Named common blocks are required to have the same size in all files and
scopes. gfortran was warning before when the size was extended, but not
when a smaller common block followed a larger common block with the same
name.
This patch adds now a non-equal check and also mentions the byte size. I
was thinking of adding another ref to point to the first common block,
but my approach did not work (cf. PR comment 4) - besides, I find error
messages with two loci harder to read.
Build and regtested on x86-64-linux.
OK for the trunk?
Tobias
2011-08-30 Tobias Burnus <bur...@net-b.de>
PR fortran/45044
* trans-common.c (build_common_decl): Warn if named common
block's size is not everywhere the same.
2011-08-30 Tobias Burnus <bur...@net-b.de>
PR fortran/45044
* gfortran.dg/common_14.f90: New.
diff --git a/gcc/fortran/trans-common.c b/gcc/fortran/trans-common.c
index c289bbe..21237c8 100644
--- a/gcc/fortran/trans-common.c
+++ b/gcc/fortran/trans-common.c
@@ -390,14 +390,20 @@ build_common_decl (gfc_common_head *com, tree union_type, bool is_init)
if (decl != NULL_TREE)
{
tree size = TYPE_SIZE_UNIT (union_type);
+
+ /* Named common blocks of the same name shall be of the same size
+ in all scoping units of a program in which they appear, but
+ blank common blocks may be of different sizes. */
+ if (!tree_int_cst_equal (DECL_SIZE_UNIT (decl), size)
+ && strcmp (com->name, BLANK_COMMON_NAME))
+ gfc_warning ("Named COMMON block '%s' at %L shall be of the "
+ "same size as elsewhere (%lu vs %lu bytes)", com->name,
+ &com->where,
+ (unsigned long) TREE_INT_CST_LOW (size),
+ (unsigned long) TREE_INT_CST_LOW (DECL_SIZE_UNIT (decl)));
+
if (tree_int_cst_lt (DECL_SIZE_UNIT (decl), size))
- {
- /* Named common blocks of the same name shall be of the same size
- in all scoping units of a program in which they appear, but
- blank common blocks may be of different sizes. */
- if (strcmp (com->name, BLANK_COMMON_NAME))
- gfc_warning ("Named COMMON block '%s' at %L shall be of the "
- "same size", com->name, &com->where);
+ {
DECL_SIZE (decl) = TYPE_SIZE (union_type);
DECL_SIZE_UNIT (decl) = size;
DECL_MODE (decl) = TYPE_MODE (union_type);
--- /dev/null 2011-08-26 08:04:10.762940730 +0200
+++ gcc/gcc/testsuite/gfortran.dg/common_14.f90 2011-08-30 23:25:14.000000000 +0200
@@ -0,0 +1,27 @@
+! { dg-do compile }
+!
+! PR fortran/45044
+!
+! Named common blocks need to be all of the same size
+! check that the compiler warns for those.
+
+module m
+ common /xx/ a
+end module m
+
+subroutine two()
+integer :: a, b, c
+real(8) :: y
+common /xx/ a, b, c, y ! { dg-warning "Named COMMON block 'xx' at \\(1\\) shall be of the same size as elsewhere \\(24 vs 4 bytes" }
+end
+
+
+subroutine one()
+integer :: a, b
+common /xx/ a, b ! { dg-warning "Named COMMON block 'xx' at \\(1\\) shall be of the same size as elsewhere \\(8 vs 24 bytes" }
+end
+
+call two()
+end
+
+! { dg-final { cleanup-modules "m" } }
