As PR 36471 shows, building libgfortran's Fortran parts with -fimplicit-none
can help detecting programming errors in the Fortran written parts of
libgfortran.
I suggest to use such a patch:
Index: configure.ac
===================================================================
--- configure.ac (Revision 136654)
+++ configure.ac (Arbeitskopie)
@@ -123,7 +123,7 @@ m4_rename([real_PRECIOUS],[_AC_ARG_VAR_P
# Add -Wall -fno-repack-arrays -fno-underscoring if we are using GCC.
if test "x$GCC" = "xyes"; then
- AM_FCFLAGS="-I . -Wall -fno-repack-arrays -fno-underscoring"
+ AM_FCFLAGS="-I . -Wall -Werror -fimplicit-none -fno-repack-arrays
-fno-underscoring"
## We like to use C99 routines when available. This makes sure that
## __STDC_VERSION__ is set such that libc includes make them available.
AM_CFLAGS="-std=gnu99 -Wall -Wstrict-prototypes -Wmissing-prototypes
-Wold-style-definition -Wextra -Wwrite-strings"
Index: intrinsics/dprod_r8.f90
===================================================================
--- intrinsics/dprod_r8.f90 (Revision 136654)
+++ intrinsics/dprod_r8.f90 (Arbeitskopie)
@@ -20,6 +20,7 @@
elemental function _gfortran_specific__dprod_r8 (p1, p2)
+ implicit none
real (kind=4), intent (in) :: p1, p2
real (kind=8) :: _gfortran_specific__dprod_r8
--
Summary: libgfortran should be build with FCFLAGS -fimplicit-none
Product: gcc
Version: 4.4.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: burnus at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36495
