/* This module handles expression trees. Copyright (C) 1991, 92, 93, 94, 95, 96, 97, 98, 99, 2000 Free Software Foundation, Inc. Written by Steve Chamberlain of Cygnus Support . This file is part of GLD, the Gnu Linker. GLD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GLD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GLD; see the file COPYING. If not, write to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /* This module is in charge of working out the contents of expressions. It has to keep track of the relative/absness of a symbol etc. This is done by keeping all values in a struct (an etree_value_type) which contains a value, a section to which it is relative and a valid bit. */ #include "bfd.h" #include "sysdep.h" #include "bfdlink.h" #include "ld.h" #include "ldmain.h" #include "ldmisc.h" #include "ldexp.h" #include "ldgram.h" #include "ldlang.h" static void exp_print_token PARAMS ((token_code_type code)); static void make_abs PARAMS ((etree_value_type *ptr)); static etree_value_type new_abs PARAMS ((bfd_vma value)); static void check PARAMS ((lang_output_section_statement_type *os, const char *name, const char *op)); static etree_value_type new_rel PARAMS ((bfd_vma value, lang_output_section_statement_type *section)); static etree_value_type new_rel_from_section PARAMS ((bfd_vma value, lang_output_section_statement_type *section)); static etree_value_type fold_binary PARAMS ((etree_type *tree, lang_output_section_statement_type *current_section, lang_phase_type allocation_done, bfd_vma dot, bfd_vma *dotp)); static etree_value_type fold_name PARAMS ((etree_type *tree, lang_output_section_statement_type *current_section, lang_phase_type allocation_done, bfd_vma dot)); static etree_value_type exp_fold_tree_no_dot PARAMS ((etree_type *tree, lang_output_section_statement_type *current_section, lang_phase_type allocation_done)); static void exp_print_token (code) token_code_type code; { static CONST struct { token_code_type code; char *name; } table[] = { { INT, "int" }, { REL, "relocateable" }, { NAME, "NAME" }, { PLUSEQ, "+=" }, { MINUSEQ, "-=" }, { MULTEQ, "*=" }, { DIVEQ, "/=" }, { LSHIFTEQ, "<<=" }, { RSHIFTEQ, ">>=" }, { ANDEQ, "&=" }, { OREQ, "|=" }, { OROR, "||" }, { ANDAND, "&&" }, { EQ, "==" }, { NE, "!=" }, { LE, "<=" }, { GE, ">=" }, { LSHIFT, "<<" }, { RSHIFT, ">>=" }, { ALIGN_K, "ALIGN" }, { BLOCK, "BLOCK" }, { SECTIONS, "SECTIONS" }, { SIZEOF_HEADERS, "SIZEOF_HEADERS" }, { NEXT, "NEXT" }, { SIZEOF, "SIZEOF" }, { ADDR, "ADDR" }, { LOADADDR, "LOADADDR" }, { MEMORY, "MEMORY" }, { DEFINED, "DEFINED" }, { TARGET_K, "TARGET" }, { SEARCH_DIR, "SEARCH_DIR" }, { MAP, "MAP" }, { QUAD, "QUAD" }, { SQUAD, "SQUAD" }, { LONG, "LONG" }, { SHORT, "SHORT" }, { BYTE, "BYTE" }, { ENTRY, "ENTRY" }, { 0, (char *) NULL } }; unsigned int idx; for (idx = 0; table[idx].name != (char *) NULL; idx++) { if (table[idx].code == code) { fprintf (config.map_file, "%s", table[idx].name); return; } } /* Not in table, just print it alone */ fprintf (config.map_file, "%c", code); } static void make_abs (ptr) etree_value_type *ptr; { asection *s = ptr->section->bfd_section; ptr->value += s->vma; ptr->section = abs_output_section; } static etree_value_type new_abs (value) bfd_vma value; { etree_value_type new; new.valid_p = true; new.section = abs_output_section; new.value = value; return new; } static void check (os, name, op) lang_output_section_statement_type *os; const char *name; const char *op; { if (os == NULL) einfo (_("%F%P: %s uses undefined section %s\n"), op, name); if (! os->processed) einfo (_("%F%P: %s forward reference of section %s\n"), op, name); } etree_type * exp_intop (value) bfd_vma value; { etree_type *new = (etree_type *) stat_alloc (sizeof (new->value)); new->type.node_code = INT; new->value.value = value; new->type.node_class = etree_value; return new; } /* Build an expression representing an unnamed relocateable value. */ etree_type * exp_relop (section, value) asection *section; bfd_vma value; { etree_type *new = (etree_type *) stat_alloc (sizeof (new->rel)); new->type.node_code = REL; new->type.node_class = etree_rel; new->rel.section = section; new->rel.value = value; return new; } static etree_value_type new_rel (value, section) bfd_vma value; lang_output_section_statement_type *section; { etree_value_type new; new.valid_p = true; new.value = value; new.section = section; return new; } static etree_value_type new_rel_from_section (value, section) bfd_vma value; lang_output_section_statement_type *section; { etree_value_type new; new.valid_p = true; new.value = value; new.section = section; new.value -= section->bfd_section->vma; return new; } static etree_value_type fold_binary (tree, current_section, allocation_done, dot, dotp) etree_type *tree; lang_output_section_statement_type *current_section; lang_phase_type allocation_done; bfd_vma dot; bfd_vma *dotp; { etree_value_type result; result = exp_fold_tree (tree->binary.lhs, current_section, allocation_done, dot, dotp); if (result.valid_p) { etree_value_type other; other = exp_fold_tree (tree->binary.rhs, current_section, allocation_done, dot, dotp); if (other.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 (current_section != abs_output_section && (other.section == abs_output_section || (result.section == abs_output_section && tree->type.node_code == '+')) && (tree->type.node_code == '+' || tree->type.node_code == '-')) { etree_value_type hold; /* If there is only one absolute term, make sure it is the second one. */ if (other.section != abs_output_section) { hold = result; result = other; other = hold; } } else if (result.section != other.section || current_section == abs_output_section) { make_abs (&result); make_abs (&other); } switch (tree->type.node_code) { case '%': if (other.value == 0) einfo (_("%F%S %% by zero\n")); result.value = ((bfd_signed_vma) result.value % (bfd_signed_vma) other.value); break; case '/': if (other.value == 0) einfo (_("%F%S / by zero\n")); result.value = ((bfd_signed_vma) result.value / (bfd_signed_vma) other.value); break; #define BOP(x,y) case x : result.value = result.value y other.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 (result.value < other.value) result = other; break; case MIN_K: if (result.value > other.value) result = other; break; default: FAIL (); } } else { result.valid_p = false; } } return result; } etree_value_type invalid () { etree_value_type new; new.valid_p = false; return new; } static etree_value_type fold_name (tree, current_section, allocation_done, dot) etree_type *tree; lang_output_section_statement_type *current_section; lang_phase_type allocation_done; bfd_vma dot; { etree_value_type result; switch (tree->type.node_code) { case SIZEOF_HEADERS: if (allocation_done != lang_first_phase_enum) { result = new_abs ((bfd_vma) bfd_sizeof_headers (output_bfd, link_info.relocateable)); } else { result.valid_p = false; } break; case DEFINED: if (allocation_done == lang_first_phase_enum) result.valid_p = false; else { struct bfd_link_hash_entry *h; h = bfd_wrapped_link_hash_lookup (output_bfd, &link_info, tree->name.name, false, false, true); result.value = (h != (struct bfd_link_hash_entry *) NULL && (h->type == bfd_link_hash_defined || h->type == bfd_link_hash_defweak || h->type == bfd_link_hash_common)); result.section = 0; result.valid_p = true; } break; case NAME: result.valid_p = false; if (tree->name.name[0] == '.' && tree->name.name[1] == 0) { if (allocation_done != lang_first_phase_enum) result = new_rel_from_section (dot, current_section); else result = invalid (); } else if (allocation_done != lang_first_phase_enum) { struct bfd_link_hash_entry *h; h = bfd_wrapped_link_hash_lookup (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)) { if (bfd_is_abs_section (h->u.def.section)) result = new_abs (h->u.def.value); else if (allocation_done == lang_final_phase_enum || allocation_done == lang_allocating_phase_enum) { asection *output_section; output_section = h->u.def.section->output_section; if (output_section == NULL) einfo (_("%X%S: unresolvable symbol `%s' referenced in expression\n"), tree->name.name); else { lang_output_section_statement_type *os; os = (lang_output_section_statement_lookup (bfd_get_section_name (output_bfd, output_section))); /* FIXME: Is this correct if this section is being linked with -R? */ result = new_rel ((h->u.def.value + h->u.def.section->output_offset), os); } } } else if (allocation_done == lang_final_phase_enum) einfo (_("%F%S: undefined symbol `%s' referenced in expression\n"), tree->name.name); } break; case ADDR: if (allocation_done != lang_first_phase_enum) { lang_output_section_statement_type *os; os = lang_output_section_find (tree->name.name); check (os, tree->name.name, "ADDR"); result = new_rel (0, os); } else result = invalid (); break; case LOADADDR: if (allocation_done != lang_first_phase_enum) { lang_output_section_statement_type *os; os = lang_output_section_find (tree->name.name); check (os, tree->name.name, "LOADADDR"); if (os->load_base == NULL) result = new_rel (0, os); else result = exp_fold_tree_no_dot (os->load_base, abs_output_section, allocation_done); } else result = invalid (); break; case SIZEOF: if (allocation_done != lang_first_phase_enum) { int opb = bfd_octets_per_byte (output_bfd); lang_output_section_statement_type *os; os = lang_output_section_find (tree->name.name); check (os, tree->name.name, "SIZEOF"); result = new_abs (os->bfd_section->_raw_size / opb); } else result = invalid (); break; default: FAIL (); break; } return result; } etree_value_type exp_fold_tree (tree, current_section, allocation_done, dot, dotp) etree_type *tree; lang_output_section_statement_type *current_section; lang_phase_type allocation_done; bfd_vma dot; bfd_vma *dotp; { etree_value_type result; if (tree == NULL) { result.valid_p = false; return result; } switch (tree->type.node_class) { case etree_value: result = new_rel (tree->value.value, current_section); break; case etree_rel: if (allocation_done != lang_final_phase_enum) result.valid_p = false; else result = new_rel ((tree->rel.value + tree->rel.section->output_section->vma + tree->rel.section->output_offset), current_section); break; case etree_assert: result = exp_fold_tree (tree->assert_s.child, current_section, allocation_done, dot, dotp); if (result.valid_p) { if (! result.value) einfo ("%F%P: %s\n", tree->assert_s.message); return result; } break; case etree_unary: result = exp_fold_tree (tree->unary.child, current_section, allocation_done, dot, dotp); if (result.valid_p) { switch (tree->type.node_code) { case ALIGN_K: if (allocation_done != lang_first_phase_enum) result = new_rel_from_section (ALIGN_N (dot, result.value), current_section); else result.valid_p = false; break; case ABSOLUTE: if (allocation_done != lang_first_phase_enum && result.valid_p) { result.value += result.section->bfd_section->vma; result.section = abs_output_section; } else result.valid_p = false; break; case '~': make_abs (&result); result.value = ~result.value; break; case '!': make_abs (&result); result.value = !result.value; break; case '-': make_abs (&result); result.value = -result.value; break; case NEXT: /* Return next place aligned to value. */ if (allocation_done == lang_allocating_phase_enum) { make_abs (&result); result.value = ALIGN_N (dot, result.value); } else result.valid_p = false; break; default: FAIL (); break; } } break; case etree_trinary: result = exp_fold_tree (tree->trinary.cond, current_section, allocation_done, dot, dotp); if (result.valid_p) result = exp_fold_tree ((result.value ? tree->trinary.lhs : tree->trinary.rhs), current_section, allocation_done, dot, dotp); break; case etree_binary: result = fold_binary (tree, current_section, allocation_done, dot, dotp); break; case etree_assign: case etree_provide: 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_provide) einfo (_("%F%S can not PROVIDE assignment to location counter\n")); if (allocation_done == lang_allocating_phase_enum || (allocation_done == lang_final_phase_enum && current_section == abs_output_section)) { result = exp_fold_tree (tree->assign.src, current_section, lang_allocating_phase_enum, dot, dotp); if (! result.valid_p) einfo (_("%F%S invalid assignment to location counter\n")); else { if (current_section == NULL) einfo (_("%F%S assignment to location counter invalid outside of SECTION\n")); else { bfd_vma nextdot; nextdot = (result.value + current_section->bfd_section->vma); if (nextdot < dot && current_section != abs_output_section) { einfo (_("%F%S cannot move location counter backwards (from %V to %V)\n"), dot, nextdot); } else *dotp = nextdot; } } } } else { result = exp_fold_tree (tree->assign.src, current_section, allocation_done, dot, dotp); if (result.valid_p) { boolean create; struct bfd_link_hash_entry *h; if (tree->type.node_class == etree_assign) create = true; else create = false; h = bfd_link_hash_lookup (link_info.hash, tree->assign.dst, create, false, false); if (h == (struct bfd_link_hash_entry *) NULL) { if (tree->type.node_class == etree_assign) einfo (_("%P%F:%s: hash creation failed\n"), tree->assign.dst); } else if (tree->type.node_class == etree_provide && h->type != bfd_link_hash_undefined && h->type != bfd_link_hash_common) { /* Do nothing. The symbol was defined by some object. */ } else { /* FIXME: Should we worry if the symbol is already defined? */ h->type = bfd_link_hash_defined; h->u.def.value = result.value; h->u.def.section = result.section->bfd_section; } } } break; case etree_name: result = fold_name (tree, current_section, allocation_done, dot); break; default: FAIL (); break; } return result; } static etree_value_type exp_fold_tree_no_dot (tree, current_section, allocation_done) etree_type *tree; lang_output_section_statement_type *current_section; lang_phase_type allocation_done; { return exp_fold_tree (tree, current_section, allocation_done, (bfd_vma) 0, (bfd_vma *) NULL); } etree_type * exp_binop (code, lhs, rhs) int code; etree_type *lhs; etree_type *rhs; { etree_type value, *new; etree_value_type r; value.type.node_code = code; value.binary.lhs = lhs; value.binary.rhs = rhs; value.type.node_class = etree_binary; r = exp_fold_tree_no_dot (&value, abs_output_section, lang_first_phase_enum); if (r.valid_p) { return exp_intop (r.value); } new = (etree_type *) stat_alloc (sizeof (new->binary)); memcpy ((char *) new, (char *) &value, sizeof (new->binary)); return new; } etree_type * exp_trinop (code, cond, lhs, rhs) int code; etree_type *cond; etree_type *lhs; etree_type *rhs; { etree_type value, *new; etree_value_type r; value.type.node_code = code; value.trinary.lhs = lhs; value.trinary.cond = cond; value.trinary.rhs = rhs; value.type.node_class = etree_trinary; r = exp_fold_tree_no_dot (&value, (lang_output_section_statement_type *) NULL, lang_first_phase_enum); if (r.valid_p) { return exp_intop (r.value); } new = (etree_type *) stat_alloc (sizeof (new->trinary)); memcpy ((char *) new, (char *) &value, sizeof (new->trinary)); return new; } etree_type * exp_unop (code, child) int code; etree_type *child; { etree_type value, *new; etree_value_type r; value.unary.type.node_code = code; value.unary.child = child; value.unary.type.node_class = etree_unary; r = exp_fold_tree_no_dot (&value, abs_output_section, lang_first_phase_enum); if (r.valid_p) { return exp_intop (r.value); } new = (etree_type *) stat_alloc (sizeof (new->unary)); memcpy ((char *) new, (char *) &value, sizeof (new->unary)); return new; } etree_type * exp_nameop (code, name) int code; CONST char *name; { etree_type value, *new; etree_value_type r; value.name.type.node_code = code; value.name.name = name; value.name.type.node_class = etree_name; r = exp_fold_tree_no_dot (&value, (lang_output_section_statement_type *) NULL, lang_first_phase_enum); if (r.valid_p) { return exp_intop (r.value); } new = (etree_type *) stat_alloc (sizeof (new->name)); memcpy ((char *) new, (char *) &value, sizeof (new->name)); return new; } etree_type * exp_assop (code, dst, src) int code; CONST char *dst; etree_type *src; { etree_type value, *new; value.assign.type.node_code = code; value.assign.src = src; value.assign.dst = dst; value.assign.type.node_class = etree_assign; #if 0 if (exp_fold_tree_no_dot (&value, &result)) { return exp_intop (result); } #endif new = (etree_type *) stat_alloc (sizeof (new->assign)); memcpy ((char *) new, (char *) &value, sizeof (new->assign)); return new; } /* Handle PROVIDE. */ etree_type * exp_provide (dst, src) const char *dst; etree_type *src; { etree_type *n; n = (etree_type *) stat_alloc (sizeof (n->assign)); n->assign.type.node_code = '='; n->assign.type.node_class = etree_provide; n->assign.src = src; n->assign.dst = dst; return n; } /* Handle ASSERT. */ etree_type * exp_assert (exp, message) etree_type *exp; const char *message; { etree_type *n; n = (etree_type *) stat_alloc (sizeof (n->assert_s)); n->assert_s.type.node_code = '!'; n->assert_s.type.node_class = etree_assert; n->assert_s.child = exp; n->assert_s.message = message; return n; } void exp_print_tree (tree) etree_type *tree; { switch (tree->type.node_class) { case etree_value: minfo ("0x%v", tree->value.value); return; case etree_rel: if (tree->rel.section->owner != NULL) minfo ("%B:", tree->rel.section->owner); minfo ("%s+0x%v", tree->rel.section->name, tree->rel.value); return; case etree_assign: #if 0 if (tree->assign.dst->sdefs != (asymbol *) NULL) { fprintf (config.map_file, "%s (%x) ", tree->assign.dst->name, tree->assign.dst->sdefs->value); } else { fprintf (config.map_file, "%s (UNDEFINED)", tree->assign.dst->name); } #endif fprintf (config.map_file, "%s", tree->assign.dst); exp_print_token (tree->type.node_code); exp_print_tree (tree->assign.src); break; case etree_provide: fprintf (config.map_file, "PROVIDE (%s, ", tree->assign.dst); exp_print_tree (tree->assign.src); fprintf (config.map_file, ")"); break; case etree_binary: fprintf (config.map_file, "("); exp_print_tree (tree->binary.lhs); exp_print_token (tree->type.node_code); exp_print_tree (tree->binary.rhs); fprintf (config.map_file, ")"); break; case etree_trinary: exp_print_tree (tree->trinary.cond); fprintf (config.map_file, "?"); exp_print_tree (tree->trinary.lhs); fprintf (config.map_file, ":"); exp_print_tree (tree->trinary.rhs); break; case etree_unary: exp_print_token (tree->unary.type.node_code); if (tree->unary.child) { fprintf (config.map_file, "("); exp_print_tree (tree->unary.child); fprintf (config.map_file, ")"); } break; case etree_assert: fprintf (config.map_file, "ASSERT ("); exp_print_tree (tree->assert_s.child); fprintf (config.map_file, ", %s)", tree->assert_s.message); break; case etree_undef: fprintf (config.map_file, "????????"); break; case etree_name: if (tree->type.node_code == NAME) { fprintf (config.map_file, "%s", tree->name.name); } else { exp_print_token (tree->type.node_code); if (tree->name.name) fprintf (config.map_file, "(%s)", tree->name.name); } break; default: FAIL (); break; } } bfd_vma exp_get_vma (tree, def, name, allocation_done) etree_type *tree; bfd_vma def; char *name; lang_phase_type allocation_done; { etree_value_type r; if (tree != NULL) { r = exp_fold_tree_no_dot (tree, abs_output_section, allocation_done); if (! r.valid_p && name != NULL) einfo (_("%F%S nonconstant expression for %s\n"), name); return r.value; } else return def; } int exp_get_value_int (tree, def, name, allocation_done) etree_type *tree; int def; char *name; lang_phase_type allocation_done; { return (int) exp_get_vma (tree, (bfd_vma) def, name, allocation_done); } bfd_vma exp_get_abs_int (tree, def, name, allocation_done) etree_type *tree; int def ATTRIBUTE_UNUSED; char *name; lang_phase_type allocation_done; { etree_value_type res; res = exp_fold_tree_no_dot (tree, abs_output_section, allocation_done); if (res.valid_p) { res.value += res.section->bfd_section->vma; } else { einfo (_("%F%S non constant expression for %s\n"), name); } return res.value; }