/* Mach-O support for BFD.
Copyright 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
- 2009, 2010, 2011
+ 2009, 2010, 2011, 2012
Free Software Foundation, Inc.
This file is part of BFD, the Binary File Descriptor library.
#include "mach-o/reloc.h"
#include "mach-o/external.h"
#include <ctype.h>
+#include <stdlib.h>
+#include <string.h>
#define bfd_mach_o_object_p bfd_mach_o_gen_object_p
#define bfd_mach_o_core_p bfd_mach_o_gen_core_p
bfd_size_type str_index;
bfd_mach_o_asymbol *s = (bfd_mach_o_asymbol *)symbols[i];
- /* Compute name index. */
- /* An index of 0 always means the empty string. */
+ /* For a bare indirect symbol, the system tools expect that the symbol
+ value will be the string table offset for its referenced counterpart.
+
+ Normally, indirect syms will not be written this way, but rather as
+ part of the dysymtab command.
+
+ In either case, correct operation depends on the symbol table being
+ sorted such that the indirect symbols are at the end (since the
+ string table index is filled in below). */
+
+ if (IS_MACHO_INDIRECT (s->n_type))
+ /* A pointer to the referenced symbol will be stored in the udata
+ field. Use that to find the string index. */
+ s->symbol.value =
+ ((bfd_mach_o_asymbol *)s->symbol.udata.p)->symbol.udata.i;
+
if (s->symbol.name == 0 || s->symbol.name[0] == '\0')
+ /* An index of 0 always means the empty string. */
str_index = 0;
else
{
str_index = _bfd_stringtab_add (strtab, s->symbol.name, TRUE, FALSE);
+ /* Record the string index. This can be looked up by an indirect sym
+ which retains a pointer to its referenced counterpart, until it is
+ actually output. */
+ if (IS_MACHO_INDIRECT (s->n_type))
+ s->symbol.udata.i = str_index;
+
if (str_index == (bfd_size_type) -1)
goto err;
}
return FALSE;
}
-/* Process the symbols and generate Mach-O specific fields.
- Number them. */
+/* Write a dysymtab command.
+ TODO: Possibly coalesce writes of smaller objects. */
+
+static bfd_boolean
+bfd_mach_o_write_dysymtab (bfd *abfd, bfd_mach_o_load_command *command)
+{
+ bfd_mach_o_dysymtab_command *cmd = &command->command.dysymtab;
+
+ BFD_ASSERT (command->type == BFD_MACH_O_LC_DYSYMTAB);
+
+ if (cmd->nmodtab != 0)
+ {
+ unsigned int i;
+
+ if (bfd_seek (abfd, cmd->modtaboff, SEEK_SET) != 0)
+ return FALSE;
+
+ for (i = 0; i < cmd->nmodtab; i++)
+ {
+ bfd_mach_o_dylib_module *module = &cmd->dylib_module[i];
+ unsigned int iinit;
+ unsigned int ninit;
+
+ iinit = module->iinit & 0xffff;
+ iinit |= ((module->iterm & 0xffff) << 16);
+
+ ninit = module->ninit & 0xffff;
+ ninit |= ((module->nterm & 0xffff) << 16);
+
+ if (bfd_mach_o_wide_p (abfd))
+ {
+ struct mach_o_dylib_module_64_external w;
+
+ bfd_h_put_32 (abfd, module->module_name_idx, &w.module_name);
+ bfd_h_put_32 (abfd, module->iextdefsym, &w.iextdefsym);
+ bfd_h_put_32 (abfd, module->nextdefsym, &w.nextdefsym);
+ bfd_h_put_32 (abfd, module->irefsym, &w.irefsym);
+ bfd_h_put_32 (abfd, module->nrefsym, &w.nrefsym);
+ bfd_h_put_32 (abfd, module->ilocalsym, &w.ilocalsym);
+ bfd_h_put_32 (abfd, module->nlocalsym, &w.nlocalsym);
+ bfd_h_put_32 (abfd, module->iextrel, &w.iextrel);
+ bfd_h_put_32 (abfd, module->nextrel, &w.nextrel);
+ bfd_h_put_32 (abfd, iinit, &w.iinit_iterm);
+ bfd_h_put_32 (abfd, ninit, &w.ninit_nterm);
+ bfd_h_put_64 (abfd, module->objc_module_info_addr,
+ &w.objc_module_info_addr);
+ bfd_h_put_32 (abfd, module->objc_module_info_size,
+ &w.objc_module_info_size);
+
+ if (bfd_bwrite ((void *) &w, sizeof (w), abfd) != sizeof (w))
+ return FALSE;
+ }
+ else
+ {
+ struct mach_o_dylib_module_external n;
+
+ bfd_h_put_32 (abfd, module->module_name_idx, &n.module_name);
+ bfd_h_put_32 (abfd, module->iextdefsym, &n.iextdefsym);
+ bfd_h_put_32 (abfd, module->nextdefsym, &n.nextdefsym);
+ bfd_h_put_32 (abfd, module->irefsym, &n.irefsym);
+ bfd_h_put_32 (abfd, module->nrefsym, &n.nrefsym);
+ bfd_h_put_32 (abfd, module->ilocalsym, &n.ilocalsym);
+ bfd_h_put_32 (abfd, module->nlocalsym, &n.nlocalsym);
+ bfd_h_put_32 (abfd, module->iextrel, &n.iextrel);
+ bfd_h_put_32 (abfd, module->nextrel, &n.nextrel);
+ bfd_h_put_32 (abfd, iinit, &n.iinit_iterm);
+ bfd_h_put_32 (abfd, ninit, &n.ninit_nterm);
+ bfd_h_put_32 (abfd, module->objc_module_info_addr,
+ &n.objc_module_info_addr);
+ bfd_h_put_32 (abfd, module->objc_module_info_size,
+ &n.objc_module_info_size);
+
+ if (bfd_bwrite ((void *) &n, sizeof (n), abfd) != sizeof (n))
+ return FALSE;
+ }
+ }
+ }
+
+ if (cmd->ntoc != 0)
+ {
+ unsigned int i;
+
+ if (bfd_seek (abfd, cmd->tocoff, SEEK_SET) != 0)
+ return FALSE;
+
+ for (i = 0; i < cmd->ntoc; i++)
+ {
+ struct mach_o_dylib_table_of_contents_external raw;
+ bfd_mach_o_dylib_table_of_content *toc = &cmd->dylib_toc[i];
+
+ bfd_h_put_32 (abfd, toc->symbol_index, &raw.symbol_index);
+ bfd_h_put_32 (abfd, toc->module_index, &raw.module_index);
+
+ if (bfd_bwrite (&raw, sizeof (raw), abfd) != sizeof (raw))
+ return FALSE;
+ }
+ }
+
+ if (cmd->nindirectsyms > 0)
+ {
+ unsigned int i;
+
+ if (bfd_seek (abfd, cmd->indirectsymoff, SEEK_SET) != 0)
+ return FALSE;
+
+ for (i = 0; i < cmd->nindirectsyms; ++i)
+ {
+ unsigned char raw[4];
+
+ bfd_h_put_32 (abfd, cmd->indirect_syms[i], &raw);
+ if (bfd_bwrite (raw, sizeof (raw), abfd) != sizeof (raw))
+ return FALSE;
+ }
+ }
+
+ if (cmd->nextrefsyms != 0)
+ {
+ unsigned int i;
+
+ if (bfd_seek (abfd, cmd->extrefsymoff, SEEK_SET) != 0)
+ return FALSE;
+
+ for (i = 0; i < cmd->nextrefsyms; i++)
+ {
+ unsigned long v;
+ unsigned char raw[4];
+ bfd_mach_o_dylib_reference *ref = &cmd->ext_refs[i];
+
+ /* Fields isym and flags are written as bit-fields, thus we need
+ a specific processing for endianness. */
+
+ if (bfd_big_endian (abfd))
+ {
+ v = ((ref->isym & 0xffffff) << 8);
+ v |= ref->flags & 0xff;
+ }
+ else
+ {
+ v = ref->isym & 0xffffff;
+ v |= ((ref->flags & 0xff) << 24);
+ }
+
+ bfd_h_put_32 (abfd, v, raw);
+ if (bfd_bwrite (raw, sizeof (raw), abfd) != sizeof (raw))
+ return FALSE;
+ }
+ }
+
+ /* The command. */
+ if (bfd_seek (abfd, command->offset + BFD_MACH_O_LC_SIZE, SEEK_SET) != 0)
+ return FALSE;
+ else
+ {
+ struct mach_o_dysymtab_command_external raw;
+
+ bfd_h_put_32 (abfd, cmd->ilocalsym, &raw.ilocalsym);
+ bfd_h_put_32 (abfd, cmd->nlocalsym, &raw.nlocalsym);
+ bfd_h_put_32 (abfd, cmd->iextdefsym, &raw.iextdefsym);
+ bfd_h_put_32 (abfd, cmd->nextdefsym, &raw.nextdefsym);
+ bfd_h_put_32 (abfd, cmd->iundefsym, &raw.iundefsym);
+ bfd_h_put_32 (abfd, cmd->nundefsym, &raw.nundefsym);
+ bfd_h_put_32 (abfd, cmd->tocoff, &raw.tocoff);
+ bfd_h_put_32 (abfd, cmd->ntoc, &raw.ntoc);
+ bfd_h_put_32 (abfd, cmd->modtaboff, &raw.modtaboff);
+ bfd_h_put_32 (abfd, cmd->nmodtab, &raw.nmodtab);
+ bfd_h_put_32 (abfd, cmd->extrefsymoff, &raw.extrefsymoff);
+ bfd_h_put_32 (abfd, cmd->nextrefsyms, &raw.nextrefsyms);
+ bfd_h_put_32 (abfd, cmd->indirectsymoff, &raw.indirectsymoff);
+ bfd_h_put_32 (abfd, cmd->nindirectsyms, &raw.nindirectsyms);
+ bfd_h_put_32 (abfd, cmd->extreloff, &raw.extreloff);
+ bfd_h_put_32 (abfd, cmd->nextrel, &raw.nextrel);
+ bfd_h_put_32 (abfd, cmd->locreloff, &raw.locreloff);
+ bfd_h_put_32 (abfd, cmd->nlocrel, &raw.nlocrel);
+
+ if (bfd_bwrite (&raw, sizeof (raw), abfd) != sizeof (raw))
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+static unsigned
+bfd_mach_o_primary_symbol_sort_key (unsigned type, unsigned ext)
+{
+ /* TODO: Determine the correct ordering of stabs symbols. */
+ /* We make indirect symbols a local/synthetic. */
+ if (type == BFD_MACH_O_N_INDR)
+ return 3;
+
+ /* Local (we should never see an undefined local AFAICT). */
+ if (! ext)
+ return 0;
+
+ /* Common symbols look like undefined externs. */
+ if (type == BFD_MACH_O_N_UNDF)
+ return 2;
+
+ /* A defined symbol that's not indirect or extern. */
+ return 1;
+}
+
+static int
+bfd_mach_o_cf_symbols (const void *a, const void *b)
+{
+ bfd_mach_o_asymbol *sa = *(bfd_mach_o_asymbol **) a;
+ bfd_mach_o_asymbol *sb = *(bfd_mach_o_asymbol **) b;
+ unsigned int soa, sob;
+
+ soa = bfd_mach_o_primary_symbol_sort_key
+ (sa->n_type & BFD_MACH_O_N_TYPE,
+ sa->n_type & (BFD_MACH_O_N_PEXT | BFD_MACH_O_N_EXT));
+ sob = bfd_mach_o_primary_symbol_sort_key
+ (sb->n_type & BFD_MACH_O_N_TYPE,
+ sb->n_type & (BFD_MACH_O_N_PEXT | BFD_MACH_O_N_EXT));
+ if (soa < sob)
+ return -1;
+
+ if (soa > sob)
+ return 1;
+
+ /* If it's local, just preserve the input order. */
+ if (soa == 0)
+ {
+ if (sa->symbol.udata.i < sb->symbol.udata.i)
+ return -1;
+ if (sa->symbol.udata.i > sb->symbol.udata.i)
+ return 1;
+ return 0;
+ }
+
+ /* Unless it's an indirect the second sort key is name. */
+ if (soa < 3)
+ return strcmp (sa->symbol.name, sb->symbol.name);
+
+ /* Here be indirect symbols, which have different sort rules. */
+
+ /* Next sort key for indirect, is the section index. */
+ if (sa->n_sect < sb->n_sect)
+ return -1;
+
+ if (sa->n_sect > sb->n_sect)
+ return 1;
+
+ /* Last sort key is the order of definition - which should be in line with
+ the value, since a stub size of 0 is meaninglesss. */
+
+ if (sa->symbol.value < sb->symbol.value)
+ return -1;
+
+ if (sa->symbol.value > sb->symbol.value)
+ return 1;
+
+ /* In the final analysis, this is probably an error ... but leave it alone
+ for now. */
+ return 0;
+}
+
+/* When this is finished, return the number of non-indirect symbols. */
+
+static unsigned int
+bfd_mach_o_sort_symbol_table (asymbol **symbols, unsigned int nin)
+{
+ qsort (symbols, (size_t) nin, sizeof (void *), bfd_mach_o_cf_symbols);
+
+ /* Find the last non-indirect symbol.
+ There must be at least one non-indirect symbol otherwise there's
+ nothing for the indirect(s) to refer to. */
+ do
+ {
+ bfd_mach_o_asymbol *s = (bfd_mach_o_asymbol *)symbols[nin - 1];
+ if (IS_MACHO_INDIRECT (s->n_type))
+ nin--;
+ else
+ break;
+ } while (nin - 1 > 0);
+ return nin;
+}
+
+/* Process the symbols.
+
+ This should be OK for single-module files - but it is not likely to work
+ for multi-module shared libraries.
+
+ (a) If the application has not filled in the relevant mach-o fields, make
+ an estimate.
+
+ (b) Order them, like this:
+ ( i) local.
+ (unsorted)
+ ( ii) external defined
+ (by name)
+ (iii) external undefined
+ (by name)
+ ( iv) common
+ (by name)
+ ( v) indirect
+ (by section)
+ (by position within section).
+
+ (c) Indirect symbols are moved to the end of the list. */
static bfd_boolean
-bfd_mach_o_mangle_symbols (bfd *abfd)
+bfd_mach_o_mangle_symbols (bfd *abfd, bfd_mach_o_data_struct *mdata)
{
unsigned long i;
asymbol **symbols = bfd_get_outsymbols (abfd);
+ if (symbols == NULL || bfd_get_symcount (abfd) == 0)
+ return TRUE;
+
for (i = 0; i < bfd_get_symcount (abfd); i++)
{
bfd_mach_o_asymbol *s = (bfd_mach_o_asymbol *)symbols[i];
s->n_type = BFD_MACH_O_N_UNDF;
if (s->symbol.flags & BSF_WEAK)
s->n_desc |= BFD_MACH_O_N_WEAK_REF;
+ /* mach-o automatically makes undefined symbols extern. */
+ s->n_type |= BFD_MACH_O_N_EXT;
}
else if (s->symbol.section == bfd_com_section_ptr)
s->n_type = BFD_MACH_O_N_UNDF | BFD_MACH_O_N_EXT;
s->n_type |= BFD_MACH_O_N_EXT;
}
- /* Compute section index. */
+ /* Put the section index in, where required. */
if (s->symbol.section != bfd_abs_section_ptr
&& s->symbol.section != bfd_und_section_ptr
&& s->symbol.section != bfd_com_section_ptr)
s->n_sect = s->symbol.section->target_index;
- /* Number symbols. */
- s->symbol.udata.i = i;
+ /* Unless we're looking at an indirect sym, note the input ordering.
+ We use this to keep local symbols ordered as per the input. */
+ if (IS_MACHO_INDIRECT (s->n_type))
+ s->symbol.udata.i = i;
+ }
+
+ /* Sort the symbols and determine how many will remain in the main symbol
+ table, and how many will be emitted as indirect (assuming that we will
+ be emitting a dysymtab). Renumber the sorted symbols so that the right
+ index will be found during indirection. */
+ i = bfd_mach_o_sort_symbol_table (symbols, bfd_get_symcount (abfd));
+ if (bfd_mach_o_should_emit_dysymtab ())
+ {
+ /* Point at the first indirect symbol. */
+ if (i < bfd_get_symcount (abfd))
+ {
+ mdata->indirect_syms = &symbols[i];
+ mdata->nindirect = bfd_get_symcount (abfd) - i;
+ /* This is, essentially, local to the output section of mach-o,
+ and therefore should be safe. */
+ abfd->symcount = i;
+ }
+
+ /* Now setup the counts for each type of symbol. */
+ for (i = 0; i < bfd_get_symcount (abfd); ++i)
+ {
+ bfd_mach_o_asymbol *s = (bfd_mach_o_asymbol *)symbols[i];
+ s->symbol.udata.i = i; /* renumber. */
+ if (s->n_type & (BFD_MACH_O_N_EXT | BFD_MACH_O_N_PEXT))
+ break;
+ }
+ mdata->nlocal = i;
+ for (; i < bfd_get_symcount (abfd); ++i)
+ {
+ bfd_mach_o_asymbol *s = (bfd_mach_o_asymbol *)symbols[i];
+ s->symbol.udata.i = i; /* renumber. */
+ if ((s->n_type & BFD_MACH_O_N_TYPE) == BFD_MACH_O_N_UNDF)
+ break;
+ }
+ mdata->ndefext = i - mdata->nlocal;
+ mdata->nundefext = bfd_get_symcount (abfd)
+ - mdata->ndefext
+ - mdata->nlocal;
+ for (; i < bfd_get_symcount (abfd); ++i)
+ {
+ bfd_mach_o_asymbol *s = (bfd_mach_o_asymbol *)symbols[i];
+ s->symbol.udata.i = i; /* renumber. */
+ }
+ }
+
+ return TRUE;
+}
+
+/* We build a flat table of sections, which can be re-ordered if necessary.
+ Fill in the section number and other mach-o-specific data. */
+
+static bfd_boolean
+bfd_mach_o_mangle_sections (bfd *abfd, bfd_mach_o_data_struct *mdata)
+{
+ asection *sec;
+ unsigned target_index;
+ unsigned nsect;
+
+ nsect = bfd_count_sections (abfd);
+
+ /* Don't do it if it's already set - assume the application knows what it's
+ doing. */
+ if (mdata->nsects == nsect
+ && (mdata->nsects == 0 || mdata->sections != NULL))
+ return TRUE;
+
+ mdata->nsects = nsect;
+ mdata->sections = bfd_alloc (abfd,
+ mdata->nsects * sizeof (bfd_mach_o_section *));
+ if (mdata->sections == NULL)
+ return FALSE;
+
+ /* We need to check that this can be done... */
+ if (nsect > 255)
+ (*_bfd_error_handler) (_("mach-o: there are too many sections (%d)"
+ " maximum is 255,\n"), nsect);
+
+ /* Create Mach-O sections.
+ Section type, attribute and align should have been set when the
+ section was created - either read in or specified. */
+ target_index = 0;
+ for (sec = abfd->sections; sec; sec = sec->next)
+ {
+ unsigned bfd_align = bfd_get_section_alignment (abfd, sec);
+ bfd_mach_o_section *msect = bfd_mach_o_get_mach_o_section (sec);
+
+ mdata->sections[target_index] = msect;
+
+ msect->addr = bfd_get_section_vma (abfd, sec);
+ msect->size = bfd_get_section_size (sec);
+
+ /* Use the largest alignment set, in case it was bumped after the
+ section was created. */
+ msect->align = msect->align > bfd_align ? msect->align : bfd_align;
+
+ msect->offset = 0;
+ sec->target_index = ++target_index;
}
+
return TRUE;
}
unsigned int i;
bfd_mach_o_data_struct *mdata = bfd_mach_o_get_data (abfd);
+ /* Make the commands, if not already present. */
if (mdata->header.ncmds == 0)
if (!bfd_mach_o_build_commands (abfd))
return FALSE;
- /* Now write header information. */
- if (mdata->header.filetype == 0)
- {
- if (abfd->flags & EXEC_P)
- mdata->header.filetype = BFD_MACH_O_MH_EXECUTE;
- else if (abfd->flags & DYNAMIC)
- mdata->header.filetype = BFD_MACH_O_MH_DYLIB;
- else
- mdata->header.filetype = BFD_MACH_O_MH_OBJECT;
- }
if (!bfd_mach_o_write_header (abfd, &mdata->header))
return FALSE;
- /* Assign a number to each symbols. */
- if (!bfd_mach_o_mangle_symbols (abfd))
- return FALSE;
-
for (i = 0; i < mdata->header.ncmds; i++)
{
struct mach_o_load_command_external raw;
if (!bfd_mach_o_write_symtab (abfd, cur))
return FALSE;
break;
+ case BFD_MACH_O_LC_DYSYMTAB:
+ if (!bfd_mach_o_write_dysymtab (abfd, cur))
+ return FALSE;
+ break;
case BFD_MACH_O_LC_SYMSEG:
break;
case BFD_MACH_O_LC_THREAD:
case BFD_MACH_O_LC_IDENT:
case BFD_MACH_O_LC_FVMFILE:
case BFD_MACH_O_LC_PREPAGE:
- case BFD_MACH_O_LC_DYSYMTAB:
case BFD_MACH_O_LC_LOAD_DYLIB:
case BFD_MACH_O_LC_LOAD_WEAK_DYLIB:
case BFD_MACH_O_LC_ID_DYLIB:
s->flags = BFD_MACH_O_S_REGULAR;
}
-/* Build Mach-O load commands from the sections. */
+/* Count the number of sections in the list for the segment named.
+
+ The special case of NULL or "" for the segment name is valid for
+ an MH_OBJECT file and means 'all sections available'.
+
+ Requires that the sections table in mdata be filled in.
+
+ Returns the number of sections (0 is valid).
+ Any number > 255 signals an invalid section count, although we will,
+ perhaps, allow the file to be written (in line with Darwin tools up
+ to XCode 4).
+
+ A section count of (unsigned long) -1 signals a definite error. */
+
+static unsigned long
+bfd_mach_o_count_sections_for_seg (const char *segment,
+ bfd_mach_o_data_struct *mdata)
+{
+ unsigned i,j;
+ if (mdata == NULL || mdata->sections == NULL)
+ return (unsigned long) -1;
+
+ /* The MH_OBJECT case, all sections are considered; Although nsects is
+ is an unsigned long, the maximum valid section count is 255 and this
+ will have been checked already by mangle_sections. */
+ if (segment == NULL || segment[0] == '\0')
+ return mdata->nsects;
+
+ /* Count the number of sections we see in this segment. */
+ j = 0;
+ for (i = 0; i < mdata->nsects; ++i)
+ {
+ bfd_mach_o_section *s = mdata->sections[i];
+ if (strncmp (segment, s->segname, BFD_MACH_O_SEGNAME_SIZE) == 0)
+ j++;
+ }
+ return j;
+}
+
+static bfd_boolean
+bfd_mach_o_build_seg_command (const char *segment,
+ bfd_mach_o_data_struct *mdata,
+ bfd_mach_o_segment_command *seg)
+{
+ unsigned i;
+ int is_mho = (segment == NULL || segment[0] == '\0');
+
+ /* Fill segment command. */
+ if (is_mho)
+ memset (seg->segname, 0, sizeof (seg->segname));
+ else
+ strncpy (seg->segname, segment, sizeof (seg->segname));
+
+ /* TODO: fix this up for non-MH_OBJECT cases. */
+ seg->vmaddr = 0;
+
+ seg->fileoff = mdata->filelen;
+ seg->filesize = 0;
+ seg->maxprot = BFD_MACH_O_PROT_READ | BFD_MACH_O_PROT_WRITE
+ | BFD_MACH_O_PROT_EXECUTE;
+ seg->initprot = seg->maxprot;
+ seg->flags = 0;
+ seg->sect_head = NULL;
+ seg->sect_tail = NULL;
+
+ /* Append sections to the segment. */
+
+ for (i = 0; i < mdata->nsects; ++i)
+ {
+ bfd_mach_o_section *s = mdata->sections[i];
+ asection *sec = s->bfdsection;
+
+ /* If we're not making an MH_OBJECT, check whether this section is from
+ our segment, and skip if not. Otherwise, just add all sections. */
+ if (! is_mho
+ && strncmp (segment, s->segname, BFD_MACH_O_SEGNAME_SIZE) != 0)
+ continue;
+
+ bfd_mach_o_append_section_to_segment (seg, sec);
+
+ if (s->size == 0)
+ s->offset = 0;
+ else
+ {
+ mdata->filelen = FILE_ALIGN (mdata->filelen, s->align);
+ s->offset = mdata->filelen;
+ }
+
+ sec->filepos = s->offset;
+
+ mdata->filelen += s->size;
+ }
+
+ seg->filesize = mdata->filelen - seg->fileoff;
+ seg->vmsize = seg->filesize;
+
+ return TRUE;
+}
+
+static bfd_boolean
+bfd_mach_o_build_dysymtab_command (bfd *abfd,
+ bfd_mach_o_data_struct *mdata,
+ bfd_mach_o_load_command *cmd)
+{
+ bfd_mach_o_dysymtab_command *dsym = &cmd->command.dysymtab;
+
+ /* TODO:
+ We are not going to try and fill these in yet and, moreover, we are
+ going to bail if they are already set. */
+ if (dsym->nmodtab != 0
+ || dsym->ntoc != 0
+ || dsym->nextrefsyms != 0)
+ {
+ (*_bfd_error_handler) (_("sorry: modtab, toc and extrefsyms are not yet"
+ " implemented for dysymtab commands."));
+ return FALSE;
+ }
+
+ dsym->ilocalsym = 0;
+ dsym->nlocalsym = mdata->nlocal;
+ dsym->iextdefsym = dsym->nlocalsym;
+ dsym->nextdefsym = mdata->ndefext;
+ dsym->iundefsym = dsym->nextdefsym + dsym->iextdefsym;
+ dsym->nundefsym = mdata->nundefext;
+
+ if (mdata->nindirect > 0)
+ {
+ unsigned i, sect;
+
+ mdata->filelen = FILE_ALIGN (mdata->filelen, 2);
+ dsym->indirectsymoff = mdata->filelen;
+ mdata->filelen += mdata->nindirect * 4;
+
+ dsym->indirect_syms = bfd_zalloc (abfd, mdata->nindirect * 4);
+ if (dsym->indirect_syms == NULL)
+ return FALSE;
+ dsym->nindirectsyms = mdata->nindirect;
+
+ /* So fill in the indices, and point the section reserved1 fields
+ at the right one. */
+ sect = (unsigned) -1;
+ for (i = 0; i < mdata->nindirect; ++i)
+ {
+ bfd_mach_o_asymbol *s =
+ (bfd_mach_o_asymbol *) mdata->indirect_syms[i];
+ /* Lookup the index of the referenced symbol. */
+ dsym->indirect_syms[i] =
+ ((bfd_mach_o_asymbol *) s->symbol.udata.p)->symbol.udata.i;
+ if (s->n_sect != sect)
+ {
+ /* Mach-o sections are 1-based, but the section table
+ is 0-based. */
+ bfd_mach_o_section *sc = mdata->sections[s->n_sect-1];
+ sc->reserved1 = i;
+ sect = s->n_sect;
+ }
+ }
+ }
+
+ return TRUE;
+}
+
+/* Build Mach-O load commands (currently assuming an MH_OBJECT file).
+ TODO: Other file formats, rebuilding symtab/dysymtab commands for strip
+ and copy functionality. */
bfd_boolean
bfd_mach_o_build_commands (bfd *abfd)
bfd_mach_o_data_struct *mdata = bfd_mach_o_get_data (abfd);
unsigned int wide = mach_o_wide_p (&mdata->header);
bfd_mach_o_segment_command *seg;
- asection *sec;
bfd_mach_o_load_command *cmd;
bfd_mach_o_load_command *symtab_cmd;
- int target_index;
+ unsigned symcind;
- /* Return now if commands are already built. */
+ /* Return now if commands are already present. */
if (mdata->header.ncmds)
return FALSE;
- /* Very simple version: a command (segment) to contain all the sections and
- a command for the symbol table. */
- mdata->header.ncmds = 2;
- mdata->commands = bfd_alloc (abfd, mdata->header.ncmds
- * sizeof (bfd_mach_o_load_command));
- if (mdata->commands == NULL)
- return FALSE;
- cmd = &mdata->commands[0];
- seg = &cmd->command.segment;
-
- seg->nsects = bfd_count_sections (abfd);
+ /* Fill in the file type, if not already set. */
- /* Set segment command. */
- if (wide)
+ if (mdata->header.filetype == 0)
{
- cmd->type = BFD_MACH_O_LC_SEGMENT_64;
- cmd->offset = BFD_MACH_O_HEADER_64_SIZE;
- cmd->len = BFD_MACH_O_LC_SEGMENT_64_SIZE
- + BFD_MACH_O_SECTION_64_SIZE * seg->nsects;
+ if (abfd->flags & EXEC_P)
+ mdata->header.filetype = BFD_MACH_O_MH_EXECUTE;
+ else if (abfd->flags & DYNAMIC)
+ mdata->header.filetype = BFD_MACH_O_MH_DYLIB;
+ else
+ mdata->header.filetype = BFD_MACH_O_MH_OBJECT;
}
- else
+
+ /* If hasn't already been done, flatten sections list, and sort
+ if/when required. Must be done before the symbol table is adjusted,
+ since that depends on properly numbered sections. */
+ if (mdata->nsects == 0 || mdata->sections == NULL)
+ if (! bfd_mach_o_mangle_sections (abfd, mdata))
+ return FALSE;
+
+ /* Order the symbol table, fill-in/check mach-o specific fields and
+ partition out any indirect symbols. */
+ if (!bfd_mach_o_mangle_symbols (abfd, mdata))
+ return FALSE;
+
+ /* It's valid to have a file with only absolute symbols... */
+ if (mdata->nsects > 0)
{
- cmd->type = BFD_MACH_O_LC_SEGMENT;
- cmd->offset = BFD_MACH_O_HEADER_SIZE;
- cmd->len = BFD_MACH_O_LC_SEGMENT_SIZE
- + BFD_MACH_O_SECTION_SIZE * seg->nsects;
+ mdata->header.ncmds = 1;
+ symcind = 1;
}
- cmd->type_required = FALSE;
- mdata->header.sizeofcmds = cmd->len;
- mdata->filelen = cmd->offset + cmd->len;
+ else
+ symcind = 0;
- /* Set symtab command. */
- symtab_cmd = &mdata->commands[1];
-
- symtab_cmd->type = BFD_MACH_O_LC_SYMTAB;
- symtab_cmd->offset = cmd->offset + cmd->len;
- symtab_cmd->len = 6 * 4;
- symtab_cmd->type_required = FALSE;
-
- mdata->header.sizeofcmds += symtab_cmd->len;
- mdata->filelen += symtab_cmd->len;
+ /* It's OK to have a file with only section statements. */
+ if (bfd_get_symcount (abfd) > 0)
+ mdata->header.ncmds += 1;
- /* Fill segment command. */
- memset (seg->segname, 0, sizeof (seg->segname));
- seg->vmaddr = 0;
- seg->fileoff = mdata->filelen;
- seg->filesize = 0;
- seg->maxprot = BFD_MACH_O_PROT_READ | BFD_MACH_O_PROT_WRITE
- | BFD_MACH_O_PROT_EXECUTE;
- seg->initprot = seg->maxprot;
- seg->flags = 0;
- seg->sect_head = NULL;
- seg->sect_tail = NULL;
+ /* Very simple version (only really applicable to MH_OBJECTs):
+ a command (segment) to contain all the sections,
+ a command for the symbol table
+ a n (optional) command for the dysymtab.
- /* Create Mach-O sections.
- Section type, attribute and align should have been set when the
- section was created - either read in or specified. */
- target_index = 0;
- for (sec = abfd->sections; sec; sec = sec->next)
- {
- unsigned bfd_align = bfd_get_section_alignment (abfd, sec);
- bfd_mach_o_section *msect = bfd_mach_o_get_mach_o_section (sec);
+ ??? maybe we should assert that this is an MH_OBJECT? */
- bfd_mach_o_append_section_to_segment (seg, sec);
+ if (bfd_mach_o_should_emit_dysymtab ()
+ && bfd_get_symcount (abfd) > 0)
+ mdata->header.ncmds += 1;
- msect->addr = bfd_get_section_vma (abfd, sec);
- msect->size = bfd_get_section_size (sec);
- /* Use the largest alignment set, in case it was bumped after the
- section was created. */
- msect->align = msect->align > bfd_align ? msect->align : bfd_align;
+ /* A bit weird, but looks like no content;
+ as -n empty.s -o empty.o */
+ if (mdata->header.ncmds == 0)
+ return TRUE;
- if (msect->size != 0)
- {
- mdata->filelen = FILE_ALIGN (mdata->filelen, msect->align);
- msect->offset = mdata->filelen;
- }
+ mdata->commands = bfd_zalloc (abfd, mdata->header.ncmds
+ * sizeof (bfd_mach_o_load_command));
+ if (mdata->commands == NULL)
+ return FALSE;
+
+ if (mdata->nsects > 0)
+ {
+ cmd = &mdata->commands[0];
+ seg = &cmd->command.segment;
+
+ /* Count the segctions in the special blank segment used for MH_OBJECT. */
+ seg->nsects = bfd_mach_o_count_sections_for_seg (NULL, mdata);
+ if (seg->nsects == (unsigned long) -1)
+ return FALSE;
+
+ /* Init segment command. */
+ if (wide)
+ {
+ cmd->type = BFD_MACH_O_LC_SEGMENT_64;
+ cmd->offset = BFD_MACH_O_HEADER_64_SIZE;
+ cmd->len = BFD_MACH_O_LC_SEGMENT_64_SIZE
+ + BFD_MACH_O_SECTION_64_SIZE * seg->nsects;
+ }
else
- msect->offset = 0;
+ {
+ cmd->type = BFD_MACH_O_LC_SEGMENT;
+ cmd->offset = BFD_MACH_O_HEADER_SIZE;
+ cmd->len = BFD_MACH_O_LC_SEGMENT_SIZE
+ + BFD_MACH_O_SECTION_SIZE * seg->nsects;
+ }
+ cmd->type_required = FALSE;
+ mdata->header.sizeofcmds = cmd->len;
+ mdata->filelen = cmd->offset + cmd->len;
+ }
- sec->filepos = msect->offset;
- sec->target_index = ++target_index;
+ if (bfd_get_symcount (abfd) > 0)
+ {
+ /* Init symtab command. */
+ symtab_cmd = &mdata->commands[symcind];
+
+ symtab_cmd->type = BFD_MACH_O_LC_SYMTAB;
+ if (symcind > 0)
+ symtab_cmd->offset = mdata->commands[0].offset
+ + mdata->commands[0].len;
+ else
+ symtab_cmd->offset = 0;
+ symtab_cmd->len = 6 * 4;
+ symtab_cmd->type_required = FALSE;
+
+ mdata->header.sizeofcmds += symtab_cmd->len;
+ mdata->filelen += symtab_cmd->len;
+ }
- mdata->filelen += msect->size;
+ /* If required, setup symtab command. */
+ if (bfd_mach_o_should_emit_dysymtab ()
+ && bfd_get_symcount (abfd) > 0)
+ {
+ cmd = &mdata->commands[symcind+1];
+ cmd->type = BFD_MACH_O_LC_DYSYMTAB;
+ cmd->offset = symtab_cmd->offset + symtab_cmd->len;
+ cmd->type_required = FALSE;
+ cmd->len = 18 * 4 + BFD_MACH_O_LC_SIZE;
+
+ mdata->header.sizeofcmds += cmd->len;
+ mdata->filelen += cmd->len;
}
- seg->filesize = mdata->filelen - seg->fileoff;
- seg->vmsize = seg->filesize;
+ /* So, now we have sized the commands and the filelen set to that.
+ Now we can build the segment command and set the section file offsets. */
+ if (mdata->nsects > 0
+ && ! bfd_mach_o_build_seg_command (NULL, mdata, seg))
+ return FALSE;
+
+ /* If we're doing a dysymtab, cmd points to its load command. */
+ if (bfd_mach_o_should_emit_dysymtab ()
+ && bfd_get_symcount (abfd) > 0
+ && ! bfd_mach_o_build_dysymtab_command (abfd, mdata,
+ &mdata->commands[symcind+1]))
+ return FALSE;
+
+ /* The symtab command is filled in when the symtab is written. */
return TRUE;
}
{
file_ptr pos;
- /* This must be done first, because bfd_set_section_contents is
- going to set output_has_begun to TRUE. */
+ /* Trying to write the first section contents will trigger the creation of
+ the load commands if they are not already present. */
if (! abfd->output_has_begun && ! bfd_mach_o_build_commands (abfd))
return FALSE;
projects / external / binutils.git / blobdiff