/* 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, 2011, 2012
- Free Software Foundation, Inc.
+ Copyright (C) 1991-2014 Free Software Foundation, Inc.
Written by Steve Chamberlain of Cygnus Support <sac@cygnus.com>.
This file is part of the GNU Binutils.
{ GE, ">=" },
{ LSHIFT, "<<" },
{ RSHIFT, ">>" },
+ { LOG2CEIL, "LOG2CEIL" },
{ ALIGN_K, "ALIGN" },
{ BLOCK, "BLOCK" },
{ QUAD, "QUAD" },
}
static void
+make_log2ceil (void)
+{
+ bfd_vma value = expld.result.value;
+ bfd_vma result = -1;
+ bfd_boolean round_up = FALSE;
+
+ do
+ {
+ result++;
+ /* If more than one bit is set in the value we will need to round up. */
+ if ((value > 1) && (value & 1))
+ round_up = TRUE;
+ }
+ while (value >>= 1);
+
+ if (round_up)
+ result += 1;
+ expld.result.section = NULL;
+ expld.result.value = result;
+}
+
+static void
make_abs (void)
{
if (expld.result.section != NULL)
make_abs ();
break;
+ case LOG2CEIL:
+ make_log2ceil ();
+ break;
+
case '~':
expld.result.value = ~expld.result.value;
break;
/* Check to see if the user has overridden the default
value. */
segment_name = tree->binary.rhs->name.name;
- for (seg = segments; seg; seg = seg->next)
+ for (seg = segments; seg; seg = seg->next)
if (strcmp (seg->name, segment_name) == 0)
{
if (!seg->used
break;
case DEFINED:
- if (expld.phase == lang_first_phase_enum)
- lang_track_definedness (tree->name.name);
- else
+ if (expld.phase != lang_first_phase_enum)
{
struct bfd_link_hash_entry *h;
- int def_iteration
- = lang_symbol_definition_iteration (tree->name.name);
+ struct lang_definedness_hash_entry *def;
h = bfd_wrapped_link_hash_lookup (link_info.output_bfd,
&link_info,
&& (h->type == bfd_link_hash_defined
|| h->type == bfd_link_hash_defweak
|| h->type == bfd_link_hash_common)
- && (def_iteration == lang_statement_iteration
- || def_iteration == -1));
+ && ((def = lang_symbol_defined (tree->name.name)) == NULL
+ || def->by_object
+ || def->iteration == (lang_statement_iteration & 1)));
}
break;
case NAME:
if (expld.assign_name != NULL
&& strcmp (expld.assign_name, tree->name.name) == 0)
- expld.assign_name = NULL;
+ {
+ /* Self-assignment is only allowed for absolute symbols
+ defined in a linker script. */
+ struct bfd_link_hash_entry *h;
+ struct lang_definedness_hash_entry *def;
+
+ h = bfd_wrapped_link_hash_lookup (link_info.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)
+ && h->u.def.section == bfd_abs_section_ptr
+ && (def = lang_symbol_defined (tree->name.name)) != NULL
+ && def->iteration == (lang_statement_iteration & 1)))
+ expld.assign_name = NULL;
+ }
if (expld.phase == lang_first_phase_enum)
;
else if (tree->name.name[0] == '.' && tree->name.name[1] == 0)
/ bfd_octets_per_byte (link_info.output_bfd));
else
val = (bfd_vma)1 << os->bfd_section->alignment_power;
-
+
new_number (val);
}
else
case LENGTH:
{
lang_memory_region_type *mem;
-
- mem = lang_memory_region_lookup (tree->name.name, FALSE);
- if (mem != NULL)
+
+ mem = lang_memory_region_lookup (tree->name.name, FALSE);
+ if (mem != NULL)
new_number (mem->length);
- else
+ else
einfo (_("%F%S: undefined MEMORY region `%s'"
" referenced in expression\n"),
tree, tree->name.name);
if (expld.phase != lang_first_phase_enum)
{
lang_memory_region_type *mem;
-
- mem = lang_memory_region_lookup (tree->name.name, FALSE);
- if (mem != NULL)
+
+ mem = lang_memory_region_lookup (tree->name.name, FALSE);
+ if (mem != NULL)
new_rel_from_abs (mem->origin);
- else
+ else
einfo (_("%F%S: undefined MEMORY region `%s'"
" referenced in expression\n"),
tree, tree->name.name);
}
}
+/* Return true if TREE is '.'. */
+
+static bfd_boolean
+is_dot (const etree_type *tree)
+{
+ return (tree->type.node_class == etree_name
+ && tree->type.node_code == NAME
+ && tree->name.name[0] == '.'
+ && tree->name.name[1] == 0);
+}
+
+/* Return true if TREE is a constant equal to VAL. */
+
+static bfd_boolean
+is_value (const etree_type *tree, bfd_vma val)
+{
+ return (tree->type.node_class == etree_value
+ && tree->value.value == val);
+}
+
+/* Return true if TREE is an absolute symbol equal to VAL defined in
+ a linker script. */
+
+static bfd_boolean
+is_sym_value (const etree_type *tree, bfd_vma val)
+{
+ struct bfd_link_hash_entry *h;
+ struct lang_definedness_hash_entry *def;
+
+ return (tree->type.node_class == etree_name
+ && tree->type.node_code == NAME
+ && (def = lang_symbol_defined (tree->name.name)) != NULL
+ && def->by_script
+ && def->iteration == (lang_statement_iteration & 1)
+ && (h = bfd_wrapped_link_hash_lookup (link_info.output_bfd,
+ &link_info,
+ tree->name.name,
+ FALSE, FALSE, TRUE)) != NULL
+ && h->type == bfd_link_hash_defined
+ && h->u.def.section == bfd_abs_section_ptr
+ && h->u.def.value == val);
+}
+
+/* Return true if TREE is ". != 0". */
+
+static bfd_boolean
+is_dot_ne_0 (const etree_type *tree)
+{
+ return (tree->type.node_class == etree_binary
+ && tree->type.node_code == NE
+ && is_dot (tree->binary.lhs)
+ && is_value (tree->binary.rhs, 0));
+}
+
+/* Return true if TREE is ". = . + 0" or ". = . + sym" where sym is an
+ absolute constant with value 0 defined in a linker script. */
+
+static bfd_boolean
+is_dot_plus_0 (const etree_type *tree)
+{
+ return (tree->type.node_class == etree_binary
+ && tree->type.node_code == '+'
+ && is_dot (tree->binary.lhs)
+ && (is_value (tree->binary.rhs, 0)
+ || is_sym_value (tree->binary.rhs, 0)));
+}
+
+/* Return true if TREE is "ALIGN (. != 0 ? some_expression : 1)". */
+
+static bfd_boolean
+is_align_conditional (const etree_type *tree)
+{
+ if (tree->type.node_class == etree_unary
+ && tree->type.node_code == ALIGN_K)
+ {
+ tree = tree->unary.child;
+ return (tree->type.node_class == etree_trinary
+ && is_dot_ne_0 (tree->trinary.cond)
+ && is_value (tree->trinary.rhs, 1));
+ }
+ return 0;
+}
+
static void
exp_fold_tree_1 (etree_type *tree)
{
exp_fold_tree_1 (tree->assign.src);
expld.assigning_to_dot = FALSE;
+ /* If we are assigning to dot inside an output section
+ arrange to keep the section, except for certain
+ expressions that evaluate to zero. We ignore . = 0,
+ . = . + 0, and . = ALIGN (. != 0 ? expr : 1). */
+ if (expld.phase == lang_mark_phase_enum
+ && expld.section != bfd_abs_section_ptr
+ && !(expld.result.valid_p
+ && expld.result.value == 0
+ && (is_value (tree->assign.src, 0)
+ || is_sym_value (tree->assign.src, 0)
+ || is_dot_plus_0 (tree->assign.src)
+ || is_align_conditional (tree->assign.src))))
+ expld.section->flags |= SEC_KEEP;
+
if (!expld.result.valid_p)
{
if (expld.phase != lang_mark_phase_enum)
if (h == NULL
|| (h->type != bfd_link_hash_new
&& h->type != bfd_link_hash_undefined
- && h->type != bfd_link_hash_common))
+ && h->type != bfd_link_hash_common
+ && !(h->type == bfd_link_hash_defined
+ && (h->u.def.section->flags
+ & SEC_LINKER_CREATED) != 0)))
{
/* Do nothing. The symbol was never referenced, or was
defined by some object. */
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