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openmw-tes3mp/components/compiler/scanner.cpp

644 lines
16 KiB
C++

#include "scanner.hpp"
#include <cassert>
#include <cctype>
#include <sstream>
#include <algorithm>
#include <iterator>
#include "exception.hpp"
#include "errorhandler.hpp"
#include "parser.hpp"
#include "extensions.hpp"
#include <components/misc/stringops.hpp>
namespace Compiler
{
bool Scanner::get (char& c)
{
mStream.get (c);
if (!mStream.good())
return false;
mPrevLoc =mLoc;
if (c=='\n')
{
mStrictKeywords = false;
mTolerantNames = false;
mLoc.mColumn = 0;
++mLoc.mLine;
mLoc.mLiteral.clear();
}
else
{
++mLoc.mColumn;
mLoc.mLiteral += c;
}
return true;
}
void Scanner::putback (char c)
{
mStream.putback (c);
mLoc = mPrevLoc;
}
bool Scanner::scanToken (Parser& parser)
{
switch (mPutback)
{
case Putback_Special:
mPutback = Putback_None;
return parser.parseSpecial (mPutbackCode, mPutbackLoc, *this);
case Putback_Integer:
mPutback = Putback_None;
return parser.parseInt (mPutbackInteger, mPutbackLoc, *this);
case Putback_Float:
mPutback = Putback_None;
return parser.parseFloat (mPutbackFloat, mPutbackLoc, *this);
case Putback_Name:
mPutback = Putback_None;
return parser.parseName (mPutbackName, mPutbackLoc, *this);
case Putback_Keyword:
mPutback = Putback_None;
return parser.parseKeyword (mPutbackCode, mPutbackLoc, *this);
case Putback_None:
break;
}
char c;
if (!get (c))
{
parser.parseEOF (*this);
return false;
}
else if (c==';')
{
std::string comment;
comment += c;
while (get (c))
{
if (c=='\n')
{
putback (c);
break;
}
else
comment += c;
}
TokenLoc loc (mLoc);
mLoc.mLiteral.clear();
return parser.parseComment (comment, loc, *this);
}
else if (isWhitespace (c))
{
mLoc.mLiteral.clear();
return true;
}
else if (c==':')
{
// treat : as a whitespace :(
mLoc.mLiteral.clear();
return true;
}
else if (std::isalpha (c) || c=='_' || c=='"')
{
bool cont = false;
if (scanName (c, parser, cont))
{
mLoc.mLiteral.clear();
return cont;
}
}
else if (std::isdigit (c))
{
bool cont = false;
if (scanInt (c, parser, cont))
{
mLoc.mLiteral.clear();
return cont;
}
}
else if (c==13) // linux compatibility hack
{
return true;
}
else
{
bool cont = false;
if (scanSpecial (c, parser, cont))
{
mLoc.mLiteral.clear();
return cont;
}
}
TokenLoc loc (mLoc);
mLoc.mLiteral.clear();
mErrorHandler.error ("syntax error", loc);
throw SourceException();
}
bool Scanner::scanInt (char c, Parser& parser, bool& cont)
{
assert(c != '\0');
std::string value;
value += c;
bool error = false;
while (get (c))
{
if (std::isdigit (c))
{
value += c;
}
else if (c!='-' && isStringCharacter (c))
{
error = true;
value += c;
}
else if (c=='.')
{
if (error)
{
putback (c);
break;
}
return scanFloat (value, parser, cont);
}
else
{
putback (c);
break;
}
}
if (error)
{
/// workaround that allows names to begin with digits
/// \todo disable
TokenLoc loc (mLoc);
mLoc.mLiteral.clear();
cont = parser.parseName (value, loc, *this);
return true;
// return false;
}
TokenLoc loc (mLoc);
mLoc.mLiteral.clear();
std::istringstream stream (value);
int intValue = 0;
stream >> intValue;
cont = parser.parseInt (intValue, loc, *this);
return true;
}
bool Scanner::scanFloat (const std::string& intValue, Parser& parser, bool& cont)
{
std::string value = intValue + ".";
char c;
bool empty = intValue.empty() || intValue=="-";
bool error = false;
while (get (c))
{
if (std::isdigit (c))
{
value += c;
empty = false;
}
else if (std::isalpha (c) || c=='_')
error = true;
else
{
putback (c);
break;
}
}
if (empty || error)
return false;
TokenLoc loc (mLoc);
mLoc.mLiteral.clear();
std::istringstream stream (value);
float floatValue = 0;
stream >> floatValue;
cont = parser.parseFloat (floatValue, loc, *this);
return true;
}
static const char *sKeywords[] =
{
"begin", "end",
"short", "long", "float",
"if", "endif", "else", "elseif",
"while", "endwhile",
"return",
"messagebox",
"set", "to",
"getsquareroot",
"menumode",
"random",
"startscript", "stopscript", "scriptrunning",
"getdistance",
"getsecondspassed",
"enable", "disable", "getdisabled",
0
};
bool Scanner::scanName (char c, Parser& parser, bool& cont)
{
std::string name;
name += c;
if (!scanName (name))
return false;
TokenLoc loc (mLoc);
mLoc.mLiteral.clear();
if (name.size()>=2 && name[0]=='"' && name[name.size()-1]=='"')
{
name = name.substr (1, name.size()-2);
// allow keywords enclosed in ""
/// \todo optionally disable
if (mStrictKeywords)
{
cont = parser.parseName (name, loc, *this);
return true;
}
}
int i = 0;
std::string lowerCase = Misc::StringUtils::lowerCase(name);
for (; sKeywords[i]; ++i)
if (lowerCase==sKeywords[i])
break;
if (sKeywords[i])
{
cont = parser.parseKeyword (i, loc, *this);
return true;
}
if (mExtensions)
{
if (int keyword = mExtensions->searchKeyword (lowerCase))
{
cont = parser.parseKeyword (keyword, loc, *this);
return true;
}
}
cont = parser.parseName (name, loc, *this);
return true;
}
bool Scanner::scanName (std::string& name)
{
char c;
bool error = false;
while (get (c))
{
if (!name.empty() && name[0]=='"')
{
if (c=='"')
{
name += c;
break;
}
// ignoring escape sequences for now, because they are messing up stupid Windows path names.
// else if (c=='\\')
// {
// if (!get (c))
// {
// error = true;
// mErrorHandler.error ("incomplete escape sequence", mLoc);
// break;
// }
// }
else if (c=='\n')
{
error = true;
mErrorHandler.error ("incomplete string or name", mLoc);
break;
}
}
else if (!(c=='"' && name.empty()))
{
if (!isStringCharacter (c) && !(mTolerantNames && (c=='.' || c=='-')))
{
putback (c);
break;
}
}
name += c;
}
return !error;
}
bool Scanner::scanSpecial (char c, Parser& parser, bool& cont)
{
int special = -1;
if (c=='\n')
special = S_newline;
else if (c=='(' || c=='[') /// \todo option to disable the use of [ as alias for (
special = S_open;
else if (c==')' || c==']') /// \todo option to disable the use of ] as alias for )
special = S_close;
else if (c=='.')
{
// check, if this starts a float literal
if (get (c))
{
putback (c);
if (std::isdigit (c))
return scanFloat ("", parser, cont);
}
special = S_member;
}
else if (c=='=')
{
if (get (c))
{
/// \todo hack to allow a space in comparison operators (add option to disable)
if (c==' ' && !get (c))
special = S_cmpEQ;
else if (c=='=')
special = S_cmpEQ;
else if (c == '>' || c == '<') // Treat => and =< as ==
{
special = S_cmpEQ;
mErrorHandler.warning (std::string("invalid operator =") + c + ", treating it as ==", mLoc);
}
else
{
special = S_cmpEQ;
putback (c);
// return false;
/// Allow = as synonym for ==. \todo optionally disable for post-1.0 scripting improvements.
}
}
else
{
putback (c);
return false;
}
}
else if (c=='!')
{
if (get (c))
{
/// \todo hack to allow a space in comparison operators (add option to disable)
if (c==' ' && !get (c))
return false;
if (c=='=')
special = S_cmpNE;
else
{
putback (c);
return false;
}
}
else
return false;
}
else if (c=='-')
{
if (get (c))
{
if (c=='>')
special = S_ref;
else
{
putback (c);
special = S_minus;
}
}
else
special = S_minus;
}
else if (static_cast<unsigned char> (c)==0xe2)
{
/// Workaround for some translator who apparently can't keep his minus in order
/// \todo disable for later script formats
if (get (c) && static_cast<unsigned char> (c)==0x80 &&
get (c) && static_cast<unsigned char> (c)==0x93)
{
if (get (c))
{
if (c=='>')
special = S_ref;
else
{
putback (c);
special = S_minus;
}
}
else
special = S_minus;
}
else
{
mErrorHandler.error ("Invalid character", mLoc);
return false;
}
}
else if (c=='<')
{
if (get (c))
{
/// \todo hack to allow a space in comparison operators (add option to disable)
if (c==' ' && !get (c))
special = S_cmpLT;
else if (c=='=')
{
special = S_cmpLE;
if (get (c) && c!='=') // <== is a allowed as an alternative to <= :(
putback (c);
}
else
{
putback (c);
special = S_cmpLT;
}
}
else
special = S_cmpLT;
}
else if (c=='>')
{
if (get (c))
{
/// \todo hack to allow a space in comparison operators (add option to disable)
if (c==' ' && !get (c))
special = S_cmpGT;
else if (c=='=')
{
special = S_cmpGE;
if (get (c) && c!='=') // >== is a allowed as an alternative to >= :(
putback (c);
}
else
{
putback (c);
special = S_cmpGT;
}
}
else
special = S_cmpGT;
}
else if (c==',')
special = S_comma;
else if (c=='+')
special = S_plus;
else if (c=='*')
special = S_mult;
else if (c=='/')
special = S_div;
else
return false;
if (special==S_newline)
mLoc.mLiteral = "<newline>";
TokenLoc loc (mLoc);
mLoc.mLiteral.clear();
cont = parser.parseSpecial (special, loc, *this);
return true;
}
bool Scanner::isStringCharacter (char c, bool lookAhead)
{
return std::isalpha (c) || std::isdigit (c) || c=='_' ||
/// \todo disable this when doing more stricter compiling
c=='`' || c=='\'' ||
/// \todo disable this when doing more stricter compiling. Also, find out who is
/// responsible for allowing it in the first place and meet up with that person in
/// a dark alley.
(c=='-' && (!lookAhead || isStringCharacter (mStream.peek(), false)));
}
bool Scanner::isWhitespace (char c)
{
return c==' ' || c=='\t';
}
// constructor
Scanner::Scanner (ErrorHandler& errorHandler, std::istream& inputStream,
const Extensions *extensions)
: mErrorHandler (errorHandler), mStream (inputStream), mExtensions (extensions),
mPutback (Putback_None), mPutbackCode(0), mPutbackInteger(0), mPutbackFloat(0),
mStrictKeywords (false), mTolerantNames (false)
{
}
void Scanner::scan (Parser& parser)
{
while (scanToken (parser));
}
void Scanner::putbackSpecial (int code, const TokenLoc& loc)
{
mPutback = Putback_Special;
mPutbackCode = code;
mPutbackLoc = loc;
}
void Scanner::putbackInt (int value, const TokenLoc& loc)
{
mPutback = Putback_Integer;
mPutbackInteger = value;
mPutbackLoc = loc;
}
void Scanner::putbackFloat (float value, const TokenLoc& loc)
{
mPutback = Putback_Float;
mPutbackFloat = value;
mPutbackLoc = loc;
}
void Scanner::putbackName (const std::string& name, const TokenLoc& loc)
{
mPutback = Putback_Name;
mPutbackName = name;
mPutbackLoc = loc;
}
void Scanner::putbackKeyword (int keyword, const TokenLoc& loc)
{
mPutback = Putback_Keyword;
mPutbackCode = keyword;
mPutbackLoc = loc;
}
void Scanner::listKeywords (std::vector<std::string>& keywords)
{
for (int i=0; Compiler::sKeywords[i]; ++i)
keywords.push_back (Compiler::sKeywords[i]);
if (mExtensions)
mExtensions->listKeywords (keywords);
}
void Scanner::enableStrictKeywords()
{
mStrictKeywords = true;
}
void Scanner::enableTolerantNames()
{
mTolerantNames = true;
}
}