These have dlsym versions of GLIBC_2.3 and GLIBC_2.2, respectively.

Signed-off-by: Adam Jackson <ajax@redhat.com>

If a parent directory of the libepoxy source dir contains a space,
'cd' in line 10 fails.

Client extensions are always available, and are only listed in
eglQueryString(dpy=NULL). Without this we can't call anything from e.g.
EXT_platform_base.

Signed-off-by: Adam Jackson <ajax@redhat.com>

Binding an API does not change the type of the current context. Even if
it did, EGL 1.5 treats EGL_OPENGL_API and EGL_OPENGLES_API as identical
for this purpose.  If you want to know properties of the current
context, query it.

Signed-off-by: Adam Jackson <ajax@redhat.com>

Most of the changes that happened after commit 8bbc0d4 broke epoxy
pretty much irreparably because of the CMake build and the attempt at
making libepoxy a static library that can be copy-pasted into another
project without generating files.

Since all the commits are entangled, and are full of unrelated changes,
we cannot simply do a localized set of reverts; instead, we need to hit
the reset button.

From this point forward, we're going to improve libepoxy's build while
attempting to keep the existing build system working. This may mean
reinstating the CMake build system at a later date.

 ...so that the generated code are buildable by pre-2013 Visual Studio.

 The main thing that this does is that we avoid named initializers, but
 instead initialize the structs in old-school C89 way.

 The generated code may not look that robust, but since this is generated
 code, I think this is not that much an issue; when the Khronos registry gets
 updated, all that is needed is that the code gets re-generated, and we have the
 items in the right order.

Signed-off-by: Emmanuele Bassi <ebassi@gnome.org>

The code used to check this symbol, but commit 689abf4 replaced it with
GLX_H, presumably to work better with either Mesa or Khronos headers.
But nVidia's header use the older include guard. Add it as another
option.

Should fix the headerguards.c compile test when the system glx.h is from
nVidia's binary drivers.

Signed-off-by: Emmanuele Bassi <ebassi@gnome.org>

Some X server not supporting any OpenGL feature, glXQueryExtensionsString
will return NULL and causes the function to fail.

Thanks to Emmanuel Stapf (manus@eiffel.com) for the original patch.

This was verified running an application on macOS while the X server was
running on Windows Xming 7.5.0.10

Signed-off-by: Emmanuele Bassi <ebassi@gnome.org>

Signed-off-by: Emmanuele Bassi <ebassi@gnome.org>

See sysdeps/unix/sysv/linux/arm/libdl.abilist in glibc

Signed-off-by: Emmanuele Bassi <ebassi@gnome.org>

The rest of the library is C89-only, so we should keep it that way.

Closes anholt#90

Closes PR: anholt#83

Closes PR: anholt#88

Completes commit 83cfa6a.

Closes PR: anholt#75

Conflicts:
        test/dlwrap.c

The gen_dispatch.py script relies on the source and include directories
to exist before dumping the files in there, split by type, in order to
sustain the split of the headers existing in a separate root from the
source files. This causes a spooky-action-at-a-distance scenario where
headers are generated by rules inside the source directory but influence
the contents of a separate directory — and require a separate set of
rules to install those headers.

Different build systems would require either splitting the generation in
to two separate passes (which is more expensive and time consuming), or
generate the header and source files in the same directory, and just
tweak the inclusion paths accordingly.

Since we want to maintain this fiction for the autotools build, but
ignore it for different build systems, let's add a separate set of
arguments for gen_dispatch.py that make the rules inside Makefile.am
work appropriately.

Meson is a Python-based build system that generates build rules of
Ninja, Visual Studio, and XCode. It's designed to be fast, and have a
small, non-Turing complete language to describe the build process,
tests, and dependencies. It's simpler than CMake, and faster than
autotools.

As a direct comparison in terms of speed, three build and check runs for
libepoxy from a clean Git repository clone yield these results on my
Kabylake Core i7 7500U (nproc=4):

- Autotools (make)
Run #1 (cold)   real: 22.384s, user: 20.011s, sys: 3.689s
Run anholt#2 (warm)   real: 22.429s, user: 20.220s, sys: 3.708s
Run anholt#3 (warm)   real: 22.068s, user: 19.743s, sys: 3.594s

- Meson (ninja)
Run #1 (cold)   real: 5.932s, user:  9.371s, sys: 1.625s
Run anholt#2 (warm)   real: 6.273s, user: 10.066,  sys: 1.740s
Run anholt#3 (warm)   real: 5.796s, user:  9.233s, sys: 1.607s

Which means that Meson and ninja are approximately 4x faster than
autotools.

In terms of simplicity, the autotools build takes six files and a total
of 645 lines; Meson requires 3 files, and 361 lines to achieve the same
result. Additionally, Meson automatically builds in a separate build
directory and does not leave files inside the source directory; and Meson
does not use libtool.

Since Meson is quite new and still actively developed, we're going to
leave the autotools build in place for a while, with the intention of
switching to Meson in the future.

This maintains the compatibility between the autotools-based build and
the Meson one, mirroring commit 037ac7f.

Meson adds `-Wall` for us with `warning_level=1`.

There's no need to use a leading '/' for the constant chunk, and we
should use the same style consistently.

it seems like this was forgotten,
because glBindFramebufferEXT is already there
for the same reason

Signed-off-by: Emmanuele Bassi <ebassi@gnome.org>

It's possible to tell Meson to build a static library, instead of a
shared one, using a command line option.

We already know the Microsoft Visual C compiler does not support
`-Bsymbolic`.

Certain X server do not have GLX enabled or supported, such as x2go. We
can handle this case gracefully inside libepoxy.

Signed-off-by: Emmanuele Bassi <ebassi@gnome.org>

X11 support is build by default if x11 libs are found. This can be disabled
by --disable-glx.

A similar (bit too overenthusiastic) pull request was sent long time ago [1]
before we saw cmake trouble. There was a follow up PR in [2] but I cannot test
it so took only very common parts.

[1] anholt#52
[2] anholt#81

Signed-off-by: Andreas Müller <schnitzeltony@googlemail.com>