old-cross-binutils/gas/obsolete/gdb-blocks.c
1991-04-04 18:19:56 +00:00

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/* gdb_block.c - Deal with GDB blocks
Copyright (C) 1987 Free Software Foundation, Inc.
This file is part of GAS, the GNU Assembler.
GAS 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 1, or (at your option)
any later version.
GAS 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 GAS; see the file COPYING. If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
/*
* Implements .gdbblk, .gdbbeg, .gdbend concepts.
* No other modules need to know the details of these concepts.
*
* During assembly, note the addresses of block beginnings and ends.
* Each block has a begin-address, an end-address, a number, and
* a place in the GDB symbol file to place the 2 addresses.
* Block numbers are 0, 1, ... with no gaps.
*
* During assembly, we don't actually know the addresses, so they are
* expressed as {frag-address + offset-in-frag}.
*
* gdb_block_begin ()
* Call once before using this package.
*
* gdb_block_beg (number, frag, offset)
* Note a block beginning.
*
* gdb_block_end (number, frag, offset)
* Note a block end.
*
* gdb_block_position (block_number, pos)
* Remember, after assembly, to copy a structure containing
* the beginning and ending addresses of block number
* block_number into the gdb file, starting at position pos.
*
* gdb_block_emit (block_number, where_in_gdb_symbol_file)
* Emit a block begin/end locations to a place in the GDB symbol
* file.
*
* uses:
* xmalloc()
* gdb_alter()
*/
#include "as.h"
/*
* malloc() calls are considered expensive. So ...
*
* We remember blocks by making a tree, and each block number has a leaf.
* The tree is 3 levels, and we don't allocate interior nodes until they
* are needed. Both leaves and interior nodes are allocated in lumps,
* which should save on malloc() calls. Due to the way we break up a
* block number to navigate through the tree, we insist that lumps of
* memory contain a power of 2 items each. Powers of 2 may differ
* for different levels of tree.
*/
/*
* A block number:
*
* +---------------+---------------+---------------+
* | | | |
* | Z2-part bits | Z1-part bits | Z0-part bits |
* | | | |
* +---------------+---------------+---------------+
*
* High order Low order
*
* "Z" is short for "siZe".
*/
#define LOG_2_Z0 (8) /* How many bits are in Z0 part? */
#define LOG_2_Z1 (8) /* How many bits are in Z1 part? */
#define LOG_2_Z2 (8) /* How many bits are in Z2 part? */
#define BLOCK_NUMBER_LIMIT (1 << (LOG_2_Z0 + LOG_2_Z1 + LOG_2_Z2))
/* What is the first block number that is */
/* "too big"? */
struct gdb_block
{
fragS * begin_frag;
fragS * end_frag;
long int begin_where_in_frag;
long int end_where_in_frag;
long int position; /* In GDB symbols file. */
};
typedef struct gdb_block node_0_T [1 << LOG_2_Z0];
typedef node_0_T * node_1_T [1 << LOG_2_Z1];
typedef node_1_T * node_2_T [1 << LOG_2_Z2];
static long int highest_block_number_seen;
static node_2_T * root; /* 3 level tree of block locations. */
static node_2_T * new_2 ();
char * xmalloc();
void gdb_alter();
void
gdb_block_begin ()
{
root = new_2 ();
highest_block_number_seen = -1;
}
static node_0_T *
new_0 ()
{
register node_0_T * place;
place = (node_0_T *) xmalloc ((long)sizeof(node_0_T));
bzero ((char *)place, sizeof(node_0_T));
return (place);
}
static node_1_T *
new_1 ()
{
register node_1_T * place;
place = (node_1_T *) xmalloc ((long)sizeof(node_1_T));
bzero ((char *)place, sizeof(node_1_T));
return (place);
}
static node_2_T *
new_2 ()
{
register node_2_T * place;
place = (node_2_T *) xmalloc ((long)sizeof(node_2_T));
bzero ((char *)place, sizeof(node_2_T));
return (place);
}
static struct gdb_block *
find (block_number)
register long int block_number;
{
register node_1_T ** pp_1;
register node_0_T ** pp_0;
register struct gdb_block * b;
register int index0;
register int index1;
register int index2;
#ifdef SUSPECT
if (block_number >= BLOCK_NUMBER_LIMIT)
{
as_fatal ("gdb_block: Block number = %ld.", block_number);
}
#endif
index2 = block_number >> (LOG_2_Z0 + LOG_2_Z1);
index1 = block_number >> (LOG_2_Z0) & ((1 << LOG_2_Z1) - 1);
index0 = block_number & ((1 << LOG_2_Z0) - 1);
pp_1 = * root + index2;
if (* pp_1 == 0)
{
* pp_1 = new_1 ();
}
pp_0 = ** pp_1 + index1;
if (* pp_0 == 0)
{
* pp_0 = new_0 ();
}
b = ** pp_0 + index0;
return (b);
}
static struct gdb_block *
find_create (block_number)
long int block_number;
{
if (highest_block_number_seen < block_number)
{
highest_block_number_seen = block_number;
}
return (find (block_number));
}
void
gdb_block_beg (block_number, frag, offset)
long int block_number;
fragS * frag;
long int offset;
{
struct gdb_block * pointer;
pointer = find_create (block_number);
#ifdef SUSPECT
if (pointer -> begin_frag != 0)
{
as_warn( "Overwriting begin_frag for block # %ld.", block_number );
}
if (pointer -> begin_where_in_frag != 0)
{
as_warn( "Overwriting begin_where_in_frag for block # %ld.", block_number );
}
#endif
pointer -> begin_frag = frag;
pointer -> begin_where_in_frag = offset;
}
void
gdb_block_end (block_number, frag, offset)
long int block_number;
fragS * frag;
long int offset;
{
struct gdb_block * pointer;
pointer = find_create (block_number);
#ifdef SUSPECT
if (pointer -> end_frag != 0)
{
as_warn( "Overwriting end_frag for block # %ld.", block_number );
}
if (pointer -> end_where_in_frag != 0)
{
as_warn( "Overwriting end_where_in_frag for block # %ld.", block_number );
}
#endif
pointer -> end_frag = frag;
pointer -> end_where_in_frag = offset;
}
void
gdb_block_position (block_number, pos)
long int block_number;
long int pos;
{
struct gdb_block * pointer;
pointer = find_create (block_number);
if (pointer -> position != 0)
{
as_warn( "Overwriting old position %ld. in block #%ld.",
pointer -> position, block_number);
}
pointer -> position = pos;
}
void
gdb_block_emit ()
{
long int block_number;
struct gdb_block * b;
for (block_number = 0;
block_number <= highest_block_number_seen;
block_number ++)
{
b = find (block_number);
if (b -> begin_frag)
{
gdb_alter (b -> position,
(long int)
(b -> begin_frag -> fr_address + b -> begin_where_in_frag));
}
if (b -> end_frag)
{
gdb_alter (b -> position + sizeof( long int ),
(long int)
(b -> end_frag -> fr_address + b -> end_where_in_frag));
}
}
}
/* end: gdb_block.c */