Piotr Tworek 80e8cf99e2 base: Make Genode::List clang friendly.
Clang is generally fine with Genode::List and compiles code using it
without emitting any warnings. There is however one exception. Clang
fails hard when building base-hw/src/core/kernel/object.cc.
This is due to a call to Genode::List::remove made from
Object_identity::invalidate function. The error message clang
produces is:

  list.h:96:33: error: 'Genode::List<Kernel::Object_identity_reference>::Element::_next'
  is not a member of class 'const Kernel::Object_identity'
                              _first = le->List::Element::_next;
                                           ~~~~~~~~~~~~~~~^

When we look at the declaration of the Kernel::Object class on which
the remove method is called. as expected it does inherit Genode::List:

using Object_identity_list
	= Genode::List<Kernel::Object_identity>;

class Kernel::Object : private Object_identity_list
{
...
}

Given the error message we see that List::Element should be resolved to
Genode::List<Kernel::Object_identity>::Element, and not
Genode::List<Kernel::Object_identity_reference>::Element. But how does
clang manage to figure out we're talking about Object_identity_refecence
list here? Well, I admit I don't know the exact steps it takes to arrive
at this conclusion, but it is not entirely wrong. If we take a look at
what Kernel::Object_identity is we'll see:

class Kernel::Object_identity
: public Object_identity_list::Element,
  public Kernel::Object_identity_reference_list
{
...
}

Where as one can guess Object_identity_reference_list is defined as:

using Object_identity_reference_list
	= Genode::List<Object_identity_reference>;

Long story short Kernel::Object has Genode::List of both Kernel::Object_identity
and Kernel::Object_identity_reference in its inheritance chain and clang
is not really sure to which of those the code refers to in
Genode::List::remove method by using List::Element::.

The fix for this is relatively simple, explicitly state the full type of
the base class the code intends to refer to. Replacing List::Element,
with List<LT>::Element makes the code buildable with both clang and GCC.

Fixes #3990
2021-01-25 13:58:10 +01:00
..
2020-12-18 09:10:52 +01:00
2020-12-18 09:10:52 +01:00
2021-01-25 13:58:10 +01:00
2020-08-25 11:49:44 +02:00

                      ===============================
                      Genode source-code repositories
                      ===============================


This directory contains the source-code repositories of the Genode OS
Framework. Each sub directory has the same principle layout as described in the
build-system manual:

:Build-system manual:

  [https://genode.org/documentation/developer-resources/build_system]

The build system uses a configurable selection of those reposities to obtain
the source codes for the build process. The repositories are not independent
but build upon of each other:

:'base':

  This directory contains the source-code repository of the fundamental
  frameworks and interfaces of Genode. Furthermore, it contains the generic
  parts of core.

:'base-<platform>':
  These directories contain platform-specific source-code repositories
  complementing the 'base' repository. The following platforms are supported:

  :'linux':
    Linux kernel (both x86_32 and x86_64)

  :'nova':
    NOVA hypervisor developed at University of Technology Dresden
    See [https://genode.org/documentation/platforms/nova]

  :'foc':
    Fiasco.OC is a modernized version of the Fiasco microkernel with a
    completely revised kernel interface fostering capability-based
    security. It is not compatible with L4/Fiasco.
    See [https://genode.org/documentation/platforms/foc]

  :'hw':
    The hw platform allows the execution of Genode on bare ARM and x86 hardware
    without the need for a separate kernel. The kernel functionality is
    included in core except in the special case of the Muen separation
    kernel.
    See [https://genode.org/documentation/platforms/hw] and
    [https://genode.org/documentation/platforms/muen]

  :'okl4':
    OKL4 kernel (x86_32 and ARM) developed at Open-Kernel-Labs.
    See [https://genode.org/documentation/platforms/okl4]

  :'pistachio':
    L4ka::Pistachio kernel developed at University of Karlsruhe.
    See [https://genode.org/documentation/platforms/pistachio]

  :'fiasco':
    L4/Fiasco kernel developed at University of Technology Dresden.
    See [https://genode.org/documentation/platforms/fiasco]

  :'sel4':
    seL4 microkernel developed at NICTA/General Dynamics
    See[https://sel4.systems/]

:'os':

  This directory contains the non-base OS components such as the init process,
  device drivers, and basic system services.

:'demo':

  This directory contains the source-code repository of various services and
  applications that we use for demonstration purposes. For example, a graphical
  application launcher called Launchpad and the Scout tutorial browser.

:'hello_tutorial':

  Tutorial for creating a simple client-server scenario with Genode. This
  repository includes documentation and the complete source code.

:'libports':

  This source-code repository contains ports of popular open-source libraries
  to Genode, most importantly the C library. The repository contains no
  upstream source code but means to download the code and adapt it to Genode.
  For instructions about how to use this mechanism, please consult the README
  file at the top level of the repository. Among the 3rd-party libraries
  are Qt5, libSDL, freetype, Python, ncurses, Mesa, and libav.

:'dde_linux':

  This source-code repository contains the device driver environment for
  executing Linux device drivers natively on Genode. Currently, this
  repository hosts the USB stack.

:'dde_ipxe':

  This source-code repository contains the device-driver environment for
  executing drivers of the iPXE project.

:'dde_bsd':

  This source-code repository contains the device-driver environment for
  drivers of the OpenBSD operating system.

:'dde_rump':

  This source-code repository contains the port of rump kernels, which are
  used to execute subsystems of the NetBSD kernel as user level processes.
  The repository contains a server that uses a rump kernel to provide
  various NetBSD file systems to Genode.

:'ports':

  This source-code repository hosts ports of 3rd-party applications to
  Genode. The repository does not contain upstream source code but provides
  a mechanism for downloading the official source distributions and adapt
  them to the Genode environment. The used mechanism is roughly the same
  as used for the 'libports' repository. Please consult 'libports/README'
  for further information.

:'gems':

  This source-code repository contains Genode applications that use
  both native Genode interfaces as well as features of other high-level
  repositories, in particular shared libraries provided by 'libports'.