cpython/Parser/tokenizer/string_tokenizer.c

130 lines
3.6 KiB
C

#include "Python.h"
#include "errcode.h"
#include "helpers.h"
#include "../lexer/state.h"
static int
tok_underflow_string(struct tok_state *tok) {
char *end = strchr(tok->inp, '\n');
if (end != NULL) {
end++;
}
else {
end = strchr(tok->inp, '\0');
if (end == tok->inp) {
tok->done = E_EOF;
return 0;
}
}
if (tok->start == NULL) {
tok->buf = tok->cur;
}
tok->line_start = tok->cur;
ADVANCE_LINENO();
tok->inp = end;
return 1;
}
/* Fetch a byte from TOK, using the string buffer. */
static int
buf_getc(struct tok_state *tok) {
return Py_CHARMASK(*tok->str++);
}
/* Unfetch a byte from TOK, using the string buffer. */
static void
buf_ungetc(int c, struct tok_state *tok) {
tok->str--;
assert(Py_CHARMASK(*tok->str) == c); /* tok->cur may point to read-only segment */
}
/* Set the readline function for TOK to ENC. For the string-based
tokenizer, this means to just record the encoding. */
static int
buf_setreadl(struct tok_state *tok, const char* enc) {
tok->enc = enc;
return 1;
}
/* Decode a byte string STR for use as the buffer of TOK.
Look for encoding declarations inside STR, and record them
inside TOK. */
static char *
decode_str(const char *input, int single, struct tok_state *tok, int preserve_crlf)
{
PyObject* utf8 = NULL;
char *str;
const char *s;
const char *newl[2] = {NULL, NULL};
int lineno = 0;
tok->input = str = _PyTokenizer_translate_newlines(input, single, preserve_crlf, tok);
if (str == NULL)
return NULL;
tok->enc = NULL;
tok->str = str;
if (!_PyTokenizer_check_bom(buf_getc, buf_ungetc, buf_setreadl, tok))
return _PyTokenizer_error_ret(tok);
str = tok->str; /* string after BOM if any */
assert(str);
if (tok->enc != NULL) {
utf8 = _PyTokenizer_translate_into_utf8(str, tok->enc);
if (utf8 == NULL)
return _PyTokenizer_error_ret(tok);
str = PyBytes_AsString(utf8);
}
for (s = str;; s++) {
if (*s == '\0') break;
else if (*s == '\n') {
assert(lineno < 2);
newl[lineno] = s;
lineno++;
if (lineno == 2) break;
}
}
tok->enc = NULL;
/* need to check line 1 and 2 separately since check_coding_spec
assumes a single line as input */
if (newl[0]) {
if (!_PyTokenizer_check_coding_spec(str, newl[0] - str, tok, buf_setreadl)) {
return NULL;
}
if (tok->enc == NULL && tok->decoding_state != STATE_NORMAL && newl[1]) {
if (!_PyTokenizer_check_coding_spec(newl[0]+1, newl[1] - newl[0],
tok, buf_setreadl))
return NULL;
}
}
if (tok->enc != NULL) {
assert(utf8 == NULL);
utf8 = _PyTokenizer_translate_into_utf8(str, tok->enc);
if (utf8 == NULL)
return _PyTokenizer_error_ret(tok);
str = PyBytes_AS_STRING(utf8);
}
assert(tok->decoding_buffer == NULL);
tok->decoding_buffer = utf8; /* CAUTION */
return str;
}
/* Set up tokenizer for string */
struct tok_state *
_PyTokenizer_FromString(const char *str, int exec_input, int preserve_crlf)
{
struct tok_state *tok = _PyTokenizer_tok_new();
char *decoded;
if (tok == NULL)
return NULL;
decoded = decode_str(str, exec_input, tok, preserve_crlf);
if (decoded == NULL) {
_PyTokenizer_Free(tok);
return NULL;
}
tok->buf = tok->cur = tok->inp = decoded;
tok->end = decoded;
tok->underflow = &tok_underflow_string;
return tok;
}