protected function process_variable_variable( $stackPtr ) {
		static $indicators = array(
			\T_OPEN_CURLY_BRACKET => true,
			\T_VARIABLE           => true,
		);

		// Is this a variable variable ?
		// Not concerned with nested ones as those will be recognized on their own token.
		$next_non_empty = $this->phpcsFile->findNext( Tokens::$emptyTokens, ( $stackPtr + 1 ), null, true, null, true );
		if ( false === $next_non_empty || ! isset( $indicators[ $this->tokens[ $next_non_empty ]['code'] ] ) ) {
			return;
		}

		if ( \T_OPEN_CURLY_BRACKET === $this->tokens[ $next_non_empty ]['code']
			&& isset( $this->tokens[ $next_non_empty ]['bracket_closer'] )
		) {
			// Skip over the variable part.
			$next_non_empty = $this->tokens[ $next_non_empty ]['bracket_closer'];
		}

		$maybe_assignment = $this->phpcsFile->findNext( Tokens::$emptyTokens, ( $next_non_empty + 1 ), null, true, null, true );

		while ( false !== $maybe_assignment
			&& \T_OPEN_SQUARE_BRACKET === $this->tokens[ $maybe_assignment ]['code']
			&& isset( $this->tokens[ $maybe_assignment ]['bracket_closer'] )
		) {
			$maybe_assignment = $this->phpcsFile->findNext(
				Tokens::$emptyTokens,
				( $this->tokens[ $maybe_assignment ]['bracket_closer'] + 1 ),
				null,
				true,
				null,
				true
			);
		}

		if ( false === $maybe_assignment ) {
			return;
		}

		if ( ! isset( Tokens::$assignmentTokens[ $this->tokens[ $maybe_assignment ]['code'] ] ) ) {
			// Not an assignment.
			return;
		}

		$error = self::ERROR_MSG;

		/*
		 * Local variable variables in a function do not need to be prefixed.
		 * But a variable variable could evaluate to the name of an imported global
		 * variable.
		 * Not concerned with imported variable variables (global.. ) as that has been
		 * forbidden since PHP 7.0. Presuming cross-version code and if not, that
		 * is for the PHPCompatibility standard to detect.
		 */
		if ( $this->phpcsFile->hasCondition( $stackPtr, array( \T_FUNCTION, \T_CLOSURE ) ) === true ) {
			$condition = $this->phpcsFile->getCondition( $stackPtr, \T_FUNCTION );
			if ( false === $condition ) {
				$condition = $this->phpcsFile->getCondition( $stackPtr, \T_CLOSURE );
			}

			$has_global = $this->phpcsFile->findPrevious( \T_GLOBAL, ( $stackPtr - 1 ), $this->tokens[ $condition ]['scope_opener'] );
			if ( false === $has_global ) {
				// No variable import happening.
				return;
			}

			$error = 'Variable variable which could potentially override an imported global variable detected. ' . $error;
		}

		$variable_name = $this->phpcsFile->getTokensAsString( $stackPtr, ( ( $next_non_empty - $stackPtr ) + 1 ) );

		// Still here ? In that case, the variable name should be prefixed.
		$recorded = $this->phpcsFile->addWarning(
			$error,
			$stackPtr,
			'NonPrefixedVariableFound',
			array(
				'Global variables defined',
				$variable_name,
			)
		);

		if ( true === $recorded ) {
			$this->record_potential_prefix_metric( $stackPtr, $variable_name );
		}

		// Skip over the variable part of the variable.
		return ( $next_non_empty + 1 );
	}