darlinghq/darling-gdb
1
0
Fork 0
mirror of https://github.com/darlinghq/darling-gdb.git synced 2025-02-12 20:58:48 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity
darling-gdb/gold/resolve.cc
Ian Lance Taylor 14bfc3f555 Another snapshot of the current state of the sources. Gets to the 
point of symbol resolution and can now issue a multiple definition
error.  Also added target selection infrastructure.
2006-08-18 22:29:20 +00:00

350 lines
9.7 KiB
C++
Raw Blame History

// resolve.cc -- symbol resolution for gold
#include "gold.h"
#include "elfcpp.h"
#include "target.h"
#include "object.h"
#include "symtab.h"
namespace gold
{
// 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(Symbol* 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:
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);
switch (sym.get_st_shndx())
{
case elfcpp::SHN_UNDEF:
frombits |= (1 << 2);
break;
case elfcpp::SHN_COMMON:
frombits |= (2 << 2);
break;
default:
break;
}
// 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:
// In the original SVR4 linker, a weak definition followed by a
// regular definition 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
// regular definition to be ignored. We are currently
// compatible with the GNU linker. In the future we should add
// a target specific option to change this. FIXME.
return;
case DYN_DEF * 16 + DEF:
case DYN_WEAK_DEF * 16 + DEF:
case UNDEF * 16 + DEF:
case WEAK_UNDEF * 16 + DEF:
case DYN_UNDEF * 16 + DEF:
case DYN_WEAK_UNDEF * 16 + DEF:
case COMMON * 16 + DEF:
case WEAK_COMMON * 16 + DEF:
case DYN_COMMON * 16 + DEF:
case DYN_WEAK_COMMON * 16 + DEF:
case DEF * 16 + WEAK_DEF:
case WEAK_DEF * 16 + WEAK_DEF:
case DYN_DEF * 16 + WEAK_DEF:
case DYN_WEAK_DEF * 16 + WEAK_DEF:
case UNDEF * 16 + WEAK_DEF:
case WEAK_UNDEF * 16 + WEAK_DEF:
case DYN_UNDEF * 16 + WEAK_DEF:
case DYN_WEAK_UNDEF * 16 + WEAK_DEF:
case COMMON * 16 + WEAK_DEF:
case WEAK_COMMON * 16 + WEAK_DEF:
case DYN_COMMON * 16 + WEAK_DEF:
case DYN_WEAK_COMMON * 16 + WEAK_DEF:
case DEF * 16 + DYN_DEF:
case WEAK_DEF * 16 + DYN_DEF:
case DYN_DEF * 16 + DYN_DEF:
case DYN_WEAK_DEF * 16 + DYN_DEF:
case UNDEF * 16 + DYN_DEF:
case WEAK_UNDEF * 16 + DYN_DEF:
case DYN_UNDEF * 16 + DYN_DEF:
case DYN_WEAK_UNDEF * 16 + DYN_DEF:
case COMMON * 16 + DYN_DEF:
case WEAK_COMMON * 16 + DYN_DEF:
case DYN_COMMON * 16 + DYN_DEF:
case DYN_WEAK_COMMON * 16 + DYN_DEF:
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:
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:
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:
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:
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:
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:
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:
case DEF * 16 + COMMON:
case WEAK_DEF * 16 + COMMON:
case DYN_DEF * 16 + COMMON:
case DYN_WEAK_DEF * 16 + COMMON:
case UNDEF * 16 + COMMON:
case WEAK_UNDEF * 16 + COMMON:
case DYN_UNDEF * 16 + COMMON:
case DYN_WEAK_UNDEF * 16 + COMMON:
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:
break;
}
}
// 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>(
Symbol* to,
const elfcpp::Sym<32, true>& sym,
Object* object);
template
void
Symbol_table::resolve<32, false>(
Symbol* to,
const elfcpp::Sym<32, false>& sym,
Object* object);
template
void
Symbol_table::resolve<64, true>(
Symbol* to,
const elfcpp::Sym<64, true>& sym,
Object* object);
template
void
Symbol_table::resolve<64, false>(
Symbol* to,
const elfcpp::Sym<64, false>& sym,
Object* object);
} // End namespace gold.
Reference in New Issue View Git Blame Copy Permalink