diff options
Diffstat (limited to 'bfd/mach-o.c')
| -rw-r--r-- | bfd/mach-o.c | 126 |
1 files changed, 76 insertions, 50 deletions
diff --git a/bfd/mach-o.c b/bfd/mach-o.c index 1234899..307a8eb 100644 --- a/bfd/mach-o.c +++ b/bfd/mach-o.c @@ -2153,11 +2153,11 @@ 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 = NULL; - bfd_mach_o_load_command *cmd; - bfd_mach_o_load_command *symtab_cmd; - unsigned symcind; + unsigned wide = mach_o_wide_p (&mdata->header); + int segcmd_idx = -1; + int symtab_idx = -1; + int dysymtab_idx = -1; + unsigned long base_offset = 0; /* Return now if commands are already present. */ if (mdata->header.ncmds) @@ -2187,31 +2187,48 @@ bfd_mach_o_build_commands (bfd *abfd) if (!bfd_mach_o_mangle_symbols (abfd)) return FALSE; - /* It's valid to have a file with only absolute symbols... */ + /* Very simple command set (only really applicable to MH_OBJECTs): + All the commands are optional - present only when there is suitable data. + (i.e. it is valid to have an empty file) + + a command (segment) to contain all the sections, + command for the symbol table, + a command for the dysymtab. + + ??? maybe we should assert that this is an MH_OBJECT? */ + if (mdata->nsects > 0) { + segcmd_idx = 0; mdata->header.ncmds = 1; - symcind = 1; } - else - symcind = 0; - /* It's OK to have a file with only section statements. */ if (bfd_get_symcount (abfd) > 0) - mdata->header.ncmds += 1; + { + mdata->header.ncmds++; + symtab_idx = segcmd_idx + 1; /* 0 if the seg command is absent. */ + } - /* 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. + /* FIXME: + This is a rather crude test for whether we should build a dysymtab. */ + if (bfd_mach_o_should_emit_dysymtab () + && bfd_get_symcount (abfd)) + { + mdata->header.ncmds++; + /* If there should be a case where a dysymtab could be emitted without + a symtab (seems improbable), this would need amending. */ + dysymtab_idx = symtab_idx + 1; + } - ??? maybe we should assert that this is an MH_OBJECT? */ + if (wide) + base_offset = BFD_MACH_O_HEADER_64_SIZE; + else + base_offset = BFD_MACH_O_HEADER_SIZE; - if (bfd_mach_o_should_emit_dysymtab () - && bfd_get_symcount (abfd) > 0) - mdata->header.ncmds += 1; + /* Well, we must have a header, at least. */ + mdata->filelen = base_offset; - /* A bit weird, but looks like no content; + /* A bit unusual, but no content is valid; as -n empty.s -o empty.o */ if (mdata->header.ncmds == 0) return TRUE; @@ -2221,10 +2238,10 @@ bfd_mach_o_build_commands (bfd *abfd) if (mdata->commands == NULL) return FALSE; - if (mdata->nsects > 0) + if (segcmd_idx >= 0) { - cmd = &mdata->commands[0]; - seg = &cmd->command.segment; + bfd_mach_o_load_command *cmd = &mdata->commands[segcmd_idx]; + bfd_mach_o_segment_command *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); @@ -2232,52 +2249,61 @@ bfd_mach_o_build_commands (bfd *abfd) return FALSE; /* Init segment command. */ + cmd->offset = base_offset; 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 { 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; + mdata->filelen += cmd->len; } - if (bfd_get_symcount (abfd) > 0) + if (symtab_idx >= 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; + bfd_mach_o_load_command *cmd = &mdata->commands[symtab_idx]; - mdata->header.sizeofcmds += symtab_cmd->len; - mdata->filelen += symtab_cmd->len; + cmd->type = BFD_MACH_O_LC_SYMTAB; + cmd->offset = base_offset; + if (segcmd_idx >= 0) + cmd->offset += mdata->commands[segcmd_idx].len; + + cmd->len = sizeof (struct mach_o_symtab_command_external) + + BFD_MACH_O_LC_SIZE; + cmd->type_required = FALSE; + mdata->header.sizeofcmds += cmd->len; + mdata->filelen += cmd->len; } - /* If required, setup symtab command. */ - if (bfd_mach_o_should_emit_dysymtab () - && bfd_get_symcount (abfd) > 0) + /* If required, setup symtab command, see comment above about the quality + of this test. */ + if (dysymtab_idx >= 0) { - cmd = &mdata->commands[symcind+1]; + bfd_mach_o_load_command *cmd = &mdata->commands[dysymtab_idx]; + cmd->type = BFD_MACH_O_LC_DYSYMTAB; - cmd->offset = symtab_cmd->offset + symtab_cmd->len; + if (symtab_idx >= 0) + cmd->offset = mdata->commands[symtab_idx].offset + + mdata->commands[symtab_idx].len; + else if (segcmd_idx >= 0) + cmd->offset = mdata->commands[segcmd_idx].offset + + mdata->commands[segcmd_idx].len; + else + cmd->offset = base_offset; + cmd->type_required = FALSE; - cmd->len = 18 * 4 + BFD_MACH_O_LC_SIZE; + cmd->len = sizeof (struct mach_o_dysymtab_command_external) + + BFD_MACH_O_LC_SIZE; mdata->header.sizeofcmds += cmd->len; mdata->filelen += cmd->len; @@ -2285,15 +2311,15 @@ bfd_mach_o_build_commands (bfd *abfd) /* 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)) + if (segcmd_idx >= 0 + && ! bfd_mach_o_build_seg_command + (NULL, mdata, &mdata->commands[segcmd_idx].command.segment)) 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 + if (dysymtab_idx >= 0 && ! bfd_mach_o_build_dysymtab_command (abfd, mdata, - &mdata->commands[symcind+1])) + &mdata->commands[dysymtab_idx])) return FALSE; /* The symtab command is filled in when the symtab is written. */ |