+2004-05-17 Paul Eggert <eggert@cs.ucla.edu>
+
+ Port obstack to the AS/400, where pointers are 16 bytes wide and
+ you cannot cast an integer to a valid pointer. This patch is
+ currently waiting to be integrated into glibc; see
+ <http://sources.redhat.com/ml/libc-alpha/2004-05/msg00073.html>.
+
+ * obstack.h (__PTR_TO_INT, __INT_TO_PTR): Remove.
+ All uses of __INT_TO_PTR (PTR_TO_INT ...) replaced by __PTR_ALIGN.
+ (__BPTR_ALIGN, __PTR_ALIGN): New macros.
+ (struct obstack): temp member is now a union of a pointer and
+ an integer, instead of an integer. All integer uses changed.
+ This does not affect the physical layout of struct obstack,
+ except on hosts (like the AS/400) where the size or alignment of
+ void * is greater than that of ptrdiff_t.
+ (obstack_finish) [! (defined __GNUC__ && defined __STDC__ &&
+ __STDC__)]: Store temporary in pointer member of union, not
+ integer member.
+ * obstack.c: Include <stddef.h>, for offsetof.
+ (struct fooalign): Remove; it doesn't need a name.
+ (union fooround): Change double to long double, and add void *.
+ (DEFAULT_ALIGNMENT): Use offsetof to compute.
+ (DEFAULT_ALIGNMENT, DEFAULT_ROUNDING): Now an enum constant,
+ not a macro. Hence the values are always int; so remove all
+ casts-to-int in uses.
+
2004-05-16 Paul Eggert <eggert@cs.ucla.edu>
Derek Price <derek@ximbiot.com>
getline cleanup. This changes the getndelim2 API: both order of
arguments, and meaning of delim2 (now uses EOF, not 0, to indicate
no delimiter).
-
+
* getline.c: Don't include stddef.h or stdio.h, since our
interface does that.
(getline): Always use getdelim, so that we don't have two
# include <wchar.h>
#endif
+#include <stddef.h>
+
#ifndef ELIDE_CODE
/* Determine default alignment. */
-struct fooalign {char x; double d;};
-# define DEFAULT_ALIGNMENT \
- ((PTR_INT_TYPE) ((char *) &((struct fooalign *) 0)->d - (char *) 0))
+union fooround
+{
+ long int i;
+ long double d;
+ void *p;
+};
/* If malloc were really smart, it would round addresses to DEFAULT_ALIGNMENT.
But in fact it might be less smart and round addresses to as much as
DEFAULT_ROUNDING. So we prepare for it to do that. */
-union fooround {long x; double d;};
-# define DEFAULT_ROUNDING (sizeof (union fooround))
+enum
+ {
+ DEFAULT_ALIGNMENT = offsetof (struct { char c; union fooround u; }, u),
+ DEFAULT_ROUNDING = sizeof (union fooround)
+ };
/* When we copy a long block of data, this is the unit to do it with.
On some machines, copying successive ints does not work;
register struct _obstack_chunk *chunk; /* points to new chunk */
if (alignment == 0)
- alignment = (int) DEFAULT_ALIGNMENT;
+ alignment = DEFAULT_ALIGNMENT;
if (size == 0)
/* Default size is what GNU malloc can fit in a 4096-byte block. */
{
register struct _obstack_chunk *chunk; /* points to new chunk */
if (alignment == 0)
- alignment = (int) DEFAULT_ALIGNMENT;
+ alignment = DEFAULT_ALIGNMENT;
if (size == 0)
/* Default size is what GNU malloc can fit in a 4096-byte block. */
{
/* Compute an aligned object_base in the new chunk */
object_base =
- __INT_TO_PTR ((__PTR_TO_INT (new_chunk->contents) + h->alignment_mask)
- & ~ (h->alignment_mask));
+ __PTR_ALIGN ((char *) new_chunk, new_chunk->contents, h->alignment_mask);
/* Move the existing object to the new chunk.
Word at a time is fast and is safe if the object
extern "C" {
#endif
\f
-/* We use subtraction of (char *) 0 instead of casting to int
- because on word-addressable machines a simple cast to int
- may ignore the byte-within-word field of the pointer. */
-
-#ifndef __PTR_TO_INT
-# define __PTR_TO_INT(P) ((P) - (char *) 0)
-#endif
-
-#ifndef __INT_TO_PTR
-# define __INT_TO_PTR(P) ((P) + (char *) 0)
-#endif
-
-/* We need the type of the resulting object. If __PTRDIFF_TYPE__ is
+/* We need the type of a pointer subtraction. If __PTRDIFF_TYPE__ is
defined, as with GNU C, use that; that way we don't pollute the
namespace with <stddef.h>'s symbols. Otherwise, include <stddef.h>
and use ptrdiff_t. */
# define PTR_INT_TYPE ptrdiff_t
#endif
+/* If B is the base of an object addressed by P, return the result of
+ aligning P to the next multiple of A + 1. B and P must be of type
+ char *. A + 1 must be a power of 2. */
+
+#define __BPTR_ALIGN(B, P, A) ((B) + (((P) - (B) + (A)) & ~(A)))
+
+/* Similiar to _BPTR_ALIGN (B, P, A), except optimize the common case
+ where pointers can be converted to integers, aligned as integers,
+ and converted back again. If PTR_INT_TYPE is narrower than a
+ pointer (e.g., the AS/400), play it safe and compute the alignment
+ relative to B. Otherwise, use the faster strategy of computing the
+ alignment relative to 0. */
+
+#define __PTR_ALIGN(B, P, A) \
+ __BPTR_ALIGN (sizeof (PTR_INT_TYPE) < sizeof (void *) ? (B) : (char *) 0, \
+ P, A)
+
#include <string.h>
struct _obstack_chunk /* Lives at front of each chunk. */
char *object_base; /* address of object we are building */
char *next_free; /* where to add next char to current object */
char *chunk_limit; /* address of char after current chunk */
- PTR_INT_TYPE temp; /* Temporary for some macros. */
+ union
+ {
+ PTR_INT_TYPE tempint;
+ void *tempptr;
+ } temp; /* Temporary for some macros. */
int alignment_mask; /* Mask of alignment for each object. */
/* These prototypes vary based on `use_extra_arg', and we use
casts to the prototypeless function type in all assignments,
if (__o1->next_free == __value) \
__o1->maybe_empty_object = 1; \
__o1->next_free \
- = __INT_TO_PTR ((__PTR_TO_INT (__o1->next_free)+__o1->alignment_mask)\
- & ~ (__o1->alignment_mask)); \
+ = __PTR_ALIGN (__o1->object_base, __o1->next_free, \
+ __o1->alignment_mask); \
if (__o1->next_free - (char *)__o1->chunk \
> __o1->chunk_limit - (char *)__o1->chunk) \
__o1->next_free = __o1->chunk_limit; \
but some compilers won't accept it. */
# define obstack_make_room(h,length) \
-( (h)->temp = (length), \
- (((h)->next_free + (h)->temp > (h)->chunk_limit) \
- ? (_obstack_newchunk ((h), (h)->temp), 0) : 0))
+( (h)->temp.tempint = (length), \
+ (((h)->next_free + (h)->temp.tempint > (h)->chunk_limit) \
+ ? (_obstack_newchunk ((h), (h)->temp.tempint), 0) : 0))
# define obstack_grow(h,where,length) \
-( (h)->temp = (length), \
- (((h)->next_free + (h)->temp > (h)->chunk_limit) \
- ? (_obstack_newchunk ((h), (h)->temp), 0) : 0), \
- memcpy ((h)->next_free, where, (h)->temp), \
- (h)->next_free += (h)->temp)
+( (h)->temp.tempint = (length), \
+ (((h)->next_free + (h)->temp.tempint > (h)->chunk_limit) \
+ ? (_obstack_newchunk ((h), (h)->temp.tempint), 0) : 0), \
+ memcpy ((h)->next_free, where, (h)->temp.tempint), \
+ (h)->next_free += (h)->temp.tempint)
# define obstack_grow0(h,where,length) \
-( (h)->temp = (length), \
- (((h)->next_free + (h)->temp + 1 > (h)->chunk_limit) \
- ? (_obstack_newchunk ((h), (h)->temp + 1), 0) : 0), \
- memcpy ((h)->next_free, where, (h)->temp), \
- (h)->next_free += (h)->temp, \
+( (h)->temp.tempint = (length), \
+ (((h)->next_free + (h)->temp.tempint + 1 > (h)->chunk_limit) \
+ ? (_obstack_newchunk ((h), (h)->temp.tempint + 1), 0) : 0), \
+ memcpy ((h)->next_free, where, (h)->temp.tempint), \
+ (h)->next_free += (h)->temp.tempint, \
*((h)->next_free)++ = 0)
# define obstack_1grow(h,datum) \
(((int *) ((h)->next_free += sizeof (int)))[-1] = (aptr))
# define obstack_blank(h,length) \
-( (h)->temp = (length), \
- (((h)->chunk_limit - (h)->next_free < (h)->temp) \
- ? (_obstack_newchunk ((h), (h)->temp), 0) : 0), \
- obstack_blank_fast (h, (h)->temp))
+( (h)->temp.tempint = (length), \
+ (((h)->chunk_limit - (h)->next_free < (h)->temp.tempint) \
+ ? (_obstack_newchunk ((h), (h)->temp.tempint), 0) : 0), \
+ obstack_blank_fast (h, (h)->temp.tempint))
# define obstack_alloc(h,length) \
(obstack_blank ((h), (length)), obstack_finish ((h)))
( ((h)->next_free == (h)->object_base \
? (((h)->maybe_empty_object = 1), 0) \
: 0), \
- (h)->temp = __PTR_TO_INT ((h)->object_base), \
+ (h)->temp.tempptr = (h)->object_base, \
(h)->next_free \
- = __INT_TO_PTR ((__PTR_TO_INT ((h)->next_free)+(h)->alignment_mask) \
- & ~ ((h)->alignment_mask)), \
+ = __PTR_ALIGN ((h)->object_base, (h)->next_free, \
+ (h)->alignment_mask), \
(((h)->next_free - (char *) (h)->chunk \
> (h)->chunk_limit - (char *) (h)->chunk) \
? ((h)->next_free = (h)->chunk_limit) : 0), \
(h)->object_base = (h)->next_free, \
- (void *) __INT_TO_PTR ((h)->temp))
+ (h)->temp.tempptr)
# define obstack_free(h,obj) \
-( (h)->temp = (char *) (obj) - (char *) (h)->chunk, \
- (((h)->temp > 0 && (h)->temp < (h)->chunk_limit - (char *) (h)->chunk)\
+( (h)->temp.tempint = (char *) (obj) - (char *) (h)->chunk, \
+ ((((h)->temp.tempint > 0 \
+ && (h)->temp.tempint < (h)->chunk_limit - (char *) (h)->chunk)) \
? (int) ((h)->next_free = (h)->object_base \
- = (h)->temp + (char *) (h)->chunk) \
- : (((obstack_free) ((h), (h)->temp + (char *) (h)->chunk), 0), 0)))
+ = (h)->temp.tempint + (char *) (h)->chunk) \
+ : (((obstack_free) ((h), (h)->temp.tempint + (char *) (h)->chunk), 0), 0)))
#endif /* not __GNUC__ or not __STDC__ */
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