[Bug modula2/112946] New: Assignment of string to enumeration or set crashes

[Bug modula2/112946] New: Assignment of string to enumeration or set crashes

[juriad at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112946

            Bug ID: 112946
           Summary: Assignment of string to enumeration or set crashes
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: modula2
          Assignee: gaius at gcc dot gnu.org
          Reporter: juriad at gmail dot com
  Target Milestone: ---

Created attachment 56846
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=56846&action=edit
reproducer + gcc crash output + crash report

I am playing with Modula-2 (due to Advent of Code). I compiled GCC from master
branch (fbfe43daec6443978df65530dc5f7f3f8a4e6f9e).

The attached program crashes when compiling (the error differs between strings
of length 1 and 2):

gm2 -freport-bug -fiso -static-libgm2 -o prg bug.mod

The full output is attached as well as the referenced report from /tmp/:

cc1gm2: internal compiler error: tree check: expected integer_cst, have
string_cst in get_len, at tree.h:6473

The expected behavior would be to show the error as usual with highlighted line
and explanation.

Apart from this crash, I encountered one more issue which may not be an error
(no idea; I have less than 1 day of experience with Modula) but would deserve
at least a warning. Arithmetic between set and enumeration does not produce
what I would expect.

DIRS := Dirs{Left, Right};
DIRS := DIRS + Up;
IF NOT (Up IN DIRS) THEN
        HALT
END;

On the other hand:

DIRS := Dirs{Left, Right} + Up;

leads to another crash:

cc1gm2: internal compiler error: expecting type of constant to be a set

[Bug modula2/112946] Assignment of string to enumeration or set crashes

[gaius at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112946

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2023-12-12
             Status|UNCONFIRMED                 |ASSIGNED

--- Comment #1 from Gaius Mulley <gaius at gcc dot gnu.org> ---
Confirmed - many thanks for  the bug report and test code!

[Bug modula2/112946] Assignment of string to enumeration or set crashes

[gaius at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112946

--- Comment #2 from Gaius Mulley <gaius at gcc dot gnu.org> ---
Created attachment 56886
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=56886&action=edit
Proposed fix

Here is the proposed fix.

[Bug modula2/112946] Assignment of string to enumeration or set crashes

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112946

--- Comment #3 from GCC 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:7d7a480eedf0a195318d0fce2c9c57acae43ec9d

commit r14-6596-g7d7a480eedf0a195318d0fce2c9c57acae43ec9d
Author: Gaius Mulley <gaiusmod2@gmail.com>
Date:   Fri Dec 15 15:26:48 2023 +0000

    PR modula2/112946 ICE assignment of string to enumeration or set

    This patch introduces type checking during FoldBecomes and also
    adds set/string/enum checking to the type checker.  FoldBecomes
    has been re-written, tidied up and re-factored.

    gcc/m2/ChangeLog:

            PR modula2/112946
            * gm2-compiler/M2Check.mod (checkConstMeta): New procedure
            function.
            (checkConstEquivalence): New procedure function.
            (doCheckPair): Add call to checkConstEquivalence.
            * gm2-compiler/M2GenGCC.mod (ResolveConstantExpressions): Call
            FoldBecomes with reduced parameters.
            (FoldBecomes): Re-write.
            (TryDeclareConst): New procedure.
            (RemoveQuads): New procedure.
            (DeclaredOperandsBecomes): New procedure function.
            (TypeCheckBecomes): New procedure function.
            (PerformFoldBecomes): New procedure.
            * gm2-compiler/M2Range.mod (FoldAssignment): Call
            AssignmentTypeCompatible to check des expr compatibility.
            * gm2-compiler/M2SymInit.mod (CheckReadBeforeInitQuad): Remove
            parameter lst.
            (FilterCheckReadBeforeInitQuad): Remove parameter lst.
            (CheckReadBeforeInitFirstBasicBlock): Remove parameter lst.
            Call FilterCheckReadBeforeInitQuad without lst.

    gcc/testsuite/ChangeLog:

            PR modula2/112946
            * gm2/iso/fail/badassignment.mod: New test.
            * gm2/iso/fail/badexpression.mod: New test.
            * gm2/iso/fail/badexpression2.mod: New test.

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

[Bug modula2/112946] Assignment of string to enumeration or set crashes

[gaius at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112946

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

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

--- Comment #4 from Gaius Mulley <gaius at gcc dot gnu.org> ---
Closing now the patch has been applied.

[Bug modula2/112946] Assignment of string to enumeration or set crashes

[gaiusmod2 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112946

--- Comment #5 from gaiusmod2 at gmail dot com ---
many thanks for the bug report - all fixed in gcc master branch.

[Bug modula2/112946] Assignment of string to enumeration or set crashes

[gaius at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112946

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

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

--- Comment #6 from Gaius Mulley <gaius at gcc dot gnu.org> ---
MODULE badexpression3 ;

TYPE
   enums = (red, blue, green) ;
   set = SET OF enums ;
VAR
   setvar : set;
   enumvar: enums;
BEGIN
   setvar := set {red, blue} ;
   setvar := setvar + green ;    (* Should detect an error here.  *)
   IF NOT (green IN setvar)
   THEN
      HALT
   END
END badexpression3.

successfully compiles - and it should detect an error at "setvar + green".
M2GenGCC.mod:FoldBinary (and FoldUnary) need the same treatment as FoldBecomes
in the original patch.

[Bug modula2/112946] Assignment of string to enumeration or set crashes

[gaius at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112946

--- Comment #7 from Gaius Mulley <gaius at gcc dot gnu.org> ---
Created attachment 57025
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=57025&action=edit
Proposed fix v2

The proposed patch fixes the expression type mismatch case presented above.  It
also fixes a number of related expression (foo IN setval) and all binary sets
arithmetic is checked and virtual tokens are used to highlight sub expressions
in error.

[Bug modula2/112946] Assignment of string to enumeration or set crashes

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112946

--- Comment #8 from GCC 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:96a9355a3d5b24f010fa6ad0b51bba5cc3f334f1

commit r14-7123-g96a9355a3d5b24f010fa6ad0b51bba5cc3f334f1
Author: Gaius Mulley <gaiusmod2@gmail.com>
Date:   Thu Jan 11 00:53:56 2024 +0000

    PR modula2/112946 set expression type checking

    This patch adds type checking for binary set operators.
    It also checks the IN operator and improves the := type checking.

    gcc/m2/ChangeLog:

            PR modula2/112946
            * gm2-compiler/M2GenGCC.mod (IsExpressionCompatible): Import.
            (ExpressionTypeCompatible): Import.
            (CodeStatement): Remove op1, op2, op3 parameters from CodeSetOr,
            CodeSetAnd, CodeSetSymmetricDifference, CodeSetLogicalDifference.
            (checkArrayElements): Rename op1 to des and op3 to expr.
            Use despos and exprpos instead of CurrentQuadToken.
            (checkRecordTypes): Rename op1 to des and op2 to expr.
            Use virtpos instead of CurrentQuadToken.
            (checkIncorrectMeta): Ditto.
            (checkBecomes): Rename op1 to des and op3 to expr.
            Use virtpos instead of CurrentQuadToken.
            (NoWalkProcedure): New procedure stub.
            (CheckBinaryExpressionTypes): New procedure function.
            (CheckElementSetTypes): New procedure function.
            (CodeBinarySet): Re-write.
            (FoldBinarySet): Re-write.
            (CodeSetOr): Remove parameters op1, op2 and op3.
            (CodeSetAnd): Ditto.
            (CodeSetLogicalDifference): Ditto.
            (CodeSetSymmetricDifference): Ditto.
            (CodeIfIn): Call CheckBinaryExpressionTypes and
            CheckElementSetTypes.
            * gm2-compiler/M2Quads.mod (BuildRotateFunction): Correct
            parameters to MakeVirtualTok to reflect parameter block
            passed to Rotate.

    gcc/testsuite/ChangeLog:

            PR modula2/112946
            * gm2/pim/fail/badbecomes.mod: New test.
            * gm2/pim/fail/badexpression.mod: New test.
            * gm2/pim/fail/badexpression2.mod: New test.
            * gm2/pim/fail/badifin.mod: New test.
            * gm2/pim/pass/goodifin.mod: New test.

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

[Bug modula2/112946] Assignment of string to enumeration or set crashes

[gaius at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112946

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

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

--- Comment #9 from Gaius Mulley <gaius at gcc dot gnu.org> ---
Closing now that the patch has been applied.