| /* |
| * Symbol scoping. |
| * |
| * This is pretty trivial. |
| * |
| * Copyright (C) 2003 Transmeta Corp. |
| * 2003-2004 Linus Torvalds |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a copy |
| * of this software and associated documentation files (the "Software"), to deal |
| * in the Software without restriction, including without limitation the rights |
| * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| * copies of the Software, and to permit persons to whom the Software is |
| * furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be included in |
| * all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| * THE SOFTWARE. |
| */ |
| #include <stdlib.h> |
| #include <string.h> |
| #include <stdio.h> |
| |
| #include "lib.h" |
| #include "allocate.h" |
| #include "symbol.h" |
| #include "scope.h" |
| |
| static struct scope builtin_scope = { .next = &builtin_scope }; |
| |
| struct scope *block_scope = &builtin_scope, // regular automatic variables etc |
| *label_scope = NULL, // expr-stmt labels |
| *function_scope = &builtin_scope, // labels, arguments etc |
| *file_scope = &builtin_scope, // static |
| *global_scope = &builtin_scope; // externally visible |
| |
| void set_current_scope(struct symbol *sym) |
| { |
| sym->scope = block_scope; |
| } |
| |
| void bind_scope(struct symbol *sym, struct scope *scope) |
| { |
| sym->scope = scope; |
| add_symbol(&scope->symbols, sym); |
| } |
| |
| |
| void rebind_scope(struct symbol *sym, struct scope *new) |
| { |
| struct scope *old = sym->scope; |
| |
| if (old == new) |
| return; |
| |
| if (old) |
| delete_ptr_list_entry((struct ptr_list**) &old->symbols, sym, 1); |
| |
| bind_scope(sym, new); |
| } |
| |
| static void start_scope(struct scope **s) |
| { |
| struct scope *scope = __alloc_scope(0); |
| scope->next = *s; |
| *s = scope; |
| } |
| |
| void start_file_scope(void) |
| { |
| struct scope *scope = __alloc_scope(0); |
| |
| scope->next = &builtin_scope; |
| file_scope = scope; |
| |
| /* top-level stuff defaults to file scope, "extern" etc will choose global scope */ |
| function_scope = scope; |
| block_scope = scope; |
| } |
| |
| void start_block_scope(void) |
| { |
| start_scope(&block_scope); |
| } |
| |
| void start_function_scope(void) |
| { |
| start_scope(&block_scope); |
| start_scope(&label_scope); |
| function_scope = label_scope; |
| } |
| |
| static void remove_symbol_scope(struct symbol *sym) |
| { |
| struct symbol **ptr = &sym->ident->symbols; |
| |
| while (*ptr != sym) |
| ptr = &(*ptr)->next_id; |
| *ptr = sym->next_id; |
| } |
| |
| static void end_scope(struct scope **s) |
| { |
| struct scope *scope = *s; |
| struct symbol_list *symbols = scope->symbols; |
| struct symbol *sym; |
| |
| *s = scope->next; |
| scope->symbols = NULL; |
| FOR_EACH_PTR(symbols, sym) { |
| remove_symbol_scope(sym); |
| } END_FOR_EACH_PTR(sym); |
| } |
| |
| void end_file_scope(void) |
| { |
| end_scope(&file_scope); |
| } |
| |
| void new_file_scope(void) |
| { |
| if (file_scope != &builtin_scope) |
| end_file_scope(); |
| start_file_scope(); |
| } |
| |
| void end_block_scope(void) |
| { |
| end_scope(&block_scope); |
| } |
| |
| void end_function_scope(void) |
| { |
| end_scope(&block_scope); |
| end_label_scope(); |
| function_scope = label_scope; |
| } |
| |
| void start_label_scope(void) |
| { |
| start_scope(&label_scope); |
| } |
| |
| void end_label_scope(void) |
| { |
| struct symbol *sym; |
| |
| FOR_EACH_PTR(label_scope->symbols, sym) { |
| if (!sym->stmt || sym->used) |
| continue; |
| if (sym->label_modifiers & MOD_UNUSED) |
| continue; |
| warning(sym->pos, "unused label '%s'", show_ident(sym->ident)); |
| } END_FOR_EACH_PTR(sym); |
| |
| end_scope(&label_scope); |
| } |
| |
| int is_outer_scope(struct scope *scope) |
| { |
| if (scope == block_scope) |
| return 0; |
| if (scope == &builtin_scope && block_scope->next == &builtin_scope) |
| return 0; |
| return 1; |
| } |
| |
| int is_in_scope(struct scope *outer, struct scope *inner) |
| { |
| while (inner != outer) { |
| if (inner == function_scope) |
| return 0; |
| inner = inner->next; |
| } |
| return 1; |
| } |