Cppcheck: FwdAnalysis Class Reference

Cppcheck

Forward data flow analysis for checks. More...

#include <fwdanalysis.h>

Classes
struct	KnownAndToken

struct	Result
	Result of forward analysis. More...

Public Member Functions
	FwdAnalysis (const Settings &settings)

bool	hasOperand (const Token tok, const Token lhs) const

const Token *	reassign (const Token expr, const Token startToken, const Token *endToken)
	Check if "expr" is reassigned. More...

bool	unusedValue (const Token expr, const Token startToken, const Token *endToken)
	Check if "expr" is used. More...

bool	possiblyAliased (const Token expr, const Token startToken) const
	Is there some possible alias for given expression. More...

std::set< nonneg int >	getExprVarIds (const Token expr, bool localOut=nullptr, bool *unknownVarIdOut=nullptr) const

Private Types
enum class	What { Reassign , UnusedValue , ValueFlow }

Private Member Functions
Result	check (const Token expr, const Token startToken, const Token *endToken)

Result	checkRecursive (const Token expr, const Token startToken, const Token *endToken, const std::set< nonneg int > &exprVarIds, bool local, bool inInnerClass, int depth=0)

Static Private Member Functions
static bool	isEscapedAlias (const Token *expr)

Private Attributes
const Settings &	mSettings

enum FwdAnalysis::What	mWhat = What::Reassign

std::vector< KnownAndToken >	mValueFlow

bool	mValueFlowKnown = true

Detailed Description

Forward data flow analysis for checks.

unused value
redundant assignment
valueflow analysis

Definition at line 38 of file fwdanalysis.h.

Member Enumeration Documentation

◆ What

enum FwdAnalysis::What

strongprivate

Enumerator
Reassign
UnusedValue
ValueFlow

Definition at line 86 of file fwdanalysis.h.

Constructor & Destructor Documentation

◆ FwdAnalysis()

FwdAnalysis::FwdAnalysis ( const Settings & settings )

inlineexplicit

Definition at line 40 of file fwdanalysis.h.

Member Function Documentation

◆ check()

FwdAnalysis::Result FwdAnalysis::check	(	const Token *	expr,
		const Token *	startToken,
		const Token *	endToken
	)

private

Definition at line 433 of file fwdanalysis.cpp.

References FwdAnalysis::Result::BAILOUT, FwdAnalysis::Result::BREAK, checkRecursive(), findNextTokenFromBreak(), getExprVarIds(), isGlobalData(), mWhat, Token::next(), Reassign, FwdAnalysis::Result::token, FwdAnalysis::Result::type, UnusedValue, and ValueFlow.

Referenced by reassign(), and unusedValue().

◆ checkRecursive()

FwdAnalysis::Result FwdAnalysis::checkRecursive	(	const Token *	expr,
		const Token *	startToken,
		const Token *	endToken,
		const std::set< nonneg int > &	exprVarIds,
		bool	local,
		bool	inInnerClass,
		int	depth = `0`
	)

private

Definition at line 96 of file fwdanalysis.cpp.

References Library::Function::argumentChecks, Token::astOperand1(), Token::astOperand2(), Token::astParent(), FwdAnalysis::Result::BAILOUT, FwdAnalysis::Result::BREAK, Library::ArgumentChecks::DIR_OUT, Token::eLambda, Token::findExpressionStartEndTokens(), findLambdaEndToken(), findNextTokenFromBreak(), getArguments(), Library::getFunction(), hasFunctionCall(), hasGccCompoundStatement(), Token::hasKnownIntValue(), hasOperand(), Token::isCast(), Token::isName(), isReturnScope(), isSameExpression(), Token::isUnaryOp(), isUnchanged(), FwdAnalysis::KnownAndToken::known, Settings::library, Token::link(), Token::linkAt(), Token::Match(), mSettings, mValueFlow, mValueFlowKnown, mWhat, Token::next(), FwdAnalysis::Result::NONE, None, ValueType::pointer, precedes(), Token::previous(), FwdAnalysis::Result::READ, reassign(), Reassign, ValueType::reference, FwdAnalysis::Result::RETURN, Token::scope(), Token::simpleMatch(), Token::str(), Token::tokAt(), FwdAnalysis::KnownAndToken::token, FwdAnalysis::Result::token, FwdAnalysis::Result::type, UnusedValue, ValueFlow, Token::values(), Token::valueType(), Token::variable(), Token::varId(), and FwdAnalysis::Result::WRITE.

Referenced by check().

◆ getExprVarIds()

std::set< nonneg int > FwdAnalysis::getExprVarIds	(	const Token *	expr,
		bool *	localOut = `nullptr`,
		bool *	unknownVarIdOut = `nullptr`
	)		const

Definition at line 399 of file fwdanalysis.cpp.

References Token::isName(), mWhat, op1, op1_and_op2, Token::previous(), Token::str(), UnusedValue, Token::varId(), and visitAstNodes().

Referenced by check().

◆ hasOperand()

bool FwdAnalysis::hasOperand	(	const Token *	tok,
		const Token *	lhs
	)		const

Definition at line 464 of file fwdanalysis.cpp.

References Token::astOperand1(), Token::astOperand2(), isSameExpression(), and mSettings.

Referenced by checkRecursive(), and CheckOther::checkRedundantAssignment().

◆ isEscapedAlias()

bool FwdAnalysis::isEscapedAlias ( const Token * expr )

staticprivate

Definition at line 550 of file fwdanalysis.cpp.

References Token::astOperand1(), Variable::isArgument(), and Variable::isLocal().

Referenced by unusedValue().

◆ possiblyAliased()

bool FwdAnalysis::possiblyAliased	(	const Token *	expr,
		const Token *	startToken
	)		const

Is there some possible alias for given expression.

Definition at line 495 of file fwdanalysis.cpp.

References Token::astOperand1(), Token::astOperand2(), getArguments(), isSameExpression(), Token::isUnaryOp(), Token::Match(), mSettings, Token::previous(), Token::scope(), Token::simpleMatch(), Token::str(), Token::tokAt(), Token::varId(), and Scope::varlist.

Referenced by unusedValue().

◆ reassign()

const Token * FwdAnalysis::reassign	(	const Token *	expr,
		const Token *	startToken,
		const Token *	endToken
	)

Check if "expr" is reassigned.

The "expr" can be a tree (x.y[12]).

Parameters

expr	Symbolic expression to perform forward analysis for
startToken	First token in forward analysis
endToken	Last token in forward analysis

Returns: Token where expr is reassigned. If it's not reassigned then nullptr is returned.

Definition at line 473 of file fwdanalysis.cpp.

References check(), hasVolatileCastOrVar(), mWhat, Reassign, FwdAnalysis::Result::token, FwdAnalysis::Result::type, and FwdAnalysis::Result::WRITE.

Referenced by checkRecursive(), and CheckOther::checkRedundantAssignment().

◆ unusedValue()

bool FwdAnalysis::unusedValue	(	const Token *	expr,
		const Token *	startToken,
		const Token *	endToken
	)

Check if "expr" is used.

The "expr" can be a tree (x.y[12]).

Parameters

expr	Symbolic expression to perform forward analysis for
startToken	First token in forward analysis
endToken	Last token in forward analysis

Returns: true if expr is used.

Definition at line 482 of file fwdanalysis.cpp.

References astIsContainerView(), Token::astOperand1(), check(), hasVolatileCastOrVar(), isEscapedAlias(), mWhat, FwdAnalysis::Result::NONE, possiblyAliased(), FwdAnalysis::Result::RETURN, Token::simpleMatch(), FwdAnalysis::Result::type, and UnusedValue.

Referenced by CheckUnusedVar::checkFunctionVariableUsage().

Member Data Documentation

◆ mSettings

const Settings& FwdAnalysis::mSettings

private

Definition at line 85 of file fwdanalysis.h.

Referenced by checkRecursive(), hasOperand(), and possiblyAliased().

◆ mValueFlow

std::vector<KnownAndToken> FwdAnalysis::mValueFlow

private

Definition at line 87 of file fwdanalysis.h.

Referenced by checkRecursive().

◆ mValueFlowKnown

bool FwdAnalysis::mValueFlowKnown = true

private

Definition at line 88 of file fwdanalysis.h.

Referenced by checkRecursive().

◆ mWhat

enum FwdAnalysis::What FwdAnalysis::mWhat = What::Reassign

private

Referenced by check(), checkRecursive(), getExprVarIds(), reassign(), and unusedValue().

The documentation for this class was generated from the following files: