Fixup APIENTRY macro on Apple

The version of glut.h that ships on Mac OSX undefines the APIENTRY
macro.  APIENTRY is used on Windows builds to specify that GL
functions use the __stdcall calling convention, so it needs to be
defined to be the empty string on Mac OSX.  Previously this hasn't
been a problem because all of the GL function prototypes and typedefs
are finished by the time glut.h is included.  However, when we switch
to using piglit-dispatch instead of GLEW, there will be at least one
compilation unit (piglit-dispatch.c) which needs to use the APIENTRY
macro after including glut.h.

This patch works around the problem by redefining APIENTRY to the
correct value (which is the empty string) after including glut.h on
Apple builds.
piglit-dispatch: Introduce OpenGL API spec files.

This is the first in a series of patches that replaces GLEW with a new
mechanism called "piglit-dispatch".

This patch introduces files which describe the OpenGL API in
machine-readable form.  These files are duplicates of those found at
http://www.opengl.org/registry/.

The exact URLs of the files are as follows:

http://www.opengl.org/registry/api/gl.spec
http://www.opengl.org/registry/api/gl.tm
http://www.opengl.org/registry/api/enumext.spec

Later patches in the series will transform these spec files to C code.

Reviewed-by: Chad Versace <chad.versace@linux.intel.com>
piglit-dispatch: Corrections to OpenGL API spec files.

This patch corrects a few minor errors in the OpenGL API spec files
from http://www.opengl.org/registry/:

- ALL_ATTRIB_BITS was incorrectly defined as 0xFFFFFFFF.  The correct
  value is 0x000FFFFF, since ALL_ATTRIB_BITS is not meant to apply to
  MULTISAMPLE_BIT (see extension specs 3DFX_multisample,
  ARB_multisample, EXT_multisample, and SGIS_multisample).

- IsProgramARB and IsProgramNV were incorrectly marked as aliases of
  IsProgram.  This is not the case, since IsProgram is used for GLSL
  programs, and IsProgramARB/IsProgramNV are used for assembly
  programs.

- GenVertexArraysAPPLE was incorrectly marked as an alias for
  "GenVertexArray".  There is no such function--the correct function
  is "GenVertexArrays".

- TransformFeedbackVaryingsNV was incorrectly marked as an alias for
  TransformFeedbackVaryings.  This is incorrect--the two functions
  interpret their arguments differently.  Similarly,
  GetTransformFeedbackVaryingNV was incorrectly marked as an alias for
  GetTransformFeedbackVarying.

- StencilFuncSeparateATI was incorrectly marked as an alias for
  StencilFuncSeparate.  This is incorrect--the two functions interpret
  their arguments differently.

- NV functions dealing with vertex attributes
  (GetVertexAttrib{d,f,i}vNV, VertexAttrib{1,2,3,4}{d,f,s}{,v}NV, and
  VertexAttrib4ub{,v}NV) were incorrectly marked as an alias for the
  corresponding core functions.  This is incorrect--NV extensions
  handle vertex attribute numbering differently.

The reason these errors were not caught by the maintainers of
opengl.org is likely because they don't affect the contents of the
glext.h header file.

Acked-by: Chad Versace <chad.versace@linux.intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
piglit-dispatch: Additions to OpenGL API spec files.

This patch adds enums for the following extensions to the OpenGL API
spec files:

- OES_compressed_paletted_texture: This extension defines 10 enums,
  which are required to compile the test
  "spec/OES_compressed_paletted_texture/invalid formats".  These enums
  were already present in the OpenGL API spec files, but they were
  commented out (since they are part of GLES).

- ATI_texture_compression_3dc: These enums are required to compile the
  test "spec/ARB_texture_compression/unknown formats".

- NVX_gpu_memory_info: These enums are required to compile the file
  "tests/util/piglit-util-enum.c".

Reviewed-by: Chad Versace <chad.versace@linux.intel.com>
piglit-dispatch: Code generation scripts.

This patch contains the code generation scripts that convert the files
gl.spec, gl.tm, and enumext.spec into C code, as well as the CMake
directives to run the scripts.

Code generation occurs in two phases: first the script
glapi/parse_glspec.py converts the .spec and .tm files into an
intermediate JSON format, which is stored in glapi/glapi.json.  Then,
the script tests/util/gen_dispatch.py converts the JSON file into two
files, tests/util/generated_dispatch.c and
tests/util/generated_dispatch.h.

There are two motivations for breaking code generation into two phases:
(1) there are other code generation tasks we may add in the future
(e.g. generating the tests/util/piglit-util-enum.c file), and it would
be nice not to have to rewrite any parsing code when we do so.  (2) if
the GL consortium ever decides to change the format of gl.spec, gl.tm,
and enumext.spec, then we only have to change parse_glspec.py.

These code generation scripts can be run by invoking "make
piglit_dispatch_gen" from the toplevel source directory.

v2: Add clarifying comments, remove a bogus "print" statement, and
raise an exception if an unrecognized multiplicity is encountered.
Also, handle "reference" multiplicity.

v3: Add APIENTRY to stub functions.  Rename "near" and "far" to avoid
problems on MSVC.  Get rid of "__" in function names.  Rename
initialize_dispatch_pointers => reset_dispatch_pointers.
piglit-dispatch: Add generated files.

This patch adds the files glapi/glapi.json,
tests/util/generated_dispatch.c, and tests/util/generated_dispatch.h,
which were generated using the command "make piglit_dispatch_gen".
piglit-dispatch: Remaining infrastructure.

Previous patches introduced code generation for the auto-generated
portions of the piglit-dispatch mechanism.  This patch supplies the
remaining hand-written code, which includes:

- Code to initialize piglit-dispatch.

- The actions to be taken when looking up a function, when function
  lookup fails, or when a function is unsupported.

- Code to determine whether piglit-dispatch has been initialized,
  which GL version is supported, and whether a given extension is
  supported.

- Code to look up a function using a name supplied at run-time.

- Definitions of basic GL types.

v2: Make "inline" work in MSVC.  Fix type of intermediate function
pointers.  Only try to include "glxew.h" on Linux.  Fix MSVC
definition of int8_t.  Add #include "piglit-dispatch.h" to
piglit-dispatch.c for clarity.  Get rid of "__" in function names.
Only call reset_dispatch_pointers() if necessary.  Use "\param" in
comments.
piglit-dispatch: Switch to using piglit-dispatch instead of GLEW.

Previous patches set up the piglit-dispatch infrastructure but did not
use it.  This patch enables piglit-dispatch and uses it instead of
GLEW.

No piglit regressions on Intel SandyBridge (Linux) or Mac OSX.

v2: Remove redundant includes of GL headers.
Windows experiment: disable default_get_proc_address.
Windows experiment: define APIENTRY/GLAPIENTRY properly on Windows.
piglit-dispatch: Remove GLEW.

This patch removes the files glew.c and glew.h, which are no longer
used.  The "piglit-dispatch" mechanism is used instead.

Reviewed-by: Chad Versace <chad.versace@linux.intel.com>
Remove GLEW workarounds.

This patch removes workarounds that were in place to compensate for
bugs in GLEW.

Reviewed-by: Chad Versace <chad.versace@linux.intel.com>
Windows experiment: only do the bool workaround if not c++
glean: use piglit_get_proc_address().

Previously glean got the address of GL functions by directly calling
an OS-specific function (e.g. glXGetProcAddressARB(), dlsym(), or
wglGetProcAddress()).  This patch changes it to use
piglit_get_proc_address(), which uses piglit-dispatch.  This will help
pave the way for adapting glean to test using GLES and
forward-compatible contexts.

Reviewed-by: Chad Versace <chad.versace@linux.intel.com>

v2: Changed the return type of glean's getProcAddress to "void
(APIENTRY *)()" so that no type casting is necessary on Windows.
Windows experiments
Windows debug
Windows debug
Windows debug
Windows debug info
Windows experiment: always go through wglGetProcAddress