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Re: [PATCH] PR fortran/78618 -- RANK() should not ICE
2016-12-02 17:30 GMT+01:00 Steve Kargl <sgk@troutmask.apl.washington.edu>:
> On Fri, Dec 02, 2016 at 04:47:19PM +0100, Janus Weil wrote:
>> Hi Steve,
>>
>> 2016-12-02 2:33 GMT+01:00 Steve Kargl <sgk@troutmask.apl.washington.edu>:
>> > The attached patch fixes an ICE, a nearby whitespace issue, and
>> > removed the ATTRIBUTE_UNUSED tag. THe change has passed regression
>> > testing on x86_64-*-freebsd. Ok to commit?
>>
>> huh, I don't really understand why the argument of RANK is detected to
>> be an EXPR_FUNCTION for the test case at hand. Shouldn't it rather be
>> an EXPR_CONSTANT?
>>
>> Some debugging in gfc_check_rank shows that a->symtree->n.sym indeed
>> is the symbol "c" (as expected), but that clearly is not a function,
>> so it seems to me that the actual bug here is that a->expr_type is set
>> incorrectly ...?
>
> I found that it is the function __convert_s4_s1.
That's strange. If we see different things here, maybe we are running
into some kind of undefined behavior (possibly related to
gfc_bad_expr?). Anyway, after some more debugging I came to the
conclusion that what actually fails is the error propagation, which
seems to be broken in gfc_check_assign and can be fixed like this:
Index: gcc/fortran/expr.c
===================================================================
--- gcc/fortran/expr.c (revision 243194)
+++ gcc/fortran/expr.c (working copy)
@@ -3314,9 +3314,9 @@ gfc_check_assign (gfc_expr *lvalue, gfc_expr *rval
if (lvalue->ts.type == BT_CHARACTER && rvalue->ts.type == BT_CHARACTER)
{
if (lvalue->ts.kind != rvalue->ts.kind && allow_convert)
- gfc_convert_chartype (rvalue, &lvalue->ts);
-
- return true;
+ return gfc_convert_chartype (rvalue, &lvalue->ts);
+ else
+ return true;
}
if (!allow_convert)
This also avoids the ICE and I think is the proper way to fix this ...
Cheers,
Janus