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openmw/components/compiler/scanner.cpp

655 lines
18 KiB
C++

#include "scanner.hpp"
#include <cassert>
#include <sstream>
#include "errorhandler.hpp"
#include "exception.hpp"
#include "extensions.hpp"
#include "parser.hpp"
#include <components/misc/strings/conversion.hpp>
#include <components/misc/strings/lower.hpp>
namespace
{
bool startsComparisonOperator(const Compiler::MultiChar& c)
{
return c == '=' || c == '<' || c == '>' || c == '!';
}
bool validComparisonOperatorCharacter(const Compiler::MultiChar& c)
{
return startsComparisonOperator(c) || c == ' ' || c == '\t';
}
}
namespace Compiler
{
bool Scanner::get(MultiChar& c)
{
if (!c.getFrom(mStream))
return false;
mPrevLoc = mLoc;
if (c == '\n')
{
mStrictKeywords = false;
mTolerantNames = false;
mExpectName = false;
mLoc.mColumn = 0;
++mLoc.mLine;
mLoc.mLiteral.clear();
mIgnoreSpecial = true;
}
else
{
++mLoc.mColumn;
c.appendTo(mLoc.mLiteral);
}
return true;
}
void Scanner::putback(MultiChar& c)
{
c.putback(mStream);
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;
}
MultiChar c;
if (!get(c))
{
parser.parseEOF(*this);
return false;
}
else if (c == ';')
{
std::string comment;
c.appendTo(comment);
while (get(c))
{
if (c == '\n')
{
putback(c);
break;
}
else
c.appendTo(comment);
}
TokenLoc loc(mLoc);
mLoc.mLiteral.clear();
return parser.parseComment(comment, loc, *this);
}
else if (c.isWhitespace())
{
mLoc.mLiteral.clear();
return true;
}
else if (c == ':')
{
// treat : as a whitespace :(
mLoc.mLiteral.clear();
return true;
}
else if (c.isAlpha() || c == '_' || c == '"')
{
mIgnoreSpecial = false;
bool cont = false;
if (scanName(c, parser, cont))
{
mLoc.mLiteral.clear();
return cont;
}
}
else if (c.isDigit())
{
mIgnoreSpecial = false;
bool cont = false;
bool scanned = mExpectName ? scanName(c, parser, cont) : scanInt(c, parser, cont);
if (scanned)
{
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(MultiChar& c, Parser& parser, bool& cont)
{
assert(c != '\0');
std::string value;
c.appendTo(value);
while (get(c))
{
if (c.isDigit())
{
c.appendTo(value);
}
else if (!c.isMinusSign() && isStringCharacter(c))
{
/// workaround that allows names to begin with digits
return scanName(c, parser, cont, value);
}
else if (c == '.')
{
return scanFloat(value, parser, cont);
}
else
{
putback(c);
break;
}
}
TokenLoc loc(mLoc);
mLoc.mLiteral.clear();
cont = parser.parseInt(Misc::StringUtils::toNumeric<int>(value, 0), loc, *this);
return true;
}
bool Scanner::scanFloat(const std::string& intValue, Parser& parser, bool& cont)
{
std::string value = intValue + ".";
MultiChar c;
bool empty = intValue.empty() || intValue == "-";
bool error = false;
while (get(c))
{
if (c.isDigit())
{
c.appendTo(value);
empty = false;
}
else if (c.isAlpha() || c == '_')
error = true;
else
{
putback(c);
break;
}
}
if (empty || error)
return false;
TokenLoc loc(mLoc);
mLoc.mLiteral.clear();
cont = parser.parseFloat(Misc::StringUtils::toNumeric<float>(value, 0.0f), loc, *this);
return true;
}
static const char* sKeywords[] = {
"begin",
"end",
"short",
"long",
"float",
"if",
"endif",
"else",
"elseif",
"while",
"endwhile",
"return",
"messagebox",
"set",
"to",
nullptr,
};
bool Scanner::scanName(MultiChar& c, Parser& parser, bool& cont, std::string name)
{
c.appendTo(name);
if (!scanName(name))
return false;
else if (name.empty())
return true;
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);
bool isKeyword = false;
for (; sKeywords[i]; ++i)
if (lowerCase == sKeywords[i])
{
isKeyword = true;
break;
}
// Russian localization and some mods use a quirk - add newline character directly
// to compiled bytecode via HEX-editor to implement multiline messageboxes.
// Of course, original editor can not compile such script.
// Allow messageboxes to bypass the "incomplete string or name" error.
if (lowerCase == "messagebox")
enableIgnoreNewlines();
else if (isKeyword)
mIgnoreNewline = false;
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)
{
MultiChar c;
bool error = false;
while (get(c))
{
if (!name.empty() && name[0] == '"')
{
if (c == '"')
{
c.appendTo(name);
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')
{
if (mIgnoreNewline)
mErrorHandler.warning("string contains newline character, make sure that it is intended", mLoc);
else
{
bool allWhitespace = true;
for (size_t i = 1; i < name.size(); i++)
{
// ignore comments
if (name[i] == ';')
break;
else if (name[i] != '\t' && name[i] != ' ' && name[i] != '\r')
{
allWhitespace = false;
break;
}
}
if (allWhitespace)
{
name.clear();
mLoc.mLiteral.clear();
mErrorHandler.warning("unterminated empty string", mLoc);
return true;
}
error = true;
mErrorHandler.error("incomplete string or name", mLoc);
break;
}
}
}
else if (!(c == '"' && name.empty()))
{
if (!isStringCharacter(c) && !(mTolerantNames && (c == '.' || c == '-')))
{
putback(c);
break;
}
}
c.appendTo(name);
}
return !error;
}
bool Scanner::scanSpecial(MultiChar& c, Parser& parser, bool& cont)
{
bool expectName = mExpectName;
mExpectName = false;
int special = -1;
if (c == '\n')
special = S_newline;
else if (mIgnoreSpecial)
{
// Ignore junk special characters
TokenLoc loc = mLoc;
while (get(c))
{
if (c.isAlpha() || c == '_' || c == '"' || c.isDigit() || c == ';' || c == '\n')
{
putback(c);
break;
}
c.appendTo(loc.mLiteral);
}
mErrorHandler.warning("Stray special character at start of line", loc);
cont = true;
return true;
}
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 == '.')
{
MultiChar next;
// check, if this starts a float literal
if (get(next))
{
putback(next);
if (next.isDigit())
return scanFloat("", parser, cont);
}
special = S_member;
}
else if (startsComparisonOperator(c))
{
TokenLoc loc = mLoc;
std::string op;
c.appendTo(op);
while (get(c))
{
if (validComparisonOperatorCharacter(c))
c.appendTo(op);
else
{
putback(c);
break;
}
}
size_t end = op.size();
while (end > 0 && (op[end - 1] == '\t' || op[end - 1] == ' '))
--end;
switch (op[0])
{
case '=':
special = S_cmpEQ;
if (end != 2 || op[1] != '=')
mErrorHandler.warning("invalid operator " + op.substr(0, end) + ", treating it as ==", loc);
break;
case '<':
special = S_cmpLT;
if (op[1] == '=')
{
special = S_cmpLE;
if (end != 2)
mErrorHandler.warning("invalid operator " + op.substr(0, end) + ", treating it as <=", loc);
}
else if (end != 1)
mErrorHandler.warning("invalid operator " + op.substr(0, end) + ", treating it as <", loc);
break;
case '>':
special = S_cmpGT;
if (op[1] == '=')
{
special = S_cmpGE;
if (end != 2)
mErrorHandler.warning("invalid operator " + op.substr(0, end) + ", treating it as >=", loc);
}
else if (end != 1)
mErrorHandler.warning("invalid operator " + op.substr(0, end) + ", treating it as >", loc);
break;
case '!':
special = S_cmpNE;
if (end != 2 || op[1] != '=')
mErrorHandler.warning("invalid operator " + op.substr(0, end) + ", treating it as !=", loc);
break;
default:
return false;
}
}
else if (c.isMinusSign())
{
MultiChar next;
if (get(next))
{
if (next == '>')
special = S_ref;
else
{
putback(next);
special = S_minus;
}
}
else
special = S_minus;
}
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>";
else if (expectName && (special == S_member || special == S_minus))
{
bool tolerant = mTolerantNames;
mTolerantNames = true;
bool out = scanName(c, parser, cont);
mTolerantNames = tolerant;
return out;
}
TokenLoc loc(mLoc);
mLoc.mLiteral.clear();
cont = parser.parseSpecial(special, loc, *this);
return true;
}
bool Scanner::isStringCharacter(MultiChar& c, bool lookAhead)
{
if (lookAhead && c.isMinusSign())
{
/// \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.
MultiChar next;
if (next.peek(mStream) && isStringCharacter(next, false))
return true;
}
return c.isAlpha() || c.isDigit() || c == '_' ||
/// \todo disable this when doing more stricter compiling
c == '`' || c == '\'';
}
// 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)
, mIgnoreNewline(false)
, mExpectName(false)
, mIgnoreSpecial(true)
{
}
void Scanner::scan(Parser& parser)
{
while (scanToken(parser))
;
mExpectName = false;
}
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.emplace_back(Compiler::sKeywords[i]);
if (mExtensions)
mExtensions->listKeywords(keywords);
}
void Scanner::enableIgnoreNewlines()
{
mIgnoreNewline = true;
}
void Scanner::enableStrictKeywords()
{
mStrictKeywords = true;
}
void Scanner::enableTolerantNames()
{
mTolerantNames = true;
}
void Scanner::enableExpectName()
{
mExpectName = true;
}
}