https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89492
--- Comment #3 from Harald Anlauf <anlauf at gmx dot de> ---
I found another issue for uses of transfer('',['']), so here's an updated
version with a clearer error message:
Index: gcc/fortran/check.c
===================================================================
--- gcc/fortran/check.c (revision 269177)
+++ gcc/fortran/check.c (working copy)
@@ -5487,6 +5487,26 @@
if (!gfc_element_size (mold, &result_elt_size))
return false;
+ if (result_elt_size == 0 && *source_size > 0)
+ {
+ gfc_error ("%<MOLD%> argument of %<TRANSFER%> intrinsic at %L "
+ "shall not have storage size 0 when %<SOURCE%> "
+ "argument has size greater than 0", &mold->where);
+ return false;
+ }
+
+ /* If MOLD is a scalar and SIZE is absent, the result is a scalar.
+ * If MOLD is an array and SIZE is absent, the result is an array and of
+ * rank one. Its size is as small as possible such that its physical
+ * representation is not shorter than that of SOURCE.
+ */
+ if (result_elt_size == 0 && *source_size == 0 && !size)
+ {
+ *result_size = 0;
+ *result_length_p = 0;
+ return true;
+ }
+
if ((result_elt_size > 0 && (mold->expr_type == EXPR_ARRAY || mold->rank))
|| size)
{
Suggested testcase:
! { dg-do compile }
!
! PR fortran/89492 - Endless compilation of an invalid TRANSFER after r269177
! Test error recovery for invalid uses of TRANSFER
! Test proper simplification for MOLD with size 0
!
! Derived from original testcase by Dominique d'Humieres
program bug4a
implicit none
type bug4
! Intentionally left empty
end type bug4
integer, parameter :: k = size(transfer('',[''])) ! k = 0
integer, parameter :: m(k) = k
print *, transfer(1,['']) ! { dg-error "shall not have
storage size 0" }
print *, size(transfer(1,[''])) ! { dg-error "shall not have
storage size 0" }
print *, size(transfer([1],[bug4()])) ! { dg-error "shall not have
storage size 0" }
print *, transfer(transfer([1],[bug4()]),[1]) ! { dg-error "shall not have
storage size 0" }
end program bug4a
