xref: /netbsd-src/external/gpl3/binutils.old/dist/ld/emultempl/ppc32elf.em (revision 8ecbf5f02b752fcb7debe1a8fab1dc82602bc760)
1# This shell script emits a C file. -*- C -*-
2#   Copyright (C) 2003-2018 Free Software Foundation, Inc.
3#
4# This file is part of the GNU Binutils.
5#
6# This program is free software; you can redistribute it and/or modify
7# it under the terms of the GNU General Public License as published by
8# the Free Software Foundation; either version 3 of the License, or
9# (at your option) any later version.
10#
11# This program is distributed in the hope that it will be useful,
12# but WITHOUT ANY WARRANTY; without even the implied warranty of
13# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14# GNU General Public License for more details.
15#
16# You should have received a copy of the GNU General Public License
17# along with this program; if not, write to the Free Software
18# Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
19# MA 02110-1301, USA.
20#
21
22# This file is sourced from elf32.em, and defines extra powerpc32-elf
23# specific routines.
24#
25fragment <<EOF
26
27#include "elf32-ppc.h"
28#include "ldlex.h"
29#include "ldlang.h"
30
31#define is_ppc_elf(bfd) \
32  (bfd_get_flavour (bfd) == bfd_target_elf_flavour \
33   && elf_object_id (bfd) == PPC32_ELF_DATA)
34
35/* Whether to run tls optimization.  */
36static int notlsopt = 0;
37
38/* Whether to convert inline PLT calls to direct.  */
39static int no_inline_opt = 0;
40
41/* Choose the correct place for .got.  */
42static int old_got = 0;
43
44static struct ppc_elf_params params = { PLT_UNSET, 0, -1,
45					0, 0, 0, 0, 0, 0, 0 };
46
47static void
48ppc_after_open_output (void)
49{
50  if (params.emit_stub_syms < 0)
51    params.emit_stub_syms = (link_info.emitrelocations
52			     || bfd_link_pic (&link_info));
53  if (params.pagesize == 0)
54    params.pagesize = config.commonpagesize;
55  ppc_elf_link_params (&link_info, &params);
56}
57
58EOF
59
60# No --secure-plt, --bss-plt, or --sdata-got for vxworks.
61if test -z "$VXWORKS_BASE_EM_FILE" ; then
62  fragment <<EOF
63static void
64ppc_after_check_relocs (void)
65{
66  if (is_ppc_elf (link_info.output_bfd))
67    {
68      int new_plt;
69      int keep_new;
70      unsigned int num_plt;
71      unsigned int num_got;
72      lang_output_section_statement_type *os;
73      lang_output_section_statement_type *plt_os[2];
74      lang_output_section_statement_type *got_os[2];
75
76      new_plt = ppc_elf_select_plt_layout (link_info.output_bfd, &link_info);
77      if (new_plt < 0)
78	einfo (_("%X%P: select_plt_layout problem %E\n"));
79
80      num_got = 0;
81      num_plt = 0;
82      for (os = &lang_output_section_statement.head->output_section_statement;
83	   os != NULL;
84	   os = os->next)
85	{
86	  if (os->constraint == SPECIAL && strcmp (os->name, ".plt") == 0)
87	    {
88	      if (num_plt < 2)
89		plt_os[num_plt] = os;
90	      ++num_plt;
91	    }
92	  if (os->constraint == SPECIAL && strcmp (os->name, ".got") == 0)
93	    {
94	      if (num_got < 2)
95		got_os[num_got] = os;
96	      ++num_got;
97	    }
98	}
99
100      keep_new = new_plt == 1 ? 0 : -1;
101      if (num_plt == 2)
102	{
103	  plt_os[0]->constraint = keep_new;
104	  plt_os[1]->constraint = ~keep_new;
105	}
106      if (num_got == 2)
107	{
108	  if (old_got)
109	    keep_new = -1;
110	  got_os[0]->constraint = keep_new;
111	  got_os[1]->constraint = ~keep_new;
112	}
113    }
114
115  after_check_relocs_default ();
116}
117
118EOF
119fi
120fragment <<EOF
121static void
122prelim_size_sections (void)
123{
124  if (expld.phase != lang_mark_phase_enum)
125    {
126      expld.phase = lang_mark_phase_enum;
127      expld.dataseg.phase = exp_seg_none;
128      one_lang_size_sections_pass (NULL, FALSE);
129      /* We must not cache anything from the preliminary sizing.  */
130      lang_reset_memory_regions ();
131    }
132}
133
134static void
135ppc_before_allocation (void)
136{
137  if (is_ppc_elf (link_info.output_bfd))
138    {
139      if (!no_inline_opt
140	  && !bfd_link_relocatable (&link_info))
141	{
142	  prelim_size_sections ();
143
144	  if (!ppc_elf_inline_plt (&link_info))
145	    einfo (_("%X%P: inline PLT: %E\n"));
146	}
147
148      if (ppc_elf_tls_setup (link_info.output_bfd, &link_info)
149	  && !notlsopt)
150	{
151	  if (!ppc_elf_tls_optimize (link_info.output_bfd, &link_info))
152	    {
153	      einfo (_("%X%P: TLS problem %E\n"));
154	      return;
155	    }
156	}
157    }
158
159  gld${EMULATION_NAME}_before_allocation ();
160
161  ppc_elf_maybe_strip_sdata_syms (&link_info);
162
163  if (RELAXATION_ENABLED)
164    params.branch_trampolines = 1;
165
166  /* Turn on relaxation if executable sections have addresses that
167     might make branches overflow.  */
168  else if (!RELAXATION_DISABLED_BY_USER)
169    {
170      bfd_vma low = (bfd_vma) -1;
171      bfd_vma high = 0;
172      asection *o;
173
174      /* Run lang_size_sections (if not already done).  */
175      prelim_size_sections ();
176
177      for (o = link_info.output_bfd->sections; o != NULL; o = o->next)
178	{
179	  if ((o->flags & (SEC_ALLOC | SEC_CODE)) != (SEC_ALLOC | SEC_CODE))
180	    continue;
181	  if (o->rawsize == 0)
182	    continue;
183	  if (low > o->vma)
184	    low = o->vma;
185	  if (high < o->vma + o->rawsize - 1)
186	    high = o->vma + o->rawsize - 1;
187	}
188      if (high > low && high - low > (1 << 25) - 1)
189	params.branch_trampolines = 1;
190    }
191
192  if (params.branch_trampolines
193      || params.ppc476_workaround
194      || params.pic_fixup > 0)
195    ENABLE_RELAXATION;
196}
197
198/* Replaces default zero fill padding in executable sections with
199   "ba 0" instructions.  This works around the ppc476 icache bug if we
200   have a function pointer tail call near the end of a page, some
201   small amount of padding, then the function called at the beginning
202   of the next page.  If the "ba 0" is ever executed we should hit a
203   segv, so it's almost as good as an illegal instruction (zero).  */
204
205static void
206no_zero_padding (lang_statement_union_type *l)
207{
208  if (l->header.type == lang_padding_statement_enum
209      && l->padding_statement.size != 0
210      && l->padding_statement.output_section != NULL
211      && (l->padding_statement.output_section->flags & SEC_CODE) != 0
212      && l->padding_statement.fill->size == 0)
213    {
214      struct _ppc_fill_type
215      {
216	size_t size;
217	unsigned char data[4];
218      };
219      static struct _ppc_fill_type fill_be = { 4, {0x48, 0, 0, 2} };
220      static struct _ppc_fill_type fill_le = { 4, {2, 0, 0, 0x48} };
221
222      if (bfd_big_endian (link_info.output_bfd))
223	l->padding_statement.fill = (struct _fill_type *) &fill_be;
224      else
225	l->padding_statement.fill = (struct _fill_type *) &fill_le;
226    }
227}
228
229static void
230ppc_finish (void)
231{
232  if (params.ppc476_workaround)
233    lang_for_each_statement (no_zero_padding);
234  if (!ppc_finish_symbols (&link_info))
235    einfo (_("%X%P: ppc_finish_symbols problem %E\n"));
236  finish_default ();
237}
238
239EOF
240
241if grep -q 'ld_elf32_spu_emulation' ldemul-list.h; then
242  fragment <<EOF
243/* Special handling for embedded SPU executables.  */
244extern bfd_boolean embedded_spu_file (lang_input_statement_type *, const char *);
245static bfd_boolean gld${EMULATION_NAME}_load_symbols (lang_input_statement_type *);
246
247static bfd_boolean
248ppc_recognized_file (lang_input_statement_type *entry)
249{
250  if (embedded_spu_file (entry, "-m32"))
251    return TRUE;
252
253  return gld${EMULATION_NAME}_load_symbols (entry);
254}
255
256EOF
257LDEMUL_RECOGNIZED_FILE=ppc_recognized_file
258fi
259
260# Define some shell vars to insert bits of code into the standard elf
261# parse_args and list_options functions.
262#
263PARSE_AND_LIST_PROLOGUE=${PARSE_AND_LIST_PROLOGUE}'
264enum ppc32_opt
265{
266  OPTION_NO_TLS_OPT = 321,
267  OPTION_NO_TLS_GET_ADDR_OPT,
268  OPTION_NEW_PLT,
269  OPTION_OLD_PLT,
270  OPTION_PLT_ALIGN,
271  OPTION_NO_PLT_ALIGN,
272  OPTION_NO_INLINE_OPT,
273  OPTION_OLD_GOT,
274  OPTION_STUBSYMS,
275  OPTION_NO_STUBSYMS,
276  OPTION_PPC476_WORKAROUND,
277  OPTION_NO_PPC476_WORKAROUND,
278  OPTION_NO_PICFIXUP,
279  OPTION_VLE_RELOC_FIXUP
280};
281'
282
283PARSE_AND_LIST_LONGOPTS=${PARSE_AND_LIST_LONGOPTS}'
284  { "emit-stub-syms", no_argument, NULL, OPTION_STUBSYMS },
285  { "no-emit-stub-syms", no_argument, NULL, OPTION_NO_STUBSYMS },
286  { "no-tls-optimize", no_argument, NULL, OPTION_NO_TLS_OPT },
287  { "no-tls-get-addr-optimize", no_argument, NULL, OPTION_NO_TLS_GET_ADDR_OPT },'
288if test -z "$VXWORKS_BASE_EM_FILE" ; then
289  PARSE_AND_LIST_LONGOPTS=${PARSE_AND_LIST_LONGOPTS}'
290  { "secure-plt", no_argument, NULL, OPTION_NEW_PLT },
291  { "bss-plt", no_argument, NULL, OPTION_OLD_PLT },
292  { "plt-align", optional_argument, NULL, OPTION_PLT_ALIGN },
293  { "no-plt-align", no_argument, NULL, OPTION_NO_PLT_ALIGN },
294  { "no-inline-optimize", no_argument, NULL, OPTION_NO_INLINE_OPT },
295  { "sdata-got", no_argument, NULL, OPTION_OLD_GOT },'
296fi
297PARSE_AND_LIST_LONGOPTS=${PARSE_AND_LIST_LONGOPTS}'
298  { "ppc476-workaround", optional_argument, NULL, OPTION_PPC476_WORKAROUND },
299  { "no-ppc476-workaround", no_argument, NULL, OPTION_NO_PPC476_WORKAROUND },
300  { "no-pic-fixup", no_argument, NULL, OPTION_NO_PICFIXUP },
301  { "vle-reloc-fixup", no_argument, NULL, OPTION_VLE_RELOC_FIXUP },
302'
303
304PARSE_AND_LIST_OPTIONS=${PARSE_AND_LIST_OPTIONS}'
305  fprintf (file, _("\
306  --emit-stub-syms            Label linker stubs with a symbol\n"
307		   ));
308  fprintf (file, _("\
309  --no-emit-stub-syms         Don'\''t label linker stubs with a symbol\n"
310		   ));
311  fprintf (file, _("\
312  --no-tls-optimize           Don'\''t try to optimize TLS accesses\n"
313		   ));
314  fprintf (file, _("\
315  --no-tls-get-addr-optimize  Don'\''t use a special __tls_get_addr call\n"
316		   ));'
317if test -z "$VXWORKS_BASE_EM_FILE" ; then
318  PARSE_AND_LIST_OPTIONS=${PARSE_AND_LIST_OPTIONS}'\
319  fprintf (file, _("\
320  --secure-plt                Use new-style PLT if possible\n"
321		   ));
322  fprintf (file, _("\
323  --bss-plt                   Force old-style BSS PLT\n"
324		   ));
325  fprintf (file, _("\
326  --plt-align                 Align PLT call stubs to fit cache lines\n"
327		   ));
328  fprintf (file, _("\
329  --no-plt-align              Dont'\''t align individual PLT call stubs\n"
330		   ));
331  fprintf (file, _("\
332  --no-inline-optimize        Don'\''t convert inline PLT to direct calls\n"
333		   ));
334  fprintf (file, _("\
335  --sdata-got                 Force GOT location just before .sdata\n"
336		   ));'
337fi
338PARSE_AND_LIST_OPTIONS=${PARSE_AND_LIST_OPTIONS}'\
339  fprintf (file, _("\
340  --ppc476-workaround [=pagesize]\n\
341                              Avoid a cache bug on ppc476\n"
342		   ));
343  fprintf (file, _("\
344  --no-ppc476-workaround      Disable workaround\n"
345		   ));
346  fprintf (file, _("\
347  --no-pic-fixup              Don'\''t edit non-pic to pic\n"
348		   ));
349  fprintf (file, _("\
350  --vle-reloc-fixup           Correct old object file 16A/16D relocation\n"
351		   ));
352'
353
354PARSE_AND_LIST_ARGS_CASES=${PARSE_AND_LIST_ARGS_CASES}'
355    case OPTION_STUBSYMS:
356      params.emit_stub_syms = 1;
357      break;
358
359    case OPTION_NO_STUBSYMS:
360      params.emit_stub_syms = 0;
361      break;
362
363    case OPTION_NO_TLS_OPT:
364      notlsopt = 1;
365      break;
366
367    case OPTION_NO_TLS_GET_ADDR_OPT:
368      params.no_tls_get_addr_opt = 1;
369      break;
370
371    case OPTION_NEW_PLT:
372      params.plt_style = PLT_NEW;
373      break;
374
375    case OPTION_OLD_PLT:
376      params.plt_style = PLT_OLD;
377      break;
378
379    case OPTION_PLT_ALIGN:
380      if (optarg != NULL)
381	{
382	  char *end;
383	  unsigned long val = strtoul (optarg, &end, 0);
384	  if (*end || val > 5)
385	    einfo (_("%F%P: invalid --plt-align `%s'\''\n"), optarg);
386	  params.plt_stub_align = val;
387	}
388      else
389	params.plt_stub_align = 5;
390      break;
391
392    case OPTION_NO_PLT_ALIGN:
393      params.plt_stub_align = 0;
394      break;
395
396    case OPTION_NO_INLINE_OPT:
397      no_inline_opt = 1;
398      break;
399
400    case OPTION_OLD_GOT:
401      old_got = 1;
402      break;
403
404    case OPTION_TRADITIONAL_FORMAT:
405      notlsopt = 1;
406      params.no_tls_get_addr_opt = 1;
407      return FALSE;
408
409    case OPTION_PPC476_WORKAROUND:
410      params.ppc476_workaround = 1;
411      if (optarg != NULL)
412	{
413	  char *end;
414	  params.pagesize = strtoul (optarg, &end, 0);
415	  if (*end
416	      || (params.pagesize < 4096 && params.pagesize != 0)
417	      || params.pagesize != (params.pagesize & -params.pagesize))
418	    einfo (_("%F%P: invalid pagesize `%s'\''\n"), optarg);
419	}
420      break;
421
422    case OPTION_NO_PPC476_WORKAROUND:
423      params.ppc476_workaround = 0;
424      break;
425
426    case OPTION_NO_PICFIXUP:
427      params.pic_fixup = -1;
428      break;
429
430    case OPTION_VLE_RELOC_FIXUP:
431      params.vle_reloc_fixup = 1;
432      break;
433'
434
435# Put these extra ppc32elf routines in ld_${EMULATION_NAME}_emulation
436#
437LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=ppc_after_open_output
438if test -z "$VXWORKS_BASE_EM_FILE" ; then
439  LDEMUL_AFTER_CHECK_RELOCS=ppc_after_check_relocs
440fi
441LDEMUL_BEFORE_ALLOCATION=ppc_before_allocation
442LDEMUL_FINISH=ppc_finish
443