* i386.cc (Target_i386::got_section): If -z now, make .got.plt a
[external/binutils.git] / gold / i386.cc
1 // i386.cc -- i386 target support for gold.
2
3 // Copyright 2006, 2007, 2008, 2009, 2010, 2011 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 "dwarf.h"
29 #include "parameters.h"
30 #include "reloc.h"
31 #include "i386.h"
32 #include "object.h"
33 #include "symtab.h"
34 #include "layout.h"
35 #include "output.h"
36 #include "copy-relocs.h"
37 #include "target.h"
38 #include "target-reloc.h"
39 #include "target-select.h"
40 #include "tls.h"
41 #include "freebsd.h"
42 #include "gc.h"
43
44 namespace
45 {
46
47 using namespace gold;
48
49 // A class to handle the PLT data.
50
51 class Output_data_plt_i386 : public Output_section_data
52 {
53  public:
54   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
55
56   Output_data_plt_i386(Layout*, Output_data_space*, Output_data_space*);
57
58   // Add an entry to the PLT.
59   void
60   add_entry(Symbol_table*, Layout*, Symbol* gsym);
61
62   // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
63   unsigned int
64   add_local_ifunc_entry(Symbol_table*, Layout*,
65                         Sized_relobj_file<32, false>* relobj,
66                         unsigned int local_sym_index);
67
68   // Return the .rel.plt section data.
69   Reloc_section*
70   rel_plt() const
71   { return this->rel_; }
72
73   // Return where the TLS_DESC relocations should go.
74   Reloc_section*
75   rel_tls_desc(Layout*);
76
77   // Return where the IRELATIVE relocations should go.
78   Reloc_section*
79   rel_irelative(Symbol_table*, Layout*);
80
81   // Return whether we created a section for IRELATIVE relocations.
82   bool
83   has_irelative_section() const
84   { return this->irelative_rel_ != NULL; }
85
86   // Return the number of PLT entries.
87   unsigned int
88   entry_count() const
89   { return this->count_ + this->irelative_count_; }
90
91   // Return the offset of the first non-reserved PLT entry.
92   static unsigned int
93   first_plt_entry_offset()
94   { return plt_entry_size; }
95
96   // Return the size of a PLT entry.
97   static unsigned int
98   get_plt_entry_size()
99   { return plt_entry_size; }
100
101   // Return the PLT address to use for a global symbol.
102   uint64_t
103   address_for_global(const Symbol*);
104
105   // Return the PLT address to use for a local symbol.
106   uint64_t
107   address_for_local(const Relobj*, unsigned int symndx);
108
109  protected:
110   void
111   do_adjust_output_section(Output_section* os);
112
113   // Write to a map file.
114   void
115   do_print_to_mapfile(Mapfile* mapfile) const
116   { mapfile->print_output_data(this, _("** PLT")); }
117
118  private:
119   // The size of an entry in the PLT.
120   static const int plt_entry_size = 16;
121
122   // The first entry in the PLT for an executable.
123   static const unsigned char exec_first_plt_entry[plt_entry_size];
124
125   // The first entry in the PLT for a shared object.
126   static const unsigned char dyn_first_plt_entry[plt_entry_size];
127
128   // Other entries in the PLT for an executable.
129   static const unsigned char exec_plt_entry[plt_entry_size];
130
131   // Other entries in the PLT for a shared object.
132   static const unsigned char dyn_plt_entry[plt_entry_size];
133
134   // The .eh_frame unwind information for the PLT.
135   static const int plt_eh_frame_cie_size = 16;
136   static const int plt_eh_frame_fde_size = 32;
137   static const unsigned char plt_eh_frame_cie[plt_eh_frame_cie_size];
138   static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
139
140   // Set the final size.
141   void
142   set_final_data_size()
143   {
144     this->set_data_size((this->count_ + this->irelative_count_ + 1)
145                         * plt_entry_size);
146   }
147
148   // Write out the PLT data.
149   void
150   do_write(Output_file*);
151
152   // We keep a list of global STT_GNU_IFUNC symbols, each with its
153   // offset in the GOT.
154   struct Global_ifunc
155   {
156     Symbol* sym;
157     unsigned int got_offset;
158   };
159
160   // We keep a list of local STT_GNU_IFUNC symbols, each with its
161   // offset in the GOT.
162   struct Local_ifunc
163   {
164     Sized_relobj_file<32, false>* object;
165     unsigned int local_sym_index;
166     unsigned int got_offset;
167   };
168
169   // The reloc section.
170   Reloc_section* rel_;
171   // The TLS_DESC relocations, if necessary.  These must follow the
172   // regular PLT relocs.
173   Reloc_section* tls_desc_rel_;
174   // The IRELATIVE relocations, if necessary.  These must follow the
175   // regular relocatoins and the TLS_DESC relocations.
176   Reloc_section* irelative_rel_;
177   // The .got.plt section.
178   Output_data_space* got_plt_;
179   // The part of the .got.plt section used for IRELATIVE relocs.
180   Output_data_space* got_irelative_;
181   // The number of PLT entries.
182   unsigned int count_;
183   // Number of PLT entries with R_386_IRELATIVE relocs.  These follow
184   // the regular PLT entries.
185   unsigned int irelative_count_;
186   // Global STT_GNU_IFUNC symbols.
187   std::vector<Global_ifunc> global_ifuncs_;
188   // Local STT_GNU_IFUNC symbols.
189   std::vector<Local_ifunc> local_ifuncs_;
190 };
191
192 // The i386 target class.
193 // TLS info comes from
194 //   http://people.redhat.com/drepper/tls.pdf
195 //   http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
196
197 class Target_i386 : public Sized_target<32, false>
198 {
199  public:
200   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
201
202   Target_i386()
203     : Sized_target<32, false>(&i386_info),
204       got_(NULL), plt_(NULL), got_plt_(NULL), got_irelative_(NULL),
205       got_tlsdesc_(NULL), global_offset_table_(NULL), rel_dyn_(NULL),
206       rel_irelative_(NULL), copy_relocs_(elfcpp::R_386_COPY), dynbss_(NULL),
207       got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
208   { }
209
210   // Process the relocations to determine unreferenced sections for 
211   // garbage collection.
212   void
213   gc_process_relocs(Symbol_table* symtab,
214                     Layout* layout,
215                     Sized_relobj_file<32, false>* object,
216                     unsigned int data_shndx,
217                     unsigned int sh_type,
218                     const unsigned char* prelocs,
219                     size_t reloc_count,
220                     Output_section* output_section,
221                     bool needs_special_offset_handling,
222                     size_t local_symbol_count,
223                     const unsigned char* plocal_symbols);
224
225   // Scan the relocations to look for symbol adjustments.
226   void
227   scan_relocs(Symbol_table* symtab,
228               Layout* layout,
229               Sized_relobj_file<32, false>* object,
230               unsigned int data_shndx,
231               unsigned int sh_type,
232               const unsigned char* prelocs,
233               size_t reloc_count,
234               Output_section* output_section,
235               bool needs_special_offset_handling,
236               size_t local_symbol_count,
237               const unsigned char* plocal_symbols);
238
239   // Finalize the sections.
240   void
241   do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
242
243   // Return the value to use for a dynamic which requires special
244   // treatment.
245   uint64_t
246   do_dynsym_value(const Symbol*) const;
247
248   // Relocate a section.
249   void
250   relocate_section(const Relocate_info<32, false>*,
251                    unsigned int sh_type,
252                    const unsigned char* prelocs,
253                    size_t reloc_count,
254                    Output_section* output_section,
255                    bool needs_special_offset_handling,
256                    unsigned char* view,
257                    elfcpp::Elf_types<32>::Elf_Addr view_address,
258                    section_size_type view_size,
259                    const Reloc_symbol_changes*);
260
261   // Scan the relocs during a relocatable link.
262   void
263   scan_relocatable_relocs(Symbol_table* symtab,
264                           Layout* layout,
265                           Sized_relobj_file<32, false>* object,
266                           unsigned int data_shndx,
267                           unsigned int sh_type,
268                           const unsigned char* prelocs,
269                           size_t reloc_count,
270                           Output_section* output_section,
271                           bool needs_special_offset_handling,
272                           size_t local_symbol_count,
273                           const unsigned char* plocal_symbols,
274                           Relocatable_relocs*);
275
276   // Relocate a section during a relocatable link.
277   void
278   relocate_for_relocatable(const Relocate_info<32, false>*,
279                            unsigned int sh_type,
280                            const unsigned char* prelocs,
281                            size_t reloc_count,
282                            Output_section* output_section,
283                            off_t offset_in_output_section,
284                            const Relocatable_relocs*,
285                            unsigned char* view,
286                            elfcpp::Elf_types<32>::Elf_Addr view_address,
287                            section_size_type view_size,
288                            unsigned char* reloc_view,
289                            section_size_type reloc_view_size);
290
291   // Return a string used to fill a code section with nops.
292   std::string
293   do_code_fill(section_size_type length) const;
294
295   // Return whether SYM is defined by the ABI.
296   bool
297   do_is_defined_by_abi(const Symbol* sym) const
298   { return strcmp(sym->name(), "___tls_get_addr") == 0; }
299
300   // Return whether a symbol name implies a local label.  The UnixWare
301   // 2.1 cc generates temporary symbols that start with .X, so we
302   // recognize them here.  FIXME: do other SVR4 compilers also use .X?.
303   // If so, we should move the .X recognition into
304   // Target::do_is_local_label_name.
305   bool
306   do_is_local_label_name(const char* name) const
307   {
308     if (name[0] == '.' && name[1] == 'X')
309       return true;
310     return Target::do_is_local_label_name(name);
311   }
312
313   // Return the PLT address to use for a global symbol.
314   uint64_t
315   do_plt_address_for_global(const Symbol* gsym) const
316   { return this->plt_section()->address_for_global(gsym); }
317
318   uint64_t
319   do_plt_address_for_local(const Relobj* relobj, unsigned int symndx) const
320   { return this->plt_section()->address_for_local(relobj, symndx); }
321
322   // We can tell whether we take the address of a function.
323   inline bool
324   do_can_check_for_function_pointers() const
325   { return true; }
326
327   // Return the base for a DW_EH_PE_datarel encoding.
328   uint64_t
329   do_ehframe_datarel_base() const;
330
331   // Return whether SYM is call to a non-split function.
332   bool
333   do_is_call_to_non_split(const Symbol* sym, unsigned int) const;
334
335   // Adjust -fsplit-stack code which calls non-split-stack code.
336   void
337   do_calls_non_split(Relobj* object, unsigned int shndx,
338                      section_offset_type fnoffset, section_size_type fnsize,
339                      unsigned char* view, section_size_type view_size,
340                      std::string* from, std::string* to) const;
341
342   // Return the size of the GOT section.
343   section_size_type
344   got_size() const
345   {
346     gold_assert(this->got_ != NULL);
347     return this->got_->data_size();
348   }
349
350   // Return the number of entries in the GOT.
351   unsigned int
352   got_entry_count() const
353   {
354     if (this->got_ == NULL)
355       return 0;
356     return this->got_size() / 4;
357   }
358
359   // Return the number of entries in the PLT.
360   unsigned int
361   plt_entry_count() const;
362
363   // Return the offset of the first non-reserved PLT entry.
364   unsigned int
365   first_plt_entry_offset() const;
366
367   // Return the size of each PLT entry.
368   unsigned int
369   plt_entry_size() const;
370
371  private:
372   // The class which scans relocations.
373   struct Scan
374   {
375     static inline int
376
377     get_reference_flags(unsigned int r_type);
378
379     inline void
380     local(Symbol_table* symtab, Layout* layout, Target_i386* target,
381           Sized_relobj_file<32, false>* object,
382           unsigned int data_shndx,
383           Output_section* output_section,
384           const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
385           const elfcpp::Sym<32, false>& lsym);
386
387     inline void
388     global(Symbol_table* symtab, Layout* layout, Target_i386* target,
389            Sized_relobj_file<32, false>* object,
390            unsigned int data_shndx,
391            Output_section* output_section,
392            const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
393            Symbol* gsym);
394
395     inline bool
396     local_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
397                                         Target_i386* target,
398                                         Sized_relobj_file<32, false>* object,
399                                         unsigned int data_shndx,
400                                         Output_section* output_section,
401                                         const elfcpp::Rel<32, false>& reloc,
402                                         unsigned int r_type,
403                                         const elfcpp::Sym<32, false>& lsym);
404
405     inline bool
406     global_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
407                                          Target_i386* target,
408                                          Sized_relobj_file<32, false>* object,
409                                          unsigned int data_shndx,
410                                          Output_section* output_section,
411                                          const elfcpp::Rel<32, false>& reloc,
412                                          unsigned int r_type,
413                                          Symbol* gsym);
414
415     inline bool
416     possible_function_pointer_reloc(unsigned int r_type);
417
418     bool
419     reloc_needs_plt_for_ifunc(Sized_relobj_file<32, false>*,
420                               unsigned int r_type);
421
422     static void
423     unsupported_reloc_local(Sized_relobj_file<32, false>*, unsigned int r_type);
424
425     static void
426     unsupported_reloc_global(Sized_relobj_file<32, false>*, unsigned int r_type,
427                              Symbol*);
428   };
429
430   // The class which implements relocation.
431   class Relocate
432   {
433    public:
434     Relocate()
435       : skip_call_tls_get_addr_(false),
436         local_dynamic_type_(LOCAL_DYNAMIC_NONE)
437     { }
438
439     ~Relocate()
440     {
441       if (this->skip_call_tls_get_addr_)
442         {
443           // FIXME: This needs to specify the location somehow.
444           gold_error(_("missing expected TLS relocation"));
445         }
446     }
447
448     // Return whether the static relocation needs to be applied.
449     inline bool
450     should_apply_static_reloc(const Sized_symbol<32>* gsym,
451                               unsigned int r_type,
452                               bool is_32bit,
453                               Output_section* output_section);
454
455     // Do a relocation.  Return false if the caller should not issue
456     // any warnings about this relocation.
457     inline bool
458     relocate(const Relocate_info<32, false>*, Target_i386*, Output_section*,
459              size_t relnum, const elfcpp::Rel<32, false>&,
460              unsigned int r_type, const Sized_symbol<32>*,
461              const Symbol_value<32>*,
462              unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
463              section_size_type);
464
465    private:
466     // Do a TLS relocation.
467     inline void
468     relocate_tls(const Relocate_info<32, false>*, Target_i386* target,
469                  size_t relnum, const elfcpp::Rel<32, false>&,
470                  unsigned int r_type, const Sized_symbol<32>*,
471                  const Symbol_value<32>*,
472                  unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
473                  section_size_type);
474
475     // Do a TLS General-Dynamic to Initial-Exec transition.
476     inline void
477     tls_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
478                  Output_segment* tls_segment,
479                  const elfcpp::Rel<32, false>&, unsigned int r_type,
480                  elfcpp::Elf_types<32>::Elf_Addr value,
481                  unsigned char* view,
482                  section_size_type view_size);
483
484     // Do a TLS General-Dynamic to Local-Exec transition.
485     inline void
486     tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
487                  Output_segment* tls_segment,
488                  const elfcpp::Rel<32, false>&, unsigned int r_type,
489                  elfcpp::Elf_types<32>::Elf_Addr value,
490                  unsigned char* view,
491                  section_size_type view_size);
492
493     // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
494     // transition.
495     inline void
496     tls_desc_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
497                       Output_segment* tls_segment,
498                       const elfcpp::Rel<32, false>&, unsigned int r_type,
499                       elfcpp::Elf_types<32>::Elf_Addr value,
500                       unsigned char* view,
501                       section_size_type view_size);
502
503     // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
504     // transition.
505     inline void
506     tls_desc_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
507                       Output_segment* tls_segment,
508                       const elfcpp::Rel<32, false>&, unsigned int r_type,
509                       elfcpp::Elf_types<32>::Elf_Addr value,
510                       unsigned char* view,
511                       section_size_type view_size);
512
513     // Do a TLS Local-Dynamic to Local-Exec transition.
514     inline void
515     tls_ld_to_le(const Relocate_info<32, false>*, size_t relnum,
516                  Output_segment* tls_segment,
517                  const elfcpp::Rel<32, false>&, unsigned int r_type,
518                  elfcpp::Elf_types<32>::Elf_Addr value,
519                  unsigned char* view,
520                  section_size_type view_size);
521
522     // Do a TLS Initial-Exec to Local-Exec transition.
523     static inline void
524     tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum,
525                  Output_segment* tls_segment,
526                  const elfcpp::Rel<32, false>&, unsigned int r_type,
527                  elfcpp::Elf_types<32>::Elf_Addr value,
528                  unsigned char* view,
529                  section_size_type view_size);
530
531     // We need to keep track of which type of local dynamic relocation
532     // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
533     enum Local_dynamic_type
534     {
535       LOCAL_DYNAMIC_NONE,
536       LOCAL_DYNAMIC_SUN,
537       LOCAL_DYNAMIC_GNU
538     };
539
540     // This is set if we should skip the next reloc, which should be a
541     // PLT32 reloc against ___tls_get_addr.
542     bool skip_call_tls_get_addr_;
543     // The type of local dynamic relocation we have seen in the section
544     // being relocated, if any.
545     Local_dynamic_type local_dynamic_type_;
546   };
547
548   // A class which returns the size required for a relocation type,
549   // used while scanning relocs during a relocatable link.
550   class Relocatable_size_for_reloc
551   {
552    public:
553     unsigned int
554     get_size_for_reloc(unsigned int, Relobj*);
555   };
556
557   // Adjust TLS relocation type based on the options and whether this
558   // is a local symbol.
559   static tls::Tls_optimization
560   optimize_tls_reloc(bool is_final, int r_type);
561
562   // Get the GOT section, creating it if necessary.
563   Output_data_got<32, false>*
564   got_section(Symbol_table*, Layout*);
565
566   // Get the GOT PLT section.
567   Output_data_space*
568   got_plt_section() const
569   {
570     gold_assert(this->got_plt_ != NULL);
571     return this->got_plt_;
572   }
573
574   // Get the GOT section for TLSDESC entries.
575   Output_data_got<32, false>*
576   got_tlsdesc_section() const
577   {
578     gold_assert(this->got_tlsdesc_ != NULL);
579     return this->got_tlsdesc_;
580   }
581
582   // Create the PLT section.
583   void
584   make_plt_section(Symbol_table* symtab, Layout* layout);
585
586   // Create a PLT entry for a global symbol.
587   void
588   make_plt_entry(Symbol_table*, Layout*, Symbol*);
589
590   // Create a PLT entry for a local STT_GNU_IFUNC symbol.
591   void
592   make_local_ifunc_plt_entry(Symbol_table*, Layout*,
593                              Sized_relobj_file<32, false>* relobj,
594                              unsigned int local_sym_index);
595
596   // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
597   void
598   define_tls_base_symbol(Symbol_table*, Layout*);
599
600   // Create a GOT entry for the TLS module index.
601   unsigned int
602   got_mod_index_entry(Symbol_table* symtab, Layout* layout,
603                       Sized_relobj_file<32, false>* object);
604
605   // Get the PLT section.
606   Output_data_plt_i386*
607   plt_section() const
608   {
609     gold_assert(this->plt_ != NULL);
610     return this->plt_;
611   }
612
613   // Get the dynamic reloc section, creating it if necessary.
614   Reloc_section*
615   rel_dyn_section(Layout*);
616
617   // Get the section to use for TLS_DESC relocations.
618   Reloc_section*
619   rel_tls_desc_section(Layout*) const;
620
621   // Get the section to use for IRELATIVE relocations.
622   Reloc_section*
623   rel_irelative_section(Layout*);
624
625   // Add a potential copy relocation.
626   void
627   copy_reloc(Symbol_table* symtab, Layout* layout,
628              Sized_relobj_file<32, false>* object,
629              unsigned int shndx, Output_section* output_section,
630              Symbol* sym, const elfcpp::Rel<32, false>& reloc)
631   {
632     this->copy_relocs_.copy_reloc(symtab, layout,
633                                   symtab->get_sized_symbol<32>(sym),
634                                   object, shndx, output_section, reloc,
635                                   this->rel_dyn_section(layout));
636   }
637
638   // Information about this specific target which we pass to the
639   // general Target structure.
640   static const Target::Target_info i386_info;
641
642   // The types of GOT entries needed for this platform.
643   // These values are exposed to the ABI in an incremental link.
644   // Do not renumber existing values without changing the version
645   // number of the .gnu_incremental_inputs section.
646   enum Got_type
647   {
648     GOT_TYPE_STANDARD = 0,      // GOT entry for a regular symbol
649     GOT_TYPE_TLS_NOFFSET = 1,   // GOT entry for negative TLS offset
650     GOT_TYPE_TLS_OFFSET = 2,    // GOT entry for positive TLS offset
651     GOT_TYPE_TLS_PAIR = 3,      // GOT entry for TLS module/offset pair
652     GOT_TYPE_TLS_DESC = 4       // GOT entry for TLS_DESC pair
653   };
654
655   // The GOT section.
656   Output_data_got<32, false>* got_;
657   // The PLT section.
658   Output_data_plt_i386* plt_;
659   // The GOT PLT section.
660   Output_data_space* got_plt_;
661   // The GOT section for IRELATIVE relocations.
662   Output_data_space* got_irelative_;
663   // The GOT section for TLSDESC relocations.
664   Output_data_got<32, false>* got_tlsdesc_;
665   // The _GLOBAL_OFFSET_TABLE_ symbol.
666   Symbol* global_offset_table_;
667   // The dynamic reloc section.
668   Reloc_section* rel_dyn_;
669   // The section to use for IRELATIVE relocs.
670   Reloc_section* rel_irelative_;
671   // Relocs saved to avoid a COPY reloc.
672   Copy_relocs<elfcpp::SHT_REL, 32, false> copy_relocs_;
673   // Space for variables copied with a COPY reloc.
674   Output_data_space* dynbss_;
675   // Offset of the GOT entry for the TLS module index.
676   unsigned int got_mod_index_offset_;
677   // True if the _TLS_MODULE_BASE_ symbol has been defined.
678   bool tls_base_symbol_defined_;
679 };
680
681 const Target::Target_info Target_i386::i386_info =
682 {
683   32,                   // size
684   false,                // is_big_endian
685   elfcpp::EM_386,       // machine_code
686   false,                // has_make_symbol
687   false,                // has_resolve
688   true,                 // has_code_fill
689   true,                 // is_default_stack_executable
690   true,                 // can_icf_inline_merge_sections
691   '\0',                 // wrap_char
692   "/usr/lib/libc.so.1", // dynamic_linker
693   0x08048000,           // default_text_segment_address
694   0x1000,               // abi_pagesize (overridable by -z max-page-size)
695   0x1000,               // common_pagesize (overridable by -z common-page-size)
696   elfcpp::SHN_UNDEF,    // small_common_shndx
697   elfcpp::SHN_UNDEF,    // large_common_shndx
698   0,                    // small_common_section_flags
699   0,                    // large_common_section_flags
700   NULL,                 // attributes_section
701   NULL                  // attributes_vendor
702 };
703
704 // Get the GOT section, creating it if necessary.
705
706 Output_data_got<32, false>*
707 Target_i386::got_section(Symbol_table* symtab, Layout* layout)
708 {
709   if (this->got_ == NULL)
710     {
711       gold_assert(symtab != NULL && layout != NULL);
712
713       this->got_ = new Output_data_got<32, false>();
714
715       // When using -z now, we can treat .got.plt as a relro section.
716       // Without -z now, it is modified after program startup by lazy
717       // PLT relocations.
718       bool is_got_plt_relro = parameters->options().now();
719       Output_section_order got_order = (is_got_plt_relro
720                                         ? ORDER_RELRO
721                                         : ORDER_RELRO_LAST);
722       Output_section_order got_plt_order = (is_got_plt_relro
723                                             ? ORDER_RELRO
724                                             : ORDER_NON_RELRO_FIRST);
725
726       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
727                                       (elfcpp::SHF_ALLOC
728                                        | elfcpp::SHF_WRITE),
729                                       this->got_, got_order, true);
730
731       this->got_plt_ = new Output_data_space(4, "** GOT PLT");
732       layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
733                                       (elfcpp::SHF_ALLOC
734                                        | elfcpp::SHF_WRITE),
735                                       this->got_plt_, got_plt_order,
736                                       is_got_plt_relro);
737
738       // The first three entries are reserved.
739       this->got_plt_->set_current_data_size(3 * 4);
740
741       if (!is_got_plt_relro)
742         {
743           // Those bytes can go into the relro segment.
744           layout->increase_relro(3 * 4);
745         }
746
747       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
748       this->global_offset_table_ =
749         symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
750                                       Symbol_table::PREDEFINED,
751                                       this->got_plt_,
752                                       0, 0, elfcpp::STT_OBJECT,
753                                       elfcpp::STB_LOCAL,
754                                       elfcpp::STV_HIDDEN, 0,
755                                       false, false);
756
757       // If there are any IRELATIVE relocations, they get GOT entries
758       // in .got.plt after the jump slot relocations.
759       this->got_irelative_ = new Output_data_space(4, "** GOT IRELATIVE PLT");
760       layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
761                                       (elfcpp::SHF_ALLOC
762                                        | elfcpp::SHF_WRITE),
763                                       this->got_irelative_,
764                                       got_plt_order, is_got_plt_relro);
765
766       // If there are any TLSDESC relocations, they get GOT entries in
767       // .got.plt after the jump slot entries.
768       this->got_tlsdesc_ = new Output_data_got<32, false>();
769       layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
770                                       (elfcpp::SHF_ALLOC
771                                        | elfcpp::SHF_WRITE),
772                                       this->got_tlsdesc_,
773                                       got_plt_order, is_got_plt_relro);
774     }
775
776   return this->got_;
777 }
778
779 // Get the dynamic reloc section, creating it if necessary.
780
781 Target_i386::Reloc_section*
782 Target_i386::rel_dyn_section(Layout* layout)
783 {
784   if (this->rel_dyn_ == NULL)
785     {
786       gold_assert(layout != NULL);
787       this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
788       layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
789                                       elfcpp::SHF_ALLOC, this->rel_dyn_,
790                                       ORDER_DYNAMIC_RELOCS, false);
791     }
792   return this->rel_dyn_;
793 }
794
795 // Get the section to use for IRELATIVE relocs, creating it if
796 // necessary.  These go in .rel.dyn, but only after all other dynamic
797 // relocations.  They need to follow the other dynamic relocations so
798 // that they can refer to global variables initialized by those
799 // relocs.
800
801 Target_i386::Reloc_section*
802 Target_i386::rel_irelative_section(Layout* layout)
803 {
804   if (this->rel_irelative_ == NULL)
805     {
806       // Make sure we have already create the dynamic reloc section.
807       this->rel_dyn_section(layout);
808       this->rel_irelative_ = new Reloc_section(false);
809       layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
810                                       elfcpp::SHF_ALLOC, this->rel_irelative_,
811                                       ORDER_DYNAMIC_RELOCS, false);
812       gold_assert(this->rel_dyn_->output_section()
813                   == this->rel_irelative_->output_section());
814     }
815   return this->rel_irelative_;
816 }
817
818 // Create the PLT section.  The ordinary .got section is an argument,
819 // since we need to refer to the start.  We also create our own .got
820 // section just for PLT entries.
821
822 Output_data_plt_i386::Output_data_plt_i386(Layout* layout,
823                                            Output_data_space* got_plt,
824                                            Output_data_space* got_irelative)
825   : Output_section_data(16), tls_desc_rel_(NULL), irelative_rel_(NULL),
826     got_plt_(got_plt), got_irelative_(got_irelative), count_(0),
827     irelative_count_(0), global_ifuncs_(), local_ifuncs_()
828 {
829   this->rel_ = new Reloc_section(false);
830   layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
831                                   elfcpp::SHF_ALLOC, this->rel_,
832                                   ORDER_DYNAMIC_PLT_RELOCS, false);
833
834   // Add unwind information if requested.
835   if (parameters->options().ld_generated_unwind_info())
836     layout->add_eh_frame_for_plt(this, plt_eh_frame_cie, plt_eh_frame_cie_size,
837                                  plt_eh_frame_fde, plt_eh_frame_fde_size);
838 }
839
840 void
841 Output_data_plt_i386::do_adjust_output_section(Output_section* os)
842 {
843   // UnixWare sets the entsize of .plt to 4, and so does the old GNU
844   // linker, and so do we.
845   os->set_entsize(4);
846 }
847
848 // Add an entry to the PLT.
849
850 void
851 Output_data_plt_i386::add_entry(Symbol_table* symtab, Layout* layout,
852                                 Symbol* gsym)
853 {
854   gold_assert(!gsym->has_plt_offset());
855
856   // Every PLT entry needs a reloc.
857   if (gsym->type() == elfcpp::STT_GNU_IFUNC
858       && gsym->can_use_relative_reloc(false))
859     {
860       gsym->set_plt_offset(this->irelative_count_ * plt_entry_size);
861       ++this->irelative_count_;
862       section_offset_type got_offset =
863         this->got_irelative_->current_data_size();
864       this->got_irelative_->set_current_data_size(got_offset + 4);
865       Reloc_section* rel = this->rel_irelative(symtab, layout);
866       rel->add_symbolless_global_addend(gsym, elfcpp::R_386_IRELATIVE,
867                                         this->got_irelative_, got_offset);
868       struct Global_ifunc gi;
869       gi.sym = gsym;
870       gi.got_offset = got_offset;
871       this->global_ifuncs_.push_back(gi);
872     }
873   else
874     {
875       // When setting the PLT offset we skip the initial reserved PLT
876       // entry.
877       gsym->set_plt_offset((this->count_ + 1) * plt_entry_size);
878
879       ++this->count_;
880
881       section_offset_type got_offset = this->got_plt_->current_data_size();
882
883       // Every PLT entry needs a GOT entry which points back to the
884       // PLT entry (this will be changed by the dynamic linker,
885       // normally lazily when the function is called).
886       this->got_plt_->set_current_data_size(got_offset + 4);
887
888       gsym->set_needs_dynsym_entry();
889       this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_,
890                              got_offset);
891     }
892
893   // Note that we don't need to save the symbol.  The contents of the
894   // PLT are independent of which symbols are used.  The symbols only
895   // appear in the relocations.
896 }
897
898 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.  Return
899 // the PLT offset.
900
901 unsigned int
902 Output_data_plt_i386::add_local_ifunc_entry(
903     Symbol_table* symtab,
904     Layout* layout,
905     Sized_relobj_file<32, false>* relobj,
906     unsigned int local_sym_index)
907 {
908   unsigned int plt_offset = this->irelative_count_ * plt_entry_size;
909   ++this->irelative_count_;
910
911   section_offset_type got_offset = this->got_irelative_->current_data_size();
912
913   // Every PLT entry needs a GOT entry which points back to the PLT
914   // entry.
915   this->got_irelative_->set_current_data_size(got_offset + 4);
916
917   // Every PLT entry needs a reloc.
918   Reloc_section* rel = this->rel_irelative(symtab, layout);
919   rel->add_symbolless_local_addend(relobj, local_sym_index,
920                                    elfcpp::R_386_IRELATIVE,
921                                    this->got_irelative_, got_offset);
922
923   struct Local_ifunc li;
924   li.object = relobj;
925   li.local_sym_index = local_sym_index;
926   li.got_offset = got_offset;
927   this->local_ifuncs_.push_back(li);
928
929   return plt_offset;
930 }
931
932 // Return where the TLS_DESC relocations should go, creating it if
933 // necessary. These follow the JUMP_SLOT relocations.
934
935 Output_data_plt_i386::Reloc_section*
936 Output_data_plt_i386::rel_tls_desc(Layout* layout)
937 {
938   if (this->tls_desc_rel_ == NULL)
939     {
940       this->tls_desc_rel_ = new Reloc_section(false);
941       layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
942                                       elfcpp::SHF_ALLOC, this->tls_desc_rel_,
943                                       ORDER_DYNAMIC_PLT_RELOCS, false);
944       gold_assert(this->tls_desc_rel_->output_section()
945                   == this->rel_->output_section());
946     }
947   return this->tls_desc_rel_;
948 }
949
950 // Return where the IRELATIVE relocations should go in the PLT.  These
951 // follow the JUMP_SLOT and TLS_DESC relocations.
952
953 Output_data_plt_i386::Reloc_section*
954 Output_data_plt_i386::rel_irelative(Symbol_table* symtab, Layout* layout)
955 {
956   if (this->irelative_rel_ == NULL)
957     {
958       // Make sure we have a place for the TLS_DESC relocations, in
959       // case we see any later on.
960       this->rel_tls_desc(layout);
961       this->irelative_rel_ = new Reloc_section(false);
962       layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
963                                       elfcpp::SHF_ALLOC, this->irelative_rel_,
964                                       ORDER_DYNAMIC_PLT_RELOCS, false);
965       gold_assert(this->irelative_rel_->output_section()
966                   == this->rel_->output_section());
967
968       if (parameters->doing_static_link())
969         {
970           // A statically linked executable will only have a .rel.plt
971           // section to hold R_386_IRELATIVE relocs for STT_GNU_IFUNC
972           // symbols.  The library will use these symbols to locate
973           // the IRELATIVE relocs at program startup time.
974           symtab->define_in_output_data("__rel_iplt_start", NULL,
975                                         Symbol_table::PREDEFINED,
976                                         this->irelative_rel_, 0, 0,
977                                         elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
978                                         elfcpp::STV_HIDDEN, 0, false, true);
979           symtab->define_in_output_data("__rel_iplt_end", NULL,
980                                         Symbol_table::PREDEFINED,
981                                         this->irelative_rel_, 0, 0,
982                                         elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
983                                         elfcpp::STV_HIDDEN, 0, true, true);
984         }
985     }
986   return this->irelative_rel_;
987 }
988
989 // Return the PLT address to use for a global symbol.
990
991 uint64_t
992 Output_data_plt_i386::address_for_global(const Symbol* gsym)
993 {
994   uint64_t offset = 0;
995   if (gsym->type() == elfcpp::STT_GNU_IFUNC
996       && gsym->can_use_relative_reloc(false))
997     offset = (this->count_ + 1) * plt_entry_size;
998   return this->address() + offset;
999 }
1000
1001 // Return the PLT address to use for a local symbol.  These are always
1002 // IRELATIVE relocs.
1003
1004 uint64_t
1005 Output_data_plt_i386::address_for_local(const Relobj*, unsigned int)
1006 {
1007   return this->address() + (this->count_ + 1) * plt_entry_size;
1008 }
1009
1010 // The first entry in the PLT for an executable.
1011
1012 const unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] =
1013 {
1014   0xff, 0x35,   // pushl contents of memory address
1015   0, 0, 0, 0,   // replaced with address of .got + 4
1016   0xff, 0x25,   // jmp indirect
1017   0, 0, 0, 0,   // replaced with address of .got + 8
1018   0, 0, 0, 0    // unused
1019 };
1020
1021 // The first entry in the PLT for a shared object.
1022
1023 const unsigned char Output_data_plt_i386::dyn_first_plt_entry[plt_entry_size] =
1024 {
1025   0xff, 0xb3, 4, 0, 0, 0,       // pushl 4(%ebx)
1026   0xff, 0xa3, 8, 0, 0, 0,       // jmp *8(%ebx)
1027   0, 0, 0, 0                    // unused
1028 };
1029
1030 // Subsequent entries in the PLT for an executable.
1031
1032 const unsigned char Output_data_plt_i386::exec_plt_entry[plt_entry_size] =
1033 {
1034   0xff, 0x25,   // jmp indirect
1035   0, 0, 0, 0,   // replaced with address of symbol in .got
1036   0x68,         // pushl immediate
1037   0, 0, 0, 0,   // replaced with offset into relocation table
1038   0xe9,         // jmp relative
1039   0, 0, 0, 0    // replaced with offset to start of .plt
1040 };
1041
1042 // Subsequent entries in the PLT for a shared object.
1043
1044 const unsigned char Output_data_plt_i386::dyn_plt_entry[plt_entry_size] =
1045 {
1046   0xff, 0xa3,   // jmp *offset(%ebx)
1047   0, 0, 0, 0,   // replaced with offset of symbol in .got
1048   0x68,         // pushl immediate
1049   0, 0, 0, 0,   // replaced with offset into relocation table
1050   0xe9,         // jmp relative
1051   0, 0, 0, 0    // replaced with offset to start of .plt
1052 };
1053
1054 // The .eh_frame unwind information for the PLT.
1055
1056 const unsigned char
1057 Output_data_plt_i386::plt_eh_frame_cie[plt_eh_frame_cie_size] =
1058 {
1059   1,                            // CIE version.
1060   'z',                          // Augmentation: augmentation size included.
1061   'R',                          // Augmentation: FDE encoding included.
1062   '\0',                         // End of augmentation string.
1063   1,                            // Code alignment factor.
1064   0x7c,                         // Data alignment factor.
1065   8,                            // Return address column.
1066   1,                            // Augmentation size.
1067   (elfcpp::DW_EH_PE_pcrel       // FDE encoding.
1068    | elfcpp::DW_EH_PE_sdata4),
1069   elfcpp::DW_CFA_def_cfa, 4, 4, // DW_CFA_def_cfa: r4 (esp) ofs 4.
1070   elfcpp::DW_CFA_offset + 8, 1, // DW_CFA_offset: r8 (eip) at cfa-4.
1071   elfcpp::DW_CFA_nop,           // Align to 16 bytes.
1072   elfcpp::DW_CFA_nop
1073 };
1074
1075 const unsigned char
1076 Output_data_plt_i386::plt_eh_frame_fde[plt_eh_frame_fde_size] =
1077 {
1078   0, 0, 0, 0,                           // Replaced with offset to .plt.
1079   0, 0, 0, 0,                           // Replaced with size of .plt.
1080   0,                                    // Augmentation size.
1081   elfcpp::DW_CFA_def_cfa_offset, 8,     // DW_CFA_def_cfa_offset: 8.
1082   elfcpp::DW_CFA_advance_loc + 6,       // Advance 6 to __PLT__ + 6.
1083   elfcpp::DW_CFA_def_cfa_offset, 12,    // DW_CFA_def_cfa_offset: 12.
1084   elfcpp::DW_CFA_advance_loc + 10,      // Advance 10 to __PLT__ + 16.
1085   elfcpp::DW_CFA_def_cfa_expression,    // DW_CFA_def_cfa_expression.
1086   11,                                   // Block length.
1087   elfcpp::DW_OP_breg4, 4,               // Push %esp + 4.
1088   elfcpp::DW_OP_breg8, 0,               // Push %eip.
1089   elfcpp::DW_OP_lit15,                  // Push 0xf.
1090   elfcpp::DW_OP_and,                    // & (%eip & 0xf).
1091   elfcpp::DW_OP_lit11,                  // Push 0xb.
1092   elfcpp::DW_OP_ge,                     // >= ((%eip & 0xf) >= 0xb)
1093   elfcpp::DW_OP_lit2,                   // Push 2.
1094   elfcpp::DW_OP_shl,                    // << (((%eip & 0xf) >= 0xb) << 2)
1095   elfcpp::DW_OP_plus,                   // + ((((%eip&0xf)>=0xb)<<2)+%esp+4
1096   elfcpp::DW_CFA_nop,                   // Align to 32 bytes.
1097   elfcpp::DW_CFA_nop,
1098   elfcpp::DW_CFA_nop,
1099   elfcpp::DW_CFA_nop
1100 };
1101
1102 // Write out the PLT.  This uses the hand-coded instructions above,
1103 // and adjusts them as needed.  This is all specified by the i386 ELF
1104 // Processor Supplement.
1105
1106 void
1107 Output_data_plt_i386::do_write(Output_file* of)
1108 {
1109   const off_t offset = this->offset();
1110   const section_size_type oview_size =
1111     convert_to_section_size_type(this->data_size());
1112   unsigned char* const oview = of->get_output_view(offset, oview_size);
1113
1114   const off_t got_file_offset = this->got_plt_->offset();
1115   gold_assert(parameters->incremental_update()
1116               || (got_file_offset + this->got_plt_->data_size()
1117                   == this->got_irelative_->offset()));
1118   const section_size_type got_size =
1119     convert_to_section_size_type(this->got_plt_->data_size()
1120                                  + this->got_irelative_->data_size());
1121   unsigned char* const got_view = of->get_output_view(got_file_offset,
1122                                                       got_size);
1123
1124   unsigned char* pov = oview;
1125
1126   elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address();
1127   elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address();
1128
1129   if (parameters->options().output_is_position_independent())
1130     memcpy(pov, dyn_first_plt_entry, plt_entry_size);
1131   else
1132     {
1133       memcpy(pov, exec_first_plt_entry, plt_entry_size);
1134       elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
1135       elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
1136     }
1137   pov += plt_entry_size;
1138
1139   unsigned char* got_pov = got_view;
1140
1141   memset(got_pov, 0, 12);
1142   got_pov += 12;
1143
1144   const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
1145
1146   unsigned int plt_offset = plt_entry_size;
1147   unsigned int plt_rel_offset = 0;
1148   unsigned int got_offset = 12;
1149   const unsigned int count = this->count_ + this->irelative_count_;
1150   for (unsigned int i = 0;
1151        i < count;
1152        ++i,
1153          pov += plt_entry_size,
1154          got_pov += 4,
1155          plt_offset += plt_entry_size,
1156          plt_rel_offset += rel_size,
1157          got_offset += 4)
1158     {
1159       // Set and adjust the PLT entry itself.
1160
1161       if (parameters->options().output_is_position_independent())
1162         {
1163           memcpy(pov, dyn_plt_entry, plt_entry_size);
1164           elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
1165         }
1166       else
1167         {
1168           memcpy(pov, exec_plt_entry, plt_entry_size);
1169           elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1170                                                       (got_address
1171                                                        + got_offset));
1172         }
1173
1174       elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
1175       elfcpp::Swap<32, false>::writeval(pov + 12,
1176                                         - (plt_offset + plt_entry_size));
1177
1178       // Set the entry in the GOT.
1179       elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6);
1180     }
1181
1182   // If any STT_GNU_IFUNC symbols have PLT entries, we need to change
1183   // the GOT to point to the actual symbol value, rather than point to
1184   // the PLT entry.  That will let the dynamic linker call the right
1185   // function when resolving IRELATIVE relocations.
1186   unsigned char* got_irelative_view = got_view + this->got_plt_->data_size();
1187   for (std::vector<Global_ifunc>::const_iterator p =
1188          this->global_ifuncs_.begin();
1189        p != this->global_ifuncs_.end();
1190        ++p)
1191     {
1192       const Sized_symbol<32>* ssym =
1193         static_cast<const Sized_symbol<32>*>(p->sym);
1194       elfcpp::Swap<32, false>::writeval(got_irelative_view + p->got_offset,
1195                                         ssym->value());
1196     }
1197
1198   for (std::vector<Local_ifunc>::const_iterator p =
1199          this->local_ifuncs_.begin();
1200        p != this->local_ifuncs_.end();
1201        ++p)
1202     {
1203       const Symbol_value<32>* psymval =
1204         p->object->local_symbol(p->local_sym_index);
1205       elfcpp::Swap<32, false>::writeval(got_irelative_view + p->got_offset,
1206                                         psymval->value(p->object, 0));
1207     }
1208
1209   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
1210   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
1211
1212   of->write_output_view(offset, oview_size, oview);
1213   of->write_output_view(got_file_offset, got_size, got_view);
1214 }
1215
1216 // Create the PLT section.
1217
1218 void
1219 Target_i386::make_plt_section(Symbol_table* symtab, Layout* layout)
1220 {
1221   if (this->plt_ == NULL)
1222     {
1223       // Create the GOT sections first.
1224       this->got_section(symtab, layout);
1225
1226       this->plt_ = new Output_data_plt_i386(layout, this->got_plt_,
1227                                             this->got_irelative_);
1228       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
1229                                       (elfcpp::SHF_ALLOC
1230                                        | elfcpp::SHF_EXECINSTR),
1231                                       this->plt_, ORDER_PLT, false);
1232
1233       // Make the sh_info field of .rel.plt point to .plt.
1234       Output_section* rel_plt_os = this->plt_->rel_plt()->output_section();
1235       rel_plt_os->set_info_section(this->plt_->output_section());
1236     }
1237 }
1238
1239 // Create a PLT entry for a global symbol.
1240
1241 void
1242 Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym)
1243 {
1244   if (gsym->has_plt_offset())
1245     return;
1246   if (this->plt_ == NULL)
1247     this->make_plt_section(symtab, layout);
1248   this->plt_->add_entry(symtab, layout, gsym);
1249 }
1250
1251 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1252
1253 void
1254 Target_i386::make_local_ifunc_plt_entry(Symbol_table* symtab, Layout* layout,
1255                                         Sized_relobj_file<32, false>* relobj,
1256                                         unsigned int local_sym_index)
1257 {
1258   if (relobj->local_has_plt_offset(local_sym_index))
1259     return;
1260   if (this->plt_ == NULL)
1261     this->make_plt_section(symtab, layout);
1262   unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout,
1263                                                               relobj,
1264                                                               local_sym_index);
1265   relobj->set_local_plt_offset(local_sym_index, plt_offset);
1266 }
1267
1268 // Return the number of entries in the PLT.
1269
1270 unsigned int
1271 Target_i386::plt_entry_count() const
1272 {
1273   if (this->plt_ == NULL)
1274     return 0;
1275   return this->plt_->entry_count();
1276 }
1277
1278 // Return the offset of the first non-reserved PLT entry.
1279
1280 unsigned int
1281 Target_i386::first_plt_entry_offset() const
1282 {
1283   return Output_data_plt_i386::first_plt_entry_offset();
1284 }
1285
1286 // Return the size of each PLT entry.
1287
1288 unsigned int
1289 Target_i386::plt_entry_size() const
1290 {
1291   return Output_data_plt_i386::get_plt_entry_size();
1292 }
1293
1294 // Get the section to use for TLS_DESC relocations.
1295
1296 Target_i386::Reloc_section*
1297 Target_i386::rel_tls_desc_section(Layout* layout) const
1298 {
1299   return this->plt_section()->rel_tls_desc(layout);
1300 }
1301
1302 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1303
1304 void
1305 Target_i386::define_tls_base_symbol(Symbol_table* symtab, Layout* layout)
1306 {
1307   if (this->tls_base_symbol_defined_)
1308     return;
1309
1310   Output_segment* tls_segment = layout->tls_segment();
1311   if (tls_segment != NULL)
1312     {
1313       bool is_exec = parameters->options().output_is_executable();
1314       symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
1315                                        Symbol_table::PREDEFINED,
1316                                        tls_segment, 0, 0,
1317                                        elfcpp::STT_TLS,
1318                                        elfcpp::STB_LOCAL,
1319                                        elfcpp::STV_HIDDEN, 0,
1320                                        (is_exec
1321                                         ? Symbol::SEGMENT_END
1322                                         : Symbol::SEGMENT_START),
1323                                        true);
1324     }
1325   this->tls_base_symbol_defined_ = true;
1326 }
1327
1328 // Create a GOT entry for the TLS module index.
1329
1330 unsigned int
1331 Target_i386::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
1332                                  Sized_relobj_file<32, false>* object)
1333 {
1334   if (this->got_mod_index_offset_ == -1U)
1335     {
1336       gold_assert(symtab != NULL && layout != NULL && object != NULL);
1337       Reloc_section* rel_dyn = this->rel_dyn_section(layout);
1338       Output_data_got<32, false>* got = this->got_section(symtab, layout);
1339       unsigned int got_offset = got->add_constant(0);
1340       rel_dyn->add_local(object, 0, elfcpp::R_386_TLS_DTPMOD32, got,
1341                          got_offset);
1342       got->add_constant(0);
1343       this->got_mod_index_offset_ = got_offset;
1344     }
1345   return this->got_mod_index_offset_;
1346 }
1347
1348 // Optimize the TLS relocation type based on what we know about the
1349 // symbol.  IS_FINAL is true if the final address of this symbol is
1350 // known at link time.
1351
1352 tls::Tls_optimization
1353 Target_i386::optimize_tls_reloc(bool is_final, int r_type)
1354 {
1355   // If we are generating a shared library, then we can't do anything
1356   // in the linker.
1357   if (parameters->options().shared())
1358     return tls::TLSOPT_NONE;
1359
1360   switch (r_type)
1361     {
1362     case elfcpp::R_386_TLS_GD:
1363     case elfcpp::R_386_TLS_GOTDESC:
1364     case elfcpp::R_386_TLS_DESC_CALL:
1365       // These are General-Dynamic which permits fully general TLS
1366       // access.  Since we know that we are generating an executable,
1367       // we can convert this to Initial-Exec.  If we also know that
1368       // this is a local symbol, we can further switch to Local-Exec.
1369       if (is_final)
1370         return tls::TLSOPT_TO_LE;
1371       return tls::TLSOPT_TO_IE;
1372
1373     case elfcpp::R_386_TLS_LDM:
1374       // This is Local-Dynamic, which refers to a local symbol in the
1375       // dynamic TLS block.  Since we know that we generating an
1376       // executable, we can switch to Local-Exec.
1377       return tls::TLSOPT_TO_LE;
1378
1379     case elfcpp::R_386_TLS_LDO_32:
1380       // Another type of Local-Dynamic relocation.
1381       return tls::TLSOPT_TO_LE;
1382
1383     case elfcpp::R_386_TLS_IE:
1384     case elfcpp::R_386_TLS_GOTIE:
1385     case elfcpp::R_386_TLS_IE_32:
1386       // These are Initial-Exec relocs which get the thread offset
1387       // from the GOT.  If we know that we are linking against the
1388       // local symbol, we can switch to Local-Exec, which links the
1389       // thread offset into the instruction.
1390       if (is_final)
1391         return tls::TLSOPT_TO_LE;
1392       return tls::TLSOPT_NONE;
1393
1394     case elfcpp::R_386_TLS_LE:
1395     case elfcpp::R_386_TLS_LE_32:
1396       // When we already have Local-Exec, there is nothing further we
1397       // can do.
1398       return tls::TLSOPT_NONE;
1399
1400     default:
1401       gold_unreachable();
1402     }
1403 }
1404
1405 // Get the Reference_flags for a particular relocation.
1406
1407 int
1408 Target_i386::Scan::get_reference_flags(unsigned int r_type)
1409 {
1410   switch (r_type)
1411     {
1412     case elfcpp::R_386_NONE:
1413     case elfcpp::R_386_GNU_VTINHERIT:
1414     case elfcpp::R_386_GNU_VTENTRY:
1415     case elfcpp::R_386_GOTPC:
1416       // No symbol reference.
1417       return 0;
1418
1419     case elfcpp::R_386_32:
1420     case elfcpp::R_386_16:
1421     case elfcpp::R_386_8:
1422       return Symbol::ABSOLUTE_REF;
1423
1424     case elfcpp::R_386_PC32:
1425     case elfcpp::R_386_PC16:
1426     case elfcpp::R_386_PC8:
1427     case elfcpp::R_386_GOTOFF:
1428       return Symbol::RELATIVE_REF;
1429
1430     case elfcpp::R_386_PLT32:
1431       return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
1432
1433     case elfcpp::R_386_GOT32:
1434       // Absolute in GOT.
1435       return Symbol::ABSOLUTE_REF;
1436
1437     case elfcpp::R_386_TLS_GD:            // Global-dynamic
1438     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
1439     case elfcpp::R_386_TLS_DESC_CALL:
1440     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
1441     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
1442     case elfcpp::R_386_TLS_IE:            // Initial-exec
1443     case elfcpp::R_386_TLS_IE_32:
1444     case elfcpp::R_386_TLS_GOTIE:
1445     case elfcpp::R_386_TLS_LE:            // Local-exec
1446     case elfcpp::R_386_TLS_LE_32:
1447       return Symbol::TLS_REF;
1448
1449     case elfcpp::R_386_COPY:
1450     case elfcpp::R_386_GLOB_DAT:
1451     case elfcpp::R_386_JUMP_SLOT:
1452     case elfcpp::R_386_RELATIVE:
1453     case elfcpp::R_386_IRELATIVE:
1454     case elfcpp::R_386_TLS_TPOFF:
1455     case elfcpp::R_386_TLS_DTPMOD32:
1456     case elfcpp::R_386_TLS_DTPOFF32:
1457     case elfcpp::R_386_TLS_TPOFF32:
1458     case elfcpp::R_386_TLS_DESC:
1459     case elfcpp::R_386_32PLT:
1460     case elfcpp::R_386_TLS_GD_32:
1461     case elfcpp::R_386_TLS_GD_PUSH:
1462     case elfcpp::R_386_TLS_GD_CALL:
1463     case elfcpp::R_386_TLS_GD_POP:
1464     case elfcpp::R_386_TLS_LDM_32:
1465     case elfcpp::R_386_TLS_LDM_PUSH:
1466     case elfcpp::R_386_TLS_LDM_CALL:
1467     case elfcpp::R_386_TLS_LDM_POP:
1468     case elfcpp::R_386_USED_BY_INTEL_200:
1469     default:
1470       // Not expected.  We will give an error later.
1471       return 0;
1472     }
1473 }
1474
1475 // Report an unsupported relocation against a local symbol.
1476
1477 void
1478 Target_i386::Scan::unsupported_reloc_local(Sized_relobj_file<32, false>* object,
1479                                            unsigned int r_type)
1480 {
1481   gold_error(_("%s: unsupported reloc %u against local symbol"),
1482              object->name().c_str(), r_type);
1483 }
1484
1485 // Return whether we need to make a PLT entry for a relocation of a
1486 // given type against a STT_GNU_IFUNC symbol.
1487
1488 bool
1489 Target_i386::Scan::reloc_needs_plt_for_ifunc(
1490     Sized_relobj_file<32, false>* object,
1491     unsigned int r_type)
1492 {
1493   int flags = Scan::get_reference_flags(r_type);
1494   if (flags & Symbol::TLS_REF)
1495     gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
1496                object->name().c_str(), r_type);
1497   return flags != 0;
1498 }
1499
1500 // Scan a relocation for a local symbol.
1501
1502 inline void
1503 Target_i386::Scan::local(Symbol_table* symtab,
1504                          Layout* layout,
1505                          Target_i386* target,
1506                          Sized_relobj_file<32, false>* object,
1507                          unsigned int data_shndx,
1508                          Output_section* output_section,
1509                          const elfcpp::Rel<32, false>& reloc,
1510                          unsigned int r_type,
1511                          const elfcpp::Sym<32, false>& lsym)
1512 {
1513   // A local STT_GNU_IFUNC symbol may require a PLT entry.
1514   if (lsym.get_st_type() == elfcpp::STT_GNU_IFUNC
1515       && this->reloc_needs_plt_for_ifunc(object, r_type))
1516     {
1517       unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1518       target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
1519     }
1520
1521   switch (r_type)
1522     {
1523     case elfcpp::R_386_NONE:
1524     case elfcpp::R_386_GNU_VTINHERIT:
1525     case elfcpp::R_386_GNU_VTENTRY:
1526       break;
1527
1528     case elfcpp::R_386_32:
1529       // If building a shared library (or a position-independent
1530       // executable), we need to create a dynamic relocation for
1531       // this location. The relocation applied at link time will
1532       // apply the link-time value, so we flag the location with
1533       // an R_386_RELATIVE relocation so the dynamic loader can
1534       // relocate it easily.
1535       if (parameters->options().output_is_position_independent())
1536         {
1537           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1538           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1539           rel_dyn->add_local_relative(object, r_sym, elfcpp::R_386_RELATIVE,
1540                                       output_section, data_shndx,
1541                                       reloc.get_r_offset());
1542         }
1543       break;
1544
1545     case elfcpp::R_386_16:
1546     case elfcpp::R_386_8:
1547       // If building a shared library (or a position-independent
1548       // executable), we need to create a dynamic relocation for
1549       // this location. Because the addend needs to remain in the
1550       // data section, we need to be careful not to apply this
1551       // relocation statically.
1552       if (parameters->options().output_is_position_independent())
1553         {
1554           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1555           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1556           if (lsym.get_st_type() != elfcpp::STT_SECTION)
1557             rel_dyn->add_local(object, r_sym, r_type, output_section,
1558                                data_shndx, reloc.get_r_offset());
1559           else
1560             {
1561               gold_assert(lsym.get_st_value() == 0);
1562               unsigned int shndx = lsym.get_st_shndx();
1563               bool is_ordinary;
1564               shndx = object->adjust_sym_shndx(r_sym, shndx,
1565                                                &is_ordinary);
1566               if (!is_ordinary)
1567                 object->error(_("section symbol %u has bad shndx %u"),
1568                               r_sym, shndx);
1569               else
1570                 rel_dyn->add_local_section(object, shndx,
1571                                            r_type, output_section,
1572                                            data_shndx, reloc.get_r_offset());
1573             }
1574         }
1575       break;
1576
1577     case elfcpp::R_386_PC32:
1578     case elfcpp::R_386_PC16:
1579     case elfcpp::R_386_PC8:
1580       break;
1581
1582     case elfcpp::R_386_PLT32:
1583       // Since we know this is a local symbol, we can handle this as a
1584       // PC32 reloc.
1585       break;
1586
1587     case elfcpp::R_386_GOTOFF:
1588     case elfcpp::R_386_GOTPC:
1589       // We need a GOT section.
1590       target->got_section(symtab, layout);
1591       break;
1592
1593     case elfcpp::R_386_GOT32:
1594       {
1595         // The symbol requires a GOT entry.
1596         Output_data_got<32, false>* got = target->got_section(symtab, layout);
1597         unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1598
1599         // For a STT_GNU_IFUNC symbol we want the PLT offset.  That
1600         // lets function pointers compare correctly with shared
1601         // libraries.  Otherwise we would need an IRELATIVE reloc.
1602         bool is_new;
1603         if (lsym.get_st_type() == elfcpp::STT_GNU_IFUNC)
1604           is_new = got->add_local_plt(object, r_sym, GOT_TYPE_STANDARD);
1605         else
1606           is_new = got->add_local(object, r_sym, GOT_TYPE_STANDARD);
1607         if (is_new)
1608           {
1609             // If we are generating a shared object, we need to add a
1610             // dynamic RELATIVE relocation for this symbol's GOT entry.
1611             if (parameters->options().output_is_position_independent())
1612               {
1613                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1614                 unsigned int got_offset =
1615                   object->local_got_offset(r_sym, GOT_TYPE_STANDARD);
1616                 rel_dyn->add_local_relative(object, r_sym,
1617                                             elfcpp::R_386_RELATIVE,
1618                                             got, got_offset);
1619               }
1620           }
1621       }
1622       break;
1623
1624       // These are relocations which should only be seen by the
1625       // dynamic linker, and should never be seen here.
1626     case elfcpp::R_386_COPY:
1627     case elfcpp::R_386_GLOB_DAT:
1628     case elfcpp::R_386_JUMP_SLOT:
1629     case elfcpp::R_386_RELATIVE:
1630     case elfcpp::R_386_IRELATIVE:
1631     case elfcpp::R_386_TLS_TPOFF:
1632     case elfcpp::R_386_TLS_DTPMOD32:
1633     case elfcpp::R_386_TLS_DTPOFF32:
1634     case elfcpp::R_386_TLS_TPOFF32:
1635     case elfcpp::R_386_TLS_DESC:
1636       gold_error(_("%s: unexpected reloc %u in object file"),
1637                  object->name().c_str(), r_type);
1638       break;
1639
1640       // These are initial TLS relocs, which are expected when
1641       // linking.
1642     case elfcpp::R_386_TLS_GD:            // Global-dynamic
1643     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
1644     case elfcpp::R_386_TLS_DESC_CALL:
1645     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
1646     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
1647     case elfcpp::R_386_TLS_IE:            // Initial-exec
1648     case elfcpp::R_386_TLS_IE_32:
1649     case elfcpp::R_386_TLS_GOTIE:
1650     case elfcpp::R_386_TLS_LE:            // Local-exec
1651     case elfcpp::R_386_TLS_LE_32:
1652       {
1653         bool output_is_shared = parameters->options().shared();
1654         const tls::Tls_optimization optimized_type
1655             = Target_i386::optimize_tls_reloc(!output_is_shared, r_type);
1656         switch (r_type)
1657           {
1658           case elfcpp::R_386_TLS_GD:          // Global-dynamic
1659             if (optimized_type == tls::TLSOPT_NONE)
1660               {
1661                 // Create a pair of GOT entries for the module index and
1662                 // dtv-relative offset.
1663                 Output_data_got<32, false>* got
1664                     = target->got_section(symtab, layout);
1665                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1666                 unsigned int shndx = lsym.get_st_shndx();
1667                 bool is_ordinary;
1668                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1669                 if (!is_ordinary)
1670                   object->error(_("local symbol %u has bad shndx %u"),
1671                               r_sym, shndx);
1672                 else
1673                   got->add_local_pair_with_rel(object, r_sym, shndx,
1674                                                GOT_TYPE_TLS_PAIR,
1675                                                target->rel_dyn_section(layout),
1676                                                elfcpp::R_386_TLS_DTPMOD32, 0);
1677               }
1678             else if (optimized_type != tls::TLSOPT_TO_LE)
1679               unsupported_reloc_local(object, r_type);
1680             break;
1681
1682           case elfcpp::R_386_TLS_GOTDESC:     // Global-dynamic (from ~oliva)
1683             target->define_tls_base_symbol(symtab, layout);
1684             if (optimized_type == tls::TLSOPT_NONE)
1685               {
1686                 // Create a double GOT entry with an R_386_TLS_DESC
1687                 // reloc.  The R_386_TLS_DESC reloc is resolved
1688                 // lazily, so the GOT entry needs to be in an area in
1689                 // .got.plt, not .got.  Call got_section to make sure
1690                 // the section has been created.
1691                 target->got_section(symtab, layout);
1692                 Output_data_got<32, false>* got = target->got_tlsdesc_section();
1693                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1694                 if (!object->local_has_got_offset(r_sym, GOT_TYPE_TLS_DESC))
1695                   {
1696                     unsigned int got_offset = got->add_constant(0);
1697                     // The local symbol value is stored in the second
1698                     // GOT entry.
1699                     got->add_local(object, r_sym, GOT_TYPE_TLS_DESC);
1700                     // That set the GOT offset of the local symbol to
1701                     // point to the second entry, but we want it to
1702                     // point to the first.
1703                     object->set_local_got_offset(r_sym, GOT_TYPE_TLS_DESC,
1704                                                  got_offset);
1705                     Reloc_section* rt = target->rel_tls_desc_section(layout);
1706                     rt->add_absolute(elfcpp::R_386_TLS_DESC, got, got_offset);
1707                   }
1708               }
1709             else if (optimized_type != tls::TLSOPT_TO_LE)
1710               unsupported_reloc_local(object, r_type);
1711             break;
1712
1713           case elfcpp::R_386_TLS_DESC_CALL:
1714             break;
1715
1716           case elfcpp::R_386_TLS_LDM:         // Local-dynamic
1717             if (optimized_type == tls::TLSOPT_NONE)
1718               {
1719                 // Create a GOT entry for the module index.
1720                 target->got_mod_index_entry(symtab, layout, object);
1721               }
1722             else if (optimized_type != tls::TLSOPT_TO_LE)
1723               unsupported_reloc_local(object, r_type);
1724             break;
1725
1726           case elfcpp::R_386_TLS_LDO_32:      // Alternate local-dynamic
1727             break;
1728
1729           case elfcpp::R_386_TLS_IE:          // Initial-exec
1730           case elfcpp::R_386_TLS_IE_32:
1731           case elfcpp::R_386_TLS_GOTIE:
1732             layout->set_has_static_tls();
1733             if (optimized_type == tls::TLSOPT_NONE)
1734               {
1735                 // For the R_386_TLS_IE relocation, we need to create a
1736                 // dynamic relocation when building a shared library.
1737                 if (r_type == elfcpp::R_386_TLS_IE
1738                     && parameters->options().shared())
1739                   {
1740                     Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1741                     unsigned int r_sym
1742                         = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1743                     rel_dyn->add_local_relative(object, r_sym,
1744                                                 elfcpp::R_386_RELATIVE,
1745                                                 output_section, data_shndx,
1746                                                 reloc.get_r_offset());
1747                   }
1748                 // Create a GOT entry for the tp-relative offset.
1749                 Output_data_got<32, false>* got
1750                     = target->got_section(symtab, layout);
1751                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1752                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
1753                                            ? elfcpp::R_386_TLS_TPOFF32
1754                                            : elfcpp::R_386_TLS_TPOFF);
1755                 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
1756                                          ? GOT_TYPE_TLS_OFFSET
1757                                          : GOT_TYPE_TLS_NOFFSET);
1758                 got->add_local_with_rel(object, r_sym, got_type,
1759                                         target->rel_dyn_section(layout),
1760                                         dyn_r_type);
1761               }
1762             else if (optimized_type != tls::TLSOPT_TO_LE)
1763               unsupported_reloc_local(object, r_type);
1764             break;
1765
1766           case elfcpp::R_386_TLS_LE:          // Local-exec
1767           case elfcpp::R_386_TLS_LE_32:
1768             layout->set_has_static_tls();
1769             if (output_is_shared)
1770               {
1771                 // We need to create a dynamic relocation.
1772                 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
1773                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1774                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
1775                                            ? elfcpp::R_386_TLS_TPOFF32
1776                                            : elfcpp::R_386_TLS_TPOFF);
1777                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1778                 rel_dyn->add_local(object, r_sym, dyn_r_type, output_section,
1779                                    data_shndx, reloc.get_r_offset());
1780               }
1781             break;
1782
1783           default:
1784             gold_unreachable();
1785           }
1786       }
1787       break;
1788
1789     case elfcpp::R_386_32PLT:
1790     case elfcpp::R_386_TLS_GD_32:
1791     case elfcpp::R_386_TLS_GD_PUSH:
1792     case elfcpp::R_386_TLS_GD_CALL:
1793     case elfcpp::R_386_TLS_GD_POP:
1794     case elfcpp::R_386_TLS_LDM_32:
1795     case elfcpp::R_386_TLS_LDM_PUSH:
1796     case elfcpp::R_386_TLS_LDM_CALL:
1797     case elfcpp::R_386_TLS_LDM_POP:
1798     case elfcpp::R_386_USED_BY_INTEL_200:
1799     default:
1800       unsupported_reloc_local(object, r_type);
1801       break;
1802     }
1803 }
1804
1805 // Report an unsupported relocation against a global symbol.
1806
1807 void
1808 Target_i386::Scan::unsupported_reloc_global(
1809     Sized_relobj_file<32, false>* object,
1810     unsigned int r_type,
1811     Symbol* gsym)
1812 {
1813   gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1814              object->name().c_str(), r_type, gsym->demangled_name().c_str());
1815 }
1816
1817 inline bool
1818 Target_i386::Scan::possible_function_pointer_reloc(unsigned int r_type)
1819 {
1820   switch (r_type)
1821     {
1822     case elfcpp::R_386_32:
1823     case elfcpp::R_386_16:
1824     case elfcpp::R_386_8:
1825     case elfcpp::R_386_GOTOFF:
1826     case elfcpp::R_386_GOT32:
1827       {
1828         return true;
1829       }
1830     default:
1831       return false;
1832     }
1833   return false;
1834 }
1835
1836 inline bool
1837 Target_i386::Scan::local_reloc_may_be_function_pointer(
1838   Symbol_table* ,
1839   Layout* ,
1840   Target_i386* ,
1841   Sized_relobj_file<32, false>* ,
1842   unsigned int ,
1843   Output_section* ,
1844   const elfcpp::Rel<32, false>& ,
1845   unsigned int r_type,
1846   const elfcpp::Sym<32, false>&)
1847 {
1848   return possible_function_pointer_reloc(r_type);
1849 }
1850
1851 inline bool
1852 Target_i386::Scan::global_reloc_may_be_function_pointer(
1853   Symbol_table* ,
1854   Layout* ,
1855   Target_i386* ,
1856   Sized_relobj_file<32, false>* ,
1857   unsigned int ,
1858   Output_section* ,
1859   const elfcpp::Rel<32, false>& ,
1860   unsigned int r_type,
1861   Symbol*)
1862 {
1863   return possible_function_pointer_reloc(r_type);
1864 }
1865
1866 // Scan a relocation for a global symbol.
1867
1868 inline void
1869 Target_i386::Scan::global(Symbol_table* symtab,
1870                           Layout* layout,
1871                           Target_i386* target,
1872                           Sized_relobj_file<32, false>* object,
1873                           unsigned int data_shndx,
1874                           Output_section* output_section,
1875                           const elfcpp::Rel<32, false>& reloc,
1876                           unsigned int r_type,
1877                           Symbol* gsym)
1878 {
1879   // A STT_GNU_IFUNC symbol may require a PLT entry.
1880   if (gsym->type() == elfcpp::STT_GNU_IFUNC
1881       && this->reloc_needs_plt_for_ifunc(object, r_type))
1882     target->make_plt_entry(symtab, layout, gsym);
1883
1884   switch (r_type)
1885     {
1886     case elfcpp::R_386_NONE:
1887     case elfcpp::R_386_GNU_VTINHERIT:
1888     case elfcpp::R_386_GNU_VTENTRY:
1889       break;
1890
1891     case elfcpp::R_386_32:
1892     case elfcpp::R_386_16:
1893     case elfcpp::R_386_8:
1894       {
1895         // Make a PLT entry if necessary.
1896         if (gsym->needs_plt_entry())
1897           {
1898             target->make_plt_entry(symtab, layout, gsym);
1899             // Since this is not a PC-relative relocation, we may be
1900             // taking the address of a function. In that case we need to
1901             // set the entry in the dynamic symbol table to the address of
1902             // the PLT entry.
1903             if (gsym->is_from_dynobj() && !parameters->options().shared())
1904               gsym->set_needs_dynsym_value();
1905           }
1906         // Make a dynamic relocation if necessary.
1907         if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
1908           {
1909             if (gsym->may_need_copy_reloc())
1910               {
1911                 target->copy_reloc(symtab, layout, object,
1912                                    data_shndx, output_section, gsym, reloc);
1913               }
1914             else if (r_type == elfcpp::R_386_32
1915                      && gsym->type() == elfcpp::STT_GNU_IFUNC
1916                      && gsym->can_use_relative_reloc(false)
1917                      && !gsym->is_from_dynobj()
1918                      && !gsym->is_undefined()
1919                      && !gsym->is_preemptible())
1920               {
1921                 // Use an IRELATIVE reloc for a locally defined
1922                 // STT_GNU_IFUNC symbol.  This makes a function
1923                 // address in a PIE executable match the address in a
1924                 // shared library that it links against.
1925                 Reloc_section* rel_dyn = target->rel_irelative_section(layout);
1926                 rel_dyn->add_symbolless_global_addend(gsym,
1927                                                       elfcpp::R_386_IRELATIVE,
1928                                                       output_section,
1929                                                       object, data_shndx,
1930                                                       reloc.get_r_offset());
1931               }
1932             else if (r_type == elfcpp::R_386_32
1933                      && gsym->can_use_relative_reloc(false))
1934               {
1935                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1936                 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1937                                              output_section, object,
1938                                              data_shndx, reloc.get_r_offset());
1939               }
1940             else
1941               {
1942                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1943                 rel_dyn->add_global(gsym, r_type, output_section, object,
1944                                     data_shndx, reloc.get_r_offset());
1945               }
1946           }
1947       }
1948       break;
1949
1950     case elfcpp::R_386_PC32:
1951     case elfcpp::R_386_PC16:
1952     case elfcpp::R_386_PC8:
1953       {
1954         // Make a PLT entry if necessary.
1955         if (gsym->needs_plt_entry())
1956           {
1957             // These relocations are used for function calls only in
1958             // non-PIC code.  For a 32-bit relocation in a shared library,
1959             // we'll need a text relocation anyway, so we can skip the
1960             // PLT entry and let the dynamic linker bind the call directly
1961             // to the target.  For smaller relocations, we should use a
1962             // PLT entry to ensure that the call can reach.
1963             if (!parameters->options().shared()
1964                 || r_type != elfcpp::R_386_PC32)
1965               target->make_plt_entry(symtab, layout, gsym);
1966           }
1967         // Make a dynamic relocation if necessary.
1968         if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
1969           {
1970             if (gsym->may_need_copy_reloc())
1971               {
1972                 target->copy_reloc(symtab, layout, object,
1973                                    data_shndx, output_section, gsym, reloc);
1974               }
1975             else
1976               {
1977                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1978                 rel_dyn->add_global(gsym, r_type, output_section, object,
1979                                     data_shndx, reloc.get_r_offset());
1980               }
1981           }
1982       }
1983       break;
1984
1985     case elfcpp::R_386_GOT32:
1986       {
1987         // The symbol requires a GOT entry.
1988         Output_data_got<32, false>* got = target->got_section(symtab, layout);
1989         if (gsym->final_value_is_known())
1990           {
1991             // For a STT_GNU_IFUNC symbol we want the PLT address.
1992             if (gsym->type() == elfcpp::STT_GNU_IFUNC)
1993               got->add_global_plt(gsym, GOT_TYPE_STANDARD);
1994             else
1995               got->add_global(gsym, GOT_TYPE_STANDARD);
1996           }
1997         else
1998           {
1999             // If this symbol is not fully resolved, we need to add a
2000             // GOT entry with a dynamic relocation.
2001             Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2002
2003             // Use a GLOB_DAT rather than a RELATIVE reloc if:
2004             //
2005             // 1) The symbol may be defined in some other module.
2006             //
2007             // 2) We are building a shared library and this is a
2008             // protected symbol; using GLOB_DAT means that the dynamic
2009             // linker can use the address of the PLT in the main
2010             // executable when appropriate so that function address
2011             // comparisons work.
2012             //
2013             // 3) This is a STT_GNU_IFUNC symbol in position dependent
2014             // code, again so that function address comparisons work.
2015             if (gsym->is_from_dynobj()
2016                 || gsym->is_undefined()
2017                 || gsym->is_preemptible()
2018                 || (gsym->visibility() == elfcpp::STV_PROTECTED
2019                     && parameters->options().shared())
2020                 || (gsym->type() == elfcpp::STT_GNU_IFUNC
2021                     && parameters->options().output_is_position_independent()))
2022               got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
2023                                        rel_dyn, elfcpp::R_386_GLOB_DAT);
2024             else
2025               {
2026                 // For a STT_GNU_IFUNC symbol we want to write the PLT
2027                 // offset into the GOT, so that function pointer
2028                 // comparisons work correctly.
2029                 bool is_new;
2030                 if (gsym->type() != elfcpp::STT_GNU_IFUNC)
2031                   is_new = got->add_global(gsym, GOT_TYPE_STANDARD);
2032                 else
2033                   {
2034                     is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD);
2035                     // Tell the dynamic linker to use the PLT address
2036                     // when resolving relocations.
2037                     if (gsym->is_from_dynobj()
2038                         && !parameters->options().shared())
2039                       gsym->set_needs_dynsym_value();
2040                   }
2041                 if (is_new)
2042                   {
2043                     unsigned int got_off = gsym->got_offset(GOT_TYPE_STANDARD);
2044                     rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
2045                                                  got, got_off);
2046                   }
2047               }
2048           }
2049       }
2050       break;
2051
2052     case elfcpp::R_386_PLT32:
2053       // If the symbol is fully resolved, this is just a PC32 reloc.
2054       // Otherwise we need a PLT entry.
2055       if (gsym->final_value_is_known())
2056         break;
2057       // If building a shared library, we can also skip the PLT entry
2058       // if the symbol is defined in the output file and is protected
2059       // or hidden.
2060       if (gsym->is_defined()
2061           && !gsym->is_from_dynobj()
2062           && !gsym->is_preemptible())
2063         break;
2064       target->make_plt_entry(symtab, layout, gsym);
2065       break;
2066
2067     case elfcpp::R_386_GOTOFF:
2068     case elfcpp::R_386_GOTPC:
2069       // We need a GOT section.
2070       target->got_section(symtab, layout);
2071       break;
2072
2073       // These are relocations which should only be seen by the
2074       // dynamic linker, and should never be seen here.
2075     case elfcpp::R_386_COPY:
2076     case elfcpp::R_386_GLOB_DAT:
2077     case elfcpp::R_386_JUMP_SLOT:
2078     case elfcpp::R_386_RELATIVE:
2079     case elfcpp::R_386_IRELATIVE:
2080     case elfcpp::R_386_TLS_TPOFF:
2081     case elfcpp::R_386_TLS_DTPMOD32:
2082     case elfcpp::R_386_TLS_DTPOFF32:
2083     case elfcpp::R_386_TLS_TPOFF32:
2084     case elfcpp::R_386_TLS_DESC:
2085       gold_error(_("%s: unexpected reloc %u in object file"),
2086                  object->name().c_str(), r_type);
2087       break;
2088
2089       // These are initial tls relocs, which are expected when
2090       // linking.
2091     case elfcpp::R_386_TLS_GD:            // Global-dynamic
2092     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
2093     case elfcpp::R_386_TLS_DESC_CALL:
2094     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
2095     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
2096     case elfcpp::R_386_TLS_IE:            // Initial-exec
2097     case elfcpp::R_386_TLS_IE_32:
2098     case elfcpp::R_386_TLS_GOTIE:
2099     case elfcpp::R_386_TLS_LE:            // Local-exec
2100     case elfcpp::R_386_TLS_LE_32:
2101       {
2102         const bool is_final = gsym->final_value_is_known();
2103         const tls::Tls_optimization optimized_type
2104             = Target_i386::optimize_tls_reloc(is_final, r_type);
2105         switch (r_type)
2106           {
2107           case elfcpp::R_386_TLS_GD:          // Global-dynamic
2108             if (optimized_type == tls::TLSOPT_NONE)
2109               {
2110                 // Create a pair of GOT entries for the module index and
2111                 // dtv-relative offset.
2112                 Output_data_got<32, false>* got
2113                     = target->got_section(symtab, layout);
2114                 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
2115                                              target->rel_dyn_section(layout),
2116                                              elfcpp::R_386_TLS_DTPMOD32,
2117                                              elfcpp::R_386_TLS_DTPOFF32);
2118               }
2119             else if (optimized_type == tls::TLSOPT_TO_IE)
2120               {
2121                 // Create a GOT entry for the tp-relative offset.
2122                 Output_data_got<32, false>* got
2123                     = target->got_section(symtab, layout);
2124                 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
2125                                          target->rel_dyn_section(layout),
2126                                          elfcpp::R_386_TLS_TPOFF);
2127               }
2128             else if (optimized_type != tls::TLSOPT_TO_LE)
2129               unsupported_reloc_global(object, r_type, gsym);
2130             break;
2131
2132           case elfcpp::R_386_TLS_GOTDESC:     // Global-dynamic (~oliva url)
2133             target->define_tls_base_symbol(symtab, layout);
2134             if (optimized_type == tls::TLSOPT_NONE)
2135               {
2136                 // Create a double GOT entry with an R_386_TLS_DESC
2137                 // reloc.  The R_386_TLS_DESC reloc is resolved
2138                 // lazily, so the GOT entry needs to be in an area in
2139                 // .got.plt, not .got.  Call got_section to make sure
2140                 // the section has been created.
2141                 target->got_section(symtab, layout);
2142                 Output_data_got<32, false>* got = target->got_tlsdesc_section();
2143                 Reloc_section* rt = target->rel_tls_desc_section(layout);
2144                 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC, rt,
2145                                              elfcpp::R_386_TLS_DESC, 0);
2146               }
2147             else if (optimized_type == tls::TLSOPT_TO_IE)
2148               {
2149                 // Create a GOT entry for the tp-relative offset.
2150                 Output_data_got<32, false>* got
2151                     = target->got_section(symtab, layout);
2152                 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
2153                                          target->rel_dyn_section(layout),
2154                                          elfcpp::R_386_TLS_TPOFF);
2155               }
2156             else if (optimized_type != tls::TLSOPT_TO_LE)
2157               unsupported_reloc_global(object, r_type, gsym);
2158             break;
2159
2160           case elfcpp::R_386_TLS_DESC_CALL:
2161             break;
2162
2163           case elfcpp::R_386_TLS_LDM:         // Local-dynamic
2164             if (optimized_type == tls::TLSOPT_NONE)
2165               {
2166                 // Create a GOT entry for the module index.
2167                 target->got_mod_index_entry(symtab, layout, object);
2168               }
2169             else if (optimized_type != tls::TLSOPT_TO_LE)
2170               unsupported_reloc_global(object, r_type, gsym);
2171             break;
2172
2173           case elfcpp::R_386_TLS_LDO_32:      // Alternate local-dynamic
2174             break;
2175
2176           case elfcpp::R_386_TLS_IE:          // Initial-exec
2177           case elfcpp::R_386_TLS_IE_32:
2178           case elfcpp::R_386_TLS_GOTIE:
2179             layout->set_has_static_tls();
2180             if (optimized_type == tls::TLSOPT_NONE)
2181               {
2182                 // For the R_386_TLS_IE relocation, we need to create a
2183                 // dynamic relocation when building a shared library.
2184                 if (r_type == elfcpp::R_386_TLS_IE
2185                     && parameters->options().shared())
2186                   {
2187                     Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2188                     rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
2189                                                  output_section, object,
2190                                                  data_shndx,
2191                                                  reloc.get_r_offset());
2192                   }
2193                 // Create a GOT entry for the tp-relative offset.
2194                 Output_data_got<32, false>* got
2195                     = target->got_section(symtab, layout);
2196                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
2197                                            ? elfcpp::R_386_TLS_TPOFF32
2198                                            : elfcpp::R_386_TLS_TPOFF);
2199                 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
2200                                          ? GOT_TYPE_TLS_OFFSET
2201                                          : GOT_TYPE_TLS_NOFFSET);
2202                 got->add_global_with_rel(gsym, got_type,
2203                                          target->rel_dyn_section(layout),
2204                                          dyn_r_type);
2205               }
2206             else if (optimized_type != tls::TLSOPT_TO_LE)
2207               unsupported_reloc_global(object, r_type, gsym);
2208             break;
2209
2210           case elfcpp::R_386_TLS_LE:          // Local-exec
2211           case elfcpp::R_386_TLS_LE_32:
2212             layout->set_has_static_tls();
2213             if (parameters->options().shared())
2214               {
2215                 // We need to create a dynamic relocation.
2216                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
2217                                            ? elfcpp::R_386_TLS_TPOFF32
2218                                            : elfcpp::R_386_TLS_TPOFF);
2219                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2220                 rel_dyn->add_global(gsym, dyn_r_type, output_section, object,
2221                                     data_shndx, reloc.get_r_offset());
2222               }
2223             break;
2224
2225           default:
2226             gold_unreachable();
2227           }
2228       }
2229       break;
2230
2231     case elfcpp::R_386_32PLT:
2232     case elfcpp::R_386_TLS_GD_32:
2233     case elfcpp::R_386_TLS_GD_PUSH:
2234     case elfcpp::R_386_TLS_GD_CALL:
2235     case elfcpp::R_386_TLS_GD_POP:
2236     case elfcpp::R_386_TLS_LDM_32:
2237     case elfcpp::R_386_TLS_LDM_PUSH:
2238     case elfcpp::R_386_TLS_LDM_CALL:
2239     case elfcpp::R_386_TLS_LDM_POP:
2240     case elfcpp::R_386_USED_BY_INTEL_200:
2241     default:
2242       unsupported_reloc_global(object, r_type, gsym);
2243       break;
2244     }
2245 }
2246
2247 // Process relocations for gc.
2248
2249 void
2250 Target_i386::gc_process_relocs(Symbol_table* symtab,
2251                                Layout* layout,
2252                                Sized_relobj_file<32, false>* object,
2253                                unsigned int data_shndx,
2254                                unsigned int,
2255                                const unsigned char* prelocs,
2256                                size_t reloc_count,
2257                                Output_section* output_section,
2258                                bool needs_special_offset_handling,
2259                                size_t local_symbol_count,
2260                                const unsigned char* plocal_symbols)
2261 {
2262   gold::gc_process_relocs<32, false, Target_i386, elfcpp::SHT_REL,
2263                           Target_i386::Scan,
2264                           Target_i386::Relocatable_size_for_reloc>(
2265     symtab,
2266     layout,
2267     this,
2268     object,
2269     data_shndx,
2270     prelocs,
2271     reloc_count,
2272     output_section,
2273     needs_special_offset_handling,
2274     local_symbol_count,
2275     plocal_symbols);
2276 }
2277
2278 // Scan relocations for a section.
2279
2280 void
2281 Target_i386::scan_relocs(Symbol_table* symtab,
2282                          Layout* layout,
2283                          Sized_relobj_file<32, false>* object,
2284                          unsigned int data_shndx,
2285                          unsigned int sh_type,
2286                          const unsigned char* prelocs,
2287                          size_t reloc_count,
2288                          Output_section* output_section,
2289                          bool needs_special_offset_handling,
2290                          size_t local_symbol_count,
2291                          const unsigned char* plocal_symbols)
2292 {
2293   if (sh_type == elfcpp::SHT_RELA)
2294     {
2295       gold_error(_("%s: unsupported RELA reloc section"),
2296                  object->name().c_str());
2297       return;
2298     }
2299
2300   gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL,
2301                     Target_i386::Scan>(
2302     symtab,
2303     layout,
2304     this,
2305     object,
2306     data_shndx,
2307     prelocs,
2308     reloc_count,
2309     output_section,
2310     needs_special_offset_handling,
2311     local_symbol_count,
2312     plocal_symbols);
2313 }
2314
2315 // Finalize the sections.
2316
2317 void
2318 Target_i386::do_finalize_sections(
2319     Layout* layout,
2320     const Input_objects*,
2321     Symbol_table* symtab)
2322 {
2323   const Reloc_section* rel_plt = (this->plt_ == NULL
2324                                   ? NULL
2325                                   : this->plt_->rel_plt());
2326   layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
2327                                   this->rel_dyn_, true, false);
2328
2329   // Emit any relocs we saved in an attempt to avoid generating COPY
2330   // relocs.
2331   if (this->copy_relocs_.any_saved_relocs())
2332     this->copy_relocs_.emit(this->rel_dyn_section(layout));
2333
2334   // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
2335   // the .got.plt section.
2336   Symbol* sym = this->global_offset_table_;
2337   if (sym != NULL)
2338     {
2339       uint32_t data_size = this->got_plt_->current_data_size();
2340       symtab->get_sized_symbol<32>(sym)->set_symsize(data_size);
2341     }
2342
2343   if (parameters->doing_static_link()
2344       && (this->plt_ == NULL || !this->plt_->has_irelative_section()))
2345     {
2346       // If linking statically, make sure that the __rel_iplt symbols
2347       // were defined if necessary, even if we didn't create a PLT.
2348       static const Define_symbol_in_segment syms[] =
2349         {
2350           {
2351             "__rel_iplt_start",         // name
2352             elfcpp::PT_LOAD,            // segment_type
2353             elfcpp::PF_W,               // segment_flags_set
2354             elfcpp::PF(0),              // segment_flags_clear
2355             0,                          // value
2356             0,                          // size
2357             elfcpp::STT_NOTYPE,         // type
2358             elfcpp::STB_GLOBAL,         // binding
2359             elfcpp::STV_HIDDEN,         // visibility
2360             0,                          // nonvis
2361             Symbol::SEGMENT_START,      // offset_from_base
2362             true                        // only_if_ref
2363           },
2364           {
2365             "__rel_iplt_end",           // name
2366             elfcpp::PT_LOAD,            // segment_type
2367             elfcpp::PF_W,               // segment_flags_set
2368             elfcpp::PF(0),              // segment_flags_clear
2369             0,                          // value
2370             0,                          // size
2371             elfcpp::STT_NOTYPE,         // type
2372             elfcpp::STB_GLOBAL,         // binding
2373             elfcpp::STV_HIDDEN,         // visibility
2374             0,                          // nonvis
2375             Symbol::SEGMENT_START,      // offset_from_base
2376             true                        // only_if_ref
2377           }
2378         };
2379
2380       symtab->define_symbols(layout, 2, syms,
2381                              layout->script_options()->saw_sections_clause());
2382     }
2383 }
2384
2385 // Return whether a direct absolute static relocation needs to be applied.
2386 // In cases where Scan::local() or Scan::global() has created
2387 // a dynamic relocation other than R_386_RELATIVE, the addend
2388 // of the relocation is carried in the data, and we must not
2389 // apply the static relocation.
2390
2391 inline bool
2392 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol<32>* gsym,
2393                                                  unsigned int r_type,
2394                                                  bool is_32bit,
2395                                                  Output_section* output_section)
2396 {
2397   // If the output section is not allocated, then we didn't call
2398   // scan_relocs, we didn't create a dynamic reloc, and we must apply
2399   // the reloc here.
2400   if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
2401     return true;
2402
2403   int ref_flags = Scan::get_reference_flags(r_type);
2404
2405   // For local symbols, we will have created a non-RELATIVE dynamic
2406   // relocation only if (a) the output is position independent,
2407   // (b) the relocation is absolute (not pc- or segment-relative), and
2408   // (c) the relocation is not 32 bits wide.
2409   if (gsym == NULL)
2410     return !(parameters->options().output_is_position_independent()
2411              && (ref_flags & Symbol::ABSOLUTE_REF)
2412              && !is_32bit);
2413
2414   // For global symbols, we use the same helper routines used in the
2415   // scan pass.  If we did not create a dynamic relocation, or if we
2416   // created a RELATIVE dynamic relocation, we should apply the static
2417   // relocation.
2418   bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
2419   bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
2420                 && gsym->can_use_relative_reloc(ref_flags
2421                                                 & Symbol::FUNCTION_CALL);
2422   return !has_dyn || is_rel;
2423 }
2424
2425 // Perform a relocation.
2426
2427 inline bool
2428 Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
2429                                 Target_i386* target,
2430                                 Output_section* output_section,
2431                                 size_t relnum,
2432                                 const elfcpp::Rel<32, false>& rel,
2433                                 unsigned int r_type,
2434                                 const Sized_symbol<32>* gsym,
2435                                 const Symbol_value<32>* psymval,
2436                                 unsigned char* view,
2437                                 elfcpp::Elf_types<32>::Elf_Addr address,
2438                                 section_size_type view_size)
2439 {
2440   if (this->skip_call_tls_get_addr_)
2441     {
2442       if ((r_type != elfcpp::R_386_PLT32
2443            && r_type != elfcpp::R_386_PC32)
2444           || gsym == NULL
2445           || strcmp(gsym->name(), "___tls_get_addr") != 0)
2446         gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2447                                _("missing expected TLS relocation"));
2448       else
2449         {
2450           this->skip_call_tls_get_addr_ = false;
2451           return false;
2452         }
2453     }
2454
2455   const Sized_relobj_file<32, false>* object = relinfo->object;
2456
2457   // Pick the value to use for symbols defined in shared objects.
2458   Symbol_value<32> symval;
2459   if (gsym != NULL
2460       && gsym->type() == elfcpp::STT_GNU_IFUNC
2461       && r_type == elfcpp::R_386_32
2462       && gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type))
2463       && gsym->can_use_relative_reloc(false)
2464       && !gsym->is_from_dynobj()
2465       && !gsym->is_undefined()
2466       && !gsym->is_preemptible())
2467     {
2468       // In this case we are generating a R_386_IRELATIVE reloc.  We
2469       // want to use the real value of the symbol, not the PLT offset.
2470     }
2471   else if (gsym != NULL
2472            && gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
2473     {
2474       symval.set_output_value(target->plt_address_for_global(gsym)
2475                               + gsym->plt_offset());
2476       psymval = &symval;
2477     }
2478   else if (gsym == NULL && psymval->is_ifunc_symbol())
2479     {
2480       unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2481       if (object->local_has_plt_offset(r_sym))
2482         {
2483           symval.set_output_value(target->plt_address_for_local(object, r_sym)
2484                                   + object->local_plt_offset(r_sym));
2485           psymval = &symval;
2486         }
2487     }
2488
2489   // Get the GOT offset if needed.
2490   // The GOT pointer points to the end of the GOT section.
2491   // We need to subtract the size of the GOT section to get
2492   // the actual offset to use in the relocation.
2493   bool have_got_offset = false;
2494   unsigned int got_offset = 0;
2495   switch (r_type)
2496     {
2497     case elfcpp::R_386_GOT32:
2498       if (gsym != NULL)
2499         {
2500           gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
2501           got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
2502                         - target->got_size());
2503         }
2504       else
2505         {
2506           unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2507           gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
2508           got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
2509                         - target->got_size());
2510         }
2511       have_got_offset = true;
2512       break;
2513
2514     default:
2515       break;
2516     }
2517
2518   switch (r_type)
2519     {
2520     case elfcpp::R_386_NONE:
2521     case elfcpp::R_386_GNU_VTINHERIT:
2522     case elfcpp::R_386_GNU_VTENTRY:
2523       break;
2524
2525     case elfcpp::R_386_32:
2526       if (should_apply_static_reloc(gsym, r_type, true, output_section))
2527         Relocate_functions<32, false>::rel32(view, object, psymval);
2528       break;
2529
2530     case elfcpp::R_386_PC32:
2531       if (should_apply_static_reloc(gsym, r_type, true, output_section))
2532         Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
2533       break;
2534
2535     case elfcpp::R_386_16:
2536       if (should_apply_static_reloc(gsym, r_type, false, output_section))
2537         Relocate_functions<32, false>::rel16(view, object, psymval);
2538       break;
2539
2540     case elfcpp::R_386_PC16:
2541       if (should_apply_static_reloc(gsym, r_type, false, output_section))
2542         Relocate_functions<32, false>::pcrel16(view, object, psymval, address);
2543       break;
2544
2545     case elfcpp::R_386_8:
2546       if (should_apply_static_reloc(gsym, r_type, false, output_section))
2547         Relocate_functions<32, false>::rel8(view, object, psymval);
2548       break;
2549
2550     case elfcpp::R_386_PC8:
2551       if (should_apply_static_reloc(gsym, r_type, false, output_section))
2552         Relocate_functions<32, false>::pcrel8(view, object, psymval, address);
2553       break;
2554
2555     case elfcpp::R_386_PLT32:
2556       gold_assert(gsym == NULL
2557                   || gsym->has_plt_offset()
2558                   || gsym->final_value_is_known()
2559                   || (gsym->is_defined()
2560                       && !gsym->is_from_dynobj()
2561                       && !gsym->is_preemptible()));
2562       Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
2563       break;
2564
2565     case elfcpp::R_386_GOT32:
2566       gold_assert(have_got_offset);
2567       Relocate_functions<32, false>::rel32(view, got_offset);
2568       break;
2569
2570     case elfcpp::R_386_GOTOFF:
2571       {
2572         elfcpp::Elf_types<32>::Elf_Addr value;
2573         value = (psymval->value(object, 0)
2574                  - target->got_plt_section()->address());
2575         Relocate_functions<32, false>::rel32(view, value);
2576       }
2577       break;
2578
2579     case elfcpp::R_386_GOTPC:
2580       {
2581         elfcpp::Elf_types<32>::Elf_Addr value;
2582         value = target->got_plt_section()->address();
2583         Relocate_functions<32, false>::pcrel32(view, value, address);
2584       }
2585       break;
2586
2587     case elfcpp::R_386_COPY:
2588     case elfcpp::R_386_GLOB_DAT:
2589     case elfcpp::R_386_JUMP_SLOT:
2590     case elfcpp::R_386_RELATIVE:
2591     case elfcpp::R_386_IRELATIVE:
2592       // These are outstanding tls relocs, which are unexpected when
2593       // linking.
2594     case elfcpp::R_386_TLS_TPOFF:
2595     case elfcpp::R_386_TLS_DTPMOD32:
2596     case elfcpp::R_386_TLS_DTPOFF32:
2597     case elfcpp::R_386_TLS_TPOFF32:
2598     case elfcpp::R_386_TLS_DESC:
2599       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2600                              _("unexpected reloc %u in object file"),
2601                              r_type);
2602       break;
2603
2604       // These are initial tls relocs, which are expected when
2605       // linking.
2606     case elfcpp::R_386_TLS_GD:             // Global-dynamic
2607     case elfcpp::R_386_TLS_GOTDESC:        // Global-dynamic (from ~oliva url)
2608     case elfcpp::R_386_TLS_DESC_CALL:
2609     case elfcpp::R_386_TLS_LDM:            // Local-dynamic
2610     case elfcpp::R_386_TLS_LDO_32:         // Alternate local-dynamic
2611     case elfcpp::R_386_TLS_IE:             // Initial-exec
2612     case elfcpp::R_386_TLS_IE_32:
2613     case elfcpp::R_386_TLS_GOTIE:
2614     case elfcpp::R_386_TLS_LE:             // Local-exec
2615     case elfcpp::R_386_TLS_LE_32:
2616       this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
2617                          view, address, view_size);
2618       break;
2619
2620     case elfcpp::R_386_32PLT:
2621     case elfcpp::R_386_TLS_GD_32:
2622     case elfcpp::R_386_TLS_GD_PUSH:
2623     case elfcpp::R_386_TLS_GD_CALL:
2624     case elfcpp::R_386_TLS_GD_POP:
2625     case elfcpp::R_386_TLS_LDM_32:
2626     case elfcpp::R_386_TLS_LDM_PUSH:
2627     case elfcpp::R_386_TLS_LDM_CALL:
2628     case elfcpp::R_386_TLS_LDM_POP:
2629     case elfcpp::R_386_USED_BY_INTEL_200:
2630     default:
2631       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2632                              _("unsupported reloc %u"),
2633                              r_type);
2634       break;
2635     }
2636
2637   return true;
2638 }
2639
2640 // Perform a TLS relocation.
2641
2642 inline void
2643 Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo,
2644                                     Target_i386* target,
2645                                     size_t relnum,
2646                                     const elfcpp::Rel<32, false>& rel,
2647                                     unsigned int r_type,
2648                                     const Sized_symbol<32>* gsym,
2649                                     const Symbol_value<32>* psymval,
2650                                     unsigned char* view,
2651                                     elfcpp::Elf_types<32>::Elf_Addr,
2652                                     section_size_type view_size)
2653 {
2654   Output_segment* tls_segment = relinfo->layout->tls_segment();
2655
2656   const Sized_relobj_file<32, false>* object = relinfo->object;
2657
2658   elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
2659
2660   const bool is_final = (gsym == NULL
2661                          ? !parameters->options().shared()
2662                          : gsym->final_value_is_known());
2663   const tls::Tls_optimization optimized_type
2664       = Target_i386::optimize_tls_reloc(is_final, r_type);
2665   switch (r_type)
2666     {
2667     case elfcpp::R_386_TLS_GD:           // Global-dynamic
2668       if (optimized_type == tls::TLSOPT_TO_LE)
2669         {
2670           if (tls_segment == NULL)
2671             {
2672               gold_assert(parameters->errors()->error_count() > 0
2673                           || issue_undefined_symbol_error(gsym));
2674               return;
2675             }
2676           this->tls_gd_to_le(relinfo, relnum, tls_segment,
2677                              rel, r_type, value, view,
2678                              view_size);
2679           break;
2680         }
2681       else
2682         {
2683           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
2684                                    ? GOT_TYPE_TLS_NOFFSET
2685                                    : GOT_TYPE_TLS_PAIR);
2686           unsigned int got_offset;
2687           if (gsym != NULL)
2688             {
2689               gold_assert(gsym->has_got_offset(got_type));
2690               got_offset = gsym->got_offset(got_type) - target->got_size();
2691             }
2692           else
2693             {
2694               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2695               gold_assert(object->local_has_got_offset(r_sym, got_type));
2696               got_offset = (object->local_got_offset(r_sym, got_type)
2697                             - target->got_size());
2698             }
2699           if (optimized_type == tls::TLSOPT_TO_IE)
2700             {
2701               if (tls_segment == NULL)
2702                 {
2703                   gold_assert(parameters->errors()->error_count() > 0
2704                               || issue_undefined_symbol_error(gsym));
2705                   return;
2706                 }
2707               this->tls_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
2708                                  got_offset, view, view_size);
2709               break;
2710             }
2711           else if (optimized_type == tls::TLSOPT_NONE)
2712             {
2713               // Relocate the field with the offset of the pair of GOT
2714               // entries.
2715               Relocate_functions<32, false>::rel32(view, got_offset);
2716               break;
2717             }
2718         }
2719       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2720                              _("unsupported reloc %u"),
2721                              r_type);
2722       break;
2723
2724     case elfcpp::R_386_TLS_GOTDESC:      // Global-dynamic (from ~oliva url)
2725     case elfcpp::R_386_TLS_DESC_CALL:
2726       this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
2727       if (optimized_type == tls::TLSOPT_TO_LE)
2728         {
2729           if (tls_segment == NULL)
2730             {
2731               gold_assert(parameters->errors()->error_count() > 0
2732                           || issue_undefined_symbol_error(gsym));
2733               return;
2734             }
2735           this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
2736                                   rel, r_type, value, view,
2737                                   view_size);
2738           break;
2739         }
2740       else
2741         {
2742           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
2743                                    ? GOT_TYPE_TLS_NOFFSET
2744                                    : GOT_TYPE_TLS_DESC);
2745           unsigned int got_offset = 0;
2746           if (r_type == elfcpp::R_386_TLS_GOTDESC
2747               && optimized_type == tls::TLSOPT_NONE)
2748             {
2749               // We created GOT entries in the .got.tlsdesc portion of
2750               // the .got.plt section, but the offset stored in the
2751               // symbol is the offset within .got.tlsdesc.
2752               got_offset = (target->got_size()
2753                             + target->got_plt_section()->data_size());
2754             }
2755           if (gsym != NULL)
2756             {
2757               gold_assert(gsym->has_got_offset(got_type));
2758               got_offset += gsym->got_offset(got_type) - target->got_size();
2759             }
2760           else
2761             {
2762               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2763               gold_assert(object->local_has_got_offset(r_sym, got_type));
2764               got_offset += (object->local_got_offset(r_sym, got_type)
2765                              - target->got_size());
2766             }
2767           if (optimized_type == tls::TLSOPT_TO_IE)
2768             {
2769               if (tls_segment == NULL)
2770                 {
2771                   gold_assert(parameters->errors()->error_count() > 0
2772                               || issue_undefined_symbol_error(gsym));
2773                   return;
2774                 }
2775               this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
2776                                       got_offset, view, view_size);
2777               break;
2778             }
2779           else if (optimized_type == tls::TLSOPT_NONE)
2780             {
2781               if (r_type == elfcpp::R_386_TLS_GOTDESC)
2782                 {
2783                   // Relocate the field with the offset of the pair of GOT
2784                   // entries.
2785                   Relocate_functions<32, false>::rel32(view, got_offset);
2786                 }
2787               break;
2788             }
2789         }
2790       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2791                              _("unsupported reloc %u"),
2792                              r_type);
2793       break;
2794
2795     case elfcpp::R_386_TLS_LDM:          // Local-dynamic
2796       if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN)
2797         {
2798           gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2799                                  _("both SUN and GNU model "
2800                                    "TLS relocations"));
2801           break;
2802         }
2803       this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
2804       if (optimized_type == tls::TLSOPT_TO_LE)
2805         {
2806           if (tls_segment == NULL)
2807             {
2808               gold_assert(parameters->errors()->error_count() > 0
2809                           || issue_undefined_symbol_error(gsym));
2810               return;
2811             }
2812           this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, r_type,
2813                              value, view, view_size);
2814           break;
2815         }
2816       else if (optimized_type == tls::TLSOPT_NONE)
2817         {
2818           // Relocate the field with the offset of the GOT entry for
2819           // the module index.
2820           unsigned int got_offset;
2821           got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
2822                         - target->got_size());
2823           Relocate_functions<32, false>::rel32(view, got_offset);
2824           break;
2825         }
2826       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2827                              _("unsupported reloc %u"),
2828                              r_type);
2829       break;
2830
2831     case elfcpp::R_386_TLS_LDO_32:       // Alternate local-dynamic
2832       if (optimized_type == tls::TLSOPT_TO_LE)
2833         {
2834           // This reloc can appear in debugging sections, in which
2835           // case we must not convert to local-exec.  We decide what
2836           // to do based on whether the section is marked as
2837           // containing executable code.  That is what the GNU linker
2838           // does as well.
2839           elfcpp::Shdr<32, false> shdr(relinfo->data_shdr);
2840           if ((shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0)
2841             {
2842               if (tls_segment == NULL)
2843                 {
2844                   gold_assert(parameters->errors()->error_count() > 0
2845                               || issue_undefined_symbol_error(gsym));
2846                   return;
2847                 }
2848               value -= tls_segment->memsz();
2849             }
2850         }
2851       Relocate_functions<32, false>::rel32(view, value);
2852       break;
2853
2854     case elfcpp::R_386_TLS_IE:           // Initial-exec
2855     case elfcpp::R_386_TLS_GOTIE:
2856     case elfcpp::R_386_TLS_IE_32:
2857       if (optimized_type == tls::TLSOPT_TO_LE)
2858         {
2859           if (tls_segment == NULL)
2860             {
2861               gold_assert(parameters->errors()->error_count() > 0
2862                           || issue_undefined_symbol_error(gsym));
2863               return;
2864             }
2865           Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
2866                                               rel, r_type, value, view,
2867                                               view_size);
2868           break;
2869         }
2870       else if (optimized_type == tls::TLSOPT_NONE)
2871         {
2872           // Relocate the field with the offset of the GOT entry for
2873           // the tp-relative offset of the symbol.
2874           unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
2875                                    ? GOT_TYPE_TLS_OFFSET
2876                                    : GOT_TYPE_TLS_NOFFSET);
2877           unsigned int got_offset;
2878           if (gsym != NULL)
2879             {
2880               gold_assert(gsym->has_got_offset(got_type));
2881               got_offset = gsym->got_offset(got_type);
2882             }
2883           else
2884             {
2885               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2886               gold_assert(object->local_has_got_offset(r_sym, got_type));
2887               got_offset = object->local_got_offset(r_sym, got_type);
2888             }
2889           // For the R_386_TLS_IE relocation, we need to apply the
2890           // absolute address of the GOT entry.
2891           if (r_type == elfcpp::R_386_TLS_IE)
2892             got_offset += target->got_plt_section()->address();
2893           // All GOT offsets are relative to the end of the GOT.
2894           got_offset -= target->got_size();
2895           Relocate_functions<32, false>::rel32(view, got_offset);
2896           break;
2897         }
2898       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2899                              _("unsupported reloc %u"),
2900                              r_type);
2901       break;
2902
2903     case elfcpp::R_386_TLS_LE:           // Local-exec
2904       // If we're creating a shared library, a dynamic relocation will
2905       // have been created for this location, so do not apply it now.
2906       if (!parameters->options().shared())
2907         {
2908           if (tls_segment == NULL)
2909             {
2910               gold_assert(parameters->errors()->error_count() > 0
2911                           || issue_undefined_symbol_error(gsym));
2912               return;
2913             }
2914           value -= tls_segment->memsz();
2915           Relocate_functions<32, false>::rel32(view, value);
2916         }
2917       break;
2918
2919     case elfcpp::R_386_TLS_LE_32:
2920       // If we're creating a shared library, a dynamic relocation will
2921       // have been created for this location, so do not apply it now.
2922       if (!parameters->options().shared())
2923         {
2924           if (tls_segment == NULL)
2925             {
2926               gold_assert(parameters->errors()->error_count() > 0
2927                           || issue_undefined_symbol_error(gsym));
2928               return;
2929             }
2930           value = tls_segment->memsz() - value;
2931           Relocate_functions<32, false>::rel32(view, value);
2932         }
2933       break;
2934     }
2935 }
2936
2937 // Do a relocation in which we convert a TLS General-Dynamic to a
2938 // Local-Exec.
2939
2940 inline void
2941 Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo,
2942                                     size_t relnum,
2943                                     Output_segment* tls_segment,
2944                                     const elfcpp::Rel<32, false>& rel,
2945                                     unsigned int,
2946                                     elfcpp::Elf_types<32>::Elf_Addr value,
2947                                     unsigned char* view,
2948                                     section_size_type view_size)
2949 {
2950   // leal foo(,%reg,1),%eax; call ___tls_get_addr
2951   //  ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2952   // leal foo(%reg),%eax; call ___tls_get_addr
2953   //  ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2954
2955   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2956   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2957
2958   unsigned char op1 = view[-1];
2959   unsigned char op2 = view[-2];
2960
2961   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2962                  op2 == 0x8d || op2 == 0x04);
2963   tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2964
2965   int roff = 5;
2966
2967   if (op2 == 0x04)
2968     {
2969       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
2970       tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
2971       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2972                      ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
2973       memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2974     }
2975   else
2976     {
2977       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2978                      (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
2979       if (rel.get_r_offset() + 9 < view_size
2980           && view[9] == 0x90)
2981         {
2982           // There is a trailing nop.  Use the size byte subl.
2983           memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2984           roff = 6;
2985         }
2986       else
2987         {
2988           // Use the five byte subl.
2989           memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2990         }
2991     }
2992
2993   value = tls_segment->memsz() - value;
2994   Relocate_functions<32, false>::rel32(view + roff, value);
2995
2996   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2997   // We can skip it.
2998   this->skip_call_tls_get_addr_ = true;
2999 }
3000
3001 // Do a relocation in which we convert a TLS General-Dynamic to an
3002 // Initial-Exec.
3003
3004 inline void
3005 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info<32, false>* relinfo,
3006                                     size_t relnum,
3007                                     Output_segment*,
3008                                     const elfcpp::Rel<32, false>& rel,
3009                                     unsigned int,
3010                                     elfcpp::Elf_types<32>::Elf_Addr value,
3011                                     unsigned char* view,
3012                                     section_size_type view_size)
3013 {
3014   // leal foo(,%ebx,1),%eax; call ___tls_get_addr
3015   //  ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
3016
3017   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3018   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
3019
3020   unsigned char op1 = view[-1];
3021   unsigned char op2 = view[-2];
3022
3023   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3024                  op2 == 0x8d || op2 == 0x04);
3025   tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
3026
3027   int roff = 5;
3028
3029   // FIXME: For now, support only the first (SIB) form.
3030   tls::check_tls(relinfo, relnum, rel.get_r_offset(), op2 == 0x04);
3031
3032   if (op2 == 0x04)
3033     {
3034       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
3035       tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
3036       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3037                      ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
3038       memcpy(view - 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
3039     }
3040   else
3041     {
3042       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3043                      (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
3044       if (rel.get_r_offset() + 9 < view_size
3045           && view[9] == 0x90)
3046         {
3047           // FIXME: This is not the right instruction sequence.
3048           // There is a trailing nop.  Use the size byte subl.
3049           memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3050           roff = 6;
3051         }
3052       else
3053         {
3054           // FIXME: This is not the right instruction sequence.
3055           // Use the five byte subl.
3056           memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
3057         }
3058     }
3059
3060   Relocate_functions<32, false>::rel32(view + roff, value);
3061
3062   // The next reloc should be a PLT32 reloc against __tls_get_addr.
3063   // We can skip it.
3064   this->skip_call_tls_get_addr_ = true;
3065 }
3066
3067 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3068 // General-Dynamic to a Local-Exec.
3069
3070 inline void
3071 Target_i386::Relocate::tls_desc_gd_to_le(
3072     const Relocate_info<32, false>* relinfo,
3073     size_t relnum,
3074     Output_segment* tls_segment,
3075     const elfcpp::Rel<32, false>& rel,
3076     unsigned int r_type,
3077     elfcpp::Elf_types<32>::Elf_Addr value,
3078     unsigned char* view,
3079     section_size_type view_size)
3080 {
3081   if (r_type == elfcpp::R_386_TLS_GOTDESC)
3082     {
3083       // leal foo@TLSDESC(%ebx), %eax
3084       // ==> leal foo@NTPOFF, %eax
3085       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3086       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3087       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3088                      view[-2] == 0x8d && view[-1] == 0x83);
3089       view[-1] = 0x05;
3090       value -= tls_segment->memsz();
3091       Relocate_functions<32, false>::rel32(view, value);
3092     }
3093   else
3094     {
3095       // call *foo@TLSCALL(%eax)
3096       // ==> nop; nop
3097       gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
3098       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
3099       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3100                      view[0] == 0xff && view[1] == 0x10);
3101       view[0] = 0x66;
3102       view[1] = 0x90;
3103     }
3104 }
3105
3106 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3107 // General-Dynamic to an Initial-Exec.
3108
3109 inline void
3110 Target_i386::Relocate::tls_desc_gd_to_ie(
3111     const Relocate_info<32, false>* relinfo,
3112     size_t relnum,
3113     Output_segment*,
3114     const elfcpp::Rel<32, false>& rel,
3115     unsigned int r_type,
3116     elfcpp::Elf_types<32>::Elf_Addr value,
3117     unsigned char* view,
3118     section_size_type view_size)
3119 {
3120   if (r_type == elfcpp::R_386_TLS_GOTDESC)
3121     {
3122       // leal foo@TLSDESC(%ebx), %eax
3123       // ==> movl foo@GOTNTPOFF(%ebx), %eax
3124       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3125       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3126       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3127                      view[-2] == 0x8d && view[-1] == 0x83);
3128       view[-2] = 0x8b;
3129       Relocate_functions<32, false>::rel32(view, value);
3130     }
3131   else
3132     {
3133       // call *foo@TLSCALL(%eax)
3134       // ==> nop; nop
3135       gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
3136       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
3137       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3138                      view[0] == 0xff && view[1] == 0x10);
3139       view[0] = 0x66;
3140       view[1] = 0x90;
3141     }
3142 }
3143
3144 // Do a relocation in which we convert a TLS Local-Dynamic to a
3145 // Local-Exec.
3146
3147 inline void
3148 Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo,
3149                                     size_t relnum,
3150                                     Output_segment*,
3151                                     const elfcpp::Rel<32, false>& rel,
3152                                     unsigned int,
3153                                     elfcpp::Elf_types<32>::Elf_Addr,
3154                                     unsigned char* view,
3155                                     section_size_type view_size)
3156 {
3157   // leal foo(%reg), %eax; call ___tls_get_addr
3158   // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
3159
3160   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3161   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
3162
3163   // FIXME: Does this test really always pass?
3164   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3165                  view[-2] == 0x8d && view[-1] == 0x83);
3166
3167   tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
3168
3169   memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
3170
3171   // The next reloc should be a PLT32 reloc against __tls_get_addr.
3172   // We can skip it.
3173   this->skip_call_tls_get_addr_ = true;
3174 }
3175
3176 // Do a relocation in which we convert a TLS Initial-Exec to a
3177 // Local-Exec.
3178
3179 inline void
3180 Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo,
3181                                     size_t relnum,
3182                                     Output_segment* tls_segment,
3183                                     const elfcpp::Rel<32, false>& rel,
3184                                     unsigned int r_type,
3185                                     elfcpp::Elf_types<32>::Elf_Addr value,
3186                                     unsigned char* view,
3187                                     section_size_type view_size)
3188 {
3189   // We have to actually change the instructions, which means that we
3190   // need to examine the opcodes to figure out which instruction we
3191   // are looking at.
3192   if (r_type == elfcpp::R_386_TLS_IE)
3193     {
3194       // movl %gs:XX,%eax  ==>  movl $YY,%eax
3195       // movl %gs:XX,%reg  ==>  movl $YY,%reg
3196       // addl %gs:XX,%reg  ==>  addl $YY,%reg
3197       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -1);
3198       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3199
3200       unsigned char op1 = view[-1];
3201       if (op1 == 0xa1)
3202         {
3203           // movl XX,%eax  ==>  movl $YY,%eax
3204           view[-1] = 0xb8;
3205         }
3206       else
3207         {
3208           tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3209
3210           unsigned char op2 = view[-2];
3211           if (op2 == 0x8b)
3212             {
3213               // movl XX,%reg  ==>  movl $YY,%reg
3214               tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3215                              (op1 & 0xc7) == 0x05);
3216               view[-2] = 0xc7;
3217               view[-1] = 0xc0 | ((op1 >> 3) & 7);
3218             }
3219           else if (op2 == 0x03)
3220             {
3221               // addl XX,%reg  ==>  addl $YY,%reg
3222               tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3223                              (op1 & 0xc7) == 0x05);
3224               view[-2] = 0x81;
3225               view[-1] = 0xc0 | ((op1 >> 3) & 7);
3226             }
3227           else
3228             tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
3229         }
3230     }
3231   else
3232     {
3233       // subl %gs:XX(%reg1),%reg2  ==>  subl $YY,%reg2
3234       // movl %gs:XX(%reg1),%reg2  ==>  movl $YY,%reg2
3235       // addl %gs:XX(%reg1),%reg2  ==>  addl $YY,$reg2
3236       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3237       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3238
3239       unsigned char op1 = view[-1];
3240       unsigned char op2 = view[-2];
3241       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3242                      (op1 & 0xc0) == 0x80 && (op1 & 7) != 4);
3243       if (op2 == 0x8b)
3244         {
3245           // movl %gs:XX(%reg1),%reg2  ==>  movl $YY,%reg2
3246           view[-2] = 0xc7;
3247           view[-1] = 0xc0 | ((op1 >> 3) & 7);
3248         }
3249       else if (op2 == 0x2b)
3250         {
3251           // subl %gs:XX(%reg1),%reg2  ==>  subl $YY,%reg2
3252           view[-2] = 0x81;
3253           view[-1] = 0xe8 | ((op1 >> 3) & 7);
3254         }
3255       else if (op2 == 0x03)
3256         {
3257           // addl %gs:XX(%reg1),%reg2  ==>  addl $YY,$reg2
3258           view[-2] = 0x81;
3259           view[-1] = 0xc0 | ((op1 >> 3) & 7);
3260         }
3261       else
3262         tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
3263     }
3264
3265   value = tls_segment->memsz() - value;
3266   if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE)
3267     value = - value;
3268
3269   Relocate_functions<32, false>::rel32(view, value);
3270 }
3271
3272 // Relocate section data.
3273
3274 void
3275 Target_i386::relocate_section(const Relocate_info<32, false>* relinfo,
3276                               unsigned int sh_type,
3277                               const unsigned char* prelocs,
3278                               size_t reloc_count,
3279                               Output_section* output_section,
3280                               bool needs_special_offset_handling,
3281                               unsigned char* view,
3282                               elfcpp::Elf_types<32>::Elf_Addr address,
3283                               section_size_type view_size,
3284                               const Reloc_symbol_changes* reloc_symbol_changes)
3285 {
3286   gold_assert(sh_type == elfcpp::SHT_REL);
3287
3288   gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL,
3289                          Target_i386::Relocate>(
3290     relinfo,
3291     this,
3292     prelocs,
3293     reloc_count,
3294     output_section,
3295     needs_special_offset_handling,
3296     view,
3297     address,
3298     view_size,
3299     reloc_symbol_changes);
3300 }
3301
3302 // Return the size of a relocation while scanning during a relocatable
3303 // link.
3304
3305 unsigned int
3306 Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
3307     unsigned int r_type,
3308     Relobj* object)
3309 {
3310   switch (r_type)
3311     {
3312     case elfcpp::R_386_NONE:
3313     case elfcpp::R_386_GNU_VTINHERIT:
3314     case elfcpp::R_386_GNU_VTENTRY:
3315     case elfcpp::R_386_TLS_GD:            // Global-dynamic
3316     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
3317     case elfcpp::R_386_TLS_DESC_CALL:
3318     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
3319     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
3320     case elfcpp::R_386_TLS_IE:            // Initial-exec
3321     case elfcpp::R_386_TLS_IE_32:
3322     case elfcpp::R_386_TLS_GOTIE:
3323     case elfcpp::R_386_TLS_LE:            // Local-exec
3324     case elfcpp::R_386_TLS_LE_32:
3325       return 0;
3326
3327     case elfcpp::R_386_32:
3328     case elfcpp::R_386_PC32:
3329     case elfcpp::R_386_GOT32:
3330     case elfcpp::R_386_PLT32:
3331     case elfcpp::R_386_GOTOFF:
3332     case elfcpp::R_386_GOTPC:
3333      return 4;
3334
3335     case elfcpp::R_386_16:
3336     case elfcpp::R_386_PC16:
3337       return 2;
3338
3339     case elfcpp::R_386_8:
3340     case elfcpp::R_386_PC8:
3341       return 1;
3342
3343       // These are relocations which should only be seen by the
3344       // dynamic linker, and should never be seen here.
3345     case elfcpp::R_386_COPY:
3346     case elfcpp::R_386_GLOB_DAT:
3347     case elfcpp::R_386_JUMP_SLOT:
3348     case elfcpp::R_386_RELATIVE:
3349     case elfcpp::R_386_IRELATIVE:
3350     case elfcpp::R_386_TLS_TPOFF:
3351     case elfcpp::R_386_TLS_DTPMOD32:
3352     case elfcpp::R_386_TLS_DTPOFF32:
3353     case elfcpp::R_386_TLS_TPOFF32:
3354     case elfcpp::R_386_TLS_DESC:
3355       object->error(_("unexpected reloc %u in object file"), r_type);
3356       return 0;
3357
3358     case elfcpp::R_386_32PLT:
3359     case elfcpp::R_386_TLS_GD_32:
3360     case elfcpp::R_386_TLS_GD_PUSH:
3361     case elfcpp::R_386_TLS_GD_CALL:
3362     case elfcpp::R_386_TLS_GD_POP:
3363     case elfcpp::R_386_TLS_LDM_32:
3364     case elfcpp::R_386_TLS_LDM_PUSH:
3365     case elfcpp::R_386_TLS_LDM_CALL:
3366     case elfcpp::R_386_TLS_LDM_POP:
3367     case elfcpp::R_386_USED_BY_INTEL_200:
3368     default:
3369       object->error(_("unsupported reloc %u in object file"), r_type);
3370       return 0;
3371     }
3372 }
3373
3374 // Scan the relocs during a relocatable link.
3375
3376 void
3377 Target_i386::scan_relocatable_relocs(Symbol_table* symtab,
3378                                      Layout* layout,
3379                                      Sized_relobj_file<32, false>* object,
3380                                      unsigned int data_shndx,
3381                                      unsigned int sh_type,
3382                                      const unsigned char* prelocs,
3383                                      size_t reloc_count,
3384                                      Output_section* output_section,
3385                                      bool needs_special_offset_handling,
3386                                      size_t local_symbol_count,
3387                                      const unsigned char* plocal_symbols,
3388                                      Relocatable_relocs* rr)
3389 {
3390   gold_assert(sh_type == elfcpp::SHT_REL);
3391
3392   typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_REL,
3393     Relocatable_size_for_reloc> Scan_relocatable_relocs;
3394
3395   gold::scan_relocatable_relocs<32, false, elfcpp::SHT_REL,
3396       Scan_relocatable_relocs>(
3397     symtab,
3398     layout,
3399     object,
3400     data_shndx,
3401     prelocs,
3402     reloc_count,
3403     output_section,
3404     needs_special_offset_handling,
3405     local_symbol_count,
3406     plocal_symbols,
3407     rr);
3408 }
3409
3410 // Relocate a section during a relocatable link.
3411
3412 void
3413 Target_i386::relocate_for_relocatable(
3414     const Relocate_info<32, false>* relinfo,
3415     unsigned int sh_type,
3416     const unsigned char* prelocs,
3417     size_t reloc_count,
3418     Output_section* output_section,
3419     off_t offset_in_output_section,
3420     const Relocatable_relocs* rr,
3421     unsigned char* view,
3422     elfcpp::Elf_types<32>::Elf_Addr view_address,
3423     section_size_type view_size,
3424     unsigned char* reloc_view,
3425     section_size_type reloc_view_size)
3426 {
3427   gold_assert(sh_type == elfcpp::SHT_REL);
3428
3429   gold::relocate_for_relocatable<32, false, elfcpp::SHT_REL>(
3430     relinfo,
3431     prelocs,
3432     reloc_count,
3433     output_section,
3434     offset_in_output_section,
3435     rr,
3436     view,
3437     view_address,
3438     view_size,
3439     reloc_view,
3440     reloc_view_size);
3441 }
3442
3443 // Return the value to use for a dynamic which requires special
3444 // treatment.  This is how we support equality comparisons of function
3445 // pointers across shared library boundaries, as described in the
3446 // processor specific ABI supplement.
3447
3448 uint64_t
3449 Target_i386::do_dynsym_value(const Symbol* gsym) const
3450 {
3451   gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
3452   return this->plt_address_for_global(gsym) + gsym->plt_offset();
3453 }
3454
3455 // Return a string used to fill a code section with nops to take up
3456 // the specified length.
3457
3458 std::string
3459 Target_i386::do_code_fill(section_size_type length) const
3460 {
3461   if (length >= 16)
3462     {
3463       // Build a jmp instruction to skip over the bytes.
3464       unsigned char jmp[5];
3465       jmp[0] = 0xe9;
3466       elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
3467       return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
3468               + std::string(length - 5, '\0'));
3469     }
3470
3471   // Nop sequences of various lengths.
3472   const char nop1[1] = { 0x90 };                   // nop
3473   const char nop2[2] = { 0x66, 0x90 };             // xchg %ax %ax
3474   const char nop3[3] = { 0x8d, 0x76, 0x00 };       // leal 0(%esi),%esi
3475   const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00};  // leal 0(%esi,1),%esi
3476   const char nop5[5] = { 0x90, 0x8d, 0x74, 0x26,   // nop
3477                          0x00 };                   // leal 0(%esi,1),%esi
3478   const char nop6[6] = { 0x8d, 0xb6, 0x00, 0x00,   // leal 0L(%esi),%esi
3479                          0x00, 0x00 };
3480   const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00,   // leal 0L(%esi,1),%esi
3481                          0x00, 0x00, 0x00 };
3482   const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26,   // nop
3483                          0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
3484   const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc,   // movl %esi,%esi
3485                          0x27, 0x00, 0x00, 0x00,   // leal 0L(%edi,1),%edi
3486                          0x00 };
3487   const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
3488                            0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
3489                            0x00, 0x00 };
3490   const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
3491                            0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
3492                            0x00, 0x00, 0x00 };
3493   const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
3494                            0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
3495                            0x00, 0x00, 0x00, 0x00 };
3496   const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
3497                            0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
3498                            0x27, 0x00, 0x00, 0x00,
3499                            0x00 };
3500   const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
3501                            0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
3502                            0xbc, 0x27, 0x00, 0x00,
3503                            0x00, 0x00 };
3504   const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
3505                            0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
3506                            0x90, 0x90, 0x90, 0x90,
3507                            0x90, 0x90, 0x90 };
3508
3509   const char* nops[16] = {
3510     NULL,
3511     nop1, nop2, nop3, nop4, nop5, nop6, nop7,
3512     nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
3513   };
3514
3515   return std::string(nops[length], length);
3516 }
3517
3518 // Return the value to use for the base of a DW_EH_PE_datarel offset
3519 // in an FDE.  Solaris and SVR4 use DW_EH_PE_datarel because their
3520 // assembler can not write out the difference between two labels in
3521 // different sections, so instead of using a pc-relative value they
3522 // use an offset from the GOT.
3523
3524 uint64_t
3525 Target_i386::do_ehframe_datarel_base() const
3526 {
3527   gold_assert(this->global_offset_table_ != NULL);
3528   Symbol* sym = this->global_offset_table_;
3529   Sized_symbol<32>* ssym = static_cast<Sized_symbol<32>*>(sym);
3530   return ssym->value();
3531 }
3532
3533 // Return whether SYM should be treated as a call to a non-split
3534 // function.  We don't want that to be true of a call to a
3535 // get_pc_thunk function.
3536
3537 bool
3538 Target_i386::do_is_call_to_non_split(const Symbol* sym, unsigned int) const
3539 {
3540   return (sym->type() == elfcpp::STT_FUNC
3541           && !is_prefix_of("__i686.get_pc_thunk.", sym->name()));
3542 }
3543
3544 // FNOFFSET in section SHNDX in OBJECT is the start of a function
3545 // compiled with -fsplit-stack.  The function calls non-split-stack
3546 // code.  We have to change the function so that it always ensures
3547 // that it has enough stack space to run some random function.
3548
3549 void
3550 Target_i386::do_calls_non_split(Relobj* object, unsigned int shndx,
3551                                 section_offset_type fnoffset,
3552                                 section_size_type fnsize,
3553                                 unsigned char* view,
3554                                 section_size_type view_size,
3555                                 std::string* from,
3556                                 std::string* to) const
3557 {
3558   // The function starts with a comparison of the stack pointer and a
3559   // field in the TCB.  This is followed by a jump.
3560
3561   // cmp %gs:NN,%esp
3562   if (this->match_view(view, view_size, fnoffset, "\x65\x3b\x25", 3)
3563       && fnsize > 7)
3564     {
3565       // We will call __morestack if the carry flag is set after this
3566       // comparison.  We turn the comparison into an stc instruction
3567       // and some nops.
3568       view[fnoffset] = '\xf9';
3569       this->set_view_to_nop(view, view_size, fnoffset + 1, 6);
3570     }
3571   // lea NN(%esp),%ecx
3572   // lea NN(%esp),%edx
3573   else if ((this->match_view(view, view_size, fnoffset, "\x8d\x8c\x24", 3)
3574             || this->match_view(view, view_size, fnoffset, "\x8d\x94\x24", 3))
3575            && fnsize > 7)
3576     {
3577       // This is loading an offset from the stack pointer for a
3578       // comparison.  The offset is negative, so we decrease the
3579       // offset by the amount of space we need for the stack.  This
3580       // means we will avoid calling __morestack if there happens to
3581       // be plenty of space on the stack already.
3582       unsigned char* pval = view + fnoffset + 3;
3583       uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
3584       val -= parameters->options().split_stack_adjust_size();
3585       elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
3586     }
3587   else
3588     {
3589       if (!object->has_no_split_stack())
3590         object->error(_("failed to match split-stack sequence at "
3591                         "section %u offset %0zx"),
3592                       shndx, static_cast<size_t>(fnoffset));
3593       return;
3594     }
3595
3596   // We have to change the function so that it calls
3597   // __morestack_non_split instead of __morestack.  The former will
3598   // allocate additional stack space.
3599   *from = "__morestack";
3600   *to = "__morestack_non_split";
3601 }
3602
3603 // The selector for i386 object files.
3604
3605 class Target_selector_i386 : public Target_selector_freebsd
3606 {
3607 public:
3608   Target_selector_i386()
3609     : Target_selector_freebsd(elfcpp::EM_386, 32, false,
3610                               "elf32-i386", "elf32-i386-freebsd",
3611                               "elf_i386")
3612   { }
3613
3614   Target*
3615   do_instantiate_target()
3616   { return new Target_i386(); }
3617 };
3618
3619 Target_selector_i386 target_selector_i386;
3620
3621 } // End anonymous namespace.