Dear all,
with the following change in 4.5, the -Walign-commons warning got disabled:
"The |COMMON| default padding has been changed – instead of adding the
padding before a variable it is now added afterwards, which increases
the compatibility with other vendors and helps to obtain the correct
output in some cases."
The attached patch restores the warning. I actually got a bit lost
tracking the offset (and the "max_align" usage), hence, I wouldn't mind
a careful review. However, testing didn't show any alignment issues.
Build and regtested (trunk) on x86-64-linux.
Ok for the trunk, 4.6 and 4.5?
Tobias
2011-09-30 Tobias Burnus <bur...@net-b.de>
PR fortran/45044
* trans-common.c (translate_common): Fix -Walign-commons
check.
2011-09-30 Tobias Burnus <bur...@net-b.de>
PR fortran/45044
* gfortran.dg/common_14.f90: Compile with -Wno-align-commons.
* gfortran.dg/common_16.f90: New.
diff --git a/gcc/fortran/trans-common.c b/gcc/fortran/trans-common.c
index 21237c8..61ce44b 100644
--- a/gcc/fortran/trans-common.c
+++ b/gcc/fortran/trans-common.c
@@ -1067,14 +1067,12 @@ translate_common (gfc_common_head *common, gfc_symbol *var_list)
HOST_WIDE_INT offset;
HOST_WIDE_INT current_offset;
unsigned HOST_WIDE_INT align;
- unsigned HOST_WIDE_INT max_align;
bool saw_equiv;
common_segment = NULL;
offset = 0;
current_offset = 0;
align = 1;
- max_align = 1;
saw_equiv = false;
/* Add symbols to the segment. */
@@ -1117,7 +1115,7 @@ translate_common (gfc_common_head *common, gfc_symbol *var_list)
if (gfc_option.flag_align_commons)
offset = align_segment (&align);
- if (offset & (max_align - 1))
+ if (offset)
{
/* The required offset conflicts with previous alignment
requirements. Insert padding immediately before this
@@ -1140,8 +1138,6 @@ translate_common (gfc_common_head *common, gfc_symbol *var_list)
/* Apply the offset to the new segments. */
apply_segment_offset (current_segment, offset);
current_offset += offset;
- if (max_align < align)
- max_align = align;
/* Add the new segments to the common block. */
common_segment = add_segments (common_segment, current_segment);
@@ -1161,11 +1157,11 @@ translate_common (gfc_common_head *common, gfc_symbol *var_list)
if (common_segment->offset != 0 && gfc_option.warn_align_commons)
{
if (strcmp (common->name, BLANK_COMMON_NAME))
- gfc_warning ("COMMON '%s' at %L requires %d bytes of padding at start; "
+ gfc_warning ("COMMON '%s' at %L requires %d bytes of padding; "
"reorder elements or use -fno-align-commons",
common->name, &common->where, (int)common_segment->offset);
else
- gfc_warning ("COMMON at %L requires %d bytes of padding at start; "
+ gfc_warning ("COMMON at %L requires %d bytes of padding; "
"reorder elements or use -fno-align-commons",
&common->where, (int)common_segment->offset);
}
diff --git a/gcc/testsuite/gfortran.dg/common_14.f90 b/gcc/testsuite/gfortran.dg/common_14.f90
index aced168..892e4a5 100644
--- a/gcc/testsuite/gfortran.dg/common_14.f90
+++ b/gcc/testsuite/gfortran.dg/common_14.f90
@@ -1,4 +1,5 @@
! { dg-do compile }
+! { dg-options "-Wno-align-commons" }
!
! PR fortran/45044
!
--- /dev/null 2011-09-29 19:34:44.523522036 +0200
+++ gcc/gcc/testsuite/gfortran.dg/common_16.f90 2011-09-30 09:23:54.000000000 +0200
@@ -0,0 +1,12 @@
+! { dg-do compile }
+! { dg-options "-pedantic -mdalign" { target sh*-*-* } }
+!
+! PR fortran/50273
+!
+subroutine test()
+ character :: a
+ integer :: b
+ character :: c
+ common /global_var/ a, b, c ! { dg-warning "Padding of 3 bytes required before 'b' in COMMON" }
+ print *, a, b, c
+end subroutine test
