/* 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" },
fputc (' ', config.map_file);
}
+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)
{
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)
+ {
+ /* 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)
}
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;
-
+ expld.assign_name = tree->assign.dst;
exp_fold_tree_1 (tree->assign.src);
- if (expld.result.valid_p
+ /* expld.assign_name remaining equal to tree->assign.dst
+ below indicates the evaluation of tree->assign.src did
+ not use the value of tree->assign.dst. We don't allow
+ self assignment until the final phase for two reasons:
+ 1) Expressions are evaluated multiple times. With
+ relaxation, the number of times may vary.
+ 2) Section relative symbol values cannot be correctly
+ converted to absolute values, as is required by many
+ expressions, until final section sizing is complete. */
+ if ((expld.result.valid_p
+ && (expld.phase == lang_final_phase_enum
+ || expld.assign_name != NULL))
|| (expld.phase <= lang_mark_phase_enum
&& tree->type.node_class == etree_assign
- && tree->assign.hidden))
+ && tree->assign.defsym))
{
if (h == NULL)
{
&& h->type == bfd_link_hash_new)
h->type = bfd_link_hash_undefined;
}
+ expld.assign_name = NULL;
}
break;
exp_assop (const char *dst,
etree_type *src,
enum node_tree_enum class,
+ bfd_boolean defsym,
bfd_boolean hidden)
{
etree_type *n;
n->assign.type.node_class = class;
n->assign.src = src;
n->assign.dst = dst;
+ n->assign.defsym = defsym;
n->assign.hidden = hidden;
return n;
}
+/* Handle linker script assignments and HIDDEN. */
+
etree_type *
-exp_assign (const char *dst, etree_type *src)
+exp_assign (const char *dst, etree_type *src, bfd_boolean hidden)
{
- return exp_assop (dst, src, etree_assign, FALSE);
+ return exp_assop (dst, src, etree_assign, FALSE, hidden);
}
+/* Handle --defsym command-line option. */
+
etree_type *
exp_defsym (const char *dst, etree_type *src)
{
- return exp_assop (dst, src, etree_assign, TRUE);
+ return exp_assop (dst, src, etree_assign, TRUE, FALSE);
}
/* Handle PROVIDE. */
etree_type *
exp_provide (const char *dst, etree_type *src, bfd_boolean hidden)
{
- return exp_assop (dst, src, etree_provide, hidden);
+ return exp_assop (dst, src, etree_provide, FALSE, hidden);
}
/* Handle ASSERT. */