[Bug modula2/113889] New: Incorrect constant string value if declared in a definition module

[Bug modula2/113889] New: Incorrect constant string value if declared in a definition module

[gaius at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113889

            Bug ID: 113889
           Summary: Incorrect constant string value if declared in a
                    definition module
           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.  Constant strings are not handled
correctly if they are exported from a definition module (and appear as a nul
string).

DEFINITION MODULE Foo;

  CONST Bar = "Blech";

END Foo.

IMPLEMENTATION MODULE Foo;
END Foo.

MODULE test_foo;

  IMPORT Foo;

  FROM STextIO IMPORT WriteString, WriteLn;
  FROM Foo     IMPORT Bar;

BEGIN
  WriteString("Bar => ");
  WriteString(Foo.Bar);
  WriteLn;

  WriteString("Bar => ");
  WriteString(Bar);
  WriteLn;
END test_foo.

At test program run time, Bar becomes an empty string, with the following 
result:

Bar =>
Bar =>

[Bug modula2/113889] Incorrect constant string value if declared in a definition module

[gaius at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113889

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2024-02-12
     Ever confirmed|0                           |1

--- Comment #1 from Gaius Mulley <gaius at gcc dot gnu.org> ---
Indeed - observed and reproduced.

[Bug modula2/113889] Incorrect constant string value if declared in a definition module

[gaius at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113889

--- Comment #2 from Gaius Mulley <gaius at gcc dot gnu.org> ---
Created attachment 57453
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=57453&action=edit
Proposed fix

Here is a proposed patch and associated testcases.

[Bug modula2/113889] Incorrect constant string value if declared in a definition module

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113889

--- 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:78b72ee5a80f45bd761a55006e2b3fc2cbe749bc

commit r14-9063-g78b72ee5a80f45bd761a55006e2b3fc2cbe749bc
Author: Gaius Mulley <gaiusmod2@gmail.com>
Date:   Mon Feb 19 12:59:36 2024 +0000

    PR modula2/113889 Incorrect constant string value if declared in a
definition module

    This patch fixes a bug exposed when a constant string is declared in a
    definition module and imported by a program module.  The bug fix
    was to defer the string assignment and concatenation until quadruples
    were generated.  The conststring symbol has a known field which
    must be checked prior to retrieving the string contents.

    gcc/m2/ChangeLog:

            PR modula2/113889
            * gm2-compiler/M2ALU.mod (StringFitsArray): Add tokeno parameter
            to GetStringLength.
            (InitialiseArrayOfCharWithString): Add tokeno parameter to
            GetStringLength.
            (CheckGetCharFromString): Add tokeno parameter to GetStringLength.
            * gm2-compiler/M2Const.mod (constResolveViaMeta): Replace
            PutConstString with PutConstStringKnown.
            * gm2-compiler/M2GCCDeclare.mod (DeclareCharConstant): Add tokenno
            parameter and add assert.  Use tokenno to generate location.
            (DeclareStringConstant): Add tokenno and add asserts.
            Add tokenno parameter to calls to GetStringLength.
            (PromoteToString): Add assert and add tokenno parameter to
            GetStringLength.
            (PromoteToCString): Add assert and add tokenno parameter to
            GetStringLength.
            (DeclareConstString): New procedure function.
            (TryDeclareConst): Remove size local variable.
            Check IsConstStringKnown.
            Call DeclareConstString.
            (PrintString): New procedure.
            (PrintVerboseFromList): Call PrintString.
            (CheckResolveSubrange): Check IsConstStringKnown before creating
            subrange for char or issuing an error.
            * gm2-compiler/M2GenGCC.mod (ResolveConstantExpressions): Add
            StringLengthOp, StringConvertM2nulOp, StringConvertCnulOp case
            clauses.
            (FindSize): Add assert IsConstStringKnown.
            (StringToChar): New variable tokenno.
            Add tokenno parameter to GetStringLength.
            (FoldStringLength): New procedure.
            (FoldStringConvertM2nul): New procedure.
            (FoldStringConvertCnul): New procedure.
            (CodeAddr): Add tokenno parameter.
            Replace CurrentQuadToken with tokenno.
            Add tokenno parameter to GetStringLength.
            (PrepareCopyString): Rewrite.
            (IsConstStrKnown): New procedure function.
            (FoldAdd): Detect conststring op2 and op3 which are known and
            concat.  Place result into op1.
            (FoldStandardFunction): Pass tokenno as a parameter to
            GetStringLength.
            (CodeXIndr): Rewrite comment.
            Rename op1 to left, op3 to right.
            Pass rightpos to GetStringLength.
            * gm2-compiler/M2Quads.def (QuadrupleOp): Add
            StringConvertCnulOp, StringConvertM2nulOp and StringLengthOp.
            * gm2-compiler/M2Quads.mod (import): Remove MakeConstLitString.
            Add CopyConstString and PutConstStringKnown.
            (IsInitialisingConst): Add StringConvertCnulOp,
            StringConvertM2nulOp and StringLengthOp.
            (callRequestDependant): Replace MakeConstLitString with
            MakeConstString.
            (DeferMakeConstStringCnul): New procedure function.
            (DeferMakeConstStringM2nul): New procedure function.
            (CheckParameter): Add early return if the string const is unknown.
            (DescribeType): Add token parameter to GetStringLength.
            Check for IsConstStringKnown.
            (ManipulateParameters): Use DeferMakeConstStringCnul and
            DeferMakeConstStringM2nul.
            (MakeLengthConst): Remove and replace with...
            (DeferMakeLengthConst): ... this.
            (doBuildBinaryOp): Create ConstString and set it to contents
            unknown.
            Check IsConstStringKnown before generating error message.
            (WriteQuad): Add StringConvertCnulOp, StringConvertM2nulOp and
            StringLengthOp.
            (WriteOperator): Add StringConvertCnulOp, StringConvertM2nulOp and
            StringLengthOp.
            * gm2-compiler/M2SymInit.mod (CheckReadBeforeInitQuad): Add
            StringConvertCnulOp, StringConvertM2nulOp and StringLengthOp.
            * gm2-compiler/NameKey.mod (LengthKey): Allow NulName to return 0.
            * gm2-compiler/P2SymBuild.mod (BuildString): Replace
            MakeConstLitString with MakeConstString.
            (DetermineType): Replace PutConstString with PutConstStringKnown.
            * gm2-compiler/SymbolTable.def (MakeConstVar): Tidy up comment.
            (MakeConstLitString): Remove.
            (MakeConstString): New procedure function.
            (MakeConstStringCnul): New procedure function.
            (MakeConstStringM2nul): New procedure function.
            (PutConstStringKnown): New procedure.
            (CopyConstString): New procedure.
            (IsConstStringKnown): New procedure function.
            (IsConstStringM2): New procedure function.
            (IsConstStringC): New procedure function.
            (IsConstStringM2nul): New procedure function.
            (IsConstStringCnul): New procedure function.
            (GetStringLength): Add token parameter.
            (PutConstString): Remove.
            (GetConstStringM2): Remove.
            (GetConstStringC): Remove.
            (GetConstStringM2nul): Remove.
            (GetConstStringCnul): Remove.
            (MakeConstStringC): Remove.
            * gm2-compiler/SymbolTable.mod (SymConstString): Remove
            M2Variant, NulM2Variant, CVariant, NulCVariant.
            Add Known.
            (CheckAnonymous): Replace $$ with __anon.
            (IsNameAnonymous): Replace $$ with __anon.
            (MakeConstVar): Detect whether the name is nul and treat as
            a temporary constant.
            (MakeConstLitString): Remove.
            (BackFillString): Remove.
            (InitConstString): Rewrite.
            (GetConstStringM2): Remove.
            (GetConstStringC): Remove.
            (GetConstStringContent): New procedure function.
            (GetConstStringM2nul): Remove.
            (GetConstStringCnul): Remove.
            (MakeConstStringCnul): Rewrite.
            (MakeConstStringM2nul): Rewrite.
            (MakeConstStringC): Remove.
            (MakeConstString): Rewrite.
            (PutConstStringKnown): New procedure.
            (CopyConstString): New procedure.
            (PutConstString): Remove.
            (IsConstStringKnown): New procedure function.
            (IsConstStringM2): New procedure function.
            (IsConstStringC): Rewrite.
            (IsConstStringM2nul): Rewrite.
            (IsConstStringCnul): Rewrite.
            (GetConstStringKind): New procedure function.
            (GetString): Check Known.
            (GetStringLength): Add token parameter and check Known.

    gcc/testsuite/ChangeLog:

            PR modula2/113889
            * gm2/pim/run/pass/pim-run-pass.exp: Add filter for
            constdef.mod.
            * gm2/extensions/run/pass/callingc2.mod: New test.
            * gm2/extensions/run/pass/callingc3.mod: New test.
            * gm2/extensions/run/pass/callingc4.mod: New test.
            * gm2/extensions/run/pass/callingc5.mod: New test.
            * gm2/extensions/run/pass/callingc6.mod: New test.
            * gm2/extensions/run/pass/callingc7.mod: New test.
            * gm2/extensions/run/pass/callingc8.mod: New test.
            * gm2/extensions/run/pass/fixedarray.mod: New test.
            * gm2/extensions/run/pass/fixedarray2.mod: New test.
            * gm2/pim/run/pass/constdef.def: New test.
            * gm2/pim/run/pass/constdef.mod: New test.
            * gm2/pim/run/pass/testimportconst.mod: New test.

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

[Bug modula2/113889] Incorrect constant string value if declared in a definition module

[gaius at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113889

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.