GAS is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
GAS is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GAS; see the file COPYING. If not, write to the Free
Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
02110-1301, USA. */
/* #define DEBUG_SYMS / * to debug symbol list maintenance. */
struct symbol_flags
{
/* Whether the symbol is a local_symbol. */
unsigned int local_symbol : 1;
/* Weather symbol has been written. */
unsigned int written : 1;
/* Whether symbol value has been completely resolved (used during
final pass over symbol table). */
unsigned int resolved : 1;
/* Whether the symbol value is currently being resolved (used to
detect loops in symbol dependencies). */
unsigned int resolving : 1;
/* Whether the symbol value is used in a reloc. This is used to
ensure that symbols used in relocs are written out, even if they
are local and would otherwise not be. */
unsigned int used_in_reloc : 1;
/* Whether the symbol is used as an operand or in an expression.
NOTE: Not all the backends keep this information accurate;
backends which use this bit are responsible for setting it when
a symbol is used in backend routines. */
unsigned int used : 1;
/* Whether the symbol can be re-defined. */
unsigned int volatil : 1;
/* Whether the symbol is a forward reference, and whether such has
been determined. */
unsigned int forward_ref : 1;
unsigned int forward_resolved : 1;
/* This is set if the symbol is defined in an MRI common section.
We handle such sections as single common symbols, so symbols
defined within them must be treated specially by the relocation
routines. */
unsigned int mri_common : 1;
/* This is set if the symbol is set with a .weakref directive. */
unsigned int weakrefr : 1;
/* This is set when the symbol is referenced as part of a .weakref
directive, but only if the symbol was not in the symbol table
before. It is cleared as soon as any direct reference to the
symbol is present. */
unsigned int weakrefd : 1;
/* Whether the symbol has been marked to be removed by a .symver
directive. */
unsigned int removed : 1;
/* Set when a warning about the symbol containing multibyte characters
is generated. */
unsigned int multibyte_warned : 1;
};
/* A pointer in the symbol may point to either a complete symbol
(struct symbol below) or to a local symbol (struct local_symbol
defined here). The symbol code can detect the case by examining
the first field which is present in both structs.
We do this because we ordinarily only need a small amount of
information for a local symbol. The symbol table takes up a lot of
space, and storing less information for a local symbol can make a
big difference in assembler memory usage when assembling a large
file. */
struct local_symbol
{
/* Symbol flags. Only local_symbol and resolved are relevant. */
struct symbol_flags flags;
/* Hash value calculated from name. */
hashval_t hash;
/* The symbol name. */
const char *name;
/* The symbol frag. */
fragS *frag;
/* The symbol section. */
asection *section;
/* The value of the symbol. */
valueT value;
};
/* The information we keep for a symbol. The symbol table holds
pointers both to this and to local_symbol structures. The first
three fields must be identical to struct local_symbol, and the size
should be the same as or smaller than struct local_symbol.
Fields that don't fit go to an extension structure. */
struct symbol
{
/* Symbol flags. */
struct symbol_flags flags;
/* Hash value calculated from name. */
hashval_t hash;
/* The symbol name. */
const char *name;
/* Pointer to the frag this symbol is attached to, if any.
Otherwise, NULL. */
fragS *frag;
/* BFD symbol */
asymbol *bsym;
/* Extra symbol fields that won't fit. */
struct xsymbol *x;
};
/* Extra fields to make up a full symbol. */
struct xsymbol
{
/* The value of the symbol. */
expressionS value;
/* Forwards and backwards chain pointers. */
struct symbol *next;
struct symbol *previous;
/* Utility functions to allocate and duplicate memory on the notes
obstack, each like the corresponding function without "notes_"
prefix. All of these exit on an allocation failure. */
#ifdef TE_PE
/* The name of an external symbol which is
used to make weak PE symbol names unique. */
const char * an_external_name;
#endif
/* Return a pointer to a new symbol. Die if we can't make a new
symbol. Fill in the symbol's values. Add symbol to end of symbol
chain.
This function should be called in the general case of creating a
symbol. However, if the output file symbol table has already been
set, and you are certain that this symbol won't be wanted in the
output file, you can call symbol_create. */
/* symbol must be born in some fixed state. This seems as good as any. */
memset (symbolP, 0, size);
symbolP->name = preserved_copy_of_name;
symbolP->x = (struct xsymbol *) (symbolP + 1);
/* We have just seen "<name>:".
Creates a struct symbol unless it already exists.
Gripes if we are redefining a symbol incompatibly (and ignores it). */
symbolS *
colon (/* Just seen "x:" - rattle symbols & frags. */
const char *sym_name /* Symbol name, as a canonical string. */
/* We copy this string: OK to alter later. */)
{
symbolS *symbolP; /* Symbol we are working with. */
/* Sun local labels go out of scope whenever a non-local symbol is
defined. */
if (LOCAL_LABELS_DOLLAR
&& !bfd_is_local_label_name (stdoutput, sym_name))
dollar_label_clear ();
#ifndef WORKING_DOT_WORD
if (new_broken_words)
{
struct broken_word *a;
int possible_bytes;
fragS *frag_tmp;
char *frag_opcode;
if (now_seg == absolute_section)
{
as_bad (_("cannot define symbol `%s' in absolute section"), sym_name);
return NULL;
}
/* We want to store the pointer to where to insert the jump
table in the fr_opcode of the rs_broken_word frag. This
requires a little hackery. */
while (frag_tmp
&& (frag_tmp->fr_type != rs_broken_word
|| frag_tmp->fr_opcode))
frag_tmp = frag_tmp->fr_next;
know (frag_tmp);
frag_tmp->fr_opcode = frag_opcode;
new_broken_words = 0;
for (a = broken_words; a && a->dispfrag == 0; a = a->next_broken_word)
a->dispfrag = frag_tmp;
}
#endif /* WORKING_DOT_WORD */
locsym->section = now_seg;
locsym->frag = frag_now;
locsym->value = frag_now_fix ();
}
else if (!(S_IS_DEFINED (symbolP) || symbol_equated_p (symbolP))
|| S_IS_COMMON (symbolP)
|| S_IS_VOLATILE (symbolP))
{
if (S_IS_VOLATILE (symbolP))
{
symbolP = symbol_clone (symbolP, 1);
S_SET_VALUE (symbolP, 0);
S_CLEAR_VOLATILE (symbolP);
}
if (S_GET_VALUE (symbolP) == 0)
{
define_sym_at_dot (symbolP);
#ifdef N_UNDF
know (N_UNDF == 0);
#endif /* if we have one, it better be zero. */
}
else
{
/* There are still several cases to check:
A .comm/.lcomm symbol being redefined as initialized
data is OK
A .comm/.lcomm symbol being redefined with a larger
size is also OK
This only used to be allowed on VMS gas, but Sun cc
on the sparc also depends on it. */
if (((!S_IS_DEBUG (symbolP)
&& (!S_IS_DEFINED (symbolP) || S_IS_COMMON (symbolP))
&& S_IS_EXTERNAL (symbolP))
|| S_GET_SEGMENT (symbolP) == bss_section)
&& (now_seg == data_section
|| now_seg == bss_section
|| now_seg == S_GET_SEGMENT (symbolP)))
{
/* Select which of the 2 cases this is. */
if (now_seg != data_section)
{
/* New .comm for prev .comm symbol.
If the new size is larger we just change its
value. If the new size is smaller, we ignore
this symbol. */
if (S_GET_VALUE (symbolP)
< ((unsigned) frag_now_fix ()))
{
S_SET_VALUE (symbolP, (valueT) frag_now_fix ());
}
}
else
{
/* It is a .comm/.lcomm being converted to initialized
data. */
define_sym_at_dot (symbolP);
}
}
else
{
#if (!defined (OBJ_AOUT) && !defined (OBJ_MAYBE_AOUT))
static const char *od_buf = "";
#else
char od_buf[100];
od_buf[0] = '\0';
if (OUTPUT_FLAVOR == bfd_target_aout_flavour)
sprintf (od_buf, "%d.%d.",
S_GET_OTHER (symbolP),
S_GET_DESC (symbolP));
#endif
as_bad (_("symbol `%s' is already defined as \"%s\"/%s%ld"),
sym_name,
segment_name (S_GET_SEGMENT (symbolP)),
od_buf,
(long) S_GET_VALUE (symbolP));
}
} /* if the undefined symbol has no value */
}
else
{
/* Don't blow up if the definition is the same. */
if (!(frag_now == symbolP->frag
&& S_GET_VALUE (symbolP) == frag_now_fix ()
&& S_GET_SEGMENT (symbolP) == now_seg))
{
as_bad (_("symbol `%s' is already defined"), sym_name);
symbolP = symbol_clone (symbolP, 0);
define_sym_at_dot (symbolP);
}
}
if (mri_common_symbol != NULL)
{
/* This symbol is actually being defined within an MRI common
section. This requires special handling. */
if (symbolP->flags.local_symbol)
symbolP = local_symbol_convert (symbolP);
symbolP->x->value.X_op = O_symbol;
symbolP->x->value.X_add_symbol = mri_common_symbol;
symbolP->x->value.X_add_number = S_GET_VALUE (mri_common_symbol);
symbolP->frag = &zero_address_frag;
S_SET_SEGMENT (symbolP, expr_section);
symbolP->flags.mri_common = 1;
}
/* Make sure we never clone the dot special symbol. */
gas_assert (orgsymP != &dot_symbol);
/* When cloning a local symbol it isn't absolutely necessary to
convert the original, but converting makes the code much
simpler to cover this unexpected case. As of 2020-08-21
symbol_clone won't be called on a local symbol. */
if (orgsymP->flags.local_symbol)
orgsymP = local_symbol_convert (orgsymP);
bsymorg = orgsymP->bsym;
if (replace)
{
if (symbol_rootP == orgsymP)
symbol_rootP = newsymP;
else if (orgsymP->x->previous)
{
orgsymP->x->previous->x->next = newsymP;
orgsymP->x->previous = NULL;
}
if (symbol_lastP == orgsymP)
symbol_lastP = newsymP;
else if (orgsymP->x->next)
orgsymP->x->next->x->previous = newsymP;
/* Symbols that won't be output can't be external. */
S_CLEAR_EXTERNAL (orgsymP);
orgsymP->x->previous = orgsymP->x->next = orgsymP;
debug_verify_symchain (symbol_rootP, symbol_lastP);
symbol_table_insert (newsymP);
}
else
{
/* Symbols that won't be output can't be external. */
S_CLEAR_EXTERNAL (newsymP);
newsymP->x->previous = newsymP->x->next = newsymP;
}
return newsymP;
}
/* Referenced symbols, if they are forward references, need to be cloned
(without replacing the original) so that the value of the referenced
symbols at the point of use is saved by the clone. */
if (is_forward)
{
/* assign_symbol() clones volatile symbols; pre-existing expressions
hold references to the original instance, but want the current
value. Just repeat the lookup. */
if (add_symbol && S_IS_VOLATILE (add_symbol))
add_symbol = symbol_find_exact (S_GET_NAME (add_symbol));
if (op_symbol && S_IS_VOLATILE (op_symbol))
op_symbol = symbol_find_exact (S_GET_NAME (op_symbol));
}
/* Re-using resolving here, as this routine cannot get called from
symbol resolution code. */
if ((symbolP->bsym->section == expr_section
|| symbolP->flags.forward_ref)
&& !symbolP->flags.resolving)
{
symbolP->flags.resolving = 1;
add_symbol = symbol_clone_if_forward_ref (add_symbol, is_forward);
op_symbol = symbol_clone_if_forward_ref (op_symbol, is_forward);
symbolP->flags.resolving = 0;
}
/* Implement symbol table lookup.
In: A symbol's name as a string: '\0' can't be part of a symbol name.
Out: NULL if the name was not in the symbol table, else the address
of a struct symbol associated with that name. */
/* Any references to the symbol, except for the reference in
.weakref, must clear this flag, such that the symbol does not
turn into a weak symbol. Note that we don't have to handle the
local_symbol case, since a weakrefd is always promoted out of the
local_symbol table when it is turned into a weak symbol. */
if (sym && ! noref)
S_CLEAR_WEAKREFD (sym);
result = symbol_find_exact_noref (name, noref);
free (copy);
return result;
}
/* Once upon a time, symbols were kept in a singly linked list. At
least coff needs to be able to rearrange them from time to time, for
which a doubly linked list is much more convenient. Loic did these
as macros which seemed dangerous to me so they're now functions.
xoxorich. */
/* Link symbol ADDME after symbol TARGET in the chain. */
void
symbol_append (symbolS *addme, symbolS *target,
symbolS **rootPP, symbolS **lastPP)
{
extern int symbol_table_frozen;
if (symbol_table_frozen)
abort ();
if (addme->flags.local_symbol)
abort ();
if (target != NULL && target->flags.local_symbol)
abort ();
if (target == NULL)
{
know (*rootPP == NULL);
know (*lastPP == NULL);
addme->x->next = NULL;
addme->x->previous = NULL;
*rootPP = addme;
*lastPP = addme;
return;
} /* if the list is empty */
if (target->x->next != NULL)
{
target->x->next->x->previous = addme;
}
else
{
know (*lastPP == target);
*lastPP = addme;
} /* if we have a next */
int
symbol_on_chain (symbolS *s, symbolS *rootPP, symbolS *lastPP)
{
return (!s->flags.local_symbol
&& ((s->x->next != s
&& s->x->next != NULL
&& s->x->next->x->previous == s)
|| s == lastPP)
&& ((s->x->previous != s
&& s->x->previous != NULL
&& s->x->previous->x->next == s)
|| s == rootPP));
}
#ifdef OBJ_COMPLEX_RELC
static int
use_complex_relocs_for (symbolS * symp)
{
switch (symp->x->value.X_op)
{
case O_constant:
return 0;
case O_multiply:
case O_divide:
case O_modulus:
case O_left_shift:
case O_right_shift:
case O_bit_inclusive_or:
case O_bit_or_not:
case O_bit_exclusive_or:
case O_bit_and:
case O_add:
case O_subtract:
case O_eq:
case O_ne:
case O_lt:
case O_le:
case O_ge:
case O_gt:
case O_logical_and:
case O_logical_or:
if ((S_IS_COMMON (symp->x->value.X_op_symbol)
|| S_IS_LOCAL (symp->x->value.X_op_symbol))
&& S_IS_DEFINED (symp->x->value.X_op_symbol)
&& S_GET_SEGMENT (symp->x->value.X_op_symbol) != expr_section)
{
case O_symbol:
case O_symbol_rva:
case O_uminus:
case O_bit_not:
case O_logical_not:
if ((S_IS_COMMON (symp->x->value.X_add_symbol)
|| S_IS_LOCAL (symp->x->value.X_add_symbol))
&& S_IS_DEFINED (symp->x->value.X_add_symbol)
&& S_GET_SEGMENT (symp->x->value.X_add_symbol) != expr_section)
return 0;
}
break;
/* Help out with CSE. */
add_symbol = symp->x->value.X_add_symbol;
op_symbol = symp->x->value.X_op_symbol;
final_val = symp->x->value.X_add_number;
op = symp->x->value.X_op;
switch (op)
{
default:
BAD_CASE (op);
break;
case O_md1:
case O_md2:
case O_md3:
case O_md4:
case O_md5:
case O_md6:
case O_md7:
case O_md8:
case O_md9:
case O_md10:
case O_md11:
case O_md12:
case O_md13:
case O_md14:
case O_md15:
case O_md16:
case O_md17:
case O_md18:
case O_md19:
case O_md20:
case O_md21:
case O_md22:
case O_md23:
case O_md24:
case O_md25:
case O_md26:
case O_md27:
case O_md28:
case O_md29:
case O_md30:
case O_md31:
case O_md32:
#ifdef md_resolve_symbol
resolved = md_resolve_symbol (symp, &final_val, &final_seg);
if (resolved)
break;
#endif
goto exit_dont_set_value;
case O_absent:
final_val = 0;
/* Fall through. */
case O_constant:
/* Symbols whose section has SEC_ELF_OCTETS set,
resolve to octets instead of target bytes. */
if (symp->bsym->section->flags & SEC_OCTETS)
final_val += symp->frag->fr_address;
else
final_val += symp->frag->fr_address / OCTETS_PER_BYTE;
if (final_seg == expr_section)
final_seg = absolute_section;
/* Fall through. */
case O_register:
resolved = 1;
break;
case O_symbol:
case O_symbol_rva:
case O_secidx:
left = resolve_symbol_value (add_symbol);
seg_left = S_GET_SEGMENT (add_symbol);
if (finalize_syms)
symp->x->value.X_op_symbol = NULL;
if (symp->flags.mri_common)
{
/* This is a symbol inside an MRI common section. The
relocation routines are going to handle it specially.
Don't change the value. */
resolved = symbol_resolved_p (add_symbol);
break;
}
/* Don't leave symbol loops. */
if (finalize_syms
&& !add_symbol->flags.local_symbol
&& add_symbol->flags.resolving)
break;
if (finalize_syms && final_val == 0
#ifdef OBJ_XCOFF
/* Avoid changing symp's "within" when dealing with
AIX debug symbols. For some storage classes, "within"
have a special meaning.
C_DWARF should behave like on Linux, thus this check
isn't done to be closer. */
&& ((symbol_get_bfdsym (symp)->flags & BSF_DEBUGGING) == 0
|| (S_GET_STORAGE_CLASS (symp) == C_DWARF))
#endif
)
{
if (add_symbol->flags.local_symbol)
add_symbol = local_symbol_convert (add_symbol);
copy_symbol_attributes (symp, add_symbol);
}
/* If we have equated this symbol to an undefined or common
symbol, keep X_op set to O_symbol, and don't change
X_add_number. This permits the routine which writes out
relocation to detect this case, and convert the
relocation to be against the symbol to which this symbol
is equated. */
if (seg_left == undefined_section
|| bfd_is_com_section (seg_left)
#if defined (OBJ_COFF) && defined (TE_PE)
|| S_IS_WEAK (add_symbol)
#endif
|| (finalize_syms
&& ((final_seg == expr_section
&& seg_left != expr_section
&& seg_left != absolute_section)
|| symbol_shadow_p (symp))))
{
if (finalize_syms)
{
symp->x->value.X_op = O_symbol;
symp->x->value.X_add_symbol = add_symbol;
symp->x->value.X_add_number = final_val;
/* Use X_op_symbol as a flag. */
symp->x->value.X_op_symbol = add_symbol;
}
final_seg = seg_left;
final_val += symp->frag->fr_address + left;
resolved = symbol_resolved_p (add_symbol);
symp->flags.resolving = 0;
case O_uminus:
case O_bit_not:
case O_logical_not:
left = resolve_symbol_value (add_symbol);
seg_left = S_GET_SEGMENT (add_symbol);
/* By reducing these to the relevant dyadic operator, we get
!S -> S == 0 permitted on anything,
-S -> 0 - S only permitted on absolute
~S -> S ^ ~0 only permitted on absolute */
if (op != O_logical_not && seg_left != absolute_section
&& finalize_syms)
report_op_error (symp, NULL, op, add_symbol);
if (op == O_uminus)
left = -left;
else if (op == O_logical_not)
left = !left;
else
left = ~left;
final_val += left + symp->frag->fr_address;
resolved = symbol_resolved_p (add_symbol);
break;
case O_multiply:
case O_divide:
case O_modulus:
case O_left_shift:
case O_right_shift:
case O_bit_inclusive_or:
case O_bit_or_not:
case O_bit_exclusive_or:
case O_bit_and:
case O_add:
case O_subtract:
case O_eq:
case O_ne:
case O_lt:
case O_le:
case O_ge:
case O_gt:
case O_logical_and:
case O_logical_or:
left = resolve_symbol_value (add_symbol);
right = resolve_symbol_value (op_symbol);
seg_left = S_GET_SEGMENT (add_symbol);
seg_right = S_GET_SEGMENT (op_symbol);
/* Simplify addition or subtraction of a constant by folding the
constant into X_add_number. */
if (op == O_add)
{
if (seg_right == absolute_section)
{
final_val += right;
goto do_symbol;
}
else if (seg_left == absolute_section)
{
final_val += left;
add_symbol = op_symbol;
left = right;
seg_left = seg_right;
goto do_symbol;
}
}
else if (op == O_subtract)
{
if (seg_right == absolute_section)
{
final_val -= right;
goto do_symbol;
}
}
move_seg_ok = 1;
/* Equality and non-equality tests are permitted on anything.
Subtraction, and other comparison operators are permitted if
both operands are in the same section. Otherwise, both
operands must be absolute. We already handled the case of
addition or subtraction of a constant above. This will
probably need to be changed for an object file format which
supports arbitrary expressions. */
if (!(seg_left == absolute_section
&& seg_right == absolute_section)
&& !(op == O_eq || op == O_ne)
&& !((op == O_subtract
|| op == O_lt || op == O_le || op == O_ge || op == O_gt)
&& seg_left == seg_right
&& (seg_left != undefined_section
|| add_symbol == op_symbol)))
{
/* Don't emit messages unless we're finalizing the symbol value,
otherwise we may get the same message multiple times. */
if (finalize_syms)
report_op_error (symp, add_symbol, op, op_symbol);
/* However do not move the symbol into the absolute section
if it cannot currently be resolved - this would confuse
other parts of the assembler into believing that the
expression had been evaluated to zero. */
else
move_seg_ok = 0;
}
/* Check for division by zero. */
if ((op == O_divide || op == O_modulus) && right == 0)
{
/* If seg_right is not absolute_section, then we've
already issued a warning about using a bad symbol. */
if (seg_right == absolute_section && finalize_syms)
{
const char *file;
unsigned int line;
if (expr_symbol_where (symp, &file, &line))
as_bad_where (file, line, _("division by zero"));
else
as_bad (_("division by zero when setting `%s'"),
S_GET_NAME (symp));
}
right = 1;
}
if ((op == O_left_shift || op == O_right_shift)
&& (valueT) right >= sizeof (valueT) * CHAR_BIT)
{
as_warn_value_out_of_range (_("shift count"), right, 0,
sizeof (valueT) * CHAR_BIT - 1,
NULL, 0);
left = right = 0;
}
switch (symp->x->value.X_op)
{
case O_multiply: left *= right; break;
case O_divide: left /= right; break;
case O_modulus: left %= right; break;
case O_left_shift:
left = (valueT) left << (valueT) right; break;
case O_right_shift:
left = (valueT) left >> (valueT) right; break;
case O_bit_inclusive_or: left |= right; break;
case O_bit_or_not: left |= ~right; break;
case O_bit_exclusive_or: left ^= right; break;
case O_bit_and: left &= right; break;
case O_add: left += right; break;
case O_subtract: left -= right; break;
case O_eq:
case O_ne:
left = (left == right && seg_left == seg_right
&& (seg_left != undefined_section
|| add_symbol == op_symbol)
? ~ (offsetT) 0 : 0);
if (symp->x->value.X_op == O_ne)
left = ~left;
break;
case O_lt: left = left < right ? ~ (offsetT) 0 : 0; break;
case O_le: left = left <= right ? ~ (offsetT) 0 : 0; break;
case O_ge: left = left >= right ? ~ (offsetT) 0 : 0; break;
case O_gt: left = left > right ? ~ (offsetT) 0 : 0; break;
case O_logical_and: left = left && right; break;
case O_logical_or: left = left || right; break;
case O_illegal:
case O_absent:
case O_constant:
/* See PR 20895 for a reproducer. */
as_bad (_("Invalid operation on symbol"));
goto exit_dont_set_value;
case O_big:
case O_illegal:
/* Give an error (below) if not in expr_section. We don't
want to worry about expr_section symbols, because they
are fictional (they are created as part of expression
resolution), and any problems may not actually mean
anything. */
break;
}
symp->flags.resolving = 0;
}
if (finalize_syms)
S_SET_VALUE (symp, final_val);
exit_dont_set_value:
/* Always set the segment, even if not finalizing the value.
The segment is used to determine whether a symbol is defined. */
S_SET_SEGMENT (symp, final_seg);
/* Don't worry if we can't resolve an expr_section symbol. */
if (finalize_syms)
{
if (resolved)
symp->flags.resolved = 1;
else if (S_GET_SEGMENT (symp) != expr_section)
{
as_bad (_("can't resolve value for symbol `%s'"),
S_GET_NAME (symp));
symp->flags.resolved = 1;
}
}
return final_val;
}
/* A static function passed to hash_traverse. */
static int
resolve_local_symbol (void **slot, void *arg ATTRIBUTE_UNUSED)
{
symbol_entry_t *entry = *((symbol_entry_t **) slot);
if (entry->sy.flags.local_symbol)
resolve_symbol_value (&entry->sy);
if (!symbolP->flags.resolved && exp.X_op != O_illegal)
{
int resolved;
if (symbolP->flags.resolving)
return 0;
symbolP->flags.resolving = 1;
resolved = resolve_expression (&exp);
symbolP->flags.resolving = 0;
if (!resolved)
return 0;
switch (exp.X_op)
{
case O_constant:
case O_register:
if (!symbol_equated_p (symbolP))
break;
/* Fallthru. */
case O_symbol:
case O_symbol_rva:
symbolP = exp.X_add_symbol;
break;
default:
return 0;
}
}
*symbolPP = symbolP;
/* A bogus input file can result in resolve_expression()
generating a local symbol, so we have to check again. */
if (symbolP->flags.local_symbol)
{
struct local_symbol *locsym = (struct local_symbol *) symbolP;
if (*segP == expr_section)
switch (exp.X_op)
{
case O_constant: *segP = absolute_section; break;
case O_register: *segP = reg_section; break;
default: break;
}
}
return 1;
}
/* Dollar labels look like a number followed by a dollar sign. Eg, "42$".
They are *really* local. That is, they go out of scope whenever we see a
label that isn't local. Also, like fb labels, there can be multiple
instances of a dollar label. Therefor, we name encode each instance with
the instance number, keep a list of defined symbols separate from the real
symbol table, and we treat these buggers as a sparse array. */
/* Caller must copy returned name: we re-use the area for the next name.
The mth occurrence of label n: is turned into the symbol "Ln^Am"
where n is the label number and m is the instance number. "L" makes
it a label discarded unless debugging and "^A"('\1') ensures no
ordinary symbol SHOULD get the same name as a local label
symbol. The first "4:" is "L4^A1" - the m numbers begin at 1.
fb labels get the same treatment, except that ^B is used in place
of ^A.
AUGEND is 0 for current instance, 1 for new instance. */
char *
dollar_label_name (unsigned int n, unsigned int augend)
{
/* Returned to caller, then copied. Used for created names ("4f"). */
static char symbol_name_build[24];
char *p = symbol_name_build;
/* Somebody else's idea of local labels. They are made by "n:" where n
is any decimal digit. Refer to them with
"nb" for previous (backward) n:
or "nf" for next (forward) n:.
We do a little better and let n be any number, not just a single digit, but
since the other guy's assembler only does ten, we treat the first ten
specially.
Like someone else's assembler, we have one set of local label counters for
entire assembly, not one set per (sub)segment like in most assemblers. This
implies that one can refer to a label in another segment, and indeed some
crufty compilers have done just that.
Since there could be a LOT of these things, treat them as a sparse
array. */
/* Add one to the instance number of this fb label. */
void
fb_label_instance_inc (unsigned int label)
{
fb_ent *i;
if (label < FB_LABEL_SPECIAL)
{
++fb_low_counter[label];
return;
}
if (fb_labels != NULL)
{
for (i = fb_labels + FB_LABEL_SPECIAL;
i < fb_labels + fb_label_count; ++i)
{
if (*i == label)
{
++fb_label_instances[i - fb_labels];
return;
} /* if we find it */
} /* for each existing label */
}
/* If we get to here, we don't have label listed yet. */
static unsigned int
fb_label_instance (unsigned int label)
{
fb_ent *i;
if (label < FB_LABEL_SPECIAL)
return (fb_low_counter[label]);
if (fb_labels != NULL)
{
for (i = fb_labels + FB_LABEL_SPECIAL;
i < fb_labels + fb_label_count; ++i)
{
if (*i == label)
return (fb_label_instances[i - fb_labels]);
}
}
/* We didn't find the label, so this must be a reference to the
first instance. */
return 0;
}
/* Caller must copy returned name: we re-use the area for the next name.
The mth occurrence of label n: is turned into the symbol "Ln^Bm"
where n is the label number and m is the instance number. "L" makes
it a label discarded unless debugging and "^B"('\2') ensures no
ordinary symbol SHOULD get the same name as a local label
symbol. The first "4:" is "L4^B1" - the m numbers begin at 1.
dollar labels get the same treatment, except that ^A is used in
place of ^B.
AUGEND is 0 for nb, 1 for n:, nf. */
char *
fb_label_name (unsigned int n, unsigned int augend)
{
/* Returned to caller, then copied. Used for created names ("4f"). */
static char symbol_name_build[24];
char *p = symbol_name_build;
/* Decode name that may have been generated by foo_label_name() above.
If the name wasn't generated by foo_label_name(), then return it
unaltered. This is used for error messages. */
char *
decode_local_label_name (char *s)
{
char *p;
char *symbol_decode;
int label_number;
int instance_number;
const char *type;
const char *message_format;
int lindex = 0;
#ifdef LOCAL_LABEL_PREFIX
if (s[lindex] == LOCAL_LABEL_PREFIX)
++lindex;
#endif
if (s[lindex] != 'L')
return s;
for (label_number = 0, p = s + lindex + 1; ISDIGIT (*p); ++p)
label_number = (10 * label_number) + *p - '0';
if (*p == DOLLAR_LABEL_CHAR)
type = "dollar";
else if (*p == LOCAL_LABEL_CHAR)
type = "fb";
else
return s;
message_format = _("\"%d\" (instance number %d of a %s label)");
symbol_decode = notes_alloc (strlen (message_format) + 30);
sprintf (symbol_decode, message_format, label_number, instance_number, type);
return symbol_decode;
}
/* Get the value of a symbol. */
valueT
S_GET_VALUE_WHERE (symbolS *s, const char * file, unsigned int line)
{
if (s->flags.local_symbol)
return resolve_symbol_value (s);
if (!s->flags.resolved)
{
valueT val = resolve_symbol_value (s);
if (!finalize_syms)
return val;
}
if (S_IS_WEAKREFR (s))
return S_GET_VALUE (s->x->value.X_add_symbol);
if (s->x->value.X_op != O_constant)
{
if (! s->flags.resolved
|| s->x->value.X_op != O_symbol
|| (S_IS_DEFINED (s) && ! S_IS_COMMON (s)))
{
if (strcmp (S_GET_NAME (s), FAKE_LABEL_NAME) == 0)
as_bad_where (file, line, _("expression is too complex to be resolved or converted into relocations"));
else if (file != NULL)
as_bad_where (file, line, _("attempt to get value of unresolved symbol `%s'"),
S_GET_NAME (s));
else
as_bad (_("attempt to get value of unresolved symbol `%s'"),
S_GET_NAME (s));
}
}
return (valueT) s->x->value.X_add_number;
}
void
copy_symbol_attributes (symbolS *dest, symbolS *src)
{
if (dest->flags.local_symbol)
dest = local_symbol_convert (dest);
if (src->flags.local_symbol)
src = local_symbol_convert (src);
/* In an expression, transfer the settings of these flags.
The user can override later, of course. */
#define COPIED_SYMFLAGS (BSF_FUNCTION | BSF_OBJECT \
| BSF_GNU_INDIRECT_FUNCTION)
dest->bsym->flags |= src->bsym->flags & COPIED_SYMFLAGS;
int
S_IS_WEAK (symbolS *s)
{
if (s->flags.local_symbol)
return 0;
/* Conceptually, a weakrefr is weak if the referenced symbol is. We
could probably handle a WEAKREFR as always weak though. E.g., if
the referenced symbol has lost its weak status, there's no reason
to keep handling the weakrefr as if it was weak. */
if (S_IS_WEAKREFR (s))
return S_IS_WEAK (s->x->value.X_add_symbol);
return (s->bsym->flags & BSF_WEAK) != 0;
}
int
S_IS_WEAKREFR (symbolS *s)
{
if (s->flags.local_symbol)
return 0;
return s->flags.weakrefr != 0;
}
int
S_IS_WEAKREFD (symbolS *s)
{
if (s->flags.local_symbol)
return 0;
return s->flags.weakrefd != 0;
}
int
S_IS_COMMON (symbolS *s)
{
if (s->flags.local_symbol)
return 0;
return bfd_is_com_section (s->bsym->section);
}
int
S_IS_DEFINED (symbolS *s)
{
if (s->flags.local_symbol)
return ((struct local_symbol *) s)->section != undefined_section;
return s->bsym->section != undefined_section;
}
/* Return true for symbols that should not be reduced to section
symbols or eliminated from expressions, because they may be
overridden by the linker. */
int
S_FORCE_RELOC (symbolS *s, int strict)
{
segT sec;
if (s->flags.local_symbol)
sec = ((struct local_symbol *) s)->section;
else
{
if ((strict
&& ((s->bsym->flags & BSF_WEAK) != 0
|| (EXTERN_FORCE_RELOC
&& (s->bsym->flags & BSF_GLOBAL) != 0)))
|| (s->bsym->flags & BSF_GNU_INDIRECT_FUNCTION) != 0)
return true;
sec = s->bsym->section;
}
return bfd_is_und_section (sec) || bfd_is_com_section (sec);
}
int
S_IS_DEBUG (symbolS *s)
{
if (s->flags.local_symbol)
return 0;
if (s->bsym->flags & BSF_DEBUGGING)
return 1;
return 0;
}
int
S_IS_LOCAL (symbolS *s)
{
flagword flags;
const char *name;
if (s->flags.local_symbol)
return 1;
if (S_IS_EXTERNAL (s))
return 0;
if (bfd_asymbol_section (s->bsym) == reg_section)
return 1;
flags = s->bsym->flags;
if (flag_strip_local_absolute
/* Keep BSF_FILE symbols in order to allow debuggers to identify
the source file even when the object file is stripped. */
&& (flags & (BSF_GLOBAL | BSF_FILE)) == 0
&& bfd_asymbol_section (s->bsym) == absolute_section)
return 1;
void
S_SET_WEAKREFR (symbolS *s)
{
if (s->flags.local_symbol)
s = local_symbol_convert (s);
s->flags.weakrefr = 1;
/* If the alias was already used, make sure we mark the target as
used as well, otherwise it might be dropped from the symbol
table. This may have unintended side effects if the alias is
later redirected to another symbol, such as keeping the unused
previous target in the symbol table. Since it will be weak, it's
not a big deal. */
if (s->flags.used)
symbol_mark_used (s->x->value.X_add_symbol);
}
void
S_SET_WEAKREFD (symbolS *s)
{
if (s->flags.local_symbol)
s = local_symbol_convert (s);
s->flags.weakrefd = 1;
S_SET_WEAK (s);
}
void
S_CLEAR_WEAKREFD (symbolS *s)
{
if (s->flags.local_symbol)
return;
if (s->flags.weakrefd)
{
s->flags.weakrefd = 0;
/* If a weakref target symbol is weak, then it was never
referenced directly before, not even in a .global directive,
so decay it to local. If it remains undefined, it will be
later turned into a global, like any other undefined
symbol. */
if (s->bsym->flags & BSF_WEAK)
{
#ifdef obj_clear_weak_hook
obj_clear_weak_hook (s);
#endif
s->bsym->flags &= ~BSF_WEAK;
s->bsym->flags |= BSF_LOCAL;
}
}
}
void
S_SET_THREAD_LOCAL (symbolS *s)
{
if (s->flags.local_symbol)
s = local_symbol_convert (s);
if (bfd_is_com_section (s->bsym->section)
&& (s->bsym->flags & BSF_THREAD_LOCAL) != 0)
return;
s->bsym->flags |= BSF_THREAD_LOCAL;
if ((s->bsym->flags & BSF_FUNCTION) != 0)
as_bad (_("Accessing function `%s' as thread-local object"),
S_GET_NAME (s));
else if (! bfd_is_und_section (s->bsym->section)
&& (s->bsym->section->flags & SEC_THREAD_LOCAL) == 0)
as_bad (_("Accessing `%s' as thread-local object"),
S_GET_NAME (s));
}
int
symbol_resolved_p (symbolS *s)
{
return s->flags.resolved;
}
/* Return whether a symbol is a section symbol. */
int
symbol_section_p (symbolS *s)
{
if (s->flags.local_symbol)
return 0;
return (s->bsym->flags & BSF_SECTION_SYM) != 0;
}
/* Return whether a symbol is equated to another symbol. */
int
symbol_equated_p (symbolS *s)
{
if (s->flags.local_symbol)
return 0;
return s->x->value.X_op == O_symbol;
}
/* Return whether a symbol is equated to another symbol, and should be
treated specially when writing out relocs. */
int
symbol_equated_reloc_p (symbolS *s)
{
if (s->flags.local_symbol)
return 0;
/* X_op_symbol, normally not used for O_symbol, is set by
resolve_symbol_value to flag expression syms that have been
equated. */
return (s->x->value.X_op == O_symbol
#if defined (OBJ_COFF) && defined (TE_PE)
&& ! S_IS_WEAK (s)
#endif
&& ((s->flags.resolved && s->x->value.X_op_symbol != NULL)
|| ! S_IS_DEFINED (s)
|| S_IS_COMMON (s)));
}
/* Return whether a symbol has a constant value. */
int
symbol_constant_p (symbolS *s)
{
if (s->flags.local_symbol)
return 1;
return s->x->value.X_op == O_constant;
}
/* Return whether a symbol was cloned and thus removed from the global
symbol list. */
int
symbol_shadow_p (symbolS *s)
{
if (s->flags.local_symbol)
return 0;
return s->x->next == s;
}
/* If S is a struct symbol return S, otherwise return NULL. */
asymbol *
symbol_get_bfdsym (symbolS *s)
{
if (s->flags.local_symbol)
s = local_symbol_convert (s);
return s->bsym;
}
/* Set the BFD symbol for a symbol. */
void
symbol_set_bfdsym (symbolS *s, asymbol *bsym)
{
if (s->flags.local_symbol)
s = local_symbol_convert (s);
/* Usually, it is harmless to reset a symbol to a BFD section
symbol. For example, obj_elf_change_section sets the BFD symbol
of an old symbol with the newly created section symbol. But when
we have multiple sections with the same name, the newly created
section may have the same name as an old section. We check if the
old symbol has been already marked as a section symbol before
resetting it. */
if ((s->bsym->flags & BSF_SECTION_SYM) == 0)
s->bsym = bsym;
/* else XXX - What do we do now ? */
}
#ifdef OBJ_SYMFIELD_TYPE
/* Get a pointer to the object format information for a symbol. */
OBJ_SYMFIELD_TYPE *
symbol_get_obj (symbolS *s)
{
if (s->flags.local_symbol)
s = local_symbol_convert (s);
return &s->x->obj;
}
/* Set the object format information for a symbol. */
void
symbol_set_obj (symbolS *s, OBJ_SYMFIELD_TYPE *o)
{
if (s->flags.local_symbol)
s = local_symbol_convert (s);
s->x->obj = *o;
}
#endif /* OBJ_SYMFIELD_TYPE */
#ifdef TC_SYMFIELD_TYPE
/* Get a pointer to the processor information for a symbol. */
TC_SYMFIELD_TYPE *
symbol_get_tc (symbolS *s)
{
if (s->flags.local_symbol)
s = local_symbol_convert (s);
return &s->x->tc;
}
/* Set the processor information for a symbol. */
void
symbol_set_tc (symbolS *s, TC_SYMFIELD_TYPE *o)
{
if (s->flags.local_symbol)
s = local_symbol_convert (s);
s->x->tc = *o;
}
#endif /* TC_SYMFIELD_TYPE */
void
symbol_begin (void)
{
symbol_lastP = NULL;
symbol_rootP = NULL; /* In case we have 0 symbols (!!) */
sy_hash = htab_create_alloc (1024, hash_symbol_entry, eq_symbol_entry,
NULL, xcalloc, free);
/* Convert given symbol to a new complex-relocation symbol name. This
may be a recursive function, since it might be called for non-leaf
nodes (plain symbols) in the expression tree. The caller owns the
returning string, so should free it eventually. Errors are
indicated via as_bad and a NULL return value. The given symbol
is marked with used_in_reloc. */
/* Recurse to symbol_relc_make_expr if this symbol
is defined as an expression or a plain value. */
if ( S_GET_SEGMENT (sym) == expr_section
|| S_GET_SEGMENT (sym) == absolute_section)
return symbol_relc_make_expr (symbol_get_value_expression (sym));
/* This may be a "fake symbol", referring to ".".
Write out a special null symbol to refer to this position. */
if (! strcmp (S_GET_NAME (sym), FAKE_LABEL_NAME))
return xstrdup (".");
/* We hope this is a plain leaf symbol. Construct the encoding
as {S,s}II...:CCCCCCC....
where 'S'/'s' means section symbol / plain symbol
III is decimal for the symbol name length
CCC is the symbol name itself. */
symbol_mark_used_in_reloc (sym);
/* Convert given value to a new complex-relocation symbol name. This
is a non-recursive function, since it is be called for leaf nodes
(plain values) in the expression tree. The caller owns the
returning string, so should free() it eventually. No errors. */
char *
symbol_relc_make_value (offsetT val)
{
char * terminal = XNEWVEC (char, 28); /* Enough for long long. */
/* Convert given expression to a new complex-relocation symbol name.
This is a recursive function, since it traverses the entire given
expression tree. The caller owns the returning string, so should
free() it eventually. Errors are indicated via as_bad() and a NULL
return value. */
char *
symbol_relc_make_expr (expressionS * exp)
{
const char * opstr = NULL; /* Operator prefix string. */
int arity = 0; /* Arity of this operator. */
char * operands[3]; /* Up to three operands. */
char * concat_string = NULL;
operands[0] = operands[1] = operands[2] = NULL;
gas_assert (exp != NULL);
/* Match known operators -> fill in opstr, arity, operands[] and fall
through to construct subexpression fragments; may instead return
string directly for leaf nodes. */
/* See expr.h for the meaning of all these enums. Many operators
have an unnatural arity (X_add_number implicitly added). The
conversion logic expands them to explicit "+" subexpressions. */
case O_uminus: HANDLE_XADD_OPT1 ("0-");
case O_bit_not: HANDLE_XADD_OPT1 ("~");
case O_logical_not: HANDLE_XADD_OPT1 ("!");
case O_multiply: HANDLE_XADD_OPT2 ("*");
case O_divide: HANDLE_XADD_OPT2 ("/");
case O_modulus: HANDLE_XADD_OPT2 ("%");
case O_left_shift: HANDLE_XADD_OPT2 ("<<");
case O_right_shift: HANDLE_XADD_OPT2 (">>");
case O_bit_inclusive_or: HANDLE_XADD_OPT2 ("|");
case O_bit_exclusive_or: HANDLE_XADD_OPT2 ("^");
case O_bit_and: HANDLE_XADD_OPT2 ("&");
case O_add: HANDLE_XADD_OPT2 ("+");
case O_subtract: HANDLE_XADD_OPT2 ("-");
case O_eq: HANDLE_XADD_OPT2 ("==");
case O_ne: HANDLE_XADD_OPT2 ("!=");
case O_lt: HANDLE_XADD_OPT2 ("<");
case O_le: HANDLE_XADD_OPT2 ("<=");
case O_ge: HANDLE_XADD_OPT2 (">=");
case O_gt: HANDLE_XADD_OPT2 (">");
case O_logical_and: HANDLE_XADD_OPT2 ("&&");
case O_logical_or: HANDLE_XADD_OPT2 ("||");
}