:02 | comment | added | texdr.aft | I found an explanation for the strange Turbo Pascal error: news.ycombinator.com/item?id=6573092 | |
| Jun 3, 2021 at 8:02 | history | became hot network question | |||
| Jun 3, 2021 at 2:00 | answer | added | texdr.aft | timeline score: 12 | |
| Jun 3, 2021 at 0:58 | comment | added | Leo B. | (1) Yes, homepages.cwi.nl/~steven/pascal/p4c.tar.gz (2) Right; Although judging by the timeline (the first BESM-6 compiler was released in 1976), they could be based on the P-series rather than the original. | |
| Jun 3, 2021 at 0:52 | comment | added | texdr.aft | (1) C source of P4? (2) By independent do you mean not derived from the P series? | |
| Jun 3, 2021 at 0:49 | comment | added | Leo B. | @texdr.aft I was just a few minutes behind you; having run that experiment myself after spending some time fixing the C source of P4. The high error code was a hint. But it would be instructive to see an independent compiler with the bug in action. | |
| Jun 3, 2021 at 0:35 | comment | added | texdr.aft | The error code displayed by P4 is 177 ("You may only assign to the identifier of a function in the body of that function", see homepages.cwi.nl/~steven/pascal/book/…), which was not included in the list of error codes at the end of the Pascal user manual, so I would propose that the answer to your question is yes. | |
| Jun 3, 2021 at 0:29 | comment | added | texdr.aft |
Compare the source code of the func branch of the selector routine in the P2 compiler (search for "IMPL. RELAT. ADDR. OF FCT. RESULT" to find the relevant line) and in the P4 compiler. In the latter there is an error check complaining if a function name is assigned to outside its body. (In adding the check, an odd begin-end pair was left, as noted in Daniels and Pemberton's book about P4).
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| Jun 2, 2021 at 23:58 | history | asked | Leo B. | CC BY-SA 4.0 |