mirror of
https://github.com/qpdf/qpdf.git
synced 2024-11-01 03:12:29 +00:00
463 lines
8.8 KiB
C++
463 lines
8.8 KiB
C++
#include <qpdf/QPDFTokenizer.hh>
|
|
|
|
// DO NOT USE ctype -- it is locale dependent for some things, and
|
|
// it's not worth the risk of including it in case it may accidentally
|
|
// be used.
|
|
|
|
#include <qpdf/PCRE.hh>
|
|
#include <qpdf/QTC.hh>
|
|
|
|
#include <stdexcept>
|
|
#include <string.h>
|
|
|
|
// See note above about ctype.
|
|
static bool is_hex_digit(char ch)
|
|
{
|
|
return (strchr("0123456789abcdefABCDEF", ch) != 0);
|
|
}
|
|
|
|
QPDFTokenizer::QPDFTokenizer() :
|
|
pound_special_in_name(true)
|
|
{
|
|
reset();
|
|
}
|
|
|
|
void
|
|
QPDFTokenizer::allowPoundAnywhereInName()
|
|
{
|
|
QTC::TC("qpdf", "QPDFTokenizer allow pound anywhere in name");
|
|
this->pound_special_in_name = false;
|
|
}
|
|
|
|
void
|
|
QPDFTokenizer::reset()
|
|
{
|
|
state = st_top;
|
|
type = tt_bad;
|
|
val = "";
|
|
raw_val = "";
|
|
error_message = "";
|
|
unread_char = false;
|
|
char_to_unread = '\0';
|
|
string_depth = 0;
|
|
string_ignoring_newline = false;
|
|
last_char_was_bs = false;
|
|
}
|
|
|
|
void
|
|
QPDFTokenizer::presentCharacter(char ch)
|
|
{
|
|
static PCRE num_re("^[\\+\\-]?(?:\\.\\d+|\\d+(?:\\.\\d+)?)$");
|
|
|
|
if (state == st_token_ready)
|
|
{
|
|
throw std::logic_error(
|
|
"INTERNAL ERROR: QPDF tokenizer presented character "
|
|
"while token is waiting");
|
|
}
|
|
|
|
char orig_ch = ch;
|
|
|
|
// State machine is implemented such that some characters may be
|
|
// handled more than once. This happens whenever you have to use
|
|
// the character that caused a state change in the new state.
|
|
|
|
bool handled = true;
|
|
if (state == st_top)
|
|
{
|
|
// Note: we specifically do not use ctype here. It is
|
|
// locale-dependent.
|
|
if (strchr(" \t\n\v\f\r", ch))
|
|
{
|
|
// ignore
|
|
}
|
|
else if (ch == '%')
|
|
{
|
|
// Discard comments
|
|
state = st_in_comment;
|
|
}
|
|
else if (ch == '(')
|
|
{
|
|
string_depth = 1;
|
|
string_ignoring_newline = false;
|
|
memset(bs_num_register, '\0', sizeof(bs_num_register));
|
|
last_char_was_bs = false;
|
|
state = st_in_string;
|
|
}
|
|
else if (ch == '<')
|
|
{
|
|
state = st_lt;
|
|
}
|
|
else if (ch == '>')
|
|
{
|
|
state = st_gt;
|
|
}
|
|
else
|
|
{
|
|
val += ch;
|
|
if (ch == ')')
|
|
{
|
|
type = tt_bad;
|
|
QTC::TC("qpdf", "QPDF_Tokenizer bad )");
|
|
error_message = "unexpected )";
|
|
state = st_token_ready;
|
|
}
|
|
else if (ch == '[')
|
|
{
|
|
type = tt_array_open;
|
|
state = st_token_ready;
|
|
}
|
|
else if (ch == ']')
|
|
{
|
|
type = tt_array_close;
|
|
state = st_token_ready;
|
|
}
|
|
else if (ch == '{')
|
|
{
|
|
type = tt_brace_open;
|
|
state = st_token_ready;
|
|
}
|
|
else if (ch == '}')
|
|
{
|
|
type = tt_brace_close;
|
|
state = st_token_ready;
|
|
}
|
|
else
|
|
{
|
|
state = st_literal;
|
|
}
|
|
}
|
|
}
|
|
else if (state == st_in_comment)
|
|
{
|
|
if ((ch == '\r') || (ch == '\n'))
|
|
{
|
|
state = st_top;
|
|
}
|
|
}
|
|
else if (state == st_lt)
|
|
{
|
|
if (ch == '<')
|
|
{
|
|
val = "<<";
|
|
type = tt_dict_open;
|
|
state = st_token_ready;
|
|
}
|
|
else
|
|
{
|
|
handled = false;
|
|
state = st_in_hexstring;
|
|
}
|
|
}
|
|
else if (state == st_gt)
|
|
{
|
|
if (ch == '>')
|
|
{
|
|
val = ">>";
|
|
type = tt_dict_close;
|
|
state = st_token_ready;
|
|
}
|
|
else
|
|
{
|
|
val = ">";
|
|
type = tt_bad;
|
|
QTC::TC("qpdf", "QPDF_Tokenizer bad >");
|
|
error_message = "unexpected >";
|
|
unread_char = true;
|
|
char_to_unread = ch;
|
|
state = st_token_ready;
|
|
}
|
|
}
|
|
else if (state == st_in_string)
|
|
{
|
|
if (string_ignoring_newline && (! ((ch == '\r') || (ch == '\n'))))
|
|
{
|
|
string_ignoring_newline = false;
|
|
}
|
|
|
|
unsigned int bs_num_count = strlen(bs_num_register);
|
|
bool ch_is_octal = ((ch >= '0') && (ch <= '7'));
|
|
if ((bs_num_count == 3) || ((bs_num_count > 0) && (! ch_is_octal)))
|
|
{
|
|
// We've accumulated \ddd. PDF Spec says to ignore
|
|
// high-order overflow.
|
|
val += (char) strtol(bs_num_register, 0, 8);
|
|
memset(bs_num_register, '\0', sizeof(bs_num_register));
|
|
bs_num_count = 0;
|
|
}
|
|
|
|
if (string_ignoring_newline && ((ch == '\r') || (ch == '\n')))
|
|
{
|
|
// ignore
|
|
}
|
|
else if (ch_is_octal && (last_char_was_bs || (bs_num_count > 0)))
|
|
{
|
|
bs_num_register[bs_num_count++] = ch;
|
|
}
|
|
else if (last_char_was_bs)
|
|
{
|
|
switch (ch)
|
|
{
|
|
case 'n':
|
|
val += '\n';
|
|
break;
|
|
|
|
case 'r':
|
|
val += '\r';
|
|
break;
|
|
|
|
case 't':
|
|
val += '\t';
|
|
break;
|
|
|
|
case 'b':
|
|
val += '\b';
|
|
break;
|
|
|
|
case 'f':
|
|
val += '\f';
|
|
break;
|
|
|
|
case '\r':
|
|
case '\n':
|
|
string_ignoring_newline = true;
|
|
break;
|
|
|
|
default:
|
|
// PDF spec says backslash is ignored before anything else
|
|
val += ch;
|
|
break;
|
|
}
|
|
}
|
|
else if (ch == '\\')
|
|
{
|
|
// last_char_was_bs is set/cleared below as appropriate
|
|
if (bs_num_count)
|
|
{
|
|
throw std::logic_error(
|
|
"INTERNAL ERROR: QPDFTokenizer: bs_num_count != 0 "
|
|
"when ch == '\\'");
|
|
}
|
|
}
|
|
else if (ch == '(')
|
|
{
|
|
val += ch;
|
|
++string_depth;
|
|
}
|
|
else if ((ch == ')') && (--string_depth == 0))
|
|
{
|
|
type = tt_string;
|
|
state = st_token_ready;
|
|
}
|
|
else
|
|
{
|
|
val += ch;
|
|
}
|
|
|
|
last_char_was_bs = ((! last_char_was_bs) && (ch == '\\'));
|
|
}
|
|
else if (state == st_literal)
|
|
{
|
|
if (strchr(" \t\n\v\f\r()<>[]{}/%", ch) != 0)
|
|
{
|
|
// A C-locale whitespace character or delimiter terminates
|
|
// token. It is important to unread the whitespace
|
|
// character even though it is ignored since it may be the
|
|
// newline after a stream keyword. Removing it here could
|
|
// make the stream-reading code break on some files,
|
|
// though not on any files in the test suite as of this
|
|
// writing.
|
|
|
|
type = tt_word;
|
|
unread_char = true;
|
|
char_to_unread = ch;
|
|
state = st_token_ready;
|
|
}
|
|
else
|
|
{
|
|
val += ch;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
handled = false;
|
|
}
|
|
|
|
|
|
if (handled)
|
|
{
|
|
// okay
|
|
}
|
|
else if (state == st_in_hexstring)
|
|
{
|
|
if (ch == '>')
|
|
{
|
|
type = tt_string;
|
|
state = st_token_ready;
|
|
if (val.length() % 2)
|
|
{
|
|
// PDF spec says odd hexstrings have implicit
|
|
// trailing 0.
|
|
val += '0';
|
|
}
|
|
char num[3];
|
|
num[2] = '\0';
|
|
std::string nval;
|
|
for (unsigned int i = 0; i < val.length(); i += 2)
|
|
{
|
|
num[0] = val[i];
|
|
num[1] = val[i+1];
|
|
char nch = (char)(strtol(num, 0, 16));
|
|
nval += nch;
|
|
}
|
|
val = nval;
|
|
}
|
|
else if (is_hex_digit(ch))
|
|
{
|
|
val += ch;
|
|
}
|
|
else if (strchr(" \t\n\v\f\r", ch))
|
|
{
|
|
// ignore
|
|
}
|
|
else
|
|
{
|
|
type = tt_bad;
|
|
QTC::TC("qpdf", "QPDF_Tokenizer bad (");
|
|
error_message = std::string("invalid character (") +
|
|
ch + ") in hexstring";
|
|
state = st_token_ready;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
throw std::logic_error(
|
|
"INTERNAL ERROR: invalid state while reading token");
|
|
}
|
|
|
|
if ((state == st_token_ready) && (type == tt_word))
|
|
{
|
|
if ((val.length() > 0) && (val[0] == '/'))
|
|
{
|
|
type = tt_name;
|
|
// Deal with # in name token. Note: '/' by itself is a
|
|
// valid name, so don't strip leading /. That way we
|
|
// don't have to deal with the empty string as a name.
|
|
std::string nval = "/";
|
|
char const* valstr = val.c_str() + 1;
|
|
for (char const* p = valstr; *p; ++p)
|
|
{
|
|
if ((*p == '#') && this->pound_special_in_name)
|
|
{
|
|
if (p[1] && p[2] &&
|
|
is_hex_digit(p[1]) && is_hex_digit(p[2]))
|
|
{
|
|
char num[3];
|
|
num[0] = p[1];
|
|
num[1] = p[2];
|
|
num[2] = '\0';
|
|
char ch = (char)(strtol(num, 0, 16));
|
|
if (ch == '\0')
|
|
{
|
|
type = tt_bad;
|
|
QTC::TC("qpdf", "QPDF_Tokenizer null in name");
|
|
error_message =
|
|
"null character not allowed in name token";
|
|
nval += "#00";
|
|
}
|
|
else
|
|
{
|
|
nval += ch;
|
|
}
|
|
p += 2;
|
|
}
|
|
else
|
|
{
|
|
QTC::TC("qpdf", "QPDF_Tokenizer bad name");
|
|
type = tt_bad;
|
|
error_message = "invalid name token";
|
|
nval += *p;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
nval += *p;
|
|
}
|
|
}
|
|
val = nval;
|
|
}
|
|
else if (num_re.match(val.c_str()))
|
|
{
|
|
if (val.find('.') != std::string::npos)
|
|
{
|
|
type = tt_real;
|
|
}
|
|
else
|
|
{
|
|
type = tt_integer;
|
|
}
|
|
}
|
|
else if ((val == "true") || (val == "false"))
|
|
{
|
|
type = tt_bool;
|
|
}
|
|
else if (val == "null")
|
|
{
|
|
type = tt_null;
|
|
}
|
|
else
|
|
{
|
|
// I don't really know what it is, so leave it as tt_word.
|
|
// Lots of cases ($, #, etc.) other than actual words fall
|
|
// into this category, but that's okay at least for now.
|
|
type = tt_word;
|
|
}
|
|
}
|
|
|
|
if (! (betweenTokens() || ((state == st_token_ready) && unread_char)))
|
|
{
|
|
this->raw_val += orig_ch;
|
|
}
|
|
}
|
|
|
|
void
|
|
QPDFTokenizer::presentEOF()
|
|
{
|
|
switch (state)
|
|
{
|
|
case st_token_ready:
|
|
case st_top:
|
|
// okay
|
|
break;
|
|
|
|
case st_in_comment:
|
|
state = st_top;
|
|
break;
|
|
|
|
default:
|
|
type = tt_bad;
|
|
error_message = "EOF while reading token";
|
|
state = st_token_ready;
|
|
}
|
|
}
|
|
|
|
bool
|
|
QPDFTokenizer::getToken(Token& token, bool& unread_char, char& ch)
|
|
{
|
|
bool ready = (this->state == st_token_ready);
|
|
unread_char = this->unread_char;
|
|
ch = this->char_to_unread;
|
|
if (ready)
|
|
{
|
|
token = Token(type, val, raw_val, error_message);
|
|
reset();
|
|
}
|
|
return ready;
|
|
}
|
|
|
|
bool
|
|
QPDFTokenizer::betweenTokens()
|
|
{
|
|
return ((state == st_top) || (state == st_in_comment));
|
|
}
|