* output.h (Output_section_lookup_maps::add_merge_section):
[external/binutils.git] / gold / i386.cc
1 // i386.cc -- i386 target support for gold.
2
3 // Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
5
6 // This file is part of gold.
7
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
12
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 // GNU General Public License for more details.
17
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
22
23 #include "gold.h"
24
25 #include <cstring>
26
27 #include "elfcpp.h"
28 #include "parameters.h"
29 #include "reloc.h"
30 #include "i386.h"
31 #include "object.h"
32 #include "symtab.h"
33 #include "layout.h"
34 #include "output.h"
35 #include "copy-relocs.h"
36 #include "target.h"
37 #include "target-reloc.h"
38 #include "target-select.h"
39 #include "tls.h"
40 #include "freebsd.h"
41 #include "gc.h"
42
43 namespace
44 {
45
46 using namespace gold;
47
48 class Output_data_plt_i386;
49
50 // The i386 target class.
51 // TLS info comes from
52 //   http://people.redhat.com/drepper/tls.pdf
53 //   http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
54
55 class Target_i386 : public Target_freebsd<32, false>
56 {
57  public:
58   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
59
60   Target_i386()
61     : Target_freebsd<32, false>(&i386_info),
62       got_(NULL), plt_(NULL), got_plt_(NULL), global_offset_table_(NULL),
63       rel_dyn_(NULL), copy_relocs_(elfcpp::R_386_COPY), dynbss_(NULL),
64       got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
65   { }
66
67   inline bool
68   can_check_for_function_pointers() const
69   { return true; }
70
71   // Process the relocations to determine unreferenced sections for 
72   // garbage collection.
73   void
74   gc_process_relocs(Symbol_table* symtab,
75                     Layout* layout,
76                     Sized_relobj<32, false>* object,
77                     unsigned int data_shndx,
78                     unsigned int sh_type,
79                     const unsigned char* prelocs,
80                     size_t reloc_count,
81                     Output_section* output_section,
82                     bool needs_special_offset_handling,
83                     size_t local_symbol_count,
84                     const unsigned char* plocal_symbols);
85
86   // Scan the relocations to look for symbol adjustments.
87   void
88   scan_relocs(Symbol_table* symtab,
89               Layout* layout,
90               Sized_relobj<32, false>* object,
91               unsigned int data_shndx,
92               unsigned int sh_type,
93               const unsigned char* prelocs,
94               size_t reloc_count,
95               Output_section* output_section,
96               bool needs_special_offset_handling,
97               size_t local_symbol_count,
98               const unsigned char* plocal_symbols);
99
100   // Finalize the sections.
101   void
102   do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
103
104   // Return the value to use for a dynamic which requires special
105   // treatment.
106   uint64_t
107   do_dynsym_value(const Symbol*) const;
108
109   // Relocate a section.
110   void
111   relocate_section(const Relocate_info<32, false>*,
112                    unsigned int sh_type,
113                    const unsigned char* prelocs,
114                    size_t reloc_count,
115                    Output_section* output_section,
116                    bool needs_special_offset_handling,
117                    unsigned char* view,
118                    elfcpp::Elf_types<32>::Elf_Addr view_address,
119                    section_size_type view_size,
120                    const Reloc_symbol_changes*);
121
122   // Scan the relocs during a relocatable link.
123   void
124   scan_relocatable_relocs(Symbol_table* symtab,
125                           Layout* layout,
126                           Sized_relobj<32, false>* object,
127                           unsigned int data_shndx,
128                           unsigned int sh_type,
129                           const unsigned char* prelocs,
130                           size_t reloc_count,
131                           Output_section* output_section,
132                           bool needs_special_offset_handling,
133                           size_t local_symbol_count,
134                           const unsigned char* plocal_symbols,
135                           Relocatable_relocs*);
136
137   // Relocate a section during a relocatable link.
138   void
139   relocate_for_relocatable(const Relocate_info<32, false>*,
140                            unsigned int sh_type,
141                            const unsigned char* prelocs,
142                            size_t reloc_count,
143                            Output_section* output_section,
144                            off_t offset_in_output_section,
145                            const Relocatable_relocs*,
146                            unsigned char* view,
147                            elfcpp::Elf_types<32>::Elf_Addr view_address,
148                            section_size_type view_size,
149                            unsigned char* reloc_view,
150                            section_size_type reloc_view_size);
151
152   // Return a string used to fill a code section with nops.
153   std::string
154   do_code_fill(section_size_type length) const;
155
156   // Return whether SYM is defined by the ABI.
157   bool
158   do_is_defined_by_abi(const Symbol* sym) const
159   { return strcmp(sym->name(), "___tls_get_addr") == 0; }
160
161   // Return whether a symbol name implies a local label.  The UnixWare
162   // 2.1 cc generates temporary symbols that start with .X, so we
163   // recognize them here.  FIXME: do other SVR4 compilers also use .X?.
164   // If so, we should move the .X recognition into
165   // Target::do_is_local_label_name.
166   bool
167   do_is_local_label_name(const char* name) const
168   {
169     if (name[0] == '.' && name[1] == 'X')
170       return true;
171     return Target::do_is_local_label_name(name);
172   }
173
174   // Return whether SYM is call to a non-split function.
175   bool
176   do_is_call_to_non_split(const Symbol* sym, unsigned int) const;
177
178   // Adjust -fstack-split code which calls non-stack-split code.
179   void
180   do_calls_non_split(Relobj* object, unsigned int shndx,
181                      section_offset_type fnoffset, section_size_type fnsize,
182                      unsigned char* view, section_size_type view_size,
183                      std::string* from, std::string* to) const;
184
185   // Return the size of the GOT section.
186   section_size_type
187   got_size()
188   {
189     gold_assert(this->got_ != NULL);
190     return this->got_->data_size();
191   }
192
193  private:
194   // The class which scans relocations.
195   struct Scan
196   {
197     inline void
198     local(Symbol_table* symtab, Layout* layout, Target_i386* target,
199           Sized_relobj<32, false>* object,
200           unsigned int data_shndx,
201           Output_section* output_section,
202           const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
203           const elfcpp::Sym<32, false>& lsym);
204
205     inline void
206     global(Symbol_table* symtab, Layout* layout, Target_i386* target,
207            Sized_relobj<32, false>* object,
208            unsigned int data_shndx,
209            Output_section* output_section,
210            const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
211            Symbol* gsym);
212
213     inline bool
214     local_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
215                                         Target_i386* target,
216                                         Sized_relobj<32, false>* object,
217                                         unsigned int data_shndx,
218                                         Output_section* output_section,
219                                         const elfcpp::Rel<32, false>& reloc,
220                                         unsigned int r_type,
221                                         const elfcpp::Sym<32, false>& lsym);
222
223     inline bool
224     global_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
225                                          Target_i386* target,
226                                          Sized_relobj<32, false>* object,
227                                          unsigned int data_shndx,
228                                          Output_section* output_section,
229                                          const elfcpp::Rel<32, false>& reloc,
230                                          unsigned int r_type,
231                                          Symbol* gsym);
232
233     inline bool
234     possible_function_pointer_reloc(unsigned int r_type);
235
236     static void
237     unsupported_reloc_local(Sized_relobj<32, false>*, unsigned int r_type);
238
239     static void
240     unsupported_reloc_global(Sized_relobj<32, false>*, unsigned int r_type,
241                              Symbol*);
242   };
243
244   // The class which implements relocation.
245   class Relocate
246   {
247    public:
248     Relocate()
249       : skip_call_tls_get_addr_(false),
250         local_dynamic_type_(LOCAL_DYNAMIC_NONE)
251     { }
252
253     ~Relocate()
254     {
255       if (this->skip_call_tls_get_addr_)
256         {
257           // FIXME: This needs to specify the location somehow.
258           gold_error(_("missing expected TLS relocation"));
259         }
260     }
261
262     // Return whether the static relocation needs to be applied.
263     inline bool
264     should_apply_static_reloc(const Sized_symbol<32>* gsym,
265                               int ref_flags,
266                               bool is_32bit,
267                               Output_section* output_section);
268
269     // Do a relocation.  Return false if the caller should not issue
270     // any warnings about this relocation.
271     inline bool
272     relocate(const Relocate_info<32, false>*, Target_i386*, Output_section*,
273              size_t relnum, const elfcpp::Rel<32, false>&,
274              unsigned int r_type, const Sized_symbol<32>*,
275              const Symbol_value<32>*,
276              unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
277              section_size_type);
278
279    private:
280     // Do a TLS relocation.
281     inline void
282     relocate_tls(const Relocate_info<32, false>*, Target_i386* target,
283                  size_t relnum, const elfcpp::Rel<32, false>&,
284                  unsigned int r_type, const Sized_symbol<32>*,
285                  const Symbol_value<32>*,
286                  unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
287                  section_size_type);
288
289     // Do a TLS General-Dynamic to Initial-Exec transition.
290     inline void
291     tls_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
292                  Output_segment* tls_segment,
293                  const elfcpp::Rel<32, false>&, unsigned int r_type,
294                  elfcpp::Elf_types<32>::Elf_Addr value,
295                  unsigned char* view,
296                  section_size_type view_size);
297
298     // Do a TLS General-Dynamic to Local-Exec transition.
299     inline void
300     tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
301                  Output_segment* tls_segment,
302                  const elfcpp::Rel<32, false>&, unsigned int r_type,
303                  elfcpp::Elf_types<32>::Elf_Addr value,
304                  unsigned char* view,
305                  section_size_type view_size);
306
307     // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
308     // transition.
309     inline void
310     tls_desc_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
311                       Output_segment* tls_segment,
312                       const elfcpp::Rel<32, false>&, unsigned int r_type,
313                       elfcpp::Elf_types<32>::Elf_Addr value,
314                       unsigned char* view,
315                       section_size_type view_size);
316
317     // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
318     // transition.
319     inline void
320     tls_desc_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
321                       Output_segment* tls_segment,
322                       const elfcpp::Rel<32, false>&, unsigned int r_type,
323                       elfcpp::Elf_types<32>::Elf_Addr value,
324                       unsigned char* view,
325                       section_size_type view_size);
326
327     // Do a TLS Local-Dynamic to Local-Exec transition.
328     inline void
329     tls_ld_to_le(const Relocate_info<32, false>*, size_t relnum,
330                  Output_segment* tls_segment,
331                  const elfcpp::Rel<32, false>&, unsigned int r_type,
332                  elfcpp::Elf_types<32>::Elf_Addr value,
333                  unsigned char* view,
334                  section_size_type view_size);
335
336     // Do a TLS Initial-Exec to Local-Exec transition.
337     static inline void
338     tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum,
339                  Output_segment* tls_segment,
340                  const elfcpp::Rel<32, false>&, unsigned int r_type,
341                  elfcpp::Elf_types<32>::Elf_Addr value,
342                  unsigned char* view,
343                  section_size_type view_size);
344
345     // We need to keep track of which type of local dynamic relocation
346     // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
347     enum Local_dynamic_type
348     {
349       LOCAL_DYNAMIC_NONE,
350       LOCAL_DYNAMIC_SUN,
351       LOCAL_DYNAMIC_GNU
352     };
353
354     // This is set if we should skip the next reloc, which should be a
355     // PLT32 reloc against ___tls_get_addr.
356     bool skip_call_tls_get_addr_;
357     // The type of local dynamic relocation we have seen in the section
358     // being relocated, if any.
359     Local_dynamic_type local_dynamic_type_;
360   };
361
362   // A class which returns the size required for a relocation type,
363   // used while scanning relocs during a relocatable link.
364   class Relocatable_size_for_reloc
365   {
366    public:
367     unsigned int
368     get_size_for_reloc(unsigned int, Relobj*);
369   };
370
371   // Adjust TLS relocation type based on the options and whether this
372   // is a local symbol.
373   static tls::Tls_optimization
374   optimize_tls_reloc(bool is_final, int r_type);
375
376   // Get the GOT section, creating it if necessary.
377   Output_data_got<32, false>*
378   got_section(Symbol_table*, Layout*);
379
380   // Get the GOT PLT section.
381   Output_data_space*
382   got_plt_section() const
383   {
384     gold_assert(this->got_plt_ != NULL);
385     return this->got_plt_;
386   }
387
388   // Create a PLT entry for a global symbol.
389   void
390   make_plt_entry(Symbol_table*, Layout*, Symbol*);
391
392   // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
393   void
394   define_tls_base_symbol(Symbol_table*, Layout*);
395
396   // Create a GOT entry for the TLS module index.
397   unsigned int
398   got_mod_index_entry(Symbol_table* symtab, Layout* layout,
399                       Sized_relobj<32, false>* object);
400
401   // Get the PLT section.
402   Output_data_plt_i386*
403   plt_section() const
404   {
405     gold_assert(this->plt_ != NULL);
406     return this->plt_;
407   }
408
409   // Get the dynamic reloc section, creating it if necessary.
410   Reloc_section*
411   rel_dyn_section(Layout*);
412
413   // Get the section to use for TLS_DESC relocations.
414   Reloc_section*
415   rel_tls_desc_section(Layout*) const;
416
417   // Add a potential copy relocation.
418   void
419   copy_reloc(Symbol_table* symtab, Layout* layout,
420              Sized_relobj<32, false>* object,
421              unsigned int shndx, Output_section* output_section,
422              Symbol* sym, const elfcpp::Rel<32, false>& reloc)
423   {
424     this->copy_relocs_.copy_reloc(symtab, layout,
425                                   symtab->get_sized_symbol<32>(sym),
426                                   object, shndx, output_section, reloc,
427                                   this->rel_dyn_section(layout));
428   }
429
430   // Information about this specific target which we pass to the
431   // general Target structure.
432   static const Target::Target_info i386_info;
433
434   // The types of GOT entries needed for this platform.
435   enum Got_type
436   {
437     GOT_TYPE_STANDARD = 0,      // GOT entry for a regular symbol
438     GOT_TYPE_TLS_NOFFSET = 1,   // GOT entry for negative TLS offset
439     GOT_TYPE_TLS_OFFSET = 2,    // GOT entry for positive TLS offset
440     GOT_TYPE_TLS_PAIR = 3,      // GOT entry for TLS module/offset pair
441     GOT_TYPE_TLS_DESC = 4       // GOT entry for TLS_DESC pair
442   };
443
444   // The GOT section.
445   Output_data_got<32, false>* got_;
446   // The PLT section.
447   Output_data_plt_i386* plt_;
448   // The GOT PLT section.
449   Output_data_space* got_plt_;
450   // The _GLOBAL_OFFSET_TABLE_ symbol.
451   Symbol* global_offset_table_;
452   // The dynamic reloc section.
453   Reloc_section* rel_dyn_;
454   // Relocs saved to avoid a COPY reloc.
455   Copy_relocs<elfcpp::SHT_REL, 32, false> copy_relocs_;
456   // Space for variables copied with a COPY reloc.
457   Output_data_space* dynbss_;
458   // Offset of the GOT entry for the TLS module index.
459   unsigned int got_mod_index_offset_;
460   // True if the _TLS_MODULE_BASE_ symbol has been defined.
461   bool tls_base_symbol_defined_;
462 };
463
464 const Target::Target_info Target_i386::i386_info =
465 {
466   32,                   // size
467   false,                // is_big_endian
468   elfcpp::EM_386,       // machine_code
469   false,                // has_make_symbol
470   false,                // has_resolve
471   true,                 // has_code_fill
472   true,                 // is_default_stack_executable
473   '\0',                 // wrap_char
474   "/usr/lib/libc.so.1", // dynamic_linker
475   0x08048000,           // default_text_segment_address
476   0x1000,               // abi_pagesize (overridable by -z max-page-size)
477   0x1000,               // common_pagesize (overridable by -z common-page-size)
478   elfcpp::SHN_UNDEF,    // small_common_shndx
479   elfcpp::SHN_UNDEF,    // large_common_shndx
480   0,                    // small_common_section_flags
481   0,                    // large_common_section_flags
482   NULL,                 // attributes_section
483   NULL                  // attributes_vendor
484 };
485
486 // Get the GOT section, creating it if necessary.
487
488 Output_data_got<32, false>*
489 Target_i386::got_section(Symbol_table* symtab, Layout* layout)
490 {
491   if (this->got_ == NULL)
492     {
493       gold_assert(symtab != NULL && layout != NULL);
494
495       this->got_ = new Output_data_got<32, false>();
496
497       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
498                                       (elfcpp::SHF_ALLOC
499                                        | elfcpp::SHF_WRITE),
500                                       this->got_, false, true, true, false);
501
502       this->got_plt_ = new Output_data_space(4, "** GOT PLT");
503       layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
504                                       (elfcpp::SHF_ALLOC
505                                        | elfcpp::SHF_WRITE),
506                                       this->got_plt_, false, false, false,
507                                       true);
508
509       // The first three entries are reserved.
510       this->got_plt_->set_current_data_size(3 * 4);
511
512       // Those bytes can go into the relro segment.
513       layout->increase_relro(3 * 4);
514
515       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
516       this->global_offset_table_ =
517         symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
518                                       Symbol_table::PREDEFINED,
519                                       this->got_plt_,
520                                       0, 0, elfcpp::STT_OBJECT,
521                                       elfcpp::STB_LOCAL,
522                                       elfcpp::STV_HIDDEN, 0,
523                                       false, false);
524     }
525
526   return this->got_;
527 }
528
529 // Get the dynamic reloc section, creating it if necessary.
530
531 Target_i386::Reloc_section*
532 Target_i386::rel_dyn_section(Layout* layout)
533 {
534   if (this->rel_dyn_ == NULL)
535     {
536       gold_assert(layout != NULL);
537       this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
538       layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
539                                       elfcpp::SHF_ALLOC, this->rel_dyn_, true,
540                                       false, false, false);
541     }
542   return this->rel_dyn_;
543 }
544
545 // A class to handle the PLT data.
546
547 class Output_data_plt_i386 : public Output_section_data
548 {
549  public:
550   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
551
552   Output_data_plt_i386(Layout*, Output_data_space*);
553
554   // Add an entry to the PLT.
555   void
556   add_entry(Symbol* gsym);
557
558   // Return the .rel.plt section data.
559   const Reloc_section*
560   rel_plt() const
561   { return this->rel_; }
562
563   // Return where the TLS_DESC relocations should go.
564   Reloc_section*
565   rel_tls_desc(Layout*);
566
567  protected:
568   void
569   do_adjust_output_section(Output_section* os);
570
571   // Write to a map file.
572   void
573   do_print_to_mapfile(Mapfile* mapfile) const
574   { mapfile->print_output_data(this, _("** PLT")); }
575
576  private:
577   // The size of an entry in the PLT.
578   static const int plt_entry_size = 16;
579
580   // The first entry in the PLT for an executable.
581   static unsigned char exec_first_plt_entry[plt_entry_size];
582
583   // The first entry in the PLT for a shared object.
584   static unsigned char dyn_first_plt_entry[plt_entry_size];
585
586   // Other entries in the PLT for an executable.
587   static unsigned char exec_plt_entry[plt_entry_size];
588
589   // Other entries in the PLT for a shared object.
590   static unsigned char dyn_plt_entry[plt_entry_size];
591
592   // Set the final size.
593   void
594   set_final_data_size()
595   { this->set_data_size((this->count_ + 1) * plt_entry_size); }
596
597   // Write out the PLT data.
598   void
599   do_write(Output_file*);
600
601   // The reloc section.
602   Reloc_section* rel_;
603   // The TLS_DESC relocations, if necessary.  These must follow the
604   // regular PLT relocs.
605   Reloc_section* tls_desc_rel_;
606   // The .got.plt section.
607   Output_data_space* got_plt_;
608   // The number of PLT entries.
609   unsigned int count_;
610 };
611
612 // Create the PLT section.  The ordinary .got section is an argument,
613 // since we need to refer to the start.  We also create our own .got
614 // section just for PLT entries.
615
616 Output_data_plt_i386::Output_data_plt_i386(Layout* layout,
617                                            Output_data_space* got_plt)
618   : Output_section_data(4), tls_desc_rel_(NULL), got_plt_(got_plt), count_(0)
619 {
620   this->rel_ = new Reloc_section(false);
621   layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
622                                   elfcpp::SHF_ALLOC, this->rel_, true,
623                                   false, false, false);
624 }
625
626 void
627 Output_data_plt_i386::do_adjust_output_section(Output_section* os)
628 {
629   // UnixWare sets the entsize of .plt to 4, and so does the old GNU
630   // linker, and so do we.
631   os->set_entsize(4);
632 }
633
634 // Add an entry to the PLT.
635
636 void
637 Output_data_plt_i386::add_entry(Symbol* gsym)
638 {
639   gold_assert(!gsym->has_plt_offset());
640
641   // Note that when setting the PLT offset we skip the initial
642   // reserved PLT entry.
643   gsym->set_plt_offset((this->count_ + 1) * plt_entry_size);
644
645   ++this->count_;
646
647   section_offset_type got_offset = this->got_plt_->current_data_size();
648
649   // Every PLT entry needs a GOT entry which points back to the PLT
650   // entry (this will be changed by the dynamic linker, normally
651   // lazily when the function is called).
652   this->got_plt_->set_current_data_size(got_offset + 4);
653
654   // Every PLT entry needs a reloc.
655   gsym->set_needs_dynsym_entry();
656   this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_,
657                          got_offset);
658
659   // Note that we don't need to save the symbol.  The contents of the
660   // PLT are independent of which symbols are used.  The symbols only
661   // appear in the relocations.
662 }
663
664 // Return where the TLS_DESC relocations should go, creating it if
665 // necessary. These follow the JUMP_SLOT relocations.
666
667 Output_data_plt_i386::Reloc_section*
668 Output_data_plt_i386::rel_tls_desc(Layout* layout)
669 {
670   if (this->tls_desc_rel_ == NULL)
671     {
672       this->tls_desc_rel_ = new Reloc_section(false);
673       layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
674                                       elfcpp::SHF_ALLOC, this->tls_desc_rel_,
675                                       true, false, false, false);
676       gold_assert(this->tls_desc_rel_->output_section() ==
677                   this->rel_->output_section());
678     }
679   return this->tls_desc_rel_;
680 }
681
682 // The first entry in the PLT for an executable.
683
684 unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] =
685 {
686   0xff, 0x35,   // pushl contents of memory address
687   0, 0, 0, 0,   // replaced with address of .got + 4
688   0xff, 0x25,   // jmp indirect
689   0, 0, 0, 0,   // replaced with address of .got + 8
690   0, 0, 0, 0    // unused
691 };
692
693 // The first entry in the PLT for a shared object.
694
695 unsigned char Output_data_plt_i386::dyn_first_plt_entry[plt_entry_size] =
696 {
697   0xff, 0xb3, 4, 0, 0, 0,       // pushl 4(%ebx)
698   0xff, 0xa3, 8, 0, 0, 0,       // jmp *8(%ebx)
699   0, 0, 0, 0                    // unused
700 };
701
702 // Subsequent entries in the PLT for an executable.
703
704 unsigned char Output_data_plt_i386::exec_plt_entry[plt_entry_size] =
705 {
706   0xff, 0x25,   // jmp indirect
707   0, 0, 0, 0,   // replaced with address of symbol in .got
708   0x68,         // pushl immediate
709   0, 0, 0, 0,   // replaced with offset into relocation table
710   0xe9,         // jmp relative
711   0, 0, 0, 0    // replaced with offset to start of .plt
712 };
713
714 // Subsequent entries in the PLT for a shared object.
715
716 unsigned char Output_data_plt_i386::dyn_plt_entry[plt_entry_size] =
717 {
718   0xff, 0xa3,   // jmp *offset(%ebx)
719   0, 0, 0, 0,   // replaced with offset of symbol in .got
720   0x68,         // pushl immediate
721   0, 0, 0, 0,   // replaced with offset into relocation table
722   0xe9,         // jmp relative
723   0, 0, 0, 0    // replaced with offset to start of .plt
724 };
725
726 // Write out the PLT.  This uses the hand-coded instructions above,
727 // and adjusts them as needed.  This is all specified by the i386 ELF
728 // Processor Supplement.
729
730 void
731 Output_data_plt_i386::do_write(Output_file* of)
732 {
733   const off_t offset = this->offset();
734   const section_size_type oview_size =
735     convert_to_section_size_type(this->data_size());
736   unsigned char* const oview = of->get_output_view(offset, oview_size);
737
738   const off_t got_file_offset = this->got_plt_->offset();
739   const section_size_type got_size =
740     convert_to_section_size_type(this->got_plt_->data_size());
741   unsigned char* const got_view = of->get_output_view(got_file_offset,
742                                                       got_size);
743
744   unsigned char* pov = oview;
745
746   elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address();
747   elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address();
748
749   if (parameters->options().output_is_position_independent())
750     memcpy(pov, dyn_first_plt_entry, plt_entry_size);
751   else
752     {
753       memcpy(pov, exec_first_plt_entry, plt_entry_size);
754       elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
755       elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
756     }
757   pov += plt_entry_size;
758
759   unsigned char* got_pov = got_view;
760
761   memset(got_pov, 0, 12);
762   got_pov += 12;
763
764   const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
765
766   unsigned int plt_offset = plt_entry_size;
767   unsigned int plt_rel_offset = 0;
768   unsigned int got_offset = 12;
769   const unsigned int count = this->count_;
770   for (unsigned int i = 0;
771        i < count;
772        ++i,
773          pov += plt_entry_size,
774          got_pov += 4,
775          plt_offset += plt_entry_size,
776          plt_rel_offset += rel_size,
777          got_offset += 4)
778     {
779       // Set and adjust the PLT entry itself.
780
781       if (parameters->options().output_is_position_independent())
782         {
783           memcpy(pov, dyn_plt_entry, plt_entry_size);
784           elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
785         }
786       else
787         {
788           memcpy(pov, exec_plt_entry, plt_entry_size);
789           elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
790                                                       (got_address
791                                                        + got_offset));
792         }
793
794       elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
795       elfcpp::Swap<32, false>::writeval(pov + 12,
796                                         - (plt_offset + plt_entry_size));
797
798       // Set the entry in the GOT.
799       elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6);
800     }
801
802   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
803   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
804
805   of->write_output_view(offset, oview_size, oview);
806   of->write_output_view(got_file_offset, got_size, got_view);
807 }
808
809 // Create a PLT entry for a global symbol.
810
811 void
812 Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym)
813 {
814   if (gsym->has_plt_offset())
815     return;
816
817   if (this->plt_ == NULL)
818     {
819       // Create the GOT sections first.
820       this->got_section(symtab, layout);
821
822       this->plt_ = new Output_data_plt_i386(layout, this->got_plt_);
823       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
824                                       (elfcpp::SHF_ALLOC
825                                        | elfcpp::SHF_EXECINSTR),
826                                       this->plt_, false, false, false, false);
827     }
828
829   this->plt_->add_entry(gsym);
830 }
831
832 // Get the section to use for TLS_DESC relocations.
833
834 Target_i386::Reloc_section*
835 Target_i386::rel_tls_desc_section(Layout* layout) const
836 {
837   return this->plt_section()->rel_tls_desc(layout);
838 }
839
840 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
841
842 void
843 Target_i386::define_tls_base_symbol(Symbol_table* symtab, Layout* layout)
844 {
845   if (this->tls_base_symbol_defined_)
846     return;
847
848   Output_segment* tls_segment = layout->tls_segment();
849   if (tls_segment != NULL)
850     {
851       bool is_exec = parameters->options().output_is_executable();
852       symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
853                                        Symbol_table::PREDEFINED,
854                                        tls_segment, 0, 0,
855                                        elfcpp::STT_TLS,
856                                        elfcpp::STB_LOCAL,
857                                        elfcpp::STV_HIDDEN, 0,
858                                        (is_exec
859                                         ? Symbol::SEGMENT_END
860                                         : Symbol::SEGMENT_START),
861                                        true);
862     }
863   this->tls_base_symbol_defined_ = true;
864 }
865
866 // Create a GOT entry for the TLS module index.
867
868 unsigned int
869 Target_i386::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
870                                  Sized_relobj<32, false>* object)
871 {
872   if (this->got_mod_index_offset_ == -1U)
873     {
874       gold_assert(symtab != NULL && layout != NULL && object != NULL);
875       Reloc_section* rel_dyn = this->rel_dyn_section(layout);
876       Output_data_got<32, false>* got = this->got_section(symtab, layout);
877       unsigned int got_offset = got->add_constant(0);
878       rel_dyn->add_local(object, 0, elfcpp::R_386_TLS_DTPMOD32, got,
879                          got_offset);
880       got->add_constant(0);
881       this->got_mod_index_offset_ = got_offset;
882     }
883   return this->got_mod_index_offset_;
884 }
885
886 // Optimize the TLS relocation type based on what we know about the
887 // symbol.  IS_FINAL is true if the final address of this symbol is
888 // known at link time.
889
890 tls::Tls_optimization
891 Target_i386::optimize_tls_reloc(bool is_final, int r_type)
892 {
893   // If we are generating a shared library, then we can't do anything
894   // in the linker.
895   if (parameters->options().shared())
896     return tls::TLSOPT_NONE;
897
898   switch (r_type)
899     {
900     case elfcpp::R_386_TLS_GD:
901     case elfcpp::R_386_TLS_GOTDESC:
902     case elfcpp::R_386_TLS_DESC_CALL:
903       // These are General-Dynamic which permits fully general TLS
904       // access.  Since we know that we are generating an executable,
905       // we can convert this to Initial-Exec.  If we also know that
906       // this is a local symbol, we can further switch to Local-Exec.
907       if (is_final)
908         return tls::TLSOPT_TO_LE;
909       return tls::TLSOPT_TO_IE;
910
911     case elfcpp::R_386_TLS_LDM:
912       // This is Local-Dynamic, which refers to a local symbol in the
913       // dynamic TLS block.  Since we know that we generating an
914       // executable, we can switch to Local-Exec.
915       return tls::TLSOPT_TO_LE;
916
917     case elfcpp::R_386_TLS_LDO_32:
918       // Another type of Local-Dynamic relocation.
919       return tls::TLSOPT_TO_LE;
920
921     case elfcpp::R_386_TLS_IE:
922     case elfcpp::R_386_TLS_GOTIE:
923     case elfcpp::R_386_TLS_IE_32:
924       // These are Initial-Exec relocs which get the thread offset
925       // from the GOT.  If we know that we are linking against the
926       // local symbol, we can switch to Local-Exec, which links the
927       // thread offset into the instruction.
928       if (is_final)
929         return tls::TLSOPT_TO_LE;
930       return tls::TLSOPT_NONE;
931
932     case elfcpp::R_386_TLS_LE:
933     case elfcpp::R_386_TLS_LE_32:
934       // When we already have Local-Exec, there is nothing further we
935       // can do.
936       return tls::TLSOPT_NONE;
937
938     default:
939       gold_unreachable();
940     }
941 }
942
943 // Report an unsupported relocation against a local symbol.
944
945 void
946 Target_i386::Scan::unsupported_reloc_local(Sized_relobj<32, false>* object,
947                                            unsigned int r_type)
948 {
949   gold_error(_("%s: unsupported reloc %u against local symbol"),
950              object->name().c_str(), r_type);
951 }
952
953 // Scan a relocation for a local symbol.
954
955 inline void
956 Target_i386::Scan::local(Symbol_table* symtab,
957                          Layout* layout,
958                          Target_i386* target,
959                          Sized_relobj<32, false>* object,
960                          unsigned int data_shndx,
961                          Output_section* output_section,
962                          const elfcpp::Rel<32, false>& reloc,
963                          unsigned int r_type,
964                          const elfcpp::Sym<32, false>& lsym)
965 {
966   switch (r_type)
967     {
968     case elfcpp::R_386_NONE:
969     case elfcpp::R_386_GNU_VTINHERIT:
970     case elfcpp::R_386_GNU_VTENTRY:
971       break;
972
973     case elfcpp::R_386_32:
974       // If building a shared library (or a position-independent
975       // executable), we need to create a dynamic relocation for
976       // this location. The relocation applied at link time will
977       // apply the link-time value, so we flag the location with
978       // an R_386_RELATIVE relocation so the dynamic loader can
979       // relocate it easily.
980       if (parameters->options().output_is_position_independent())
981         {
982           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
983           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
984           rel_dyn->add_local_relative(object, r_sym, elfcpp::R_386_RELATIVE,
985                                       output_section, data_shndx,
986                                       reloc.get_r_offset());
987         }
988       break;
989
990     case elfcpp::R_386_16:
991     case elfcpp::R_386_8:
992       // If building a shared library (or a position-independent
993       // executable), we need to create a dynamic relocation for
994       // this location. Because the addend needs to remain in the
995       // data section, we need to be careful not to apply this
996       // relocation statically.
997       if (parameters->options().output_is_position_independent())
998         {
999           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1000           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1001           if (lsym.get_st_type() != elfcpp::STT_SECTION)
1002             rel_dyn->add_local(object, r_sym, r_type, output_section,
1003                                data_shndx, reloc.get_r_offset());
1004           else
1005             {
1006               gold_assert(lsym.get_st_value() == 0);
1007               unsigned int shndx = lsym.get_st_shndx();
1008               bool is_ordinary;
1009               shndx = object->adjust_sym_shndx(r_sym, shndx,
1010                                                &is_ordinary);
1011               if (!is_ordinary)
1012                 object->error(_("section symbol %u has bad shndx %u"),
1013                               r_sym, shndx);
1014               else
1015                 rel_dyn->add_local_section(object, shndx,
1016                                            r_type, output_section,
1017                                            data_shndx, reloc.get_r_offset());
1018             }
1019         }
1020       break;
1021
1022     case elfcpp::R_386_PC32:
1023     case elfcpp::R_386_PC16:
1024     case elfcpp::R_386_PC8:
1025       break;
1026
1027     case elfcpp::R_386_PLT32:
1028       // Since we know this is a local symbol, we can handle this as a
1029       // PC32 reloc.
1030       break;
1031
1032     case elfcpp::R_386_GOTOFF:
1033     case elfcpp::R_386_GOTPC:
1034       // We need a GOT section.
1035       target->got_section(symtab, layout);
1036       break;
1037
1038     case elfcpp::R_386_GOT32:
1039       {
1040         // The symbol requires a GOT entry.
1041         Output_data_got<32, false>* got = target->got_section(symtab, layout);
1042         unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1043         if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
1044           {
1045             // If we are generating a shared object, we need to add a
1046             // dynamic RELATIVE relocation for this symbol's GOT entry.
1047             if (parameters->options().output_is_position_independent())
1048               {
1049                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1050                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1051                 rel_dyn->add_local_relative(
1052                     object, r_sym, elfcpp::R_386_RELATIVE, got,
1053                     object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
1054               }
1055           }
1056       }
1057       break;
1058
1059       // These are relocations which should only be seen by the
1060       // dynamic linker, and should never be seen here.
1061     case elfcpp::R_386_COPY:
1062     case elfcpp::R_386_GLOB_DAT:
1063     case elfcpp::R_386_JUMP_SLOT:
1064     case elfcpp::R_386_RELATIVE:
1065     case elfcpp::R_386_TLS_TPOFF:
1066     case elfcpp::R_386_TLS_DTPMOD32:
1067     case elfcpp::R_386_TLS_DTPOFF32:
1068     case elfcpp::R_386_TLS_TPOFF32:
1069     case elfcpp::R_386_TLS_DESC:
1070       gold_error(_("%s: unexpected reloc %u in object file"),
1071                  object->name().c_str(), r_type);
1072       break;
1073
1074       // These are initial TLS relocs, which are expected when
1075       // linking.
1076     case elfcpp::R_386_TLS_GD:            // Global-dynamic
1077     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
1078     case elfcpp::R_386_TLS_DESC_CALL:
1079     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
1080     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
1081     case elfcpp::R_386_TLS_IE:            // Initial-exec
1082     case elfcpp::R_386_TLS_IE_32:
1083     case elfcpp::R_386_TLS_GOTIE:
1084     case elfcpp::R_386_TLS_LE:            // Local-exec
1085     case elfcpp::R_386_TLS_LE_32:
1086       {
1087         bool output_is_shared = parameters->options().shared();
1088         const tls::Tls_optimization optimized_type
1089             = Target_i386::optimize_tls_reloc(!output_is_shared, r_type);
1090         switch (r_type)
1091           {
1092           case elfcpp::R_386_TLS_GD:          // Global-dynamic
1093             if (optimized_type == tls::TLSOPT_NONE)
1094               {
1095                 // Create a pair of GOT entries for the module index and
1096                 // dtv-relative offset.
1097                 Output_data_got<32, false>* got
1098                     = target->got_section(symtab, layout);
1099                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1100                 unsigned int shndx = lsym.get_st_shndx();
1101                 bool is_ordinary;
1102                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1103                 if (!is_ordinary)
1104                   object->error(_("local symbol %u has bad shndx %u"),
1105                               r_sym, shndx);
1106                 else
1107                   got->add_local_pair_with_rel(object, r_sym, shndx,
1108                                                GOT_TYPE_TLS_PAIR,
1109                                                target->rel_dyn_section(layout),
1110                                                elfcpp::R_386_TLS_DTPMOD32, 0);
1111               }
1112             else if (optimized_type != tls::TLSOPT_TO_LE)
1113               unsupported_reloc_local(object, r_type);
1114             break;
1115
1116           case elfcpp::R_386_TLS_GOTDESC:     // Global-dynamic (from ~oliva)
1117             target->define_tls_base_symbol(symtab, layout);
1118             if (optimized_type == tls::TLSOPT_NONE)
1119               {
1120                 // Create a double GOT entry with an R_386_TLS_DESC reloc.
1121                 Output_data_got<32, false>* got
1122                     = target->got_section(symtab, layout);
1123                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1124                 if (!object->local_has_got_offset(r_sym, GOT_TYPE_TLS_DESC))
1125                   {
1126                     unsigned int got_offset = got->add_constant(0);
1127                     // The local symbol value is stored in the second
1128                     // GOT entry.
1129                     got->add_local(object, r_sym, GOT_TYPE_TLS_DESC);
1130                     // That set the GOT offset of the local symbol to
1131                     // point to the second entry, but we want it to
1132                     // point to the first.
1133                     object->set_local_got_offset(r_sym, GOT_TYPE_TLS_DESC,
1134                                                  got_offset);
1135                     Reloc_section* rt = target->rel_tls_desc_section(layout);
1136                     rt->add_absolute(elfcpp::R_386_TLS_DESC, got, got_offset);
1137                   }
1138               }
1139             else if (optimized_type != tls::TLSOPT_TO_LE)
1140               unsupported_reloc_local(object, r_type);
1141             break;
1142
1143           case elfcpp::R_386_TLS_DESC_CALL:
1144             break;
1145
1146           case elfcpp::R_386_TLS_LDM:         // Local-dynamic
1147             if (optimized_type == tls::TLSOPT_NONE)
1148               {
1149                 // Create a GOT entry for the module index.
1150                 target->got_mod_index_entry(symtab, layout, object);
1151               }
1152             else if (optimized_type != tls::TLSOPT_TO_LE)
1153               unsupported_reloc_local(object, r_type);
1154             break;
1155
1156           case elfcpp::R_386_TLS_LDO_32:      // Alternate local-dynamic
1157             break;
1158
1159           case elfcpp::R_386_TLS_IE:          // Initial-exec
1160           case elfcpp::R_386_TLS_IE_32:
1161           case elfcpp::R_386_TLS_GOTIE:
1162             layout->set_has_static_tls();
1163             if (optimized_type == tls::TLSOPT_NONE)
1164               {
1165                 // For the R_386_TLS_IE relocation, we need to create a
1166                 // dynamic relocation when building a shared library.
1167                 if (r_type == elfcpp::R_386_TLS_IE
1168                     && parameters->options().shared())
1169                   {
1170                     Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1171                     unsigned int r_sym
1172                         = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1173                     rel_dyn->add_local_relative(object, r_sym,
1174                                                 elfcpp::R_386_RELATIVE,
1175                                                 output_section, data_shndx,
1176                                                 reloc.get_r_offset());
1177                   }
1178                 // Create a GOT entry for the tp-relative offset.
1179                 Output_data_got<32, false>* got
1180                     = target->got_section(symtab, layout);
1181                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1182                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
1183                                            ? elfcpp::R_386_TLS_TPOFF32
1184                                            : elfcpp::R_386_TLS_TPOFF);
1185                 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
1186                                          ? GOT_TYPE_TLS_OFFSET
1187                                          : GOT_TYPE_TLS_NOFFSET);
1188                 got->add_local_with_rel(object, r_sym, got_type,
1189                                         target->rel_dyn_section(layout),
1190                                         dyn_r_type);
1191               }
1192             else if (optimized_type != tls::TLSOPT_TO_LE)
1193               unsupported_reloc_local(object, r_type);
1194             break;
1195
1196           case elfcpp::R_386_TLS_LE:          // Local-exec
1197           case elfcpp::R_386_TLS_LE_32:
1198             layout->set_has_static_tls();
1199             if (output_is_shared)
1200               {
1201                 // We need to create a dynamic relocation.
1202                 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
1203                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1204                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
1205                                            ? elfcpp::R_386_TLS_TPOFF32
1206                                            : elfcpp::R_386_TLS_TPOFF);
1207                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1208                 rel_dyn->add_local(object, r_sym, dyn_r_type, output_section,
1209                                    data_shndx, reloc.get_r_offset());
1210               }
1211             break;
1212
1213           default:
1214             gold_unreachable();
1215           }
1216       }
1217       break;
1218
1219     case elfcpp::R_386_32PLT:
1220     case elfcpp::R_386_TLS_GD_32:
1221     case elfcpp::R_386_TLS_GD_PUSH:
1222     case elfcpp::R_386_TLS_GD_CALL:
1223     case elfcpp::R_386_TLS_GD_POP:
1224     case elfcpp::R_386_TLS_LDM_32:
1225     case elfcpp::R_386_TLS_LDM_PUSH:
1226     case elfcpp::R_386_TLS_LDM_CALL:
1227     case elfcpp::R_386_TLS_LDM_POP:
1228     case elfcpp::R_386_USED_BY_INTEL_200:
1229     default:
1230       unsupported_reloc_local(object, r_type);
1231       break;
1232     }
1233 }
1234
1235 // Report an unsupported relocation against a global symbol.
1236
1237 void
1238 Target_i386::Scan::unsupported_reloc_global(Sized_relobj<32, false>* object,
1239                                             unsigned int r_type,
1240                                             Symbol* gsym)
1241 {
1242   gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1243              object->name().c_str(), r_type, gsym->demangled_name().c_str());
1244 }
1245
1246 inline bool
1247 Target_i386::Scan::possible_function_pointer_reloc(unsigned int r_type)
1248 {
1249   switch (r_type)
1250     {
1251     case elfcpp::R_386_32:
1252     case elfcpp::R_386_16:
1253     case elfcpp::R_386_8:
1254     case elfcpp::R_386_GOTOFF:
1255     case elfcpp::R_386_GOT32:
1256       {
1257         return true;
1258       }
1259     default:
1260       return false;
1261     }
1262   return false;
1263 }
1264
1265 inline bool
1266 Target_i386::Scan::local_reloc_may_be_function_pointer(
1267   Symbol_table* ,
1268   Layout* ,
1269   Target_i386* ,
1270   Sized_relobj<32, false>* ,
1271   unsigned int ,
1272   Output_section* ,
1273   const elfcpp::Rel<32, false>& ,
1274   unsigned int r_type,
1275   const elfcpp::Sym<32, false>&)
1276 {
1277   return possible_function_pointer_reloc(r_type);
1278 }
1279
1280 inline bool
1281 Target_i386::Scan::global_reloc_may_be_function_pointer(
1282   Symbol_table* ,
1283   Layout* ,
1284   Target_i386* ,
1285   Sized_relobj<32, false>* ,
1286   unsigned int ,
1287   Output_section* ,
1288   const elfcpp::Rel<32, false>& ,
1289   unsigned int r_type,
1290   Symbol*)
1291 {
1292   return possible_function_pointer_reloc(r_type);
1293 }
1294
1295 // Scan a relocation for a global symbol.
1296
1297 inline void
1298 Target_i386::Scan::global(Symbol_table* symtab,
1299                           Layout* layout,
1300                           Target_i386* target,
1301                           Sized_relobj<32, false>* object,
1302                           unsigned int data_shndx,
1303                           Output_section* output_section,
1304                           const elfcpp::Rel<32, false>& reloc,
1305                           unsigned int r_type,
1306                           Symbol* gsym)
1307 {
1308   switch (r_type)
1309     {
1310     case elfcpp::R_386_NONE:
1311     case elfcpp::R_386_GNU_VTINHERIT:
1312     case elfcpp::R_386_GNU_VTENTRY:
1313       break;
1314
1315     case elfcpp::R_386_32:
1316     case elfcpp::R_386_16:
1317     case elfcpp::R_386_8:
1318       {
1319         // Make a PLT entry if necessary.
1320         if (gsym->needs_plt_entry())
1321           {
1322             target->make_plt_entry(symtab, layout, gsym);
1323             // Since this is not a PC-relative relocation, we may be
1324             // taking the address of a function. In that case we need to
1325             // set the entry in the dynamic symbol table to the address of
1326             // the PLT entry.
1327             if (gsym->is_from_dynobj() && !parameters->options().shared())
1328               gsym->set_needs_dynsym_value();
1329           }
1330         // Make a dynamic relocation if necessary.
1331         if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
1332           {
1333             if (gsym->may_need_copy_reloc())
1334               {
1335                 target->copy_reloc(symtab, layout, object,
1336                                    data_shndx, output_section, gsym, reloc);
1337               }
1338             else if (r_type == elfcpp::R_386_32
1339                      && gsym->can_use_relative_reloc(false))
1340               {
1341                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1342                 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1343                                              output_section, object,
1344                                              data_shndx, reloc.get_r_offset());
1345               }
1346             else
1347               {
1348                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1349                 rel_dyn->add_global(gsym, r_type, output_section, object,
1350                                     data_shndx, reloc.get_r_offset());
1351               }
1352           }
1353       }
1354       break;
1355
1356     case elfcpp::R_386_PC32:
1357     case elfcpp::R_386_PC16:
1358     case elfcpp::R_386_PC8:
1359       {
1360         // Make a PLT entry if necessary.
1361         if (gsym->needs_plt_entry())
1362           {
1363             // These relocations are used for function calls only in
1364             // non-PIC code.  For a 32-bit relocation in a shared library,
1365             // we'll need a text relocation anyway, so we can skip the
1366             // PLT entry and let the dynamic linker bind the call directly
1367             // to the target.  For smaller relocations, we should use a
1368             // PLT entry to ensure that the call can reach.
1369             if (!parameters->options().shared()
1370                 || r_type != elfcpp::R_386_PC32)
1371               target->make_plt_entry(symtab, layout, gsym);
1372           }
1373         // Make a dynamic relocation if necessary.
1374         int flags = Symbol::NON_PIC_REF;
1375         if (gsym->is_func())
1376           flags |= Symbol::FUNCTION_CALL;
1377         if (gsym->needs_dynamic_reloc(flags))
1378           {
1379             if (gsym->may_need_copy_reloc())
1380               {
1381                 target->copy_reloc(symtab, layout, object,
1382                                    data_shndx, output_section, gsym, reloc);
1383               }
1384             else
1385               {
1386                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1387                 rel_dyn->add_global(gsym, r_type, output_section, object,
1388                                     data_shndx, reloc.get_r_offset());
1389               }
1390           }
1391       }
1392       break;
1393
1394     case elfcpp::R_386_GOT32:
1395       {
1396         // The symbol requires a GOT entry.
1397         Output_data_got<32, false>* got = target->got_section(symtab, layout);
1398         if (gsym->final_value_is_known())
1399           got->add_global(gsym, GOT_TYPE_STANDARD);
1400         else
1401           {
1402             // If this symbol is not fully resolved, we need to add a
1403             // GOT entry with a dynamic relocation.
1404             Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1405             if (gsym->is_from_dynobj()
1406                 || gsym->is_undefined()
1407                 || gsym->is_preemptible())
1408               got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
1409                                        rel_dyn, elfcpp::R_386_GLOB_DAT);
1410             else
1411               {
1412                 if (got->add_global(gsym, GOT_TYPE_STANDARD))
1413                   rel_dyn->add_global_relative(
1414                       gsym, elfcpp::R_386_RELATIVE, got,
1415                       gsym->got_offset(GOT_TYPE_STANDARD));
1416               }
1417           }
1418       }
1419       break;
1420
1421     case elfcpp::R_386_PLT32:
1422       // If the symbol is fully resolved, this is just a PC32 reloc.
1423       // Otherwise we need a PLT entry.
1424       if (gsym->final_value_is_known())
1425         break;
1426       // If building a shared library, we can also skip the PLT entry
1427       // if the symbol is defined in the output file and is protected
1428       // or hidden.
1429       if (gsym->is_defined()
1430           && !gsym->is_from_dynobj()
1431           && !gsym->is_preemptible())
1432         break;
1433       target->make_plt_entry(symtab, layout, gsym);
1434       break;
1435
1436     case elfcpp::R_386_GOTOFF:
1437     case elfcpp::R_386_GOTPC:
1438       // We need a GOT section.
1439       target->got_section(symtab, layout);
1440       break;
1441
1442       // These are relocations which should only be seen by the
1443       // dynamic linker, and should never be seen here.
1444     case elfcpp::R_386_COPY:
1445     case elfcpp::R_386_GLOB_DAT:
1446     case elfcpp::R_386_JUMP_SLOT:
1447     case elfcpp::R_386_RELATIVE:
1448     case elfcpp::R_386_TLS_TPOFF:
1449     case elfcpp::R_386_TLS_DTPMOD32:
1450     case elfcpp::R_386_TLS_DTPOFF32:
1451     case elfcpp::R_386_TLS_TPOFF32:
1452     case elfcpp::R_386_TLS_DESC:
1453       gold_error(_("%s: unexpected reloc %u in object file"),
1454                  object->name().c_str(), r_type);
1455       break;
1456
1457       // These are initial tls relocs, which are expected when
1458       // linking.
1459     case elfcpp::R_386_TLS_GD:            // Global-dynamic
1460     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
1461     case elfcpp::R_386_TLS_DESC_CALL:
1462     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
1463     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
1464     case elfcpp::R_386_TLS_IE:            // Initial-exec
1465     case elfcpp::R_386_TLS_IE_32:
1466     case elfcpp::R_386_TLS_GOTIE:
1467     case elfcpp::R_386_TLS_LE:            // Local-exec
1468     case elfcpp::R_386_TLS_LE_32:
1469       {
1470         const bool is_final = gsym->final_value_is_known();
1471         const tls::Tls_optimization optimized_type
1472             = Target_i386::optimize_tls_reloc(is_final, r_type);
1473         switch (r_type)
1474           {
1475           case elfcpp::R_386_TLS_GD:          // Global-dynamic
1476             if (optimized_type == tls::TLSOPT_NONE)
1477               {
1478                 // Create a pair of GOT entries for the module index and
1479                 // dtv-relative offset.
1480                 Output_data_got<32, false>* got
1481                     = target->got_section(symtab, layout);
1482                 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
1483                                              target->rel_dyn_section(layout),
1484                                              elfcpp::R_386_TLS_DTPMOD32,
1485                                              elfcpp::R_386_TLS_DTPOFF32);
1486               }
1487             else if (optimized_type == tls::TLSOPT_TO_IE)
1488               {
1489                 // Create a GOT entry for the tp-relative offset.
1490                 Output_data_got<32, false>* got
1491                     = target->got_section(symtab, layout);
1492                 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
1493                                          target->rel_dyn_section(layout),
1494                                          elfcpp::R_386_TLS_TPOFF);
1495               }
1496             else if (optimized_type != tls::TLSOPT_TO_LE)
1497               unsupported_reloc_global(object, r_type, gsym);
1498             break;
1499
1500           case elfcpp::R_386_TLS_GOTDESC:     // Global-dynamic (~oliva url)
1501             target->define_tls_base_symbol(symtab, layout);
1502             if (optimized_type == tls::TLSOPT_NONE)
1503               {
1504                 // Create a double GOT entry with an R_386_TLS_DESC reloc.
1505                 Output_data_got<32, false>* got
1506                     = target->got_section(symtab, layout);
1507                 Reloc_section* rt = target->rel_tls_desc_section(layout);
1508                 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC, rt,
1509                                              elfcpp::R_386_TLS_DESC, 0);
1510               }
1511             else if (optimized_type == tls::TLSOPT_TO_IE)
1512               {
1513                 // Create a GOT entry for the tp-relative offset.
1514                 Output_data_got<32, false>* got
1515                     = target->got_section(symtab, layout);
1516                 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
1517                                          target->rel_dyn_section(layout),
1518                                          elfcpp::R_386_TLS_TPOFF);
1519               }
1520             else if (optimized_type != tls::TLSOPT_TO_LE)
1521               unsupported_reloc_global(object, r_type, gsym);
1522             break;
1523
1524           case elfcpp::R_386_TLS_DESC_CALL:
1525             break;
1526
1527           case elfcpp::R_386_TLS_LDM:         // Local-dynamic
1528             if (optimized_type == tls::TLSOPT_NONE)
1529               {
1530                 // Create a GOT entry for the module index.
1531                 target->got_mod_index_entry(symtab, layout, object);
1532               }
1533             else if (optimized_type != tls::TLSOPT_TO_LE)
1534               unsupported_reloc_global(object, r_type, gsym);
1535             break;
1536
1537           case elfcpp::R_386_TLS_LDO_32:      // Alternate local-dynamic
1538             break;
1539
1540           case elfcpp::R_386_TLS_IE:          // Initial-exec
1541           case elfcpp::R_386_TLS_IE_32:
1542           case elfcpp::R_386_TLS_GOTIE:
1543             layout->set_has_static_tls();
1544             if (optimized_type == tls::TLSOPT_NONE)
1545               {
1546                 // For the R_386_TLS_IE relocation, we need to create a
1547                 // dynamic relocation when building a shared library.
1548                 if (r_type == elfcpp::R_386_TLS_IE
1549                     && parameters->options().shared())
1550                   {
1551                     Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1552                     rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1553                                                  output_section, object,
1554                                                  data_shndx,
1555                                                  reloc.get_r_offset());
1556                   }
1557                 // Create a GOT entry for the tp-relative offset.
1558                 Output_data_got<32, false>* got
1559                     = target->got_section(symtab, layout);
1560                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
1561                                            ? elfcpp::R_386_TLS_TPOFF32
1562                                            : elfcpp::R_386_TLS_TPOFF);
1563                 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
1564                                          ? GOT_TYPE_TLS_OFFSET
1565                                          : GOT_TYPE_TLS_NOFFSET);
1566                 got->add_global_with_rel(gsym, got_type,
1567                                          target->rel_dyn_section(layout),
1568                                          dyn_r_type);
1569               }
1570             else if (optimized_type != tls::TLSOPT_TO_LE)
1571               unsupported_reloc_global(object, r_type, gsym);
1572             break;
1573
1574           case elfcpp::R_386_TLS_LE:          // Local-exec
1575           case elfcpp::R_386_TLS_LE_32:
1576             layout->set_has_static_tls();
1577             if (parameters->options().shared())
1578               {
1579                 // We need to create a dynamic relocation.
1580                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
1581                                            ? elfcpp::R_386_TLS_TPOFF32
1582                                            : elfcpp::R_386_TLS_TPOFF);
1583                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1584                 rel_dyn->add_global(gsym, dyn_r_type, output_section, object,
1585                                     data_shndx, reloc.get_r_offset());
1586               }
1587             break;
1588
1589           default:
1590             gold_unreachable();
1591           }
1592       }
1593       break;
1594
1595     case elfcpp::R_386_32PLT:
1596     case elfcpp::R_386_TLS_GD_32:
1597     case elfcpp::R_386_TLS_GD_PUSH:
1598     case elfcpp::R_386_TLS_GD_CALL:
1599     case elfcpp::R_386_TLS_GD_POP:
1600     case elfcpp::R_386_TLS_LDM_32:
1601     case elfcpp::R_386_TLS_LDM_PUSH:
1602     case elfcpp::R_386_TLS_LDM_CALL:
1603     case elfcpp::R_386_TLS_LDM_POP:
1604     case elfcpp::R_386_USED_BY_INTEL_200:
1605     default:
1606       unsupported_reloc_global(object, r_type, gsym);
1607       break;
1608     }
1609 }
1610
1611 // Process relocations for gc.
1612
1613 void
1614 Target_i386::gc_process_relocs(Symbol_table* symtab,
1615                                Layout* layout,
1616                                Sized_relobj<32, false>* object,
1617                                unsigned int data_shndx,
1618                                unsigned int,
1619                                const unsigned char* prelocs,
1620                                size_t reloc_count,
1621                                Output_section* output_section,
1622                                bool needs_special_offset_handling,
1623                                size_t local_symbol_count,
1624                                const unsigned char* plocal_symbols)
1625 {
1626   gold::gc_process_relocs<32, false, Target_i386, elfcpp::SHT_REL,
1627                           Target_i386::Scan>(
1628     symtab,
1629     layout,
1630     this,
1631     object,
1632     data_shndx,
1633     prelocs,
1634     reloc_count,
1635     output_section,
1636     needs_special_offset_handling,
1637     local_symbol_count,
1638     plocal_symbols);
1639 }
1640
1641 // Scan relocations for a section.
1642
1643 void
1644 Target_i386::scan_relocs(Symbol_table* symtab,
1645                          Layout* layout,
1646                          Sized_relobj<32, false>* object,
1647                          unsigned int data_shndx,
1648                          unsigned int sh_type,
1649                          const unsigned char* prelocs,
1650                          size_t reloc_count,
1651                          Output_section* output_section,
1652                          bool needs_special_offset_handling,
1653                          size_t local_symbol_count,
1654                          const unsigned char* plocal_symbols)
1655 {
1656   if (sh_type == elfcpp::SHT_RELA)
1657     {
1658       gold_error(_("%s: unsupported RELA reloc section"),
1659                  object->name().c_str());
1660       return;
1661     }
1662
1663   gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL,
1664                     Target_i386::Scan>(
1665     symtab,
1666     layout,
1667     this,
1668     object,
1669     data_shndx,
1670     prelocs,
1671     reloc_count,
1672     output_section,
1673     needs_special_offset_handling,
1674     local_symbol_count,
1675     plocal_symbols);
1676 }
1677
1678 // Finalize the sections.
1679
1680 void
1681 Target_i386::do_finalize_sections(
1682     Layout* layout,
1683     const Input_objects*,
1684     Symbol_table* symtab)
1685 {
1686   const Reloc_section* rel_plt = (this->plt_ == NULL
1687                                   ? NULL
1688                                   : this->plt_->rel_plt());
1689   layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
1690                                   this->rel_dyn_, true, false);
1691
1692   // Emit any relocs we saved in an attempt to avoid generating COPY
1693   // relocs.
1694   if (this->copy_relocs_.any_saved_relocs())
1695     this->copy_relocs_.emit(this->rel_dyn_section(layout));
1696
1697   // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
1698   // the .got.plt section.
1699   Symbol* sym = this->global_offset_table_;
1700   if (sym != NULL)
1701     {
1702       uint32_t data_size = this->got_plt_->current_data_size();
1703       symtab->get_sized_symbol<32>(sym)->set_symsize(data_size);
1704     }
1705 }
1706
1707 // Return whether a direct absolute static relocation needs to be applied.
1708 // In cases where Scan::local() or Scan::global() has created
1709 // a dynamic relocation other than R_386_RELATIVE, the addend
1710 // of the relocation is carried in the data, and we must not
1711 // apply the static relocation.
1712
1713 inline bool
1714 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol<32>* gsym,
1715                                                  int ref_flags,
1716                                                  bool is_32bit,
1717                                                  Output_section* output_section)
1718 {
1719   // If the output section is not allocated, then we didn't call
1720   // scan_relocs, we didn't create a dynamic reloc, and we must apply
1721   // the reloc here.
1722   if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
1723     return true;
1724
1725   // For local symbols, we will have created a non-RELATIVE dynamic
1726   // relocation only if (a) the output is position independent,
1727   // (b) the relocation is absolute (not pc- or segment-relative), and
1728   // (c) the relocation is not 32 bits wide.
1729   if (gsym == NULL)
1730     return !(parameters->options().output_is_position_independent()
1731              && (ref_flags & Symbol::ABSOLUTE_REF)
1732              && !is_32bit);
1733
1734   // For global symbols, we use the same helper routines used in the
1735   // scan pass.  If we did not create a dynamic relocation, or if we
1736   // created a RELATIVE dynamic relocation, we should apply the static
1737   // relocation.
1738   bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
1739   bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
1740                 && gsym->can_use_relative_reloc(ref_flags
1741                                                 & Symbol::FUNCTION_CALL);
1742   return !has_dyn || is_rel;
1743 }
1744
1745 // Perform a relocation.
1746
1747 inline bool
1748 Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
1749                                 Target_i386* target,
1750                                 Output_section *output_section,
1751                                 size_t relnum,
1752                                 const elfcpp::Rel<32, false>& rel,
1753                                 unsigned int r_type,
1754                                 const Sized_symbol<32>* gsym,
1755                                 const Symbol_value<32>* psymval,
1756                                 unsigned char* view,
1757                                 elfcpp::Elf_types<32>::Elf_Addr address,
1758                                 section_size_type view_size)
1759 {
1760   if (this->skip_call_tls_get_addr_)
1761     {
1762       if ((r_type != elfcpp::R_386_PLT32
1763            && r_type != elfcpp::R_386_PC32)
1764           || gsym == NULL
1765           || strcmp(gsym->name(), "___tls_get_addr") != 0)
1766         gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1767                                _("missing expected TLS relocation"));
1768       else
1769         {
1770           this->skip_call_tls_get_addr_ = false;
1771           return false;
1772         }
1773     }
1774
1775   // Pick the value to use for symbols defined in shared objects.
1776   Symbol_value<32> symval;
1777   if (gsym != NULL
1778       && gsym->use_plt_offset(r_type == elfcpp::R_386_PC8
1779                               || r_type == elfcpp::R_386_PC16
1780                               || r_type == elfcpp::R_386_PC32))
1781     {
1782       symval.set_output_value(target->plt_section()->address()
1783                               + gsym->plt_offset());
1784       psymval = &symval;
1785     }
1786
1787   const Sized_relobj<32, false>* object = relinfo->object;
1788
1789   // Get the GOT offset if needed.
1790   // The GOT pointer points to the end of the GOT section.
1791   // We need to subtract the size of the GOT section to get
1792   // the actual offset to use in the relocation.
1793   bool have_got_offset = false;
1794   unsigned int got_offset = 0;
1795   switch (r_type)
1796     {
1797     case elfcpp::R_386_GOT32:
1798       if (gsym != NULL)
1799         {
1800           gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
1801           got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
1802                         - target->got_size());
1803         }
1804       else
1805         {
1806           unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
1807           gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
1808           got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
1809                         - target->got_size());
1810         }
1811       have_got_offset = true;
1812       break;
1813
1814     default:
1815       break;
1816     }
1817
1818   switch (r_type)
1819     {
1820     case elfcpp::R_386_NONE:
1821     case elfcpp::R_386_GNU_VTINHERIT:
1822     case elfcpp::R_386_GNU_VTENTRY:
1823       break;
1824
1825     case elfcpp::R_386_32:
1826       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
1827                                     output_section))
1828         Relocate_functions<32, false>::rel32(view, object, psymval);
1829       break;
1830
1831     case elfcpp::R_386_PC32:
1832       {
1833         int ref_flags = Symbol::NON_PIC_REF;
1834         if (gsym != NULL && gsym->is_func())
1835           ref_flags |= Symbol::FUNCTION_CALL;
1836         if (should_apply_static_reloc(gsym, ref_flags, true, output_section))
1837           Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1838       }
1839       break;
1840
1841     case elfcpp::R_386_16:
1842       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
1843                                     output_section))
1844         Relocate_functions<32, false>::rel16(view, object, psymval);
1845       break;
1846
1847     case elfcpp::R_386_PC16:
1848       {
1849         int ref_flags = Symbol::NON_PIC_REF;
1850         if (gsym != NULL && gsym->is_func())
1851           ref_flags |= Symbol::FUNCTION_CALL;
1852         if (should_apply_static_reloc(gsym, ref_flags, false, output_section))
1853           Relocate_functions<32, false>::pcrel16(view, object, psymval, address);
1854       }
1855       break;
1856
1857     case elfcpp::R_386_8:
1858       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
1859                                     output_section))
1860         Relocate_functions<32, false>::rel8(view, object, psymval);
1861       break;
1862
1863     case elfcpp::R_386_PC8:
1864       {
1865         int ref_flags = Symbol::NON_PIC_REF;
1866         if (gsym != NULL && gsym->is_func())
1867           ref_flags |= Symbol::FUNCTION_CALL;
1868         if (should_apply_static_reloc(gsym, ref_flags, false,
1869                                       output_section))
1870           Relocate_functions<32, false>::pcrel8(view, object, psymval, address);
1871       }
1872       break;
1873
1874     case elfcpp::R_386_PLT32:
1875       gold_assert(gsym == NULL
1876                   || gsym->has_plt_offset()
1877                   || gsym->final_value_is_known()
1878                   || (gsym->is_defined()
1879                       && !gsym->is_from_dynobj()
1880                       && !gsym->is_preemptible()));
1881       Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1882       break;
1883
1884     case elfcpp::R_386_GOT32:
1885       gold_assert(have_got_offset);
1886       Relocate_functions<32, false>::rel32(view, got_offset);
1887       break;
1888
1889     case elfcpp::R_386_GOTOFF:
1890       {
1891         elfcpp::Elf_types<32>::Elf_Addr value;
1892         value = (psymval->value(object, 0)
1893                  - target->got_plt_section()->address());
1894         Relocate_functions<32, false>::rel32(view, value);
1895       }
1896       break;
1897
1898     case elfcpp::R_386_GOTPC:
1899       {
1900         elfcpp::Elf_types<32>::Elf_Addr value;
1901         value = target->got_plt_section()->address();
1902         Relocate_functions<32, false>::pcrel32(view, value, address);
1903       }
1904       break;
1905
1906     case elfcpp::R_386_COPY:
1907     case elfcpp::R_386_GLOB_DAT:
1908     case elfcpp::R_386_JUMP_SLOT:
1909     case elfcpp::R_386_RELATIVE:
1910       // These are outstanding tls relocs, which are unexpected when
1911       // linking.
1912     case elfcpp::R_386_TLS_TPOFF:
1913     case elfcpp::R_386_TLS_DTPMOD32:
1914     case elfcpp::R_386_TLS_DTPOFF32:
1915     case elfcpp::R_386_TLS_TPOFF32:
1916     case elfcpp::R_386_TLS_DESC:
1917       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1918                              _("unexpected reloc %u in object file"),
1919                              r_type);
1920       break;
1921
1922       // These are initial tls relocs, which are expected when
1923       // linking.
1924     case elfcpp::R_386_TLS_GD:             // Global-dynamic
1925     case elfcpp::R_386_TLS_GOTDESC:        // Global-dynamic (from ~oliva url)
1926     case elfcpp::R_386_TLS_DESC_CALL:
1927     case elfcpp::R_386_TLS_LDM:            // Local-dynamic
1928     case elfcpp::R_386_TLS_LDO_32:         // Alternate local-dynamic
1929     case elfcpp::R_386_TLS_IE:             // Initial-exec
1930     case elfcpp::R_386_TLS_IE_32:
1931     case elfcpp::R_386_TLS_GOTIE:
1932     case elfcpp::R_386_TLS_LE:             // Local-exec
1933     case elfcpp::R_386_TLS_LE_32:
1934       this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
1935                          view, address, view_size);
1936       break;
1937
1938     case elfcpp::R_386_32PLT:
1939     case elfcpp::R_386_TLS_GD_32:
1940     case elfcpp::R_386_TLS_GD_PUSH:
1941     case elfcpp::R_386_TLS_GD_CALL:
1942     case elfcpp::R_386_TLS_GD_POP:
1943     case elfcpp::R_386_TLS_LDM_32:
1944     case elfcpp::R_386_TLS_LDM_PUSH:
1945     case elfcpp::R_386_TLS_LDM_CALL:
1946     case elfcpp::R_386_TLS_LDM_POP:
1947     case elfcpp::R_386_USED_BY_INTEL_200:
1948     default:
1949       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1950                              _("unsupported reloc %u"),
1951                              r_type);
1952       break;
1953     }
1954
1955   return true;
1956 }
1957
1958 // Perform a TLS relocation.
1959
1960 inline void
1961 Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo,
1962                                     Target_i386* target,
1963                                     size_t relnum,
1964                                     const elfcpp::Rel<32, false>& rel,
1965                                     unsigned int r_type,
1966                                     const Sized_symbol<32>* gsym,
1967                                     const Symbol_value<32>* psymval,
1968                                     unsigned char* view,
1969                                     elfcpp::Elf_types<32>::Elf_Addr,
1970                                     section_size_type view_size)
1971 {
1972   Output_segment* tls_segment = relinfo->layout->tls_segment();
1973
1974   const Sized_relobj<32, false>* object = relinfo->object;
1975
1976   elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
1977
1978   const bool is_final = (gsym == NULL
1979                          ? !parameters->options().shared()
1980                          : gsym->final_value_is_known());
1981   const tls::Tls_optimization optimized_type
1982       = Target_i386::optimize_tls_reloc(is_final, r_type);
1983   switch (r_type)
1984     {
1985     case elfcpp::R_386_TLS_GD:           // Global-dynamic
1986       if (optimized_type == tls::TLSOPT_TO_LE)
1987         {
1988           gold_assert(tls_segment != NULL);
1989           this->tls_gd_to_le(relinfo, relnum, tls_segment,
1990                              rel, r_type, value, view,
1991                              view_size);
1992           break;
1993         }
1994       else
1995         {
1996           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
1997                                    ? GOT_TYPE_TLS_NOFFSET
1998                                    : GOT_TYPE_TLS_PAIR);
1999           unsigned int got_offset;
2000           if (gsym != NULL)
2001             {
2002               gold_assert(gsym->has_got_offset(got_type));
2003               got_offset = gsym->got_offset(got_type) - target->got_size();
2004             }
2005           else
2006             {
2007               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2008               gold_assert(object->local_has_got_offset(r_sym, got_type));
2009               got_offset = (object->local_got_offset(r_sym, got_type)
2010                             - target->got_size());
2011             }
2012           if (optimized_type == tls::TLSOPT_TO_IE)
2013             {
2014               gold_assert(tls_segment != NULL);
2015               this->tls_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
2016                                  got_offset, view, view_size);
2017               break;
2018             }
2019           else if (optimized_type == tls::TLSOPT_NONE)
2020             {
2021               // Relocate the field with the offset of the pair of GOT
2022               // entries.
2023               Relocate_functions<32, false>::rel32(view, got_offset);
2024               break;
2025             }
2026         }
2027       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2028                              _("unsupported reloc %u"),
2029                              r_type);
2030       break;
2031
2032     case elfcpp::R_386_TLS_GOTDESC:      // Global-dynamic (from ~oliva url)
2033     case elfcpp::R_386_TLS_DESC_CALL:
2034       this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
2035       if (optimized_type == tls::TLSOPT_TO_LE)
2036         {
2037           gold_assert(tls_segment != NULL);
2038           this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
2039                                   rel, r_type, value, view,
2040                                   view_size);
2041           break;
2042         }
2043       else
2044         {
2045           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
2046                                    ? GOT_TYPE_TLS_NOFFSET
2047                                    : GOT_TYPE_TLS_DESC);
2048           unsigned int got_offset;
2049           if (gsym != NULL)
2050             {
2051               gold_assert(gsym->has_got_offset(got_type));
2052               got_offset = gsym->got_offset(got_type) - target->got_size();
2053             }
2054           else
2055             {
2056               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2057               gold_assert(object->local_has_got_offset(r_sym, got_type));
2058               got_offset = (object->local_got_offset(r_sym, got_type)
2059                             - target->got_size());
2060             }
2061           if (optimized_type == tls::TLSOPT_TO_IE)
2062             {
2063               gold_assert(tls_segment != NULL);
2064               this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
2065                                       got_offset, view, view_size);
2066               break;
2067             }
2068           else if (optimized_type == tls::TLSOPT_NONE)
2069             {
2070               if (r_type == elfcpp::R_386_TLS_GOTDESC)
2071                 {
2072                   // Relocate the field with the offset of the pair of GOT
2073                   // entries.
2074                   Relocate_functions<32, false>::rel32(view, got_offset);
2075                 }
2076               break;
2077             }
2078         }
2079       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2080                              _("unsupported reloc %u"),
2081                              r_type);
2082       break;
2083
2084     case elfcpp::R_386_TLS_LDM:          // Local-dynamic
2085       if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN)
2086         {
2087           gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2088                                  _("both SUN and GNU model "
2089                                    "TLS relocations"));
2090           break;
2091         }
2092       this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
2093       if (optimized_type == tls::TLSOPT_TO_LE)
2094         {
2095           gold_assert(tls_segment != NULL);
2096           this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, r_type,
2097                              value, view, view_size);
2098           break;
2099         }
2100       else if (optimized_type == tls::TLSOPT_NONE)
2101         {
2102           // Relocate the field with the offset of the GOT entry for
2103           // the module index.
2104           unsigned int got_offset;
2105           got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
2106                         - target->got_size());
2107           Relocate_functions<32, false>::rel32(view, got_offset);
2108           break;
2109         }
2110       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2111                              _("unsupported reloc %u"),
2112                              r_type);
2113       break;
2114
2115     case elfcpp::R_386_TLS_LDO_32:       // Alternate local-dynamic
2116       if (optimized_type == tls::TLSOPT_TO_LE)
2117         {
2118           // This reloc can appear in debugging sections, in which
2119           // case we must not convert to local-exec.  We decide what
2120           // to do based on whether the section is marked as
2121           // containing executable code.  That is what the GNU linker
2122           // does as well.
2123           elfcpp::Shdr<32, false> shdr(relinfo->data_shdr);
2124           if ((shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0)
2125             {
2126               gold_assert(tls_segment != NULL);
2127               value -= tls_segment->memsz();
2128             }
2129         }
2130       Relocate_functions<32, false>::rel32(view, value);
2131       break;
2132
2133     case elfcpp::R_386_TLS_IE:           // Initial-exec
2134     case elfcpp::R_386_TLS_GOTIE:
2135     case elfcpp::R_386_TLS_IE_32:
2136       if (optimized_type == tls::TLSOPT_TO_LE)
2137         {
2138           gold_assert(tls_segment != NULL);
2139           Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
2140                                               rel, r_type, value, view,
2141                                               view_size);
2142           break;
2143         }
2144       else if (optimized_type == tls::TLSOPT_NONE)
2145         {
2146           // Relocate the field with the offset of the GOT entry for
2147           // the tp-relative offset of the symbol.
2148           unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
2149                                    ? GOT_TYPE_TLS_OFFSET
2150                                    : GOT_TYPE_TLS_NOFFSET);
2151           unsigned int got_offset;
2152           if (gsym != NULL)
2153             {
2154               gold_assert(gsym->has_got_offset(got_type));
2155               got_offset = gsym->got_offset(got_type);
2156             }
2157           else
2158             {
2159               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2160               gold_assert(object->local_has_got_offset(r_sym, got_type));
2161               got_offset = object->local_got_offset(r_sym, got_type);
2162             }
2163           // For the R_386_TLS_IE relocation, we need to apply the
2164           // absolute address of the GOT entry.
2165           if (r_type == elfcpp::R_386_TLS_IE)
2166             got_offset += target->got_plt_section()->address();
2167           // All GOT offsets are relative to the end of the GOT.
2168           got_offset -= target->got_size();
2169           Relocate_functions<32, false>::rel32(view, got_offset);
2170           break;
2171         }
2172       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2173                              _("unsupported reloc %u"),
2174                              r_type);
2175       break;
2176
2177     case elfcpp::R_386_TLS_LE:           // Local-exec
2178       // If we're creating a shared library, a dynamic relocation will
2179       // have been created for this location, so do not apply it now.
2180       if (!parameters->options().shared())
2181         {
2182           gold_assert(tls_segment != NULL);
2183           value -= tls_segment->memsz();
2184           Relocate_functions<32, false>::rel32(view, value);
2185         }
2186       break;
2187
2188     case elfcpp::R_386_TLS_LE_32:
2189       // If we're creating a shared library, a dynamic relocation will
2190       // have been created for this location, so do not apply it now.
2191       if (!parameters->options().shared())
2192         {
2193           gold_assert(tls_segment != NULL);
2194           value = tls_segment->memsz() - value;
2195           Relocate_functions<32, false>::rel32(view, value);
2196         }
2197       break;
2198     }
2199 }
2200
2201 // Do a relocation in which we convert a TLS General-Dynamic to a
2202 // Local-Exec.
2203
2204 inline void
2205 Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo,
2206                                     size_t relnum,
2207                                     Output_segment* tls_segment,
2208                                     const elfcpp::Rel<32, false>& rel,
2209                                     unsigned int,
2210                                     elfcpp::Elf_types<32>::Elf_Addr value,
2211                                     unsigned char* view,
2212                                     section_size_type view_size)
2213 {
2214   // leal foo(,%reg,1),%eax; call ___tls_get_addr
2215   //  ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2216   // leal foo(%reg),%eax; call ___tls_get_addr
2217   //  ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2218
2219   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2220   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2221
2222   unsigned char op1 = view[-1];
2223   unsigned char op2 = view[-2];
2224
2225   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2226                  op2 == 0x8d || op2 == 0x04);
2227   tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2228
2229   int roff = 5;
2230
2231   if (op2 == 0x04)
2232     {
2233       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
2234       tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
2235       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2236                      ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
2237       memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2238     }
2239   else
2240     {
2241       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2242                      (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
2243       if (rel.get_r_offset() + 9 < view_size
2244           && view[9] == 0x90)
2245         {
2246           // There is a trailing nop.  Use the size byte subl.
2247           memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2248           roff = 6;
2249         }
2250       else
2251         {
2252           // Use the five byte subl.
2253           memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2254         }
2255     }
2256
2257   value = tls_segment->memsz() - value;
2258   Relocate_functions<32, false>::rel32(view + roff, value);
2259
2260   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2261   // We can skip it.
2262   this->skip_call_tls_get_addr_ = true;
2263 }
2264
2265 // Do a relocation in which we convert a TLS General-Dynamic to an
2266 // Initial-Exec.
2267
2268 inline void
2269 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info<32, false>* relinfo,
2270                                     size_t relnum,
2271                                     Output_segment*,
2272                                     const elfcpp::Rel<32, false>& rel,
2273                                     unsigned int,
2274                                     elfcpp::Elf_types<32>::Elf_Addr value,
2275                                     unsigned char* view,
2276                                     section_size_type view_size)
2277 {
2278   // leal foo(,%ebx,1),%eax; call ___tls_get_addr
2279   //  ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
2280
2281   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2282   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2283
2284   unsigned char op1 = view[-1];
2285   unsigned char op2 = view[-2];
2286
2287   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2288                  op2 == 0x8d || op2 == 0x04);
2289   tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2290
2291   int roff = 5;
2292
2293   // FIXME: For now, support only the first (SIB) form.
2294   tls::check_tls(relinfo, relnum, rel.get_r_offset(), op2 == 0x04);
2295
2296   if (op2 == 0x04)
2297     {
2298       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
2299       tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
2300       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2301                      ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
2302       memcpy(view - 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
2303     }
2304   else
2305     {
2306       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2307                      (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
2308       if (rel.get_r_offset() + 9 < view_size
2309           && view[9] == 0x90)
2310         {
2311           // FIXME: This is not the right instruction sequence.
2312           // There is a trailing nop.  Use the size byte subl.
2313           memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2314           roff = 6;
2315         }
2316       else
2317         {
2318           // FIXME: This is not the right instruction sequence.
2319           // Use the five byte subl.
2320           memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2321         }
2322     }
2323
2324   Relocate_functions<32, false>::rel32(view + roff, value);
2325
2326   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2327   // We can skip it.
2328   this->skip_call_tls_get_addr_ = true;
2329 }
2330
2331 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2332 // General-Dynamic to a Local-Exec.
2333
2334 inline void
2335 Target_i386::Relocate::tls_desc_gd_to_le(
2336     const Relocate_info<32, false>* relinfo,
2337     size_t relnum,
2338     Output_segment* tls_segment,
2339     const elfcpp::Rel<32, false>& rel,
2340     unsigned int r_type,
2341     elfcpp::Elf_types<32>::Elf_Addr value,
2342     unsigned char* view,
2343     section_size_type view_size)
2344 {
2345   if (r_type == elfcpp::R_386_TLS_GOTDESC)
2346     {
2347       // leal foo@TLSDESC(%ebx), %eax
2348       // ==> leal foo@NTPOFF, %eax
2349       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2350       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2351       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2352                      view[-2] == 0x8d && view[-1] == 0x83);
2353       view[-1] = 0x05;
2354       value -= tls_segment->memsz();
2355       Relocate_functions<32, false>::rel32(view, value);
2356     }
2357   else
2358     {
2359       // call *foo@TLSCALL(%eax)
2360       // ==> nop; nop
2361       gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
2362       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
2363       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2364                      view[0] == 0xff && view[1] == 0x10);
2365       view[0] = 0x66;
2366       view[1] = 0x90;
2367     }
2368 }
2369
2370 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2371 // General-Dynamic to an Initial-Exec.
2372
2373 inline void
2374 Target_i386::Relocate::tls_desc_gd_to_ie(
2375     const Relocate_info<32, false>* relinfo,
2376     size_t relnum,
2377     Output_segment*,
2378     const elfcpp::Rel<32, false>& rel,
2379     unsigned int r_type,
2380     elfcpp::Elf_types<32>::Elf_Addr value,
2381     unsigned char* view,
2382     section_size_type view_size)
2383 {
2384   if (r_type == elfcpp::R_386_TLS_GOTDESC)
2385     {
2386       // leal foo@TLSDESC(%ebx), %eax
2387       // ==> movl foo@GOTNTPOFF(%ebx), %eax
2388       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2389       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2390       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2391                      view[-2] == 0x8d && view[-1] == 0x83);
2392       view[-2] = 0x8b;
2393       Relocate_functions<32, false>::rel32(view, value);
2394     }
2395   else
2396     {
2397       // call *foo@TLSCALL(%eax)
2398       // ==> nop; nop
2399       gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
2400       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
2401       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2402                      view[0] == 0xff && view[1] == 0x10);
2403       view[0] = 0x66;
2404       view[1] = 0x90;
2405     }
2406 }
2407
2408 // Do a relocation in which we convert a TLS Local-Dynamic to a
2409 // Local-Exec.
2410
2411 inline void
2412 Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo,
2413                                     size_t relnum,
2414                                     Output_segment*,
2415                                     const elfcpp::Rel<32, false>& rel,
2416                                     unsigned int,
2417                                     elfcpp::Elf_types<32>::Elf_Addr,
2418                                     unsigned char* view,
2419                                     section_size_type view_size)
2420 {
2421   // leal foo(%reg), %eax; call ___tls_get_addr
2422   // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
2423
2424   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2425   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2426
2427   // FIXME: Does this test really always pass?
2428   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2429                  view[-2] == 0x8d && view[-1] == 0x83);
2430
2431   tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2432
2433   memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
2434
2435   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2436   // We can skip it.
2437   this->skip_call_tls_get_addr_ = true;
2438 }
2439
2440 // Do a relocation in which we convert a TLS Initial-Exec to a
2441 // Local-Exec.
2442
2443 inline void
2444 Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo,
2445                                     size_t relnum,
2446                                     Output_segment* tls_segment,
2447                                     const elfcpp::Rel<32, false>& rel,
2448                                     unsigned int r_type,
2449                                     elfcpp::Elf_types<32>::Elf_Addr value,
2450                                     unsigned char* view,
2451                                     section_size_type view_size)
2452 {
2453   // We have to actually change the instructions, which means that we
2454   // need to examine the opcodes to figure out which instruction we
2455   // are looking at.
2456   if (r_type == elfcpp::R_386_TLS_IE)
2457     {
2458       // movl %gs:XX,%eax  ==>  movl $YY,%eax
2459       // movl %gs:XX,%reg  ==>  movl $YY,%reg
2460       // addl %gs:XX,%reg  ==>  addl $YY,%reg
2461       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -1);
2462       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2463
2464       unsigned char op1 = view[-1];
2465       if (op1 == 0xa1)
2466         {
2467           // movl XX,%eax  ==>  movl $YY,%eax
2468           view[-1] = 0xb8;
2469         }
2470       else
2471         {
2472           tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2473
2474           unsigned char op2 = view[-2];
2475           if (op2 == 0x8b)
2476             {
2477               // movl XX,%reg  ==>  movl $YY,%reg
2478               tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2479                              (op1 & 0xc7) == 0x05);
2480               view[-2] = 0xc7;
2481               view[-1] = 0xc0 | ((op1 >> 3) & 7);
2482             }
2483           else if (op2 == 0x03)
2484             {
2485               // addl XX,%reg  ==>  addl $YY,%reg
2486               tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2487                              (op1 & 0xc7) == 0x05);
2488               view[-2] = 0x81;
2489               view[-1] = 0xc0 | ((op1 >> 3) & 7);
2490             }
2491           else
2492             tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
2493         }
2494     }
2495   else
2496     {
2497       // subl %gs:XX(%reg1),%reg2  ==>  subl $YY,%reg2
2498       // movl %gs:XX(%reg1),%reg2  ==>  movl $YY,%reg2
2499       // addl %gs:XX(%reg1),%reg2  ==>  addl $YY,$reg2
2500       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2501       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2502
2503       unsigned char op1 = view[-1];
2504       unsigned char op2 = view[-2];
2505       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2506                      (op1 & 0xc0) == 0x80 && (op1 & 7) != 4);
2507       if (op2 == 0x8b)
2508         {
2509           // movl %gs:XX(%reg1),%reg2  ==>  movl $YY,%reg2
2510           view[-2] = 0xc7;
2511           view[-1] = 0xc0 | ((op1 >> 3) & 7);
2512         }
2513       else if (op2 == 0x2b)
2514         {
2515           // subl %gs:XX(%reg1),%reg2  ==>  subl $YY,%reg2
2516           view[-2] = 0x81;
2517           view[-1] = 0xe8 | ((op1 >> 3) & 7);
2518         }
2519       else if (op2 == 0x03)
2520         {
2521           // addl %gs:XX(%reg1),%reg2  ==>  addl $YY,$reg2
2522           view[-2] = 0x81;
2523           view[-1] = 0xc0 | ((op1 >> 3) & 7);
2524         }
2525       else
2526         tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
2527     }
2528
2529   value = tls_segment->memsz() - value;
2530   if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE)
2531     value = - value;
2532
2533   Relocate_functions<32, false>::rel32(view, value);
2534 }
2535
2536 // Relocate section data.
2537
2538 void
2539 Target_i386::relocate_section(const Relocate_info<32, false>* relinfo,
2540                               unsigned int sh_type,
2541                               const unsigned char* prelocs,
2542                               size_t reloc_count,
2543                               Output_section* output_section,
2544                               bool needs_special_offset_handling,
2545                               unsigned char* view,
2546                               elfcpp::Elf_types<32>::Elf_Addr address,
2547                               section_size_type view_size,
2548                               const Reloc_symbol_changes* reloc_symbol_changes)
2549 {
2550   gold_assert(sh_type == elfcpp::SHT_REL);
2551
2552   gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL,
2553                          Target_i386::Relocate>(
2554     relinfo,
2555     this,
2556     prelocs,
2557     reloc_count,
2558     output_section,
2559     needs_special_offset_handling,
2560     view,
2561     address,
2562     view_size,
2563     reloc_symbol_changes);
2564 }
2565
2566 // Return the size of a relocation while scanning during a relocatable
2567 // link.
2568
2569 unsigned int
2570 Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
2571     unsigned int r_type,
2572     Relobj* object)
2573 {
2574   switch (r_type)
2575     {
2576     case elfcpp::R_386_NONE:
2577     case elfcpp::R_386_GNU_VTINHERIT:
2578     case elfcpp::R_386_GNU_VTENTRY:
2579     case elfcpp::R_386_TLS_GD:            // Global-dynamic
2580     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
2581     case elfcpp::R_386_TLS_DESC_CALL:
2582     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
2583     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
2584     case elfcpp::R_386_TLS_IE:            // Initial-exec
2585     case elfcpp::R_386_TLS_IE_32:
2586     case elfcpp::R_386_TLS_GOTIE:
2587     case elfcpp::R_386_TLS_LE:            // Local-exec
2588     case elfcpp::R_386_TLS_LE_32:
2589       return 0;
2590
2591     case elfcpp::R_386_32:
2592     case elfcpp::R_386_PC32:
2593     case elfcpp::R_386_GOT32:
2594     case elfcpp::R_386_PLT32:
2595     case elfcpp::R_386_GOTOFF:
2596     case elfcpp::R_386_GOTPC:
2597      return 4;
2598
2599     case elfcpp::R_386_16:
2600     case elfcpp::R_386_PC16:
2601       return 2;
2602
2603     case elfcpp::R_386_8:
2604     case elfcpp::R_386_PC8:
2605       return 1;
2606
2607       // These are relocations which should only be seen by the
2608       // dynamic linker, and should never be seen here.
2609     case elfcpp::R_386_COPY:
2610     case elfcpp::R_386_GLOB_DAT:
2611     case elfcpp::R_386_JUMP_SLOT:
2612     case elfcpp::R_386_RELATIVE:
2613     case elfcpp::R_386_TLS_TPOFF:
2614     case elfcpp::R_386_TLS_DTPMOD32:
2615     case elfcpp::R_386_TLS_DTPOFF32:
2616     case elfcpp::R_386_TLS_TPOFF32:
2617     case elfcpp::R_386_TLS_DESC:
2618       object->error(_("unexpected reloc %u in object file"), r_type);
2619       return 0;
2620
2621     case elfcpp::R_386_32PLT:
2622     case elfcpp::R_386_TLS_GD_32:
2623     case elfcpp::R_386_TLS_GD_PUSH:
2624     case elfcpp::R_386_TLS_GD_CALL:
2625     case elfcpp::R_386_TLS_GD_POP:
2626     case elfcpp::R_386_TLS_LDM_32:
2627     case elfcpp::R_386_TLS_LDM_PUSH:
2628     case elfcpp::R_386_TLS_LDM_CALL:
2629     case elfcpp::R_386_TLS_LDM_POP:
2630     case elfcpp::R_386_USED_BY_INTEL_200:
2631     default:
2632       object->error(_("unsupported reloc %u in object file"), r_type);
2633       return 0;
2634     }
2635 }
2636
2637 // Scan the relocs during a relocatable link.
2638
2639 void
2640 Target_i386::scan_relocatable_relocs(Symbol_table* symtab,
2641                                      Layout* layout,
2642                                      Sized_relobj<32, false>* object,
2643                                      unsigned int data_shndx,
2644                                      unsigned int sh_type,
2645                                      const unsigned char* prelocs,
2646                                      size_t reloc_count,
2647                                      Output_section* output_section,
2648                                      bool needs_special_offset_handling,
2649                                      size_t local_symbol_count,
2650                                      const unsigned char* plocal_symbols,
2651                                      Relocatable_relocs* rr)
2652 {
2653   gold_assert(sh_type == elfcpp::SHT_REL);
2654
2655   typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_REL,
2656     Relocatable_size_for_reloc> Scan_relocatable_relocs;
2657
2658   gold::scan_relocatable_relocs<32, false, elfcpp::SHT_REL,
2659       Scan_relocatable_relocs>(
2660     symtab,
2661     layout,
2662     object,
2663     data_shndx,
2664     prelocs,
2665     reloc_count,
2666     output_section,
2667     needs_special_offset_handling,
2668     local_symbol_count,
2669     plocal_symbols,
2670     rr);
2671 }
2672
2673 // Relocate a section during a relocatable link.
2674
2675 void
2676 Target_i386::relocate_for_relocatable(
2677     const Relocate_info<32, false>* relinfo,
2678     unsigned int sh_type,
2679     const unsigned char* prelocs,
2680     size_t reloc_count,
2681     Output_section* output_section,
2682     off_t offset_in_output_section,
2683     const Relocatable_relocs* rr,
2684     unsigned char* view,
2685     elfcpp::Elf_types<32>::Elf_Addr view_address,
2686     section_size_type view_size,
2687     unsigned char* reloc_view,
2688     section_size_type reloc_view_size)
2689 {
2690   gold_assert(sh_type == elfcpp::SHT_REL);
2691
2692   gold::relocate_for_relocatable<32, false, elfcpp::SHT_REL>(
2693     relinfo,
2694     prelocs,
2695     reloc_count,
2696     output_section,
2697     offset_in_output_section,
2698     rr,
2699     view,
2700     view_address,
2701     view_size,
2702     reloc_view,
2703     reloc_view_size);
2704 }
2705
2706 // Return the value to use for a dynamic which requires special
2707 // treatment.  This is how we support equality comparisons of function
2708 // pointers across shared library boundaries, as described in the
2709 // processor specific ABI supplement.
2710
2711 uint64_t
2712 Target_i386::do_dynsym_value(const Symbol* gsym) const
2713 {
2714   gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
2715   return this->plt_section()->address() + gsym->plt_offset();
2716 }
2717
2718 // Return a string used to fill a code section with nops to take up
2719 // the specified length.
2720
2721 std::string
2722 Target_i386::do_code_fill(section_size_type length) const
2723 {
2724   if (length >= 16)
2725     {
2726       // Build a jmp instruction to skip over the bytes.
2727       unsigned char jmp[5];
2728       jmp[0] = 0xe9;
2729       elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
2730       return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
2731               + std::string(length - 5, '\0'));
2732     }
2733
2734   // Nop sequences of various lengths.
2735   const char nop1[1] = { 0x90 };                   // nop
2736   const char nop2[2] = { 0x66, 0x90 };             // xchg %ax %ax
2737   const char nop3[3] = { 0x8d, 0x76, 0x00 };       // leal 0(%esi),%esi
2738   const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00};  // leal 0(%esi,1),%esi
2739   const char nop5[5] = { 0x90, 0x8d, 0x74, 0x26,   // nop
2740                          0x00 };                   // leal 0(%esi,1),%esi
2741   const char nop6[6] = { 0x8d, 0xb6, 0x00, 0x00,   // leal 0L(%esi),%esi
2742                          0x00, 0x00 };
2743   const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00,   // leal 0L(%esi,1),%esi
2744                          0x00, 0x00, 0x00 };
2745   const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26,   // nop
2746                          0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
2747   const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc,   // movl %esi,%esi
2748                          0x27, 0x00, 0x00, 0x00,   // leal 0L(%edi,1),%edi
2749                          0x00 };
2750   const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
2751                            0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
2752                            0x00, 0x00 };
2753   const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
2754                            0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
2755                            0x00, 0x00, 0x00 };
2756   const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2757                            0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
2758                            0x00, 0x00, 0x00, 0x00 };
2759   const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2760                            0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
2761                            0x27, 0x00, 0x00, 0x00,
2762                            0x00 };
2763   const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2764                            0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
2765                            0xbc, 0x27, 0x00, 0x00,
2766                            0x00, 0x00 };
2767   const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
2768                            0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
2769                            0x90, 0x90, 0x90, 0x90,
2770                            0x90, 0x90, 0x90 };
2771
2772   const char* nops[16] = {
2773     NULL,
2774     nop1, nop2, nop3, nop4, nop5, nop6, nop7,
2775     nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
2776   };
2777
2778   return std::string(nops[length], length);
2779 }
2780
2781 // Return whether SYM should be treated as a call to a non-split
2782 // function.  We don't want that to be true of a call to a
2783 // get_pc_thunk function.
2784
2785 bool
2786 Target_i386::do_is_call_to_non_split(const Symbol* sym, unsigned int) const
2787 {
2788   return (sym->type() == elfcpp::STT_FUNC
2789           && !is_prefix_of("__i686.get_pc_thunk.", sym->name()));
2790 }
2791
2792 // FNOFFSET in section SHNDX in OBJECT is the start of a function
2793 // compiled with -fstack-split.  The function calls non-stack-split
2794 // code.  We have to change the function so that it always ensures
2795 // that it has enough stack space to run some random function.
2796
2797 void
2798 Target_i386::do_calls_non_split(Relobj* object, unsigned int shndx,
2799                                 section_offset_type fnoffset,
2800                                 section_size_type fnsize,
2801                                 unsigned char* view,
2802                                 section_size_type view_size,
2803                                 std::string* from,
2804                                 std::string* to) const
2805 {
2806   // The function starts with a comparison of the stack pointer and a
2807   // field in the TCB.  This is followed by a jump.
2808
2809   // cmp %gs:NN,%esp
2810   if (this->match_view(view, view_size, fnoffset, "\x65\x3b\x25", 3)
2811       && fnsize > 7)
2812     {
2813       // We will call __morestack if the carry flag is set after this
2814       // comparison.  We turn the comparison into an stc instruction
2815       // and some nops.
2816       view[fnoffset] = '\xf9';
2817       this->set_view_to_nop(view, view_size, fnoffset + 1, 6);
2818     }
2819   // lea NN(%esp),%ecx
2820   // lea NN(%esp),%edx
2821   else if ((this->match_view(view, view_size, fnoffset, "\x8d\x8c\x24", 3)
2822             || this->match_view(view, view_size, fnoffset, "\x8d\x94\x24", 3))
2823            && fnsize > 7)
2824     {
2825       // This is loading an offset from the stack pointer for a
2826       // comparison.  The offset is negative, so we decrease the
2827       // offset by the amount of space we need for the stack.  This
2828       // means we will avoid calling __morestack if there happens to
2829       // be plenty of space on the stack already.
2830       unsigned char* pval = view + fnoffset + 3;
2831       uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
2832       val -= parameters->options().split_stack_adjust_size();
2833       elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
2834     }
2835   else
2836     {
2837       if (!object->has_no_split_stack())
2838         object->error(_("failed to match split-stack sequence at "
2839                         "section %u offset %0zx"),
2840                       shndx, static_cast<size_t>(fnoffset));
2841       return;
2842     }
2843
2844   // We have to change the function so that it calls
2845   // __morestack_non_split instead of __morestack.  The former will
2846   // allocate additional stack space.
2847   *from = "__morestack";
2848   *to = "__morestack_non_split";
2849 }
2850
2851 // The selector for i386 object files.
2852
2853 class Target_selector_i386 : public Target_selector_freebsd
2854 {
2855 public:
2856   Target_selector_i386()
2857     : Target_selector_freebsd(elfcpp::EM_386, 32, false,
2858                               "elf32-i386", "elf32-i386-freebsd")
2859   { }
2860
2861   Target*
2862   do_instantiate_target()
2863   { return new Target_i386(); }
2864 };
2865
2866 Target_selector_i386 target_selector_i386;
2867
2868 } // End anonymous namespace.