binutils-gdb/ld/ldexp.c

997 lines
24 KiB
C

/* This module handles expression trees.
Copyright 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
2001
Free Software Foundation, Inc.
Written by Steve Chamberlain of Cygnus Support <sac@cygnus.com>.
This file is part of GLD, the Gnu Linker.
GLD 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 2, or (at your option)
any later version.
GLD 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 GLD; see the file COPYING. If not, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA. */
/* This module is in charge of working out the contents of expressions.
It has to keep track of the relative/absness of a symbol etc. This
is done by keeping all values in a struct (an etree_value_type)
which contains a value, a section to which it is relative and a
valid bit. */
#include "bfd.h"
#include "sysdep.h"
#include "bfdlink.h"
#include "ld.h"
#include "ldmain.h"
#include "ldmisc.h"
#include "ldexp.h"
#include "ldgram.h"
#include "ldlang.h"
#include "libiberty.h"
static void exp_print_token PARAMS ((token_code_type code));
static void make_abs PARAMS ((etree_value_type *ptr));
static etree_value_type new_abs PARAMS ((bfd_vma value));
static void check PARAMS ((lang_output_section_statement_type *os,
const char *name, const char *op));
static etree_value_type new_rel
PARAMS ((bfd_vma value, lang_output_section_statement_type *section));
static etree_value_type new_rel_from_section
PARAMS ((bfd_vma value, lang_output_section_statement_type *section));
static etree_value_type fold_binary
PARAMS ((etree_type *tree,
lang_output_section_statement_type *current_section,
lang_phase_type allocation_done,
bfd_vma dot, bfd_vma *dotp));
static etree_value_type fold_name
PARAMS ((etree_type *tree,
lang_output_section_statement_type *current_section,
lang_phase_type allocation_done,
bfd_vma dot));
static etree_value_type exp_fold_tree_no_dot
PARAMS ((etree_type *tree,
lang_output_section_statement_type *current_section,
lang_phase_type allocation_done));
static void
exp_print_token (code)
token_code_type code;
{
static CONST struct
{
token_code_type code;
char * name;
}
table[] =
{
{ INT, "int" },
{ NAME, "NAME" },
{ PLUSEQ, "+=" },
{ MINUSEQ, "-=" },
{ MULTEQ, "*=" },
{ DIVEQ, "/=" },
{ LSHIFTEQ, "<<=" },
{ RSHIFTEQ, ">>=" },
{ ANDEQ, "&=" },
{ OREQ, "|=" },
{ OROR, "||" },
{ ANDAND, "&&" },
{ EQ, "==" },
{ NE, "!=" },
{ LE, "<=" },
{ GE, ">=" },
{ LSHIFT, "<<" },
{ RSHIFT, ">>" },
{ ALIGN_K, "ALIGN" },
{ BLOCK, "BLOCK" },
{ QUAD, "QUAD" },
{ SQUAD, "SQUAD" },
{ LONG, "LONG" },
{ SHORT, "SHORT" },
{ BYTE, "BYTE" },
{ SECTIONS, "SECTIONS" },
{ SIZEOF_HEADERS, "SIZEOF_HEADERS" },
{ MEMORY, "MEMORY" },
{ DEFINED, "DEFINED" },
{ TARGET_K, "TARGET" },
{ SEARCH_DIR, "SEARCH_DIR" },
{ MAP, "MAP" },
{ ENTRY, "ENTRY" },
{ NEXT, "NEXT" },
{ SIZEOF, "SIZEOF" },
{ ADDR, "ADDR" },
{ LOADADDR, "LOADADDR" },
{ MAX_K, "MAX_K" },
{ REL, "relocateable" },
};
unsigned int idx;
for (idx = ARRAY_SIZE (table); idx--;)
{
if (table[idx].code == code)
{
fprintf (config.map_file, " %s ", table[idx].name);
return;
}
}
/* Not in table, just print it alone. */
if (code < 127)
fprintf (config.map_file, " %c ", code);
else
fprintf (config.map_file, " <code %d> ", code);
}
static void
make_abs (ptr)
etree_value_type *ptr;
{
asection *s = ptr->section->bfd_section;
ptr->value += s->vma;
ptr->section = abs_output_section;
}
static etree_value_type
new_abs (value)
bfd_vma value;
{
etree_value_type new;
new.valid_p = true;
new.section = abs_output_section;
new.value = value;
return new;
}
static void
check (os, name, op)
lang_output_section_statement_type *os;
const char *name;
const char *op;
{
if (os == NULL)
einfo (_("%F%P: %s uses undefined section %s\n"), op, name);
if (! os->processed)
einfo (_("%F%P: %s forward reference of section %s\n"), op, name);
}
etree_type *
exp_intop (value)
bfd_vma value;
{
etree_type *new = (etree_type *) stat_alloc (sizeof (new->value));
new->type.node_code = INT;
new->value.value = value;
new->type.node_class = etree_value;
return new;
}
/* Build an expression representing an unnamed relocateable value. */
etree_type *
exp_relop (section, value)
asection *section;
bfd_vma value;
{
etree_type *new = (etree_type *) stat_alloc (sizeof (new->rel));
new->type.node_code = REL;
new->type.node_class = etree_rel;
new->rel.section = section;
new->rel.value = value;
return new;
}
static etree_value_type
new_rel (value, section)
bfd_vma value;
lang_output_section_statement_type *section;
{
etree_value_type new;
new.valid_p = true;
new.value = value;
new.section = section;
return new;
}
static etree_value_type
new_rel_from_section (value, section)
bfd_vma value;
lang_output_section_statement_type *section;
{
etree_value_type new;
new.valid_p = true;
new.value = value;
new.section = section;
new.value -= section->bfd_section->vma;
return new;
}
static etree_value_type
fold_binary (tree, current_section, allocation_done, dot, dotp)
etree_type *tree;
lang_output_section_statement_type *current_section;
lang_phase_type allocation_done;
bfd_vma dot;
bfd_vma *dotp;
{
etree_value_type result;
result = exp_fold_tree (tree->binary.lhs, current_section,
allocation_done, dot, dotp);
if (result.valid_p)
{
etree_value_type other;
other = exp_fold_tree (tree->binary.rhs,
current_section,
allocation_done, dot, dotp);
if (other.valid_p)
{
/* If the values are from different sections, or this is an
absolute expression, make both the source arguments
absolute. However, adding or subtracting an absolute
value from a relative value is meaningful, and is an
exception. */
if (current_section != abs_output_section
&& (other.section == abs_output_section
|| (result.section == abs_output_section
&& tree->type.node_code == '+'))
&& (tree->type.node_code == '+'
|| tree->type.node_code == '-'))
{
etree_value_type hold;
/* If there is only one absolute term, make sure it is the
second one. */
if (other.section != abs_output_section)
{
hold = result;
result = other;
other = hold;
}
}
else if (result.section != other.section
|| current_section == abs_output_section)
{
make_abs (&result);
make_abs (&other);
}
switch (tree->type.node_code)
{
case '%':
if (other.value == 0)
einfo (_("%F%S %% by zero\n"));
result.value = ((bfd_signed_vma) result.value
% (bfd_signed_vma) other.value);
break;
case '/':
if (other.value == 0)
einfo (_("%F%S / by zero\n"));
result.value = ((bfd_signed_vma) result.value
/ (bfd_signed_vma) other.value);
break;
#define BOP(x,y) case x : result.value = result.value y other.value; break;
BOP ('+', +);
BOP ('*', *);
BOP ('-', -);
BOP (LSHIFT, <<);
BOP (RSHIFT, >>);
BOP (EQ, ==);
BOP (NE, !=);
BOP ('<', <);
BOP ('>', >);
BOP (LE, <=);
BOP (GE, >=);
BOP ('&', &);
BOP ('^', ^);
BOP ('|', |);
BOP (ANDAND, &&);
BOP (OROR, ||);
case MAX_K:
if (result.value < other.value)
result = other;
break;
case MIN_K:
if (result.value > other.value)
result = other;
break;
default:
FAIL ();
}
}
else
{
result.valid_p = false;
}
}
return result;
}
etree_value_type
invalid ()
{
etree_value_type new;
new.valid_p = false;
return new;
}
static etree_value_type
fold_name (tree, current_section, allocation_done, dot)
etree_type *tree;
lang_output_section_statement_type *current_section;
lang_phase_type allocation_done;
bfd_vma dot;
{
etree_value_type result;
switch (tree->type.node_code)
{
case SIZEOF_HEADERS:
if (allocation_done != lang_first_phase_enum)
{
result = new_abs ((bfd_vma)
bfd_sizeof_headers (output_bfd,
link_info.relocateable));
}
else
{
result.valid_p = false;
}
break;
case DEFINED:
if (allocation_done == lang_first_phase_enum)
result.valid_p = false;
else
{
struct bfd_link_hash_entry *h;
h = bfd_wrapped_link_hash_lookup (output_bfd, &link_info,
tree->name.name,
false, false, true);
result.value = (h != (struct bfd_link_hash_entry *) NULL
&& (h->type == bfd_link_hash_defined
|| h->type == bfd_link_hash_defweak
|| h->type == bfd_link_hash_common));
result.section = 0;
result.valid_p = true;
}
break;
case NAME:
result.valid_p = false;
if (tree->name.name[0] == '.' && tree->name.name[1] == 0)
{
if (allocation_done != lang_first_phase_enum)
result = new_rel_from_section (dot, current_section);
else
result = invalid ();
}
else if (allocation_done != lang_first_phase_enum)
{
struct bfd_link_hash_entry *h;
h = bfd_wrapped_link_hash_lookup (output_bfd, &link_info,
tree->name.name,
false, false, true);
if (h != NULL
&& (h->type == bfd_link_hash_defined
|| h->type == bfd_link_hash_defweak))
{
if (bfd_is_abs_section (h->u.def.section))
result = new_abs (h->u.def.value);
else if (allocation_done == lang_final_phase_enum
|| allocation_done == lang_allocating_phase_enum)
{
asection *output_section;
output_section = h->u.def.section->output_section;
if (output_section == NULL)
einfo (_("%X%S: unresolvable symbol `%s' referenced in expression\n"),
tree->name.name);
else
{
lang_output_section_statement_type *os;
os = (lang_output_section_statement_lookup
(bfd_get_section_name (output_bfd,
output_section)));
/* FIXME: Is this correct if this section is
being linked with -R? */
result = new_rel ((h->u.def.value
+ h->u.def.section->output_offset),
os);
}
}
}
else if (allocation_done == lang_final_phase_enum)
einfo (_("%F%S: undefined symbol `%s' referenced in expression\n"),
tree->name.name);
}
break;
case ADDR:
if (allocation_done != lang_first_phase_enum)
{
lang_output_section_statement_type *os;
os = lang_output_section_find (tree->name.name);
check (os, tree->name.name, "ADDR");
result = new_rel (0, os);
}
else
result = invalid ();
break;
case LOADADDR:
if (allocation_done != lang_first_phase_enum)
{
lang_output_section_statement_type *os;
os = lang_output_section_find (tree->name.name);
check (os, tree->name.name, "LOADADDR");
if (os->load_base == NULL)
result = new_rel (0, os);
else
result = exp_fold_tree_no_dot (os->load_base,
abs_output_section,
allocation_done);
}
else
result = invalid ();
break;
case SIZEOF:
if (allocation_done != lang_first_phase_enum)
{
int opb = bfd_octets_per_byte (output_bfd);
lang_output_section_statement_type *os;
os = lang_output_section_find (tree->name.name);
check (os, tree->name.name, "SIZEOF");
result = new_abs (os->bfd_section->_raw_size / opb);
}
else
result = invalid ();
break;
default:
FAIL ();
break;
}
return result;
}
etree_value_type
exp_fold_tree (tree, current_section, allocation_done, dot, dotp)
etree_type *tree;
lang_output_section_statement_type *current_section;
lang_phase_type allocation_done;
bfd_vma dot;
bfd_vma *dotp;
{
etree_value_type result;
if (tree == NULL)
{
result.valid_p = false;
return result;
}
switch (tree->type.node_class)
{
case etree_value:
result = new_rel (tree->value.value, current_section);
break;
case etree_rel:
if (allocation_done != lang_final_phase_enum)
result.valid_p = false;
else
result = new_rel ((tree->rel.value
+ tree->rel.section->output_section->vma
+ tree->rel.section->output_offset),
current_section);
break;
case etree_assert:
result = exp_fold_tree (tree->assert_s.child,
current_section,
allocation_done, dot, dotp);
if (result.valid_p)
{
if (! result.value)
einfo ("%F%P: %s\n", tree->assert_s.message);
return result;
}
break;
case etree_unary:
result = exp_fold_tree (tree->unary.child,
current_section,
allocation_done, dot, dotp);
if (result.valid_p)
{
switch (tree->type.node_code)
{
case ALIGN_K:
if (allocation_done != lang_first_phase_enum)
result = new_rel_from_section (ALIGN_N (dot, result.value),
current_section);
else
result.valid_p = false;
break;
case ABSOLUTE:
if (allocation_done != lang_first_phase_enum && result.valid_p)
{
result.value += result.section->bfd_section->vma;
result.section = abs_output_section;
}
else
result.valid_p = false;
break;
case '~':
make_abs (&result);
result.value = ~result.value;
break;
case '!':
make_abs (&result);
result.value = !result.value;
break;
case '-':
make_abs (&result);
result.value = -result.value;
break;
case NEXT:
/* Return next place aligned to value. */
if (allocation_done == lang_allocating_phase_enum)
{
make_abs (&result);
result.value = ALIGN_N (dot, result.value);
}
else
result.valid_p = false;
break;
default:
FAIL ();
break;
}
}
break;
case etree_trinary:
result = exp_fold_tree (tree->trinary.cond, current_section,
allocation_done, dot, dotp);
if (result.valid_p)
result = exp_fold_tree ((result.value
? tree->trinary.lhs
: tree->trinary.rhs),
current_section,
allocation_done, dot, dotp);
break;
case etree_binary:
result = fold_binary (tree, current_section, allocation_done,
dot, dotp);
break;
case etree_assign:
case etree_provide:
case etree_provided:
if (tree->assign.dst[0] == '.' && tree->assign.dst[1] == 0)
{
/* Assignment to dot can only be done during allocation. */
if (tree->type.node_class != etree_assign)
einfo (_("%F%S can not PROVIDE assignment to location counter\n"));
if (allocation_done == lang_allocating_phase_enum
|| (allocation_done == lang_final_phase_enum
&& current_section == abs_output_section))
{
result = exp_fold_tree (tree->assign.src,
current_section,
lang_allocating_phase_enum, dot,
dotp);
if (! result.valid_p)
einfo (_("%F%S invalid assignment to location counter\n"));
else
{
if (current_section == NULL)
einfo (_("%F%S assignment to location counter invalid outside of SECTION\n"));
else
{
bfd_vma nextdot;
nextdot = (result.value
+ current_section->bfd_section->vma);
if (nextdot < dot
&& current_section != abs_output_section)
einfo (_("%F%S cannot move location counter backwards (from %V to %V)\n"),
dot, nextdot);
else
*dotp = nextdot;
}
}
}
}
else
{
result = exp_fold_tree (tree->assign.src,
current_section, allocation_done,
dot, dotp);
if (result.valid_p)
{
boolean create;
struct bfd_link_hash_entry *h;
if (tree->type.node_class == etree_assign)
create = true;
else
create = false;
h = bfd_link_hash_lookup (link_info.hash, tree->assign.dst,
create, false, false);
if (h == (struct bfd_link_hash_entry *) NULL)
{
if (tree->type.node_class == etree_assign)
einfo (_("%P%F:%s: hash creation failed\n"),
tree->assign.dst);
}
else if (tree->type.node_class == etree_provide
&& h->type != bfd_link_hash_undefined
&& h->type != bfd_link_hash_common)
{
/* Do nothing. The symbol was defined by some
object. */
}
else
{
/* FIXME: Should we worry if the symbol is already
defined? */
h->type = bfd_link_hash_defined;
h->u.def.value = result.value;
h->u.def.section = result.section->bfd_section;
if (tree->type.node_class == etree_provide)
tree->type.node_class = etree_provided;
}
}
}
break;
case etree_name:
result = fold_name (tree, current_section, allocation_done, dot);
break;
default:
FAIL ();
break;
}
return result;
}
static etree_value_type
exp_fold_tree_no_dot (tree, current_section, allocation_done)
etree_type *tree;
lang_output_section_statement_type *current_section;
lang_phase_type allocation_done;
{
return exp_fold_tree (tree, current_section, allocation_done,
(bfd_vma) 0, (bfd_vma *) NULL);
}
etree_type *
exp_binop (code, lhs, rhs)
int code;
etree_type *lhs;
etree_type *rhs;
{
etree_type value, *new;
etree_value_type r;
value.type.node_code = code;
value.binary.lhs = lhs;
value.binary.rhs = rhs;
value.type.node_class = etree_binary;
r = exp_fold_tree_no_dot (&value,
abs_output_section,
lang_first_phase_enum);
if (r.valid_p)
{
return exp_intop (r.value);
}
new = (etree_type *) stat_alloc (sizeof (new->binary));
memcpy ((char *) new, (char *) &value, sizeof (new->binary));
return new;
}
etree_type *
exp_trinop (code, cond, lhs, rhs)
int code;
etree_type *cond;
etree_type *lhs;
etree_type *rhs;
{
etree_type value, *new;
etree_value_type r;
value.type.node_code = code;
value.trinary.lhs = lhs;
value.trinary.cond = cond;
value.trinary.rhs = rhs;
value.type.node_class = etree_trinary;
r = exp_fold_tree_no_dot (&value,
(lang_output_section_statement_type *) NULL,
lang_first_phase_enum);
if (r.valid_p)
return exp_intop (r.value);
new = (etree_type *) stat_alloc (sizeof (new->trinary));
memcpy ((char *) new, (char *) &value, sizeof (new->trinary));
return new;
}
etree_type *
exp_unop (code, child)
int code;
etree_type *child;
{
etree_type value, *new;
etree_value_type r;
value.unary.type.node_code = code;
value.unary.child = child;
value.unary.type.node_class = etree_unary;
r = exp_fold_tree_no_dot (&value, abs_output_section,
lang_first_phase_enum);
if (r.valid_p)
return exp_intop (r.value);
new = (etree_type *) stat_alloc (sizeof (new->unary));
memcpy ((char *) new, (char *) &value, sizeof (new->unary));
return new;
}
etree_type *
exp_nameop (code, name)
int code;
CONST char *name;
{
etree_type value, *new;
etree_value_type r;
value.name.type.node_code = code;
value.name.name = name;
value.name.type.node_class = etree_name;
r = exp_fold_tree_no_dot (&value,
(lang_output_section_statement_type *) NULL,
lang_first_phase_enum);
if (r.valid_p)
return exp_intop (r.value);
new = (etree_type *) stat_alloc (sizeof (new->name));
memcpy ((char *) new, (char *) &value, sizeof (new->name));
return new;
}
etree_type *
exp_assop (code, dst, src)
int code;
CONST char *dst;
etree_type *src;
{
etree_type value, *new;
value.assign.type.node_code = code;
value.assign.src = src;
value.assign.dst = dst;
value.assign.type.node_class = etree_assign;
#if 0
if (exp_fold_tree_no_dot (&value, &result))
return exp_intop (result);
#endif
new = (etree_type *) stat_alloc (sizeof (new->assign));
memcpy ((char *) new, (char *) &value, sizeof (new->assign));
return new;
}
/* Handle PROVIDE. */
etree_type *
exp_provide (dst, src)
const char *dst;
etree_type *src;
{
etree_type *n;
n = (etree_type *) stat_alloc (sizeof (n->assign));
n->assign.type.node_code = '=';
n->assign.type.node_class = etree_provide;
n->assign.src = src;
n->assign.dst = dst;
return n;
}
/* Handle ASSERT. */
etree_type *
exp_assert (exp, message)
etree_type *exp;
const char *message;
{
etree_type *n;
n = (etree_type *) stat_alloc (sizeof (n->assert_s));
n->assert_s.type.node_code = '!';
n->assert_s.type.node_class = etree_assert;
n->assert_s.child = exp;
n->assert_s.message = message;
return n;
}
void
exp_print_tree (tree)
etree_type *tree;
{
if (config.map_file == NULL)
config.map_file = stderr;
if (tree == NULL)
{
minfo ("NULL TREE\n");
return;
}
switch (tree->type.node_class)
{
case etree_value:
minfo ("0x%v", tree->value.value);
return;
case etree_rel:
if (tree->rel.section->owner != NULL)
minfo ("%B:", tree->rel.section->owner);
minfo ("%s+0x%v", tree->rel.section->name, tree->rel.value);
return;
case etree_assign:
#if 0
if (tree->assign.dst->sdefs != (asymbol *) NULL)
fprintf (config.map_file, "%s (%x) ", tree->assign.dst->name,
tree->assign.dst->sdefs->value);
else
fprintf (config.map_file, "%s (UNDEFINED)", tree->assign.dst->name);
#endif
fprintf (config.map_file, "%s", tree->assign.dst);
exp_print_token (tree->type.node_code);
exp_print_tree (tree->assign.src);
break;
case etree_provide:
case etree_provided:
fprintf (config.map_file, "PROVIDE (%s, ", tree->assign.dst);
exp_print_tree (tree->assign.src);
fprintf (config.map_file, ")");
break;
case etree_binary:
fprintf (config.map_file, "(");
exp_print_tree (tree->binary.lhs);
exp_print_token (tree->type.node_code);
exp_print_tree (tree->binary.rhs);
fprintf (config.map_file, ")");
break;
case etree_trinary:
exp_print_tree (tree->trinary.cond);
fprintf (config.map_file, "?");
exp_print_tree (tree->trinary.lhs);
fprintf (config.map_file, ":");
exp_print_tree (tree->trinary.rhs);
break;
case etree_unary:
exp_print_token (tree->unary.type.node_code);
if (tree->unary.child)
{
fprintf (config.map_file, "(");
exp_print_tree (tree->unary.child);
fprintf (config.map_file, ")");
}
break;
case etree_assert:
fprintf (config.map_file, "ASSERT (");
exp_print_tree (tree->assert_s.child);
fprintf (config.map_file, ", %s)", tree->assert_s.message);
break;
case etree_undef:
fprintf (config.map_file, "????????");
break;
case etree_name:
if (tree->type.node_code == NAME)
{
fprintf (config.map_file, "%s", tree->name.name);
}
else
{
exp_print_token (tree->type.node_code);
if (tree->name.name)
fprintf (config.map_file, "(%s)", tree->name.name);
}
break;
default:
FAIL ();
break;
}
}
bfd_vma
exp_get_vma (tree, def, name, allocation_done)
etree_type *tree;
bfd_vma def;
char *name;
lang_phase_type allocation_done;
{
etree_value_type r;
if (tree != NULL)
{
r = exp_fold_tree_no_dot (tree, abs_output_section, allocation_done);
if (! r.valid_p && name != NULL)
einfo (_("%F%S nonconstant expression for %s\n"), name);
return r.value;
}
else
return def;
}
int
exp_get_value_int (tree, def, name, allocation_done)
etree_type *tree;
int def;
char *name;
lang_phase_type allocation_done;
{
return (int) exp_get_vma (tree, (bfd_vma) def, name, allocation_done);
}
bfd_vma
exp_get_abs_int (tree, def, name, allocation_done)
etree_type *tree;
int def ATTRIBUTE_UNUSED;
char *name;
lang_phase_type allocation_done;
{
etree_value_type res;
res = exp_fold_tree_no_dot (tree, abs_output_section, allocation_done);
if (res.valid_p)
res.value += res.section->bfd_section->vma;
else
einfo (_("%F%S non constant expression for %s\n"), name);
return res.value;
}