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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"
#ifndef PGEN
#include "unicodeobject.h"
#include "stringobject.h"
#include "fileobject.h"
#include "codecs.h"
#include "abstract.h"
#endif /* PGEN */
#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 *, 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
/* Convert a possibly signed character to a nonnegative int */
/* XXX This assumes characters are 8 bits wide */
#ifdef __CHAR_UNSIGNED__
#define Py_CHARMASK(c) (c)
#else
#define Py_CHARMASK(c) ((c) & 0xff)
#endif
/* 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);
/* Token names */
char *_PyParser_TokenNames[] = {
"ENDMARKER",
"NAME",
"NUMBER",
"STRING",
"NEWLINE",
"INDENT",
"DEDENT",
"LPAR",
"RPAR",
"LSQB",
"RSQB",
"COLON",
"COMMA",
"SEMI",
"PLUS",
"MINUS",
"STAR",
"SLASH",
"VBAR",
"AMPER",
"LESS",
"GREATER",
"EQUAL",
"DOT",
"PERCENT",
"LBRACE",
"RBRACE",
"EQEQUAL",
"NOTEQUAL",
"LESSEQUAL",
"GREATEREQUAL",
"TILDE",
"CIRCUMFLEX",
"LEFTSHIFT",
"RIGHTSHIFT",
"DOUBLESTAR",
"PLUSEQUAL",
"MINEQUAL",
"STAREQUAL",
"SLASHEQUAL",
"PERCENTEQUAL",
"AMPEREQUAL",
"VBAREQUAL",
"CIRCUMFLEXEQUAL",
"LEFTSHIFTEQUAL",
"RIGHTSHIFTEQUAL",
"DOUBLESTAREQUAL",
"DOUBLESLASH",
"DOUBLESLASHEQUAL",
"AT",
"RARROW",
"ELLIPSIS",
/* This table must match the #defines in token.h! */
"OP",
"<ERRORTOKEN>",
"<N_TOKENS>"
};
/* 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->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->filename = NULL;
tok->altwarning = 1;
tok->alterror = 1;
tok->alttabsize = 1;
tok->altindstack[0] = 0;
tok->decoding_state = 0;
tok->decoding_erred = 0;
tok->read_coding_spec = 0;
tok->encoding = NULL;
tok->cont_line = 0;
#ifndef PGEN
tok->decoding_readline = NULL;
tok->decoding_buffer = NULL;
#endif
return tok;
}
#ifdef PGEN
static char *
decoding_fgets(char *s, int size, struct tok_state *tok)
{
return fgets(s, size, tok->fp);
}
static int
decoding_feof(struct tok_state *tok)
{
return feof(tok->fp);
}
static const char *
decode_str(const char *str, struct tok_state *tok)
{
return str;
}
#else /* PGEN */
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 = NULL;
return NULL; /* as if it were EOF */
}
static char *
new_string(const char *s, Py_ssize_t len)
{
char* result = (char *)PyMem_MALLOC(len + 1);
if (result != NULL) {
memcpy(result, s, len);
result[len] = '\0';
}
return result;
}
static char *
get_normal_name(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 char *
get_coding_spec(const char *s, Py_ssize_t size)
{
Py_ssize_t i;
/* 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 NULL;
}
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 (isalnum(Py_CHARMASK(t[0])) ||
t[0] == '-' || t[0] == '_' || t[0] == '.')
t++;
if (begin < t) {
char* r = new_string(begin, t - begin);
char* q = get_normal_name(r);
if (r != q) {
PyMem_FREE(r);
r = new_string(q, strlen(q));
}
return r;
}
}
}
return NULL;
}
/* 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. */
return 1;
cs = get_coding_spec(line, size);
if (cs != NULL) {
tok->read_coding_spec = 1;
if (tok->encoding == NULL) {
assert(tok->decoding_state == 1); /* raw */
if (strcmp(cs, "utf-8") == 0 ||
strcmp(cs, "iso-8859-1") == 0) {
tok->encoding = cs;
} else {
r = set_readline(tok, cs);
if (r) {
tok->encoding = cs;
tok->decoding_state = -1;
}
else
PyMem_FREE(cs);
}
} else { /* then, compare cs with BOM */
r = (strcmp(tok->encoding, cs) == 0);
PyMem_FREE(cs);
}
}
if (!r) {
cs = tok->encoding;
if (!cs)
cs = "with BOM";
PyErr_Format(PyExc_SyntaxError, "encoding problem: %s", 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 ch = get_char(tok);
tok->decoding_state = 1;
if (ch == EOF) {
return 1;
} else if (ch == 0xEF) {
ch = get_char(tok); if (ch != 0xBB) goto NON_BOM;
ch = get_char(tok); if (ch != 0xBF) goto NON_BOM;
#if 0
/* Disable support for UTF-16 BOMs until a decision
is made whether this needs to be supported. */
} else if (ch == 0xFE) {
ch = get_char(tok); if (ch != 0xFF) goto NON_BOM;
if (!set_readline(tok, "utf-16-be")) return 0;
tok->decoding_state = -1;
} else if (ch == 0xFF) {
ch = get_char(tok); if (ch != 0xFE) goto NON_BOM;
if (!set_readline(tok, "utf-16-le")) return 0;
tok->decoding_state = -1;
#endif
} else {
unget_char(ch, tok);
return 1;
}
if (tok->encoding != NULL)
PyMem_FREE(tok->encoding);
tok->encoding = new_string("utf-8", 5); /* resulting is in utf-8 */
return 1;
NON_BOM:
/* any token beginning with '\xEF', '\xFE', '\xFF' is a bad token */
unget_char(0xFF, tok); /* XXX this will cause a syntax error */
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) PyStringObject *: 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 = tok->decoding_buffer;
const char *buf;
Py_ssize_t buflen;
int allocated = 0;
/* Ask for one less byte so we can terminate it */
assert(size > 0);
size--;
if (bufobj == NULL) {
bufobj = PyObject_CallObject(tok->decoding_readline, NULL);
if (bufobj == NULL)
goto error;
allocated = 1;
}
buf = PyUnicode_AsStringAndSize(bufobj, &buflen);
if (buf == NULL) {
goto error;
}
if (buflen > size) {
Py_XDECREF(tok->decoding_buffer);
tok->decoding_buffer = PyBytes_FromStringAndSize(buf+size,
buflen-size);
if (tok->decoding_buffer == NULL)
goto error;
buflen = size;
}
memcpy(s, buf, buflen);
s[buflen] = '\0';
if (buflen == 0) /* EOF */
s = NULL;
if (allocated) {
Py_DECREF(bufobj);
}
return s;
error:
if (allocated) {
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 = NULL, *stream = NULL, *io = NULL;
io = PyImport_ImportModule("io");
if (io == NULL)
goto cleanup;
stream = PyObject_CallMethod(io, "open", "ssis",
tok->filename, "r", -1, enc);
if (stream == NULL)
goto cleanup;
Py_XDECREF(tok->decoding_readline);
readline = PyObject_GetAttrString(stream, "readline");
tok->decoding_readline = readline;
cleanup:
Py_XDECREF(stream);
Py_XDECREF(io);
return readline != NULL;
}
/* 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 < 0) {
/* We already have a codec associated with
this input. */
line = fp_readl(s, size, tok);
break;
} else if (tok->decoding_state > 0) {
/* 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 != 0);
}
}
if (line != NULL && tok->lineno < 2 && !tok->read_coding_spec) {
if (!check_coding_spec(line, strlen(line), tok, fp_setreadl)) {
return error_ret(tok);
}
}
#ifndef PGEN
/* 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) {
char buf[500];
/* Need to add 1 to the line number, since this line
has not been counted, yet. */
sprintf(buf,
"Non-UTF-8 code starting with '\\x%.2x' "
"in file %.200s on line %i, "
"but no encoding declared; "
"see http://python.org/dev/peps/pep-0263/ for details",
badchar, tok->filename, tok->lineno + 1);
PyErr_SetString(PyExc_SyntaxError, buf);
return error_ret(tok);
}
#endif
return line;
}
static int
decoding_feof(struct tok_state *tok)
{
if (tok->decoding_state >= 0) {
return feof(tok->fp);
} else {
PyObject* buf = tok->decoding_buffer;
if (buf == NULL) {
buf = PyObject_CallObject(tok->decoding_readline, NULL);
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;
}
/* 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 *str, struct tok_state *tok)
{
PyObject* utf8 = NULL;
const char *s;
int lineno = 0;
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 = PyString_AsString(utf8);
}
for (s = str;; s++) {
if (*s == '\0') break;
else if (*s == '\n') {
lineno++;
if (lineno == 2) break;
}
}
tok->enc = NULL;
if (!check_coding_spec(str, s - str, tok, buf_setreadl))
return error_ret(tok);
if (tok->enc != NULL) {
assert(utf8 == NULL);
utf8 = translate_into_utf8(str, tok->enc);
if (utf8 == NULL) {
PyErr_Format(PyExc_SyntaxError,
"unknown encoding: %s", tok->enc);
return error_ret(tok);
}
str = PyBytes_AsString(utf8);
}
assert(tok->decoding_buffer == NULL);
tok->decoding_buffer = utf8; /* CAUTION */
return str;
}
#endif /* PGEN */
/* Set up tokenizer for string */
struct tok_state *
PyTokenizer_FromString(const char *str)
{
struct tok_state *tok = tok_new();
if (tok == NULL)
return NULL;
str = (char *)decode_str(str, tok);
if (str == NULL) {
PyTokenizer_Free(tok);
return NULL;
}
/* 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, char* enc, char *ps1, 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 = -1;
}
return tok;
}
/* Free a tok_state structure */
void
PyTokenizer_Free(struct tok_state *tok)
{
if (tok->encoding != NULL)
PyMem_FREE(tok->encoding);
#ifndef PGEN
Py_XDECREF(tok->decoding_readline);
Py_XDECREF(tok->decoding_buffer);
#endif
if (tok->fp != NULL && tok->buf != NULL)
PyMem_FREE(tok->buf);
PyMem_FREE(tok);
}
/* Get next char, updating state; error code goes into tok->done */
static int
tok_nextc(register 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);
#ifndef PGEN
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_Size(u);
buf = PyBytes_AsString(u);
if (!buf) {
Py_DECREF(u);
tok->done = E_DECODE;
return EOF;
}
newtok = PyMem_MALLOC(buflen+1);
strcpy(newtok, buf);
Py_DECREF(u);
}
#endif
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->line_start = tok->buf;
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) {
tok->done = E_EOF;
done = 1;
}
else {
tok->done = E_OK;
tok->inp = strchr(tok->buf, '\0');
done = 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->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(register struct tok_state *tok, register int c)
{
if (c != EOF) {
if (--tok->cur < tok->buf)
Py_FatalError("tok_backup: begin of buffer");
if (*tok->cur != c)
*tok->cur = c;
}
}
/* Return the token corresponding to a single character */
int
PyToken_OneChar(int c)
{
switch (c) {
case '(': return LPAR;
case ')': return RPAR;
case '[': return LSQB;
case ']': return RSQB;
case ':': return COLON;
case ',': return COMMA;
case ';': return SEMI;
case '+': return PLUS;
case '-': return MINUS;
case '*': return STAR;
case '/': return SLASH;
case '|': return VBAR;
case '&': return AMPER;
case '<': return LESS;
case '>': return GREATER;
case '=': return EQUAL;
case '.': return DOT;
case '%': return PERCENT;
case '{': return LBRACE;
case '}': return RBRACE;
case '^': return CIRCUMFLEX;
case '~': return TILDE;
case '@': return AT;
default: return OP;
}
}
int
PyToken_TwoChars(int c1, int c2)
{
switch (c1) {
case '=':
switch (c2) {
case '=': return EQEQUAL;
}
break;
case '!':
switch (c2) {
case '=': return NOTEQUAL;
}
break;
case '<':
switch (c2) {
case '=': return LESSEQUAL;
case '<': return LEFTSHIFT;
}
break;
case '>':
switch (c2) {
case '=': return GREATEREQUAL;
case '>': return RIGHTSHIFT;
}
break;
case '+':
switch (c2) {
case '=': return PLUSEQUAL;
}
break;
case '-':
switch (c2) {
case '=': return MINEQUAL;
case '>': return RARROW;
}
break;
case '*':
switch (c2) {
case '*': return DOUBLESTAR;
case '=': return STAREQUAL;
}
break;
case '/':
switch (c2) {
case '/': return DOUBLESLASH;
case '=': return SLASHEQUAL;
}
break;
case '|':
switch (c2) {
case '=': return VBAREQUAL;
}
break;
case '%':
switch (c2) {
case '=': return PERCENTEQUAL;
}
break;
case '&':
switch (c2) {
case '=': return AMPEREQUAL;
}
break;
case '^':
switch (c2) {
case '=': return CIRCUMFLEXEQUAL;
}
break;
}
return OP;
}
int
PyToken_ThreeChars(int c1, int c2, int c3)
{
switch (c1) {
case '<':
switch (c2) {
case '<':
switch (c3) {
case '=':
return LEFTSHIFTEQUAL;
}
break;
}
break;
case '>':
switch (c2) {
case '>':
switch (c3) {
case '=':
return RIGHTSHIFTEQUAL;
}
break;
}
break;
case '*':
switch (c2) {
case '*':
switch (c3) {
case '=':
return DOUBLESTAREQUAL;
}
break;
}
break;
case '/':
switch (c2) {
case '/':
switch (c3) {
case '=':
return DOUBLESLASHEQUAL;
}
break;
}
break;
case '.':
switch (c2) {
case '.':
switch (c3) {
case '.':
return ELLIPSIS;
}
break;
}
break;
}
return OP;
}
static int
indenterror(struct tok_state *tok)
{
if (tok->alterror) {
tok->done = E_TABSPACE;
tok->cur = tok->inp;
return 1;
}
if (tok->altwarning) {
PySys_WriteStderr("%s: inconsistent use of tabs and spaces "
"in indentation\n", tok->filename);
tok->altwarning = 0;
}
return 0;
}
#ifdef PGEN
#define verify_identifier(s,e) 1
#else
/* Verify that the identifier follows PEP 3131. */
static int
verify_identifier(char *start, char *end)
{
PyObject *s;
int result;
s = PyUnicode_DecodeUTF8(start, end-start, NULL);
if (s == NULL) {
PyErr_Clear();
return 0;
}
result = PyUnicode_IsIdentifier(s);
Py_DECREF(s);
return result;
}
#endif
/* Get next token, after space stripping etc. */
static int
tok_get(register struct tok_state *tok, char **p_start, char **p_end)
{
register int c;
int blankline, nonascii;
*p_start = *p_end = NULL;
nextline:
tok->start = NULL;
blankline = 0;
/* Get indentation level */
if (tok->atbol) {
register int col = 0;
register 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/tok->alttabsize + 1)
* tok->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]) {
if (indenterror(tok))
return ERRORTOKEN;
}
}
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]) {
if (indenterror(tok))
return ERRORTOKEN;
}
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]) {
if (indenterror(tok))
return ERRORTOKEN;
}
}
}
}
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 */
if (c == '#')
while (c != EOF && c != '\n')
c = tok_nextc(tok);
/* 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 r"", u"" and ur"" */
switch (c) {
case 'r':
case 'R':
c = tok_nextc(tok);
if (c == '"' || c == '\'')
goto letter_quote;
break;
case 'b':
case 'B':
c = tok_nextc(tok);
if (c == 'r' || c == 'R')
c = tok_nextc(tok);
if (c == '"' || c == '\'')
goto letter_quote;
break;
}
while (is_potential_identifier_char(c)) {
if (c >= 128)
nonascii = 1;
c = tok_nextc(tok);
}
tok_backup(tok, c);
if (nonascii &&
!verify_identifier(tok->start, tok->cur)) {
tok->done = E_IDENTIFIER;
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 == '.')
goto fraction;
#ifndef WITHOUT_COMPLEX
if (c == 'j' || c == 'J')
goto imaginary;
#endif
if (c == 'x' || c == 'X') {
/* Hex */
do {
c = tok_nextc(tok);
} while (isxdigit(c));
}
else if (c == 'o' || c == 'O') {
/* Octal */
do {
c = tok_nextc(tok);
} while ('0' <= c && c < '8');
}
else if (c == 'b' || c == 'B') {
/* Binary */
do {
c = tok_nextc(tok);
} while (c == '0' || c == '1');
}
else {
int nonzero = 0;
/* maybe old-style octal; c is first char of it */
/* in any case, allow '0' as a literal */
while (c == '0')
c = tok_nextc(tok);
while (isdigit(c)) {
nonzero = 1;
c = tok_nextc(tok);
}
if (c == '.')
goto fraction;
else if (c == 'e' || c == 'E')
goto exponent;
#ifndef WITHOUT_COMPLEX
else if (c == 'j' || c == 'J')
goto imaginary;
#endif
else if (nonzero) {
tok->done = E_TOKEN;
tok_backup(tok, c);
return ERRORTOKEN;
}
}
}
else {
/* Decimal */
do {
c = tok_nextc(tok);
} while (isdigit(c));
{
/* Accept floating point numbers. */
if (c == '.') {
fraction:
/* Fraction */
do {
c = tok_nextc(tok);
} while (isdigit(c));
}
if (c == 'e' || c == 'E') {
exponent:
/* Exponent part */
c = tok_nextc(tok);
if (c == '+' || c == '-')
c = tok_nextc(tok);
if (!isdigit(c)) {
tok->done = E_TOKEN;
tok_backup(tok, c);
return ERRORTOKEN;
}
do {
c = tok_nextc(tok);
} while (isdigit(c));
}
#ifndef WITHOUT_COMPLEX
if (c == 'j' || c == 'J')
/* Imaginary part */
imaginary:
c = tok_nextc(tok);
#endif
}
}
tok_backup(tok, c);
*p_start = tok->start;
*p_end = tok->cur;
return NUMBER;
}
letter_quote:
/* String */
if (c == '\'' || c == '"') {
Py_ssize_t quote2 = tok->cur - tok->start + 1;
int quote = c;
int triple = 0;
int tripcount = 0;
for (;;) {
c = tok_nextc(tok);
if (c == '\n') {
if (!triple) {
tok->done = E_EOLS;
tok_backup(tok, c);
return ERRORTOKEN;
}
tripcount = 0;
tok->cont_line = 1; /* multiline string. */
}
else if (c == EOF) {
if (triple)
tok->done = E_EOFS;
else
tok->done = E_EOLS;
tok->cur = tok->inp;
return ERRORTOKEN;
}
else if (c == quote) {
tripcount++;
if (tok->cur - tok->start == quote2) {
c = tok_nextc(tok);
if (c == quote) {
triple = 1;
tripcount = 0;
continue;
}
tok_backup(tok, c);
}
if (!triple || tripcount == 3)
break;
}
else if (c == '\\') {
tripcount = 0;
c = tok_nextc(tok);
if (c == EOF) {
tok->done = E_EOLS;
tok->cur = tok->inp;
return ERRORTOKEN;
}
}
else
tripcount = 0;
}
*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 '{':
tok->level++;
break;
case ')':
case ']':
case '}':
tok->level--;
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;
}
#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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