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circuitpython/py/parse.c
Damien George 1f1d5194d7 py/objstr: Make mp_obj_new_str_of_type check for existing interned qstr. 
The function mp_obj_new_str_of_type is a general str object constructor
used in many places in the code to create either a str or bytes object.
When creating a str it should first check if the string data already exists
as an interned qstr, and if so then return the qstr object.  This patch
makes the function have such behaviour, which helps to reduce heap usage by
reusing existing interned data where possible.

The old behaviour of mp_obj_new_str_of_type (which didn't check for
existing interned data) is made available through the function
mp_obj_new_str_copy, but should only be used in very special cases.

One consequence of this patch is that the following expression is now True:

    'abc' is ' abc '.split()[0]
2017-11-16 13:53:04 +11:00

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/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2013-2015 Damien P. George
*
* 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 <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <unistd.h> // for ssize_t
#include <assert.h>
#include <string.h>
#include "py/lexer.h"
#include "py/parse.h"
#include "py/parsenum.h"
#include "py/runtime.h"
#include "py/objint.h"
#include "py/objstr.h"
#include "py/builtin.h"
#if MICROPY_ENABLE_COMPILER
#define RULE_ACT_ARG_MASK (0x0f)
#define RULE_ACT_KIND_MASK (0x30)
#define RULE_ACT_ALLOW_IDENT (0x40)
#define RULE_ACT_ADD_BLANK (0x80)
#define RULE_ACT_OR (0x10)
#define RULE_ACT_AND (0x20)
#define RULE_ACT_LIST (0x30)
#define RULE_ARG_KIND_MASK (0xf000)
#define RULE_ARG_ARG_MASK (0x0fff)
#define RULE_ARG_TOK (0x1000)
#define RULE_ARG_RULE (0x2000)
#define RULE_ARG_OPT_RULE (0x3000)
// (un)comment to use rule names; for debugging
//#define USE_RULE_NAME (1)
typedef struct _rule_t {
byte rule_id;
byte act;
#ifdef USE_RULE_NAME
const char *rule_name;
#endif
uint16_t arg[];
} rule_t;
enum {
// define rules with a compile function
#define DEF_RULE(rule, comp, kind, ...) RULE_##rule,
#define DEF_RULE_NC(rule, kind, ...)
#include "py/grammar.h"
#undef DEF_RULE
#undef DEF_RULE_NC
RULE_const_object, // special node for a constant, generic Python object
// define rules without a compile function
#define DEF_RULE(rule, comp, kind, ...)
#define DEF_RULE_NC(rule, kind, ...) RULE_##rule,
#include "py/grammar.h"
#undef DEF_RULE
#undef DEF_RULE_NC
};
#define or(n) (RULE_ACT_OR | n)
#define and(n) (RULE_ACT_AND | n)
#define and_ident(n) (RULE_ACT_AND | n | RULE_ACT_ALLOW_IDENT)
#define and_blank(n) (RULE_ACT_AND | n | RULE_ACT_ADD_BLANK)
#define one_or_more (RULE_ACT_LIST | 2)
#define list (RULE_ACT_LIST | 1)
#define list_with_end (RULE_ACT_LIST | 3)
#define tok(t) (RULE_ARG_TOK | MP_TOKEN_##t)
#define rule(r) (RULE_ARG_RULE | RULE_##r)
#define opt_rule(r) (RULE_ARG_OPT_RULE | RULE_##r)
#ifdef USE_RULE_NAME
#define DEF_RULE(rule, comp, kind, ...) static const rule_t rule_##rule = { RULE_##rule, kind, #rule, { __VA_ARGS__ } };
#define DEF_RULE_NC(rule, kind, ...) static const rule_t rule_##rule = { RULE_##rule, kind, #rule, { __VA_ARGS__ } };
#else
#define DEF_RULE(rule, comp, kind, ...) static const rule_t rule_##rule = { RULE_##rule, kind, { __VA_ARGS__ } };
#define DEF_RULE_NC(rule, kind, ...) static const rule_t rule_##rule = { RULE_##rule, kind, { __VA_ARGS__ } };
#endif
#include "py/grammar.h"
#undef or
#undef and
#undef list
#undef list_with_end
#undef tok
#undef rule
#undef opt_rule
#undef one_or_more
#undef DEF_RULE
#undef DEF_RULE_NC
STATIC const rule_t *const rules[] = {
// define rules with a compile function
#define DEF_RULE(rule, comp, kind, ...) &rule_##rule,
#define DEF_RULE_NC(rule, kind, ...)
#include "py/grammar.h"
#undef DEF_RULE
#undef DEF_RULE_NC
NULL, // RULE_const_object
// define rules without a compile function
#define DEF_RULE(rule, comp, kind, ...)
#define DEF_RULE_NC(rule, kind, ...) &rule_##rule,
#include "py/grammar.h"
#undef DEF_RULE
#undef DEF_RULE_NC
};
typedef struct _rule_stack_t {
size_t src_line : 8 * sizeof(size_t) - 8; // maximum bits storing source line number
size_t rule_id : 8; // this must be large enough to fit largest rule number
size_t arg_i; // this dictates the maximum nodes in a "list" of things
} rule_stack_t;
typedef struct _mp_parse_chunk_t {
size_t alloc;
union {
size_t used;
struct _mp_parse_chunk_t *next;
} union_;
byte data[];
} mp_parse_chunk_t;
typedef struct _parser_t {
size_t rule_stack_alloc;
size_t rule_stack_top;
rule_stack_t *rule_stack;
size_t result_stack_alloc;
size_t result_stack_top;
mp_parse_node_t *result_stack;
mp_lexer_t *lexer;
mp_parse_tree_t tree;
mp_parse_chunk_t *cur_chunk;
#if MICROPY_COMP_CONST
mp_map_t consts;
#endif
} parser_t;
STATIC void *parser_alloc(parser_t *parser, size_t num_bytes) {
// use a custom memory allocator to store parse nodes sequentially in large chunks
mp_parse_chunk_t *chunk = parser->cur_chunk;
if (chunk != NULL && chunk->union_.used + num_bytes > chunk->alloc) {
// not enough room at end of previously allocated chunk so try to grow
mp_parse_chunk_t *new_data = (mp_parse_chunk_t*)m_renew_maybe(byte, chunk,
sizeof(mp_parse_chunk_t) + chunk->alloc,
sizeof(mp_parse_chunk_t) + chunk->alloc + num_bytes, false);
if (new_data == NULL) {
// could not grow existing memory; shrink it to fit previous
(void)m_renew_maybe(byte, chunk, sizeof(mp_parse_chunk_t) + chunk->alloc,
sizeof(mp_parse_chunk_t) + chunk->union_.used, false);
chunk->alloc = chunk->union_.used;
chunk->union_.next = parser->tree.chunk;
parser->tree.chunk = chunk;
chunk = NULL;
} else {
// could grow existing memory
chunk->alloc += num_bytes;
}
}
if (chunk == NULL) {
// no previous chunk, allocate a new chunk
size_t alloc = MICROPY_ALLOC_PARSE_CHUNK_INIT;
if (alloc < num_bytes) {
alloc = num_bytes;
}
chunk = (mp_parse_chunk_t*)m_new(byte, sizeof(mp_parse_chunk_t) + alloc);
chunk->alloc = alloc;
chunk->union_.used = 0;
parser->cur_chunk = chunk;
}
byte *ret = chunk->data + chunk->union_.used;
chunk->union_.used += num_bytes;
return ret;
}
STATIC void push_rule(parser_t *parser, size_t src_line, const rule_t *rule, size_t arg_i) {
if (parser->rule_stack_top >= parser->rule_stack_alloc) {
rule_stack_t *rs = m_renew(rule_stack_t, parser->rule_stack, parser->rule_stack_alloc, parser->rule_stack_alloc + MICROPY_ALLOC_PARSE_RULE_INC);
parser->rule_stack = rs;
parser->rule_stack_alloc += MICROPY_ALLOC_PARSE_RULE_INC;
}
rule_stack_t *rs = &parser->rule_stack[parser->rule_stack_top++];
rs->src_line = src_line;
rs->rule_id = rule->rule_id;
rs->arg_i = arg_i;
}
STATIC void push_rule_from_arg(parser_t *parser, size_t arg) {
assert((arg & RULE_ARG_KIND_MASK) == RULE_ARG_RULE || (arg & RULE_ARG_KIND_MASK) == RULE_ARG_OPT_RULE);
size_t rule_id = arg & RULE_ARG_ARG_MASK;
push_rule(parser, parser->lexer->tok_line, rules[rule_id], 0);
}
STATIC void pop_rule(parser_t *parser, const rule_t **rule, size_t *arg_i, size_t *src_line) {
parser->rule_stack_top -= 1;
*rule = rules[parser->rule_stack[parser->rule_stack_top].rule_id];
*arg_i = parser->rule_stack[parser->rule_stack_top].arg_i;
*src_line = parser->rule_stack[parser->rule_stack_top].src_line;
}
bool mp_parse_node_is_const_false(mp_parse_node_t pn) {
return MP_PARSE_NODE_IS_TOKEN_KIND(pn, MP_TOKEN_KW_FALSE)
|| (MP_PARSE_NODE_IS_SMALL_INT(pn) && MP_PARSE_NODE_LEAF_SMALL_INT(pn) == 0);
}
bool mp_parse_node_is_const_true(mp_parse_node_t pn) {
return MP_PARSE_NODE_IS_TOKEN_KIND(pn, MP_TOKEN_KW_TRUE)
|| (MP_PARSE_NODE_IS_SMALL_INT(pn) && MP_PARSE_NODE_LEAF_SMALL_INT(pn) != 0);
}
bool mp_parse_node_get_int_maybe(mp_parse_node_t pn, mp_obj_t *o) {
if (MP_PARSE_NODE_IS_SMALL_INT(pn)) {
*o = MP_OBJ_NEW_SMALL_INT(MP_PARSE_NODE_LEAF_SMALL_INT(pn));
return true;
} else if (MP_PARSE_NODE_IS_STRUCT_KIND(pn, RULE_const_object)) {
mp_parse_node_struct_t *pns = (mp_parse_node_struct_t*)pn;
#if MICROPY_OBJ_REPR == MICROPY_OBJ_REPR_D
// nodes are 32-bit pointers, but need to extract 64-bit object
*o = (uint64_t)pns->nodes[0] | ((uint64_t)pns->nodes[1] << 32);
#else
*o = (mp_obj_t)pns->nodes[0];
#endif
return MP_OBJ_IS_INT(*o);
} else {
return false;
}
}
int mp_parse_node_extract_list(mp_parse_node_t *pn, size_t pn_kind, mp_parse_node_t **nodes) {
if (MP_PARSE_NODE_IS_NULL(*pn)) {
*nodes = NULL;
return 0;
} else if (MP_PARSE_NODE_IS_LEAF(*pn)) {
*nodes = pn;
return 1;
} else {
mp_parse_node_struct_t *pns = (mp_parse_node_struct_t*)(*pn);
if (MP_PARSE_NODE_STRUCT_KIND(pns) != pn_kind) {
*nodes = pn;
return 1;
} else {
*nodes = pns->nodes;
return MP_PARSE_NODE_STRUCT_NUM_NODES(pns);
}
}
}
#if MICROPY_DEBUG_PRINTERS
void mp_parse_node_print(mp_parse_node_t pn, size_t indent) {
if (MP_PARSE_NODE_IS_STRUCT(pn)) {
printf("[% 4d] ", (int)((mp_parse_node_struct_t*)pn)->source_line);
} else {
printf(" ");
}
for (size_t i = 0; i < indent; i++) {
printf(" ");
}
if (MP_PARSE_NODE_IS_NULL(pn)) {
printf("NULL\n");
} else if (MP_PARSE_NODE_IS_SMALL_INT(pn)) {
mp_int_t arg = MP_PARSE_NODE_LEAF_SMALL_INT(pn);
printf("int(" INT_FMT ")\n", arg);
} else if (MP_PARSE_NODE_IS_LEAF(pn)) {
uintptr_t arg = MP_PARSE_NODE_LEAF_ARG(pn);
switch (MP_PARSE_NODE_LEAF_KIND(pn)) {
case MP_PARSE_NODE_ID: printf("id(%s)\n", qstr_str(arg)); break;
case MP_PARSE_NODE_STRING: printf("str(%s)\n", qstr_str(arg)); break;
case MP_PARSE_NODE_BYTES: printf("bytes(%s)\n", qstr_str(arg)); break;
default:
assert(MP_PARSE_NODE_LEAF_KIND(pn) == MP_PARSE_NODE_TOKEN);
printf("tok(%u)\n", (uint)arg); break;
}
} else {
// node must be a mp_parse_node_struct_t
mp_parse_node_struct_t *pns = (mp_parse_node_struct_t*)pn;
if (MP_PARSE_NODE_STRUCT_KIND(pns) == RULE_const_object) {
#if MICROPY_OBJ_REPR == MICROPY_OBJ_REPR_D
printf("literal const(%016llx)\n", (uint64_t)pns->nodes[0] | ((uint64_t)pns->nodes[1] << 32));
#else
printf("literal const(%p)\n", (mp_obj_t)pns->nodes[0]);
#endif
} else {
size_t n = MP_PARSE_NODE_STRUCT_NUM_NODES(pns);
#ifdef USE_RULE_NAME
printf("%s(%u) (n=%u)\n", rules[MP_PARSE_NODE_STRUCT_KIND(pns)]->rule_name, (uint)MP_PARSE_NODE_STRUCT_KIND(pns), (uint)n);
#else
printf("rule(%u) (n=%u)\n", (uint)MP_PARSE_NODE_STRUCT_KIND(pns), (uint)n);
#endif
for (size_t i = 0; i < n; i++) {
mp_parse_node_print(pns->nodes[i], indent + 2);
}
}
}
}
#endif // MICROPY_DEBUG_PRINTERS
/*
STATIC void result_stack_show(parser_t *parser) {
printf("result stack, most recent first\n");
for (ssize_t i = parser->result_stack_top - 1; i >= 0; i--) {
mp_parse_node_print(parser->result_stack[i], 0);
}
}
*/
STATIC mp_parse_node_t pop_result(parser_t *parser) {
assert(parser->result_stack_top > 0);
return parser->result_stack[--parser->result_stack_top];
}
STATIC mp_parse_node_t peek_result(parser_t *parser, size_t pos) {
assert(parser->result_stack_top > pos);
return parser->result_stack[parser->result_stack_top - 1 - pos];
}
STATIC void push_result_node(parser_t *parser, mp_parse_node_t pn) {
if (parser->result_stack_top >= parser->result_stack_alloc) {
mp_parse_node_t *stack = m_renew(mp_parse_node_t, parser->result_stack, parser->result_stack_alloc, parser->result_stack_alloc + MICROPY_ALLOC_PARSE_RESULT_INC);
parser->result_stack = stack;
parser->result_stack_alloc += MICROPY_ALLOC_PARSE_RESULT_INC;
}
parser->result_stack[parser->result_stack_top++] = pn;
}
STATIC mp_parse_node_t make_node_const_object(parser_t *parser, size_t src_line, mp_obj_t obj) {
mp_parse_node_struct_t *pn = parser_alloc(parser, sizeof(mp_parse_node_struct_t) + sizeof(mp_obj_t));
pn->source_line = src_line;
#if MICROPY_OBJ_REPR == MICROPY_OBJ_REPR_D
// nodes are 32-bit pointers, but need to store 64-bit object
pn->kind_num_nodes = RULE_const_object | (2 << 8);
pn->nodes[0] = (uint64_t)obj;
pn->nodes[1] = (uint64_t)obj >> 32;
#else
pn->kind_num_nodes = RULE_const_object | (1 << 8);
pn->nodes[0] = (uintptr_t)obj;
#endif
return (mp_parse_node_t)pn;
}
STATIC void push_result_token(parser_t *parser, const rule_t *rule) {
mp_parse_node_t pn;
mp_lexer_t *lex = parser->lexer;
if (lex->tok_kind == MP_TOKEN_NAME) {
qstr id = qstr_from_strn(lex->vstr.buf, lex->vstr.len);
#if MICROPY_COMP_CONST
// if name is a standalone identifier, look it up in the table of dynamic constants
mp_map_elem_t *elem;
if (rule->rule_id == RULE_atom
&& (elem = mp_map_lookup(&parser->consts, MP_OBJ_NEW_QSTR(id), MP_MAP_LOOKUP)) != NULL) {
if (MP_OBJ_IS_SMALL_INT(elem->value)) {
pn = mp_parse_node_new_small_int(MP_OBJ_SMALL_INT_VALUE(elem->value));
} else {
pn = make_node_const_object(parser, lex->tok_line, elem->value);
}
} else {
pn = mp_parse_node_new_leaf(MP_PARSE_NODE_ID, id);
}
#else
(void)rule;
pn = mp_parse_node_new_leaf(MP_PARSE_NODE_ID, id);
#endif
} else if (lex->tok_kind == MP_TOKEN_INTEGER) {
mp_obj_t o = mp_parse_num_integer(lex->vstr.buf, lex->vstr.len, 0, lex);
if (MP_OBJ_IS_SMALL_INT(o)) {
pn = mp_parse_node_new_small_int(MP_OBJ_SMALL_INT_VALUE(o));
} else {
pn = make_node_const_object(parser, lex->tok_line, o);
}
} else if (lex->tok_kind == MP_TOKEN_FLOAT_OR_IMAG) {
mp_obj_t o = mp_parse_num_decimal(lex->vstr.buf, lex->vstr.len, true, false, lex);
pn = make_node_const_object(parser, lex->tok_line, o);
} else if (lex->tok_kind == MP_TOKEN_STRING || lex->tok_kind == MP_TOKEN_BYTES) {
// Don't automatically intern all strings/bytes. doc strings (which are usually large)
// will be discarded by the compiler, and so we shouldn't intern them.
qstr qst = MP_QSTR_NULL;
if (lex->vstr.len <= MICROPY_ALLOC_PARSE_INTERN_STRING_LEN) {
// intern short strings
qst = qstr_from_strn(lex->vstr.buf, lex->vstr.len);
} else {
// check if this string is already interned
qst = qstr_find_strn(lex->vstr.buf, lex->vstr.len);
}
if (qst != MP_QSTR_NULL) {
// qstr exists, make a leaf node
pn = mp_parse_node_new_leaf(lex->tok_kind == MP_TOKEN_STRING ? MP_PARSE_NODE_STRING : MP_PARSE_NODE_BYTES, qst);
} else {
// not interned, make a node holding a pointer to the string/bytes object
mp_obj_t o = mp_obj_new_str_copy(
lex->tok_kind == MP_TOKEN_STRING ? &mp_type_str : &mp_type_bytes,
(const byte*)lex->vstr.buf, lex->vstr.len);
pn = make_node_const_object(parser, lex->tok_line, o);
}
} else {
pn = mp_parse_node_new_leaf(MP_PARSE_NODE_TOKEN, lex->tok_kind);
}
push_result_node(parser, pn);
}
#if MICROPY_COMP_MODULE_CONST
STATIC const mp_rom_map_elem_t mp_constants_table[] = {
#if MICROPY_PY_UERRNO
{ MP_ROM_QSTR(MP_QSTR_errno), MP_ROM_PTR(&mp_module_uerrno) },
#endif
#if MICROPY_PY_UCTYPES
{ MP_ROM_QSTR(MP_QSTR_uctypes), MP_ROM_PTR(&mp_module_uctypes) },
#endif
// Extra constants as defined by a port
MICROPY_PORT_CONSTANTS
};
STATIC MP_DEFINE_CONST_MAP(mp_constants_map, mp_constants_table);
#endif
STATIC void push_result_rule(parser_t *parser, size_t src_line, const rule_t *rule, size_t num_args);
#if MICROPY_COMP_CONST_FOLDING
STATIC bool fold_logical_constants(parser_t *parser, const rule_t *rule, size_t *num_args) {
if (rule->rule_id == RULE_or_test
|| rule->rule_id == RULE_and_test) {
// folding for binary logical ops: or and
size_t copy_to = *num_args;
for (size_t i = copy_to; i > 0;) {
mp_parse_node_t pn = peek_result(parser, --i);
parser->result_stack[parser->result_stack_top - copy_to] = pn;
if (i == 0) {
// always need to keep the last value
break;
}
if (rule->rule_id == RULE_or_test) {
if (mp_parse_node_is_const_true(pn)) {
//
break;
} else if (!mp_parse_node_is_const_false(pn)) {
copy_to -= 1;
}
} else {
// RULE_and_test
if (mp_parse_node_is_const_false(pn)) {
break;
} else if (!mp_parse_node_is_const_true(pn)) {
copy_to -= 1;
}
}
}
copy_to -= 1; // copy_to now contains number of args to pop
// pop and discard all the short-circuited expressions
for (size_t i = 0; i < copy_to; ++i) {
pop_result(parser);
}
*num_args -= copy_to;
// we did a complete folding if there's only 1 arg left
return *num_args == 1;
} else if (rule->rule_id == RULE_not_test_2) {
// folding for unary logical op: not
mp_parse_node_t pn = peek_result(parser, 0);
if (mp_parse_node_is_const_false(pn)) {
pn = mp_parse_node_new_leaf(MP_PARSE_NODE_TOKEN, MP_TOKEN_KW_TRUE);
} else if (mp_parse_node_is_const_true(pn)) {
pn = mp_parse_node_new_leaf(MP_PARSE_NODE_TOKEN, MP_TOKEN_KW_FALSE);
} else {
return false;
}
pop_result(parser);
push_result_node(parser, pn);
return true;
}
return false;
}
STATIC bool fold_constants(parser_t *parser, const rule_t *rule, size_t num_args) {
// this code does folding of arbitrary integer expressions, eg 1 + 2 * 3 + 4
// it does not do partial folding, eg 1 + 2 + x -> 3 + x
mp_obj_t arg0;
if (rule->rule_id == RULE_expr
|| rule->rule_id == RULE_xor_expr
|| rule->rule_id == RULE_and_expr) {
// folding for binary ops: | ^ &
mp_parse_node_t pn = peek_result(parser, num_args - 1);
if (!mp_parse_node_get_int_maybe(pn, &arg0)) {
return false;
}
mp_binary_op_t op;
if (rule->rule_id == RULE_expr) {
op = MP_BINARY_OP_OR;
} else if (rule->rule_id == RULE_xor_expr) {
op = MP_BINARY_OP_XOR;
} else {
op = MP_BINARY_OP_AND;
}
for (ssize_t i = num_args - 2; i >= 0; --i) {
pn = peek_result(parser, i);
mp_obj_t arg1;
if (!mp_parse_node_get_int_maybe(pn, &arg1)) {
return false;
}
arg0 = mp_binary_op(op, arg0, arg1);
}
} else if (rule->rule_id == RULE_shift_expr
|| rule->rule_id == RULE_arith_expr
|| rule->rule_id == RULE_term) {
// folding for binary ops: << >> + - * / % //
mp_parse_node_t pn = peek_result(parser, num_args - 1);
if (!mp_parse_node_get_int_maybe(pn, &arg0)) {
return false;
}
for (ssize_t i = num_args - 2; i >= 1; i -= 2) {
pn = peek_result(parser, i - 1);
mp_obj_t arg1;
if (!mp_parse_node_get_int_maybe(pn, &arg1)) {
return false;
}
mp_token_kind_t tok = MP_PARSE_NODE_LEAF_ARG(peek_result(parser, i));
static const uint8_t token_to_op[] = {
MP_BINARY_OP_ADD,
MP_BINARY_OP_SUBTRACT,
MP_BINARY_OP_MULTIPLY,
255,//MP_BINARY_OP_POWER,
255,//MP_BINARY_OP_TRUE_DIVIDE,
MP_BINARY_OP_FLOOR_DIVIDE,
MP_BINARY_OP_MODULO,
255,//MP_BINARY_OP_LESS
MP_BINARY_OP_LSHIFT,
255,//MP_BINARY_OP_MORE
MP_BINARY_OP_RSHIFT,
};
mp_binary_op_t op = token_to_op[tok - MP_TOKEN_OP_PLUS];
if (op == (mp_binary_op_t)255) {
return false;
}
int rhs_sign = mp_obj_int_sign(arg1);
if (op <= MP_BINARY_OP_RSHIFT) {
// << and >> can't have negative rhs
if (rhs_sign < 0) {
return false;
}
} else if (op >= MP_BINARY_OP_FLOOR_DIVIDE) {
// % and // can't have zero rhs
if (rhs_sign == 0) {
return false;
}
}
arg0 = mp_binary_op(op, arg0, arg1);
}
} else if (rule->rule_id == RULE_factor_2) {
// folding for unary ops: + - ~
mp_parse_node_t pn = peek_result(parser, 0);
if (!mp_parse_node_get_int_maybe(pn, &arg0)) {
return false;
}
mp_token_kind_t tok = MP_PARSE_NODE_LEAF_ARG(peek_result(parser, 1));
mp_unary_op_t op;
if (tok == MP_TOKEN_OP_PLUS) {
op = MP_UNARY_OP_POSITIVE;
} else if (tok == MP_TOKEN_OP_MINUS) {
op = MP_UNARY_OP_NEGATIVE;
} else {
assert(tok == MP_TOKEN_OP_TILDE); // should be
op = MP_UNARY_OP_INVERT;
}
arg0 = mp_unary_op(op, arg0);
#if MICROPY_COMP_CONST
} else if (rule->rule_id == RULE_expr_stmt) {
mp_parse_node_t pn1 = peek_result(parser, 0);
if (!MP_PARSE_NODE_IS_NULL(pn1)
&& !(MP_PARSE_NODE_IS_STRUCT_KIND(pn1, RULE_expr_stmt_augassign)
|| MP_PARSE_NODE_IS_STRUCT_KIND(pn1, RULE_expr_stmt_assign_list))) {
// this node is of the form <x> = <y>
mp_parse_node_t pn0 = peek_result(parser, 1);
if (MP_PARSE_NODE_IS_ID(pn0)
&& MP_PARSE_NODE_IS_STRUCT_KIND(pn1, RULE_atom_expr_normal)
&& MP_PARSE_NODE_IS_ID(((mp_parse_node_struct_t*)pn1)->nodes[0])
&& MP_PARSE_NODE_LEAF_ARG(((mp_parse_node_struct_t*)pn1)->nodes[0]) == MP_QSTR_const
&& MP_PARSE_NODE_IS_STRUCT_KIND(((mp_parse_node_struct_t*)pn1)->nodes[1], RULE_trailer_paren)
) {
// code to assign dynamic constants: id = const(value)
// get the id
qstr id = MP_PARSE_NODE_LEAF_ARG(pn0);
// get the value
mp_parse_node_t pn_value = ((mp_parse_node_struct_t*)((mp_parse_node_struct_t*)pn1)->nodes[1])->nodes[0];
mp_obj_t value;
if (!mp_parse_node_get_int_maybe(pn_value, &value)) {
mp_obj_t exc = mp_obj_new_exception_msg(&mp_type_SyntaxError,
"constant must be an integer");
mp_obj_exception_add_traceback(exc, parser->lexer->source_name,
((mp_parse_node_struct_t*)pn1)->source_line, MP_QSTR_NULL);
nlr_raise(exc);
}
// store the value in the table of dynamic constants
mp_map_elem_t *elem = mp_map_lookup(&parser->consts, MP_OBJ_NEW_QSTR(id), MP_MAP_LOOKUP_ADD_IF_NOT_FOUND);
assert(elem->value == MP_OBJ_NULL);
elem->value = value;
// If the constant starts with an underscore then treat it as a private
// variable and don't emit any code to store the value to the id.
if (qstr_str(id)[0] == '_') {
pop_result(parser); // pop const(value)
pop_result(parser); // pop id
push_result_rule(parser, 0, rules[RULE_pass_stmt], 0); // replace with "pass"
return true;
}
// replace const(value) with value
pop_result(parser);
push_result_node(parser, pn_value);
// finished folding this assignment, but we still want it to be part of the tree
return false;
}
}
return false;
#endif
#if MICROPY_COMP_MODULE_CONST
} else if (rule->rule_id == RULE_atom_expr_normal) {
mp_parse_node_t pn0 = peek_result(parser, 1);
mp_parse_node_t pn1 = peek_result(parser, 0);
if (!(MP_PARSE_NODE_IS_ID(pn0)
&& MP_PARSE_NODE_IS_STRUCT_KIND(pn1, RULE_trailer_period))) {
return false;
}
// id1.id2
// look it up in constant table, see if it can be replaced with an integer
mp_parse_node_struct_t *pns1 = (mp_parse_node_struct_t*)pn1;
assert(MP_PARSE_NODE_IS_ID(pns1->nodes[0]));
qstr q_base = MP_PARSE_NODE_LEAF_ARG(pn0);
qstr q_attr = MP_PARSE_NODE_LEAF_ARG(pns1->nodes[0]);
mp_map_elem_t *elem = mp_map_lookup((mp_map_t*)&mp_constants_map, MP_OBJ_NEW_QSTR(q_base), MP_MAP_LOOKUP);
if (elem == NULL) {
return false;
}
mp_obj_t dest[2];
mp_load_method_maybe(elem->value, q_attr, dest);
if (!(dest[0] != MP_OBJ_NULL && MP_OBJ_IS_INT(dest[0]) && dest[1] == MP_OBJ_NULL)) {
return false;
}
arg0 = dest[0];
#endif
} else {
return false;
}
// success folding this rule
for (size_t i = num_args; i > 0; i--) {
pop_result(parser);
}
if (MP_OBJ_IS_SMALL_INT(arg0)) {
push_result_node(parser, mp_parse_node_new_small_int(MP_OBJ_SMALL_INT_VALUE(arg0)));
} else {
// TODO reuse memory for parse node struct?
push_result_node(parser, make_node_const_object(parser, 0, arg0));
}
return true;
}
#endif
STATIC void push_result_rule(parser_t *parser, size_t src_line, const rule_t *rule, size_t num_args) {
// optimise away parenthesis around an expression if possible
if (rule->rule_id == RULE_atom_paren) {
// there should be just 1 arg for this rule
mp_parse_node_t pn = peek_result(parser, 0);
if (MP_PARSE_NODE_IS_NULL(pn)) {
// need to keep parenthesis for ()
} else if (MP_PARSE_NODE_IS_STRUCT_KIND(pn, RULE_testlist_comp)) {
// need to keep parenthesis for (a, b, ...)
} else {
// parenthesis around a single expression, so it's just the expression
return;
}
}
#if MICROPY_COMP_CONST_FOLDING
if (fold_logical_constants(parser, rule, &num_args)) {
// we folded this rule so return straight away
return;
}
if (fold_constants(parser, rule, num_args)) {
// we folded this rule so return straight away
return;
}
#endif
mp_parse_node_struct_t *pn = parser_alloc(parser, sizeof(mp_parse_node_struct_t) + sizeof(mp_parse_node_t) * num_args);
pn->source_line = src_line;
pn->kind_num_nodes = (rule->rule_id & 0xff) | (num_args << 8);
for (size_t i = num_args; i > 0; i--) {
pn->nodes[i - 1] = pop_result(parser);
}
push_result_node(parser, (mp_parse_node_t)pn);
}
mp_parse_tree_t mp_parse(mp_lexer_t *lex, mp_parse_input_kind_t input_kind) {
// initialise parser and allocate memory for its stacks
parser_t parser;
parser.rule_stack_alloc = MICROPY_ALLOC_PARSE_RULE_INIT;
parser.rule_stack_top = 0;
parser.rule_stack = m_new(rule_stack_t, parser.rule_stack_alloc);
parser.result_stack_alloc = MICROPY_ALLOC_PARSE_RESULT_INIT;
parser.result_stack_top = 0;
parser.result_stack = m_new(mp_parse_node_t, parser.result_stack_alloc);
parser.lexer = lex;
parser.tree.chunk = NULL;
parser.cur_chunk = NULL;
#if MICROPY_COMP_CONST
mp_map_init(&parser.consts, 0);
#endif
// work out the top-level rule to use, and push it on the stack
size_t top_level_rule;
switch (input_kind) {
case MP_PARSE_SINGLE_INPUT: top_level_rule = RULE_single_input; break;
case MP_PARSE_EVAL_INPUT: top_level_rule = RULE_eval_input; break;
default: top_level_rule = RULE_file_input;
}
push_rule(&parser, lex->tok_line, rules[top_level_rule], 0);
// parse!
size_t n, i; // state for the current rule
size_t rule_src_line; // source line for the first token matched by the current rule
bool backtrack = false;
const rule_t *rule = NULL;
for (;;) {
next_rule:
if (parser.rule_stack_top == 0) {
break;
}
pop_rule(&parser, &rule, &i, &rule_src_line);
n = rule->act & RULE_ACT_ARG_MASK;
/*
// debugging
printf("depth=%d ", parser.rule_stack_top);
for (int j = 0; j < parser.rule_stack_top; ++j) {
printf(" ");
}
printf("%s n=%d i=%d bt=%d\n", rule->rule_name, n, i, backtrack);
*/
switch (rule->act & RULE_ACT_KIND_MASK) {
case RULE_ACT_OR:
if (i > 0 && !backtrack) {
goto next_rule;
} else {
backtrack = false;
}
for (; i < n; ++i) {
uint16_t kind = rule->arg[i] & RULE_ARG_KIND_MASK;
if (kind == RULE_ARG_TOK) {
if (lex->tok_kind == (rule->arg[i] & RULE_ARG_ARG_MASK)) {
push_result_token(&parser, rule);
mp_lexer_to_next(lex);
goto next_rule;
}
} else {
assert(kind == RULE_ARG_RULE);
if (i + 1 < n) {
push_rule(&parser, rule_src_line, rule, i + 1); // save this or-rule
}
push_rule_from_arg(&parser, rule->arg[i]); // push child of or-rule
goto next_rule;
}
}
backtrack = true;
break;
case RULE_ACT_AND: {
// failed, backtrack if we can, else syntax error
if (backtrack) {
assert(i > 0);
if ((rule->arg[i - 1] & RULE_ARG_KIND_MASK) == RULE_ARG_OPT_RULE) {
// an optional rule that failed, so continue with next arg
push_result_node(&parser, MP_PARSE_NODE_NULL);
backtrack = false;
} else {
// a mandatory rule that failed, so propagate backtrack
if (i > 1) {
// already eaten tokens so can't backtrack
goto syntax_error;
} else {
goto next_rule;
}
}
}
// progress through the rule
for (; i < n; ++i) {
if ((rule->arg[i] & RULE_ARG_KIND_MASK) == RULE_ARG_TOK) {
// need to match a token
mp_token_kind_t tok_kind = rule->arg[i] & RULE_ARG_ARG_MASK;
if (lex->tok_kind == tok_kind) {
// matched token
if (tok_kind == MP_TOKEN_NAME) {
push_result_token(&parser, rule);
}
mp_lexer_to_next(lex);
} else {
// failed to match token
if (i > 0) {
// already eaten tokens so can't backtrack
goto syntax_error;
} else {
// this rule failed, so backtrack
backtrack = true;
goto next_rule;
}
}
} else {
push_rule(&parser, rule_src_line, rule, i + 1); // save this and-rule
push_rule_from_arg(&parser, rule->arg[i]); // push child of and-rule
goto next_rule;
}
}
assert(i == n);
// matched the rule, so now build the corresponding parse_node
#if !MICROPY_ENABLE_DOC_STRING
// this code discards lonely statements, such as doc strings
if (input_kind != MP_PARSE_SINGLE_INPUT && rule->rule_id == RULE_expr_stmt && peek_result(&parser, 0) == MP_PARSE_NODE_NULL) {
mp_parse_node_t p = peek_result(&parser, 1);
if ((MP_PARSE_NODE_IS_LEAF(p) && !MP_PARSE_NODE_IS_ID(p))
|| MP_PARSE_NODE_IS_STRUCT_KIND(p, RULE_const_object)) {
pop_result(&parser); // MP_PARSE_NODE_NULL
pop_result(&parser); // const expression (leaf or RULE_const_object)
// Pushing the "pass" rule here will overwrite any RULE_const_object
// entry that was on the result stack, allowing the GC to reclaim
// the memory from the const object when needed.
push_result_rule(&parser, rule_src_line, rules[RULE_pass_stmt], 0);
break;
}
}
#endif
// count number of arguments for the parse node
i = 0;
size_t num_not_nil = 0;
for (size_t x = n; x > 0;) {
--x;
if ((rule->arg[x] & RULE_ARG_KIND_MASK) == RULE_ARG_TOK) {
mp_token_kind_t tok_kind = rule->arg[x] & RULE_ARG_ARG_MASK;
if (tok_kind == MP_TOKEN_NAME) {
// only tokens which were names are pushed to stack
i += 1;
num_not_nil += 1;
}
} else {
// rules are always pushed
if (peek_result(&parser, i) != MP_PARSE_NODE_NULL) {
num_not_nil += 1;
}
i += 1;
}
}
if (num_not_nil == 1 && (rule->act & RULE_ACT_ALLOW_IDENT)) {
// this rule has only 1 argument and should not be emitted
mp_parse_node_t pn = MP_PARSE_NODE_NULL;
for (size_t x = 0; x < i; ++x) {
mp_parse_node_t pn2 = pop_result(&parser);
if (pn2 != MP_PARSE_NODE_NULL) {
pn = pn2;
}
}
push_result_node(&parser, pn);
} else {
// this rule must be emitted
if (rule->act & RULE_ACT_ADD_BLANK) {
// and add an extra blank node at the end (used by the compiler to store data)
push_result_node(&parser, MP_PARSE_NODE_NULL);
i += 1;
}
push_result_rule(&parser, rule_src_line, rule, i);
}
break;
}
default: {
assert((rule->act & RULE_ACT_KIND_MASK) == RULE_ACT_LIST);
// n=2 is: item item*
// n=1 is: item (sep item)*
// n=3 is: item (sep item)* [sep]
bool had_trailing_sep;
if (backtrack) {
list_backtrack:
had_trailing_sep = false;
if (n == 2) {
if (i == 1) {
// fail on item, first time round; propagate backtrack
goto next_rule;
} else {
// fail on item, in later rounds; finish with this rule
backtrack = false;
}
} else {
if (i == 1) {
// fail on item, first time round; propagate backtrack
goto next_rule;
} else if ((i & 1) == 1) {
// fail on item, in later rounds; have eaten tokens so can't backtrack
if (n == 3) {
// list allows trailing separator; finish parsing list
had_trailing_sep = true;
backtrack = false;
} else {
// list doesn't allowing trailing separator; fail
goto syntax_error;
}
} else {
// fail on separator; finish parsing list
backtrack = false;
}
}
} else {
for (;;) {
size_t arg = rule->arg[i & 1 & n];
if ((arg & RULE_ARG_KIND_MASK) == RULE_ARG_TOK) {
if (lex->tok_kind == (arg & RULE_ARG_ARG_MASK)) {
if (i & 1 & n) {
// separators which are tokens are not pushed to result stack
} else {
push_result_token(&parser, rule);
}
mp_lexer_to_next(lex);
// got element of list, so continue parsing list
i += 1;
} else {
// couldn't get element of list
i += 1;
backtrack = true;
goto list_backtrack;
}
} else {
assert((arg & RULE_ARG_KIND_MASK) == RULE_ARG_RULE);
push_rule(&parser, rule_src_line, rule, i + 1); // save this list-rule
push_rule_from_arg(&parser, arg); // push child of list-rule
goto next_rule;
}
}
}
assert(i >= 1);
// compute number of elements in list, result in i
i -= 1;
if ((n & 1) && (rule->arg[1] & RULE_ARG_KIND_MASK) == RULE_ARG_TOK) {
// don't count separators when they are tokens
i = (i + 1) / 2;
}
if (i == 1) {
// list matched single item
if (had_trailing_sep) {
// if there was a trailing separator, make a list of a single item
push_result_rule(&parser, rule_src_line, rule, i);
} else {
// just leave single item on stack (ie don't wrap in a list)
}
} else {
push_result_rule(&parser, rule_src_line, rule, i);
}
break;
}
}
}
#if MICROPY_COMP_CONST
mp_map_deinit(&parser.consts);
#endif
// truncate final chunk and link into chain of chunks
if (parser.cur_chunk != NULL) {
(void)m_renew_maybe(byte, parser.cur_chunk,
sizeof(mp_parse_chunk_t) + parser.cur_chunk->alloc,
sizeof(mp_parse_chunk_t) + parser.cur_chunk->union_.used,
false);
parser.cur_chunk->alloc = parser.cur_chunk->union_.used;
parser.cur_chunk->union_.next = parser.tree.chunk;
parser.tree.chunk = parser.cur_chunk;
}
if (
lex->tok_kind != MP_TOKEN_END // check we are at the end of the token stream
|| parser.result_stack_top == 0 // check that we got a node (can fail on empty input)
) {
syntax_error:;
mp_obj_t exc;
if (lex->tok_kind == MP_TOKEN_INDENT) {
exc = mp_obj_new_exception_msg(&mp_type_IndentationError,
"unexpected indent");
} else if (lex->tok_kind == MP_TOKEN_DEDENT_MISMATCH) {
exc = mp_obj_new_exception_msg(&mp_type_IndentationError,
"unindent does not match any outer indentation level");
} else {
exc = mp_obj_new_exception_msg(&mp_type_SyntaxError,
"invalid syntax");
}
// add traceback to give info about file name and location
// we don't have a 'block' name, so just pass the NULL qstr to indicate this
mp_obj_exception_add_traceback(exc, lex->source_name, lex->tok_line, MP_QSTR_NULL);
nlr_raise(exc);
}
// get the root parse node that we created
assert(parser.result_stack_top == 1);
parser.tree.root = parser.result_stack[0];
// free the memory that we don't need anymore
m_del(rule_stack_t, parser.rule_stack, parser.rule_stack_alloc);
m_del(mp_parse_node_t, parser.result_stack, parser.result_stack_alloc);
// we also free the lexer on behalf of the caller
mp_lexer_free(lex);
return parser.tree;
}
void mp_parse_tree_clear(mp_parse_tree_t *tree) {
mp_parse_chunk_t *chunk = tree->chunk;
while (chunk != NULL) {
mp_parse_chunk_t *next = chunk->union_.next;
m_del(byte, chunk, sizeof(mp_parse_chunk_t) + chunk->alloc);
chunk = next;
}
}
#endif // MICROPY_ENABLE_COMPILER
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