[deliverable/binutils-gdb.git] / gold / resolve.cc

// resolve.cc -- symbol resolution for gold

#include "gold.h"

#include "elfcpp.h"
#include "target.h"
#include "object.h"
#include "symtab.h"

namespace gold
{

// Symbol methods used in this file.

// Override the fields in Symbol.

template<int size, bool big_endian>
void
Symbol::override_base(const elfcpp::Sym<size, big_endian>& sym,
		      Object* object)
{
  this->object_ = object;
  this->shnum_ = sym.get_st_shndx(); // FIXME: Handle SHN_XINDEX.
  this->type_ = sym.get_st_type();
  this->binding_ = sym.get_st_bind();
  this->visibility_ = sym.get_st_visibility();
  this->other_ = sym.get_st_nonvis();
}

// Override the fields in Sized_symbol.

template<int size>
template<bool big_endian>
void
Sized_symbol<size>::override(const elfcpp::Sym<size, big_endian>& sym,
			     Object* object)
{
  this->override_base(sym, object);
  this->value_ = sym.get_st_value();
  this->size_ = sym.get_st_size();
}

// Resolve a symbol.  This is called the second and subsequent times
// we see a symbol.  TO is the pre-existing symbol.  SYM is the new
// symbol, seen in OBJECT.

template<int size, bool big_endian>
void
Symbol_table::resolve(Sized_symbol<size>* to,
		      const elfcpp::Sym<size, big_endian>& sym,
		      Object* object)
{
  if (object->target()->has_resolve())
    {
      object->sized_target<size, big_endian>()->resolve(to, sym, object);
      return;
    }

  // Build a little code for each symbol.
  // Bit 0: 0 for global, 1 for weak.
  // Bit 1: 0 for regular object, 1 for shared object
  // Bits 2-3: 0 for normal, 1 for undefined, 2 for common
  // This gives us values from 0 to 11:

  enum
  {
    DEF = 0,
    WEAK_DEF = 1,
    DYN_DEF = 2,
    DYN_WEAK_DEF = 3,
    UNDEF = 4,
    WEAK_UNDEF = 5,
    DYN_UNDEF = 6,
    DYN_WEAK_UNDEF = 7,
    COMMON = 8,
    WEAK_COMMON = 9,
    DYN_COMMON = 10,
    DYN_WEAK_COMMON = 11
  };

  int tobits;
  switch (to->binding())
    {
    case elfcpp::STB_GLOBAL:
      tobits = 0;
      break;

    case elfcpp::STB_WEAK:
      tobits = 1;
      break;

    case elfcpp::STB_LOCAL:
      // We should only see externally visible symbols in the symbol
      // table.
      abort();

    default:
      // Any target which wants to handle STB_LOOS, etc., needs to
      // define a resolve method.
      abort();
    }

  if (to->object() != NULL && to->object()->is_dynamic())
    tobits |= (1 << 1);

  switch (to->shnum())
    {
    case elfcpp::SHN_UNDEF:
      tobits |= (1 << 2);
      break;

    case elfcpp::SHN_COMMON:
      tobits |= (2 << 2);
      break;

    default:
      if (to->type() == elfcpp::STT_COMMON)
	tobits |= (2 << 2);
      break;
    }

  int frombits;
  switch (sym.get_st_bind())
    {
    case elfcpp::STB_GLOBAL:
      frombits = 0;
      break;

    case elfcpp::STB_WEAK:
      frombits = 1;
      break;

    case elfcpp::STB_LOCAL:
      fprintf(stderr,
	      _("%s: %s: invalid STB_LOCAL symbol %s in external symbols\n"),
	      program_name, object->name().c_str(), to->name());
      gold_exit(false);

    default:
      fprintf(stderr,
	      _("%s: %s: unsupported symbol binding %d for symbol %s\n"),
	      program_name, object->name().c_str(),
	      static_cast<int>(sym.get_st_bind()), to->name());
      gold_exit(false);
    }

  if (object->is_dynamic())
    {
      frombits |= (1 << 1);

      // Record that we've seen this symbol in a dynamic object.
      to->set_in_dyn();
    }

  switch (sym.get_st_shndx())
    {
    case elfcpp::SHN_UNDEF:
      frombits |= (1 << 2);
      break;

    case elfcpp::SHN_COMMON:
      frombits |= (2 << 2);
      break;

    default:
      if (sym.get_st_type() == elfcpp::STT_COMMON)
	frombits |= (2 << 2);
      break;
    }

  // FIXME: Warn if either but not both of TO and SYM are STT_TLS.

  // We use a giant switch table for symbol resolution.  This code is
  // unwieldy, but: 1) it is efficient; 2) we definitely handle all
  // cases; 3) it is easy to change the handling of a particular case.
  // The alternative would be a series of conditionals, but it is easy
  // to get the ordering wrong.  This could also be done as a table,
  // but that is no easier to understand than this large switch
  // statement.

  switch (tobits * 16 + frombits)
    {
    case DEF * 16 + DEF:
      // Two definitions of the same symbol.
      fprintf(stderr, "%s: %s: multiple definition of %s\n",
	      program_name, object->name().c_str(), to->name());
      // FIXME: Report locations.  Record that we have seen an error.
      return;

    case WEAK_DEF * 16 + DEF:
      // We've seen a weak definition, and now we see a strong
      // definition.  In the original SVR4 linker, this was treated as
      // a multiple definition error.  In the Solaris linker and the
      // GNU linker, a weak definition followed by a regular
      // definition causes the weak definition to be overridden.  We
      // are currently compatible with the GNU linker.  In the future
      // we should add a target specific option to change this.
      // FIXME.
      to->override(sym, object);
      return;

    case DYN_DEF * 16 + DEF:
    case DYN_WEAK_DEF * 16 + DEF:
      // We've seen a definition in a dynamic object, and now we see a
      // definition in a regular object.  The definition in the
      // regular object overrides the definition in the dynamic
      // object.
      to->override(sym, object);
      return;

    case UNDEF * 16 + DEF:
    case WEAK_UNDEF * 16 + DEF:
    case DYN_UNDEF * 16 + DEF:
    case DYN_WEAK_UNDEF * 16 + DEF:
      // We've seen an undefined reference, and now we see a
      // definition.  We use the definition.
      to->override(sym, object);
      return;

    case COMMON * 16 + DEF:
    case WEAK_COMMON * 16 + DEF:
    case DYN_COMMON * 16 + DEF:
    case DYN_WEAK_COMMON * 16 + DEF:
      // We've seen a common symbol and now we see a definition.  The
      // definition overrides.  FIXME: We should optionally issue a
      // warning.
      to->override(sym, object);
      return;

    case DEF * 16 + WEAK_DEF:
    case WEAK_DEF * 16 + WEAK_DEF:
      // We've seen a definition and now we see a weak definition.  We
      // ignore the new weak definition.
      return;

    case DYN_DEF * 16 + WEAK_DEF:
    case DYN_WEAK_DEF * 16 + WEAK_DEF:
      // We've seen a dynamic definition and now we see a regular weak
      // definition.  The regular weak definition overrides.
      to->override(sym, object);
      return;

    case UNDEF * 16 + WEAK_DEF:
    case WEAK_UNDEF * 16 + WEAK_DEF:
    case DYN_UNDEF * 16 + WEAK_DEF:
    case DYN_WEAK_UNDEF * 16 + WEAK_DEF:
      // A weak definition of a currently undefined symbol.
      to->override(sym, object);
      return;

    case COMMON * 16 + WEAK_DEF:
    case WEAK_COMMON * 16 + WEAK_DEF:
      // A weak definition does not override a common definition.
      return;

    case DYN_COMMON * 16 + WEAK_DEF:
    case DYN_WEAK_COMMON * 16 + WEAK_DEF:
      // A weak definition does override a definition in a dynamic
      // object.  FIXME: We should optionally issue a warning.
      to->override(sym, object);
      return;

    case DEF * 16 + DYN_DEF:
    case WEAK_DEF * 16 + DYN_DEF:
    case DYN_DEF * 16 + DYN_DEF:
    case DYN_WEAK_DEF * 16 + DYN_DEF:
      // Ignore a dynamic definition if we already have a definition.
      return;

    case UNDEF * 16 + DYN_DEF:
    case WEAK_UNDEF * 16 + DYN_DEF:
    case DYN_UNDEF * 16 + DYN_DEF:
    case DYN_WEAK_UNDEF * 16 + DYN_DEF:
      // Use a dynamic definition if we have a reference.
      to->override(sym, object);
      return;

    case COMMON * 16 + DYN_DEF:
    case WEAK_COMMON * 16 + DYN_DEF:
    case DYN_COMMON * 16 + DYN_DEF:
    case DYN_WEAK_COMMON * 16 + DYN_DEF:
      // Ignore a dynamic definition if we already have a common
      // definition.
      return;

    case DEF * 16 + DYN_WEAK_DEF:
    case WEAK_DEF * 16 + DYN_WEAK_DEF:
    case DYN_DEF * 16 + DYN_WEAK_DEF:
    case DYN_WEAK_DEF * 16 + DYN_WEAK_DEF:
      // Ignore a weak dynamic definition if we already have a
      // definition.
      return;

    case UNDEF * 16 + DYN_WEAK_DEF:
    case WEAK_UNDEF * 16 + DYN_WEAK_DEF:
    case DYN_UNDEF * 16 + DYN_WEAK_DEF:
    case DYN_WEAK_UNDEF * 16 + DYN_WEAK_DEF:
      // Use a weak dynamic definition if we have a reference.
      to->override(sym, object);
      return;

    case COMMON * 16 + DYN_WEAK_DEF:
    case WEAK_COMMON * 16 + DYN_WEAK_DEF:
    case DYN_COMMON * 16 + DYN_WEAK_DEF:
    case DYN_WEAK_COMMON * 16 + DYN_WEAK_DEF:
      // Ignore a weak dynamic definition if we already have a common
      // definition.
      return;

    case DEF * 16 + UNDEF:
    case WEAK_DEF * 16 + UNDEF:
    case DYN_DEF * 16 + UNDEF:
    case DYN_WEAK_DEF * 16 + UNDEF:
    case UNDEF * 16 + UNDEF:
    case WEAK_UNDEF * 16 + UNDEF:
    case DYN_UNDEF * 16 + UNDEF:
    case DYN_WEAK_UNDEF * 16 + UNDEF:
    case COMMON * 16 + UNDEF:
    case WEAK_COMMON * 16 + UNDEF:
    case DYN_COMMON * 16 + UNDEF:
    case DYN_WEAK_COMMON * 16 + UNDEF:
      // A new undefined reference tells us nothing.
      return;

    case DEF * 16 + WEAK_UNDEF:
    case WEAK_DEF * 16 + WEAK_UNDEF:
    case DYN_DEF * 16 + WEAK_UNDEF:
    case DYN_WEAK_DEF * 16 + WEAK_UNDEF:
    case UNDEF * 16 + WEAK_UNDEF:
    case WEAK_UNDEF * 16 + WEAK_UNDEF:
    case DYN_UNDEF * 16 + WEAK_UNDEF:
    case DYN_WEAK_UNDEF * 16 + WEAK_UNDEF:
    case COMMON * 16 + WEAK_UNDEF:
    case WEAK_COMMON * 16 + WEAK_UNDEF:
    case DYN_COMMON * 16 + WEAK_UNDEF:
    case DYN_WEAK_COMMON * 16 + WEAK_UNDEF:
      // A new weak undefined reference tells us nothing.
      return;

    case DEF * 16 + DYN_UNDEF:
    case WEAK_DEF * 16 + DYN_UNDEF:
    case DYN_DEF * 16 + DYN_UNDEF:
    case DYN_WEAK_DEF * 16 + DYN_UNDEF:
    case UNDEF * 16 + DYN_UNDEF:
    case WEAK_UNDEF * 16 + DYN_UNDEF:
    case DYN_UNDEF * 16 + DYN_UNDEF:
    case DYN_WEAK_UNDEF * 16 + DYN_UNDEF:
    case COMMON * 16 + DYN_UNDEF:
    case WEAK_COMMON * 16 + DYN_UNDEF:
    case DYN_COMMON * 16 + DYN_UNDEF:
    case DYN_WEAK_COMMON * 16 + DYN_UNDEF:
      // A new dynamic undefined reference tells us nothing.
      return;

    case DEF * 16 + DYN_WEAK_UNDEF:
    case WEAK_DEF * 16 + DYN_WEAK_UNDEF:
    case DYN_DEF * 16 + DYN_WEAK_UNDEF:
    case DYN_WEAK_DEF * 16 + DYN_WEAK_UNDEF:
    case UNDEF * 16 + DYN_WEAK_UNDEF:
    case WEAK_UNDEF * 16 + DYN_WEAK_UNDEF:
    case DYN_UNDEF * 16 + DYN_WEAK_UNDEF:
    case DYN_WEAK_UNDEF * 16 + DYN_WEAK_UNDEF:
    case COMMON * 16 + DYN_WEAK_UNDEF:
    case WEAK_COMMON * 16 + DYN_WEAK_UNDEF:
    case DYN_COMMON * 16 + DYN_WEAK_UNDEF:
    case DYN_WEAK_COMMON * 16 + DYN_WEAK_UNDEF:
      // A new weak dynamic undefined reference tells us nothing.
      return;

    case DEF * 16 + COMMON:
      // A common symbol does not override a definition.
      return;

    case WEAK_DEF * 16 + COMMON:
    case DYN_DEF * 16 + COMMON:
    case DYN_WEAK_DEF * 16 + COMMON:
      // A common symbol does override a weak definition or a dynamic
      // definition.
      to->override(sym, object);
      return;

    case UNDEF * 16 + COMMON:
    case WEAK_UNDEF * 16 + COMMON:
    case DYN_UNDEF * 16 + COMMON:
    case DYN_WEAK_UNDEF * 16 + COMMON:
      // A common symbol is a definition for a reference.
      to->override(sym, object);
      return;

    case COMMON * 16 + COMMON:
    case WEAK_COMMON * 16 + COMMON:
    case DYN_COMMON * 16 + COMMON:
    case DYN_WEAK_COMMON * 16 + COMMON:

    case DEF * 16 + WEAK_COMMON:
    case WEAK_DEF * 16 + WEAK_COMMON:
    case DYN_DEF * 16 + WEAK_COMMON:
    case DYN_WEAK_DEF * 16 + WEAK_COMMON:
    case UNDEF * 16 + WEAK_COMMON:
    case WEAK_UNDEF * 16 + WEAK_COMMON:
    case DYN_UNDEF * 16 + WEAK_COMMON:
    case DYN_WEAK_UNDEF * 16 + WEAK_COMMON:
    case COMMON * 16 + WEAK_COMMON:
    case WEAK_COMMON * 16 + WEAK_COMMON:
    case DYN_COMMON * 16 + WEAK_COMMON:
    case DYN_WEAK_COMMON * 16 + WEAK_COMMON:

    case DEF * 16 + DYN_COMMON:
    case WEAK_DEF * 16 + DYN_COMMON:
    case DYN_DEF * 16 + DYN_COMMON:
    case DYN_WEAK_DEF * 16 + DYN_COMMON:
    case UNDEF * 16 + DYN_COMMON:
    case WEAK_UNDEF * 16 + DYN_COMMON:
    case DYN_UNDEF * 16 + DYN_COMMON:
    case DYN_WEAK_UNDEF * 16 + DYN_COMMON:
    case COMMON * 16 + DYN_COMMON:
    case WEAK_COMMON * 16 + DYN_COMMON:
    case DYN_COMMON * 16 + DYN_COMMON:
    case DYN_WEAK_COMMON * 16 + DYN_COMMON:

    case DEF * 16 + DYN_WEAK_COMMON:
    case WEAK_DEF * 16 + DYN_WEAK_COMMON:
    case DYN_DEF * 16 + DYN_WEAK_COMMON:
    case DYN_WEAK_DEF * 16 + DYN_WEAK_COMMON:
    case UNDEF * 16 + DYN_WEAK_COMMON:
    case WEAK_UNDEF * 16 + DYN_WEAK_COMMON:
    case DYN_UNDEF * 16 + DYN_WEAK_COMMON:
    case DYN_WEAK_UNDEF * 16 + DYN_WEAK_COMMON:
    case COMMON * 16 + DYN_WEAK_COMMON:
    case WEAK_COMMON * 16 + DYN_WEAK_COMMON:
    case DYN_COMMON * 16 + DYN_WEAK_COMMON:
    case DYN_WEAK_COMMON * 16 + DYN_WEAK_COMMON:
      abort();
      break;

    default:
      abort();
    }
}

// Instantiate the templates we need.  We could use the configure
// script to restrict this to only the ones needed for implemented
// targets.

template
void
Symbol_table::resolve<32, true>(
    Sized_symbol<32>* to,
    const elfcpp::Sym<32, true>& sym,
    Object* object);

template
void
Symbol_table::resolve<32, false>(
    Sized_symbol<32>* to,
    const elfcpp::Sym<32, false>& sym,
    Object* object);

template
void
Symbol_table::resolve<64, true>(
    Sized_symbol<64>* to,
    const elfcpp::Sym<64, true>& sym,
    Object* object);

template
void
Symbol_table::resolve<64, false>(
    Sized_symbol<64>* to,
    const elfcpp::Sym<64, false>& sym,
    Object* object);

} // End namespace gold.
Commit	Line	Data
14bfc3f5 ILT	1	// resolve.cc -- symbol resolution for gold
	2
	3	#include "gold.h"
	4
	5	#include "elfcpp.h"
	6	#include "target.h"
	7	#include "object.h"
	8	#include "symtab.h"
	9
	10	namespace gold
	11	{
	12
1564db8d ILT	13	// Symbol methods used in this file.
	14
	15	// Override the fields in Symbol.
	16
	17	template<int size, bool big_endian>
	18	void
	19	Symbol::override_base(const elfcpp::Sym<size, big_endian>& sym,
	20	Object* object)
	21	{
	22	this->object_ = object;
	23	this->shnum_ = sym.get_st_shndx(); // FIXME: Handle SHN_XINDEX.
	24	this->type_ = sym.get_st_type();
	25	this->binding_ = sym.get_st_bind();
	26	this->visibility_ = sym.get_st_visibility();
	27	this->other_ = sym.get_st_nonvis();
	28	}
	29
	30	// Override the fields in Sized_symbol.
	31
	32	template<int size>
	33	template<bool big_endian>
	34	void
	35	Sized_symbol<size>::override(const elfcpp::Sym<size, big_endian>& sym,
	36	Object* object)
	37	{
	38	this->override_base(sym, object);
	39	this->value_ = sym.get_st_value();
	40	this->size_ = sym.get_st_size();
	41	}
	42
14bfc3f5 ILT	43	// Resolve a symbol. This is called the second and subsequent times
	44	// we see a symbol. TO is the pre-existing symbol. SYM is the new
	45	// symbol, seen in OBJECT.
	46
	47	template<int size, bool big_endian>
	48	void
1564db8d	49	Symbol_table::resolve(Sized_symbol<size>* to,
14bfc3f5 ILT	50	const elfcpp::Sym<size, big_endian>& sym,
	51	Object* object)
	52	{
	53	if (object->target()->has_resolve())
	54	{
	55	object->sized_target<size, big_endian>()->resolve(to, sym, object);
	56	return;
	57	}
	58
	59	// Build a little code for each symbol.
	60	// Bit 0: 0 for global, 1 for weak.
	61	// Bit 1: 0 for regular object, 1 for shared object
	62	// Bits 2-3: 0 for normal, 1 for undefined, 2 for common
	63	// This gives us values from 0 to 11:
	64
	65	enum
	66	{
	67	DEF = 0,
	68	WEAK_DEF = 1,
	69	DYN_DEF = 2,
	70	DYN_WEAK_DEF = 3,
	71	UNDEF = 4,
	72	WEAK_UNDEF = 5,
	73	DYN_UNDEF = 6,
	74	DYN_WEAK_UNDEF = 7,
	75	COMMON = 8,
	76	WEAK_COMMON = 9,
	77	DYN_COMMON = 10,
	78	DYN_WEAK_COMMON = 11
	79	};
	80
	81	int tobits;
	82	switch (to->binding())
	83	{
	84	case elfcpp::STB_GLOBAL:
	85	tobits = 0;
	86	break;
	87
	88	case elfcpp::STB_WEAK:
	89	tobits = 1;
	90	break;
	91
	92	case elfcpp::STB_LOCAL:
	93	// We should only see externally visible symbols in the symbol
	94	// table.
	95	abort();
	96
	97	default:
	98	// Any target which wants to handle STB_LOOS, etc., needs to
	99	// define a resolve method.
	100	abort();
	101	}
	102
	103	if (to->object() != NULL && to->object()->is_dynamic())
	104	tobits \|= (1 << 1);
	105
	106	switch (to->shnum())
	107	{
	108	case elfcpp::SHN_UNDEF:
	109	tobits \|= (1 << 2);
	110	break;
	111
	112	case elfcpp::SHN_COMMON:
	113	tobits \|= (2 << 2);
114	break;
115
116	default:
1564db8d ILT	117	if (to->type() == elfcpp::STT_COMMON)
1564db8d ILT	118	tobits \|= (2 << 2);
14bfc3f5 ILT	119	break;
	120	}
	121
	122	int frombits;
	123	switch (sym.get_st_bind())
	124	{
	125	case elfcpp::STB_GLOBAL:
	126	frombits = 0;
	127	break;
	128
	129	case elfcpp::STB_WEAK:
	130	frombits = 1;
	131	break;
	132
	133	case elfcpp::STB_LOCAL:
	134	fprintf(stderr,
	135	_("%s: %s: invalid STB_LOCAL symbol %s in external symbols\n"),
	136	program_name, object->name().c_str(), to->name());
	137	gold_exit(false);
	138
	139	default:
	140	fprintf(stderr,
	141	_("%s: %s: unsupported symbol binding %d for symbol %s\n"),
	142	program_name, object->name().c_str(),
	143	static_cast<int>(sym.get_st_bind()), to->name());
	144	gold_exit(false);
	145	}
	146
	147	if (object->is_dynamic())
1564db8d ILT	148	{
	149	frombits \|= (1 << 1);
	150
	151	// Record that we've seen this symbol in a dynamic object.
	152	to->set_in_dyn();
	153	}
14bfc3f5 ILT	154
	155	switch (sym.get_st_shndx())
	156	{
	157	case elfcpp::SHN_UNDEF:
	158	frombits \|= (1 << 2);
	159	break;
	160
	161	case elfcpp::SHN_COMMON:
	162	frombits \|= (2 << 2);
	163	break;
	164
	165	default:
1564db8d ILT	166	if (sym.get_st_type() == elfcpp::STT_COMMON)
1564db8d ILT	167	frombits \|= (2 << 2);
14bfc3f5 ILT	168	break;
	169	}
	170
1564db8d ILT	171	// FIXME: Warn if either but not both of TO and SYM are STT_TLS.
1564db8d ILT	172
14bfc3f5 ILT	173	// We use a giant switch table for symbol resolution. This code is
	174	// unwieldy, but: 1) it is efficient; 2) we definitely handle all
	175	// cases; 3) it is easy to change the handling of a particular case.
	176	// The alternative would be a series of conditionals, but it is easy
	177	// to get the ordering wrong. This could also be done as a table,
	178	// but that is no easier to understand than this large switch
	179	// statement.
	180
	181	switch (tobits * 16 + frombits)
	182	{
	183	case DEF * 16 + DEF:
	184	// Two definitions of the same symbol.
	185	fprintf(stderr, "%s: %s: multiple definition of %s\n",
	186	program_name, object->name().c_str(), to->name());
	187	// FIXME: Report locations. Record that we have seen an error.
	188	return;
	189
	190	case WEAK_DEF * 16 + DEF:
1564db8d ILT	191	// We've seen a weak definition, and now we see a strong
	192	// definition. In the original SVR4 linker, this was treated as
	193	// a multiple definition error. In the Solaris linker and the
	194	// GNU linker, a weak definition followed by a regular
	195	// definition causes the weak definition to be overridden. We
	196	// are currently compatible with the GNU linker. In the future
	197	// we should add a target specific option to change this.
	198	// FIXME.
	199	to->override(sym, object);
14bfc3f5 ILT	200	return;
	201
	202	case DYN_DEF * 16 + DEF:
	203	case DYN_WEAK_DEF * 16 + DEF:
1564db8d ILT	204	// We've seen a definition in a dynamic object, and now we see a
	205	// definition in a regular object. The definition in the
	206	// regular object overrides the definition in the dynamic
	207	// object.
	208	to->override(sym, object);
	209	return;
	210
14bfc3f5 ILT	211	case UNDEF * 16 + DEF:
	212	case WEAK_UNDEF * 16 + DEF:
	213	case DYN_UNDEF * 16 + DEF:
	214	case DYN_WEAK_UNDEF * 16 + DEF:
1564db8d ILT	215	// We've seen an undefined reference, and now we see a
	216	// definition. We use the definition.
	217	to->override(sym, object);
	218	return;
	219
14bfc3f5 ILT	220	case COMMON * 16 + DEF:
	221	case WEAK_COMMON * 16 + DEF:
	222	case DYN_COMMON * 16 + DEF:
	223	case DYN_WEAK_COMMON * 16 + DEF:
1564db8d ILT	224	// We've seen a common symbol and now we see a definition. The
	225	// definition overrides. FIXME: We should optionally issue a
	226	// warning.
	227	to->override(sym, object);
	228	return;
14bfc3f5 ILT	229
	230	case DEF * 16 + WEAK_DEF:
	231	case WEAK_DEF * 16 + WEAK_DEF:
1564db8d ILT	232	// We've seen a definition and now we see a weak definition. We
	233	// ignore the new weak definition.
	234	return;
	235
14bfc3f5 ILT	236	case DYN_DEF * 16 + WEAK_DEF:
14bfc3f5 ILT	237	case DYN_WEAK_DEF * 16 + WEAK_DEF:
1564db8d ILT	238	// We've seen a dynamic definition and now we see a regular weak
	239	// definition. The regular weak definition overrides.
	240	to->override(sym, object);
	241	return;
	242
14bfc3f5 ILT	243	case UNDEF * 16 + WEAK_DEF:
	244	case WEAK_UNDEF * 16 + WEAK_DEF:
	245	case DYN_UNDEF * 16 + WEAK_DEF:
	246	case DYN_WEAK_UNDEF * 16 + WEAK_DEF:
1564db8d ILT	247	// A weak definition of a currently undefined symbol.
	248	to->override(sym, object);
	249	return;
	250
14bfc3f5 ILT	251	case COMMON * 16 + WEAK_DEF:
14bfc3f5 ILT	252	case WEAK_COMMON * 16 + WEAK_DEF:
1564db8d ILT	253	// A weak definition does not override a common definition.
	254	return;
	255
14bfc3f5 ILT	256	case DYN_COMMON * 16 + WEAK_DEF:
14bfc3f5 ILT	257	case DYN_WEAK_COMMON * 16 + WEAK_DEF:
1564db8d ILT	258	// A weak definition does override a definition in a dynamic
	259	// object. FIXME: We should optionally issue a warning.
	260	to->override(sym, object);
	261	return;
14bfc3f5 ILT	262
	263	case DEF * 16 + DYN_DEF:
	264	case WEAK_DEF * 16 + DYN_DEF:
	265	case DYN_DEF * 16 + DYN_DEF:
	266	case DYN_WEAK_DEF * 16 + DYN_DEF:
1564db8d ILT	267	// Ignore a dynamic definition if we already have a definition.
	268	return;
	269
14bfc3f5 ILT	270	case UNDEF * 16 + DYN_DEF:
	271	case WEAK_UNDEF * 16 + DYN_DEF:
	272	case DYN_UNDEF * 16 + DYN_DEF:
	273	case DYN_WEAK_UNDEF * 16 + DYN_DEF:
1564db8d ILT	274	// Use a dynamic definition if we have a reference.
	275	to->override(sym, object);
	276	return;
	277
14bfc3f5 ILT	278	case COMMON * 16 + DYN_DEF:
	279	case WEAK_COMMON * 16 + DYN_DEF:
	280	case DYN_COMMON * 16 + DYN_DEF:
	281	case DYN_WEAK_COMMON * 16 + DYN_DEF:
1564db8d ILT	282	// Ignore a dynamic definition if we already have a common
	283	// definition.
	284	return;
14bfc3f5 ILT	285
	286	case DEF * 16 + DYN_WEAK_DEF:
	287	case WEAK_DEF * 16 + DYN_WEAK_DEF:
	288	case DYN_DEF * 16 + DYN_WEAK_DEF:
	289	case DYN_WEAK_DEF * 16 + DYN_WEAK_DEF:
1564db8d ILT	290	// Ignore a weak dynamic definition if we already have a
	291	// definition.
	292	return;
	293
14bfc3f5 ILT	294	case UNDEF * 16 + DYN_WEAK_DEF:
	295	case WEAK_UNDEF * 16 + DYN_WEAK_DEF:
	296	case DYN_UNDEF * 16 + DYN_WEAK_DEF:
	297	case DYN_WEAK_UNDEF * 16 + DYN_WEAK_DEF:
1564db8d ILT	298	// Use a weak dynamic definition if we have a reference.
	299	to->override(sym, object);
	300	return;
	301
14bfc3f5 ILT	302	case COMMON * 16 + DYN_WEAK_DEF:
	303	case WEAK_COMMON * 16 + DYN_WEAK_DEF:
	304	case DYN_COMMON * 16 + DYN_WEAK_DEF:
	305	case DYN_WEAK_COMMON * 16 + DYN_WEAK_DEF:
1564db8d ILT	306	// Ignore a weak dynamic definition if we already have a common
	307	// definition.
	308	return;
14bfc3f5 ILT	309
	310	case DEF * 16 + UNDEF:
	311	case WEAK_DEF * 16 + UNDEF:
	312	case DYN_DEF * 16 + UNDEF:
	313	case DYN_WEAK_DEF * 16 + UNDEF:
	314	case UNDEF * 16 + UNDEF:
	315	case WEAK_UNDEF * 16 + UNDEF:
	316	case DYN_UNDEF * 16 + UNDEF:
	317	case DYN_WEAK_UNDEF * 16 + UNDEF:
	318	case COMMON * 16 + UNDEF:
	319	case WEAK_COMMON * 16 + UNDEF:
	320	case DYN_COMMON * 16 + UNDEF:
	321	case DYN_WEAK_COMMON * 16 + UNDEF:
1564db8d ILT	322	// A new undefined reference tells us nothing.
1564db8d ILT	323	return;
14bfc3f5 ILT	324
	325	case DEF * 16 + WEAK_UNDEF:
	326	case WEAK_DEF * 16 + WEAK_UNDEF:
	327	case DYN_DEF * 16 + WEAK_UNDEF:
	328	case DYN_WEAK_DEF * 16 + WEAK_UNDEF:
	329	case UNDEF * 16 + WEAK_UNDEF:
	330	case WEAK_UNDEF * 16 + WEAK_UNDEF:
	331	case DYN_UNDEF * 16 + WEAK_UNDEF:
	332	case DYN_WEAK_UNDEF * 16 + WEAK_UNDEF:
	333	case COMMON * 16 + WEAK_UNDEF:
	334	case WEAK_COMMON * 16 + WEAK_UNDEF:
	335	case DYN_COMMON * 16 + WEAK_UNDEF:
	336	case DYN_WEAK_COMMON * 16 + WEAK_UNDEF:
1564db8d ILT	337	// A new weak undefined reference tells us nothing.
1564db8d ILT	338	return;
14bfc3f5 ILT	339
	340	case DEF * 16 + DYN_UNDEF:
	341	case WEAK_DEF * 16 + DYN_UNDEF:
	342	case DYN_DEF * 16 + DYN_UNDEF:
	343	case DYN_WEAK_DEF * 16 + DYN_UNDEF:
	344	case UNDEF * 16 + DYN_UNDEF:
	345	case WEAK_UNDEF * 16 + DYN_UNDEF:
	346	case DYN_UNDEF * 16 + DYN_UNDEF:
	347	case DYN_WEAK_UNDEF * 16 + DYN_UNDEF:
	348	case COMMON * 16 + DYN_UNDEF:
	349	case WEAK_COMMON * 16 + DYN_UNDEF:
	350	case DYN_COMMON * 16 + DYN_UNDEF:
	351	case DYN_WEAK_COMMON * 16 + DYN_UNDEF:
1564db8d ILT	352	// A new dynamic undefined reference tells us nothing.
1564db8d ILT	353	return;
14bfc3f5 ILT	354
	355	case DEF * 16 + DYN_WEAK_UNDEF:
	356	case WEAK_DEF * 16 + DYN_WEAK_UNDEF:
	357	case DYN_DEF * 16 + DYN_WEAK_UNDEF:
	358	case DYN_WEAK_DEF * 16 + DYN_WEAK_UNDEF:
	359	case UNDEF * 16 + DYN_WEAK_UNDEF:
	360	case WEAK_UNDEF * 16 + DYN_WEAK_UNDEF:
	361	case DYN_UNDEF * 16 + DYN_WEAK_UNDEF:
	362	case DYN_WEAK_UNDEF * 16 + DYN_WEAK_UNDEF:
	363	case COMMON * 16 + DYN_WEAK_UNDEF:
	364	case WEAK_COMMON * 16 + DYN_WEAK_UNDEF:
	365	case DYN_COMMON * 16 + DYN_WEAK_UNDEF:
	366	case DYN_WEAK_COMMON * 16 + DYN_WEAK_UNDEF:
1564db8d ILT	367	// A new weak dynamic undefined reference tells us nothing.
1564db8d ILT	368	return;
14bfc3f5 ILT	369
14bfc3f5 ILT	370	case DEF * 16 + COMMON:
1564db8d ILT	371	// A common symbol does not override a definition.
	372	return;
	373
14bfc3f5 ILT	374	case WEAK_DEF * 16 + COMMON:
	375	case DYN_DEF * 16 + COMMON:
	376	case DYN_WEAK_DEF * 16 + COMMON:
1564db8d ILT	377	// A common symbol does override a weak definition or a dynamic
	378	// definition.
	379	to->override(sym, object);
	380	return;
	381
14bfc3f5 ILT	382	case UNDEF * 16 + COMMON:
	383	case WEAK_UNDEF * 16 + COMMON:
	384	case DYN_UNDEF * 16 + COMMON:
	385	case DYN_WEAK_UNDEF * 16 + COMMON:
1564db8d ILT	386	// A common symbol is a definition for a reference.
	387	to->override(sym, object);
	388	return;
	389
14bfc3f5 ILT	390	case COMMON * 16 + COMMON:
	391	case WEAK_COMMON * 16 + COMMON:
	392	case DYN_COMMON * 16 + COMMON:
	393	case DYN_WEAK_COMMON * 16 + COMMON:
	394
	395	case DEF * 16 + WEAK_COMMON:
	396	case WEAK_DEF * 16 + WEAK_COMMON:
	397	case DYN_DEF * 16 + WEAK_COMMON:
	398	case DYN_WEAK_DEF * 16 + WEAK_COMMON:
	399	case UNDEF * 16 + WEAK_COMMON:
	400	case WEAK_UNDEF * 16 + WEAK_COMMON:
	401	case DYN_UNDEF * 16 + WEAK_COMMON:
	402	case DYN_WEAK_UNDEF * 16 + WEAK_COMMON:
	403	case COMMON * 16 + WEAK_COMMON:
	404	case WEAK_COMMON * 16 + WEAK_COMMON:
	405	case DYN_COMMON * 16 + WEAK_COMMON:
	406	case DYN_WEAK_COMMON * 16 + WEAK_COMMON:
	407
	408	case DEF * 16 + DYN_COMMON:
	409	case WEAK_DEF * 16 + DYN_COMMON:
	410	case DYN_DEF * 16 + DYN_COMMON:
	411	case DYN_WEAK_DEF * 16 + DYN_COMMON:
	412	case UNDEF * 16 + DYN_COMMON:
	413	case WEAK_UNDEF * 16 + DYN_COMMON:
	414	case DYN_UNDEF * 16 + DYN_COMMON:
	415	case DYN_WEAK_UNDEF * 16 + DYN_COMMON:
	416	case COMMON * 16 + DYN_COMMON:
	417	case WEAK_COMMON * 16 + DYN_COMMON:
	418	case DYN_COMMON * 16 + DYN_COMMON:
	419	case DYN_WEAK_COMMON * 16 + DYN_COMMON:
	420
	421	case DEF * 16 + DYN_WEAK_COMMON:
	422	case WEAK_DEF * 16 + DYN_WEAK_COMMON:
	423	case DYN_DEF * 16 + DYN_WEAK_COMMON:
	424	case DYN_WEAK_DEF * 16 + DYN_WEAK_COMMON:
	425	case UNDEF * 16 + DYN_WEAK_COMMON:
	426	case WEAK_UNDEF * 16 + DYN_WEAK_COMMON:
	427	case DYN_UNDEF * 16 + DYN_WEAK_COMMON:
	428	case DYN_WEAK_UNDEF * 16 + DYN_WEAK_COMMON:
	429	case COMMON * 16 + DYN_WEAK_COMMON:
	430	case WEAK_COMMON * 16 + DYN_WEAK_COMMON:
	431	case DYN_COMMON * 16 + DYN_WEAK_COMMON:
	432	case DYN_WEAK_COMMON * 16 + DYN_WEAK_COMMON:
1564db8d	433	abort();
14bfc3f5	434	break;
1564db8d ILT	435
	436	default:
	437	abort();
14bfc3f5 ILT	438	}
	439	}
	440
	441	// Instantiate the templates we need. We could use the configure
	442	// script to restrict this to only the ones needed for implemented
	443	// targets.
	444
	445	template
	446	void
	447	Symbol_table::resolve<32, true>(
1564db8d	448	Sized_symbol<32>* to,
14bfc3f5 ILT	449	const elfcpp::Sym<32, true>& sym,
	450	Object* object);
	451
	452	template
	453	void
	454	Symbol_table::resolve<32, false>(
1564db8d	455	Sized_symbol<32>* to,
14bfc3f5 ILT	456	const elfcpp::Sym<32, false>& sym,
	457	Object* object);
	458
	459	template
	460	void
	461	Symbol_table::resolve<64, true>(
1564db8d	462	Sized_symbol<64>* to,
14bfc3f5 ILT	463	const elfcpp::Sym<64, true>& sym,
	464	Object* object);
	465
	466	template
	467	void
	468	Symbol_table::resolve<64, false>(
1564db8d	469	Sized_symbol<64>* to,
14bfc3f5 ILT	470	const elfcpp::Sym<64, false>& sym,
	471	Object* object);
	472
	473	} // End namespace gold.