1 /* Create descriptor for assembling. 2 Copyright (C) 2002 Red Hat, Inc. 3 This file is part of Red Hat elfutils. 4 Written by Ulrich Drepper <drepper (at) redhat.com>, 2002. 5 6 Red Hat elfutils is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by the 8 Free Software Foundation; version 2 of the License. 9 10 Red Hat elfutils is distributed in the hope that it will be useful, but 11 WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 General Public License for more details. 14 15 You should have received a copy of the GNU General Public License along 16 with Red Hat elfutils; if not, write to the Free Software Foundation, 17 Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. 18 19 Red Hat elfutils is an included package of the Open Invention Network. 20 An included package of the Open Invention Network is a package for which 21 Open Invention Network licensees cross-license their patents. No patent 22 license is granted, either expressly or impliedly, by designation as an 23 included package. Should you wish to participate in the Open Invention 24 Network licensing program, please visit www.openinventionnetwork.com 25 <http://www.openinventionnetwork.com>. */ 26 27 #ifdef HAVE_CONFIG_H 28 # include <config.h> 29 #endif 30 31 #include <assert.h> 32 #include <errno.h> 33 #include <stdio.h> 34 #include <stdio_ext.h> 35 #include <stdlib.h> 36 #include <string.h> 37 #include <unistd.h> 38 39 #include <gelf.h> 40 #include "libasmP.h" 41 #include <system.h> 42 43 44 static AsmCtx_t * 45 prepare_text_output (AsmCtx_t *result) 46 { 47 if (result->fd == -1) 48 result->out.file = stdout; 49 else 50 { 51 result->out.file = fdopen (result->fd, "a"); 52 if (result->out.file == NULL) 53 { 54 close (result->fd); 55 free (result); 56 result = NULL; 57 } 58 59 __fsetlocking (result->out.file, FSETLOCKING_BYCALLER); 60 } 61 62 return result; 63 } 64 65 66 static AsmCtx_t * 67 prepare_binary_output (AsmCtx_t *result, Ebl *ebl) 68 { 69 GElf_Ehdr *ehdr; 70 GElf_Ehdr ehdr_mem; 71 72 /* Create the ELF descriptor for the file. */ 73 result->out.elf = elf_begin (result->fd, ELF_C_WRITE_MMAP, NULL); 74 if (result->out.elf == NULL) 75 { 76 err_libelf: 77 unlink (result->tmp_fname); 78 close (result->fd); 79 free (result); 80 __libasm_seterrno (ASM_E_LIBELF); 81 return NULL; 82 } 83 84 /* Create the ELF header for the output file. */ 85 int class = ebl_get_elfclass (ebl); 86 if (gelf_newehdr (result->out.elf, class) == 0) 87 goto err_libelf; 88 89 ehdr = gelf_getehdr (result->out.elf, &ehdr_mem); 90 /* If this failed we are in trouble. */ 91 assert (ehdr != NULL); 92 93 /* We create an object file. */ 94 ehdr->e_type = ET_REL; 95 /* Set the ELF version. */ 96 ehdr->e_version = EV_CURRENT; 97 98 /* Use the machine, class, and endianess values from the Ebl descriptor. */ 99 ehdr->e_machine = ebl_get_elfmachine (ebl); 100 ehdr->e_ident[EI_CLASS] = class; 101 ehdr->e_ident[EI_DATA] = ebl_get_elfdata (ebl); 102 103 memcpy (&ehdr->e_ident[EI_MAG0], ELFMAG, SELFMAG); 104 105 /* Write the ELF header information back. */ 106 (void) gelf_update_ehdr (result->out.elf, ehdr); 107 108 /* No section so far. */ 109 result->section_list = NULL; 110 111 /* Initialize the hash table. */ 112 asm_symbol_tab_init (&result->symbol_tab, 67); 113 result->nsymbol_tab = 0; 114 /* And the string tables. */ 115 result->section_strtab = ebl_strtabinit (true); 116 result->symbol_strtab = ebl_strtabinit (true); 117 118 /* We have no section groups so far. */ 119 result->groups = NULL; 120 result->ngroups = 0; 121 122 return result; 123 } 124 125 126 AsmCtx_t * 127 asm_begin (fname, ebl, textp) 128 const char *fname; 129 Ebl *ebl; 130 bool textp; 131 { 132 if (fname == NULL && ! textp) 133 return NULL; 134 135 size_t fname_len = fname != NULL ? strlen (fname) : 0; 136 137 /* Create the file descriptor. We do not generate the output file 138 right away. Instead we create a temporary file in the same 139 directory which, if everything goes alright, will replace a 140 possibly existing file with the given name. */ 141 AsmCtx_t *result 142 = (AsmCtx_t *) malloc (sizeof (AsmCtx_t) + 2 * fname_len + 9); 143 if (result == NULL) 144 return NULL; 145 146 /* Initialize the lock. */ 147 rwlock_init (result->lock); 148 149 if (fname != NULL) 150 { 151 /* Create the name of the temporary file. */ 152 result->fname = stpcpy (mempcpy (result->tmp_fname, fname, fname_len), 153 ".XXXXXX") + 1; 154 memcpy (result->fname, fname, fname_len + 1); 155 156 /* Create the temporary file. */ 157 result->fd = mkstemp (result->tmp_fname); 158 if (result->fd == -1) 159 { 160 int save_errno = errno; 161 free (result); 162 __libasm_seterrno (ASM_E_CANNOT_CREATE); 163 errno = save_errno; 164 return NULL; 165 } 166 } 167 else 168 result->fd = -1; 169 170 /* Initialize the counter for temporary symbols. */ 171 result->tempsym_count = 0; 172 173 /* Now we differentiate between textual and binary output. */ 174 result->textp = textp; 175 if (textp) 176 result = prepare_text_output (result); 177 else 178 result = prepare_binary_output (result, ebl); 179 180 return result; 181 } 182
