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+/* obstack.h - object stack macros
+ Copyright (C) 1988-1994,1996-1999,2003,2004,2005,2006
+ Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2, or (at your option)
+ any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along
+ with this program; if not, write to the Free Software Foundation,
+ Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+
+/* Summary:
+
+All the apparent functions defined here are macros. The idea
+is that you would use these pre-tested macros to solve a
+very specific set of problems, and they would run fast.
+Caution: no side-effects in arguments please!! They may be
+evaluated MANY times!!
+
+These macros operate a stack of objects. Each object starts life
+small, and may grow to maturity. (Consider building a word syllable
+by syllable.) An object can move while it is growing. Once it has
+been "finished" it never changes address again. So the "top of the
+stack" is typically an immature growing object, while the rest of the
+stack is of mature, fixed size and fixed address objects.
+
+These routines grab large chunks of memory, using a function you
+supply, called `obstack_chunk_alloc'. On occasion, they free chunks,
+by calling `obstack_chunk_free'. You must define them and declare
+them before using any obstack macros.
+
+Each independent stack is represented by a `struct obstack'.
+Each of the obstack macros expects a pointer to such a structure
+as the first argument.
+
+One motivation for this package is the problem of growing char strings
+in symbol tables. Unless you are "fascist pig with a read-only mind"
+--Gosper's immortal quote from HAKMEM item 154, out of context--you
+would not like to put any arbitrary upper limit on the length of your
+symbols.
+
+In practice this often means you will build many short symbols and a
+few long symbols. At the time you are reading a symbol you don't know
+how long it is. One traditional method is to read a symbol into a
+buffer, realloc()ating the buffer every time you try to read a symbol
+that is longer than the buffer. This is beaut, but you still will
+want to copy the symbol from the buffer to a more permanent
+symbol-table entry say about half the time.
+
+With obstacks, you can work differently. Use one obstack for all symbol
+names. As you read a symbol, grow the name in the obstack gradually.
+When the name is complete, finalize it. Then, if the symbol exists already,
+free the newly read name.
+
+The way we do this is to take a large chunk, allocating memory from
+low addresses. When you want to build a symbol in the chunk you just
+add chars above the current "high water mark" in the chunk. When you
+have finished adding chars, because you got to the end of the symbol,
+you know how long the chars are, and you can create a new object.
+Mostly the chars will not burst over the highest address of the chunk,
+because you would typically expect a chunk to be (say) 100 times as
+long as an average object.
+
+In case that isn't clear, when we have enough chars to make up
+the object, THEY ARE ALREADY CONTIGUOUS IN THE CHUNK (guaranteed)
+so we just point to it where it lies. No moving of chars is
+needed and this is the second win: potentially long strings need
+never be explicitly shuffled. Once an object is formed, it does not
+change its address during its lifetime.
+
+When the chars burst over a chunk boundary, we allocate a larger
+chunk, and then copy the partly formed object from the end of the old
+chunk to the beginning of the new larger chunk. We then carry on
+accreting characters to the end of the object as we normally would.
+
+A special macro is provided to add a single char at a time to a
+growing object. This allows the use of register variables, which
+break the ordinary 'growth' macro.
+
+Summary:
+ We allocate large chunks.
+ We carve out one object at a time from the current chunk.
+ Once carved, an object never moves.
+ We are free to append data of any size to the currently
+ growing object.
+ Exactly one object is growing in an obstack at any one time.
+ You can run one obstack per control block.
+ You may have as many control blocks as you dare.
+ Because of the way we do it, you can `unwind' an obstack
+ back to a previous state. (You may remove objects much
+ as you would with a stack.)
+*/
+
+
+/* Don't do the contents of this file more than once. */
+
+#ifndef _OBSTACK_H
+#define _OBSTACK_H 1
+
+# include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#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)))
+
+/* Similar 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 ptrdiff_t 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 (ptrdiff_t) < sizeof (void *) ? (B) : (char *) 0, \
+ P, A)
+
+#include <string.h>
+
+struct _obstack_chunk /* Lives at front of each chunk. */
+{
+ char *limit; /* 1 past end of this chunk */
+ struct _obstack_chunk *prev; /* address of prior chunk or NULL */
+ char contents[4]; /* objects begin here */
+};
+
+struct obstack /* control current object in current chunk */
+{
+ size_t chunk_size; /* preferred size to allocate chunks in */
+ struct _obstack_chunk *chunk; /* address of current struct obstack_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 */
+ union
+ {
+ ptrdiff_t tempint;
+ void *tempptr;
+ } temp; /* Temporary for some macros. */
+ size_t 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,
+ but having prototypes here quiets -Wstrict-prototypes. */
+ union {
+ void *(*arg1) (size_t);
+ void *(*arg2) (void *, size_t);
+ } chunkfun;
+ union {
+ void (*arg1) (void *);
+ void (*arg2) (void *, void *);
+ } freefun;
+ void *extra_arg; /* first arg for chunk alloc/dealloc funcs */
+ unsigned use_extra_arg:1; /* chunk alloc/dealloc funcs take extra arg */
+ unsigned maybe_empty_object:1;/* There is a possibility that the current
+ chunk contains a zero-length object. This
+ prevents freeing the chunk if we allocate
+ a bigger chunk to replace it. */
+ unsigned alloc_failed:1; /* No longer used, as we now call the failed
+ handler on error, but retained for binary
+ compatibility. */
+};
+
+/* Declare the external functions we use; they are in obstack.c. */
+
+extern void _obstack_newchunk (struct obstack *, size_t);
+extern int _obstack_begin (struct obstack *, size_t, size_t,
+ void *(*) (size_t), void (*) (void *));
+extern int _obstack_begin_1 (struct obstack *, size_t, size_t,
+ void *(*) (void *, size_t),
+ void (*) (void *, void *), void *);
+extern size_t _obstack_memory_used (struct obstack *);
+
+/* The default name of the function for freeing a chunk is 'obstack_free',
+ but gnulib users can override this by defining '__obstack_free'. */
+#ifndef __obstack_free
+# define __obstack_free obstack_free
+#endif
+extern void __obstack_free (struct obstack *obstack, void *block);
+
+
+/* Error handler called when `obstack_chunk_alloc' failed to allocate
+ more memory. This can be set to a user defined function which
+ should either abort gracefully or use longjmp - but shouldn't
+ return. The default action is to print a message and abort. */
+extern void (*obstack_alloc_failed_handler) (void);
+
+/* Exit value used when `print_and_abort' is used. */
+extern int obstack_exit_failure;
+
+/* Pointer to beginning of object being allocated or to be allocated next.
+ Note that this might not be the final address of the object
+ because a new chunk might be needed to hold the final size. */
+
+#define obstack_base(h) ((void *) (h)->object_base)
+
+/* Size for allocating ordinary chunks. */
+
+#define obstack_chunk_size(h) ((h)->chunk_size)
+
+/* Pointer to next byte not yet allocated in current chunk. */
+
+#define obstack_next_free(h) ((h)->next_free)
+
+/* Mask specifying low bits that should be clear in address of an object. */
+
+#define obstack_alignment_mask(h) ((h)->alignment_mask)
+
+/* To prevent prototype warnings provide complete argument list. */
+#define obstack_init(h) \
+ _obstack_begin ((h), 0, 0, \
+ (void *(*) (size_t)) obstack_chunk_alloc, \
+ (void (*) (void *)) obstack_chunk_free)
+
+#define obstack_begin(h, size) \
+ _obstack_begin ((h), (size), 0, \
+ (void *(*) (size_t)) obstack_chunk_alloc, \
+ (void (*) (void *)) obstack_chunk_free)
+
+#define obstack_specify_allocation(h, size, alignment, chunkfun, freefun) \
+ _obstack_begin ((h), (size), (alignment), \
+ (void *(*) (size_t)) (chunkfun), \
+ (void (*) (void *)) (freefun))
+
+#define obstack_specify_allocation_with_arg(h, size, alignment, chunkfun, freefun, arg) \
+ _obstack_begin_1 ((h), (size), (alignment), \
+ (void *(*) (void *, size_t)) (chunkfun), \
+ (void (*) (void *, void *)) (freefun), (arg))
+
+#define obstack_chunkfun(h, newchunkfun) \
+ ((h) -> chunkfun.arg2 = (struct _obstack_chunk *(*)(void *, size_t)) (newchunkfun))
+
+#define obstack_freefun(h, newfreefun) \
+ ((h) -> freefun.arg2 = (void (*)(void *, struct _obstack_chunk *)) (newfreefun))
+
+#define obstack_1grow_fast(h,achar) (*((h)->next_free)++ = (achar))
+
+#define obstack_blank_fast(h,n) ((h)->next_free += (n))
+
+#define obstack_memory_used(h) _obstack_memory_used (h)
+
+#if defined __GNUC__ && defined __STDC__ && __STDC__
+/* NextStep 2.0 cc is really gcc 1.93 but it defines __GNUC__ = 2 and
+ does not implement __extension__. But that compiler doesn't define
+ __GNUC_MINOR__. */
+# if __GNUC__ < 2 || (__NeXT__ && !__GNUC_MINOR__)
+# define __extension__
+# endif
+
+/* For GNU C, if not -traditional,
+ we can define these macros to compute all args only once
+ without using a global variable.
+ Also, we can avoid using the `temp' slot, to make faster code. */
+
+# define obstack_object_size(OBSTACK) \
+ __extension__ \
+ ({ struct obstack const *__o = (OBSTACK); \
+ (size_t) (__o->next_free - __o->object_base); })
+
+# define obstack_room(OBSTACK) \
+ __extension__ \
+ ({ struct obstack const *__o = (OBSTACK); \
+ (size_t) (__o->chunk_limit - __o->next_free); })
+
+# define obstack_make_room(OBSTACK,length) \
+__extension__ \
+({ struct obstack *__o = (OBSTACK); \
+ size_t __len = (length); \
+ if ((size_t) (__o->chunk_limit - __o->next_free) < __len) \
+ _obstack_newchunk (__o, __len); \
+ (void) 0; })
+
+# define obstack_empty_p(OBSTACK) \
+ __extension__ \
+ ({ struct obstack const *__o = (OBSTACK); \
+ (__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__ \
+({ struct obstack *__o = (OBSTACK); \
+ size_t __len = (length); \
+ if (__o->next_free + __len > __o->chunk_limit) \
+ _obstack_newchunk (__o, __len); \
+ memcpy (__o->next_free, where, __len); \
+ __o->next_free += __len; \
+ (void) 0; })
+
+# define obstack_grow0(OBSTACK,where,length) \
+__extension__ \
+({ struct obstack *__o = (OBSTACK); \
+ size_t __len = (length); \
+ if (__o->next_free + __len + 1 > __o->chunk_limit) \
+ _obstack_newchunk (__o, __len + 1); \
+ memcpy (__o->next_free, where, __len); \
+ __o->next_free += __len; \
+ *(__o->next_free)++ = 0; \
+ (void) 0; })
+
+# define obstack_1grow(OBSTACK,datum) \
+__extension__ \
+({ struct obstack *__o = (OBSTACK); \
+ if (__o->next_free + 1 > __o->chunk_limit) \
+ _obstack_newchunk (__o, 1); \
+ obstack_1grow_fast (__o, datum); \
+ (void) 0; })
+
+/* These assume that the obstack alignment is good enough for pointers
+ or ints, and that the data added so far to the current object
+ shares that much alignment. */
+
+# define obstack_ptr_grow(OBSTACK,datum) \
+__extension__ \
+({ struct obstack *__o = (OBSTACK); \
+ if (__o->next_free + sizeof (void *) > __o->chunk_limit) \
+ _obstack_newchunk (__o, sizeof (void *)); \
+ obstack_ptr_grow_fast (__o, datum); }) \
+
+# define obstack_int_grow(OBSTACK,datum) \
+__extension__ \
+({ struct obstack *__o = (OBSTACK); \
+ if (__o->next_free + sizeof (int) > __o->chunk_limit) \
+ _obstack_newchunk (__o, sizeof (int)); \
+ obstack_int_grow_fast (__o, datum); })
+
+# define obstack_ptr_grow_fast(OBSTACK,aptr) \
+__extension__ \
+({ struct obstack *__o1 = (OBSTACK); \
+ *(const void **) __o1->next_free = (aptr); \
+ __o1->next_free += sizeof (const void *); \
+ (void) 0; })
+
+# define obstack_int_grow_fast(OBSTACK,aint) \
+__extension__ \
+({ struct obstack *__o1 = (OBSTACK); \
+ *(int *) __o1->next_free = (aint); \
+ __o1->next_free += sizeof (int); \
+ (void) 0; })
+
+# define obstack_blank(OBSTACK,length) \
+__extension__ \
+({ struct obstack *__o = (OBSTACK); \
+ size_t __len = (length); \
+ if ((size_t) (__o->chunk_limit - __o->next_free) < __len) \
+ _obstack_newchunk (__o, __len); \
+ obstack_blank_fast (__o, __len); \
+ (void) 0; })
+
+# define obstack_alloc(OBSTACK,length) \
+__extension__ \
+({ struct obstack *__h = (OBSTACK); \
+ obstack_blank (__h, (length)); \
+ obstack_finish (__h); })
+
+# define obstack_copy(OBSTACK,where,length) \
+__extension__ \
+({ struct obstack *__h = (OBSTACK); \
+ obstack_grow (__h, (where), (length)); \
+ obstack_finish (__h); })
+
+# define obstack_copy0(OBSTACK,where,length) \
+__extension__ \
+({ struct obstack *__h = (OBSTACK); \
+ obstack_grow0 (__h, (where), (length)); \
+ obstack_finish (__h); })
+
+/* The local variable is named __o1 to avoid a name conflict
+ when obstack_blank is called. */
+# define obstack_finish(OBSTACK) \
+__extension__ \
+({ struct obstack *__o1 = (OBSTACK); \
+ void *__value = (void *) __o1->object_base; \
+ if (__o1->next_free == __value) \
+ __o1->maybe_empty_object = 1; \
+ __o1->next_free \
+ = __PTR_ALIGN (__o1->object_base, __o1->next_free, \
+ __o1->alignment_mask); \
+ if ((size_t) (__o1->next_free - (char *)__o1->chunk) \
+ > (size_t) (__o1->chunk_limit - (char *)__o1->chunk)) \
+ __o1->next_free = __o1->chunk_limit; \
+ __o1->object_base = __o1->next_free; \
+ __value; })
+
+# define obstack_free(OBSTACK, OBJ) \
+__extension__ \
+({ struct obstack *__o = (OBSTACK); \
+ void *__obj = (OBJ); \
+ if (__obj > (void *)__o->chunk && __obj < (void *)__o->chunk_limit) \
+ __o->next_free = __o->object_base = (char *)__obj; \
+ else (__obstack_free) (__o, __obj); })
+
+#else /* not __GNUC__ or not __STDC__ */
+
+# define obstack_object_size(h) \
+ (size_t) ((h)->next_free - (h)->object_base)
+
+# define obstack_room(h) \
+ (size_t) ((h)->chunk_limit - (h)->next_free)
+
+# define obstack_empty_p(h) \
+ ((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
+ in the arms of the conditional expression.
+ Casting the third operand to void was tried before,
+ but some compilers won't accept it. */
+
+# define obstack_make_room(h,length) \
+( (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.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.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) \
+( (((h)->next_free + 1 > (h)->chunk_limit) \
+ ? (_obstack_newchunk ((h), 1), 0) : 0), \
+ obstack_1grow_fast (h, datum))
+
+# define obstack_ptr_grow(h,datum) \
+( (((h)->next_free + sizeof (char *) > (h)->chunk_limit) \
+ ? (_obstack_newchunk ((h), sizeof (char *)), 0) : 0), \
+ obstack_ptr_grow_fast (h, datum))
+
+# define obstack_int_grow(h,datum) \
+( (((h)->next_free + sizeof (int) > (h)->chunk_limit) \
+ ? (_obstack_newchunk ((h), sizeof (int)), 0) : 0), \
+ obstack_int_grow_fast (h, datum))
+
+# define obstack_ptr_grow_fast(h,aptr) \
+ (((const void **) ((h)->next_free += sizeof (void *)))[-1] = (aptr))
+
+# define obstack_int_grow_fast(h,aint) \
+ (((int *) ((h)->next_free += sizeof (int)))[-1] = (aint))
+
+# define obstack_blank(h,length) \
+( (h)->temp.tempint = (length), \
+ (((size_t) ((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)))
+
+# define obstack_copy(h,where,length) \
+ (obstack_grow ((h), (where), (length)), obstack_finish ((h)))
+
+# define obstack_copy0(h,where,length) \
+ (obstack_grow0 ((h), (where), (length)), obstack_finish ((h)))
+
+# define obstack_finish(h) \
+( ((h)->next_free == (h)->object_base \
+ ? (((h)->maybe_empty_object = 1), 0) \
+ : 0), \
+ (h)->temp.tempptr = (h)->object_base, \
+ (h)->next_free \
+ = __PTR_ALIGN ((h)->object_base, (h)->next_free, \
+ (h)->alignment_mask), \
+ (((size_t) ((h)->next_free - (char *) (h)->chunk) \
+ > (size_t) ((h)->chunk_limit - (char *) (h)->chunk)) \
+ ? ((h)->next_free = (h)->chunk_limit) : 0), \
+ (h)->object_base = (h)->next_free, \
+ (h)->temp.tempptr)
+
+# define obstack_free(h,obj) \
+( (h)->temp.tempint = (char *) (obj) - (char *) (h)->chunk, \
+ ((((h)->temp.tempint > 0 \
+ && (h)->temp.tempint < (size_t) ((h)->chunk_limit - (char *) (h)->chunk))) \
+ ? (int) ((h)->next_free = (h)->object_base \
+ = (h)->temp.tempint + (char *) (h)->chunk) \
+ : (((__obstack_free) ((h), (h)->temp.tempint + (char *) (h)->chunk), 0), 0)))
+
+#endif /* not __GNUC__ or not __STDC__ */
+
+#ifdef __cplusplus
+} /* C++ */
+#endif
+
+#endif /* obstack.h */
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