1/*
2 * This file is part of the MicroPython project, http://micropython.org/
3 *
4 * The MIT License (MIT)
5 *
6 * Copyright (c) 2013, 2014 Damien P. George
7 *
8 * Permission is hereby granted, free of charge, to any person obtaining a copy
9 * of this software and associated documentation files (the "Software"), to deal
10 * in the Software without restriction, including without limitation the rights
11 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
12 * copies of the Software, and to permit persons to whom the Software is
13 * furnished to do so, subject to the following conditions:
14 *
15 * The above copyright notice and this permission notice shall be included in
16 * all copies or substantial portions of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
21 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
23 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24 * THE SOFTWARE.
25 */
26
27#include <assert.h>
28
29#include "py/scope.h"
30
31#if MICROPY_ENABLE_COMPILER
32
33// These low numbered qstrs should fit in 8 bits. See assertions below.
34STATIC const uint8_t scope_simple_name_table[] = {
35 [SCOPE_MODULE] = MP_QSTR__lt_module_gt_,
36 [SCOPE_LAMBDA] = MP_QSTR__lt_lambda_gt_,
37 [SCOPE_LIST_COMP] = MP_QSTR__lt_listcomp_gt_,
38 [SCOPE_DICT_COMP] = MP_QSTR__lt_dictcomp_gt_,
39 [SCOPE_SET_COMP] = MP_QSTR__lt_setcomp_gt_,
40 [SCOPE_GEN_EXPR] = MP_QSTR__lt_genexpr_gt_,
41};
42
43scope_t *scope_new(scope_kind_t kind, mp_parse_node_t pn, qstr source_file, mp_uint_t emit_options) {
44 // Make sure those qstrs indeed fit in an uint8_t.
45 MP_STATIC_ASSERT(MP_QSTR__lt_module_gt_ <= UINT8_MAX);
46 MP_STATIC_ASSERT(MP_QSTR__lt_lambda_gt_ <= UINT8_MAX);
47 MP_STATIC_ASSERT(MP_QSTR__lt_listcomp_gt_ <= UINT8_MAX);
48 MP_STATIC_ASSERT(MP_QSTR__lt_dictcomp_gt_ <= UINT8_MAX);
49 MP_STATIC_ASSERT(MP_QSTR__lt_setcomp_gt_ <= UINT8_MAX);
50 MP_STATIC_ASSERT(MP_QSTR__lt_genexpr_gt_ <= UINT8_MAX);
51
52 scope_t *scope = m_new0(scope_t, 1);
53 scope->kind = kind;
54 scope->pn = pn;
55 scope->source_file = source_file;
56 if (kind == SCOPE_FUNCTION || kind == SCOPE_CLASS) {
57 assert(MP_PARSE_NODE_IS_STRUCT(pn));
58 scope->simple_name = MP_PARSE_NODE_LEAF_ARG(((mp_parse_node_struct_t *)pn)->nodes[0]);
59 } else {
60 scope->simple_name = scope_simple_name_table[kind];
61 }
62 scope->raw_code = mp_emit_glue_new_raw_code();
63 scope->emit_options = emit_options;
64 scope->id_info_alloc = MICROPY_ALLOC_SCOPE_ID_INIT;
65 scope->id_info = m_new(id_info_t, scope->id_info_alloc);
66
67 return scope;
68}
69
70void scope_free(scope_t *scope) {
71 m_del(id_info_t, scope->id_info, scope->id_info_alloc);
72 m_del(scope_t, scope, 1);
73}
74
75id_info_t *scope_find_or_add_id(scope_t *scope, qstr qst, id_info_kind_t kind) {
76 id_info_t *id_info = scope_find(scope, qst);
77 if (id_info != NULL) {
78 return id_info;
79 }
80
81 // make sure we have enough memory
82 if (scope->id_info_len >= scope->id_info_alloc) {
83 scope->id_info = m_renew(id_info_t, scope->id_info, scope->id_info_alloc, scope->id_info_alloc + MICROPY_ALLOC_SCOPE_ID_INC);
84 scope->id_info_alloc += MICROPY_ALLOC_SCOPE_ID_INC;
85 }
86
87 // add new id to end of array of all ids; this seems to match CPython
88 // important thing is that function arguments are first, but that is
89 // handled by the compiler because it adds arguments before compiling the body
90 id_info = &scope->id_info[scope->id_info_len++];
91
92 id_info->kind = kind;
93 id_info->flags = 0;
94 id_info->local_num = 0;
95 id_info->qst = qst;
96 return id_info;
97}
98
99id_info_t *scope_find(scope_t *scope, qstr qst) {
100 for (mp_uint_t i = 0; i < scope->id_info_len; i++) {
101 if (scope->id_info[i].qst == qst) {
102 return &scope->id_info[i];
103 }
104 }
105 return NULL;
106}
107
108id_info_t *scope_find_global(scope_t *scope, qstr qst) {
109 while (scope->parent != NULL) {
110 scope = scope->parent;
111 }
112 return scope_find(scope, qst);
113}
114
115STATIC void scope_close_over_in_parents(scope_t *scope, qstr qst) {
116 assert(scope->parent != NULL); // we should have at least 1 parent
117 for (scope_t *s = scope->parent;; s = s->parent) {
118 assert(s->parent != NULL); // we should not get to the outer scope
119 id_info_t *id = scope_find_or_add_id(s, qst, ID_INFO_KIND_UNDECIDED);
120 if (id->kind == ID_INFO_KIND_UNDECIDED) {
121 // variable not previously declared in this scope, so declare it as free and keep searching parents
122 id->kind = ID_INFO_KIND_FREE;
123 } else {
124 // variable is declared in this scope, so finish
125 if (id->kind == ID_INFO_KIND_LOCAL) {
126 // variable local to this scope, close it over
127 id->kind = ID_INFO_KIND_CELL;
128 } else {
129 // ID_INFO_KIND_FREE: variable already closed over in a parent scope
130 // ID_INFO_KIND_CELL: variable already closed over in this scope
131 assert(id->kind == ID_INFO_KIND_FREE || id->kind == ID_INFO_KIND_CELL);
132 }
133 return;
134 }
135 }
136}
137
138void scope_check_to_close_over(scope_t *scope, id_info_t *id) {
139 if (scope->parent != NULL) {
140 for (scope_t *s = scope->parent; s->parent != NULL; s = s->parent) {
141 id_info_t *id2 = scope_find(s, id->qst);
142 if (id2 != NULL) {
143 if (id2->kind == ID_INFO_KIND_LOCAL || id2->kind == ID_INFO_KIND_CELL || id2->kind == ID_INFO_KIND_FREE) {
144 id->kind = ID_INFO_KIND_FREE;
145 scope_close_over_in_parents(scope, id->qst);
146 }
147 break;
148 }
149 }
150 }
151}
152
153#endif // MICROPY_ENABLE_COMPILER
154