[Issue 15261] New: [dmd-internal] Trivial problem in BinExp.checkOpAssignTypes

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=15261

          Issue ID: 15261
           Summary: [dmd-internal] Trivial problem in
                    BinExp.checkOpAssignTypes
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: minor
          Priority: P1
         Component: dmd
          Assignee: nobody at puremagic.com
          Reporter: k.hara.pg at gmail.com

In BinExp.checkOpAssignTypes:

    if (op == TOKmulass ||
        op == TOKdivass ||
        op == TOKmodass ||
        TOKaddass ||        // TOK enum is used as a boolean value!
        op == TOKminass ||
        op == TOKpowass)
    {
        if ((type.isintegral() && t2.isfloating()))
        {
            warning("%s %s %s is performing truncating conversion",
type.toChars(), Token.toChars(op), t2.toChars());
        }
    }

But this is not a real problem, because:

1. checkOpAssignTypes is called only from BinAssignExp.semantic

2. BinAssignExp.semantic is used by these concrete classes derived from
BinAssignExp:

   (Add|Min|Mul|Div|Mod|Pow)AssignExp
   (And|Or|Xor)AssignExp
   (Shl|Shr|Ushr)AssignExp

3. However, BinAssignExp.e2.type can have floating point type only in:

   (Add|Min|Mul|Div|Mod|Pow)AssignExp

   Other cases are rejected before the call of checkOpAssignTypes in
BinAssignExp.semantic.

   Test case (compile with -o- -w):

    void main()
    {
        int x;
        double y;

        x += y;     // AddAssignExp  -> warning, expected
        x -= y;     // MinAssignExp  -> warning, expected
        x *= y;     // MulAssignExp  -> warning, expected
        x /= y;     // DivAssignExp  -> warning, expected
        x %= y;     // ModAssignExp  -> warning, expected
        x ^^= y;    // PowAssignExp  -> warning, expected

        x &= y;     // AndAssignExp  -> error, does not reach to
checkOpAssignTypes call
        x |= y;     // OrAssignExp   -> error, ditto
        x ^= y;     // XorAssignExp  -> error, ditto
        x <<= y;    // ShlAssignExp  -> error, ditto
        x >>= y;    // ShrAssignExp  -> error, ditto
        x >>>= y;   // UshrAssignExp -> error, ditto
    }

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