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Neil Roberts 7bf0fe9df8 Don't dereference an unitialised pointer in _cogl_container_of
The previous implementation was dereferencing the sample pointer in
order to get the offset to subtract from the member pointer. The
resulting value is then only used to get a pointer to the member in
order to calculate the offset so it doesn't actually read from the
memory location and shouldn't cause any problems. However this is
probably technically invalid and could have undefined behaviour. It
looks like clang takes advantage of this undefined behaviour and
doesn't actually offset the pointer. It also generates a warning when
it does this.

This patch splits the _cogl_container_of macro into two
implementations. Previously the macro was always used in the list
iterator macros like this:

SomeType *sample = _cogl_container_of(list_node, sample, link)

Instead of doing that there is now a new macro called
_cogl_list_set_iterator which explicitly assigns to the sample pointer
with an initial value before assigning to it again with the real
offset. This redundant initialisation gets optimised out by compiler.

The second macro is still called _cogl_container_of but instead of
taking a sample pointer it just directly takes the type name. That way
it can use the standard offsetof macro.

https://bugzilla.gnome.org/show_bug.cgi?id=723530

Reviewed-by: Robert Bragg <robert@linux.intel.com>
(cherry picked from commit 1efed1e0a2bce706eb4901979ed4e717bb13e4e2)
2014-02-20 13:38:43 +00:00
build mingw-fetch-dependencies: Add the -L option when using curl 2014-01-20 16:41:13 +00:00
cogl Don't dereference an unitialised pointer in _cogl_container_of 2014-02-20 13:38:43 +00:00
cogl-gles2 consistently name cogl-gles2 pkg-config files 2014-01-09 16:03:13 +00:00
cogl-gst cogl-gst: Fix get_caps implementation when no context is set 2014-01-31 12:42:03 +00:00
cogl-pango remove internal_format and redundant error arguments 2014-01-09 15:49:47 +00:00
cogl-path cogl-path: Fix the exported symbols regular expression 2014-01-22 13:15:28 +00:00
deps build: fix make dist 2013-01-22 17:48:03 +00:00
doc Tweak documentation for the CoglTexture interface 2014-01-20 14:32:39 +00:00
examples cogl-basic-video-player: Allow passing a GStreamer pipeline 2014-01-31 12:42:03 +00:00
po Added uk translation 2014-02-14 20:27:51 +02:00
test-fixtures Add support for RG textures 2014-01-20 14:40:45 +00:00
tests Add support for RG textures 2014-01-20 14:40:45 +00:00
.gitignore Update .gitignore 2013-11-29 14:04:39 +00:00
.vimrc misc: Add a .vimrc file 2011-05-17 15:24:54 +01:00
autogen.sh Add support for automake 1.14 2013-07-03 18:11:53 +01:00
ChangeLog dist: Don't use elaborate script to gen Changelogs 2011-07-20 16:58:46 +01:00
cogl.doap Adds an initial cogl.doap file 2011-05-06 12:12:13 +01:00
config-custom.h configure: Force #undef of 'near' and 'far' on Windows 2011-06-14 12:14:02 +01:00
config.h.win32.in Update config.h.win32.in 2013-03-15 00:26:35 +08:00
configure.ac Post-release version bump to 1.17.3 2014-01-20 16:59:10 +00:00
COPYING Update the COPYING file 2011-09-05 19:02:05 +01:00
Makefile.am Build and install cogl-path as a shared library 2013-12-11 18:49:19 +00:00
NEWS Updates NEWS for the 1.17.2 release 2014-01-20 16:41:13 +00:00
README.in README: misc updates 2013-07-09 22:54:02 +01:00

README for Cogl @COGL_1_VERSION@
===============================================================================

Note: This file is delimited with -- markers so it is possible to split
sections out for other purposes, such as for release notes.

--
DESCRIPTION
-------------------------------------------------------------------------------

Cogl is a small open source library for using 3D graphics hardware for
rendering. The API departs from the flat state machine style of OpenGL and is
designed to make it easy to write orthogonal components that can render without
stepping on each others toes.

As well as aiming for a nice API, we think having a single library as opposed
to an API specification like OpenGL has a few advantages too; like being
able to paper over the inconsistencies/bugs of different OpenGL
implementations in a centralized place, not to mention the myriad of OpenGL
extensions. It also means we are in a better position to provide utility
APIs that help software developers since they only need to be implemented
once and there is no risk of inconsistency between implementations.

Having other backends, besides OpenGL, such as drm, Gallium or D3D are
options we are interested in for the future.

--
REQUIREMENTS
-------------------------------------------------------------------------------

Cogl currently only requires:

  • OpenGL ≥ 1.3 (or 1.2 + multitexturing), or OpenGL ES 2.0 (or 1.1)
  • GLX, AGL, WGL or an EGL implementation

Cogl also has optional dependencies:

  • GLib ≥ @GLIB_REQ_VERSION@
     - for gtype integration
  • GDK-Pixbuf ≥ @GDK_PIXBUF_REQ_VERSION@
     - for image loading
  • Cairo ≥ @CAIRO_REQ_VERSION@
     - for debugging texture atlasing (debug builds only)

The optional Cogl Pango library requires:
  • Cairo ≥ @CAIRO_REQ_VERSION@
  • PangoCairo ≥ @PANGOCAIRO_REQ_VERSION@

The optional Cogl GStreamer library requires:

  • GStreamer 1.0

On X11, Cogl depends on the following extensions

  • XComposite ≥ @XCOMPOSITE_REQ_VERSION@
  • XDamage
  • XExt
  • XFixes ≥ @XFIXES_REQ_VERSION@

For the Wayland backend, Cogl requires:
  • Wayland ≥ @WAYLAND_REQ_VERSION@

When running with OpenGL, Cogl requires at least version 1.3
or 1.2 with the multitexturing extension. However to build Cogl
you will need the latest GL headers which can be obtained from:

  http://www.khronos.org

If you are building the API reference you will also need:

  • GTK-Doc ≥ @GTK_DOC_REQ_VERSION@

If you are building the additional documentation you will also need:

  • xsltproc
  • jw (optional, for generating PDFs)

If you are building the Introspection data you will also need:

  • GObject-Introspection ≥ @GI_REQ_VERSION@

GObject-Introspection is available from:

  git://git.gnome.org/gobject-introspection

If you want support for profiling Cogl you will also need:

  • UProf ≥ @UPROF_REQ_VERSION@

UProf is available from:

  git://github.com/rib/UProf.git

--
DOCUMENTATION
-------------------------------------------------------------------------------

The 1.x stable API is documented here:

  http://developer.gnome.org/cogl/stable/

The 1.x development API is documented here:

  http://developer.gnome.org/cogl/1.@COGL_1_MINOR_VERSION@

The experimental 2.0 API is documented here:

  http://cogl3d.org/cogl2-reference/

--
LICENSE
-------------------------------------------------------------------------------

Most of Cogl is licensed under the terms of the GNU Lesser General Public
License, version 2.1 or (at your option) later. Some files are licensed under
more permissive licenses MIT or BSD style licenses though so please see
individual files for details.

--
BUILDING AND INSTALLATION
-------------------------------------------------------------------------------

Please refer to the INSTALL document.

--
BUGS
-------------------------------------------------------------------------------

Please report bugs here:

  http://bugzilla.gnome.org/enter_bug.cgi?product=cogl

You will need a Bugzilla account.

Please include the following in bug reports:

  • what system you're running Cogl on;
  • which version of Cogl you are using;
  • which version of GLib and OpenGL (or OpenGL ES) you are using;
  • which video card and which drivers you are using, including output of
    glxinfo and xdpyinfo (if applicable);
  • how to reproduce the bug.

If you cannot reproduce the bug with one of the tests that come with
Cogl's source code, it can help a lot to include a small test case
displaying the bad behaviour.

If the bug exposes a crash, the exact text printed out and a stack trace
obtained using gdb are greatly appreciated.

--
CONTRIBUTING
-------------------------------------------------------------------------------

The CODING_STYLE file describes the coding style we use throughout Cogl,
please try your best to conform to this style because the consistency
really helps keep the code maintainable.

We can accept contributions in several ways:
  • Either as patches attached to bugs on bugzilla
      - For this you may be interested in using git-bz.

        See http://git.fishsoup.net/man/git-bz.html for details
  • You can email us patches
      - For this we recommend using git-send-email

  • You can create a remote branch and ask us to pull from that for more
    substantial changes.
      - For this we recommend using github.

Ideally standalone patches should be created using git format-patch since
that makes it easiest to import the patch with a commit message into a
git repository.