1/*
2 * ORG bytecode
3 *
4 *  Copyright (C) 2005-2007  Peter Johnson
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND OTHER CONTRIBUTORS ``AS IS''
16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR OTHER CONTRIBUTORS BE
19 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
20 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
21 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
22 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
23 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
24 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25 * POSSIBILITY OF SUCH DAMAGE.
26 */
27#include "util.h"
28
29#include "libyasm-stdint.h"
30#include "coretype.h"
31#include "file.h"
32
33#include "errwarn.h"
34#include "intnum.h"
35#include "expr.h"
36#include "value.h"
37
38#include "bytecode.h"
39
40
41typedef struct bytecode_org {
42    unsigned long start;        /* target starting offset within section */
43    unsigned long fill;         /* fill value */
44} bytecode_org;
45
46static void bc_org_destroy(void *contents);
47static void bc_org_print(const void *contents, FILE *f, int indent_level);
48static void bc_org_finalize(yasm_bytecode *bc, yasm_bytecode *prev_bc);
49static int bc_org_calc_len(yasm_bytecode *bc, yasm_bc_add_span_func add_span,
50                           void *add_span_data);
51static int bc_org_expand(yasm_bytecode *bc, int span, long old_val,
52                         long new_val, /*@out@*/ long *neg_thres,
53                         /*@out@*/ long *pos_thres);
54static int bc_org_tobytes(yasm_bytecode *bc, unsigned char **bufp,
55                          unsigned char *bufstart, void *d,
56                          yasm_output_value_func output_value,
57                          /*@null@*/ yasm_output_reloc_func output_reloc);
58
59static const yasm_bytecode_callback bc_org_callback = {
60    bc_org_destroy,
61    bc_org_print,
62    bc_org_finalize,
63    NULL,
64    bc_org_calc_len,
65    bc_org_expand,
66    bc_org_tobytes,
67    YASM_BC_SPECIAL_OFFSET
68};
69
70
71static void
72bc_org_destroy(void *contents)
73{
74    yasm_xfree(contents);
75}
76
77static void
78bc_org_print(const void *contents, FILE *f, int indent_level)
79{
80    const bytecode_org *org = (const bytecode_org *)contents;
81    fprintf(f, "%*s_Org_\n", indent_level, "");
82    fprintf(f, "%*sStart=%lu\n", indent_level, "", org->start);
83}
84
85static void
86bc_org_finalize(yasm_bytecode *bc, yasm_bytecode *prev_bc)
87{
88}
89
90static int
91bc_org_calc_len(yasm_bytecode *bc, yasm_bc_add_span_func add_span,
92                void *add_span_data)
93{
94    bytecode_org *org = (bytecode_org *)bc->contents;
95    long neg_thres = 0;
96    long pos_thres = org->start;
97
98    if (bc_org_expand(bc, 0, 0, (long)bc->offset, &neg_thres, &pos_thres) < 0)
99        return -1;
100
101    return 0;
102}
103
104static int
105bc_org_expand(yasm_bytecode *bc, int span, long old_val, long new_val,
106              /*@out@*/ long *neg_thres, /*@out@*/ long *pos_thres)
107{
108    bytecode_org *org = (bytecode_org *)bc->contents;
109
110    /* Check for overrun */
111    if ((unsigned long)new_val > org->start) {
112        yasm_error_set(YASM_ERROR_GENERAL,
113                       N_("ORG overlap with already existing data"));
114        return -1;
115    }
116
117    /* Generate space to start offset */
118    bc->len = org->start - new_val;
119    return 1;
120}
121
122static int
123bc_org_tobytes(yasm_bytecode *bc, unsigned char **bufp,
124               unsigned char *bufstart, void *d,
125               yasm_output_value_func output_value,
126               /*@unused@*/ yasm_output_reloc_func output_reloc)
127{
128    bytecode_org *org = (bytecode_org *)bc->contents;
129    unsigned long len, i;
130
131    /* Sanity check for overrun */
132    if (bc->offset > org->start) {
133        yasm_error_set(YASM_ERROR_GENERAL,
134                       N_("ORG overlap with already existing data"));
135        return 1;
136    }
137    len = org->start - bc->offset;
138    for (i=0; i<len; i++)
139        YASM_WRITE_8(*bufp, org->fill);     /* XXX: handle more than 8 bit? */
140    return 0;
141}
142
143yasm_bytecode *
144yasm_bc_create_org(unsigned long start, unsigned long fill, unsigned long line)
145{
146    bytecode_org *org = yasm_xmalloc(sizeof(bytecode_org));
147
148    org->start = start;
149    org->fill = fill;
150
151    return yasm_bc_create_common(&bc_org_callback, org, line);
152}
153