mirror of https://github.com/yasm/yasm.git
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
246 lines
7.3 KiB
246 lines
7.3 KiB
/* |
|
* Align bytecode |
|
* |
|
* Copyright (C) 2005-2006 Peter Johnson |
|
* |
|
* Redistribution and use in source and binary forms, with or without |
|
* modification, are permitted provided that the following conditions |
|
* are met: |
|
* 1. Redistributions of source code must retain the above copyright |
|
* notice, this list of conditions and the following disclaimer. |
|
* 2. Redistributions in binary form must reproduce the above copyright |
|
* notice, this list of conditions and the following disclaimer in the |
|
* documentation and/or other materials provided with the distribution. |
|
* |
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND OTHER CONTRIBUTORS ``AS IS'' |
|
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR OTHER CONTRIBUTORS BE |
|
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
|
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
|
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
|
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
|
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
|
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
|
* POSSIBILITY OF SUCH DAMAGE. |
|
*/ |
|
#define YASM_LIB_INTERNAL |
|
#include "util.h" |
|
/*@unused@*/ RCSID("$Id$"); |
|
|
|
#include "libyasm-stdint.h" |
|
#include "coretype.h" |
|
|
|
#include "errwarn.h" |
|
#include "intnum.h" |
|
#include "expr.h" |
|
|
|
#include "bytecode.h" |
|
|
|
#include "bc-int.h" |
|
|
|
|
|
typedef struct bytecode_align { |
|
/*@only@*/ yasm_expr *boundary; /* alignment boundary */ |
|
|
|
/* What to fill intervening locations with, NULL if using code_fill */ |
|
/*@only@*/ /*@null@*/ yasm_expr *fill; |
|
|
|
/* Maximum number of bytes to skip, NULL if no maximum. */ |
|
/*@only@*/ /*@null@*/ yasm_expr *maxskip; |
|
|
|
/* Code fill, NULL if using 0 fill */ |
|
/*@null@*/ const unsigned char **code_fill; |
|
} bytecode_align; |
|
|
|
static void bc_align_destroy(void *contents); |
|
static void bc_align_print(const void *contents, FILE *f, int indent_level); |
|
static void bc_align_finalize(yasm_bytecode *bc, yasm_bytecode *prev_bc); |
|
static int bc_align_calc_len(yasm_bytecode *bc, yasm_bc_add_span_func add_span, |
|
void *add_span_data); |
|
static int bc_align_expand(yasm_bytecode *bc, int span, long old_val, |
|
long new_val, /*@out@*/ long *neg_thres, |
|
/*@out@*/ long *pos_thres); |
|
static int bc_align_tobytes(yasm_bytecode *bc, unsigned char **bufp, void *d, |
|
yasm_output_value_func output_value, |
|
/*@null@*/ yasm_output_reloc_func output_reloc); |
|
|
|
static const yasm_bytecode_callback bc_align_callback = { |
|
bc_align_destroy, |
|
bc_align_print, |
|
bc_align_finalize, |
|
bc_align_calc_len, |
|
bc_align_expand, |
|
bc_align_tobytes, |
|
YASM_BC_SPECIAL_OFFSET |
|
}; |
|
|
|
|
|
static void |
|
bc_align_destroy(void *contents) |
|
{ |
|
bytecode_align *align = (bytecode_align *)contents; |
|
if (align->boundary) |
|
yasm_expr_destroy(align->boundary); |
|
if (align->fill) |
|
yasm_expr_destroy(align->fill); |
|
if (align->maxskip) |
|
yasm_expr_destroy(align->maxskip); |
|
yasm_xfree(contents); |
|
} |
|
|
|
static void |
|
bc_align_print(const void *contents, FILE *f, int indent_level) |
|
{ |
|
const bytecode_align *align = (const bytecode_align *)contents; |
|
fprintf(f, "%*s_Align_\n", indent_level, ""); |
|
fprintf(f, "%*sBoundary=", indent_level, ""); |
|
yasm_expr_print(align->boundary, f); |
|
fprintf(f, "\n%*sFill=", indent_level, ""); |
|
yasm_expr_print(align->fill, f); |
|
fprintf(f, "\n%*sMax Skip=", indent_level, ""); |
|
yasm_expr_print(align->maxskip, f); |
|
fprintf(f, "\n"); |
|
} |
|
|
|
static void |
|
bc_align_finalize(yasm_bytecode *bc, yasm_bytecode *prev_bc) |
|
{ |
|
bytecode_align *align = (bytecode_align *)bc->contents; |
|
if (!yasm_expr_get_intnum(&align->boundary, 0)) |
|
yasm_error_set(YASM_ERROR_NOT_CONSTANT, |
|
N_("align boundary must be a constant")); |
|
if (align->fill && !yasm_expr_get_intnum(&align->fill, 0)) |
|
yasm_error_set(YASM_ERROR_NOT_CONSTANT, |
|
N_("align fill must be a constant")); |
|
if (align->maxskip && !yasm_expr_get_intnum(&align->maxskip, 0)) |
|
yasm_error_set(YASM_ERROR_NOT_CONSTANT, |
|
N_("align maximum skip must be a constant")); |
|
} |
|
|
|
static int |
|
bc_align_calc_len(yasm_bytecode *bc, yasm_bc_add_span_func add_span, |
|
void *add_span_data) |
|
{ |
|
long neg_thres = 0; |
|
long pos_thres = 0; |
|
|
|
if (bc_align_expand(bc, 0, 0, (long)bc->offset, &neg_thres, |
|
&pos_thres) < 0) |
|
return -1; |
|
|
|
return 0; |
|
} |
|
|
|
static int |
|
bc_align_expand(yasm_bytecode *bc, int span, long old_val, long new_val, |
|
/*@out@*/ long *neg_thres, /*@out@*/ long *pos_thres) |
|
{ |
|
bytecode_align *align = (bytecode_align *)bc->contents; |
|
unsigned long end; |
|
unsigned long boundary = |
|
yasm_intnum_get_uint(yasm_expr_get_intnum(&align->boundary, 0)); |
|
|
|
if (boundary == 0) { |
|
bc->len = 0; |
|
*pos_thres = new_val; |
|
return 0; |
|
} |
|
|
|
end = (unsigned long)new_val; |
|
if ((unsigned long)new_val & (boundary-1)) |
|
end = ((unsigned long)new_val & ~(boundary-1)) + boundary; |
|
|
|
*pos_thres = (long)end; |
|
bc->len = end - (unsigned long)new_val; |
|
|
|
if (align->maxskip) { |
|
unsigned long maxskip = |
|
yasm_intnum_get_uint(yasm_expr_get_intnum(&align->maxskip, 0)); |
|
if (bc->len > maxskip) { |
|
*pos_thres = (long)end-maxskip-1; |
|
bc->len = 0; |
|
} |
|
} |
|
return 1; |
|
} |
|
|
|
static int |
|
bc_align_tobytes(yasm_bytecode *bc, unsigned char **bufp, void *d, |
|
yasm_output_value_func output_value, |
|
/*@unused@*/ yasm_output_reloc_func output_reloc) |
|
{ |
|
bytecode_align *align = (bytecode_align *)bc->contents; |
|
unsigned long len; |
|
unsigned long boundary = |
|
yasm_intnum_get_uint(yasm_expr_get_intnum(&align->boundary, 0)); |
|
|
|
if (boundary == 0) |
|
return 0; |
|
else { |
|
unsigned long end = bc->offset; |
|
if (bc->offset & (boundary-1)) |
|
end = (bc->offset & ~(boundary-1)) + boundary; |
|
len = end - bc->offset; |
|
if (len == 0) |
|
return 0; |
|
if (align->maxskip) { |
|
unsigned long maxskip = |
|
yasm_intnum_get_uint(yasm_expr_get_intnum(&align->maxskip, 0)); |
|
if (len > maxskip) |
|
return 0; |
|
} |
|
} |
|
|
|
if (align->fill) { |
|
unsigned long v; |
|
v = yasm_intnum_get_uint(yasm_expr_get_intnum(&align->fill, 0)); |
|
memset(*bufp, (int)v, len); |
|
*bufp += len; |
|
} else if (align->code_fill) { |
|
unsigned long maxlen = 15; |
|
while (!align->code_fill[maxlen] && maxlen>0) |
|
maxlen--; |
|
if (maxlen == 0) { |
|
yasm_error_set(YASM_ERROR_GENERAL, |
|
N_("could not find any code alignment size")); |
|
return 1; |
|
} |
|
|
|
/* Fill with maximum code fill as much as possible */ |
|
while (len > maxlen) { |
|
memcpy(*bufp, align->code_fill[maxlen], maxlen); |
|
*bufp += maxlen; |
|
len -= maxlen; |
|
} |
|
|
|
if (!align->code_fill[len]) { |
|
yasm_error_set(YASM_ERROR_VALUE, |
|
N_("invalid alignment size %d"), len); |
|
return 1; |
|
} |
|
/* Handle rest of code fill */ |
|
memcpy(*bufp, align->code_fill[len], len); |
|
*bufp += len; |
|
} else { |
|
/* Just fill with 0 */ |
|
memset(*bufp, 0, len); |
|
*bufp += len; |
|
} |
|
return 0; |
|
} |
|
|
|
yasm_bytecode * |
|
yasm_bc_create_align(yasm_expr *boundary, yasm_expr *fill, |
|
yasm_expr *maxskip, const unsigned char **code_fill, |
|
unsigned long line) |
|
{ |
|
bytecode_align *align = yasm_xmalloc(sizeof(bytecode_align)); |
|
|
|
align->boundary = boundary; |
|
align->fill = fill; |
|
align->maxskip = maxskip; |
|
align->code_fill = code_fill; |
|
|
|
return yasm_bc_create_common(&bc_align_callback, align, line); |
|
}
|
|
|