* ld.texinfo (Builtin Functions) <DEFINED>: Say that only symbols
defined before the statement using DEFINED yield 1. * ldexp.c (fold_name) <case DEFINED>: In lang_first_phase_enum, call lang_track_definedness on symbol. In subsequent phases, use lang_symbol_definition_iteration and lang_statement_iteration to check whether the symbol was defined before the current statement. (exp_fold_tree) <case etree_assign et al>: Call lang_update_definedness before updating symbol type when setting symbol. * ldlang.c (lang_definedness_table): New variable. (lang_definedness_newfunc, lang_track_definedness) (lang_symbol_definition_iteration, lang_update_definedness): New functions. (lang_init): Initialize lang_definedness_table and lang_statement_iteration. (lang_finish): Destroy bfd_hash_table_free. (lang_size_sections): Increment lang_statement_iteration. (lang_do_assignments_1): New function with former lang_do_assignments contents. Change recursive calls to call this function. (lang_do_assignments): Evacuate contents. Increment lang_statement_iteration, then just call lang_do_assignments_1. * ldlang.h (struct lang_definedness_hash_entry) (lang_statement_iteration, lang_track_definedness) (lang_symbol_definition_iteration, lang_update_definedness): Declare.
This commit is contained in:
Hans-Peter Nilsson
parent
a8f4cde1ae
commit
420e579cc4
29
ld/ChangeLog
29
ld/ChangeLog
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@ -1,3 +1,32 @@
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2003-10-11 Hans-Peter Nilsson <hp@bitrange.com>
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* ld.texinfo (Builtin Functions) <DEFINED>: Say that only symbols
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defined before the statement using DEFINED yield 1.
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* ldexp.c (fold_name) <case DEFINED>: In lang_first_phase_enum,
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call lang_track_definedness on symbol. In subsequent phases, use
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lang_symbol_definition_iteration and lang_statement_iteration to
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check whether the symbol was defined before the current statement.
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(exp_fold_tree) <case etree_assign et al>: Call
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lang_update_definedness before updating symbol type when setting
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symbol.
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* ldlang.c (lang_definedness_table): New variable.
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(lang_definedness_newfunc, lang_track_definedness)
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(lang_symbol_definition_iteration, lang_update_definedness): New
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functions.
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(lang_init): Initialize lang_definedness_table and
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lang_statement_iteration.
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(lang_finish): Destroy bfd_hash_table_free.
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(lang_size_sections): Increment lang_statement_iteration.
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(lang_do_assignments_1): New function with former
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lang_do_assignments contents. Change recursive calls to call this
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function.
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(lang_do_assignments): Evacuate contents. Increment
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lang_statement_iteration, then just call lang_do_assignments_1.
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* ldlang.h (struct lang_definedness_hash_entry)
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(lang_statement_iteration, lang_track_definedness)
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(lang_symbol_definition_iteration, lang_update_definedness):
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Declare.
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2003-10-09 H.J. Lu <hongjiu.lu@intel.com>
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* scripttempl/elf.sc (__executable_start): Provide.
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@ -4452,7 +4452,8 @@ evaluation purposes.
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@kindex DEFINED(@var{symbol})
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@cindex symbol defaults
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Return 1 if @var{symbol} is in the linker global symbol table and is
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defined, otherwise return 0. You can use this function to provide
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defined before the statement using DEFINED in the script, otherwise
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return 0. You can use this function to provide
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default values for symbols. For example, the following script fragment
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shows how to set a global symbol @samp{begin} to the first location in
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the @samp{.text} section---but if a symbol called @samp{begin} already
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12
ld/ldexp.c
12
ld/ldexp.c
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@ -485,10 +485,15 @@ fold_name (etree_type *tree,
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break;
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case DEFINED:
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if (allocation_done == lang_first_phase_enum)
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result.valid_p = FALSE;
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{
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lang_track_definedness (tree->name.name);
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result.valid_p = FALSE;
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}
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else
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{
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struct bfd_link_hash_entry *h;
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int def_iteration
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= lang_symbol_definition_iteration (tree->name.name);
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h = bfd_wrapped_link_hash_lookup (output_bfd, &link_info,
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tree->name.name,
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@ -496,7 +501,9 @@ fold_name (etree_type *tree,
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result.value = (h != NULL
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&& (h->type == bfd_link_hash_defined
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|| h->type == bfd_link_hash_defweak
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|| h->type == bfd_link_hash_common));
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|| h->type == bfd_link_hash_common)
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&& (def_iteration == lang_statement_iteration
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|| def_iteration == -1));
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result.section = abs_output_section;
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result.valid_p = TRUE;
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}
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@ -738,6 +745,7 @@ exp_fold_tree (etree_type *tree,
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{
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/* FIXME: Should we worry if the symbol is already
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defined? */
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lang_update_definedness (tree->assign.dst, h);
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h->type = bfd_link_hash_defined;
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h->u.def.value = result.value;
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h->u.def.section = result.section->bfd_section;
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143
ld/ldlang.c
143
ld/ldlang.c
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@ -60,6 +60,7 @@ static const char *current_target;
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static const char *output_target;
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static lang_statement_list_type statement_list;
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static struct lang_phdr *lang_phdr_list;
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static struct bfd_hash_table lang_definedness_table;
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/* Forward declarations. */
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static void exp_init_os (etree_type *);
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@ -67,6 +68,8 @@ static bfd_boolean wildcardp (const char *);
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static lang_input_statement_type *lookup_name (const char *);
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static bfd_boolean load_symbols (lang_input_statement_type *,
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lang_statement_list_type *);
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static struct bfd_hash_entry *lang_definedness_newfunc
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(struct bfd_hash_entry *, struct bfd_hash_table *, const char *);
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static void insert_undefined (const char *);
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static void print_statement (lang_statement_union_type *,
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lang_output_section_statement_type *);
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@ -95,6 +98,7 @@ bfd_boolean delete_output_file_on_failure = FALSE;
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struct lang_nocrossrefs *nocrossref_list;
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struct unique_sections *unique_section_list;
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static bfd_boolean ldlang_sysrooted_script = FALSE;
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int lang_statement_iteration = 0;
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etree_type *base; /* Relocation base - or null */
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@ -477,6 +481,19 @@ lang_init (void)
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lang_output_section_statement_lookup (BFD_ABS_SECTION_NAME);
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abs_output_section->bfd_section = bfd_abs_section_ptr;
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/* The value "3" is ad-hoc, somewhat related to the expected number of
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DEFINED expressions in a linker script. For most default linker
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scripts, there are none. Why a hash table then? Well, it's somewhat
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simpler to re-use working machinery than using a linked list in terms
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of code-complexity here in ld, besides the initialization which just
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looks like other code here. */
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if (bfd_hash_table_init_n (&lang_definedness_table,
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lang_definedness_newfunc, 3) != TRUE)
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einfo (_("%P%F: out of memory during initialization"));
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/* Callers of exp_fold_tree need to increment this. */
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lang_statement_iteration = 0;
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}
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/*----------------------------------------------------------------------
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@ -1867,6 +1884,85 @@ lang_reasonable_defaults (void)
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#endif
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}
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/* Add a symbol to a hash of symbols used in DEFINED (NAME) expressions. */
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void
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lang_track_definedness (const char *name)
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{
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if (bfd_hash_lookup (&lang_definedness_table, name, TRUE, FALSE) == NULL)
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einfo (_("%P%F: bfd_hash_lookup failed creating symbol %s\n"), name);
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}
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/* New-function for the definedness hash table. */
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static struct bfd_hash_entry *
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lang_definedness_newfunc (struct bfd_hash_entry *entry,
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struct bfd_hash_table *table ATTRIBUTE_UNUSED,
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const char *name ATTRIBUTE_UNUSED)
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{
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struct lang_definedness_hash_entry *ret
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= (struct lang_definedness_hash_entry *) entry;
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if (ret == NULL)
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ret = (struct lang_definedness_hash_entry *)
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bfd_hash_allocate (table, sizeof (struct lang_definedness_hash_entry));
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if (ret == NULL)
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einfo (_("%P%F: bfd_hash_allocate failed creating symbol %s\n"), name);
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ret->iteration = -1;
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return &ret->root;
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}
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/* Return the iteration when the definition of NAME was last updated. A
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value of -1 means that the symbol is not defined in the linker script
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or the command line, but may be defined in the linker symbol table. */
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int
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lang_symbol_definition_iteration (const char *name)
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{
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struct lang_definedness_hash_entry *defentry
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= (struct lang_definedness_hash_entry *)
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bfd_hash_lookup (&lang_definedness_table, name, FALSE, FALSE);
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/* We've already created this one on the presence of DEFINED in the
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script, so it can't be NULL unless something is borked elsewhere in
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the code. */
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if (defentry == NULL)
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FAIL ();
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return defentry->iteration;
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}
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/* Update the definedness state of NAME. */
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void
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lang_update_definedness (const char *name, struct bfd_link_hash_entry *h)
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{
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struct lang_definedness_hash_entry *defentry
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= (struct lang_definedness_hash_entry *)
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bfd_hash_lookup (&lang_definedness_table, name, FALSE, FALSE);
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/* We don't keep track of symbols not tested with DEFINED. */
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if (defentry == NULL)
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return;
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/* If the symbol was already defined, and not from an earlier statement
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iteration, don't update the definedness iteration, because that'd
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make the symbol seem defined in the linker script at this point, and
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it wasn't; it was defined in some object. If we do anyway, DEFINED
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would start to yield false before this point and the construct "sym =
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DEFINED (sym) ? sym : X;" would change sym to X despite being defined
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in an object. */
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if (h->type != bfd_link_hash_undefined
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&& h->type != bfd_link_hash_common
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&& h->type != bfd_link_hash_new
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&& defentry->iteration == -1)
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return;
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defentry->iteration = lang_statement_iteration;
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}
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/* Add the supplied name to the symbol table as an undefined reference.
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This is a two step process as the symbol table doesn't even exist at
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the time the ld command line is processed. First we put the name
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@ -3132,6 +3228,9 @@ lang_size_sections
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{
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bfd_vma result;
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/* Callers of exp_fold_tree need to increment this. */
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lang_statement_iteration++;
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exp_data_seg.phase = exp_dataseg_none;
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result = lang_size_sections_1 (s, output_section_statement, prev, fill,
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dot, relax, check_regions);
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@ -3157,8 +3256,10 @@ lang_size_sections
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return result;
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}
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bfd_vma
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lang_do_assignments
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/* Worker function for lang_do_assignments. Recursiveness goes here. */
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static bfd_vma
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lang_do_assignments_1
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(lang_statement_union_type *s,
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lang_output_section_statement_type *output_section_statement,
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fill_type *fill,
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@ -3172,10 +3273,10 @@ lang_do_assignments
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switch (s->header.type)
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{
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case lang_constructors_statement_enum:
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dot = lang_do_assignments (constructor_list.head,
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output_section_statement,
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fill,
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dot);
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dot = lang_do_assignments_1 (constructor_list.head,
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output_section_statement,
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fill,
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dot);
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break;
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case lang_output_section_statement_enum:
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@ -3186,8 +3287,8 @@ lang_do_assignments
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if (os->bfd_section != NULL)
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{
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dot = os->bfd_section->vma;
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(void) lang_do_assignments (os->children.head, os,
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os->fill, dot);
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(void) lang_do_assignments_1 (os->children.head, os,
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os->fill, dot);
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dot = os->bfd_section->vma + os->bfd_section->_raw_size / opb;
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}
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@ -3206,9 +3307,9 @@ lang_do_assignments
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break;
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case lang_wild_statement_enum:
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dot = lang_do_assignments (s->wild_statement.children.head,
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output_section_statement,
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fill, dot);
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dot = lang_do_assignments_1 (s->wild_statement.children.head,
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output_section_statement,
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fill, dot);
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break;
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@ -3301,9 +3402,9 @@ lang_do_assignments
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break;
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case lang_group_statement_enum:
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dot = lang_do_assignments (s->group_statement.children.head,
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output_section_statement,
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fill, dot);
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dot = lang_do_assignments_1 (s->group_statement.children.head,
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output_section_statement,
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fill, dot);
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break;
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@ -3318,6 +3419,18 @@ lang_do_assignments
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return dot;
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}
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bfd_vma
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lang_do_assignments (lang_statement_union_type *s,
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lang_output_section_statement_type
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*output_section_statement,
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fill_type *fill,
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bfd_vma dot)
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{
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/* Callers of exp_fold_tree need to increment this. */
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lang_statement_iteration++;
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lang_do_assignments_1 (s, output_section_statement, fill, dot);
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}
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/* Fix any .startof. or .sizeof. symbols. When the assemblers see the
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operator .startof. (section_name), it produces an undefined symbol
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.startof.section_name. Similarly, when it sees
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@ -3445,6 +3558,8 @@ lang_finish (void)
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}
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}
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}
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bfd_hash_table_free (&lang_definedness_table);
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}
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/* This is a small function used when we want to ignore errors from
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14
ld/ldlang.h
14
ld/ldlang.h
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@ -361,6 +361,14 @@ struct unique_sections {
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const char *name;
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};
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/* This structure records symbols for which we need to keep track of
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definedness for use in the DEFINED () test. */
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struct lang_definedness_hash_entry {
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struct bfd_hash_entry root;
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int iteration;
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};
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extern struct unique_sections *unique_section_list;
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extern lang_output_section_statement_type *abs_output_section;
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@ -375,6 +383,8 @@ extern const char *entry_section;
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extern bfd_boolean entry_from_cmdline;
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extern lang_statement_list_type file_chain;
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extern int lang_statement_iteration;
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extern void lang_init
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(void);
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extern struct memory_region_struct *lang_memory_region_lookup
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@ -517,5 +527,9 @@ extern void lang_add_unique
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(const char *);
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extern const char *lang_get_output_target
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(void);
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extern void lang_track_definedness (const char *);
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extern int lang_symbol_definition_iteration (const char *);
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extern void lang_update_definedness
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(const char *, struct bfd_link_hash_entry *);
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#endif
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