From fe8fb9165c694e77d520c32177216bfe8004892e Mon Sep 17 00:00:00 2001
From: Damien George <damien.p.george@gmail.com>
Date: Thu, 2 Jan 2014 16:36:09 +0000
Subject: [PATCH] py: remove depedence on strcat and stpcpy.
This fixes Issue #29, and means the core is no longer dependent on
string functions, except strlen.
---
py/compile.c | 18 +++++++++++++-----
py/objstr.c | 35 +++++++++++++++++++++++++++--------
2 files changed, 40 insertions(+), 13 deletions(-)
diff --git a/py/compile.c b/py/compile.c
index fe22a9017..b00ab7ef6 100644
--- a/py/compile.c
+++ b/py/compile.c
@@ -1182,13 +1182,18 @@ void do_import_name(compiler_t *comp, mp_parse_node_t pn, qstr *q1, qstr *q2) {
len += strlen(qstr_str(MP_PARSE_NODE_LEAF_ARG(pns->nodes[i])));
}
char *str = m_new(char, len + 1);
+ char *str_dest = str;
str[0] = 0;
for (int i = 0; i < n; i++) {
if (i > 0) {
- strcat(str, ".");
+ *str_dest++ = '.';
}
- strcat(str, qstr_str(MP_PARSE_NODE_LEAF_ARG(pns->nodes[i])));
+ const char *str_src = qstr_str(MP_PARSE_NODE_LEAF_ARG(pns->nodes[i]));
+ size_t str_src_len = strlen(str_src);
+ memcpy(str_dest, str_src, str_src_len);
+ str_dest += str_src_len;
}
+ *str_dest = '\0';
*q2 = qstr_from_str_take(str, len + 1);
EMIT(import_name, *q2);
if (is_as) {
@@ -2124,13 +2129,16 @@ void compile_atom_string(compiler_t *comp, mp_parse_node_struct_t *pns) {
// allocate memory for concatenated string/bytes
char *cat_str = m_new(char, n_bytes + 1);
- cat_str[0] = '\0';
// concatenate string/bytes
+ char *s_dest = cat_str;
for (int i = 0; i < n; i++) {
- const char *str = qstr_str(MP_PARSE_NODE_LEAF_ARG(pns->nodes[i]));
- strcat(cat_str, str);
+ const char *s = qstr_str(MP_PARSE_NODE_LEAF_ARG(pns->nodes[i]));
+ size_t s_len = strlen(s);
+ memcpy(s_dest, s, s_len);
+ s_dest += s_len;
}
+ *s_dest = '\0';
EMIT(load_const_str, qstr_from_str_take(cat_str, n_bytes + 1), string_kind == MP_PARSE_NODE_BYTES);
}
diff --git a/py/objstr.c b/py/objstr.c
index 104a54bb3..48abf4951 100644
--- a/py/objstr.c
+++ b/py/objstr.c
@@ -36,9 +36,13 @@ mp_obj_t str_binary_op(int op, mp_obj_t lhs_in, mp_obj_t rhs_in) {
if (MP_OBJ_IS_TYPE(rhs_in, &str_type)) {
// add 2 strings
const char *rhs_str = qstr_str(((mp_obj_str_t*)rhs_in)->qstr);
- int alloc_len = strlen(lhs_str) + strlen(rhs_str) + 1;
+ size_t lhs_len = strlen(lhs_str);
+ size_t rhs_len = strlen(rhs_str);
+ int alloc_len = lhs_len + rhs_len + 1;
char *val = m_new(char, alloc_len);
- stpcpy(stpcpy(val, lhs_str), rhs_str);
+ memcpy(val, lhs_str, lhs_len);
+ memcpy(val + lhs_len, rhs_str, rhs_len);
+ val[lhs_len + rhs_len] = '\0';
return mp_obj_new_str(qstr_from_str_take(val, alloc_len));
}
break;
@@ -50,9 +54,12 @@ mp_obj_t str_binary_op(int op, mp_obj_t lhs_in, mp_obj_t rhs_in) {
mp_obj_t str_join(mp_obj_t self_in, mp_obj_t arg) {
assert(MP_OBJ_IS_TYPE(self_in, &str_type));
mp_obj_str_t *self = self_in;
- int required_len = strlen(qstr_str(self->qstr));
- // process arg, count required chars
+ // get separation string
+ const char *sep_str = qstr_str(self->qstr);
+ size_t sep_len = strlen(sep_str);
+
+ // process args
uint seq_len;
mp_obj_t *seq_items;
if (MP_OBJ_IS_TYPE(arg, &tuple_type)) {
@@ -62,23 +69,35 @@ mp_obj_t str_join(mp_obj_t self_in, mp_obj_t arg) {
} else {
goto bad_arg;
}
+
+ // count required length
+ int required_len = 0;
for (int i = 0; i < seq_len; i++) {
if (!MP_OBJ_IS_TYPE(seq_items[i], &str_type)) {
goto bad_arg;
}
+ if (i > 0) {
+ required_len += sep_len;
+ }
required_len += strlen(qstr_str(mp_obj_str_get(seq_items[i])));
}
// make joined string
char *joined_str = m_new(char, required_len + 1);
- joined_str[0] = 0;
+ char *s_dest = joined_str;
for (int i = 0; i < seq_len; i++) {
- const char *s2 = qstr_str(mp_obj_str_get(seq_items[i]));
if (i > 0) {
- strcat(joined_str, qstr_str(self->qstr));
+ memcpy(s_dest, sep_str, sep_len);
+ s_dest += sep_len;
}
- strcat(joined_str, s2);
+ const char *s2 = qstr_str(mp_obj_str_get(seq_items[i]));
+ size_t s2_len = strlen(s2);
+ memcpy(s_dest, s2, s2_len);
+ s_dest += s2_len;
}
+ *s_dest = '\0';
+
+ // return joined string
return mp_obj_new_str(qstr_from_str_take(joined_str, required_len + 1));
bad_arg:
--
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