diff options
Diffstat (limited to 'bfd')
| -rw-r--r-- | bfd/ChangeLog | 27 | ||||
| -rw-r--r-- | bfd/xcofflink.c | 289 |
2 files changed, 311 insertions, 5 deletions
diff --git a/bfd/ChangeLog b/bfd/ChangeLog index e7641b8..ced5285 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,30 @@ +Thu Nov 9 13:01:31 1995 Ian Lance Taylor <ian@cygnus.com> + + * xcofflink.c (XCOFF_DESCRIPTOR): Define. + (struct xcoff_link_hash_table): Add descriptor_section and + special_sections fields. + (_bfd_xcoff_bfd_link_hash_table_create): Initialize new fields. + (xcoff_link_add_symbols): Set linkage section alignment. Create + descriptor section. Check for magic symbol names (_text, etc.), + and record them in special_sections if found. Set + XCOFF_DESCRIPTOR flag for a function descriptor, and set its + descriptor field to point back to the function code symbol. + (xcoff_sweep): Always mark the special descriptor_section. + (bfd_xcoff_export_symbol): Check whether the symbol might be a + function descriptor, and mark it if it is. + (bfd_xcoff_size_dynamic_sections): Add new special_sections + parameter, and fill it in. Allocate space for the descriptor + section. + (xcoff_build_ldsyms): Set XCOFF_DEF_REGULAR flag when defining + global linkage code. If an undefined function descriptor is + exported, arrange to define it. Warn about any other undefined + exported symbol. + (_bfd_xcoff_bfd_final_link): Write out the descriptor section. + (xcoff_write_global_symbol): Create a function descriptor when + necessary. + * bfd-in.h (bfd_xcoff_size_dynamic_sections): Update declaration. + * bfd-in2.h: Rebuild. + Thu Nov 9 08:40:23 1995 Kim Knuttila <krk@cygnus.com> * coff-ppc.c (ppc_coff_link_hash_entry): new types for hashing diff --git a/bfd/xcofflink.c b/bfd/xcofflink.c index fd1ed7e..ca0b27b 100644 --- a/bfd/xcofflink.c +++ b/bfd/xcofflink.c @@ -261,7 +261,9 @@ struct xcoff_link_hash_entry } u; /* If this symbol is a function entry point which is called, this - field holds a pointer to the function descriptor. */ + field holds a pointer to the function descriptor. If this symbol + is a function descriptor, this field holds a pointer to the + function entry point. */ struct xcoff_link_hash_entry *descriptor; /* The .loader symbol table entry, if there is one. */ @@ -296,6 +298,8 @@ struct xcoff_link_hash_entry #define XCOFF_MARK (02000) /* Symbol size is recorded in size_list list from hash table. */ #define XCOFF_HAS_SIZE (04000) + /* Symbol is a function descriptor. */ +#define XCOFF_DESCRIPTOR (010000) /* The storage mapping class. */ unsigned char smclas; @@ -332,6 +336,10 @@ struct xcoff_link_hash_table linkage code. */ asection *toc_section; + /* The .ds section we use to hold function descriptors which we + create for exported symbols. */ + asection *descriptor_section; + /* The list of import files. */ struct xcoff_import_file *imports; @@ -351,6 +359,9 @@ struct xcoff_link_hash_table struct xcoff_link_hash_entry *h; bfd_size_type size; } *size_list; + + /* Magic sections: _text, _etext, _data, _edata, _end, end. */ + asection *special_sections[6]; }; /* Information we keep for each section in the output file during the @@ -627,10 +638,12 @@ _bfd_xcoff_bfd_link_hash_table_create (abfd) memset (&ret->ldhdr, 0, sizeof (struct internal_ldhdr)); ret->linkage_section = NULL; ret->toc_section = NULL; + ret->descriptor_section = NULL; ret->imports = NULL; ret->file_align = 0; ret->textro = false; ret->gc = false; + memset (ret->special_sections, 0, sizeof ret->special_sections); /* The linker will always generate a full a.out header. We need to record that fact now, before the sizeof_headers routine could be @@ -978,6 +991,7 @@ xcoff_link_add_symbols (abfd, info) goto error_return; xcoff_hash_table (info)->linkage_section = lsec; lsec->flags |= SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS | SEC_IN_MEMORY; + lsec->alignment_power = 2; } /* Likewise for the TOC section. */ if (xcoff_hash_table (info)->toc_section == NULL) @@ -991,6 +1005,18 @@ xcoff_link_add_symbols (abfd, info) tsec->flags |= SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS | SEC_IN_MEMORY; tsec->alignment_power = 2; } + /* Likewise for the descriptor section. */ + if (xcoff_hash_table (info)->descriptor_section == NULL) + { + asection *dsec; + + dsec = bfd_make_section_anyway (abfd, ".ds"); + if (dsec == NULL) + goto error_return; + xcoff_hash_table (info)->descriptor_section = dsec; + dsec->flags |= SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS | SEC_IN_MEMORY; + dsec->alignment_power = 2; + } /* Likewise for the .debug section. */ if (xcoff_hash_table (info)->debug_section == NULL) { @@ -1623,6 +1649,33 @@ xcoff_link_add_symbols (abfd, info) break; } + /* Check for magic symbol names. */ + if ((smtyp == XTY_SD || smtyp == XTY_CM) + && aux.x_csect.x_smclas != XMC_TC) + { + int i; + + i = -1; + if (name[0] == '_') + { + if (strcmp (name, "_text") == 0) + i = 0; + else if (strcmp (name, "_etext") == 0) + i = 1; + else if (strcmp (name, "_data") == 0) + i = 2; + else if (strcmp (name, "_edata") == 0) + i = 3; + else if (strcmp (name, "_end") == 0) + i = 4; + } + else if (name[0] == 'e' && strcmp (name, "end") == 0) + i = 5; + + if (i != -1) + xcoff_hash_table (info)->special_sections[i] = csect; + } + /* Now we have enough information to add the symbol to the linker hash table. */ @@ -1800,6 +1853,10 @@ xcoff_link_add_symbols (abfd, info) (struct bfd_link_hash_entry **) &hds))) goto error_return; } + hds->flags |= XCOFF_DESCRIPTOR; + BFD_ASSERT ((hds->flags & XCOFF_CALLED) == 0 + && (h->flags & XCOFF_DESCRIPTOR) == 0); + hds->descriptor = h; h->descriptor = hds; } } @@ -2250,6 +2307,7 @@ xcoff_sweep (info) || o == xcoff_hash_table (info)->loader_section || o == xcoff_hash_table (info)->linkage_section || o == xcoff_hash_table (info)->toc_section + || o == xcoff_hash_table (info)->descriptor_section || strcmp (o->name, ".debug") == 0) o->flags |= SEC_MARK; else @@ -2411,10 +2469,51 @@ bfd_xcoff_export_symbol (output_bfd, info, harg, syscall) /* FIXME: I'm not at all sure what syscall is supposed to mean, so I'm just going to ignore it until somebody explains it. */ + /* See if this is a function descriptor. It may be one even though + it is not so marked. */ + if ((h->flags & XCOFF_DESCRIPTOR) == 0 + && h->root.root.string[0] != '.') + { + char *fnname; + struct xcoff_link_hash_entry *hfn; + + fnname = (char *) malloc (strlen (h->root.root.string + 2)); + if (fnname == NULL) + { + bfd_set_error (bfd_error_no_memory); + return false; + } + fnname[0] = '.'; + strcpy (fnname + 1, h->root.root.string); + hfn = xcoff_link_hash_lookup (xcoff_hash_table (info), + fnname, false, false, true); + free (fnname); + if (hfn != NULL + && hfn->smclas == XMC_PR + && (hfn->root.type == bfd_link_hash_defined + || hfn->root.type == bfd_link_hash_defweak)) + { + h->flags |= XCOFF_DESCRIPTOR; + h->descriptor = hfn; + hfn->descriptor = h; + } + } + /* Make sure we don't garbage collect this symbol. */ if (! xcoff_mark_symbol (info, h)) return false; + /* If this is a function descriptor, make sure we don't garbage + collect the associated function code. We normally don't have to + worry about this, because the descriptor will be attached to a + section with relocs, but if we are creating the descriptor + ourselves those relocs will not be visible to the mark code. */ + if ((h->flags & XCOFF_DESCRIPTOR) != 0) + { + if (! xcoff_mark_symbol (info, h->descriptor)) + return false; + } + return true; } @@ -2507,7 +2606,7 @@ struct xcoff_loader_info boolean bfd_xcoff_size_dynamic_sections (output_bfd, info, libpath, entry, file_align, maxstack, maxdata, gc, - modtype, textro) + modtype, textro, special_sections) bfd *output_bfd; struct bfd_link_info *info; const char *libpath; @@ -2518,10 +2617,12 @@ bfd_xcoff_size_dynamic_sections (output_bfd, info, libpath, entry, boolean gc; int modtype; boolean textro; + asection **special_sections; { struct xcoff_link_hash_entry *hentry; asection *lsec; struct xcoff_loader_info ldinfo; + int i; size_t impsize, impcount; struct xcoff_import_file *fl; struct internal_ldhdr *ldhdr; @@ -2595,6 +2696,19 @@ bfd_xcoff_size_dynamic_sections (output_bfd, info, libpath, entry, xcoff_hash_table (info)->gc = true; } + /* Return special sections to the caller. */ + for (i = 0; i < 6; i++) + { + asection *sec; + + sec = xcoff_hash_table (info)->special_sections[i]; + if (sec != NULL + && gc + && (sec->flags & SEC_MARK) == 0) + sec = NULL; + special_sections[i] = sec; + } + if (info->input_bfds == NULL) { /* I'm not sure what to do in this bizarre case. */ @@ -2694,8 +2808,7 @@ bfd_xcoff_size_dynamic_sections (output_bfd, info, libpath, entry, when the corresponding normal relocs are handled in xcoff_link_input_bfd. */ - /* Allocate space for the global linkage section and the global toc - section. */ + /* Allocate space for the magic sections. */ sec = xcoff_hash_table (info)->linkage_section; if (sec->_raw_size > 0) { @@ -2716,6 +2829,16 @@ bfd_xcoff_size_dynamic_sections (output_bfd, info, libpath, entry, goto error_return; } } + sec = xcoff_hash_table (info)->descriptor_section; + if (sec->_raw_size > 0) + { + sec->contents = (bfd_byte *) bfd_zalloc (output_bfd, sec->_raw_size); + if (sec->contents == NULL) + { + bfd_set_error (bfd_error_no_memory); + goto error_return; + } + } /* Now that we've done garbage collection, figure out the contents of the .debug section. */ @@ -2877,6 +3000,7 @@ xcoff_build_ldsyms (h, p) h->root.u.def.section = sec; h->root.u.def.value = sec->_raw_size; h->smclas = XMC_GL; + h->flags |= XCOFF_DEF_REGULAR; sec->_raw_size += XCOFF_GLINK_SIZE; /* The global linkage code requires a TOC entry for the @@ -2902,6 +3026,53 @@ xcoff_build_ldsyms (h, p) } } + /* If this symbol is exported, but not defined, we need to try to + define it. */ + if ((h->flags & XCOFF_EXPORT) != 0 + && (h->flags & XCOFF_IMPORT) == 0 + && (h->flags & XCOFF_DEF_REGULAR) == 0 + && (h->flags & XCOFF_DEF_DYNAMIC) == 0 + && (h->root.type == bfd_link_hash_undefined + || h->root.type == bfd_link_hash_undefweak)) + { + if ((h->flags & XCOFF_DESCRIPTOR) != 0 + && (h->descriptor->root.type == bfd_link_hash_defined + || h->descriptor->root.type == bfd_link_hash_defweak)) + { + asection *sec; + + /* This is an undefined function descriptor associated with + a defined entry point. We can build up a function + descriptor ourselves. Believe it or not, the AIX linker + actually does this, and there are cases where we need to + do it as well. */ + sec = xcoff_hash_table (ldinfo->info)->descriptor_section; + h->root.type = bfd_link_hash_defined; + h->root.u.def.section = sec; + h->root.u.def.value = sec->_raw_size; + h->smclas = XMC_DS; + h->flags |= XCOFF_DEF_REGULAR; + sec->_raw_size += 12; + + /* A function descriptor uses two relocs: one for the + associated code, and one for the TOC address. */ + xcoff_hash_table (ldinfo->info)->ldrel_count += 2; + sec->reloc_count += 2; + + /* We handle writing out the contents of the descriptor in + xcoff_write_global_symbol. */ + } + else + { + (*_bfd_error_handler) + ("attempt to export undefined symbol `%s'", + h->root.root.string); + ldinfo->failed = true; + bfd_set_error (bfd_error_invalid_operation); + return false; + } + } + /* If this is still a common symbol, and it wasn't garbage collected, we need to actually allocate space for it in the .bss section. */ @@ -3528,7 +3699,7 @@ _bfd_xcoff_bfd_final_link (abfd, info) o->_raw_size)) goto error_return; - /* Write out the global linkage section and the toc section. */ + /* Write out the magic sections. */ o = xcoff_hash_table (info)->linkage_section; if (o->_raw_size > 0 && ! bfd_set_section_contents (abfd, o->output_section, o->contents, @@ -3539,6 +3710,11 @@ _bfd_xcoff_bfd_final_link (abfd, info) && ! bfd_set_section_contents (abfd, o->output_section, o->contents, o->output_offset, o->_raw_size)) goto error_return; + o = xcoff_hash_table (info)->descriptor_section; + if (o->_raw_size > 0 + && ! bfd_set_section_contents (abfd, o->output_section, o->contents, + o->output_offset, o->_raw_size)) + goto error_return; /* Write out the string table. */ if (bfd_seek (abfd, @@ -4857,6 +5033,109 @@ xcoff_write_global_symbol (h, p) ++finfo->ldrel; } + /* If this symbol is a specially defined function descriptor, write + it out. The first word is the address of the function code + itself, the second word is the address of the TOC, and the third + word is zero. */ + if ((h->flags & XCOFF_DESCRIPTOR) != 0 + && h->root.type == bfd_link_hash_defined + && (h->root.u.def.section + == xcoff_hash_table (finfo->info)->descriptor_section)) + { + asection *sec; + asection *osec; + int oindx; + bfd_byte *p; + struct xcoff_link_hash_entry *hentry; + asection *esec; + struct internal_reloc *irel; + struct internal_ldrel ldrel; + asection *tsec; + + sec = h->root.u.def.section; + osec = sec->output_section; + oindx = osec->target_index; + p = sec->contents + h->root.u.def.value; + + hentry = h->descriptor; + BFD_ASSERT (hentry != NULL + && (hentry->root.type == bfd_link_hash_defined + || hentry->root.type == bfd_link_hash_defweak)); + esec = hentry->root.u.def.section; + bfd_put_32 (output_bfd, + (esec->output_section->vma + + esec->output_offset + + hentry->root.u.def.value), + p); + + irel = finfo->section_info[oindx].relocs + osec->reloc_count; + irel->r_vaddr = (osec->vma + + sec->output_offset + + h->root.u.def.value); + irel->r_symndx = esec->output_section->target_index; + irel->r_type = R_POS; + irel->r_size = 31; + finfo->section_info[oindx].rel_hashes[osec->reloc_count] = NULL; + ++osec->reloc_count; + + ldrel.l_vaddr = irel->r_vaddr; + if (strcmp (esec->output_section->name, ".text") == 0) + ldrel.l_symndx = 0; + else if (strcmp (esec->output_section->name, ".data") == 0) + ldrel.l_symndx = 1; + else if (strcmp (esec->output_section->name, ".bss") == 0) + ldrel.l_symndx = 2; + else + { + (*_bfd_error_handler) + ("%s: loader reloc in unrecognized section `%s'", + bfd_get_filename (output_bfd), + esec->output_section->name); + bfd_set_error (bfd_error_nonrepresentable_section); + return false; + } + ldrel.l_rtype = (31 << 8) | R_POS; + ldrel.l_rsecnm = oindx; + xcoff_swap_ldrel_out (output_bfd, &ldrel, finfo->ldrel); + ++finfo->ldrel; + + bfd_put_32 (output_bfd, xcoff_data (output_bfd)->toc, p + 4); + + tsec = xcoff_data (output_bfd)->toc_section; + + ++irel; + irel->r_vaddr = (osec->vma + + sec->output_offset + + h->root.u.def.value + + 4); + irel->r_symndx = tsec->output_section->target_index; + irel->r_type = R_POS; + irel->r_size = 31; + finfo->section_info[oindx].rel_hashes[osec->reloc_count] = NULL; + ++osec->reloc_count; + + ldrel.l_vaddr = irel->r_vaddr; + if (strcmp (tsec->output_section->name, ".text") == 0) + ldrel.l_symndx = 0; + else if (strcmp (tsec->output_section->name, ".data") == 0) + ldrel.l_symndx = 1; + else if (strcmp (tsec->output_section->name, ".bss") == 0) + ldrel.l_symndx = 2; + else + { + (*_bfd_error_handler) + ("%s: loader reloc in unrecognized section `%s'", + bfd_get_filename (output_bfd), + tsec->output_section->name); + bfd_set_error (bfd_error_nonrepresentable_section); + return false; + } + ldrel.l_rtype = (31 << 8) | R_POS; + ldrel.l_rsecnm = oindx; + xcoff_swap_ldrel_out (output_bfd, &ldrel, finfo->ldrel); + ++finfo->ldrel; + } + if (h->indx >= 0) return true; |