If you include the warnings, are there any places where messages are not thrown? I can't quite tell.
Gareth aka. Kit On 16/04/2022 23:39, Wayne Sherman wrote:
Gareth aka. Kit wrote:What happens if you run the program with these false negatives? If you get a buffer overrun, then it is pretty serious.When running in debug mode, I get no range check or overflow errors. A 9-byte sized value when assigned to an 8-byte sized variable gets truncated to 8-bytes. I missed these at first, but when I compile I am getting these warnings: const ShortStringConst8c: TShortString8 = '123456789'; //did not get expected compile error (bug?) (unit1.pas(53,50) Warning: String "123456789" is longer than "8") ShortStringConst8d: TShortString8 = StringConst9; //did not get expected compile error (bug?) (unit1.pas(54,51) Warning: String "123456789" is longer than "8") begin ... ShortStringVar8 := '123456789'; //did not get expected compile error (bug?) (unit1.pas(92,19) Warning: String literal has more characters than short string length) But no compile warnings or errors on these: begin ... CharArrayVar8 := '123456789'; //did not get expected compile errors or warnings CharArrayVar8 := StringConst9; //did not get expected compile errors or warnings ShortStringVar8 := CharArrayVar9; //did not get expected compile errors or warnings ShortStringVar8 := TCharArray9(['1','2','3','4','5','6','7','8','9']); //did not get expected compile errors or warnings ShortStringVar8 := CharArrayConst9; //did not get expected compile errors or warnings So it looks like the compiler does not treat string compatible types as strictly as other types and when assigning it copies as many characters as will fit. But it is not consistent in generating warnings. On Sat, Apr 16, 2022 at 2:24 PM J. Gareth Moreton via fpc-devel <fpc-devel@lists.freepascal.org> wrote:It does look like a bug on the surface. What happens if you run the program with these false negatives? If you get a buffer overrun, then it is pretty serious. Gareth aka. Kit On 16/04/2022 21:35, Wayne Sherman via fpc-devel wrote:Tested with fpc 3.3.1 trunk (as of 2022-Mar-12) and 3.2.2 stable. Ubuntu 20.04 64-bit Good compile time error checking is one of the wonderful things about Pascal. But some char array and shortstring assignments which are not size compatible do not produce a compile error as expected. Please see below. {$mode objfpc}{$H+} type TCharArray8 = packed array[0..7] of Char; TCharArray9 = packed array[0..8] of Char; TShortString8 = string[8]; const StringConst8 = '12345678'; StringConst9 = '123456789'; CharArrayConst8a: TCharArray8 = '12345678'; CharArrayConst8b: TCharArray8 = StringConst8; CharArrayConst8c: TCharArray8 = ('1','2','3','4','5','6','7','8'); //CharArrayConst8d: TCharArray8 = '123456789'; //compile error as expected //CharArrayConst8e: TCharArray8 = StringConst9; //compile error as expected //CharArrayConst8f: TCharArray8 = ('1','2','3','4','5','6','7','8','9'); //compile error as expected ShortStringConst8a: TShortString8 = '12345678'; ShortStringConst8b: TShortString8 = StringConst8; ShortStringConst8c: TShortString8 = '123456789'; //did not get expected compile error (bug?) ShortStringConst8d: TShortString8 = StringConst9; //did not get expected compile error (bug?) var CharArrayVar8: TCharArray8; CharArrayVar9: TCharArray9; ShortStringVar8: TShortString8; begin CharArrayVar8 := '12345678'; CharArrayVar8 := StringConst8; CharArrayVar8 := ['1','2','3','4','5','6','7','8']; //requires fpc 3.3.1 CharArrayVar8 := CharArrayConst8c; //CharArrayVar8 := ['1','2','3','4','5','6','7','8','9']; //compile error as expected CharArrayVar8 := '123456789'; //did not get expected compile error (bug?) CharArrayVar8 := StringConst9; //did not get expected compile error (bug?) CharArrayVar8 := ShortStringVar8; ShortStringVar8 := CharArrayVar8; ShortStringVar8 := '12345678'; ShortStringVar8 := CharArrayConst8a; ShortStringVar8 := TCharArray8(['1','2','3','4','5','6','7','8']); //requires fpc 3.3.1 ShortStringVar8 := '123456789'; //did not get expected compile error (bug?) ShortStringVar8 := CharArrayVar9; //did not get expected compile error (bug?) ShortStringVar8 := TCharArray9(['1','2','3','4','5','6','7','8','9']); //did not get expected compile error (bug?) (requires fpc 3.3.1) end; Should I open a couple of bug reports? _______________________________________________ fpc-devel maillist - fpc-devel@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-devel-- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus _______________________________________________ fpc-devel maillist - fpc-devel@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-devel
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