Can you please install the following portability fixes for obstack, merged into libc from gnulib? The only potential problem I can see here is that this changes the type of the "temp" member of struct _obstack. That's a private member so this shouldn't affect user code, and the new size and alignment should be the same on all current glibc platforms. However, if you prefer, I can make this part of the change conditional on (defined _LIBC). 2004-08-11 Paul Eggert <eggert@cs.ucla.edu> Fix portability bugs encountered when porting to Itanium. * malloc/obstack.h (obstack_empty_p, obstack_finish): Do not assume that the "contents" member is suitably aligned. It is not, for some hosts and alignments: e.g., Itanium, long-double. * malloc/obstack.c (_obstack_begin, _obstack_begin_1, _obstack_newchunk): Likewise. * malloc/obstack.c: Include <stddef.h>, for size_t. Include <inttypes.h>, <stdint.h> if needed and available. (DEFAULT_ALIGNMENT): Now an enum constant, not a macro. Use C89 offsetof rather than K&R trick. Use the maximum alignment of uintmax_t, long double, void * rather than the alignment of double. (union fooround): Use uintmax_t, long double, void * members rather than just long and double. Fix portability bugs encountered when porting to the IBM iSeries, where pointers are 256 bits wide and no integers are that wide. * malloc/obstack.h (__PTR_TO_INT, __INT_TO_PTR): Remove. All uses changed to: (__BPTR_ALIGN, __PTR_ALIGN): New macros. (struct _obstack_chunk.temp): Change from int to a union of pointer and int. All uses changed. --- malloc/obstack.h 2004-06-29 11:04:50 -0700 +++ /home/eggert/junk/obstack.h 2004-08-11 15:49:12 -0700 @@ -110,19 +110,7 @@ Summary: extern "C" { #endif -/* 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. */ @@ -134,6 +122,23 @@ extern "C" { # 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. */ @@ -150,7 +155,11 @@ struct obstack /* control current objec 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, @@ -275,7 +284,10 @@ __extension__ \ # define obstack_empty_p(OBSTACK) \ __extension__ \ ({ struct obstack const *__o = (OBSTACK); \ - (__o->chunk->prev == 0 && __o->next_free - __o->chunk->contents == 0); }) + (__o->chunk->prev == 0 \ + && __o->next_free == __PTR_ALIGN ((char *) __o->chunk, \ + __o->chunk->contents, \ + __o->alignment_mask)); }) # define obstack_grow(OBSTACK,where,length) \ __extension__ \ @@ -374,8 +386,8 @@ __extension__ \ 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; \ @@ -399,7 +411,10 @@ __extension__ \ (unsigned) ((h)->chunk_limit - (h)->next_free) # define obstack_empty_p(h) \ - ((h)->chunk->prev == 0 && (h)->next_free - (h)->chunk->contents == 0) + ((h)->chunk->prev == 0 \ + && (h)->next_free == __PTR_ALIGN ((char *) (h)->chunk, \ + (h)->chunk->contents, \ + (h)->alignment_mask)) /* Note that the call to _obstack_newchunk is enclosed in (..., 0) so that we can avoid having void expressions @@ -408,23 +423,23 @@ __extension__ \ 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) \ @@ -449,10 +464,10 @@ __extension__ \ (((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))) @@ -467,22 +482,23 @@ __extension__ \ ( ((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__ */ --- malloc/obstack.c 2004-05-26 11:02:07 -0700 +++ /home/eggert/junk/obstack.c 2004-08-11 15:48:57 -0700 @@ -56,18 +56,33 @@ # include <wchar.h> #endif +#include <stddef.h> + #ifndef ELIDE_CODE +# if HAVE_INTTYPES_H +# include <inttypes.h> +# endif +# if HAVE_STDINT_H || defined _LIBC +# include <stdint.h> +# endif + /* Determine default alignment. */ -struct fooalign {char x; double d;}; -# define DEFAULT_ALIGNMENT \ - ((PTR_INT_TYPE) ((char *) &((struct fooalign *) 0)->d - (char *) 0)) +union fooround +{ + uintmax_t 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; @@ -143,7 +158,7 @@ _obstack_begin (struct obstack *h, 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. */ { @@ -170,7 +185,8 @@ _obstack_begin (struct obstack *h, chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size); if (!chunk) (*obstack_alloc_failed_handler) (); - h->next_free = h->object_base = chunk->contents; + h->next_free = h->object_base = __PTR_ALIGN ((char *) chunk, chunk->contents, + alignment - 1); h->chunk_limit = chunk->limit = (char *) chunk + h->chunk_size; chunk->prev = 0; @@ -189,7 +205,7 @@ _obstack_begin_1 (struct obstack *h, int 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. */ { @@ -217,7 +233,8 @@ _obstack_begin_1 (struct obstack *h, int chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size); if (!chunk) (*obstack_alloc_failed_handler) (); - h->next_free = h->object_base = chunk->contents; + h->next_free = h->object_base = __PTR_ALIGN ((char *) chunk, chunk->contents, + alignment - 1); h->chunk_limit = chunk->limit = (char *) chunk + h->chunk_size; chunk->prev = 0; @@ -259,8 +276,7 @@ _obstack_newchunk (struct obstack *h, in /* 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 @@ -285,7 +301,10 @@ _obstack_newchunk (struct obstack *h, in /* If the object just copied was the only data in OLD_CHUNK, free that chunk and remove it from the chain. But not if that chunk might contain an empty object. */ - if (h->object_base == old_chunk->contents && ! h->maybe_empty_object) + if (! h->maybe_empty_object + && (h->object_base + == __PTR_ALIGN ((char *) old_chunk, old_chunk->contents, + h->alignment_mask))) { new_chunk->prev = old_chunk->prev; CALL_FREEFUN (h, old_chunk);
Please email or attach the patch so the text is not mangled by bugzilla. Also, a fresh patch against the latest glibc trunk would be ideal (though it has changed only trivially).
Created attachment 713 [details] revised patch, against current glibc source OK, I've attached a patch relative to the current glibc sources. New to this patch is: updating the FSF snail mail address, removing obsolete commments referring to /gd/gnu/lib, fixing a portability problem where the code assumed __fxprintf, and removing an unnecessary include of <wchar.h> (no longer needed now that __fxprintf is used).
The trunk files now match gnulib's, modulo license text.