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 41 typedef struct bytecode_org { 42 unsigned long start; /* target starting offset within section */ 43 unsigned long fill; /* fill value */ 44 } bytecode_org; 45 46 static void bc_org_destroy(void *contents); 47 static void bc_org_print(const void *contents, FILE *f, int indent_level); 48 static void bc_org_finalize(yasm_bytecode *bc, yasm_bytecode *prev_bc); 49 static int bc_org_calc_len(yasm_bytecode *bc, yasm_bc_add_span_func add_span, 50 void *add_span_data); 51 static 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); 54 static 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 59 static 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 71 static void 72 bc_org_destroy(void *contents) 73 { 74 yasm_xfree(contents); 75 } 76 77 static void 78 bc_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 85 static void 86 bc_org_finalize(yasm_bytecode *bc, yasm_bytecode *prev_bc) 87 { 88 } 89 90 static int 91 bc_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 } 103 104 static int 105 bc_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 } 121 122 static int 123 bc_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 } 142 143 yasm_bytecode * 144 yasm_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
