WordPress/AbstractFunctionRestrictionsSniff.php
public function is_targetted_token( $stackPtr ) {

		// Exclude function definitions, class methods, and namespaced calls.
		if ( \T_STRING === $this->tokens[ $stackPtr ]['code'] ) {
			if ( $this->is_class_object_call( $stackPtr ) === true ) {
				return false;
			}

			if ( $this->is_token_namespaced( $stackPtr ) === true ) {
				return false;
			}

			$prev = $this->phpcsFile->findPrevious( Tokens::$emptyTokens, ( $stackPtr - 1 ), null, true );

			if ( false !== $prev ) {
				// Skip sniffing if calling a same-named method, or on function definitions.
				$skipped = array(
					\T_FUNCTION        => \T_FUNCTION,
					\T_CLASS           => \T_CLASS,
					\T_AS              => \T_AS, // Use declaration alias.
				);

				if ( isset( $skipped[ $this->tokens[ $prev ]['code'] ] ) ) {
					return false;
				}
			}

			return true;
		}

		return false;
	}
public function is_targetted_token( $stackPtr ) {

		// Exclude function definitions, class methods, and namespaced calls.
		if ( \T_STRING === $this->tokens[ $stackPtr ]['code'] ) {
			if ( $this->is_class_object_call( $stackPtr ) === true ) {
				return false;
			}

			if ( $this->is_token_namespaced( $stackPtr ) === true ) {
				return false;
			}

			$prev = $this->phpcsFile->findPrevious( Tokens::$emptyTokens, ( $stackPtr - 1 ), null, true );

			if ( false !== $prev ) {
				// Skip sniffing if calling a same-named method, or on function definitions.
				$skipped = array(
					\T_FUNCTION        => \T_FUNCTION,
					\T_CLASS           => \T_CLASS,
					\T_AS              => \T_AS, // Use declaration alias.
				);

				if ( isset( $skipped[ $this->tokens[ $prev ]['code'] ] ) ) {
					return false;
				}
			}

			return true;
		}

		return false;
	}
Verify is the current token is a function call.

@since 0.11.0 Split out from the `process()` method.

@param int $stackPtr The position of the current token in the stack.

@return bool