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Re: [PATCH] 64-bit obstack support


From: Alan Modra
Subject: Re: [PATCH] 64-bit obstack support
Date: Thu, 30 Oct 2014 12:23:08 +1030
User-agent: Mutt/1.5.23 (2014-03-12)

On Wed, Oct 29, 2014 at 06:34:02PM +0000, Joseph S. Myers wrote:
> On Wed, 29 Oct 2014, Alan Modra wrote:
> 
> > And >2G on 32-bit.
> > 
> 
>       [BZ #14483]
> 
> in the ChangeLog entry.

Thanks, added.  Since the stdalign.h change won't do for glibc, I've
split the glibc patch into two.  The first being

    Import new obstack support from gnulib
    
        * malloc/obstack.h: Import from gnulib.
        * malloc/obstack.c: Likewise.

The second

    64-bit obstack support
    
    And >2G on 32-bit.
    
        [BZ #14483]
        * include/gnu-versions.h (_GNU_OBSTACK_INTERFACE_VERSION): Bump.
        * include/obstack.h: Include shlib-compat.h and gnu-versions.h.
        (_OBSTACK_ELIDE_CODE, _OBSTACK_NO_ERROR_HANDLER, _OBSTACK_COMPAT,
        _OBSTACK_ALIAS): Define.
        (_obstack_allocated_p, _obstack_newchunk, _obstack_free,
        _obstack_begin, _obstack_begin_1, _obstack_memory_used): Define.
        (_obstack_newchunk): Only use libc_hidden_proto on the version
        we will use inside glibc.
        * malloc/obstack.c: Revert gnulib commit e8f86ce9, ie. don't
        use stdalign.h and alignof.
        * malloc/obstackv1.c: New file.
        * malloc/obstackv2.c: New file.
        * malloc/Makefile (routines): Remove obstack.  Add obstackv1 and
        obstackv2.
        (CFLAGS-obstack.c): Don't define.
        (CFLAGS-obstackv1.c, CFLAGS-obstackv2.c): Define.
        (malloc/Versions): Add GLIBC_2.21 _obstack functions.
        * config.h.in (SIZEOF_INT, SIZEOF_SIZE_T): Add.
        * configure.in: AC_CHECK_SIZEOF int and size_t.
        * configure: Regenerate.
        * manual/memory.texi: Update obstack documentation.

Added manual patch follows.  It's missing @safety markup for the
previously undocumented obstack_begin, obstack_specify_allocation, and
obstack_specify_allocation_with_arg macros.  I'm hoping someone else
can do that as I'd just be guessing.  (Are they even appropriate for
macros?)

diff --git a/manual/memory.texi b/manual/memory.texi
index 0729e70..5ab16b7 100644
--- a/manual/memory.texi
+++ b/manual/memory.texi
@@ -1922,8 +1922,7 @@ the padding needed to start each object on a suitable 
boundary.
                                 use obstacks.
 * Allocation in an Obstack::    Allocating objects in an obstack.
 * Freeing Obstack Objects::     Freeing objects in an obstack.
-* Obstack Functions::          The obstack functions are both
-                                functions and macros.
+* Obstack Functions::          The obstack functions are really macros.
 * Growing Objects::             Making an object bigger by stages.
 * Extra Fast Growing::         Extra-high-efficiency (though more
                                 complicated) growing objects.
@@ -1948,7 +1947,7 @@ An obstack is represented by a data structure of type 
@code{struct
 obstack}.  This structure has a small fixed size; it records the status
 of the obstack and how to find the space in which objects are allocated.
 It does not contain any of the objects themselves.  You should not try
-to access the contents of the structure directly; use only the functions
+to access the contents of the structure directly; use only the macros
 described in this chapter.
 @end deftp
 
@@ -1958,7 +1957,7 @@ of object.  Dynamic allocation of obstacks allows your 
program to have a
 variable number of different stacks.  (You can even allocate an
 obstack structure in another obstack, but this is rarely useful.)
 
-All the functions that work with obstacks require you to specify which
+All the macros that work with obstacks require you to specify which
 obstack to use.  You do this with a pointer of type @code{struct obstack
 *}.  In the following, we often say ``an obstack'' when strictly
 speaking the object at hand is such a pointer.
@@ -1978,7 +1977,7 @@ These matters are described in the following section.
 @node Preparing for Obstacks
 @subsubsection Preparing for Using Obstacks
 
-Each source file in which you plan to use the obstack functions
+Each source file in which you plan to use obstacks
 must include the header file @file{obstack.h}, like this:
 
 @smallexample
@@ -2011,7 +2010,9 @@ larger blocks of memory.  @xref{Obstack Chunks}, for full 
details.
 
 At run time, before the program can use a @code{struct obstack} object
 as an obstack, it must initialize the obstack by calling
address@hidden
address@hidden or one of its variants, @code{obstack_begin},
address@hidden, or
address@hidden
 
 @comment obstack.h
 @comment GNU
@@ -2031,10 +2032,10 @@ as an obstack, it must initialize the obstack by calling
 @c  fxprintf dup @asucorrupt @aculock @acucorrupt
 @c  exit @acucorrupt?
 Initialize obstack @var{obstack-ptr} for allocation of objects.  This
-function calls the obstack's @code{obstack_chunk_alloc} function.  If
+macro calls the obstack's @code{obstack_chunk_alloc} function.  If
 allocation of memory fails, the function pointed to by
 @code{obstack_alloc_failed_handler} is called.  The @code{obstack_init}
-function always returns 1 (Compatibility notice: Former versions of
+macro always returns 1 (Compatibility notice: Former versions of
 obstack returned 0 if allocation failed).
 @end deftypefun
 
@@ -2059,6 +2060,29 @@ obstack_init (myobstack_ptr);
 
 @comment obstack.h
 @comment GNU
address@hidden int obstack_begin (struct obstack address@hidden, size_t 
chunk_size)
+Like @code{obstack_init}, but specify an initial chunk of
address@hidden bytes.
address@hidden deftypefun
+
address@hidden obstack.h
address@hidden GNU
address@hidden int obstack_specify_allocation (struct obstack address@hidden, 
size_t chunk_size, size_t alignment, void *(*chunkfun) (size_t), void 
(*freefun) (void *))
+Like @code{obstack_init}, specifying intial chunk size, chunk
+alignment, and memory allocation functions.  A @var{chunk_size} or
address@hidden of zero results in the default size or alignment
+respectively being used.
address@hidden deftypefun
+
address@hidden obstack.h
address@hidden GNU
address@hidden int obstack_specify_allocation_with_arg (struct obstack 
address@hidden, size_t chunk_size, size_t alignment, void *(*chunkfun) (void *, 
size_t), void (*freefun) (void *, void *), void *arg)
+Like @code{obstack_specify_allocation}, but specifying memory
+allocation functions that take an extra first argument, @var{arg}.
address@hidden deftypefun
+
address@hidden obstack.h
address@hidden GNU
 @defvar obstack_alloc_failed_handler
 The value of this variable is a pointer to a function that
 @code{obstack} uses when @code{obstack_chunk_alloc} fails to allocate
@@ -2084,7 +2108,7 @@ The most direct way to allocate an object in an obstack 
is with
 
 @comment obstack.h
 @comment GNU
address@hidden {void *} obstack_alloc (struct obstack address@hidden, int 
@var{size})
address@hidden {void *} obstack_alloc (struct obstack address@hidden, size_t 
@var{size})
 @address@hidden@address@hidden:address@hidden@address@hidden @acsmem{}}}
 @c obstack_alloc @mtsrace:obstack-ptr @acucorrupt @acsmem
 @c  obstack_blank dup @mtsrace:obstack-ptr @acucorrupt @acsmem
@@ -2092,10 +2116,10 @@ The most direct way to allocate an object in an obstack 
is with
 This allocates an uninitialized block of @var{size} bytes in an obstack
 and returns its address.  Here @var{obstack-ptr} specifies which obstack
 to allocate the block in; it is the address of the @code{struct obstack}
-object which represents the obstack.  Each obstack function or macro
+object which represents the obstack.  Each obstack macro
 requires you to specify an @var{obstack-ptr} as the first argument.
 
-This function calls the obstack's @code{obstack_chunk_alloc} function if
+This macro calls the obstack's @code{obstack_chunk_alloc} function if
 it needs to allocate a new chunk of memory; it calls
 @code{obstack_alloc_failed_handler} if allocation of memory by
 @code{obstack_chunk_alloc} failed.
@@ -2117,12 +2141,11 @@ copystring (char *string)
 @}
 @end smallexample
 
-To allocate a block with specified contents, use the function
address@hidden, declared like this:
+To allocate a block with specified contents, use the macro @code{obstack_copy}.
 
 @comment obstack.h
 @comment GNU
address@hidden {void *} obstack_copy (struct obstack address@hidden, void 
address@hidden, int @var{size})
address@hidden {void *} obstack_copy (struct obstack address@hidden, void 
address@hidden, size_t @var{size})
 @address@hidden@address@hidden:address@hidden@address@hidden @acsmem{}}}
 @c obstack_copy @mtsrace:obstack-ptr @acucorrupt @acsmem
 @c  obstack_grow dup @mtsrace:obstack-ptr @acucorrupt @acsmem
@@ -2135,7 +2158,7 @@ bytes of data starting at @var{address}.  It calls
 
 @comment obstack.h
 @comment GNU
address@hidden {void *} obstack_copy0 (struct obstack address@hidden, void 
address@hidden, int @var{size})
address@hidden {void *} obstack_copy0 (struct obstack address@hidden, void 
address@hidden, size_t @var{size})
 @address@hidden@address@hidden:address@hidden@address@hidden @acsmem{}}}
 @c obstack_copy0 @mtsrace:obstack-ptr @acucorrupt @acsmem
 @c  obstack_grow0 dup @mtsrace:obstack-ptr @acucorrupt @acsmem
@@ -2144,13 +2167,13 @@ Like @code{obstack_copy}, but appends an extra byte 
containing a null
 character.  This extra byte is not counted in the argument @var{size}.
 @end deftypefun
 
-The @code{obstack_copy0} function is convenient for copying a sequence
+The @code{obstack_copy0} macro is convenient for copying a sequence
 of characters into an obstack as a null-terminated string.  Here is an
 example of its use:
 
 @smallexample
 char *
-obstack_savestring (char *addr, int size)
+obstack_savestring (char *addr, size_t size)
 @{
   return obstack_copy0 (&myobstack, addr, size);
 @}
@@ -2164,7 +2187,7 @@ Contrast this with the previous example of 
@code{savestring} using
 @subsubsection Freeing Objects in an Obstack
 @cindex freeing (obstacks)
 
-To free an object allocated in an obstack, use the function
+To free an object allocated in an obstack, use the macro
 @code{obstack_free}.  Since the obstack is a stack of objects, freeing
 one object automatically frees all other objects allocated more recently
 in the same obstack.
@@ -2200,13 +2223,9 @@ obstacks, or non-obstack allocation, can reuse the space 
of the chunk.
 @subsubsection Obstack Functions and Macros
 @cindex macros
 
-The interfaces for using obstacks may be defined either as functions or
-as macros, depending on the compiler.  The obstack facility works with
-all C compilers, including both @w{ISO C} and traditional C, but there are
-precautions you must take if you plan to use compilers other than GNU C.
-
-If you are using an old-fashioned @w{non-ISO C} compiler, all the obstack
-``functions'' are actually defined only as macros.  You can call these
+The interfaces for using obstacks are shown here as functions to
+specify the return types and give a hint as to expected argument
+types, but they are really defined as macros.  You can call these
 macros like functions, but you cannot use them in any other way (for
 example, you cannot take their address).
 
@@ -2224,34 +2243,15 @@ If you use @code{*obstack_list_ptr++} as the obstack 
pointer argument,
 you will get very strange results since the incrementation may occur
 several times.
 
-In @w{ISO C}, each function has both a macro definition and a function
-definition.  The function definition is used if you take the address of the
-function without calling it.  An ordinary call uses the macro definition by
-default, but you can request the function definition instead by writing the
-function name in parentheses, as shown here:
-
address@hidden
-char *x;
-void *(*funcp) ();
-/* @r{Use the macro}.  */
-x = (char *) obstack_alloc (obptr, size);
-/* @r{Call the function}.  */
-x = (char *) (obstack_alloc) (obptr, size);
-/* @r{Take the address of the function}.  */
-funcp = obstack_alloc;
address@hidden smallexample
-
address@hidden
-This is the same situation that exists in @w{ISO C} for the standard library
-functions.  @xref{Macro Definitions}.
-
address@hidden:} When you do use the macros, you must observe the
-precaution of avoiding side effects in the first operand, even in @w{ISO C}.
-
 If you use the GNU C compiler, this precaution is not necessary, because
 various language extensions in GNU C permit defining the macros so as to
 compute each argument only once.
 
address@hidden does declare a number of functions,
address@hidden, @code{_obstack_begin_1},
address@hidden, @code{_obstack_free}, and
address@hidden  You should not call these directly.
+
 @node Growing Objects
 @subsubsection Growing Objects
 @cindex growing objects (in obstacks)
@@ -2261,13 +2261,13 @@ Because memory in obstack chunks is used sequentially, 
it is possible to
 build up an object step by step, adding one or more bytes at a time to the
 end of the object.  With this technique, you do not need to know how much
 data you will put in the object until you come to the end of it.  We call
-this the technique of @dfn{growing objects}.  The special functions
+this the technique of @dfn{growing objects}.  The special macros
 for adding data to the growing object are described in this section.
 
 You don't need to do anything special when you start to grow an object.
-Using one of the functions to add data to the object automatically
+Using one of the macros to add data to the object automatically
 starts it.  However, it is necessary to say explicitly when the object is
-finished.  This is done with the function @code{obstack_finish}.
+finished.  This is done with @code{obstack_finish}.
 
 The actual address of the object thus built up is not known until the
 object is finished.  Until then, it always remains possible that you will
@@ -2279,7 +2279,7 @@ already added to the growing object will become part of 
the other object.
 
 @comment obstack.h
 @comment GNU
address@hidden void obstack_blank (struct obstack address@hidden, int 
@var{size})
address@hidden void obstack_blank (struct obstack address@hidden, size_t 
@var{size})
 @address@hidden@address@hidden:address@hidden@address@hidden @acsmem{}}}
 @c obstack_blank @mtsrace:obstack-ptr @acucorrupt @acsmem
 @c  _obstack_newchunk @mtsrace:obstack-ptr @acucorrupt @acsmem
@@ -2287,13 +2287,13 @@ already added to the growing object will become part of 
the other object.
 @c   *obstack_alloc_failed_handler dup user-supplied
 @c   *freefun
 @c  obstack_blank_fast dup @mtsrace:obstack-ptr
-The most basic function for adding to a growing object is
+The most basic macro for adding to a growing object is
 @code{obstack_blank}, which adds space without initializing it.
 @end deftypefun
 
 @comment obstack.h
 @comment GNU
address@hidden void obstack_grow (struct obstack address@hidden, void 
address@hidden, int @var{size})
address@hidden void obstack_grow (struct obstack address@hidden, void 
address@hidden, size_t @var{size})
 @address@hidden@address@hidden:address@hidden@address@hidden @acsmem{}}}
 @c obstack_grow @mtsrace:obstack-ptr @acucorrupt @acsmem
 @c  _obstack_newchunk dup @mtsrace:obstack-ptr @acucorrupt @acsmem
@@ -2306,7 +2306,7 @@ bytes of data to the growing object, copying the contents 
from
 
 @comment obstack.h
 @comment GNU
address@hidden void obstack_grow0 (struct obstack address@hidden, void 
address@hidden, int @var{size})
address@hidden void obstack_grow0 (struct obstack address@hidden, void 
address@hidden, size_t @var{size})
 @address@hidden@address@hidden:address@hidden@address@hidden @acsmem{}}}
 @c obstack_grow0 @mtsrace:obstack-ptr @acucorrupt @acsmem
 @c   (no sequence point between storing NUL and incrementing next_free)
@@ -2325,7 +2325,7 @@ character.
 @c obstack_1grow @mtsrace:obstack-ptr @acucorrupt @acsmem
 @c  _obstack_newchunk dup @mtsrace:obstack-ptr @acucorrupt @acsmem
 @c  obstack_1grow_fast dup @mtsrace:obstack-ptr @acucorrupt @acsmem
-To add one character at a time, use the function @code{obstack_1grow}.
+To add one character at a time, use @code{obstack_1grow}.
 It adds a single byte containing @var{c} to the growing object.
 @end deftypefun
 
@@ -2336,7 +2336,7 @@ It adds a single byte containing @var{c} to the growing 
object.
 @c obstack_ptr_grow @mtsrace:obstack-ptr @acucorrupt @acsmem
 @c  _obstack_newchunk dup @mtsrace:obstack-ptr @acucorrupt @acsmem
 @c  obstack_ptr_grow_fast dup @mtsrace:obstack-ptr
-Adding the value of a pointer one can use the function
+Adding the value of a pointer one can use
 @code{obstack_ptr_grow}.  It adds @code{sizeof (void *)} bytes
 containing the value of @var{data}.
 @end deftypefun
@@ -2348,8 +2348,8 @@ containing the value of @var{data}.
 @c obstack_int_grow @mtsrace:obstack-ptr @acucorrupt @acsmem
 @c  _obstack_newchunk dup @mtsrace:obstack-ptr @acucorrupt @acsmem
 @c  obstack_int_grow_fast dup @mtsrace:obstack-ptr
-A single value of type @code{int} can be added by using the
address@hidden function.  It adds @code{sizeof (int)} bytes to
+A single value of type @code{int} can be added by using
address@hidden  It adds @code{sizeof (int)} bytes to
 the growing object and initializes them with the value of @var{data}.
 @end deftypefun
 
@@ -2358,28 +2358,24 @@ the growing object and initializes them with the value 
of @var{data}.
 @deftypefun {void *} obstack_finish (struct obstack address@hidden)
 @address@hidden@address@hidden:address@hidden@address@hidden
 @c obstack_finish @mtsrace:obstack-ptr @acucorrupt
-When you are finished growing the object, use the function
+When you are finished growing the object, use
 @code{obstack_finish} to close it off and return its final address.
 
 Once you have finished the object, the obstack is available for ordinary
 allocation or for growing another object.
-
-This function can return a null pointer under the same conditions as
address@hidden (@pxref{Allocation in an Obstack}).
 @end deftypefun
 
 When you build an object by growing it, you will probably need to know
 afterward how long it became.  You need not keep track of this as you grow
-the object, because you can find out the length from the obstack just
-before finishing the object with the function @code{obstack_object_size},
-declared as follows:
+the object, because you can find out the length from the obstack
+with @code{obstack_object_size}, before finishing the object.
 
 @comment obstack.h
 @comment GNU
address@hidden int obstack_object_size (struct obstack address@hidden)
address@hidden size_t obstack_object_size (struct obstack address@hidden)
 @address@hidden@address@hidden:address@hidden@acsafe{}}
-This function returns the current size of the growing object, in bytes.
-Remember to call this function @emph{before} finishing the object.
+This macro returns the current size of the growing object, in bytes.
+Remember to call @code{obstack_object_size} @emph{before} finishing the object.
 After it is finished, @code{obstack_object_size} will return zero.
 @end deftypefun
 
@@ -2393,41 +2389,36 @@ obstack_free (obstack_ptr, obstack_finish 
(obstack_ptr));
 @noindent
 This has no effect if no object was growing.
 
address@hidden shrinking objects
-You can use @code{obstack_blank} with a negative size argument to make
-the current object smaller.  Just don't try to shrink it beyond zero
-length---there's no telling what will happen if you do that.
-
 @node Extra Fast Growing
 @subsubsection Extra Fast Growing Objects
 @cindex efficiency and obstacks
 
-The usual functions for growing objects incur overhead for checking
+The usual macros for growing objects incur overhead for checking
 whether there is room for the new growth in the current chunk.  If you
 are frequently constructing objects in small steps of growth, this
 overhead can be significant.
 
 You can reduce the overhead by using special ``fast growth''
-functions that grow the object without checking.  In order to have a
+macros that grow the object without checking.  In order to have a
 robust program, you must do the checking yourself.  If you do this checking
 in the simplest way each time you are about to add data to the object, you
 have not saved anything, because that is what the ordinary growth
-functions do.  But if you can arrange to check less often, or check
+macros do.  But if you can arrange to check less often, or check
 more efficiently, then you make the program faster.
 
-The function @code{obstack_room} returns the amount of room available
-in the current chunk.  It is declared as follows:
address@hidden returns the amount of room available
+in the current chunk.
 
 @comment obstack.h
 @comment GNU
address@hidden int obstack_room (struct obstack address@hidden)
address@hidden size_t obstack_room (struct obstack address@hidden)
 @address@hidden@address@hidden:address@hidden@acsafe{}}
 This returns the number of bytes that can be added safely to the current
 growing object (or to an object about to be started) in obstack
address@hidden using the fast growth functions.
address@hidden using the fast growth macros.
 @end deftypefun
 
-While you know there is room, you can use these fast growth functions
+While you know there is room, you can use these fast growth macros
 for adding data to a growing object:
 
 @comment obstack.h
@@ -2436,7 +2427,7 @@ for adding data to a growing object:
 @address@hidden@address@hidden:address@hidden@address@hidden @acsmem{}}}
 @c obstack_1grow_fast @mtsrace:obstack-ptr @acucorrupt @acsmem
 @c   (no sequence point between copying c and incrementing next_free)
-The function @code{obstack_1grow_fast} adds one byte containing the
address@hidden adds one byte containing the
 character @var{c} to the growing object in obstack @var{obstack-ptr}.
 @end deftypefun
 
@@ -2445,7 +2436,7 @@ character @var{c} to the growing object in obstack 
@var{obstack-ptr}.
 @deftypefun void obstack_ptr_grow_fast (struct obstack address@hidden, void 
address@hidden)
 @address@hidden@address@hidden:address@hidden@acsafe{}}
 @c obstack_ptr_grow_fast @mtsrace:obstack-ptr
-The function @code{obstack_ptr_grow_fast} adds @code{sizeof (void *)}
address@hidden adds @code{sizeof (void *)}
 bytes containing the value of @var{data} to the growing object in
 obstack @var{obstack-ptr}.
 @end deftypefun
@@ -2455,41 +2446,41 @@ obstack @var{obstack-ptr}.
 @deftypefun void obstack_int_grow_fast (struct obstack address@hidden, int 
@var{data})
 @address@hidden@address@hidden:address@hidden@acsafe{}}
 @c obstack_int_grow_fast @mtsrace:obstack-ptr
-The function @code{obstack_int_grow_fast} adds @code{sizeof (int)} bytes
address@hidden adds @code{sizeof (int)} bytes
 containing the value of @var{data} to the growing object in obstack
 @var{obstack-ptr}.
 @end deftypefun
 
 @comment obstack.h
 @comment GNU
address@hidden void obstack_blank_fast (struct obstack address@hidden, int 
@var{size})
address@hidden void obstack_blank_fast (struct obstack address@hidden, size_t 
@var{size})
 @address@hidden@address@hidden:address@hidden@acsafe{}}
 @c obstack_blank_fast @mtsrace:obstack-ptr
-The function @code{obstack_blank_fast} adds @var{size} bytes to the
address@hidden adds @var{size} bytes to the
 growing object in obstack @var{obstack-ptr} without initializing them.
 @end deftypefun
 
 When you check for space using @code{obstack_room} and there is not
-enough room for what you want to add, the fast growth functions
+enough room for what you want to add, the fast growth macros
 are not safe.  In this case, simply use the corresponding ordinary
-growth function instead.  Very soon this will copy the object to a
+growth macro instead.  Very soon this will copy the object to a
 new chunk; then there will be lots of room available again.
 
-So, each time you use an ordinary growth function, check afterward for
+So, each time you use an ordinary growth macro, check afterward for
 sufficient space using @code{obstack_room}.  Once the object is copied
 to a new chunk, there will be plenty of space again, so the program will
-start using the fast growth functions again.
+start using the fast growth macros again.
 
 Here is an example:
 
 @smallexample
 @group
 void
-add_string (struct obstack *obstack, const char *ptr, int len)
+add_string (struct obstack *obstack, const char *ptr, size_t len)
 @{
   while (len > 0)
     @{
-      int room = obstack_room (obstack);
+      size_t room = obstack_room (obstack);
       if (room == 0)
         @{
           /* @r{Not enough room.  Add one character slowly,}
@@ -2511,12 +2502,17 @@ add_string (struct obstack *obstack, const char *ptr, 
int len)
 @end group
 @end smallexample
 
address@hidden shrinking objects
+You can use @code{obstack_blank_fast} with a negative size argument to make
+the current object smaller.  Just don't try to shrink it beyond zero
+length---there's no telling what will happen if you do that.
+
 @node Status of an Obstack
 @subsubsection Status of an Obstack
 @cindex obstack status
 @cindex status of obstack
 
-Here are functions that provide information on the current status of
+Here are macros that provide information on the current status of
 allocation in an obstack.  You can use them to learn about an object while
 still growing it.
 
@@ -2524,7 +2520,7 @@ still growing it.
 @comment GNU
 @deftypefun {void *} obstack_base (struct obstack address@hidden)
 @address@hidden@address@hidden@address@hidden
-This function returns the tentative address of the beginning of the
+This macro returns the tentative address of the beginning of the
 currently growing object in @var{obstack-ptr}.  If you finish the object
 immediately, it will have that address.  If you make it larger first, it
 may outgrow the current chunk---then its address will change!
@@ -2538,7 +2534,7 @@ chunk).
 @comment GNU
 @deftypefun {void *} obstack_next_free (struct obstack address@hidden)
 @address@hidden@address@hidden@address@hidden
-This function returns the address of the first free byte in the current
+This macro returns the address of the first free byte in the current
 chunk of obstack @var{obstack-ptr}.  This is the end of the currently
 growing object.  If no object is growing, @code{obstack_next_free}
 returns the same value as @code{obstack_base}.
@@ -2546,14 +2542,14 @@ returns the same value as @code{obstack_base}.
 
 @comment obstack.h
 @comment GNU
address@hidden int obstack_object_size (struct obstack address@hidden)
address@hidden size_t obstack_object_size (struct obstack address@hidden)
 @c dup
 @address@hidden@address@hidden:address@hidden@acsafe{}}
-This function returns the size in bytes of the currently growing object.
+This macro returns the size in bytes of the currently growing object.
 This is equivalent to
 
 @smallexample
-obstack_next_free (@var{obstack-ptr}) - obstack_base (@var{obstack-ptr})
+((size_t) obstack_next_free (@var{obstack-ptr}) - obstack_base 
(@var{obstack-ptr}))
 @end smallexample
 @end deftypefun
 
@@ -2567,12 +2563,11 @@ specified boundary.  By default, this boundary is 
aligned so that
 the object can hold any type of data.
 
 To access an obstack's alignment boundary, use the macro
address@hidden, whose function prototype looks like
-this:
address@hidden
 
 @comment obstack.h
 @comment GNU
address@hidden Macro int obstack_alignment_mask (struct obstack address@hidden)
address@hidden Macro size_t obstack_alignment_mask (struct obstack 
address@hidden)
 @address@hidden@address@hidden@acsafe{}}
 The value is a bit mask; a bit that is 1 indicates that the corresponding
 bit in the address of an object should be 0.  The mask value should be one
@@ -2640,7 +2635,7 @@ not to waste too much memory in the portion of the last 
chunk not yet used.
 
 @comment obstack.h
 @comment GNU
address@hidden Macro int obstack_chunk_size (struct obstack address@hidden)
address@hidden Macro size_t obstack_chunk_size (struct obstack address@hidden)
 @address@hidden@address@hidden@acsafe{}}
 This returns the chunk size of the given obstack.
 @end deftypefn
@@ -2659,25 +2654,37 @@ if (obstack_chunk_size (obstack_ptr) < 
@var{new-chunk-size})
 @end smallexample
 
 @node Summary of Obstacks
address@hidden Summary of Obstack Functions
address@hidden Summary of Obstack Macros
 
-Here is a summary of all the functions associated with obstacks.  Each
+Here is a summary of all the macros associated with obstacks.  Each
 takes the address of an obstack (@code{struct obstack *}) as its first
 argument.
 
 @table @code
address@hidden void obstack_init (struct obstack address@hidden)
address@hidden int obstack_init (struct obstack address@hidden)
 Initialize use of an obstack.  @xref{Creating Obstacks}.
 
address@hidden void *obstack_alloc (struct obstack address@hidden, int 
@var{size})
address@hidden int obstack_begin (struct obstack address@hidden, size_t 
chunk_size)
+Initialize use of an obstack, with an initial chunk of
address@hidden bytes.
+
address@hidden int obstack_specify_allocation (struct obstack address@hidden, 
size_t chunk_size, size_t alignment, void *(*chunkfun) (size_t), void 
(*freefun) (void *))
+Initialize use of an obstack, specifying intial chunk size, chunk
+alignment, and memory allocation functions.
+
address@hidden int obstack_specify_allocation_with_arg (struct obstack 
address@hidden, size_t chunk_size, size_t alignment, void *(*chunkfun) (void *, 
size_t), void (*freefun) (void *, void *), void *arg)
+Like @code{obstack_specify_allocation}, but specifying memory
+allocation functions that take an extra first argument, @var{arg}.
+
address@hidden void *obstack_alloc (struct obstack address@hidden, size_t 
@var{size})
 Allocate an object of @var{size} uninitialized bytes.
 @xref{Allocation in an Obstack}.
 
address@hidden void *obstack_copy (struct obstack address@hidden, void 
address@hidden, int @var{size})
address@hidden void *obstack_copy (struct obstack address@hidden, void 
address@hidden, size_t @var{size})
 Allocate an object of @var{size} bytes, with contents copied from
 @var{address}.  @xref{Allocation in an Obstack}.
 
address@hidden void *obstack_copy0 (struct obstack address@hidden, void 
address@hidden, int @var{size})
address@hidden void *obstack_copy0 (struct obstack address@hidden, void 
address@hidden, size_t @var{size})
 Allocate an object of @var{size}+1 bytes, with @var{size} of them copied
 from @var{address}, followed by a null character at the end.
 @xref{Allocation in an Obstack}.
@@ -2686,15 +2693,15 @@ from @var{address}, followed by a null character at the 
end.
 Free @var{object} (and everything allocated in the specified obstack
 more recently than @var{object}).  @xref{Freeing Obstack Objects}.
 
address@hidden void obstack_blank (struct obstack address@hidden, int 
@var{size})
address@hidden void obstack_blank (struct obstack address@hidden, size_t 
@var{size})
 Add @var{size} uninitialized bytes to a growing object.
 @xref{Growing Objects}.
 
address@hidden void obstack_grow (struct obstack address@hidden, void 
address@hidden, int @var{size})
address@hidden void obstack_grow (struct obstack address@hidden, void 
address@hidden, size_t @var{size})
 Add @var{size} bytes, copied from @var{address}, to a growing object.
 @xref{Growing Objects}.
 
address@hidden void obstack_grow0 (struct obstack address@hidden, void 
address@hidden, int @var{size})
address@hidden void obstack_grow0 (struct obstack address@hidden, void 
address@hidden, size_t @var{size})
 Add @var{size} bytes, copied from @var{address}, to a growing object,
 and then add another byte containing a null character.  @xref{Growing
 Objects}.
@@ -2707,11 +2714,11 @@ Add one byte containing @var{data-char} to a growing 
object.
 Finalize the object that is growing and return its permanent address.
 @xref{Growing Objects}.
 
address@hidden int obstack_object_size (struct obstack address@hidden)
address@hidden size_t obstack_object_size (struct obstack address@hidden)
 Get the current size of the currently growing object.  @xref{Growing
 Objects}.
 
address@hidden void obstack_blank_fast (struct obstack address@hidden, int 
@var{size})
address@hidden void obstack_blank_fast (struct obstack address@hidden, size_t 
@var{size})
 Add @var{size} uninitialized bytes to a growing object without checking
 that there is enough room.  @xref{Extra Fast Growing}.
 
@@ -2719,15 +2726,15 @@ that there is enough room.  @xref{Extra Fast Growing}.
 Add one byte containing @var{data-char} to a growing object without
 checking that there is enough room.  @xref{Extra Fast Growing}.
 
address@hidden int obstack_room (struct obstack address@hidden)
address@hidden size_t obstack_room (struct obstack address@hidden)
 Get the amount of room now available for growing the current object.
 @xref{Extra Fast Growing}.
 
address@hidden int obstack_alignment_mask (struct obstack address@hidden)
address@hidden size_t obstack_alignment_mask (struct obstack address@hidden)
 The mask used for aligning the beginning of an object.  This is an
 lvalue.  @xref{Obstacks Data Alignment}.
 
address@hidden int obstack_chunk_size (struct obstack address@hidden)
address@hidden size_t obstack_chunk_size (struct obstack address@hidden)
 The size for allocating chunks.  This is an lvalue.  @xref{Obstack Chunks}.
 
 @item void *obstack_base (struct obstack address@hidden)

-- 
Alan Modra
Australia Development Lab, IBM



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