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cpython/Parser/tokenizer.c

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/* Tokenizer implementation */
#include "Python.h"
#include "pgenheaders.h"
#include <ctype.h>
#include <assert.h>
#include "tokenizer.h"
#include "errcode.h"
#include "unicodeobject.h"
#include "bytesobject.h"
#include "fileobject.h"
#include "codecs.h"
#include "abstract.h"
/* Alternate tab spacing */
#define ALTTABSIZE 1
#define is_potential_identifier_start(c) (\
(c >= 'a' && c <= 'z')\
|| (c >= 'A' && c <= 'Z')\
|| c == '_'\
|| (c >= 128))
#define is_potential_identifier_char(c) (\
(c >= 'a' && c <= 'z')\
|| (c >= 'A' && c <= 'Z')\
|| (c >= '0' && c <= '9')\
|| c == '_'\
|| (c >= 128))
extern char *PyOS_Readline(FILE *, FILE *, const char *);
/* Return malloc'ed string including trailing \n;
empty malloc'ed string for EOF;
NULL if interrupted */
/* Don't ever change this -- it would break the portability of Python code */
#define TABSIZE 8
/* Forward */
static struct tok_state *tok_new(void);
static int tok_nextc(struct tok_state *tok);
static void tok_backup(struct tok_state *tok, int c);
/* Spaces in this constant are treated as "zero or more spaces or tabs" when
tokenizing. */
static const char* type_comment_prefix = "# type: ";
/* Create and initialize a new tok_state structure */
static struct tok_state *
tok_new(void)
{
struct tok_state *tok = (struct tok_state *)PyMem_MALLOC(
sizeof(struct tok_state));
if (tok == NULL)
return NULL;
tok->buf = tok->cur = tok->end = tok->inp = tok->start = NULL;
tok->done = E_OK;
tok->fp = NULL;
tok->input = NULL;
tok->tabsize = TABSIZE;
tok->indent = 0;
tok->indstack[0] = 0;
tok->atbol = 1;
tok->pendin = 0;
tok->prompt = tok->nextprompt = NULL;
tok->lineno = 0;
tok->level = 0;
tok->altindstack[0] = 0;
tok->decoding_state = STATE_INIT;
tok->decoding_erred = 0;
tok->read_coding_spec = 0;
tok->enc = NULL;
tok->encoding = NULL;
tok->cont_line = 0;
tok->filename = NULL;
tok->decoding_readline = NULL;
tok->decoding_buffer = NULL;
tok->type_comments = 0;
return tok;
}
static char *
new_string(const char *s, Py_ssize_t len, struct tok_state *tok)
{
char* result = (char *)PyMem_MALLOC(len + 1);
if (!result) {
tok->done = E_NOMEM;
return NULL;
}
memcpy(result, s, len);
result[len] = '\0';
return result;
}
static char *
error_ret(struct tok_state *tok) /* XXX */
{
tok->decoding_erred = 1;
if (tok->fp != NULL && tok->buf != NULL) /* see PyTokenizer_Free */
PyMem_FREE(tok->buf);
tok->buf = tok->cur = tok->end = tok->inp = tok->start = NULL;
tok->done = E_DECODE;
return NULL; /* as if it were EOF */
}
static const char *
get_normal_name(const char *s) /* for utf-8 and latin-1 */
{
char buf[13];
int i;
for (i = 0; i < 12; i++) {
int c = s[i];
if (c == '\0')
break;
else if (c == '_')
buf[i] = '-';
else
buf[i] = tolower(c);
}
buf[i] = '\0';
if (strcmp(buf, "utf-8") == 0 ||
strncmp(buf, "utf-8-", 6) == 0)
return "utf-8";
else if (strcmp(buf, "latin-1") == 0 ||
strcmp(buf, "iso-8859-1") == 0 ||
strcmp(buf, "iso-latin-1") == 0 ||
strncmp(buf, "latin-1-", 8) == 0 ||
strncmp(buf, "iso-8859-1-", 11) == 0 ||
strncmp(buf, "iso-latin-1-", 12) == 0)
return "iso-8859-1";
else
return s;
}
/* Return the coding spec in S, or NULL if none is found. */
static int
get_coding_spec(const char *s, char **spec, Py_ssize_t size, struct tok_state *tok)
{
Py_ssize_t i;
*spec = NULL;
/* Coding spec must be in a comment, and that comment must be
* the only statement on the source code line. */
for (i = 0; i < size - 6; i++) {
if (s[i] == '#')
break;
if (s[i] != ' ' && s[i] != '\t' && s[i] != '\014')
return 1;
}
for (; i < size - 6; i++) { /* XXX inefficient search */
const char* t = s + i;
if (strncmp(t, "coding", 6) == 0) {
const char* begin = NULL;
t += 6;
if (t[0] != ':' && t[0] != '=')
continue;
do {
t++;
} while (t[0] == '\x20' || t[0] == '\t');
begin = t;
while (Py_ISALNUM(t[0]) ||
t[0] == '-' || t[0] == '_' || t[0] == '.')
t++;
if (begin < t) {
char* r = new_string(begin, t - begin, tok);
const char* q;
if (!r)
return 0;
q = get_normal_name(r);
if (r != q) {
PyMem_FREE(r);
r = new_string(q, strlen(q), tok);
if (!r)
return 0;
}
*spec = r;
break;
}
}
}
return 1;
}
/* Check whether the line contains a coding spec. If it does,
invoke the set_readline function for the new encoding.
This function receives the tok_state and the new encoding.
Return 1 on success, 0 on failure. */
static int
check_coding_spec(const char* line, Py_ssize_t size, struct tok_state *tok,
int set_readline(struct tok_state *, const char *))
{
char *cs;
int r = 1;
if (tok->cont_line) {
/* It's a continuation line, so it can't be a coding spec. */
tok->read_coding_spec = 1;
return 1;
}
if (!get_coding_spec(line, &cs, size, tok))
return 0;
if (!cs) {
Py_ssize_t i;
for (i = 0; i < size; i++) {
if (line[i] == '#' || line[i] == '\n' || line[i] == '\r')
break;
if (line[i] != ' ' && line[i] != '\t' && line[i] != '\014') {
/* Stop checking coding spec after a line containing
* anything except a comment. */
tok->read_coding_spec = 1;
break;
}
}
return 1;
}
tok->read_coding_spec = 1;
if (tok->encoding == NULL) {
assert(tok->decoding_state == STATE_RAW);
if (strcmp(cs, "utf-8") == 0) {
tok->encoding = cs;
} else {
r = set_readline(tok, cs);
if (r) {
tok->encoding = cs;
tok->decoding_state = STATE_NORMAL;
}
else {
PyErr_Format(PyExc_SyntaxError,
"encoding problem: %s", cs);
PyMem_FREE(cs);
}
}
} else { /* then, compare cs with BOM */
r = (strcmp(tok->encoding, cs) == 0);
if (!r)
PyErr_Format(PyExc_SyntaxError,
"encoding problem: %s with BOM", cs);
PyMem_FREE(cs);
}
return r;
}
/* See whether the file starts with a BOM. If it does,
invoke the set_readline function with the new encoding.
Return 1 on success, 0 on failure. */
static int
check_bom(int get_char(struct tok_state *),
void unget_char(int, struct tok_state *),
int set_readline(struct tok_state *, const char *),
struct tok_state *tok)
{
int ch1, ch2, ch3;
ch1 = get_char(tok);
tok->decoding_state = STATE_RAW;
if (ch1 == EOF) {
return 1;
} else if (ch1 == 0xEF) {
ch2 = get_char(tok);
if (ch2 != 0xBB) {
unget_char(ch2, tok);
unget_char(ch1, tok);
return 1;
}
ch3 = get_char(tok);
if (ch3 != 0xBF) {
unget_char(ch3, tok);
unget_char(ch2, tok);
unget_char(ch1, tok);
return 1;
}
#if 0
/* Disable support for UTF-16 BOMs until a decision
is made whether this needs to be supported. */
} else if (ch1 == 0xFE) {
ch2 = get_char(tok);
if (ch2 != 0xFF) {
unget_char(ch2, tok);
unget_char(ch1, tok);
return 1;
}
if (!set_readline(tok, "utf-16-be"))
return 0;
tok->decoding_state = STATE_NORMAL;
} else if (ch1 == 0xFF) {
ch2 = get_char(tok);
if (ch2 != 0xFE) {
unget_char(ch2, tok);
unget_char(ch1, tok);
return 1;
}
if (!set_readline(tok, "utf-16-le"))
return 0;
tok->decoding_state = STATE_NORMAL;
#endif
} else {
unget_char(ch1, tok);
return 1;
}
if (tok->encoding != NULL)
PyMem_FREE(tok->encoding);
tok->encoding = new_string("utf-8", 5, tok);
if (!tok->encoding)
return 0;
/* No need to set_readline: input is already utf-8 */
return 1;
}
/* Read a line of text from TOK into S, using the stream in TOK.
Return NULL on failure, else S.
On entry, tok->decoding_buffer will be one of:
1) NULL: need to call tok->decoding_readline to get a new line
2) PyUnicodeObject *: decoding_feof has called tok->decoding_readline and
stored the result in tok->decoding_buffer
3) PyByteArrayObject *: previous call to fp_readl did not have enough room
(in the s buffer) to copy entire contents of the line read
by tok->decoding_readline. tok->decoding_buffer has the overflow.
In this case, fp_readl is called in a loop (with an expanded buffer)
until the buffer ends with a '\n' (or until the end of the file is
reached): see tok_nextc and its calls to decoding_fgets.
*/
static char *
fp_readl(char *s, int size, struct tok_state *tok)
{
PyObject* bufobj;
const char *buf;
Py_ssize_t buflen;
/* Ask for one less byte so we can terminate it */
assert(size > 0);
size--;
if (tok->decoding_buffer) {
bufobj = tok->decoding_buffer;
Py_INCREF(bufobj);
}
else
{
bufobj = _PyObject_CallNoArg(tok->decoding_readline);
if (bufobj == NULL)
goto error;
}
if (PyUnicode_CheckExact(bufobj))
{
buf = PyUnicode_AsUTF8AndSize(bufobj, &buflen);
if (buf == NULL) {
goto error;
}
}
else
{
buf = PyByteArray_AsString(bufobj);
if (buf == NULL) {
goto error;
}
buflen = PyByteArray_GET_SIZE(bufobj);
}
Py_XDECREF(tok->decoding_buffer);
if (buflen > size) {
/* Too many chars, the rest goes into tok->decoding_buffer */
tok->decoding_buffer = PyByteArray_FromStringAndSize(buf+size,
buflen-size);
if (tok->decoding_buffer == NULL)
goto error;
buflen = size;
}
else
tok->decoding_buffer = NULL;
memcpy(s, buf, buflen);
s[buflen] = '\0';
if (buflen == 0) /* EOF */
s = NULL;
Py_DECREF(bufobj);
return s;
error:
Py_XDECREF(bufobj);
return error_ret(tok);
}
/* Set the readline function for TOK to a StreamReader's
readline function. The StreamReader is named ENC.
This function is called from check_bom and check_coding_spec.
ENC is usually identical to the future value of tok->encoding,
except for the (currently unsupported) case of UTF-16.
Return 1 on success, 0 on failure. */
static int
fp_setreadl(struct tok_state *tok, const char* enc)
{
PyObject *readline, *io, *stream;
_Py_IDENTIFIER(open);
_Py_IDENTIFIER(readline);
int fd;
long pos;
fd = fileno(tok->fp);
/* Due to buffering the file offset for fd can be different from the file
* position of tok->fp. If tok->fp was opened in text mode on Windows,
* its file position counts CRLF as one char and can't be directly mapped
* to the file offset for fd. Instead we step back one byte and read to
* the end of line.*/
pos = ftell(tok->fp);
if (pos == -1 ||
lseek(fd, (off_t)(pos > 0 ? pos - 1 : pos), SEEK_SET) == (off_t)-1) {
PyErr_SetFromErrnoWithFilename(PyExc_OSError, NULL);
return 0;
}
io = PyImport_ImportModuleNoBlock("io");
if (io == NULL)
return 0;
stream = _PyObject_CallMethodId(io, &PyId_open, "isisOOO",
fd, "r", -1, enc, Py_None, Py_None, Py_False);
Py_DECREF(io);
if (stream == NULL)
return 0;
readline = _PyObject_GetAttrId(stream, &PyId_readline);
Py_DECREF(stream);
if (readline == NULL)
return 0;
Py_XSETREF(tok->decoding_readline, readline);
if (pos > 0) {
PyObject *bufobj = _PyObject_CallNoArg(readline);
if (bufobj == NULL)
return 0;
Py_DECREF(bufobj);
}
return 1;
}
/* Fetch the next byte from TOK. */
static int fp_getc(struct tok_state *tok) {
return getc(tok->fp);
}
/* Unfetch the last byte back into TOK. */
static void fp_ungetc(int c, struct tok_state *tok) {
ungetc(c, tok->fp);
}
/* Check whether the characters at s start a valid
UTF-8 sequence. Return the number of characters forming
the sequence if yes, 0 if not. */
static int valid_utf8(const unsigned char* s)
{
int expected = 0;
int length;
if (*s < 0x80)
/* single-byte code */
return 1;
if (*s < 0xc0)
/* following byte */
return 0;
if (*s < 0xE0)
expected = 1;
else if (*s < 0xF0)
expected = 2;
else if (*s < 0xF8)
expected = 3;
else
return 0;
length = expected + 1;
for (; expected; expected--)
if (s[expected] < 0x80 || s[expected] >= 0xC0)
return 0;
return length;
}
/* Read a line of input from TOK. Determine encoding
if necessary. */
static char *
decoding_fgets(char *s, int size, struct tok_state *tok)
{
char *line = NULL;
int badchar = 0;
for (;;) {
if (tok->decoding_state == STATE_NORMAL) {
/* We already have a codec associated with
this input. */
line = fp_readl(s, size, tok);
break;
} else if (tok->decoding_state == STATE_RAW) {
/* We want a 'raw' read. */
line = Py_UniversalNewlineFgets(s, size,
tok->fp, NULL);
break;
} else {
/* We have not yet determined the encoding.
If an encoding is found, use the file-pointer
reader functions from now on. */
if (!check_bom(fp_getc, fp_ungetc, fp_setreadl, tok))
return error_ret(tok);
assert(tok->decoding_state != STATE_INIT);
}
}
if (line != NULL && tok->lineno < 2 && !tok->read_coding_spec) {
if (!check_coding_spec(line, strlen(line), tok, fp_setreadl)) {
return error_ret(tok);
}
}
/* The default encoding is UTF-8, so make sure we don't have any
non-UTF-8 sequences in it. */
if (line && !tok->encoding) {
unsigned char *c;
int length;
for (c = (unsigned char *)line; *c; c += length)
if (!(length = valid_utf8(c))) {
badchar = *c;
break;
}
}
if (badchar) {
/* Need to add 1 to the line number, since this line
has not been counted, yet. */
PyErr_Format(PyExc_SyntaxError,
"Non-UTF-8 code starting with '\\x%.2x' "
"in file %U on line %i, "
"but no encoding declared; "
"see http://python.org/dev/peps/pep-0263/ for details",
badchar, tok->filename, tok->lineno + 1);
return error_ret(tok);
}
return line;
}
static int
decoding_feof(struct tok_state *tok)
{
if (tok->decoding_state != STATE_NORMAL) {
return feof(tok->fp);
} else {
PyObject* buf = tok->decoding_buffer;
if (buf == NULL) {
buf = _PyObject_CallNoArg(tok->decoding_readline);
if (buf == NULL) {
error_ret(tok);
return 1;
} else {
tok->decoding_buffer = buf;
}
}
return PyObject_Length(buf) == 0;
}
}
/* 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;
}
/* Return a UTF-8 encoding Python string object from the
C byte string STR, which is encoded with ENC. */
static PyObject *
translate_into_utf8(const char* str, const char* enc) {
PyObject *utf8;
PyObject* buf = PyUnicode_Decode(str, strlen(str), enc, NULL);
if (buf == NULL)
return NULL;
utf8 = PyUnicode_AsUTF8String(buf);
Py_DECREF(buf);
return utf8;
}
static char *
translate_newlines(const char *s, int exec_input, struct tok_state *tok) {
int skip_next_lf = 0;
size_t needed_length = strlen(s) + 2, final_length;
char *buf, *current;
char c = '\0';
buf = PyMem_MALLOC(needed_length);
if (buf == NULL) {
tok->done = E_NOMEM;
return NULL;
}
for (current = buf; *s; s++, current++) {
c = *s;
if (skip_next_lf) {
skip_next_lf = 0;
if (c == '\n') {
c = *++s;
if (!c)
break;
}
}
if (c == '\r') {
skip_next_lf = 1;
c = '\n';
}
*current = c;
}
/* If this is exec input, add a newline to the end of the string if
there isn't one already. */
if (exec_input && c != '\n') {
*current = '\n';
current++;
}
*current = '\0';
final_length = current - buf + 1;
if (final_length < needed_length && final_length)
/* should never fail */
buf = PyMem_REALLOC(buf, final_length);
return buf;
}
/* Decode a byte string STR for use as the buffer of TOK.
Look for encoding declarations inside STR, and record them
inside TOK. */
static const char *
decode_str(const char *input, int single, struct tok_state *tok)
{
PyObject* utf8 = NULL;
const char *str;
const char *s;
const char *newl[2] = {NULL, NULL};
int lineno = 0;
tok->input = str = translate_newlines(input, single, tok);
if (str == NULL)
return NULL;
tok->enc = NULL;
tok->str = str;
if (!check_bom(buf_getc, buf_ungetc, buf_setreadl, tok))
return error_ret(tok);
str = tok->str; /* string after BOM if any */
assert(str);
if (tok->enc != NULL) {
utf8 = translate_into_utf8(str, tok->enc);
if (utf8 == NULL)
return 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 (!check_coding_spec(str, newl[0] - str, tok, buf_setreadl))
return error_ret(tok);
if (tok->enc == NULL && !tok->read_coding_spec && newl[1]) {
if (!check_coding_spec(newl[0]+1, newl[1] - newl[0],
tok, buf_setreadl))
return error_ret(tok);
}
}
if (tok->enc != NULL) {
assert(utf8 == NULL);
utf8 = translate_into_utf8(str, tok->enc);
if (utf8 == NULL)
return 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)
{
struct tok_state *tok = tok_new();
if (tok == NULL)
return NULL;
str = decode_str(str, exec_input, tok);
if (str == NULL) {
PyTokenizer_Free(tok);
return NULL;
}
/* XXX: constify members. */
tok->buf = tok->cur = tok->end = tok->inp = (char*)str;
return tok;
}
struct tok_state *
PyTokenizer_FromUTF8(const char *str, int exec_input)
{
struct tok_state *tok = tok_new();
if (tok == NULL)
return NULL;
tok->input = str = translate_newlines(str, exec_input, tok);
if (str == NULL) {
PyTokenizer_Free(tok);
return NULL;
}
tok->decoding_state = STATE_RAW;
tok->read_coding_spec = 1;
tok->enc = NULL;
tok->str = str;
tok->encoding = (char *)PyMem_MALLOC(6);
if (!tok->encoding) {
PyTokenizer_Free(tok);
return NULL;
}
strcpy(tok->encoding, "utf-8");
/* XXX: constify members. */
tok->buf = tok->cur = tok->end = tok->inp = (char*)str;
return tok;
}
/* Set up tokenizer for file */
struct tok_state *
PyTokenizer_FromFile(FILE *fp, const char* enc,
const char *ps1, const char *ps2)
{
struct tok_state *tok = tok_new();
if (tok == NULL)
return NULL;
if ((tok->buf = (char *)PyMem_MALLOC(BUFSIZ)) == NULL) {
PyTokenizer_Free(tok);
return NULL;
}
tok->cur = tok->inp = tok->buf;
tok->end = tok->buf + BUFSIZ;
tok->fp = fp;
tok->prompt = ps1;
tok->nextprompt = ps2;
if (enc != NULL) {
/* Must copy encoding declaration since it
gets copied into the parse tree. */
tok->encoding = PyMem_MALLOC(strlen(enc)+1);
if (!tok->encoding) {
PyTokenizer_Free(tok);
return NULL;
}
strcpy(tok->encoding, enc);
tok->decoding_state = STATE_NORMAL;
}
return tok;
}
/* Free a tok_state structure */
void
PyTokenizer_Free(struct tok_state *tok)
{
if (tok->encoding != NULL)
PyMem_FREE(tok->encoding);
Py_XDECREF(tok->decoding_readline);
Py_XDECREF(tok->decoding_buffer);
Py_XDECREF(tok->filename);
if (tok->fp != NULL && tok->buf != NULL)
PyMem_FREE(tok->buf);
if (tok->input)
PyMem_FREE((char *)tok->input);
PyMem_FREE(tok);
}
/* Get next char, updating state; error code goes into tok->done */
static int
tok_nextc(struct tok_state *tok)
{
for (;;) {
if (tok->cur != tok->inp) {
return Py_CHARMASK(*tok->cur++); /* Fast path */
}
if (tok->done != E_OK)
return EOF;
if (tok->fp == NULL) {
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 EOF;
}
}
if (tok->start == NULL)
tok->buf = tok->cur;
tok->line_start = tok->cur;
tok->lineno++;
tok->inp = end;
return Py_CHARMASK(*tok->cur++);
}
if (tok->prompt != NULL) {
char *newtok = PyOS_Readline(stdin, stdout, tok->prompt);
if (newtok != NULL) {
char *translated = translate_newlines(newtok, 0, tok);
PyMem_FREE(newtok);
if (translated == NULL)
return EOF;
newtok = translated;
}
if (tok->encoding && newtok && *newtok) {
/* Recode to UTF-8 */
Py_ssize_t buflen;
const char* buf;
PyObject *u = translate_into_utf8(newtok, tok->encoding);
PyMem_FREE(newtok);
if (!u) {
tok->done = E_DECODE;
return EOF;
}
buflen = PyBytes_GET_SIZE(u);
buf = PyBytes_AS_STRING(u);
newtok = PyMem_MALLOC(buflen+1);
if (newtok == NULL) {
Py_DECREF(u);
tok->done = E_NOMEM;
return EOF;
}
strcpy(newtok, buf);
Py_DECREF(u);
}
if (tok->nextprompt != NULL)
tok->prompt = tok->nextprompt;
if (newtok == NULL)
tok->done = E_INTR;
else if (*newtok == '\0') {
PyMem_FREE(newtok);
tok->done = E_EOF;
}
else if (tok->start != NULL) {
size_t start = tok->start - tok->buf;
size_t oldlen = tok->cur - tok->buf;
size_t newlen = oldlen + strlen(newtok);
char *buf = tok->buf;
buf = (char *)PyMem_REALLOC(buf, newlen+1);
tok->lineno++;
if (buf == NULL) {
PyMem_FREE(tok->buf);
tok->buf = NULL;
PyMem_FREE(newtok);
tok->done = E_NOMEM;
return EOF;
}
tok->buf = buf;
tok->cur = tok->buf + oldlen;
tok->line_start = tok->cur;
strcpy(tok->buf + oldlen, newtok);
PyMem_FREE(newtok);
tok->inp = tok->buf + newlen;
tok->end = tok->inp + 1;
tok->start = tok->buf + start;
}
else {
tok->lineno++;
if (tok->buf != NULL)
PyMem_FREE(tok->buf);
tok->buf = newtok;
tok->cur = tok->buf;
tok->line_start = tok->buf;
tok->inp = strchr(tok->buf, '\0');
tok->end = tok->inp + 1;
}
}
else {
int done = 0;
Py_ssize_t cur = 0;
char *pt;
if (tok->start == NULL) {
if (tok->buf == NULL) {
tok->buf = (char *)
PyMem_MALLOC(BUFSIZ);
if (tok->buf == NULL) {
tok->done = E_NOMEM;
return EOF;
}
tok->end = tok->buf + BUFSIZ;
}
if (decoding_fgets(tok->buf, (int)(tok->end - tok->buf),
tok) == NULL) {
if (!tok->decoding_erred)
tok->done = E_EOF;
done = 1;
}
else {
tok->done = E_OK;
tok->inp = strchr(tok->buf, '\0');
done = tok->inp == tok->buf || tok->inp[-1] == '\n';
}
}
else {
cur = tok->cur - tok->buf;
if (decoding_feof(tok)) {
tok->done = E_EOF;
done = 1;
}
else
tok->done = E_OK;
}
tok->lineno++;
/* Read until '\n' or EOF */
while (!done) {
Py_ssize_t curstart = tok->start == NULL ? -1 :
tok->start - tok->buf;
Py_ssize_t curvalid = tok->inp - tok->buf;
Py_ssize_t newsize = curvalid + BUFSIZ;
char *newbuf = tok->buf;
newbuf = (char *)PyMem_REALLOC(newbuf,
newsize);
if (newbuf == NULL) {
tok->done = E_NOMEM;
tok->cur = tok->inp;
return EOF;
}
tok->buf = newbuf;
tok->cur = tok->buf + cur;
tok->line_start = tok->cur;
tok->inp = tok->buf + curvalid;
tok->end = tok->buf + newsize;
tok->start = curstart < 0 ? NULL :
tok->buf + curstart;
if (decoding_fgets(tok->inp,
(int)(tok->end - tok->inp),
tok) == NULL) {
/* Break out early on decoding
errors, as tok->buf will be NULL
*/
if (tok->decoding_erred)
return EOF;
/* Last line does not end in \n,
fake one */
strcpy(tok->inp, "\n");
}
tok->inp = strchr(tok->inp, '\0');
done = tok->inp[-1] == '\n';
}
if (tok->buf != NULL) {
tok->cur = tok->buf + cur;
tok->line_start = tok->cur;
/* replace "\r\n" with "\n" */
/* For Mac leave the \r, giving a syntax error */
pt = tok->inp - 2;
if (pt >= tok->buf && *pt == '\r') {
*pt++ = '\n';
*pt = '\0';
tok->inp = pt;
}
}
}
if (tok->done != E_OK) {
if (tok->prompt != NULL)
PySys_WriteStderr("\n");
tok->cur = tok->inp;
return EOF;
}
}
/*NOTREACHED*/
}
/* Back-up one character */
static void
tok_backup(struct tok_state *tok, int c)
{
if (c != EOF) {
if (--tok->cur < tok->buf)
Py_FatalError("tok_backup: beginning of buffer");
if (*tok->cur != c)
*tok->cur = c;
}
}
static int
syntaxerror(struct tok_state *tok, const char *format, ...)
{
va_list vargs;
#ifdef HAVE_STDARG_PROTOTYPES
va_start(vargs, format);
#else
va_start(vargs);
#endif
PyErr_FormatV(PyExc_SyntaxError, format, vargs);
va_end(vargs);
PyErr_SyntaxLocationObject(tok->filename,
tok->lineno,
(int)(tok->cur - tok->line_start));
tok->done = E_ERROR;
return ERRORTOKEN;
}
static int
indenterror(struct tok_state *tok)
{
tok->done = E_TABSPACE;
tok->cur = tok->inp;
return ERRORTOKEN;
}
/* Verify that the identifier follows PEP 3131.
All identifier strings are guaranteed to be "ready" unicode objects.
*/
static int
verify_identifier(struct tok_state *tok)
{
PyObject *s;
int result;
if (tok->decoding_erred)
return 0;
s = PyUnicode_DecodeUTF8(tok->start, tok->cur - tok->start, NULL);
if (s == NULL) {
if (PyErr_ExceptionMatches(PyExc_UnicodeDecodeError)) {
PyErr_Clear();
tok->done = E_IDENTIFIER;
} else {
tok->done = E_ERROR;
}
return 0;
}
result = PyUnicode_IsIdentifier(s);
Py_DECREF(s);
if (result == 0)
tok->done = E_IDENTIFIER;
return result;
}
static int
tok_decimal_tail(struct tok_state *tok)
{
int c;
while (1) {
do {
c = tok_nextc(tok);
} while (isdigit(c));
if (c != '_') {
break;
}
c = tok_nextc(tok);
if (!isdigit(c)) {
tok_backup(tok, c);
syntaxerror(tok, "invalid decimal literal");
return 0;
}
}
return c;
}
/* Get next token, after space stripping etc. */
static int
tok_get(struct tok_state *tok, char **p_start, char **p_end)
{
int c;
int blankline, nonascii;
*p_start = *p_end = NULL;
nextline:
tok->start = NULL;
blankline = 0;
/* Get indentation level */
if (tok->atbol) {
int col = 0;
int altcol = 0;
tok->atbol = 0;
for (;;) {
c = tok_nextc(tok);
if (c == ' ') {
col++, altcol++;
}
else if (c == '\t') {
col = (col / tok->tabsize + 1) * tok->tabsize;
altcol = (altcol / ALTTABSIZE + 1) * ALTTABSIZE;
}
else if (c == '\014') {/* Control-L (formfeed) */
col = altcol = 0; /* For Emacs users */
}
else {
break;
}
}
tok_backup(tok, c);
if (c == '#' || c == '\n') {
/* Lines with only whitespace and/or comments
shouldn't affect the indentation and are
not passed to the parser as NEWLINE tokens,
except *totally* empty lines in interactive
mode, which signal the end of a command group. */
if (col == 0 && c == '\n' && tok->prompt != NULL) {
blankline = 0; /* Let it through */
}
else {
blankline = 1; /* Ignore completely */
}
/* We can't jump back right here since we still
may need to skip to the end of a comment */
}
if (!blankline && tok->level == 0) {
if (col == tok->indstack[tok->indent]) {
/* No change */
if (altcol != tok->altindstack[tok->indent]) {
return indenterror(tok);
}
}
else if (col > tok->indstack[tok->indent]) {
/* Indent -- always one */
if (tok->indent+1 >= MAXINDENT) {
tok->done = E_TOODEEP;
tok->cur = tok->inp;
return ERRORTOKEN;
}
if (altcol <= tok->altindstack[tok->indent]) {
return indenterror(tok);
}
tok->pendin++;
tok->indstack[++tok->indent] = col;
tok->altindstack[tok->indent] = altcol;
}
else /* col < tok->indstack[tok->indent] */ {
/* Dedent -- any number, must be consistent */
while (tok->indent > 0 &&
col < tok->indstack[tok->indent]) {
tok->pendin--;
tok->indent--;
}
if (col != tok->indstack[tok->indent]) {
tok->done = E_DEDENT;
tok->cur = tok->inp;
return ERRORTOKEN;
}
if (altcol != tok->altindstack[tok->indent]) {
return indenterror(tok);
}
}
}
}
tok->start = tok->cur;
/* Return pending indents/dedents */
if (tok->pendin != 0) {
if (tok->pendin < 0) {
tok->pendin++;
return DEDENT;
}
else {
tok->pendin--;
return INDENT;
}
}
again:
tok->start = NULL;
/* Skip spaces */
do {
c = tok_nextc(tok);
} while (c == ' ' || c == '\t' || c == '\014');
/* Set start of current token */
tok->start = tok->cur - 1;
/* Skip comment, unless it's a type comment */
if (c == '#') {
const char *prefix, *p, *type_start;
while (c != EOF && c != '\n') {
c = tok_nextc(tok);
}
if (tok->type_comments) {
p = tok->start;
prefix = type_comment_prefix;
while (*prefix && p < tok->cur) {
if (*prefix == ' ') {
while (*p == ' ' || *p == '\t') {
p++;
}
} else if (*prefix == *p) {
p++;
} else {
break;
}
prefix++;
}
/* This is a type comment if we matched all of type_comment_prefix. */
if (!*prefix) {
int is_type_ignore = 1;
tok_backup(tok, c); /* don't eat the newline or EOF */
type_start = p;
is_type_ignore = tok->cur >= p + 6 && memcmp(p, "ignore", 6) == 0;
p += 6;
while (is_type_ignore && p < tok->cur) {
if (*p == '#')
break;
is_type_ignore = is_type_ignore && (*p == ' ' || *p == '\t');
p++;
}
if (is_type_ignore) {
/* If this type ignore is the only thing on the line, consume the newline also. */
if (blankline) {
tok_nextc(tok);
tok->atbol = 1;
}
return TYPE_IGNORE;
} else {
*p_start = (char *) type_start; /* after type_comment_prefix */
*p_end = tok->cur;
return TYPE_COMMENT;
}
}
}
}
/* Check for EOF and errors now */
if (c == EOF) {
return tok->done == E_EOF ? ENDMARKER : ERRORTOKEN;
}
/* Identifier (most frequent token!) */
nonascii = 0;
if (is_potential_identifier_start(c)) {
/* Process the various legal combinations of b"", r"", u"", and f"". */
int saw_b = 0, saw_r = 0, saw_u = 0, saw_f = 0;
while (1) {
if (!(saw_b || saw_u || saw_f) && (c == 'b' || c == 'B'))
saw_b = 1;
/* Since this is a backwards compatibility support literal we don't
want to support it in arbitrary order like byte literals. */
else if (!(saw_b || saw_u || saw_r || saw_f)
&& (c == 'u'|| c == 'U')) {
saw_u = 1;
}
/* ur"" and ru"" are not supported */
else if (!(saw_r || saw_u) && (c == 'r' || c == 'R')) {
saw_r = 1;
}
else if (!(saw_f || saw_b || saw_u) && (c == 'f' || c == 'F')) {
saw_f = 1;
}
else {
break;
}
c = tok_nextc(tok);
if (c == '"' || c == '\'') {
goto letter_quote;
}
}
while (is_potential_identifier_char(c)) {
if (c >= 128) {
nonascii = 1;
}
c = tok_nextc(tok);
}
tok_backup(tok, c);
if (nonascii && !verify_identifier(tok)) {
return ERRORTOKEN;
}
*p_start = tok->start;
*p_end = tok->cur;
return NAME;
}
/* Newline */
if (c == '\n') {
tok->atbol = 1;
if (blankline || tok->level > 0) {
goto nextline;
}
*p_start = tok->start;
*p_end = tok->cur - 1; /* Leave '\n' out of the string */
tok->cont_line = 0;
return NEWLINE;
}
/* Period or number starting with period? */
if (c == '.') {
c = tok_nextc(tok);
if (isdigit(c)) {
goto fraction;
} else if (c == '.') {
c = tok_nextc(tok);
if (c == '.') {
*p_start = tok->start;
*p_end = tok->cur;
return ELLIPSIS;
}
else {
tok_backup(tok, c);
}
tok_backup(tok, '.');
}
else {
tok_backup(tok, c);
}
*p_start = tok->start;
*p_end = tok->cur;
return DOT;
}
/* Number */
if (isdigit(c)) {
if (c == '0') {
/* Hex, octal or binary -- maybe. */
c = tok_nextc(tok);
if (c == 'x' || c == 'X') {
/* Hex */
c = tok_nextc(tok);
do {
if (c == '_') {
c = tok_nextc(tok);
}
if (!isxdigit(c)) {
tok_backup(tok, c);
return syntaxerror(tok, "invalid hexadecimal literal");
}
do {
c = tok_nextc(tok);
} while (isxdigit(c));
} while (c == '_');
}
else if (c == 'o' || c == 'O') {
/* Octal */
c = tok_nextc(tok);
do {
if (c == '_') {
c = tok_nextc(tok);
}
if (c < '0' || c >= '8') {
tok_backup(tok, c);
if (isdigit(c)) {
return syntaxerror(tok,
"invalid digit '%c' in octal literal", c);
}
else {
return syntaxerror(tok, "invalid octal literal");
}
}
do {
c = tok_nextc(tok);
} while ('0' <= c && c < '8');
} while (c == '_');
if (isdigit(c)) {
return syntaxerror(tok,
"invalid digit '%c' in octal literal", c);
}
}
else if (c == 'b' || c == 'B') {
/* Binary */
c = tok_nextc(tok);
do {
if (c == '_') {
c = tok_nextc(tok);
}
if (c != '0' && c != '1') {
tok_backup(tok, c);
if (isdigit(c)) {
return syntaxerror(tok,
"invalid digit '%c' in binary literal", c);
}
else {
return syntaxerror(tok, "invalid binary literal");
}
}
do {
c = tok_nextc(tok);
} while (c == '0' || c == '1');
} while (c == '_');
if (isdigit(c)) {
return syntaxerror(tok,
"invalid digit '%c' in binary literal", c);
}
}
else {
int nonzero = 0;
/* maybe old-style octal; c is first char of it */
/* in any case, allow '0' as a literal */
while (1) {
if (c == '_') {
c = tok_nextc(tok);
if (!isdigit(c)) {
tok_backup(tok, c);
return syntaxerror(tok, "invalid decimal literal");
}
}
if (c != '0') {
break;
}
c = tok_nextc(tok);
}
if (isdigit(c)) {
nonzero = 1;
c = tok_decimal_tail(tok);
if (c == 0) {
return ERRORTOKEN;
}
}
if (c == '.') {
c = tok_nextc(tok);
goto fraction;
}
else if (c == 'e' || c == 'E') {
goto exponent;
}
else if (c == 'j' || c == 'J') {
goto imaginary;
}
else if (nonzero) {
/* Old-style octal: now disallowed. */
tok_backup(tok, c);
return syntaxerror(tok,
"leading zeros in decimal integer "
"literals are not permitted; "
"use an 0o prefix for octal integers");
}
}
}
else {
/* Decimal */
c = tok_decimal_tail(tok);
if (c == 0) {
return ERRORTOKEN;
}
{
/* Accept floating point numbers. */
if (c == '.') {
c = tok_nextc(tok);
fraction:
/* Fraction */
if (isdigit(c)) {
c = tok_decimal_tail(tok);
if (c == 0) {
return ERRORTOKEN;
}
}
}
if (c == 'e' || c == 'E') {
int e;
exponent:
e = c;
/* Exponent part */
c = tok_nextc(tok);
if (c == '+' || c == '-') {
c = tok_nextc(tok);
if (!isdigit(c)) {
tok_backup(tok, c);
return syntaxerror(tok, "invalid decimal literal");
}
} else if (!isdigit(c)) {
tok_backup(tok, c);
tok_backup(tok, e);
*p_start = tok->start;
*p_end = tok->cur;
return NUMBER;
}
c = tok_decimal_tail(tok);
if (c == 0) {
return ERRORTOKEN;
}
}
if (c == 'j' || c == 'J') {
/* Imaginary part */
imaginary:
c = tok_nextc(tok);
}
}
}
tok_backup(tok, c);
*p_start = tok->start;
*p_end = tok->cur;
return NUMBER;
}
letter_quote:
/* String */
if (c == '\'' || c == '"') {
int quote = c;
int quote_size = 1; /* 1 or 3 */
int end_quote_size = 0;
/* Nodes of type STRING, especially multi line strings
must be handled differently in order to get both
the starting line number and the column offset right.
(cf. issue 16806) */
tok->first_lineno = tok->lineno;
tok->multi_line_start = tok->line_start;
/* Find the quote size and start of string */
c = tok_nextc(tok);
if (c == quote) {
c = tok_nextc(tok);
if (c == quote) {
quote_size = 3;
}
else {
end_quote_size = 1; /* empty string found */
}
}
if (c != quote) {
tok_backup(tok, c);
}
/* Get rest of string */
while (end_quote_size != quote_size) {
c = tok_nextc(tok);
if (c == EOF) {
if (quote_size == 3) {
tok->done = E_EOFS;
}
else {
tok->done = E_EOLS;
}
tok->cur = tok->inp;
return ERRORTOKEN;
}
if (quote_size == 1 && c == '\n') {
tok->done = E_EOLS;
tok->cur = tok->inp;
return ERRORTOKEN;
}
if (c == quote) {
end_quote_size += 1;
}
else {
end_quote_size = 0;
if (c == '\\') {
tok_nextc(tok); /* skip escaped char */
}
}
}
*p_start = tok->start;
*p_end = tok->cur;
return STRING;
}
/* Line continuation */
if (c == '\\') {
c = tok_nextc(tok);
if (c != '\n') {
tok->done = E_LINECONT;
tok->cur = tok->inp;
return ERRORTOKEN;
}
tok->cont_line = 1;
goto again; /* Read next line */
}
/* Check for two-character token */
{
int c2 = tok_nextc(tok);
int token = PyToken_TwoChars(c, c2);
if (token != OP) {
int c3 = tok_nextc(tok);
int token3 = PyToken_ThreeChars(c, c2, c3);
if (token3 != OP) {
token = token3;
}
else {
tok_backup(tok, c3);
}
*p_start = tok->start;
*p_end = tok->cur;
return token;
}
tok_backup(tok, c2);
}
/* Keep track of parentheses nesting level */
switch (c) {
case '(':
case '[':
case '{':
if (tok->level >= MAXLEVEL) {
return syntaxerror(tok, "too many nested parentheses");
}
tok->parenstack[tok->level] = c;
tok->parenlinenostack[tok->level] = tok->lineno;
tok->level++;
break;
case ')':
case ']':
case '}':
if (!tok->level) {
return syntaxerror(tok, "unmatched '%c'", c);
}
tok->level--;
int opening = tok->parenstack[tok->level];
if (!((opening == '(' && c == ')') ||
(opening == '[' && c == ']') ||
(opening == '{' && c == '}')))
{
if (tok->parenlinenostack[tok->level] != tok->lineno) {
return syntaxerror(tok,
"closing parenthesis '%c' does not match "
"opening parenthesis '%c' on line %d",
c, opening, tok->parenlinenostack[tok->level]);
}
else {
return syntaxerror(tok,
"closing parenthesis '%c' does not match "
"opening parenthesis '%c'",
c, opening);
}
}
break;
}
/* Punctuation character */
*p_start = tok->start;
*p_end = tok->cur;
return PyToken_OneChar(c);
}
int
PyTokenizer_Get(struct tok_state *tok, char **p_start, char **p_end)
{
int result = tok_get(tok, p_start, p_end);
if (tok->decoding_erred) {
result = ERRORTOKEN;
tok->done = E_DECODE;
}
return result;
}
/* Get the encoding of a Python file. Check for the coding cookie and check if
the file starts with a BOM.
PyTokenizer_FindEncodingFilename() returns NULL when it can't find the
encoding in the first or second line of the file (in which case the encoding
should be assumed to be UTF-8).
The char* returned is malloc'ed via PyMem_MALLOC() and thus must be freed
by the caller. */
char *
PyTokenizer_FindEncodingFilename(int fd, PyObject *filename)
{
struct tok_state *tok;
FILE *fp;
char *p_start =NULL , *p_end =NULL , *encoding = NULL;
fd = _Py_dup(fd);
if (fd < 0) {
return NULL;
}
fp = fdopen(fd, "r");
if (fp == NULL) {
return NULL;
}
tok = PyTokenizer_FromFile(fp, NULL, NULL, NULL);
if (tok == NULL) {
fclose(fp);
return NULL;
}
if (filename != NULL) {
Py_INCREF(filename);
tok->filename = filename;
}
else {
tok->filename = PyUnicode_FromString("<string>");
if (tok->filename == NULL) {
fclose(fp);
PyTokenizer_Free(tok);
return encoding;
}
}
while (tok->lineno < 2 && tok->done == E_OK) {
PyTokenizer_Get(tok, &p_start, &p_end);
}
fclose(fp);
if (tok->encoding) {
encoding = (char *)PyMem_MALLOC(strlen(tok->encoding) + 1);
if (encoding)
strcpy(encoding, tok->encoding);
}
PyTokenizer_Free(tok);
return encoding;
}
char *
PyTokenizer_FindEncoding(int fd)
{
return PyTokenizer_FindEncodingFilename(fd, NULL);
}
#ifdef Py_DEBUG
void
tok_dump(int type, char *start, char *end)
{
printf("%s", _PyParser_TokenNames[type]);
if (type == NAME || type == NUMBER || type == STRING || type == OP)
printf("(%.*s)", (int)(end - start), start);
}
#endif
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