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-rw-r--r--ld/ldwrite.c530
1 files changed, 530 insertions, 0 deletions
diff --git a/ld/ldwrite.c b/ld/ldwrite.c
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+++ b/ld/ldwrite.c
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+/* ldwrite.c -- write out the linked file
+ Copyright (C) 1991, 92, 93, 94, 95, 96, 97, 1998
+ Free Software Foundation, Inc.
+ Written by Steve Chamberlain sac@cygnus.com
+
+This file is part of GLD, the Gnu Linker.
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+
+#include "bfd.h"
+#include "sysdep.h"
+#include "bfdlink.h"
+#include "libiberty.h"
+
+#include "ld.h"
+#include "ldexp.h"
+#include "ldlang.h"
+#include "ldwrite.h"
+#include "ldmisc.h"
+#include "ldgram.h"
+#include "ldmain.h"
+
+static void build_link_order PARAMS ((lang_statement_union_type *));
+static asection *clone_section PARAMS ((bfd *, asection *, int *));
+static void split_sections PARAMS ((bfd *, struct bfd_link_info *));
+
+/* Build link_order structures for the BFD linker. */
+
+static void
+build_link_order (statement)
+ lang_statement_union_type *statement;
+{
+ switch (statement->header.type)
+ {
+ case lang_data_statement_enum:
+ {
+ asection *output_section;
+ struct bfd_link_order *link_order;
+ bfd_vma value;
+ boolean big_endian = false;
+
+ output_section = statement->data_statement.output_section;
+ ASSERT (output_section->owner == output_bfd);
+
+ link_order = bfd_new_link_order (output_bfd, output_section);
+ if (link_order == NULL)
+ einfo (_("%P%F: bfd_new_link_order failed\n"));
+
+ link_order->type = bfd_data_link_order;
+ link_order->offset = statement->data_statement.output_vma;
+ link_order->u.data.contents = (bfd_byte *) xmalloc (QUAD_SIZE);
+
+ value = statement->data_statement.value;
+
+ /* If the endianness of the output BFD is not known, then we
+ base the endianness of the data on the first input file.
+ By convention, the bfd_put routines for an unknown
+ endianness are big endian, so we must swap here if the
+ input file is little endian. */
+ if (bfd_big_endian (output_bfd))
+ big_endian = true;
+ else if (bfd_little_endian (output_bfd))
+ big_endian = false;
+ else
+ {
+ boolean swap;
+
+ swap = false;
+ if (command_line.endian == ENDIAN_BIG)
+ big_endian = true;
+ else if (command_line.endian == ENDIAN_LITTLE)
+ {
+ big_endian = false;
+ swap = true;
+ }
+ else if (command_line.endian == ENDIAN_UNSET)
+ {
+ big_endian = true;
+ {
+ LANG_FOR_EACH_INPUT_STATEMENT (s)
+ {
+ if (s->the_bfd != NULL)
+ {
+ if (bfd_little_endian (s->the_bfd))
+ {
+ big_endian = false;
+ swap = true;
+ }
+ break;
+ }
+ }
+ }
+ }
+
+ if (swap)
+ {
+ bfd_byte buffer[8];
+
+ switch (statement->data_statement.type)
+ {
+ case QUAD:
+ case SQUAD:
+ if (sizeof (bfd_vma) >= QUAD_SIZE)
+ {
+ bfd_putl64 (value, buffer);
+ value = bfd_getb64 (buffer);
+ break;
+ }
+ /* Fall through. */
+ case LONG:
+ bfd_putl32 (value, buffer);
+ value = bfd_getb32 (buffer);
+ break;
+ case SHORT:
+ bfd_putl16 (value, buffer);
+ value = bfd_getb16 (buffer);
+ break;
+ case BYTE:
+ break;
+ default:
+ abort ();
+ }
+ }
+ }
+
+ ASSERT (output_section->owner == output_bfd);
+ switch (statement->data_statement.type)
+ {
+ case QUAD:
+ case SQUAD:
+ if (sizeof (bfd_vma) >= QUAD_SIZE)
+ bfd_put_64 (output_bfd, value, link_order->u.data.contents);
+ else
+ {
+ bfd_vma high;
+
+ if (statement->data_statement.type == QUAD)
+ high = 0;
+ else if ((value & 0x80000000) == 0)
+ high = 0;
+ else
+ high = (bfd_vma) -1;
+ bfd_put_32 (output_bfd, high,
+ (link_order->u.data.contents
+ + (big_endian ? 0 : 4)));
+ bfd_put_32 (output_bfd, value,
+ (link_order->u.data.contents
+ + (big_endian ? 4 : 0)));
+ }
+ link_order->size = QUAD_SIZE;
+ break;
+ case LONG:
+ bfd_put_32 (output_bfd, value, link_order->u.data.contents);
+ link_order->size = LONG_SIZE;
+ break;
+ case SHORT:
+ bfd_put_16 (output_bfd, value, link_order->u.data.contents);
+ link_order->size = SHORT_SIZE;
+ break;
+ case BYTE:
+ bfd_put_8 (output_bfd, value, link_order->u.data.contents);
+ link_order->size = BYTE_SIZE;
+ break;
+ default:
+ abort ();
+ }
+ }
+ break;
+
+ case lang_reloc_statement_enum:
+ {
+ lang_reloc_statement_type *rs;
+ asection *output_section;
+ struct bfd_link_order *link_order;
+
+ rs = &statement->reloc_statement;
+
+ output_section = rs->output_section;
+ ASSERT (output_section->owner == output_bfd);
+
+ link_order = bfd_new_link_order (output_bfd, output_section);
+ if (link_order == NULL)
+ einfo (_("%P%F: bfd_new_link_order failed\n"));
+
+ link_order->offset = rs->output_vma;
+ link_order->size = bfd_get_reloc_size (rs->howto);
+
+ link_order->u.reloc.p =
+ ((struct bfd_link_order_reloc *)
+ xmalloc (sizeof (struct bfd_link_order_reloc)));
+
+ link_order->u.reloc.p->reloc = rs->reloc;
+ link_order->u.reloc.p->addend = rs->addend_value;
+
+ if (rs->name == NULL)
+ {
+ link_order->type = bfd_section_reloc_link_order;
+ if (rs->section->owner == output_bfd)
+ link_order->u.reloc.p->u.section = rs->section;
+ else
+ {
+ link_order->u.reloc.p->u.section = rs->section->output_section;
+ link_order->u.reloc.p->addend += rs->section->output_offset;
+ }
+ }
+ else
+ {
+ link_order->type = bfd_symbol_reloc_link_order;
+ link_order->u.reloc.p->u.name = rs->name;
+ }
+ }
+ break;
+
+ case lang_input_section_enum:
+ /* Create a new link_order in the output section with this
+ attached */
+ if (statement->input_section.ifile->just_syms_flag == false)
+ {
+ asection *i = statement->input_section.section;
+ asection *output_section = i->output_section;
+
+ ASSERT (output_section->owner == output_bfd);
+
+ if ((output_section->flags & SEC_HAS_CONTENTS) != 0)
+ {
+ struct bfd_link_order *link_order;
+
+ link_order = bfd_new_link_order (output_bfd, output_section);
+
+ if (i->flags & SEC_NEVER_LOAD)
+ {
+ /* We've got a never load section inside one which
+ is going to be output, we'll change it into a
+ fill link_order */
+ link_order->type = bfd_fill_link_order;
+ link_order->u.fill.value = 0;
+ }
+ else
+ {
+ link_order->type = bfd_indirect_link_order;
+ link_order->u.indirect.section = i;
+ ASSERT (i->output_section == output_section);
+ }
+ if (i->_cooked_size)
+ link_order->size = i->_cooked_size;
+ else
+ link_order->size = bfd_get_section_size_before_reloc (i);
+ link_order->offset = i->output_offset;
+ }
+ }
+ break;
+
+ case lang_padding_statement_enum:
+ /* Make a new link_order with the right filler */
+ {
+ asection *output_section;
+ struct bfd_link_order *link_order;
+
+ output_section = statement->padding_statement.output_section;
+ ASSERT (statement->padding_statement.output_section->owner
+ == output_bfd);
+ if ((output_section->flags & SEC_HAS_CONTENTS) != 0)
+ {
+ link_order = bfd_new_link_order (output_bfd, output_section);
+ link_order->type = bfd_fill_link_order;
+ link_order->size = statement->padding_statement.size;
+ link_order->offset = statement->padding_statement.output_offset;
+ link_order->u.fill.value = statement->padding_statement.fill;
+ }
+ }
+ break;
+
+ default:
+ /* All the other ones fall through */
+ break;
+ }
+}
+
+/* Call BFD to write out the linked file. */
+
+
+/**********************************************************************/
+
+
+/* Wander around the input sections, make sure that
+ we'll never try and create an output section with more relocs
+ than will fit.. Do this by always assuming the worst case, and
+ creating new output sections with all the right bits */
+#define TESTIT 1
+static asection *
+clone_section (abfd, s, count)
+ bfd *abfd;
+ asection *s;
+ int *count;
+{
+#define SSIZE 8
+ char sname[SSIZE]; /* ?? find the name for this size */
+ asection *n;
+ struct bfd_link_hash_entry *h;
+ /* Invent a section name - use first five
+ chars of base section name and a digit suffix */
+ do
+ {
+ unsigned int i;
+ char b[6];
+ for (i = 0; i < sizeof (b) - 1 && s->name[i]; i++)
+ b[i] = s->name[i];
+ b[i] = 0;
+ sprintf (sname, "%s%d", b, (*count)++);
+ }
+ while (bfd_get_section_by_name (abfd, sname));
+
+ n = bfd_make_section_anyway (abfd, xstrdup (sname));
+
+ /* Create a symbol of the same name */
+
+ h = bfd_link_hash_lookup (link_info.hash,
+ sname, true, true, false);
+ h->type = bfd_link_hash_defined;
+ h->u.def.value = 0;
+ h->u.def.section = n ;
+
+
+ n->flags = s->flags;
+ n->vma = s->vma;
+ n->user_set_vma = s->user_set_vma;
+ n->lma = s->lma;
+ n->_cooked_size = 0;
+ n->_raw_size = 0;
+ n->output_offset = s->output_offset;
+ n->output_section = n;
+ n->orelocation = 0;
+ n->reloc_count = 0;
+ n->alignment_power = s->alignment_power;
+ return n;
+}
+
+#if TESTING
+static void
+ds (s)
+ asection *s;
+{
+ struct bfd_link_order *l = s->link_order_head;
+ printf ("vma %x size %x\n", s->vma, s->_raw_size);
+ while (l)
+ {
+ if (l->type == bfd_indirect_link_order)
+ {
+ printf ("%8x %s\n", l->offset, l->u.indirect.section->owner->filename);
+ }
+ else
+ {
+ printf (_("%8x something else\n"), l->offset);
+ }
+ l = l->next;
+ }
+ printf ("\n");
+}
+dump (s, a1, a2)
+ char *s;
+ asection *a1;
+ asection *a2;
+{
+ printf ("%s\n", s);
+ ds (a1);
+ ds (a2);
+}
+
+static void
+sanity_check (abfd)
+ bfd *abfd;
+{
+ asection *s;
+ for (s = abfd->sections; s; s = s->next)
+ {
+ struct bfd_link_order *p;
+ bfd_vma prev = 0;
+ for (p = s->link_order_head; p; p = p->next)
+ {
+ if (p->offset > 100000)
+ abort ();
+ if (p->offset < prev)
+ abort ();
+ prev = p->offset;
+ }
+ }
+}
+#else
+#define sanity_check(a)
+#define dump(a, b, c)
+#endif
+
+static void
+split_sections (abfd, info)
+ bfd *abfd;
+ struct bfd_link_info *info;
+{
+ asection *original_sec;
+ int nsecs = abfd->section_count;
+ sanity_check (abfd);
+ /* look through all the original sections */
+ for (original_sec = abfd->sections;
+ original_sec && nsecs;
+ original_sec = original_sec->next, nsecs--)
+ {
+ boolean first = true;
+ int count = 0;
+ int lines = 0;
+ int relocs = 0;
+ struct bfd_link_order **pp;
+ bfd_vma vma = original_sec->vma;
+ bfd_vma shift_offset = 0;
+ asection *cursor = original_sec;
+
+ /* count up the relocations and line entries to see if
+ anything would be too big to fit */
+ for (pp = &(cursor->link_order_head); *pp; pp = &((*pp)->next))
+ {
+ struct bfd_link_order *p = *pp;
+ int thislines = 0;
+ int thisrelocs = 0;
+ if (p->type == bfd_indirect_link_order)
+ {
+ asection *sec;
+
+ sec = p->u.indirect.section;
+
+ if (info->strip == strip_none
+ || info->strip == strip_some)
+ thislines = sec->lineno_count;
+
+ if (info->relocateable)
+ thisrelocs = sec->reloc_count;
+
+ }
+ else if (info->relocateable
+ && (p->type == bfd_section_reloc_link_order
+ || p->type == bfd_symbol_reloc_link_order))
+ thisrelocs++;
+
+ if (! first
+ && (thisrelocs + relocs > config.split_by_reloc
+ || thislines + lines > config.split_by_reloc
+ || config.split_by_file))
+ {
+ /* create a new section and put this link order and the
+ following link orders into it */
+ struct bfd_link_order *l = p;
+ asection *n = clone_section (abfd, cursor, &count);
+ *pp = NULL; /* Snip off link orders from old section */
+ n->link_order_head = l; /* attach to new section */
+ pp = &n->link_order_head;
+
+ /* change the size of the original section and
+ update the vma of the new one */
+
+ dump ("before snip", cursor, n);
+
+ n->_raw_size = cursor->_raw_size - l->offset;
+ cursor->_raw_size = l->offset;
+
+ vma += cursor->_raw_size;
+ n->lma = n->vma = vma;
+
+ shift_offset = l->offset;
+
+ /* run down the chain and change the output section to
+ the right one, update the offsets too */
+
+ while (l)
+ {
+ l->offset -= shift_offset;
+ if (l->type == bfd_indirect_link_order)
+ {
+ l->u.indirect.section->output_section = n;
+ l->u.indirect.section->output_offset = l->offset;
+ }
+ l = l->next;
+ }
+ dump ("after snip", cursor, n);
+ cursor = n;
+ relocs = thisrelocs;
+ lines = thislines;
+ }
+ else
+ {
+ relocs += thisrelocs;
+ lines += thislines;
+ }
+
+ first = false;
+ }
+ }
+ sanity_check (abfd);
+}
+/**********************************************************************/
+void
+ldwrite ()
+{
+ /* Reset error indicator, which can typically something like invalid
+ format from openning up the .o files */
+ bfd_set_error (bfd_error_no_error);
+ lang_for_each_statement (build_link_order);
+
+ if (config.split_by_reloc || config.split_by_file)
+ split_sections (output_bfd, &link_info);
+ if (!bfd_final_link (output_bfd, &link_info))
+ {
+ /* If there was an error recorded, print it out. Otherwise assume
+ an appropriate error message like unknown symbol was printed
+ out. */
+
+ if (bfd_get_error () != bfd_error_no_error)
+ einfo (_("%F%P: final link failed: %E\n"), output_bfd);
+ else
+ xexit(1);
+ }
+}