c-decl.c (start_struct): Ensure that structs with forward declarations are in fact packed when...

* c-decl.c (start_struct): Ensure that structs with forward
        declarations are in fact packed when -fpack-struct is given.

        * stor-layout.c (layout_record): Ignore STRUCTURE_SIZE_BOUNDARY if
        we are packing a structure.  This allows a structure with only
        bytes to be aligned on a byte boundary and have no padding on a
        m68k.

From-SVN: r15939
This commit is contained in:
Mike Stump 1997-10-16 21:45:24 +00:00 committed by Jeff Law
parent bdd7e652f4
commit 5c19a35643
3 changed files with 22 additions and 8 deletions

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@ -1,3 +1,13 @@
Thu Oct 16 15:43:26 1997 Mike Stump (mrs@wrs.com)
* c-decl.c (start_struct): Ensure that structs with forward
declarations are in fact packed when -fpack-struct is given.
* stor-layout.c (layout_record): Ignore STRUCTURE_SIZE_BOUNDARY if
we are packing a structure. This allows a structure with only
bytes to be aligned on a byte boundary and have no padding on a
m68k.
Thu Oct 16 15:17:54 1997 Richard Kenner <kenner@vlsi1.ultra.nyu.edu>
* rs6000.h (ROUND_TYPE_ALIGN): Don't blow up if no fields in record.

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@ -5529,6 +5529,7 @@ start_struct (code, name)
if (ref && TREE_CODE (ref) == code)
{
C_TYPE_BEING_DEFINED (ref) = 1;
TYPE_PACKED (ref) = flag_pack_struct;
if (TYPE_FIELDS (ref))
error ((code == UNION_TYPE ? "redefinition of `union %s'"
: "redefinition of `struct %s'"),

View File

@ -306,11 +306,7 @@ layout_record (rec)
tree rec;
{
register tree field;
#ifdef STRUCTURE_SIZE_BOUNDARY
unsigned record_align = MAX (STRUCTURE_SIZE_BOUNDARY, TYPE_ALIGN (rec));
#else
unsigned record_align = MAX (BITS_PER_UNIT, TYPE_ALIGN (rec));
#endif
/* These must be laid out *after* the record is. */
tree pending_statics = NULL_TREE;
/* Record size so far is CONST_SIZE + VAR_SIZE bits,
@ -324,6 +320,11 @@ layout_record (rec)
that we know VAR_SIZE has. */
register int var_align = BITS_PER_UNIT;
#ifdef STRUCTURE_SIZE_BOUNDARY
/* Packed structures don't need to have minimum size. */
if (! TYPE_PACKED (rec))
record_align = MAX (record_align, STRUCTURE_SIZE_BOUNDARY);
#endif
for (field = TYPE_FIELDS (rec); field; field = TREE_CHAIN (field))
{
@ -563,11 +564,7 @@ layout_union (rec)
tree rec;
{
register tree field;
#ifdef STRUCTURE_SIZE_BOUNDARY
unsigned union_align = STRUCTURE_SIZE_BOUNDARY;
#else
unsigned union_align = BITS_PER_UNIT;
#endif
/* The size of the union, based on the fields scanned so far,
is max (CONST_SIZE, VAR_SIZE).
@ -575,6 +572,12 @@ layout_union (rec)
register int const_size = 0;
register tree var_size = 0;
#ifdef STRUCTURE_SIZE_BOUNDARY
/* Packed structures don't need to have minimum size. */
if (! TYPE_PACKED (rec))
union_align = STRUCTURE_SIZE_BOUNDARY;
#endif
/* If this is a QUAL_UNION_TYPE, we want to process the fields in
the reverse order in building the COND_EXPR that denotes its
size. We reverse them again later. */