X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=ld%2Fldexp.c;h=9f88144b67819df658b5abbcaf3217f28a0f1422;hb=9ad39107ca6e4efcda0f48a6abf528844a2f11aa;hp=34d9eabde7f67506d79f54afdcdc262b194d7b30;hpb=e092cb30d23375162df46825e5b5bc99a339245b;p=deliverable%2Fbinutils-gdb.git diff --git a/ld/ldexp.c b/ld/ldexp.c index 34d9eabde7..9f88144b67 100644 --- a/ld/ldexp.c +++ b/ld/ldexp.c @@ -1,7 +1,5 @@ /* 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 - Free Software Foundation, Inc. + Copyright (C) 1991-2016 Free Software Foundation, Inc. Written by Steve Chamberlain of Cygnus Support . This file is part of the GNU Binutils. @@ -44,13 +42,37 @@ #include "safe-ctype.h" static void exp_fold_tree_1 (etree_type *); -static void exp_fold_tree_no_dot (etree_type *); static bfd_vma align_n (bfd_vma, bfd_vma); segment_type *segments; struct ldexp_control expld; +/* This structure records symbols for which we need to keep track of + definedness for use in the DEFINED () test. It is also used in + making absolute symbols section relative late in the link. */ + +struct definedness_hash_entry +{ + struct bfd_hash_entry root; + + /* If this symbol was assigned from "dot" outside of an output + section statement, the section we'd like it relative to. */ + asection *final_sec; + + /* Symbol was defined by an object file. */ + unsigned int by_object : 1; + + /* Symbols was defined by a script. */ + unsigned int by_script : 1; + + /* Low bit of iteration count. Symbols with matching iteration have + been defined in this pass over the script. */ + unsigned int iteration : 1; +}; + +static struct bfd_hash_table definedness_table; + /* Print the string representation of the given token. Surround it with spaces if INFIX_P is TRUE. */ @@ -60,7 +82,7 @@ exp_print_token (token_code_type code, int infix_p) static const struct { token_code_type code; - char * name; + const char *name; } table[] = { @@ -82,6 +104,7 @@ exp_print_token (token_code_type code, int infix_p) { GE, ">=" }, { LSHIFT, "<<" }, { RSHIFT, ">>" }, + { LOG2CEIL, "LOG2CEIL" }, { ALIGN_K, "ALIGN" }, { BLOCK, "BLOCK" }, { QUAD, "QUAD" }, @@ -135,11 +158,35 @@ exp_print_token (token_code_type code, int infix_p) 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) { - expld.result.value += expld.result.section->vma; + if (expld.result.section != NULL) + expld.result.value += expld.result.section->vma; expld.result.section = bfd_abs_section_ptr; + expld.rel_from_abs = FALSE; } static void @@ -156,6 +203,7 @@ exp_intop (bfd_vma value) { etree_type *new_e = (etree_type *) stat_alloc (sizeof (new_e->value)); new_e->type.node_code = INT; + new_e->type.filename = ldlex_filename (); new_e->type.lineno = lineno; new_e->value.value = value; new_e->value.str = NULL; @@ -168,6 +216,7 @@ exp_bigintop (bfd_vma value, char *str) { etree_type *new_e = (etree_type *) stat_alloc (sizeof (new_e->value)); new_e->type.node_code = INT; + new_e->type.filename = ldlex_filename (); new_e->type.lineno = lineno; new_e->value.value = value; new_e->value.str = str; @@ -182,6 +231,7 @@ exp_relop (asection *section, bfd_vma value) { etree_type *new_e = (etree_type *) stat_alloc (sizeof (new_e->rel)); new_e->type.node_code = REL; + new_e->type.filename = ldlex_filename (); new_e->type.lineno = lineno; new_e->type.node_class = etree_rel; new_e->rel.section = section; @@ -190,21 +240,106 @@ exp_relop (asection *section, bfd_vma value) } static void -new_rel (bfd_vma value, char *str, asection *section) +new_number (bfd_vma value) +{ + expld.result.valid_p = TRUE; + expld.result.value = value; + expld.result.str = NULL; + expld.result.section = NULL; +} + +static void +new_rel (bfd_vma value, asection *section) { expld.result.valid_p = TRUE; expld.result.value = value; - expld.result.str = str; + expld.result.str = NULL; expld.result.section = section; } static void new_rel_from_abs (bfd_vma value) { + asection *s = expld.section; + + expld.rel_from_abs = TRUE; expld.result.valid_p = TRUE; - expld.result.value = value - expld.section->vma; + expld.result.value = value - s->vma; expld.result.str = NULL; - expld.result.section = expld.section; + expld.result.section = s; +} + +/* New-function for the definedness hash table. */ + +static struct bfd_hash_entry * +definedness_newfunc (struct bfd_hash_entry *entry, + struct bfd_hash_table *table ATTRIBUTE_UNUSED, + const char *name ATTRIBUTE_UNUSED) +{ + struct definedness_hash_entry *ret = (struct definedness_hash_entry *) entry; + + if (ret == NULL) + ret = (struct definedness_hash_entry *) + bfd_hash_allocate (table, sizeof (struct definedness_hash_entry)); + + if (ret == NULL) + einfo (_("%P%F: bfd_hash_allocate failed creating symbol %s\n"), name); + + ret->by_object = 0; + ret->by_script = 0; + ret->iteration = 0; + return &ret->root; +} + +/* Called during processing of linker script script expressions. + For symbols assigned in a linker script, return a struct describing + where the symbol is defined relative to the current expression, + otherwise return NULL. */ + +static struct definedness_hash_entry * +symbol_defined (const char *name) +{ + return ((struct definedness_hash_entry *) + bfd_hash_lookup (&definedness_table, name, FALSE, FALSE)); +} + +/* Update the definedness state of NAME. Return FALSE if script symbol + is multiply defining a strong symbol in an object. */ + +static bfd_boolean +update_definedness (const char *name, struct bfd_link_hash_entry *h) +{ + bfd_boolean ret; + struct definedness_hash_entry *defentry + = (struct definedness_hash_entry *) + bfd_hash_lookup (&definedness_table, name, TRUE, FALSE); + + if (defentry == NULL) + einfo (_("%P%F: bfd_hash_lookup failed creating symbol %s\n"), name); + + /* If the symbol was already defined, and not by a script, then it + must be defined by an object file or by the linker target code. */ + ret = TRUE; + if (!defentry->by_script + && (h->type == bfd_link_hash_defined + || h->type == bfd_link_hash_defweak + || h->type == bfd_link_hash_common)) + { + defentry->by_object = 1; + if (h->type == bfd_link_hash_defined + && h->u.def.section->output_section != NULL + && !h->linker_def) + ret = FALSE; + } + + defentry->by_script = 1; + defentry->iteration = lang_statement_iteration; + defentry->final_sec = bfd_abs_section_ptr; + if (expld.phase == lang_final_phase_enum + && expld.rel_from_abs + && expld.result.section == bfd_abs_section_ptr) + defentry->final_sec = section_for_dot (); + return ret; } static void @@ -226,18 +361,19 @@ fold_unary (etree_type *tree) make_abs (); break; + case LOG2CEIL: + make_log2ceil (); + break; + case '~': - make_abs (); expld.result.value = ~expld.result.value; break; case '!': - make_abs (); expld.result.value = !expld.result.value; break; case '-': - make_abs (); expld.result.value = -expld.result.value; break; @@ -253,20 +389,22 @@ fold_unary (etree_type *tree) 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; @@ -293,16 +431,21 @@ fold_binary (etree_type *tree) { const char *segment_name; segment_type *seg; + /* 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 + && config.magic_demand_paged + && (seg->value % config.maxpagesize) != 0) + einfo (_("%P: warning: address of `%s' " + "isn't multiple of maximum page size\n"), + segment_name); seg->used = TRUE; - expld.result.value = seg->value; - expld.result.str = NULL; - expld.result.section = expld.section; + new_rel_from_abs (seg->value); break; } return; @@ -314,42 +457,87 @@ fold_binary (etree_type *tree) if (expld.result.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 (expld.section != bfd_abs_section_ptr - && lhs.section == bfd_abs_section_ptr - && tree->type.node_code == '+') - { - /* Keep the section of the rhs term. */ - expld.result.value = lhs.value + expld.result.value; - return; - } - else if (expld.section != bfd_abs_section_ptr - && expld.result.section == bfd_abs_section_ptr - && (tree->type.node_code == '+' - || tree->type.node_code == '-')) + if (lhs.section != expld.result.section) { - /* Keep the section of the lhs term. */ - expld.result.section = lhs.section; - } - else if (expld.result.section != lhs.section - || expld.section == bfd_abs_section_ptr) - { - make_abs (); - lhs.value += lhs.section->vma; + /* If the values are from different sections, and neither is + just a number, make both the source arguments absolute. */ + if (expld.result.section != NULL + && lhs.section != NULL) + { + 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; + /* 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) { + /* 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; \ + expld.result.section = NULL; \ + break; + + BOP ('+', +); + BOP ('*', *); + BOP ('-', -); + BOP (LSHIFT, <<); + BOP (RSHIFT, >>); + BOP ('&', &); + BOP ('^', ^); + BOP ('|', |); + BOPN (EQ, ==); + BOPN (NE, !=); + BOPN ('<', <); + BOPN ('>', >); + BOPN (LE, <=); + BOPN (GE, >=); + 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")); + einfo (_("%F%S %% by zero\n"), tree->binary.rhs); + if (expld.result.section == lhs.section) + expld.result.section = NULL; break; case '/': @@ -357,31 +545,11 @@ fold_binary (etree_type *tree) 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")); + einfo (_("%F%S / by zero\n"), tree->binary.rhs); + if (expld.result.section == lhs.section) + expld.result.section = NULL; break; -#define BOP(x, y) \ - case x: \ - expld.result.value = lhs.value y expld.result.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 (lhs.value > expld.result.value) expld.result.value = lhs.value; @@ -398,12 +566,10 @@ fold_binary (etree_type *tree) 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; @@ -411,34 +577,45 @@ fold_binary (etree_type *tree) 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.base = expld.result.value; expld.dataseg.pagesize = commonpage; 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: + /* Operands swapped! DATA_SEGMENT_RELRO_END(offset,exp) + has offset in expld.result and exp in lhs. */ 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)) + expld.dataseg.relro_offset = expld.result.value; + 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) @@ -494,35 +671,51 @@ fold_name (etree_type *tree) The bfd function may cache incorrect data. */ if (expld.phase != lang_mark_phase_enum) hdr_size = bfd_sizeof_headers (link_info.output_bfd, &link_info); - new_abs (hdr_size); + new_number (hdr_size); } 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 definedness_hash_entry *def; h = bfd_wrapped_link_hash_lookup (link_info.output_bfd, &link_info, tree->name.name, FALSE, FALSE, TRUE); - expld.result.value = (h != NULL - && (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)); - expld.result.section = expld.section; - expld.result.valid_p = TRUE; + new_number (h != NULL + && (h->type == bfd_link_hash_defined + || h->type == bfd_link_hash_defweak + || h->type == bfd_link_hash_common) + && ((def = 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 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 = 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) @@ -540,29 +733,32 @@ fold_name (etree_type *tree) else if (h->type == bfd_link_hash_defined || h->type == bfd_link_hash_defweak) { - if (bfd_is_abs_section (h->u.def.section)) - new_abs (h->u.def.value); - else - { - asection *output_section; + asection *output_section; - output_section = h->u.def.section->output_section; - if (output_section == NULL) - { - if (expld.phase != lang_mark_phase_enum) - einfo (_("%X%S: unresolvable symbol `%s'" - " referenced in expression\n"), - tree->name.name); - } + output_section = h->u.def.section->output_section; + if (output_section == NULL) + { + if (expld.phase == lang_mark_phase_enum) + new_rel (h->u.def.value, h->u.def.section); else - new_rel (h->u.def.value + h->u.def.section->output_offset, - NULL, output_section); + einfo (_("%X%S: unresolvable symbol `%s'" + " referenced in expression\n"), + tree, tree->name.name); } + 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, + output_section); } else if (expld.phase == lang_final_phase_enum - || expld.assigning_to_dot) - einfo (_("%F%S: undefined symbol `%s' referenced in expression\n"), - tree->name.name); + || (expld.phase != lang_mark_phase_enum + && expld.assigning_to_dot)) + einfo (_("%F%S: undefined symbol `%s'" + " referenced in expression\n"), + tree, tree->name.name); else if (h->type == bfd_link_hash_new) { h->type = bfd_link_hash_undefined; @@ -582,11 +778,12 @@ fold_name (etree_type *tree) if (os == NULL) { if (expld.phase == lang_final_phase_enum) - einfo (_("%F%S: undefined section `%s' referenced in expression\n"), - tree->name.name); + einfo (_("%F%S: undefined section `%s'" + " referenced in expression\n"), + tree, tree->name.name); } else if (os->processed_vma) - new_rel (0, NULL, os->bfd_section); + new_rel (0, os->bfd_section); } break; @@ -599,8 +796,9 @@ fold_name (etree_type *tree) if (os == NULL) { if (expld.phase == lang_final_phase_enum) - einfo (_("%F%S: undefined section `%s' referenced in expression\n"), - tree->name.name); + einfo (_("%F%S: undefined section `%s'" + " referenced in expression\n"), + tree, tree->name.name); } else if (os->processed_lma) { @@ -626,11 +824,12 @@ fold_name (etree_type *tree) if (os == NULL) { if (expld.phase == lang_final_phase_enum) - einfo (_("%F%S: undefined section `%s' referenced in expression\n"), - tree->name.name); - new_abs (0); + einfo (_("%F%S: undefined section `%s'" + " referenced in expression\n"), + tree, tree->name.name); + new_number (0); } - else if (os->processed_vma) + else if (os->bfd_section != NULL) { bfd_vma val; @@ -639,46 +838,54 @@ fold_name (etree_type *tree) / bfd_octets_per_byte (link_info.output_bfd)); else val = (bfd_vma)1 << os->bfd_section->alignment_power; - - new_abs (val); + + new_number (val); } + else + new_number (0); } break; case LENGTH: { - lang_memory_region_type *mem; - - mem = lang_memory_region_lookup (tree->name.name, FALSE); - if (mem != NULL) - new_abs (mem->length); - else - einfo (_("%F%S: undefined MEMORY region `%s'" - " referenced in expression\n"), 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) + new_number (mem->length); + else + einfo (_("%F%S: undefined MEMORY region `%s'" + " referenced in expression\n"), + tree, tree->name.name); + } } break; case ORIGIN: - { - lang_memory_region_type *mem; - - mem = lang_memory_region_lookup (tree->name.name, FALSE); - if (mem != NULL) - new_abs (mem->origin); - else - einfo (_("%F%S: undefined MEMORY region `%s'" - " referenced in expression\n"), 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) + new_rel_from_abs (mem->origin); + else + einfo (_("%F%S: undefined MEMORY region `%s'" + " referenced in expression\n"), + tree, tree->name.name); + } break; case CONSTANT: if (strcmp (tree->name.name, "MAXPAGESIZE") == 0) - new_abs (config.maxpagesize); + new_number (config.maxpagesize); else if (strcmp (tree->name.name, "COMMONPAGESIZE") == 0) - new_abs (config.commonpagesize); + new_number (config.commonpagesize); else einfo (_("%F%S: unknown constant `%s' referenced in expression\n"), - tree->name.name); + tree, tree->name.name); break; default: @@ -687,6 +894,106 @@ fold_name (etree_type *tree) } } +/* 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 definedness_hash_entry *def; + + return (tree->type.node_class == etree_name + && tree->type.node_code == NAME + && (def = 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 FALSE; +} + +/* Subroutine of exp_fold_tree_1 for copying a symbol type. */ + +static void +try_copy_symbol_type (struct bfd_link_hash_entry *h, etree_type *src) +{ + if (src->type.node_class == etree_name) + { + struct bfd_link_hash_entry *hsrc; + + hsrc = bfd_link_hash_lookup (link_info.hash, src->name.name, + FALSE, FALSE, TRUE); + if (hsrc) + bfd_copy_link_hash_symbol_type (link_info.output_bfd, h, + hsrc); + } +} + static void exp_fold_tree_1 (etree_type *tree) { @@ -699,7 +1006,12 @@ exp_fold_tree_1 (etree_type *tree) switch (tree->type.node_class) { case etree_value: - new_rel (tree->value.value, tree->value.str, expld.section); + 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_rel: @@ -707,7 +1019,7 @@ exp_fold_tree_1 (etree_type *tree) { asection *output_section = tree->rel.section->output_section; new_rel (tree->rel.value + tree->rel.section->output_offset, - NULL, output_section); + output_section); } else memset (&expld.result, 0, sizeof (expld.result)); @@ -736,36 +1048,64 @@ exp_fold_tree_1 (etree_type *tree) 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 (expld.phase == lang_mark_phase_enum - || expld.phase == lang_allocating_phase_enum - || (expld.phase == lang_final_phase_enum - && expld.section == bfd_abs_section_ptr)) + einfo (_("%F%S can not PROVIDE assignment to" + " location counter\n"), tree); + if (expld.phase != lang_first_phase_enum) { /* Notify the folder that this is an assignment to dot. */ expld.assigning_to_dot = TRUE; 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). + We can't ignore all expressions that evaluate to zero + because an otherwise empty section might have padding + added by an alignment expression that changes with + relaxation. Such a section might have zero size + before relaxation and so be stripped incorrectly. */ + 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) - einfo (_("%F%S invalid assignment to location counter\n")); + einfo (_("%F%S invalid assignment to" + " location counter\n"), tree); } else if (expld.dotp == NULL) einfo (_("%F%S assignment to location counter" - " invalid outside of SECTION\n")); - else + " invalid outside of SECTIONS\n"), tree); + + /* After allocation, assignment to dot should not be + done inside an output section since allocation adds a + padding statement that effectively duplicates the + assignment. */ + else if (expld.phase <= lang_allocating_phase_enum + || expld.section == bfd_abs_section_ptr) { bfd_vma nextdot; - nextdot = expld.result.value + expld.section->vma; + nextdot = expld.result.value; + if (expld.result.section != NULL) + nextdot += expld.result.section->vma; + else + nextdot += expld.section->vma; if (nextdot < expld.dot && expld.section != bfd_abs_section_ptr) einfo (_("%F%S cannot move location counter backwards" - " (from %V to %V)\n"), expld.dot, nextdot); + " (from %V to %V)\n"), + tree, expld.dot, nextdot); else { expld.dot = nextdot; @@ -785,18 +1125,37 @@ exp_fold_tree_1 (etree_type *tree) h = bfd_link_hash_lookup (link_info.hash, tree->assign.dst, FALSE, FALSE, TRUE); 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_new + || h->type == bfd_link_hash_undefined + || h->type == bfd_link_hash_undefweak + || h->linker_def)) { - /* Do nothing. The symbol was never referenced, or was - defined by some object. */ + /* Do nothing. The symbol was never referenced, or + was defined in some object file. Note that + undefweak symbols are defined by PROVIDE. This + is to support glibc use of __rela_iplt_start and + similar weak references. */ 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.defsym)) { if (h == NULL) { @@ -807,27 +1166,47 @@ exp_fold_tree_1 (etree_type *tree) tree->assign.dst); } - /* FIXME: Should we worry if the symbol is already - defined? */ - lang_update_definedness (tree->assign.dst, h); + if (expld.result.section == NULL) + expld.result.section = expld.section; + if (!update_definedness (tree->assign.dst, h) && 0) + { + /* Symbol was already defined. For now this error + is disabled because it causes failures in the ld + testsuite: ld-elf/var1, ld-scripts/defined5, and + ld-scripts/pr14962. Some of these no doubt + reflect scripts used in the wild. */ + (*link_info.callbacks->multiple_definition) + (&link_info, h, link_info.output_bfd, + expld.result.section, expld.result.value); + } h->type = bfd_link_hash_defined; h->u.def.value = expld.result.value; h->u.def.section = expld.result.section; + h->linker_def = ! tree->assign.type.lineno; + h->ldscript_def = 1; if (tree->type.node_class == etree_provide) 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. Also, handle the case of a foldable + ternary conditional with names on either side. */ if (tree->assign.src->type.node_class == etree_name) + try_copy_symbol_type (h, tree->assign.src); + else if (tree->assign.src->type.node_class == etree_trinary) { - struct bfd_link_hash_entry *hsrc; - - hsrc = bfd_link_hash_lookup (link_info.hash, - tree->assign.src->name.name, - FALSE, FALSE, TRUE); - if (hsrc) - bfd_copy_link_hash_symbol_type (link_info.output_bfd, h, - hsrc); + exp_fold_tree_1 (tree->assign.src->trinary.cond); + if (expld.result.valid_p) + { + if (expld.result.value + && tree->assign.src->trinary.lhs->type.node_class + == etree_name) + try_copy_symbol_type (h, tree->assign.src->trinary.lhs); + + if (!expld.result.value + && tree->assign.src->trinary.rhs->type.node_class + == etree_name) + try_copy_symbol_type (h, tree->assign.src->trinary.rhs); + } } } else if (expld.phase == lang_final_phase_enum) @@ -838,6 +1217,7 @@ exp_fold_tree_1 (etree_type *tree) && h->type == bfd_link_hash_new) h->type = bfd_link_hash_undefined; } + expld.assign_name = NULL; } break; @@ -855,110 +1235,143 @@ exp_fold_tree_1 (etree_type *tree) void exp_fold_tree (etree_type *tree, asection *current_section, bfd_vma *dotp) { + expld.rel_from_abs = FALSE; expld.dot = *dotp; expld.dotp = dotp; expld.section = current_section; exp_fold_tree_1 (tree); } -static void +void exp_fold_tree_no_dot (etree_type *tree) { + expld.rel_from_abs = FALSE; expld.dot = 0; expld.dotp = NULL; expld.section = bfd_abs_section_ptr; exp_fold_tree_1 (tree); } +static void +exp_value_fold (etree_type *tree) +{ + exp_fold_tree_no_dot (tree); + if (expld.result.valid_p) + { + tree->type.node_code = INT; + tree->value.value = expld.result.value; + tree->value.str = NULL; + tree->type.node_class = etree_value; + } +} + etree_type * exp_binop (int code, etree_type *lhs, etree_type *rhs) { - etree_type value, *new_e; - - value.type.node_code = code; - value.type.lineno = lhs->type.lineno; - value.binary.lhs = lhs; - value.binary.rhs = rhs; - value.type.node_class = etree_binary; - exp_fold_tree_no_dot (&value); - if (expld.result.valid_p) - return exp_intop (expld.result.value); + etree_type *new_e = (etree_type *) stat_alloc (sizeof (new_e->binary)); - new_e = (etree_type *) stat_alloc (sizeof (new_e->binary)); - memcpy (new_e, &value, sizeof (new_e->binary)); + new_e->type.node_code = code; + new_e->type.filename = lhs->type.filename; + new_e->type.lineno = lhs->type.lineno; + new_e->binary.lhs = lhs; + new_e->binary.rhs = rhs; + new_e->type.node_class = etree_binary; + if (lhs->type.node_class == etree_value + && rhs->type.node_class == etree_value + && code != ALIGN_K + && code != DATA_SEGMENT_ALIGN + && code != DATA_SEGMENT_RELRO_END) + exp_value_fold (new_e); return new_e; } etree_type * exp_trinop (int code, etree_type *cond, etree_type *lhs, etree_type *rhs) { - etree_type value, *new_e; - - value.type.node_code = code; - value.type.lineno = lhs->type.lineno; - value.trinary.lhs = lhs; - value.trinary.cond = cond; - value.trinary.rhs = rhs; - value.type.node_class = etree_trinary; - exp_fold_tree_no_dot (&value); - if (expld.result.valid_p) - return exp_intop (expld.result.value); + etree_type *new_e = (etree_type *) stat_alloc (sizeof (new_e->trinary)); - new_e = (etree_type *) stat_alloc (sizeof (new_e->trinary)); - memcpy (new_e, &value, sizeof (new_e->trinary)); + new_e->type.node_code = code; + new_e->type.filename = cond->type.filename; + new_e->type.lineno = cond->type.lineno; + new_e->trinary.lhs = lhs; + new_e->trinary.cond = cond; + new_e->trinary.rhs = rhs; + new_e->type.node_class = etree_trinary; + if (cond->type.node_class == etree_value + && lhs->type.node_class == etree_value + && rhs->type.node_class == etree_value) + exp_value_fold (new_e); return new_e; } etree_type * exp_unop (int code, etree_type *child) { - etree_type value, *new_e; - - value.unary.type.node_code = code; - value.unary.type.lineno = child->type.lineno; - value.unary.child = child; - value.unary.type.node_class = etree_unary; - exp_fold_tree_no_dot (&value); - if (expld.result.valid_p) - return exp_intop (expld.result.value); - - new_e = (etree_type *) stat_alloc (sizeof (new_e->unary)); - memcpy (new_e, &value, sizeof (new_e->unary)); + etree_type *new_e = (etree_type *) stat_alloc (sizeof (new_e->unary)); + + new_e->unary.type.node_code = code; + new_e->unary.type.filename = child->type.filename; + new_e->unary.type.lineno = child->type.lineno; + new_e->unary.child = child; + new_e->unary.type.node_class = etree_unary; + if (child->type.node_class == etree_value + && code != ALIGN_K + && code != ABSOLUTE + && code != NEXT + && code != DATA_SEGMENT_END) + exp_value_fold (new_e); return new_e; } etree_type * exp_nameop (int code, const char *name) { - etree_type value, *new_e; + etree_type *new_e = (etree_type *) stat_alloc (sizeof (new_e->name)); - value.name.type.node_code = code; - value.name.type.lineno = lineno; - value.name.name = name; - value.name.type.node_class = etree_name; + new_e->name.type.node_code = code; + new_e->name.type.filename = ldlex_filename (); + new_e->name.type.lineno = lineno; + new_e->name.name = name; + new_e->name.type.node_class = etree_name; + return new_e; - exp_fold_tree_no_dot (&value); - if (expld.result.valid_p) - return exp_intop (expld.result.value); +} - new_e = (etree_type *) stat_alloc (sizeof (new_e->name)); - memcpy (new_e, &value, sizeof (new_e->name)); - return new_e; +static etree_type * +exp_assop (const char *dst, + etree_type *src, + enum node_tree_enum class, + bfd_boolean defsym, + bfd_boolean hidden) +{ + etree_type *n; + n = (etree_type *) stat_alloc (sizeof (n->assign)); + n->assign.type.node_code = '='; + n->assign.type.filename = src->type.filename; + n->assign.type.lineno = src->type.lineno; + 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_assop (int code, const char *dst, etree_type *src) +exp_assign (const char *dst, etree_type *src, bfd_boolean hidden) { - etree_type *new_e; + return exp_assop (dst, src, etree_assign, FALSE, hidden); +} - 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 --defsym command-line option. */ + +etree_type * +exp_defsym (const char *dst, etree_type *src) +{ + return exp_assop (dst, src, etree_assign, TRUE, FALSE); } /* Handle PROVIDE. */ @@ -966,16 +1379,7 @@ exp_assop (int code, const char *dst, etree_type *src) etree_type * exp_provide (const char *dst, etree_type *src, 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.src = src; - n->assign.dst = dst; - n->assign.hidden = hidden; - return n; + return exp_assop (dst, src, etree_provide, FALSE, hidden); } /* Handle ASSERT. */ @@ -987,6 +1391,7 @@ exp_assert (etree_type *exp, const char *message) n = (etree_type *) stat_alloc (sizeof (n->assert_s)); n->assert_s.type.node_code = '!'; + n->assert_s.type.filename = exp->type.filename; n->assert_s.type.lineno = exp->type.lineno; n->assert_s.type.node_class = etree_assert; n->assert_s.child = exp; @@ -997,6 +1402,8 @@ exp_assert (etree_type *exp, const char *message) void exp_print_tree (etree_type *tree) { + bfd_boolean function_like; + if (config.map_file == NULL) config.map_file = stderr; @@ -1017,7 +1424,7 @@ exp_print_tree (etree_type *tree) minfo ("%s+0x%v", tree->rel.section->name, tree->rel.value); return; case etree_assign: - fprintf (config.map_file, "%s", tree->assign.dst); + fputs (tree->assign.dst, config.map_file); exp_print_token (tree->type.node_code, TRUE); exp_print_tree (tree->assign.src); break; @@ -1025,20 +1432,49 @@ exp_print_tree (etree_type *tree) case etree_provided: fprintf (config.map_file, "PROVIDE (%s, ", tree->assign.dst); exp_print_tree (tree->assign.src); - fprintf (config.map_file, ")"); + fputc (')', config.map_file); break; case etree_binary: - fprintf (config.map_file, "("); + function_like = FALSE; + switch (tree->type.node_code) + { + case MAX_K: + case MIN_K: + case ALIGN_K: + case DATA_SEGMENT_ALIGN: + case DATA_SEGMENT_RELRO_END: + function_like = TRUE; + break; + case SEGMENT_START: + /* Special handling because arguments are in reverse order and + the segment name is quoted. */ + exp_print_token (tree->type.node_code, FALSE); + fputs (" (\"", config.map_file); + exp_print_tree (tree->binary.rhs); + fputs ("\", ", config.map_file); + exp_print_tree (tree->binary.lhs); + fputc (')', config.map_file); + return; + } + if (function_like) + { + exp_print_token (tree->type.node_code, FALSE); + fputc (' ', config.map_file); + } + fputc ('(', config.map_file); exp_print_tree (tree->binary.lhs); - exp_print_token (tree->type.node_code, TRUE); + if (function_like) + fprintf (config.map_file, ", "); + else + exp_print_token (tree->type.node_code, TRUE); exp_print_tree (tree->binary.rhs); - fprintf (config.map_file, ")"); + fputc (')', config.map_file); break; case etree_trinary: exp_print_tree (tree->trinary.cond); - fprintf (config.map_file, "?"); + fputc ('?', config.map_file); exp_print_tree (tree->trinary.lhs); - fprintf (config.map_file, ":"); + fputc (':', config.map_file); exp_print_tree (tree->trinary.rhs); break; case etree_unary: @@ -1047,7 +1483,7 @@ exp_print_tree (etree_type *tree) { fprintf (config.map_file, " ("); exp_print_tree (tree->unary.child); - fprintf (config.map_file, ")"); + fputc (')', config.map_file); } break; @@ -1059,9 +1495,7 @@ exp_print_tree (etree_type *tree) case etree_name: if (tree->type.node_code == NAME) - { - fprintf (config.map_file, "%s", tree->name.name); - } + fputs (tree->name.name, config.map_file); else { exp_print_token (tree->type.node_code, FALSE); @@ -1084,7 +1518,8 @@ exp_get_vma (etree_type *tree, bfd_vma def, char *name) if (expld.result.valid_p) return expld.result.value; else if (name != NULL && expld.phase != lang_mark_phase_enum) - einfo (_("%F%S: nonconstant expression for %s\n"), name); + einfo (_("%F%S: nonconstant expression for %s\n"), + tree, name); } return def; } @@ -1109,7 +1544,8 @@ exp_get_fill (etree_type *tree, fill_type *def, char *name) if (!expld.result.valid_p) { if (name != NULL && expld.phase != lang_mark_phase_enum) - einfo (_("%F%S: nonconstant expression for %s\n"), name); + einfo (_("%F%S: nonconstant expression for %s\n"), + tree, name); return def; } @@ -1162,13 +1598,14 @@ exp_get_abs_int (etree_type *tree, int def, char *name) if (expld.result.valid_p) { - expld.result.value += expld.result.section->vma; + if (expld.result.section != NULL) + expld.result.value += expld.result.section->vma; return expld.result.value; } else if (name != NULL && expld.phase != lang_mark_phase_enum) { - lineno = tree->type.lineno; - einfo (_("%F%S: nonconstant expression for %s\n"), name); + einfo (_("%F%S: nonconstant expression for %s\n"), + tree, name); } } return def; @@ -1183,3 +1620,51 @@ align_n (bfd_vma value, bfd_vma align) value = (value + align - 1) / align; return value * align; } + +void +ldexp_init (void) +{ + /* The value "13" is ad-hoc, somewhat related to the expected number of + assignments in a linker script. */ + if (!bfd_hash_table_init_n (&definedness_table, + definedness_newfunc, + sizeof (struct definedness_hash_entry), + 13)) + einfo (_("%P%F: can not create hash table: %E\n")); +} + +/* Convert absolute symbols defined by a script from "dot" (also + SEGMENT_START or ORIGIN) outside of an output section statement, + to section relative. */ + +static bfd_boolean +set_sym_sections (struct bfd_hash_entry *bh, void *inf ATTRIBUTE_UNUSED) +{ + struct definedness_hash_entry *def = (struct definedness_hash_entry *) bh; + if (def->final_sec != bfd_abs_section_ptr) + { + struct bfd_link_hash_entry *h; + h = bfd_link_hash_lookup (link_info.hash, bh->string, + FALSE, FALSE, TRUE); + if (h != NULL + && h->type == bfd_link_hash_defined + && h->u.def.section == bfd_abs_section_ptr) + { + h->u.def.value -= def->final_sec->vma; + h->u.def.section = def->final_sec; + } + } + return TRUE; +} + +void +ldexp_finalize_syms (void) +{ + bfd_hash_traverse (&definedness_table, set_sym_sections, NULL); +} + +void +ldexp_finish (void) +{ + bfd_hash_table_free (&definedness_table); +}