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authorRichard Sandiford <rdsandiford@googlemail.com>2009-03-14 09:18:22 +0000
committerRichard Sandiford <rdsandiford@googlemail.com>2009-03-14 09:18:22 +0000
commit47dfb2ca058b165e333767f15a62c603830284dd (patch)
treea63bf6d8dcb639614b5a97e3471810ff6257b705 /bfd/xcofflink.c
parent4cc02a022b59a6f9c6041c7ac993157db0fdd1dc (diff)
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bfd/
* xcofflink.c: (xcoff_mark_symbol): Mark the TOC section when creating a descriptor. (xcoff_sweep): Don't mark toc_section unless it's needed. (bfd_xcoff_size_dynamic_sections): Skip the toc_section when marking every bfd. (xcoff_link_input_bfd): Skip all TOC anchors. (xcoff_toc_section_p, xcoff_find_tc0): New functions. (_bfd_xcoff_bfd_final_link): Don't set the output bfd's TOC anchor to -1; call xcoff_find_tc0 instead. ld/testsuite/ * ld-powerpc/aix-toc-1.ex, ld-powerpc/aix-toc-1a.s, ld-powerpc/aix-toc-1b.s, ld-powerpc/aix-toc-1-32.dd, ld-powerpc/aix-toc-1-64.dd: New tests. * ld-powerpc/aix52.exp: Run them.
Diffstat (limited to 'bfd/xcofflink.c')
-rw-r--r--bfd/xcofflink.c232
1 files changed, 155 insertions, 77 deletions
diff --git a/bfd/xcofflink.c b/bfd/xcofflink.c
index d12ed51..c6bdc9f 100644
--- a/bfd/xcofflink.c
+++ b/bfd/xcofflink.c
@@ -2331,6 +2331,11 @@ xcoff_mark_symbol (struct bfd_link_info *info, struct xcoff_link_hash_entry *h)
if (!xcoff_mark_symbol (info, h->descriptor))
return FALSE;
+ /* Mark the TOC section, so that we get an anchor
+ to relocate against. */
+ if (!xcoff_mark (info, xcoff_hash_table (info)->toc_section))
+ return FALSE;
+
/* We handle writing out the contents of the descriptor in
xcoff_write_global_symbol. */
}
@@ -2590,7 +2595,6 @@ xcoff_sweep (struct bfd_link_info *info)
|| o == xcoff_hash_table (info)->debug_section
|| 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;
@@ -3126,7 +3130,12 @@ bfd_xcoff_size_dynamic_sections (bfd *output_bfd,
for (o = sub->sections; o != NULL; o = o->next)
{
- if ((o->flags & SEC_MARK) == 0)
+ /* We shouldn't unconditionaly mark the TOC section.
+ The output file should only have a TOC if either
+ (a) one of the input files did or (b) we end up
+ creating TOC references as part of the link process. */
+ if (o != xcoff_hash_table (info)->toc_section
+ && (o->flags & SEC_MARK) == 0)
{
if (! xcoff_mark (info, o))
goto error_return;
@@ -3504,7 +3513,6 @@ xcoff_link_input_bfd (struct xcoff_final_link_info *finfo,
union internal_auxent aux;
int smtyp = 0;
bfd_boolean skip;
- bfd_boolean require;
int add;
bfd_coff_swap_sym_in (input_bfd, (void *) esym, (void *) isymp);
@@ -3623,7 +3631,6 @@ xcoff_link_input_bfd (struct xcoff_final_link_info *finfo,
*indexp = -1;
skip = FALSE;
- require = FALSE;
add = 1 + isym.n_numaux;
/* If we are skipping this csect, we want to skip this symbol. */
@@ -3644,75 +3651,11 @@ xcoff_link_input_bfd (struct xcoff_final_link_info *finfo,
&& isymp->n_sclass == C_STAT)
skip = TRUE;
- /* We skip all but the first TOC anchor. */
+ /* We generate the TOC anchor separately. */
if (! skip
&& isymp->n_sclass == C_HIDEXT
&& aux.x_csect.x_smclas == XMC_TC0)
- {
- if (finfo->toc_symindx != -1)
- skip = TRUE;
- else
- {
- bfd_vma tocval, tocend;
- bfd *inp;
-
- tocval = ((*csectpp)->output_section->vma
- + (*csectpp)->output_offset
- + isym.n_value
- - (*csectpp)->vma);
-
- /* We want to find out if tocval is a good value to use
- as the TOC anchor--that is, whether we can access all
- of the TOC using a 16 bit offset from tocval. This
- test assumes that the TOC comes at the end of the
- output section, as it does in the default linker
- script. */
- tocend = ((*csectpp)->output_section->vma
- + (*csectpp)->output_section->size);
- for (inp = finfo->info->input_bfds;
- inp != NULL;
- inp = inp->link_next)
- {
-
- for (o = inp->sections; o != NULL; o = o->next)
- if (strcmp (o->name, ".tocbss") == 0)
- {
- bfd_vma new_toc_end;
- new_toc_end = (o->output_section->vma
- + o->output_offset
- + o->size);
- if (new_toc_end > tocend)
- tocend = new_toc_end;
- }
-
- }
-
- if (tocval + 0x10000 < tocend)
- {
- (*_bfd_error_handler)
- (_("TOC overflow: 0x%lx > 0x10000; try -mminimal-toc when compiling"),
- (unsigned long) (tocend - tocval));
- bfd_set_error (bfd_error_file_too_big);
- return FALSE;
- }
-
- if (tocval + 0x8000 < tocend)
- {
- bfd_vma tocadd;
-
- tocadd = tocend - (tocval + 0x8000);
- tocval += tocadd;
- isym.n_value += tocadd;
- }
-
- finfo->toc_symindx = output_index;
- xcoff_data (finfo->output_bfd)->toc = tocval;
- xcoff_data (finfo->output_bfd)->sntoc =
- (*csectpp)->output_section->target_index;
- require = TRUE;
-
- }
- }
+ skip = TRUE;
/* If we are stripping all symbols, we want to skip this one. */
if (! skip
@@ -3781,12 +3724,6 @@ xcoff_link_input_bfd (struct xcoff_final_link_info *finfo,
skip = TRUE;
}
- /* We can not skip the first TOC anchor. */
- if (skip
- && require
- && finfo->info->strip != strip_all)
- skip = FALSE;
-
/* We now know whether we are to skip this symbol or not. */
if (! skip)
{
@@ -4616,6 +4553,144 @@ xcoff_sort_relocs (const void * p1, const void * p2)
return 0;
}
+/* Return true if section SEC is a TOC section. */
+
+static inline bfd_boolean
+xcoff_toc_section_p (asection *sec)
+{
+ const char *name;
+
+ name = sec->name;
+ if (name[0] == '.' && name[1] == 't')
+ {
+ if (name[2] == 'c')
+ {
+ if (name[3] == '0' && name[4] == 0)
+ return TRUE;
+ if (name[3] == 0)
+ return TRUE;
+ }
+ if (name[2] == 'd' && name[3] == 0)
+ return TRUE;
+ }
+ return FALSE;
+}
+
+/* See if the link requires a TOC (it usually does!). If so, find a
+ good place to put the TOC anchor csect, and write out the associated
+ symbol. */
+
+static bfd_boolean
+xcoff_find_tc0 (bfd *output_bfd, struct xcoff_final_link_info *finfo)
+{
+ bfd_vma toc_start, toc_end, start, end, best_address;
+ asection *sec;
+ bfd *input_bfd;
+ int section_index;
+ struct internal_syment irsym;
+ union internal_auxent iraux;
+ file_ptr pos;
+ size_t size;
+
+ /* Set [TOC_START, TOC_END) to the range of the TOC. Record the
+ index of a csect at the beginning of the TOC. */
+ toc_start = ~(bfd_vma) 0;
+ toc_end = 0;
+ section_index = -1;
+ for (input_bfd = finfo->info->input_bfds;
+ input_bfd != NULL;
+ input_bfd = input_bfd->link_next)
+ for (sec = input_bfd->sections; sec != NULL; sec = sec->next)
+ if ((sec->flags & SEC_MARK) != 0 && xcoff_toc_section_p (sec))
+ {
+ start = sec->output_section->vma + sec->output_offset;
+ if (toc_start > start)
+ {
+ toc_start = start;
+ section_index = sec->output_section->target_index;
+ }
+
+ end = start + sec->size;
+ if (toc_end < end)
+ toc_end = end;
+ }
+
+ /* There's no need for a TC0 symbol if we don't have a TOC. */
+ if (toc_end < toc_start)
+ {
+ xcoff_data (output_bfd)->toc = toc_start;
+ return TRUE;
+ }
+
+ if (toc_end - toc_start < 0x8000)
+ /* Every TOC csect can be accessed from TOC_START. */
+ best_address = toc_start;
+ else
+ {
+ /* Find the lowest TOC csect that is still within range of TOC_END. */
+ best_address = toc_end;
+ for (input_bfd = finfo->info->input_bfds;
+ input_bfd != NULL;
+ input_bfd = input_bfd->link_next)
+ for (sec = input_bfd->sections; sec != NULL; sec = sec->next)
+ if ((sec->flags & SEC_MARK) != 0 && xcoff_toc_section_p (sec))
+ {
+ start = sec->output_section->vma + sec->output_offset;
+ if (start < best_address
+ && start + 0x8000 >= toc_end)
+ {
+ best_address = start;
+ section_index = sec->output_section->target_index;
+ }
+ }
+
+ /* Make sure that the start of the TOC is also within range. */
+ if (best_address > toc_start + 0x8000)
+ {
+ (*_bfd_error_handler)
+ (_("TOC overflow: 0x%lx > 0x10000; try -mminimal-toc "
+ "when compiling"),
+ (unsigned long) (toc_end - toc_start));
+ bfd_set_error (bfd_error_file_too_big);
+ return FALSE;
+ }
+ }
+
+ /* Record the chosen TOC value. */
+ finfo->toc_symindx = obj_raw_syment_count (output_bfd);
+ xcoff_data (output_bfd)->toc = best_address;
+ xcoff_data (output_bfd)->sntoc = section_index;
+
+ /* Fill out the TC0 symbol. */
+ if (!bfd_xcoff_put_symbol_name (output_bfd, finfo->strtab, &irsym, "TOC"))
+ return FALSE;
+ irsym.n_value = best_address;
+ irsym.n_scnum = section_index;
+ irsym.n_sclass = C_HIDEXT;
+ irsym.n_type = T_NULL;
+ irsym.n_numaux = 1;
+ bfd_coff_swap_sym_out (output_bfd, &irsym, finfo->outsyms);
+
+ /* Fill out the auxillary csect information. */
+ memset (&iraux, 0, sizeof iraux);
+ iraux.x_csect.x_smtyp = XTY_SD;
+ iraux.x_csect.x_smclas = XMC_TC0;
+ iraux.x_csect.x_scnlen.l = 0;
+ bfd_coff_swap_aux_out (output_bfd, &iraux, T_NULL, C_HIDEXT, 0, 1,
+ finfo->outsyms + bfd_coff_symesz (output_bfd));
+
+ /* Write the contents to the file. */
+ pos = obj_sym_filepos (output_bfd);
+ pos += obj_raw_syment_count (output_bfd) * bfd_coff_symesz (output_bfd);
+ size = 2 * bfd_coff_symesz (output_bfd);
+ if (bfd_seek (output_bfd, pos, SEEK_SET) != 0
+ || bfd_bwrite (finfo->outsyms, size, output_bfd) != size)
+ return FALSE;
+ obj_raw_syment_count (output_bfd) += 2;
+
+ return TRUE;
+}
+
/* Write out a non-XCOFF global symbol. */
static bfd_boolean
@@ -5692,7 +5767,10 @@ _bfd_xcoff_bfd_final_link (bfd *abfd, struct bfd_link_info *info)
goto error_return;
obj_raw_syment_count (abfd) = 0;
- xcoff_data (abfd)->toc = (bfd_vma) -1;
+
+ /* Find a TOC symbol, if we need one. */
+ if (!xcoff_find_tc0 (abfd, &finfo))
+ goto error_return;
/* We now know the position of everything in the file, except that
we don't know the size of the symbol table and therefore we don't