| Message ID | CAGkQGiLrFm8oD5PXoxZB+bEK6GLzm50Zwykg_dMqorcovnVmYg@mail.gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [fortran] PRs 96100 and 96101 - Problems with string lengths of array constructors | expand |
Hi Paul, > The fix for PR9601 is rather trivial and is the last chunk of the patch. > Finding the fix for PR96100 took a silly amount of time but it now looks > rather obvious. Trying to evaluate the string length by calling > gfc_conv_expr_descriptor, when this function is already failing to find it > is kind of doomed to failure :-) Therefore, gfc_conv_expr is used with > tse.descriptor_only set. This has the effect of ignoring trailing array > references and making use of gfc_conv_component_ref's being able to extract > the hidden string length for deferred length components. Finally, the > string length of the first element in the array constructor is set if this > is a deferred length component. The patch seems to be effective. Albeit I don't understand why, when it is a parenthesis op, you deduce that this has to be the string length? The explanation for the second fix left me completely lost. > Regtests OK on FC31/x86_64 - OK for master? Tests ok with no regression. Therefore ok by me. Regards, Andre > > Paul > > This patch fixes PR96100 and PR96101 by making some minor changes to > the evaluation of string lengths for gfc_conv_expr_descriptor. > > 2020-08-13 Paul Thomas <pault@gcc.gnu.org> > > gcc/fortran > PR fortran/96100 > PR fortran/96101 > * trans-array.c (get_array_charlen): Tidy up the evaluation of > the string length for array constructors. Avoid trailing array > references. Ensure string lengths of deferred length components > are set. For parentheses operator apply string length to both > the primary expression and the enclosed expression. > > gcc/testsuite/ > PR fortran/96100 > PR fortran/96101 > * gfortran.dg/char_length_23.f90: New test. -- Andre Vehreschild * Email: vehre ad gmx dot de
diff --git a/gcc/fortran/trans-array.c b/gcc/fortran/trans-array.c index 8f93b43bafb..ad3286487e8 100644 --- a/gcc/fortran/trans-array.c +++ b/gcc/fortran/trans-array.c @@ -7018,7 +7018,12 @@ get_array_charlen (gfc_expr *expr, gfc_se *se) e = gfc_constructor_first (expr->value.constructor)->expr; gfc_init_se (&tse, NULL); + + /* Avoid evaluating trailing array references since all we need is + the string length. */ if (e->rank) + tse.descriptor_only = 1; + if (e->rank && e->expr_type != EXPR_VARIABLE) gfc_conv_expr_descriptor (&tse, e); else gfc_conv_expr (&tse, e); @@ -7036,14 +7041,26 @@ get_array_charlen (gfc_expr *expr, gfc_se *se) gfc_add_modify (&se->pre, expr->ts.u.cl->backend_decl, tse.string_length); + /* Make sure that deferred length components point to the hidden + string_length component. */ + if (TREE_CODE (tse.expr) == COMPONENT_REF + && TREE_CODE (tse.string_length) == COMPONENT_REF + && TREE_OPERAND (tse.expr, 0) == TREE_OPERAND (tse.string_length, 0)) + e->ts.u.cl->backend_decl = expr->ts.u.cl->backend_decl; + return; case EXPR_OP: get_array_charlen (expr->value.op.op1, se); - /* For parentheses the expression ts.u.cl is identical. */ + /* For parentheses the expression ts.u.cl should be identical. */ if (expr->value.op.op == INTRINSIC_PARENTHESES) - return; + { + if (expr->value.op.op1->ts.u.cl != expr->ts.u.cl) + expr->ts.u.cl->backend_decl + = expr->value.op.op1->ts.u.cl->backend_decl; + return; + } expr->ts.u.cl->backend_decl = gfc_create_var (gfc_charlen_type_node, "sln");