genode/repos/os/src/server/report_rom
Norman Feske eba9c15746 Follow practices suggested by "Effective C++"
The patch adjust the code of the base, base-<kernel>, and os repository.
To adapt existing components to fix violations of the best practices
suggested by "Effective C++" as reported by the -Weffc++ compiler
argument. The changes follow the patterns outlined below:

* A class with virtual functions can no longer publicly inherit base
  classed without a vtable. The inherited object may either be moved
  to a member variable, or inherited privately. The latter would be
  used for classes that inherit 'List::Element' or 'Avl_node'. In order
  to enable the 'List' and 'Avl_tree' to access the meta data, the
  'List' must become a friend.

* Instead of adding a virtual destructor to abstract base classes,
  we inherit the new 'Interface' class, which contains a virtual
  destructor. This way, single-line abstract base classes can stay
  as compact as they are now. The 'Interface' utility resides in
  base/include/util/interface.h.

* With the new warnings enabled, all member variables must be explicitly
  initialized. Basic types may be initialized with '='. All other types
  are initialized with braces '{ ... }' or as class initializers. If
  basic types and non-basic types appear in a row, it is nice to only
  use the brace syntax (also for basic types) and align the braces.

* If a class contains pointers as members, it must now also provide a
  copy constructor and assignment operator. In the most cases, one
  would make them private, effectively disallowing the objects to be
  copied. Unfortunately, this warning cannot be fixed be inheriting
  our existing 'Noncopyable' class (the compiler fails to detect that
  the inheriting class cannot be copied and still gives the error).
  For now, we have to manually add declarations for both the copy
  constructor and assignment operator as private class members. Those
  declarations should be prepended with a comment like this:

        /*
         * Noncopyable
         */
        Thread(Thread const &);
        Thread &operator = (Thread const &);

  In the future, we should revisit these places and try to replace
  the pointers with references. In the presence of at least one
  reference member, the compiler would no longer implicitly generate
  a copy constructor. So we could remove the manual declaration.

Issue #465
2018-01-17 12:14:35 +01:00
..
main.cc
README
rom_registry.h Follow practices suggested by "Effective C++" 2018-01-17 12:14:35 +01:00
target.mk

The "report_rom" component is both a report service and a ROM service. It makes
incoming reports available as ROM modules. The ROM modules are named after the
label of the corresponding report session.

Configuration
-------------

The report-ROM server hands out ROM modules only if explicitly permitted by a
configured policy. For example:

! <config>
!   <policy label="decorator -> pointer" report="nitpicker -> pointer"/>
!   <policy ...  />
!   ...
! </config>

The label of an incoming ROM session is matched against the 'label' attribute
of all '<policy>' nodes. If the session label matches a policy label, the
client obtains the data from the report client with the label specified in the
'report' attribute. In the example above, the nitpicker GUI server sends
reports about the pointer position to the report-ROM service. Those reports
are handed out to a window decorator (labeled "decorator") as ROM module.

The component can be configured to write all incoming reports to the LOG
output by setting the 'verbose' attribute of the '<config>' node to "yes".