Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame^] | 1 | /* Create new section in output file. |
| 2 | Copyright (C) 2002 Red Hat, Inc. |
| 3 | Written by Ulrich Drepper <drepper@redhat.com>, 2002. |
| 4 | |
| 5 | This program is Open Source software; you can redistribute it and/or |
| 6 | modify it under the terms of the Open Software License version 1.0 as |
| 7 | published by the Open Source Initiative. |
| 8 | |
| 9 | You should have received a copy of the Open Software License along |
| 10 | with this program; if not, you may obtain a copy of the Open Software |
| 11 | License version 1.0 from http://www.opensource.org/licenses/osl.php or |
| 12 | by writing the Open Source Initiative c/o Lawrence Rosen, Esq., |
| 13 | 3001 King Ranch Road, Ukiah, CA 95482. */ |
| 14 | |
| 15 | #ifdef HAVE_CONFIG_H |
| 16 | # include <config.h> |
| 17 | #endif |
| 18 | |
| 19 | #include <assert.h> |
| 20 | #include <error.h> |
| 21 | #include <libintl.h> |
| 22 | #include <stdlib.h> |
| 23 | #include <string.h> |
| 24 | |
| 25 | #include <libasmP.h> |
| 26 | #include <libelf.h> |
| 27 | #include <system.h> |
| 28 | |
| 29 | |
| 30 | /* Memory for the default pattern. The type uses a flexible array |
| 31 | which does work well with a static initializer. So we play some |
| 32 | dirty tricks here. */ |
| 33 | static const struct |
| 34 | { |
| 35 | struct FillPattern pattern; |
| 36 | char zero; |
| 37 | } xdefault_pattern = |
| 38 | { |
| 39 | .pattern = |
| 40 | { |
| 41 | .len = 1 |
| 42 | }, |
| 43 | .zero = '\0' |
| 44 | }; |
| 45 | const struct FillPattern *__libasm_default_pattern = &xdefault_pattern.pattern; |
| 46 | |
| 47 | |
| 48 | static AsmScn_t * |
| 49 | text_newscn (AsmScn_t *result, GElf_Word type, GElf_Xword flags) |
| 50 | { |
| 51 | /* Buffer where we construct the flag string. */ |
| 52 | char flagstr[sizeof (GElf_Xword) * 8 + 5]; |
| 53 | char *wp = flagstr; |
| 54 | const char *typestr = ""; |
| 55 | |
| 56 | /* Only write out the flag string if this is the first time the |
| 57 | section is selected. Some assemblers cannot cope with the |
| 58 | .section pseudo-op otherwise. */ |
| 59 | wp = stpcpy (wp, ", \""); |
| 60 | |
| 61 | if (flags & SHF_WRITE) |
| 62 | *wp++ = 'w'; |
| 63 | if (flags & SHF_ALLOC) |
| 64 | *wp++ = 'a'; |
| 65 | if (flags & SHF_EXECINSTR) |
| 66 | *wp++ = 'x'; |
| 67 | if (flags & SHF_MERGE) |
| 68 | *wp++ = 'M'; |
| 69 | if (flags & SHF_STRINGS) |
| 70 | *wp++ = 'S'; |
| 71 | if (flags & SHF_LINK_ORDER) |
| 72 | *wp++ = 'L'; |
| 73 | |
| 74 | *wp++ = '"'; |
| 75 | |
| 76 | if (type == SHT_PROGBITS) |
| 77 | typestr = ",@progbits"; |
| 78 | else if (type == SHT_NOBITS) |
| 79 | typestr = ",@nobits"; |
| 80 | |
| 81 | /* Terminate the string. */ |
| 82 | *wp = '\0'; |
| 83 | |
| 84 | printf ("\t.section \"%s\"%s%s\n", result->name, flagstr, typestr); |
| 85 | |
| 86 | return result; |
| 87 | } |
| 88 | |
| 89 | |
| 90 | static AsmScn_t * |
| 91 | binary_newscn (AsmScn_t *result, GElf_Word type, GElf_Xword flags, |
| 92 | size_t scnname_len) |
| 93 | { |
| 94 | GElf_Shdr shdr_mem; |
| 95 | GElf_Shdr *shdr; |
| 96 | Elf_Scn *scn; |
| 97 | |
| 98 | /* The initial subsection has the number zero. */ |
| 99 | result->subsection_id = 0; |
| 100 | |
| 101 | /* We start at offset zero. */ |
| 102 | result->offset = 0; |
| 103 | /* And generic alignment. */ |
| 104 | result->max_align = 1; |
| 105 | |
| 106 | /* No output yet. */ |
| 107 | result->content = NULL; |
| 108 | |
| 109 | /* Put the default fill pattern in place. */ |
| 110 | result->pattern = (struct FillPattern *) __libasm_default_pattern; |
| 111 | |
| 112 | /* There are no subsections so far. */ |
| 113 | result->subnext = NULL; |
| 114 | |
| 115 | /* Add the name to the section header string table. */ |
| 116 | result->data.main.strent = ebl_strtabadd (result->ctx->section_strtab, |
| 117 | result->name, scnname_len); |
| 118 | assert (result->data.main.strent != NULL); |
| 119 | |
| 120 | /* Create the new ELF section. */ |
| 121 | result->data.main.scn = scn = elf_newscn (result->ctx->out.elf); |
| 122 | if (scn == NULL) |
| 123 | { |
| 124 | free (result); |
| 125 | __libasm_seterrno (ASM_E_LIBELF); |
| 126 | return NULL; |
| 127 | } |
| 128 | |
| 129 | /* Not part of a section group (yet). */ |
| 130 | result->data.main.next_in_group = NULL; |
| 131 | |
| 132 | /* Remember the flags. */ |
| 133 | shdr = gelf_getshdr (scn, &shdr_mem); |
| 134 | |
| 135 | shdr->sh_flags = flags; |
| 136 | result->type = shdr->sh_type = type; |
| 137 | |
| 138 | (void) gelf_update_shdr (scn, shdr); |
| 139 | |
| 140 | return result; |
| 141 | } |
| 142 | |
| 143 | |
| 144 | AsmScn_t * |
| 145 | asm_newscn (ctx, scnname, type, flags) |
| 146 | AsmCtx_t *ctx; |
| 147 | const char *scnname; |
| 148 | GElf_Word type; |
| 149 | GElf_Xword flags; |
| 150 | { |
| 151 | size_t scnname_len = strlen (scnname) + 1; |
| 152 | unsigned long int hval; |
| 153 | AsmScn_t *result; |
| 154 | |
| 155 | /* If no context is given there might be an earlier error. */ |
| 156 | if (ctx == NULL) |
| 157 | return NULL; |
| 158 | |
| 159 | /* Check whether only flags are set which areselectable by the user. */ |
| 160 | if (unlikely ((flags & ~(SHF_WRITE | SHF_ALLOC | SHF_EXECINSTR | SHF_MERGE |
| 161 | | SHF_STRINGS | SHF_LINK_ORDER)) != 0) |
| 162 | /* We allow only two section types: data and data without file |
| 163 | representation. */ |
| 164 | || (type != SHT_PROGBITS && unlikely (type != SHT_NOBITS))) |
| 165 | { |
| 166 | __libasm_seterrno (ASM_E_INVALID); |
| 167 | return NULL; |
| 168 | } |
| 169 | |
| 170 | hval = elf_hash (scnname); |
| 171 | |
| 172 | rwlock_wrlock (ctx->lock); |
| 173 | |
| 174 | /* This is a new section. */ |
| 175 | result = (AsmScn_t *) malloc (sizeof (AsmScn_t) + scnname_len); |
| 176 | if (result != NULL) |
| 177 | { |
| 178 | /* Add the name. */ |
| 179 | memcpy (result->name, scnname, scnname_len); |
| 180 | |
| 181 | /* Add the reference to the context. */ |
| 182 | result->ctx = ctx; |
| 183 | |
| 184 | /* Perform operations according to output mode. */ |
| 185 | result = (unlikely (ctx->textp) |
| 186 | ? text_newscn (result, type, flags) |
| 187 | : binary_newscn (result, type, flags, scnname_len)); |
| 188 | |
| 189 | /* If everything went well finally add the new section to the hash |
| 190 | table. */ |
| 191 | if (result != NULL) |
| 192 | { |
| 193 | result->allnext = ctx->section_list; |
| 194 | ctx->section_list = result; |
| 195 | } |
| 196 | } |
| 197 | |
| 198 | rwlock_unlock (ctx->lock); |
| 199 | |
| 200 | return result; |
| 201 | } |
| 202 | INTDEF(asm_newscn) |