Class PreprocessorBranch

A C/C++ preprocessor branching directive: #if, #ifdef, #ifndef, or #elif.

A branching directive has a condition and that condition may be evaluated at compile-time. As a result, the preprocessor will either take the branch, or not take the branch.

However, there are also situations in which a branch’s condition isn’t evaluated. The obvious case of this is when the directive is contained within a branch which wasn’t taken. There is also a much more subtle case involving header guard branches: suitably clever compilers can notice that a branch is a header guard, and can then subsequently ignore a #include for the file being guarded. It is for this reason that wasTaken() always holds on header guard branches, but wasNotToken() rarely holds on header guard branches.

Import path

import cpp

Direct supertypes

Indirect supertypes

Known direct subtypes

Predicates

wasNotTaken	Holds if at least one translation unit evaluated this directive’s condition but then didn’t take the branch.
wasPredictable	Holds if this directive was either taken by all translation units which evaluated it, or was not taken by any translation unit which evaluated it.
wasTaken	Holds if at least one translation unit evaluated this directive’s condition and subsequently took the branch.

Inherited predicates

findRootCause	Gets the source of this element: either itself or a macro that expanded to this element.	from Element
fromSource	Holds if this element may be from source. This predicate holds for all elements, except for those in the dummy file, whose name is the empty string. The dummy file contains declarations that are built directly into the compiler.	from Element
getAGuard	Gets a preprocessor branching directive whose condition affects whether this directive is performed.	from PreprocessorDirective
getAPrimaryQlClass	Gets the name of a primary CodeQL class to which this element belongs.	from ElementBase
getEnclosingElement	Gets the closest `Element` enclosing this one.	from Element
getEndIf	Gets the `#endif` directive which matches this branching directive.	from PreprocessorBranchDirective
getFile	Gets the primary file where this element occurs.	from Element
getHead		from PreprocessorDirective
getIf	Gets the `#if`, `#ifdef` or `#ifndef` directive which matches this branching directive.	from PreprocessorBranchDirective
getLocation	Gets the primary location of this element.	from PreprocessorDirective
getNext	Gets the next `#elif`, `#else` or `#endif` matching this branching directive.	from PreprocessorBranchDirective
getParentScope	Gets the parent scope of this `Element`, if any. A scope is a `Type` (`Class` / `Enum`), a `Namespace`, a `BlockStmt`, a `Function`, or certain kinds of `Statement`.	from Element
getPrimaryQlClasses	Gets a comma-separated list of the names of the primary CodeQL classes to which this element belongs.	from ElementBase
isAffectedByMacro	Holds if this element is affected in any way by a macro. All elements that are totally or partially generated by a macro are included, so this is a super-set of `isInMacroExpansion`.	from Element
isFromTemplateInstantiation	Holds if this `Element` is a part of a template instantiation (but not the template itself).	from Element
isFromUninstantiatedTemplate	Holds if this `Element` is part of a template `template` (not if it is part of an instantiation of `template`). This means it is represented in the database purely as syntax and without guarantees on the presence or correctness of type-based operations such as implicit conversions.	from Element
isInMacroExpansion	Holds if this element comes from a macro expansion. Only elements that are entirely generated by a macro are included - for elements that partially come from a macro, see `isAffectedByMacro`.	from Element
toString	Gets a textual representation of this element.	from PreprocessorDirective