[Bug d/96153] d: struct literals have non-deterministic hash values

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96153

--- Comment #1 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Iain Buclaw <ibuc...@gcc.gnu.org>:

https://gcc.gnu.org/g:2ac51bdf63b0e17d1b9974f30303fb24e3cbc83d

commit r11-2548-g2ac51bdf63b0e17d1b9974f30303fb24e3cbc83d
Author: Iain Buclaw <ibuc...@gdcproject.org>
Date:   Wed Jul 22 09:50:38 2020 +0200

    d: Fix struct literals that have non-deterministic hash values (PR96153)

    Adds code generation for generating a temporary for, and pre-filling
    struct and array literals with zeroes before assigning, so that
    alignment holes don't cause objects to produce a non-deterministic hash
    value.  A new field has been added to the expression visitor to track
    whether the result is being generated for another literal, so that
    memset() is only called once on the top-level literal expression, and
    not for nesting struct or arrays.

    gcc/d/ChangeLog:

            PR d/96153
            * d-tree.h (build_expr): Add literalp argument.
            * expr.cc (ExprVisitor): Add literalp_ field.
            (ExprVisitor::ExprVisitor): Initialize literalp_.
            (ExprVisitor::visit (AssignExp *)): Call memset() on blits where
RHS
            is a struct literal.  Elide assignment if initializer is all
zeroes.
            (ExprVisitor::visit (CastExp *)): Forward literalp_ to generation
of
            subexpression.
            (ExprVisitor::visit (AddrExp *)): Likewise.
            (ExprVisitor::visit (ArrayLiteralExp *)): Use memset() to pre-fill
            object with zeroes.  Set literalp in subexpressions.
            (ExprVisitor::visit (StructLiteralExp *)): Likewise.
            (ExprVisitor::visit (TupleExp *)): Set literalp in subexpressions.
            (ExprVisitor::visit (VectorExp *)): Likewise.
            (ExprVisitor::visit (VectorArrayExp *)): Likewise.
            (build_expr): Forward literal_p to ExprVisitor.

    gcc/testsuite/ChangeLog:

            PR d/96153
            * gdc.dg/pr96153.d: New test.