[Bug modula2/109952] New: Inconsistent HIGH values with 'ARRAY OF CHAR'

[Bug modula2/109952] New: Inconsistent HIGH values with 'ARRAY OF CHAR'

[gaius at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109952

            Bug ID: 109952
           Summary: Inconsistent HIGH values with 'ARRAY OF CHAR'
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: modula2
          Assignee: gaius at gcc dot gnu.org
          Reporter: gaius at gcc dot gnu.org
  Target Milestone: ---

As reported on the gm2 mailing list the behaviour of HIGH is inconsistent.

MODULE port_test8_gm2;

FROM IOChan IMPORT
  ChanId;
FROM StdChans IMPORT
  StdOutChan;
FROM Strings IMPORT
  Length;
FROM TextIO IMPORT
  WriteLn, WriteString;
FROM WholeIO IMPORT
  WriteCard;


VAR
  str_a:                        ARRAY[0..0] OF CHAR;
  str_b:                        ARRAY[0..1] OF CHAR;
  str_c:                        ARRAY[0..2] OF CHAR;


PROCEDURE ShowStringInfos(the_str: ARRAY OF CHAR);
  VAR
    cid_out:                    ChanId;

  BEGIN                         (* PROCEDURE ShowStringInfos *)
    cid_out:=StdOutChan();

    WriteString(cid_out, 'Length(the_str): ');
    WriteCard(cid_out, Length(the_str), 1);
    WriteLn(cid_out);

    WriteString(cid_out, 'HIGH(the_str): ');
    WriteCard(cid_out, HIGH(the_str), 1);
    WriteLn(cid_out);

    WriteString(cid_out, 'the_str: ');
    WriteString(cid_out, the_str);
    WriteLn(cid_out);

    WriteLn(cid_out);
  END ShowStringInfos;


BEGIN                           (* MODULE port_test8_gm2 *)
  ShowStringInfos('1');
  ShowStringInfos('12');
  ShowStringInfos('123');

  str_a:='a';
  ShowStringInfos(str_a);
  str_b:='ab';
  ShowStringInfos(str_b);
  str_c:='abc';
  ShowStringInfos(str_c);

  str_c:='d';
  ShowStringInfos(str_c);
END port_test8_gm2.

ShowStringInfos just prints out the Length, the HIGH value and the
string proper which is passed to the PROCEDURE. When using literals
'1', '12' and '123' the HIGH values are 0, 2 and 3.

[Bug modula2/109952] Inconsistent HIGH values with 'ARRAY OF CHAR'

[gaius at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109952

Gaius Mulley <gaius at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2023-05-24
             Status|UNCONFIRMED                 |ASSIGNED
     Ever confirmed|0                           |1

--- Comment #1 from Gaius Mulley <gaius at gcc dot gnu.org> ---
Confirmed - interestingly the standard is silent on nul termination of constant
string literals passed as an actual parameter to ARRAY OF CHAR.  But the
behaviour is certainly inconsistent and should be fixed.

[Bug modula2/109952] Inconsistent HIGH values with 'ARRAY OF CHAR'

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109952

--- Comment #2 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Gaius Mulley <gaius@gcc.gnu.org>:

https://gcc.gnu.org/g:b4df098647b687ca4e43952ec4a198b2816732ba

commit r14-1158-gb4df098647b687ca4e43952ec4a198b2816732ba
Author: Gaius Mulley <gaiusmod2@gmail.com>
Date:   Wed May 24 11:14:07 2023 +0100

    PR modula2/109952 Inconsistent HIGH values with 'ARRAY OF CHAR'

    This patch fixes the case when a single character constant literal is
    passed as a string actual parameter to an ARRAY OF CHAR formal parameter.
    To be consistent a single character is promoted to a string and nul
    terminated (and its high value is 1).  Previously a single character
    string would not be nul terminated and the high value was 0.
    The documentation now includes a section describing the expected behavior
    and included in this patch is some regression test code matching the
    table inside the documentation.

    gcc/ChangeLog:

            PR modula2/109952
            * doc/gm2.texi (High procedure function): New node.
            (Using): New menu entry for High procedure function.

    gcc/m2/ChangeLog:

            PR modula2/109952
            * Make-maintainer.in: Change header to include emacs file mode.
            * gm2-compiler/M2GenGCC.mod (BuildHighFromChar): Check whether
            operand is a constant string and is nul terminated then return one.
            * gm2-compiler/PCSymBuild.mod (WalkFunction): Add default return
            TRUE.  Static analysis missing return path fix.
            * gm2-libs/IO.mod (Init): Rewrite to help static analysis.
            * target-independent/m2/gm2-libs.texi: Rebuild.

    gcc/testsuite/ChangeLog:

            PR modula2/109952
            * gm2/pim/run/pass/hightests.mod: New test.

    Signed-off-by: Gaius Mulley <gaiusmod2@gmail.com>

[Bug modula2/109952] Inconsistent HIGH values with 'ARRAY OF CHAR'

[gaius at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109952

Gaius Mulley <gaius at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
             Status|ASSIGNED                    |RESOLVED

--- Comment #3 from Gaius Mulley <gaius at gcc dot gnu.org> ---
Closing as patch has been applied.

[Bug modula2/109952] Inconsistent HIGH values with 'ARRAY OF CHAR'

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109952

--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Eric Botcazou <ebotcazou@gcc.gnu.org>:

https://gcc.gnu.org/g:e8d41e031b9f52601249ec7e4c4215b851cc8ffe

commit r14-1710-ge8d41e031b9f52601249ec7e4c4215b851cc8ffe
Author: Eric Botcazou <ebotcazou@adacore.com>
Date:   Mon Jun 12 11:34:38 2023 +0200

    Fix oversight in latest change

    gcc/
            PR modula2/109952
            * doc/gm2.texi (Standard procedures): Fix Next link.

[Bug modula2/109952] Inconsistent HIGH values with 'ARRAY OF CHAR'

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109952

--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-13 branch has been updated by Gaius Mulley
<gaius@gcc.gnu.org>:

https://gcc.gnu.org/g:6ae50730003862aee81ad6c53e4c1a96ed1ee36e

commit r13-7640-g6ae50730003862aee81ad6c53e4c1a96ed1ee36e
Author: Gaius Mulley <gaiusmod2@gmail.com>
Date:   Sat Jul 29 04:13:34 2023 +0100

    PR modula2/109952 Inconsistent HIGH values with 'ARRAY OF CHAR'

    This patch fixes the case when a single character constant literal is
    passed as a string actual parameter to an ARRAY OF CHAR formal parameter.
    To be consistent a single character is promoted to a string and nul
    terminated (and its high value is 1).  Previously a single character
    string would not be nul terminated and the high value was 0.
    The documentation now includes a section describing the expected behavior
    and included in this patch is some regression test code matching the
    table inside the documentation.

    gcc/ChangeLog:

            PR modula2/109952
            * doc/gm2.texi (High procedure function): New node.
            (Using): New menu entry for High procedure function.

    gcc/m2/ChangeLog:

            PR modula2/109952
            * Make-maintainer.in: Change header to include emacs file mode.
            * gm2-compiler/M2GenGCC.mod (BuildHighFromChar): Check whether
            operand is a constant string and is nul terminated then return one.
            * gm2-compiler/PCSymBuild.mod (WalkFunction): Add default return
            TRUE.  Static analysis missing return path fix.
            * gm2-libs/IO.mod (Init): Rewrite to help static analysis.
            * target-independent/m2/gm2-libs.texi: Rebuild.

    gcc/testsuite/ChangeLog:

            PR modula2/109952
            * gm2/pim/run/pass/hightests.mod: New test.

    (cherry picked from commit b4df098647b687ca4e43952ec4a198b2816732ba)

    Signed-off-by: Gaius Mulley <gaiusmod2@gmail.com>

[Bug modula2/109952] Inconsistent HIGH values with 'ARRAY OF CHAR'

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109952

--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-13 branch has been updated by Gaius Mulley
<gaius@gcc.gnu.org>:

https://gcc.gnu.org/g:b555f824d6b6f2ab759f57098a7b4b3b47470c64

commit r13-7645-gb555f824d6b6f2ab759f57098a7b4b3b47470c64
Author: Gaius Mulley <gaiusmod2@gmail.com>
Date:   Sat Jul 29 17:33:28 2023 +0100

    PR modula2/109952 Fix oversight in latest change

    gcc/
            PR modula2/109952
            * doc/gm2.texi (Standard procedures): Fix Next link.

    (cherry picked from commit e8d41e031b9f52601249ec7e4c4215b851cc8ffe)

    Signed-off-by: Gaius Mulley <gaiusmod2@gmail.com>