program nestbug(output); (* nestbug: bugs in gpcc with the use of --nested-comments Dr. Thomas D. Schneider National Cancer Institute Laboratory of Experimental and Computational Biology Frederick, Maryland 21702-1201 toms@ncifcrf.gov permanent email: toms@alum.mit.edu http://www.lecb.ncifcrf.gov/~toms/ *) label 1; (* end of program *) const (* begin module version *) version = 1.00; (* of nestbug.p 2000 July 11 1.00; 2000 July 11 origin *) updateversion = 1.00; (* defines lowest acceptable current parameter file *) (* end module version *) (* begin module describe.nestbug *) (* name nestbug: bugs in gpcc with the use of --nested-comments synopsis nestbug(output: out) files output: messages to the user description This code demonstrates a bug in gpc: GNU Pascal version 20000707, based on gcc-2.95.2 19991024 (release). which when called on this program as: gpc --standard-pascal --nested-comments --transparent-file-names $nestbug.p -o $nestbug will object as follows: nestbug.p:54: parse error before `Documentation' because, although the --nested-comments is on, it still can't handle this unbalanced right curlie bracket: } examples documentation see also {GPC will also object to the } shell.p {program at} http://www.lecb.ncifcrf.gov/~toms/delila/shell.html author Thomas Dana Schneider bugs 1. See above. 2. ADDITIONAL BUG: Note also that GPC capitalizes the word "Documentation", which is confusing and it should not do. Someone doing a case sensitive search would not find the problem! This occurs in other places in the code. GPC should NEVER change cases!!!! (Oh, I see. In German one capitalizes nouns. Perhaps this is why you thought to do it. The rest of the world does not and it will cause confusion and trouble. How about creating a --German command line option? :-) 3. The use of the unbalanced bracket was legitimate in the shell program as part of a quoted string inside the documentation comments. { I infer that when comments are parsed gpc does not remember the kind of starting comment. It should recall that the comment of this documentation began with a left-parenthesis-astrisk, and so should ignore everything until it encounters an astrisk-right parenthesis. Apparently it doesn't and is sensitive to the curlie brackets. (The reverse should hold inside a curlie bracket comment of course.) } 4. If the curlies around the above paragraph are deleted, the message is: nestbug.p:92: unterminated string or character constant nestbug.p:83: possible real start of unterminated constant The program is sensitive to single quote marks! I had the word "doesn't" in the bugs section, and it blocked the case mentioned above! The curlie brackets above protect the single quote! The whole comment skipping code needs a careful overhaul! It should not be looking at quotes at all during comment skipping! technical notes The program does a successful goto to the end of the code from the halt routine, so that bug is FIXED. :-) :-) Thank you! *) (* end module describe.nestbug *) (* begin module halt *) procedure halt; (* stop the program. the procedure performs a goto to the end of the program. you must have a label: label 1; declared, and also the end of the program must have this label: 1: end. examples are in the module libraries. this is the only goto in the delila system. *) begin writeln(output,' program halt.'); goto 1 end; (* end module halt version = 'delmod 6.16 84 mar 12 tds/gds'; *) (* begin module nestbug.themain *) procedure themain; (* the main procedure of the program *) var parameterversion: real; (* parameter version number *) begin writeln(output,'nestbug ',version:4:2); halt; end; (* end module nestbug.themain *) begin themain; 1: end.