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DEFINITIONS
This source file includes following definitions.
- getChar
- lookChar
- getObj
- skipToNextLine
- isSpace
//========================================================================
//
// Lexer.cc
//
// Copyright 1996-2003 Glyph & Cog, LLC
//
//========================================================================
#include <aconf.h>
#ifdef USE_GCC_PRAGMAS
#pragma implementation
#endif
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <ctype.h>
#include "Lexer.h"
#include "Error.h"
//------------------------------------------------------------------------
// A '1' in this array means the character is white space. A '1' or
// '2' means the character ends a name or command.
static char specialChars[256] = {
1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 1, 1, 0, 0, // 0x
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 1x
1, 0, 0, 0, 0, 2, 0, 0, 2, 2, 0, 0, 0, 0, 0, 2, // 2x
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 2, 0, // 3x
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 4x
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 2, 0, 0, // 5x
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 6x
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 2, 0, 0, // 7x
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 8x
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 9x
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // ax
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // bx
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // cx
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // dx
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // ex
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 // fx
};
//------------------------------------------------------------------------
// Lexer
//------------------------------------------------------------------------
Lexer::Lexer(XRef *xref, Stream *str) {
Object obj;
curStr.initStream(str);
streams = new Array(xref);
streams->add(curStr.copy(&obj));
strPtr = 0;
freeArray = gTrue;
curStr.streamReset();
}
Lexer::Lexer(XRef *xref, Object *obj) {
Object obj2;
if (obj->isStream()) {
streams = new Array(xref);
freeArray = gTrue;
streams->add(obj->copy(&obj2));
} else {
streams = obj->getArray();
freeArray = gFalse;
}
strPtr = 0;
if (streams->getLength() > 0) {
streams->get(strPtr, &curStr);
curStr.streamReset();
}
}
static int illegalChars = 0;
Lexer::~Lexer() {
if (!curStr.isNone()) {
curStr.streamClose();
curStr.free();
}
if (freeArray) {
delete streams;
}
if(illegalChars)
error(0, "Illegal characters in hex string (%d)", illegalChars);
illegalChars = 0;
}
int Lexer::getChar() {
int c;
c = EOF;
while (!curStr.isNone() && (c = curStr.streamGetChar()) == EOF) {
curStr.streamClose();
curStr.free();
++strPtr;
if (strPtr < streams->getLength()) {
streams->get(strPtr, &curStr);
curStr.streamReset();
}
}
return c;
}
int Lexer::lookChar() {
if (curStr.isNone()) {
return EOF;
}
return curStr.streamLookChar();
}
Object *Lexer::getObj(Object *obj) {
char *p;
int c, c2;
GBool comment, neg, done;
int numParen;
int xi;
double xf, scale;
GString *s;
int n, m;
// skip whitespace and comments
comment = gFalse;
while (1) {
if ((c = getChar()) == EOF) {
return obj->initEOF();
}
if (comment) {
if (c == '\r' || c == '\n')
comment = gFalse;
} else if (c == '%') {
comment = gTrue;
} else if (specialChars[c] != 1) {
break;
}
}
// start reading token
switch (c) {
// number
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
case '-': case '.':
neg = gFalse;
xi = 0;
if (c == '-') {
neg = gTrue;
} else if (c == '.') {
goto doReal;
} else {
xi = c - '0';
}
while (1) {
c = lookChar();
if (isdigit(c)) {
getChar();
xi = xi * 10 + (c - '0');
} else if (c == '.') {
getChar();
goto doReal;
} else {
break;
}
}
if (neg)
xi = -xi;
obj->initInt(xi);
break;
doReal:
xf = xi;
scale = 0.1;
while (1) {
c = lookChar();
if (c == '-') {
// ignore minus signs in the middle of numbers to match
// Adobe's behavior
error(getPos(), "Badly formatted number");
getChar();
continue;
}
if (!isdigit(c)) {
break;
}
getChar();
xf = xf + scale * (c - '0');
scale *= 0.1;
}
if (neg)
xf = -xf;
obj->initReal(xf);
break;
// string
case '(':
p = tokBuf;
n = 0;
numParen = 1;
done = gFalse;
s = NULL;
do {
c2 = EOF;
switch (c = getChar()) {
case EOF:
#if 0
// This breaks some PDF files, e.g., ones from Photoshop.
case '\r':
case '\n':
#endif
error(getPos(), "Unterminated string");
done = gTrue;
break;
case '(':
++numParen;
c2 = c;
break;
case ')':
if (--numParen == 0) {
done = gTrue;
} else {
c2 = c;
}
break;
case '\\':
switch (c = getChar()) {
case 'n':
c2 = '\n';
break;
case 'r':
c2 = '\r';
break;
case 't':
c2 = '\t';
break;
case 'b':
c2 = '\b';
break;
case 'f':
c2 = '\f';
break;
case '\\':
case '(':
case ')':
c2 = c;
break;
case '0': case '1': case '2': case '3':
case '4': case '5': case '6': case '7':
c2 = c - '0';
c = lookChar();
if (c >= '0' && c <= '7') {
getChar();
c2 = (c2 << 3) + (c - '0');
c = lookChar();
if (c >= '0' && c <= '7') {
getChar();
c2 = (c2 << 3) + (c - '0');
}
}
break;
case '\r':
c = lookChar();
if (c == '\n') {
getChar();
}
break;
case '\n':
break;
case EOF:
error(getPos(), "Unterminated string");
done = gTrue;
break;
default:
c2 = c;
break;
}
break;
default:
c2 = c;
break;
}
if (c2 != EOF) {
if (n == tokBufSize) {
if (!s)
s = new GString(tokBuf, tokBufSize);
else
s->append(tokBuf, tokBufSize);
p = tokBuf;
n = 0;
}
*p++ = (char)c2;
++n;
}
} while (!done);
if (!s)
s = new GString(tokBuf, n);
else
s->append(tokBuf, n);
obj->initString(s);
break;
// name
case '/':
p = tokBuf;
n = 0;
while ((c = lookChar()) != EOF && !specialChars[c]) {
getChar();
if (c == '#') {
c2 = lookChar();
if (c2 >= '0' && c2 <= '9') {
c = c2 - '0';
} else if (c2 >= 'A' && c2 <= 'F') {
c = c2 - 'A' + 10;
} else if (c2 >= 'a' && c2 <= 'f') {
c = c2 - 'a' + 10;
} else {
goto notEscChar;
}
getChar();
c <<= 4;
c2 = getChar();
if (c2 >= '0' && c2 <= '9') {
c += c2 - '0';
} else if (c2 >= 'A' && c2 <= 'F') {
c += c2 - 'A' + 10;
} else if (c2 >= 'a' && c2 <= 'f') {
c += c2 - 'a' + 10;
} else {
illegalChars++;
//error(getPos(), "Illegal digit in hex char in name");
}
}
notEscChar:
if (++n == tokBufSize) {
error(getPos(), "Name token too long");
break;
}
*p++ = c;
}
*p = '\0';
obj->initName(tokBuf);
break;
// array punctuation
case '[':
case ']':
tokBuf[0] = c;
tokBuf[1] = '\0';
obj->initCmd(tokBuf);
break;
// hex string or dict punctuation
case '<':
c = lookChar();
// dict punctuation
if (c == '<') {
getChar();
tokBuf[0] = tokBuf[1] = '<';
tokBuf[2] = '\0';
obj->initCmd(tokBuf);
// hex string
} else {
p = tokBuf;
m = n = 0;
c2 = 0;
s = NULL;
while (1) {
c = getChar();
if (c == '>') {
break;
} else if (c == EOF) {
error(getPos(), "Unterminated hex string");
break;
} else if (specialChars[c] != 1) {
c2 = c2 << 4;
if (c >= '0' && c <= '9')
c2 += c - '0';
else if (c >= 'A' && c <= 'F')
c2 += c - 'A' + 10;
else if (c >= 'a' && c <= 'f')
c2 += c - 'a' + 10;
else {
illegalChars++;
//error(getPos(), "Illegal character <%02x> in hex string", c);
}
if (++m == 2) {
if (n == tokBufSize) {
if (!s)
s = new GString(tokBuf, tokBufSize);
else
s->append(tokBuf, tokBufSize);
p = tokBuf;
n = 0;
}
*p++ = (char)c2;
++n;
c2 = 0;
m = 0;
}
}
}
if (!s)
s = new GString(tokBuf, n);
else
s->append(tokBuf, n);
if (m == 1)
s->append((char)(c2 << 4));
obj->initString(s);
}
break;
// dict punctuation
case '>':
c = lookChar();
if (c == '>') {
getChar();
tokBuf[0] = tokBuf[1] = '>';
tokBuf[2] = '\0';
obj->initCmd(tokBuf);
} else {
illegalChars++;
//error(getPos(), "Illegal character '>'");
obj->initError();
}
break;
// error
case ')':
case '{':
case '}':
//error(getPos(), "Illegal character '%c'", c);
illegalChars++;
obj->initError();
break;
// command
default:
p = tokBuf;
*p++ = c;
n = 1;
while ((c = lookChar()) != EOF && !specialChars[c]) {
getChar();
if (++n == tokBufSize) {
error(getPos(), "Command token too long");
break;
}
*p++ = c;
}
*p = '\0';
if (tokBuf[0] == 't' && !strcmp(tokBuf, "true")) {
obj->initBool(gTrue);
} else if (tokBuf[0] == 'f' && !strcmp(tokBuf, "false")) {
obj->initBool(gFalse);
} else if (tokBuf[0] == 'n' && !strcmp(tokBuf, "null")) {
obj->initNull();
} else {
obj->initCmd(tokBuf);
}
break;
}
return obj;
}
void Lexer::skipToNextLine() {
int c;
while (1) {
c = getChar();
if (c == EOF || c == '\n') {
return;
}
if (c == '\r') {
if ((c = lookChar()) == '\n') {
getChar();
}
return;
}
}
}
GBool Lexer::isSpace(int c) {
return c >= 0 && c <= 0xff && specialChars[c] == 1;
}