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/*
* 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;
}
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