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// Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
// SPDX-License-Identifier: BSD-3-Clause
#include "qscriptsyntaxchecker_p.h"
#include "qscriptlexer_p.h"
#include "qscriptparser_p.h"
QT_BEGIN_NAMESPACE
namespace QScript {
SyntaxChecker::SyntaxChecker():
tos(0),
stack_size(0),
state_stack(0)
{
}
SyntaxChecker::~SyntaxChecker()
{
if (stack_size) {
qFree(state_stack);
}
}
bool SyntaxChecker::automatic(QScript::Lexer *lexer, int token) const
{
return token == T_RBRACE || token == 0 || lexer->prevTerminator();
}
SyntaxChecker::Result SyntaxChecker::checkSyntax(const QString &code)
{
const int INITIAL_STATE = 0;
QScript::Lexer lexer (/*engine=*/ 0);
lexer.setCode(code, /*lineNo*/ 1);
int yytoken = -1;
int saved_yytoken = -1;
QString error_message;
int error_lineno = -1;
int error_column = -1;
State checkerState = Valid;
reallocateStack();
tos = 0;
state_stack[++tos] = INITIAL_STATE;
while (true)
{
const int state = state_stack [tos];
if (yytoken == -1 && - TERMINAL_COUNT != action_index [state])
{
if (saved_yytoken == -1)
yytoken = lexer.lex();
else
{
yytoken = saved_yytoken;
saved_yytoken = -1;
}
}
int act = t_action (state, yytoken);
if (act == ACCEPT_STATE) {
if (lexer.error() == QScript::Lexer::UnclosedComment)
checkerState = Intermediate;
else
checkerState = Valid;
break;
} else if (act > 0) {
if (++tos == stack_size)
reallocateStack();
state_stack [tos] = act;
yytoken = -1;
}
else if (act < 0)
{
int r = - act - 1;
tos -= rhs [r];
act = state_stack [tos++];
if ((r == Q_SCRIPT_REGEXPLITERAL_RULE1)
|| (r == Q_SCRIPT_REGEXPLITERAL_RULE2)) {
// Skip the rest of the RegExp literal
bool rx = lexer.scanRegExp();
if (!rx) {
checkerState = Intermediate;
break;
}
}
state_stack [tos] = nt_action (act, lhs [r] - TERMINAL_COUNT);
}
else
{
if (saved_yytoken == -1 && automatic (&lexer, yytoken) && t_action (state, T_AUTOMATIC_SEMICOLON) > 0)
{
saved_yytoken = yytoken;
yytoken = T_SEMICOLON;
continue;
}
else if ((state == INITIAL_STATE) && (yytoken == 0)) {
// accept empty input
yytoken = T_SEMICOLON;
continue;
}
int ers = state;
int shifts = 0;
int reduces = 0;
int expected_tokens [3];
for (int tk = 0; tk < TERMINAL_COUNT; ++tk)
{
int k = t_action (ers, tk);
if (! k)
continue;
else if (k < 0)
++reduces;
else if (spell [tk])
{
if (shifts < 3)
expected_tokens [shifts] = tk;
++shifts;
}
}
error_message.clear ();
if (shifts && shifts < 3)
{
bool first = true;
for (int s = 0; s < shifts; ++s)
{
if (first)
error_message += QLatin1String ("Expected ");
else
error_message += QLatin1String (", ");
first = false;
error_message += QLatin1Char('`');
error_message += QLatin1String (spell [expected_tokens [s]]);
error_message += QLatin1Char('\'');
}
}
if (error_message.isEmpty())
error_message = lexer.errorMessage();
error_lineno = lexer.startLineNo();
error_column = lexer.startColumnNo();
checkerState = Error;
break;
}
}
if (checkerState == Error) {
if (lexer.error() == QScript::Lexer::UnclosedComment)
checkerState = Intermediate;
else if (yytoken == 0)
checkerState = Intermediate;
}
return Result(checkerState, error_lineno, error_column, error_message);
}
} // namespace QScript
QT_END_NAMESPACE
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