Cppcheck report - LibreOffice 2020-06-13 19:58:00 41c465b5ee443ec04441077b5eb80f263336ea8a, CppCheck 2020-06-13 18:19:47 6d5d12f283cf568d2dfe09aa77cb41f34b322d62: slideshow/source/engine/smilfunctionparser.cxx

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
 * This file is part of the LibreOffice project.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * This file incorporates work covered by the following license notice:
 *
 *   Licensed to the Apache Software Foundation (ASF) under one or more
 *   contributor license agreements. See the NOTICE file distributed
 *   with this work for additional information regarding copyright
 *   ownership. The ASF licenses this file to you under the Apache
 *   License, Version 2.0 (the "License"); you may not use this file
 *   except in compliance with the License. You may obtain a copy of
 *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
 */


#include <tools/diagnose_ex.h>

#include <slideshowexceptions.hxx>
#include <smilfunctionparser.hxx>
#include <expressionnodefactory.hxx>

#include <rtl/ustring.hxx>
#include <sal/log.hxx>

// Makes parser a static resource,
// we're synchronized externally.
// But watch out, the parser might have
// state not visible to this code!
#define BOOST_SPIRIT_SINGLE_GRAMMAR_INSTANCE

#if defined(DBG_UTIL)
#define BOOST_SPIRIT_DEBUG
#endif
#include <boost/spirit/include/classic_core.hpp>

#include <iostream>
#include <functional>
#include <algorithm>
#include <stack>


/* Implementation of SmilFunctionParser class */

namespace slideshow::internal
{
        namespace
        {
            typedef const char*                   StringIteratorT;

            struct ParserContext
            {
                typedef ::std::stack< std::shared_ptr<ExpressionNode> > OperandStack;

                // stores a stack of not-yet-evaluated operands. This is used
                // by the operators (i.e. '+', '*', 'sin' etc.) to pop their
                // arguments from. If all arguments to an operator are constant,
                // the operator pushes a precalculated result on the stack, and
                // a composite ExpressionNode otherwise.
                OperandStack                maOperandStack;

                // bounds of the shape this expression is associated with
                ::basegfx::B2DRectangle     maShapeBounds;

                // when true, enable usage of time-dependent variable '$'
                // in expressions
                bool                        mbParseAnimationFunction;
            };

            typedef ::std::shared_ptr< ParserContext > ParserContextSharedPtr;


            template< typename Generator > class ShapeBoundsFunctor
            {
            public:
                ShapeBoundsFunctor( Generator                       aGenerator,
                                    const ParserContextSharedPtr&   rContext ) :
                    maGenerator( aGenerator ),
                    mpContext( rContext )
                {
                    ENSURE_OR_THROW( mpContext,
                                      "ShapeBoundsFunctor::ShapeBoundsFunctor(): Invalid context" );
                }

                void operator()( StringIteratorT, StringIteratorT ) const
                {
                    mpContext->maOperandStack.push(
                        ExpressionNodeFactory::createConstantValueExpression(
                            maGenerator( mpContext->maShapeBounds ) ) );
                }

            private:
                Generator               maGenerator;
                ParserContextSharedPtr  mpContext;
            };

            template< typename Generator > ShapeBoundsFunctor< Generator >
                makeShapeBoundsFunctor( const Generator&                rGenerator,
                                        const ParserContextSharedPtr&   rContext )
            {
                return ShapeBoundsFunctor<Generator>(rGenerator, rContext);
            }

            /** Generate apriori constant value
             */
            class ConstantFunctor
            {
            public:
                ConstantFunctor( double                         rValue,
                                 const ParserContextSharedPtr&  rContext ) :
                    mnValue( rValue ),
                    mpContext( rContext )
                {
                    ENSURE_OR_THROW( mpContext,
                                      "ConstantFunctor::ConstantFunctor(): Invalid context" );
                }

                void operator()( StringIteratorT, StringIteratorT ) const
                {
                    mpContext->maOperandStack.push(
                        ExpressionNodeFactory::createConstantValueExpression( mnValue ) );
                }

            private:
                const double            mnValue;
                ParserContextSharedPtr  mpContext;
            };

            /** Generate parse-dependent-but-then-constant value
             */
            class DoubleConstantFunctor
            {
            public:
                explicit DoubleConstantFunctor( const ParserContextSharedPtr& rContext ) :
                    mpContext( rContext )
                {
                    ENSURE_OR_THROW( mpContext,
                                      "DoubleConstantFunctor::DoubleConstantFunctor(): Invalid context" );
                }

                void operator()( double n ) const
                {
                    // push constant value expression to the stack
                    mpContext->maOperandStack.push(
                        ExpressionNodeFactory::createConstantValueExpression( n ) );
                }

            private:
                ParserContextSharedPtr  mpContext;
            };

            /** Generate special t value expression node
             */
            class ValueTFunctor
            {
            public:
                explicit ValueTFunctor( const ParserContextSharedPtr& rContext ) :
                    mpContext( rContext )
                {
                    ENSURE_OR_THROW( mpContext,
                                      "ValueTFunctor::ValueTFunctor(): Invalid context" );
                }

                void operator()( StringIteratorT, StringIteratorT ) const
                {
                    if( !mpContext->mbParseAnimationFunction )
                    {
                        SAL_WARN("slideshow", "ValueTFunctor::operator(): variable encountered, but we're not parsing a function here" );
                        throw ParseError();
                    }

                    // push special t value expression to the stack
                    mpContext->maOperandStack.push(
                        ExpressionNodeFactory::createValueTExpression() );
                }

            private:
                ParserContextSharedPtr  mpContext;
            };

            template< typename Functor > class UnaryFunctionFunctor
            {
            private:
                /** ExpressionNode implementation for unary
                    function over one ExpressionNode
                 */
                class UnaryFunctionExpression : public ExpressionNode
                {
                public:
                    UnaryFunctionExpression( const Functor&                 rFunctor,
<--- Class 'UnaryFunctionExpression' has a constructor with 1 argument that is not explicit. [+]
Class 'UnaryFunctionExpression' has a constructor with 1 argument that is not explicit. Such constructors should in general be explicit for type safety reasons. Using the explicit keyword in the constructor means some mistakes when using the class can be avoided.
                                             const std::shared_ptr<ExpressionNode>& rArg ) :
                        maFunctor( rFunctor ),
                        mpArg( rArg )
                    {
                    }

                    virtual double operator()( double t ) const override
                    {
                        return maFunctor( (*mpArg)(t) );
                    }

                    virtual bool isConstant() const override
                    {
                        return mpArg->isConstant();
                    }

                private:
                    Functor                 maFunctor;
                    std::shared_ptr<ExpressionNode> mpArg;
                };

            public:
                UnaryFunctionFunctor( const Functor&                rFunctor,
<--- Class 'UnaryFunctionFunctor < double ( * ) ( double ) >' has a constructor with 1 argument that is not explicit. [+]
Class 'UnaryFunctionFunctor < double ( * ) ( double ) >' has a constructor with 1 argument that is not explicit. Such constructors should in general be explicit for type safety reasons. Using the explicit keyword in the constructor means some mistakes when using the class can be avoided.
                                      const ParserContextSharedPtr& rContext ) :
                    maFunctor( rFunctor ),
                    mpContext( rContext )
                {
                    ENSURE_OR_THROW( mpContext,
                                      "UnaryFunctionFunctor::UnaryFunctionFunctor(): Invalid context" );
                }

                void operator()( StringIteratorT, StringIteratorT ) const
                {
                    ParserContext::OperandStack& rNodeStack( mpContext->maOperandStack );

                    if( rNodeStack.empty() )
                        throw ParseError( "Not enough arguments for unary operator" );

                    // retrieve arguments
                    std::shared_ptr<ExpressionNode> pArg( std::move(rNodeStack.top()) );
                    rNodeStack.pop();

                    // check for constness
                    if( pArg->isConstant() )
                    {
                        rNodeStack.push(
                            ExpressionNodeFactory::createConstantValueExpression(
                                maFunctor( (*pArg)(0.0) ) ) );
                    }
                    else
                    {
                        // push complex node, that calcs the value on demand
                        rNodeStack.push(
                            std::make_shared<UnaryFunctionExpression>(
                                    maFunctor,
                                    pArg ) );
                    }
                }

            private:
                Functor                 maFunctor;
                ParserContextSharedPtr  mpContext;
            };

            // TODO(Q2): Refactor makeUnaryFunctionFunctor,
            // makeBinaryFunctionFunctor and the whole
            // ExpressionNodeFactory, to use a generic
            // makeFunctionFunctor template, which is overloaded for
            // unary, binary, ternary, etc. function pointers.
            template< typename Functor > UnaryFunctionFunctor<Functor>
                makeUnaryFunctionFunctor( const Functor&                rFunctor,
                                          const ParserContextSharedPtr& rContext )
            {
                return UnaryFunctionFunctor<Functor>( rFunctor, rContext );
            }

            // MSVC has problems instantiating above template function with plain function
            // pointers (doesn't like the const reference there). Thus, provide it with
            // a dedicated overload here.
            UnaryFunctionFunctor< double (*)(double) >
                makeUnaryFunctionFunctor( double (*pFunc)(double),<--- The function 'makeUnaryFunctionFunctor' is never used.
                                          const ParserContextSharedPtr& rContext )
            {
                return UnaryFunctionFunctor< double (*)(double) >( pFunc, rContext );
            }

            /** Implements a binary function over two ExpressionNodes

                @tpl Generator
                Generator functor, to generate an ExpressionNode of
                appropriate type

             */
            template< class Generator > class BinaryFunctionFunctor
            {
            public:
                BinaryFunctionFunctor( const Generator&                 rGenerator,
                                       const ParserContextSharedPtr&    rContext ) :
                    maGenerator( rGenerator ),
                    mpContext( rContext )
                {
                    ENSURE_OR_THROW( mpContext,
                                      "BinaryFunctionFunctor::BinaryFunctionFunctor(): Invalid context" );
                }

                void operator()( StringIteratorT, StringIteratorT ) const
                {
                    ParserContext::OperandStack& rNodeStack( mpContext->maOperandStack );

                    if( rNodeStack.size() < 2 )
                        throw ParseError( "Not enough arguments for binary operator" );

                    // retrieve arguments
                    std::shared_ptr<ExpressionNode> pSecondArg( std::move(rNodeStack.top()) );
                    rNodeStack.pop();
                    std::shared_ptr<ExpressionNode> pFirstArg( std::move(rNodeStack.top()) );
                    rNodeStack.pop();

                    // create combined ExpressionNode
                    std::shared_ptr<ExpressionNode> pNode( maGenerator( pFirstArg,
                                                                pSecondArg ) );
                    // check for constness
                    if( pFirstArg->isConstant() &&
                        pSecondArg->isConstant() )
                    {
                        // call the operator() at pNode, store result
                        // in constant value ExpressionNode.
                        rNodeStack.push(
                            ExpressionNodeFactory::createConstantValueExpression(
                                (*pNode)( 0.0 ) ) );
                    }
                    else
                    {
                        // push complex node, that calcs the value on demand
                        rNodeStack.push( pNode );
                    }
                }

            private:
                Generator               maGenerator;
                ParserContextSharedPtr  mpContext;
            };

            template< typename Generator > BinaryFunctionFunctor<Generator>
                makeBinaryFunctionFunctor( const Generator&                 rGenerator,
                                           const ParserContextSharedPtr&    rContext )
            {
                return BinaryFunctionFunctor<Generator>( rGenerator, rContext );
            }


            // Workaround for MSVC compiler anomaly (stack trashing)

            // The default ureal_parser_policies implementation of parse_exp
            // triggers a really weird error in MSVC7 (Version 13.00.9466), in
            // that the real_parser_impl::parse_main() call of parse_exp()
            // overwrites the frame pointer _on the stack_ (EBP of the calling
            // function gets overwritten while lying on the stack).

            // For the time being, our parser thus can only read the 1.0E10
            // notation, not the 1.0e10 one.

            // TODO(F1): Also handle the 1.0e10 case here.
            template< typename T > struct custom_real_parser_policies : public ::boost::spirit::classic::ureal_parser_policies<T>
            {
                template< typename ScannerT >
                    static typename ::boost::spirit::classic::parser_result< ::boost::spirit::classic::chlit<>, ScannerT >::type
                parse_exp(ScannerT& scan)
                {
                    // as_lower_d somehow breaks MSVC7
                    return ::boost::spirit::classic::ch_p('E').parse(scan);
                }
            };

            /* This class implements the following grammar (more or
               less literally written down below, only slightly
               obfuscated by the parser actions):

               identifier = '$'|'pi'|'e'|'X'|'Y'|'Width'|'Height'

               function = 'abs'|'sqrt'|'sin'|'cos'|'tan'|'atan'|'acos'|'asin'|'exp'|'log'

               basic_expression =
                                number |
                                identifier |
                                function '(' additive_expression ')' |
                                '(' additive_expression ')'

               unary_expression =
                                   '-' basic_expression |
                                basic_expression

               multiplicative_expression =
                                   unary_expression ( ( '*' unary_expression )* |
                                                   ( '/' unary_expression )* )

               additive_expression =
                                   multiplicative_expression ( ( '+' multiplicative_expression )* |
                                                               ( '-' multiplicative_expression )* )

             */
            class ExpressionGrammar : public ::boost::spirit::classic::grammar< ExpressionGrammar >
            {
            public:
                /** Create an arithmetic expression grammar

                    @param rParserContext
                    Contains context info for the parser
                 */
                explicit ExpressionGrammar( const ParserContextSharedPtr& rParserContext ) :
                    mpParserContext( rParserContext )
                {
                }

                template< typename ScannerT > class definition
                {
                public:
                    // grammar definition
                    explicit definition( const ExpressionGrammar& self )
                    {
                        using ::boost::spirit::classic::str_p;
                        using ::boost::spirit::classic::real_parser;

                        identifier =
                                    str_p( "$"      )[ ValueTFunctor(                                                              self.getContext()) ]
                              |     str_p( "pi"     )[ ConstantFunctor(M_PI,                                                       self.getContext()) ]
                              |     str_p( "e"      )[ ConstantFunctor(M_E,                                                        self.getContext()) ]
                              |     str_p( "x"      )[ makeShapeBoundsFunctor(::std::mem_fn(&::basegfx::B2DRange::getCenterX),self.getContext()) ]
                              |     str_p( "y"      )[ makeShapeBoundsFunctor(::std::mem_fn(&::basegfx::B2DRange::getCenterY),self.getContext()) ]
                              |     str_p( "width"  )[ makeShapeBoundsFunctor(::std::mem_fn(&::basegfx::B2DRange::getWidth),  self.getContext()) ]
                              |     str_p( "height" )[ makeShapeBoundsFunctor(::std::mem_fn(&::basegfx::B2DRange::getHeight), self.getContext()) ]
                              ;

                        unaryFunction =
                                (str_p( "abs"  ) >> '(' >> additiveExpression >> ')' )[ makeUnaryFunctionFunctor(&fabs, self.getContext()) ]
                            |   (str_p( "sqrt" ) >> '(' >> additiveExpression >> ')' )[ makeUnaryFunctionFunctor(&sqrt, self.getContext()) ]
                            |   (str_p( "sin"  ) >> '(' >> additiveExpression >> ')' )[ makeUnaryFunctionFunctor(&sin,  self.getContext()) ]
                            |   (str_p( "cos"  ) >> '(' >> additiveExpression >> ')' )[ makeUnaryFunctionFunctor(&cos,  self.getContext()) ]
                            |   (str_p( "tan"  ) >> '(' >> additiveExpression >> ')' )[ makeUnaryFunctionFunctor(&tan,  self.getContext()) ]
                            |   (str_p( "atan" ) >> '(' >> additiveExpression >> ')' )[ makeUnaryFunctionFunctor(&atan, self.getContext()) ]
                            |   (str_p( "acos" ) >> '(' >> additiveExpression >> ')' )[ makeUnaryFunctionFunctor(&acos, self.getContext()) ]
                            |   (str_p( "asin" ) >> '(' >> additiveExpression >> ')' )[ makeUnaryFunctionFunctor(&asin, self.getContext()) ]
                            |   (str_p( "exp"  ) >> '(' >> additiveExpression >> ')' )[ makeUnaryFunctionFunctor(&exp,  self.getContext()) ]
                            |   (str_p( "log"  ) >> '(' >> additiveExpression >> ')' )[ makeUnaryFunctionFunctor(&log,  self.getContext()) ]
                            ;

                        binaryFunction =
                                (str_p( "min"  ) >> '(' >> additiveExpression >> ',' >> additiveExpression >> ')' )[ makeBinaryFunctionFunctor(&ExpressionNodeFactory::createMinExpression, self.getContext()) ]
                            |   (str_p( "max"  ) >> '(' >> additiveExpression >> ',' >> additiveExpression >> ')' )[ makeBinaryFunctionFunctor(&ExpressionNodeFactory::createMaxExpression, self.getContext()) ]
                            ;

                        basicExpression =
                                real_parser<double, custom_real_parser_policies<double> >()[ DoubleConstantFunctor(self.getContext()) ]
                            |   identifier
                            |   unaryFunction
                            |   binaryFunction
                            |   '(' >> additiveExpression >> ')'
                            ;

                        unaryExpression =
                                ('-' >> basicExpression)[ makeUnaryFunctionFunctor(::std::negate<double>(), self.getContext()) ]
                            |   basicExpression
                            ;

                        multiplicativeExpression =
                                unaryExpression
                            >> *( ('*' >> unaryExpression)[ makeBinaryFunctionFunctor(&ExpressionNodeFactory::createMultipliesExpression, self.getContext()) ]
                                | ('/' >> unaryExpression)[ makeBinaryFunctionFunctor(&ExpressionNodeFactory::createDividesExpression,    self.getContext()) ]
                                )
                            ;

                        additiveExpression =
                                multiplicativeExpression
                            >> *( ('+' >> multiplicativeExpression)[ makeBinaryFunctionFunctor(&ExpressionNodeFactory::createPlusExpression,  self.getContext()) ]
                                | ('-' >> multiplicativeExpression)[ makeBinaryFunctionFunctor(&ExpressionNodeFactory::createMinusExpression, self.getContext()) ]
                                )
                            ;

                        BOOST_SPIRIT_DEBUG_RULE(additiveExpression);
                        BOOST_SPIRIT_DEBUG_RULE(multiplicativeExpression);
                        BOOST_SPIRIT_DEBUG_RULE(unaryExpression);
                        BOOST_SPIRIT_DEBUG_RULE(basicExpression);
                        BOOST_SPIRIT_DEBUG_RULE(unaryFunction);
                        BOOST_SPIRIT_DEBUG_RULE(binaryFunction);
                        BOOST_SPIRIT_DEBUG_RULE(identifier);
                    }

                    const ::boost::spirit::classic::rule< ScannerT >& start() const
                    {
                        return additiveExpression;
                    }

                private:
                    // the constituents of the Spirit arithmetic expression grammar.
                    // For the sake of readability, without 'ma' prefix.
                    ::boost::spirit::classic::rule< ScannerT >   additiveExpression;
                    ::boost::spirit::classic::rule< ScannerT >   multiplicativeExpression;
                    ::boost::spirit::classic::rule< ScannerT >   unaryExpression;
                    ::boost::spirit::classic::rule< ScannerT >   basicExpression;
                    ::boost::spirit::classic::rule< ScannerT >   unaryFunction;
                    ::boost::spirit::classic::rule< ScannerT >   binaryFunction;
                    ::boost::spirit::classic::rule< ScannerT >   identifier;
                };

                const ParserContextSharedPtr& getContext() const
                {
                    return mpParserContext;
                }

            private:
                ParserContextSharedPtr  mpParserContext; // might get modified during parsing
            };

            const ParserContextSharedPtr& getParserContext()
            {
                static ParserContextSharedPtr lcl_parserContext = std::make_shared<ParserContext>();

                // clear node stack (since we reuse the static object, that's
                // the whole point here)
                while( !lcl_parserContext->maOperandStack.empty() )
                    lcl_parserContext->maOperandStack.pop();

                return lcl_parserContext;
            }
        }

        std::shared_ptr<ExpressionNode> const & SmilFunctionParser::parseSmilValue( const OUString&          rSmilValue,
                                                                    const ::basegfx::B2DRectangle&  rRelativeShapeBounds )
        {
            // TODO(Q1): Check if a combination of the RTL_UNICODETOTEXT_FLAGS_*
            // gives better conversion robustness here (we might want to map space
            // etc. to ASCII space here)
            const OString& rAsciiSmilValue(
                OUStringToOString( rSmilValue, RTL_TEXTENCODING_ASCII_US ) );

            StringIteratorT aStart( rAsciiSmilValue.getStr() );
            StringIteratorT aEnd( rAsciiSmilValue.getStr()+rAsciiSmilValue.getLength() );

            // static parser context, because the actual
            // Spirit parser is also a static object
            ParserContextSharedPtr pContext = getParserContext();

            pContext->maShapeBounds = rRelativeShapeBounds;
            pContext->mbParseAnimationFunction = false; // parse with '$' disabled


            ExpressionGrammar aExpressionGrammer( pContext );
            const ::boost::spirit::classic::parse_info<StringIteratorT> aParseInfo(
                  ::boost::spirit::classic::parse( aStart,
                                          aEnd,
                                          aExpressionGrammer,
                                          ::boost::spirit::classic::space_p ) );

#if OSL_DEBUG_LEVEL > 0
            ::std::cout.flush(); // needed to keep stdout and cout in sync
#endif

            // input fully congested by the parser?
            if( !aParseInfo.full )
                throw ParseError( "SmilFunctionParser::parseSmilValue(): string not fully parseable" );

            // parser's state stack now must contain exactly _one_ ExpressionNode,
            // which represents our formula.
            if( pContext->maOperandStack.size() != 1 )
                throw ParseError( "SmilFunctionParser::parseSmilValue(): incomplete or empty expression" );

            return pContext->maOperandStack.top();
        }

        std::shared_ptr<ExpressionNode> const & SmilFunctionParser::parseSmilFunction( const OUString&           rSmilFunction,
                                                                       const ::basegfx::B2DRectangle&   rRelativeShapeBounds )
        {
            // TODO(Q1): Check if a combination of the RTL_UNICODETOTEXT_FLAGS_*
            // gives better conversion robustness here (we might want to map space
            // etc. to ASCII space here)
            const OString& rAsciiSmilFunction(
                OUStringToOString( rSmilFunction, RTL_TEXTENCODING_ASCII_US ) );

            StringIteratorT aStart( rAsciiSmilFunction.getStr() );
            StringIteratorT aEnd( rAsciiSmilFunction.getStr()+rAsciiSmilFunction.getLength() );

            // static parser context, because the actual
            // Spirit parser is also a static object
            ParserContextSharedPtr pContext = getParserContext();

            pContext->maShapeBounds = rRelativeShapeBounds;
            pContext->mbParseAnimationFunction = true; // parse with '$' enabled


            ExpressionGrammar aExpressionGrammer( pContext );
            const ::boost::spirit::classic::parse_info<StringIteratorT> aParseInfo(
                  ::boost::spirit::classic::parse( aStart,
                                          aEnd,
                                          aExpressionGrammer >> ::boost::spirit::classic::end_p,
                                          ::boost::spirit::classic::space_p ) );

#if OSL_DEBUG_LEVEL > 0
            ::std::cout.flush(); // needed to keep stdout and cout in sync
#endif
            // input fully congested by the parser?
            if( !aParseInfo.full )
                throw ParseError( "SmilFunctionParser::parseSmilFunction(): string not fully parseable" );

            // parser's state stack now must contain exactly _one_ ExpressionNode,
            // which represents our formula.
            if( pContext->maOperandStack.size() != 1 )
                throw ParseError( "SmilFunctionParser::parseSmilFunction(): incomplete or empty expression" );

            return pContext->maOperandStack.top();
        }
}

#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)

// debug hooks

namespace boost
{

void sp_scalar_constructor_hook(void *)<--- The function 'sp_scalar_constructor_hook' is never used.
{
}

void sp_scalar_destructor_hook(void *)<--- The function 'sp_scalar_destructor_hook' is never used.
{
}

}

#endif

/* vim:set shiftwidth=4 softtabstop=4 expandtab: */