Checks whether a call to the size()/length() method can be replaced with a call to empty(). More...

#include <ContainerSizeEmptyCheck.h>

Inheritance diagram for clang::tidy::readability::ContainerSizeEmptyCheck:

Public Member Functions
	ContainerSizeEmptyCheck (StringRef Name, ClangTidyContext *Context)

bool	isLanguageVersionSupported (const LangOptions &LangOpts) const override
	Override this to disable registering matchers and PP callbacks if an invalid language version is being used.

void	registerMatchers (ast_matchers::MatchFinder *Finder) override
	Override this to register AST matchers with `Finder`.

void	check (const ast_matchers::MatchFinder::MatchResult &Result) override
	`ClangTidyChecks` that register ASTMatchers should do the actual work in here.

void	storeOptions (ClangTidyOptions::OptionMap &Opts) override
	Should store all options supported by this check with their current values or default values for options that haven't been overridden.

std::optional< TraversalKind >	getCheckTraversalKind () const override

Public Member Functions inherited from clang::tidy::ClangTidyCheck
	ClangTidyCheck (StringRef CheckName, ClangTidyContext *Context)
	Initializes the check with `CheckName` and `Context`.

virtual bool	isLanguageVersionSupported (const LangOptions &LangOpts) const
	Override this to disable registering matchers and PP callbacks if an invalid language version is being used.

virtual void	registerPPCallbacks (const SourceManager &SM, Preprocessor PP, Preprocessor ModuleExpanderPP)
	Override this to register `PPCallbacks` in the preprocessor.

virtual void	registerMatchers (ast_matchers::MatchFinder *Finder)
	Override this to register AST matchers with `Finder`.

virtual void	check (const ast_matchers::MatchFinder::MatchResult &Result)
	`ClangTidyChecks` that register ASTMatchers should do the actual work in here.

DiagnosticBuilder	diag (SourceLocation Loc, StringRef Description, DiagnosticIDs::Level Level=DiagnosticIDs::Warning)
	Add a diagnostic with the check's name.

DiagnosticBuilder	diag (StringRef Description, DiagnosticIDs::Level Level=DiagnosticIDs::Warning)
	Add a diagnostic with the check's name.

DiagnosticBuilder	configurationDiag (StringRef Description, DiagnosticIDs::Level Level=DiagnosticIDs::Warning) const
	Adds a diagnostic to report errors in the check's configuration.

virtual void	storeOptions (ClangTidyOptions::OptionMap &Options)
	Should store all options supported by this check with their current values or default values for options that haven't been overridden.

Additional Inherited Members
Protected Member Functions inherited from clang::tidy::ClangTidyCheck
StringRef	getCurrentMainFile () const
	Returns the main file name of the current translation unit.

const LangOptions &	getLangOpts () const
	Returns the language options from the context.

bool	areDiagsSelfContained () const
	Returns true when the check is run in a use case when only 1 fix will be applied at a time.

StringRef	getID () const override

Protected Attributes inherited from clang::tidy::ClangTidyCheck
OptionsView	Options

Detailed Description

Checks whether a call to the size()/length() method can be replaced with a call to empty().

The emptiness of a container should be checked using the empty() method instead of the size() method. It is not guaranteed that size() is a constant-time function, and it is generally more efficient and also shows clearer intent to use empty(). Furthermore some containers may implement the empty() method but not implement the size() method. Using empty() whenever possible makes it easier to switch to another container in the future.

Definition at line 27 of file ContainerSizeEmptyCheck.h.

Constructor & Destructor Documentation

◆ ContainerSizeEmptyCheck()

clang::tidy::readability::ContainerSizeEmptyCheck::ContainerSizeEmptyCheck	(	StringRef	Name,
		ClangTidyContext *	Context
	)

Definition at line 115 of file ContainerSizeEmptyCheck.cpp.

Member Function Documentation

◆ check()

void clang::tidy::readability::ContainerSizeEmptyCheck::check ( const ast_matchers::MatchFinder::MatchResult & Result )

overridevirtual

ClangTidyChecks that register ASTMatchers should do the actual work in here.

Reimplemented from clang::tidy::ClangTidyCheck.

Definition at line 224 of file ContainerSizeEmptyCheck.cpp.

References Container, clang::tidy::ClangTidyCheck::diag(), E, and clang::tidy::ClangTidyCheck::getLangOpts().

◆ getCheckTraversalKind()

std::optional< TraversalKind > clang::tidy::readability::ContainerSizeEmptyCheck::getCheckTraversalKind ( ) const

inlineoverride

Definition at line 36 of file ContainerSizeEmptyCheck.h.

◆ isLanguageVersionSupported()

bool clang::tidy::readability::ContainerSizeEmptyCheck::isLanguageVersionSupported ( const LangOptions & LangOpts ) const

inlineoverridevirtual

Override this to disable registering matchers and PP callbacks if an invalid language version is being used.

For example if a check is examining overloaded functions then this should be overridden to return false when the CPlusPlus flag is not set in LangOpts.

Reimplemented from clang::tidy::ClangTidyCheck.

Definition at line 30 of file ContainerSizeEmptyCheck.h.

◆ registerMatchers()

void clang::tidy::readability::ContainerSizeEmptyCheck::registerMatchers ( ast_matchers::MatchFinder * Finder )

overridevirtual

Override this to register AST matchers with Finder.

This should be used by clang-tidy checks that analyze code properties that dependent on AST knowledge.

You can register as many matchers as necessary with Finder. Usually, "this" will be used as callback, but you can also specify other callback classes. Thereby, different matchers can trigger different callbacks.

This will only be executed if the function isLanguageVersionSupported returns true.

If you need to merge information between the different matchers, you can store these as members of the derived class. However, note that all matches occur in the order of the AST traversal.

Reimplemented from clang::tidy::ClangTidyCheck.

Definition at line 126 of file ContainerSizeEmptyCheck.cpp.

References clang::tidy::matchers::matchesAnyListedName().