/* This module handles expression trees.
Copyright 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
- 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
+ 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
Free Software Foundation, Inc.
Written by Steve Chamberlain of Cygnus Support <sac@cygnus.com>.
break;
case DATA_SEGMENT_END:
- if (expld.phase != lang_first_phase_enum
- && expld.section == bfd_abs_section_ptr
- && (expld.dataseg.phase == exp_dataseg_align_seen
- || expld.dataseg.phase == exp_dataseg_relro_seen
- || expld.dataseg.phase == exp_dataseg_adjust
- || expld.dataseg.phase == exp_dataseg_relro_adjust
- || expld.phase == lang_final_phase_enum))
+ if (expld.phase == lang_first_phase_enum
+ || expld.section != bfd_abs_section_ptr)
{
- if (expld.dataseg.phase == exp_dataseg_align_seen
- || expld.dataseg.phase == exp_dataseg_relro_seen)
- {
- expld.dataseg.phase = exp_dataseg_end_seen;
- expld.dataseg.end = expld.result.value;
- }
+ expld.result.valid_p = FALSE;
+ }
+ else if (expld.dataseg.phase == exp_dataseg_align_seen
+ || expld.dataseg.phase == exp_dataseg_relro_seen)
+ {
+ expld.dataseg.phase = exp_dataseg_end_seen;
+ expld.dataseg.end = expld.result.value;
+ }
+ else if (expld.dataseg.phase == exp_dataseg_done
+ || expld.dataseg.phase == exp_dataseg_adjust
+ || expld.dataseg.phase == exp_dataseg_relro_adjust)
+ {
+ /* OK. */
}
else
expld.result.valid_p = FALSE;
{
make_abs ();
lhs.value += lhs.section->vma;
+ lhs.section = bfd_abs_section_ptr;
}
/* If the rhs is just a number, keep the lhs section. */
else if (expld.result.section == NULL)
- expld.result.section = lhs.section;
+ {
+ expld.result.section = lhs.section;
+ /* Make this NULL so that we know one of the operands
+ was just a number, for later tests. */
+ lhs.section = NULL;
+ }
}
+ /* At this point we know that both operands have the same
+ section, or at least one of them is a plain number. */
switch (tree->type.node_code)
{
- case '%':
- if (expld.result.value != 0)
- expld.result.value = ((bfd_signed_vma) lhs.value
- % (bfd_signed_vma) expld.result.value);
- else if (expld.phase != lang_mark_phase_enum)
- einfo (_("%F%S %% by zero\n"));
- break;
-
- case '/':
- if (expld.result.value != 0)
- expld.result.value = ((bfd_signed_vma) lhs.value
- / (bfd_signed_vma) expld.result.value);
- else if (expld.phase != lang_mark_phase_enum)
- einfo (_("%F%S / by zero\n"));
- break;
-
+ /* Arithmetic operators, bitwise AND, bitwise OR and XOR
+ keep the section of one of their operands only when the
+ other operand is a plain number. Losing the section when
+ operating on two symbols, ie. a result of a plain number,
+ is required for subtraction and XOR. It's justifiable
+ for the other operations on the grounds that adding,
+ multiplying etc. two section relative values does not
+ really make sense unless they are just treated as
+ numbers.
+ The same argument could be made for many expressions
+ involving one symbol and a number. For example,
+ "1 << x" and "100 / x" probably should not be given the
+ section of x. The trouble is that if we fuss about such
+ things the rules become complex and it is onerous to
+ document ld expression evaluation. */
#define BOP(x, y) \
case x: \
expld.result.value = lhs.value y expld.result.value; \
+ if (expld.result.section == lhs.section) \
+ expld.result.section = NULL; \
break;
+ /* Comparison operators, logical AND, and logical OR always
+ return a plain number. */
#define BOPN(x, y) \
case x: \
expld.result.value = lhs.value y expld.result.value; \
BOPN (ANDAND, &&);
BOPN (OROR, ||);
+ case '%':
+ if (expld.result.value != 0)
+ expld.result.value = ((bfd_signed_vma) lhs.value
+ % (bfd_signed_vma) expld.result.value);
+ else if (expld.phase != lang_mark_phase_enum)
+ einfo (_("%F%S %% by zero\n"));
+ if (expld.result.section == lhs.section)
+ expld.result.section = NULL;
+ break;
+
+ case '/':
+ if (expld.result.value != 0)
+ expld.result.value = ((bfd_signed_vma) lhs.value
+ / (bfd_signed_vma) expld.result.value);
+ else if (expld.phase != lang_mark_phase_enum)
+ einfo (_("%F%S / by zero\n"));
+ if (expld.result.section == lhs.section)
+ expld.result.section = NULL;
+ break;
+
case MAX_K:
if (lhs.value > expld.result.value)
expld.result.value = lhs.value;
case DATA_SEGMENT_ALIGN:
expld.dataseg.relro = exp_dataseg_relro_start;
- if (expld.phase != lang_first_phase_enum
- && expld.section == bfd_abs_section_ptr
- && (expld.dataseg.phase == exp_dataseg_none
- || expld.dataseg.phase == exp_dataseg_adjust
- || expld.dataseg.phase == exp_dataseg_relro_adjust
- || expld.phase == lang_final_phase_enum))
+ if (expld.phase == lang_first_phase_enum
+ || expld.section != bfd_abs_section_ptr)
+ expld.result.valid_p = FALSE;
+ else
{
bfd_vma maxpage = lhs.value;
bfd_vma commonpage = expld.result.value;
expld.result.value = align_n (expld.dot, maxpage);
if (expld.dataseg.phase == exp_dataseg_relro_adjust)
expld.result.value = expld.dataseg.base;
- else if (expld.dataseg.phase != exp_dataseg_adjust)
+ else if (expld.dataseg.phase == exp_dataseg_adjust)
+ {
+ if (commonpage < maxpage)
+ expld.result.value += ((expld.dot + commonpage - 1)
+ & (maxpage - commonpage));
+ }
+ else
{
expld.result.value += expld.dot & (maxpage - 1);
- if (expld.phase == lang_allocating_phase_enum)
+ if (expld.dataseg.phase == exp_dataseg_done)
+ {
+ /* OK. */
+ }
+ else if (expld.dataseg.phase == exp_dataseg_none)
{
expld.dataseg.phase = exp_dataseg_align_seen;
expld.dataseg.min_base = expld.dot;
expld.dataseg.maxpagesize = maxpage;
expld.dataseg.relro_end = 0;
}
+ else
+ expld.result.valid_p = FALSE;
}
- else if (commonpage < maxpage)
- expld.result.value += ((expld.dot + commonpage - 1)
- & (maxpage - commonpage));
}
- else
- expld.result.valid_p = FALSE;
break;
case DATA_SEGMENT_RELRO_END:
expld.dataseg.relro = exp_dataseg_relro_end;
- if (expld.phase != lang_first_phase_enum
- && (expld.dataseg.phase == exp_dataseg_align_seen
- || expld.dataseg.phase == exp_dataseg_adjust
- || expld.dataseg.phase == exp_dataseg_relro_adjust
- || expld.phase == lang_final_phase_enum))
+ if (expld.phase == lang_first_phase_enum
+ || expld.section != bfd_abs_section_ptr)
+ expld.result.valid_p = FALSE;
+ else if (expld.dataseg.phase == exp_dataseg_align_seen
+ || expld.dataseg.phase == exp_dataseg_adjust
+ || expld.dataseg.phase == exp_dataseg_relro_adjust
+ || expld.dataseg.phase == exp_dataseg_done)
{
if (expld.dataseg.phase == exp_dataseg_align_seen
|| expld.dataseg.phase == exp_dataseg_relro_adjust)
break;
case DEFINED:
- expld.uses_defined = TRUE;
if (expld.phase == lang_first_phase_enum)
lang_track_definedness (tree->name.name);
else
" referenced in expression\n"),
tree->name.name);
}
- else if (output_section == bfd_abs_section_ptr)
+ else if (output_section == bfd_abs_section_ptr
+ && (expld.section != bfd_abs_section_ptr
+ || config.sane_expr))
new_number (h->u.def.value + h->u.def.section->output_offset);
else
new_rel (h->u.def.value + h->u.def.section->output_offset,
switch (tree->type.node_class)
{
case etree_value:
- new_number (tree->value.value);
+ if (expld.section == bfd_abs_section_ptr
+ && !config.sane_expr)
+ new_abs (tree->value.value);
+ else
+ new_number (tree->value.value);
expld.result.str = tree->value.str;
break;
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"));
+ /* After allocation, assignment to dot should not be done inside
+ an output section since allocation adds a padding statement
+ that effectively duplicates the assignment. */
if (expld.phase == lang_mark_phase_enum
|| expld.phase == lang_allocating_phase_enum
- || (expld.phase == lang_final_phase_enum
+ || ((expld.phase == lang_assigning_phase_enum
+ || expld.phase == lang_final_phase_enum)
&& expld.section == bfd_abs_section_ptr))
{
/* Notify the folder that this is an assignment to dot. */
}
else
{
+ etree_type *name;
+
struct bfd_link_hash_entry *h = NULL;
if (tree->type.node_class == etree_provide)
}
}
+ name = tree->assign.src;
+ if (name->type.node_class == etree_trinary)
+ {
+ exp_fold_tree_1 (name->trinary.cond);
+ if (expld.result.valid_p)
+ name = (expld.result.value
+ ? name->trinary.lhs : name->trinary.rhs);
+ }
+
+ if (name->type.node_class == etree_name
+ && name->type.node_code == NAME
+ && strcmp (tree->assign.dst, name->name.name) == 0)
+ /* Leave it alone. Do not replace a symbol with its own
+ output address, in case there is another section sizing
+ pass. Folding does not preserve input sections. */
+ break;
+
exp_fold_tree_1 (tree->assign.src);
if (expld.result.valid_p
|| (expld.phase == lang_first_phase_enum
- && !expld.uses_defined))
+ && tree->type.node_class == etree_assign
+ && tree->assign.hidden))
{
if (h == NULL)
{
tree->type.node_class = etree_provided;
/* Copy the symbol type if this is a simple assignment of
- one symbol to annother. */
+ one symbol to another. This could be more general
+ (e.g. a ?: operator with NAMEs in each branch). */
if (tree->assign.src->type.node_class == etree_name)
{
struct bfd_link_hash_entry *hsrc;
memset (&expld.result, 0, sizeof (expld.result));
break;
}
-
- /* Any value not inside an output section statement is an
- absolute value. */
- if (expld.result.valid_p
- && expld.section == bfd_abs_section_ptr)
- make_abs ();
}
void
expld.dot = *dotp;
expld.dotp = dotp;
expld.section = current_section;
- expld.uses_defined = FALSE;
exp_fold_tree_1 (tree);
}
expld.dot = 0;
expld.dotp = NULL;
expld.section = bfd_abs_section_ptr;
- expld.uses_defined = FALSE;
exp_fold_tree_1 (tree);
}
}
-etree_type *
-exp_assop (int code, const char *dst, etree_type *src)
-{
- etree_type *new_e;
-
- new_e = (etree_type *) stat_alloc (sizeof (new_e->assign));
- new_e->type.node_code = code;
- new_e->type.lineno = src->type.lineno;
- new_e->type.node_class = etree_assign;
- new_e->assign.src = src;
- new_e->assign.dst = dst;
- return new_e;
-}
-
-/* Handle PROVIDE. */
-
-etree_type *
-exp_provide (const char *dst, etree_type *src, bfd_boolean hidden)
+static etree_type *
+exp_assop (const char *dst,
+ etree_type *src,
+ enum node_tree_enum class,
+ bfd_boolean hidden)
{
etree_type *n;
n = (etree_type *) stat_alloc (sizeof (n->assign));
n->assign.type.node_code = '=';
n->assign.type.lineno = src->type.lineno;
- n->assign.type.node_class = etree_provide;
+ n->assign.type.node_class = class;
n->assign.src = src;
n->assign.dst = dst;
n->assign.hidden = hidden;
return n;
}
+etree_type *
+exp_assign (const char *dst, etree_type *src)
+{
+ return exp_assop (dst, src, etree_assign, FALSE);
+}
+
+etree_type *
+exp_defsym (const char *dst, etree_type *src)
+{
+ return exp_assop (dst, src, etree_assign, TRUE);
+}
+
+/* Handle PROVIDE. */
+
+etree_type *
+exp_provide (const char *dst, etree_type *src, bfd_boolean hidden)
+{
+ return exp_assop (dst, src, etree_provide, hidden);
+}
+
/* Handle ASSERT. */
etree_type *