glapi/gen: Add code generation script for _mesa_create_exec_table().

This script generates the file api_exec.c, which contains just the
function _mesa_create_exec_table(), based on the XML files in
src/mapi/glapi/gen.

The following XML attributes, in particular, are used:
- "es1" indicates functions that should be available in ES1 contexts.
- "es2" indicates functions that should be available in ES2/ES3
  contexts.
- "exec" indicates which Mesa function should be dispatched to.  E.g.
  if the GL function is glFoo(), then:
  - exec="mesa" (the default) dispatches to _mesa_Foo().
  - exec="check" dispatches to _check_Foo().
  - exec="es" dispatches to _es_Foo().
  - exec="loopback" dispatches to loopback_Foo().
  - exec="skip" or exec="dynamic" causes this function to be skipped;
    either it is not yet supported ("skip"), or its dispatch table
    entry will be dynamically populated based on GL state ("dynamic").
- "desktop" indicates functions that should be available in desktop GL
  (non-ES) contexts.
- "deprecated" indicates functions that should not be available in
  core contexts.
- "mesa_name" indicates functions whose implementation in Mesa has a
  different suffix than the corresponding GL function name.

The generated code looks roughly like this (showing just a single
statement in each block for brevity):

    struct _glapi_table *
    _mesa_create_exec_table(struct gl_context *ctx)
    {
       struct _glapi_table *exec;

       exec = _mesa_alloc_dispatch_table(_gloffset_COUNT);
       if (exec == NULL)
          return NULL;

       if (_mesa_is_desktop_gl(ctx)) {
          SET_ActiveProgramEXT(exec, _mesa_ActiveProgramEXT);
          /* other functions not shown */
       }
       if (_mesa_is_desktop_gl(ctx) || _mesa_is_gles3(ctx)) {
          SET_BeginQueryARB(exec, _mesa_BeginQueryARB);
          /* other functions not shown */
       }
       if (_mesa_is_desktop_gl(ctx) || ctx->API == API_OPENGLES) {
          SET_GetPointerv(exec, _mesa_GetPointerv);
          /* other functions not shown */
       }
       if (_mesa_is_desktop_gl(ctx) || ctx->API == API_OPENGLES || ctx->API == API_OPENGLES2) {
          SET_ActiveTextureARB(exec, _mesa_ActiveTextureARB);
          /* other functions not shown */
       }
       if (_mesa_is_desktop_gl(ctx) || ctx->API == API_OPENGLES2) {
          SET_AttachShader(exec, _mesa_AttachShader);
          /* other functions not shown */
       }
       if (ctx->API == API_OPENGL) {
          SET_Accum(exec, _mesa_Accum);
          /* other functions not shown */
       }
       if (ctx->API == API_OPENGL || ctx->API == API_OPENGLES) {
          SET_AlphaFunc(exec, _mesa_AlphaFunc);
          /* other functions not shown */
       }
       if (ctx->API == API_OPENGLES) {
          SET_AlphaFuncxOES(exec, _es_AlphaFuncx);
          /* other functions not shown */
       }

       return exec;
    }

Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>

diff --git a/src/mapi/glapi/gen/gl_genexec.py b/src/mapi/glapi/gen/gl_genexec.py
new file mode 100644 (file)
index 0000000..adfa595
--- /dev/null
+++ b/src/mapi/glapi/gen/gl_genexec.py
@@ -0,0 +1,222 @@
+#!/usr/bin/env python
+
+# Copyright (C) 2012 Intel Corporation
+#
+# Permission is hereby granted, free of charge, to any person obtaining a
+# copy of this software and associated documentation files (the "Software"),
+# to deal in the Software without restriction, including without limitation
+# the rights to use, copy, modify, merge, publish, distribute, sublicense,
+# and/or sell copies of the Software, and to permit persons to whom the
+# Software is furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice (including the next
+# paragraph) shall be included in all copies or substantial portions of the
+# Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+# IN THE SOFTWARE.
+
+# This script generates the file api_exec.c, which contains
+# _mesa_create_exec_table().  It is responsible for populating all
+# entries in the "exec" dispatch table that aren't dynamic.
+
+import collections
+import license
+import gl_XML
+import sys, getopt
+
+
+exec_flavor_map = {
+    'check': '_check_',
+    'dynamic': None,
+    'es': '_es_',
+    'loopback': 'loopback_',
+    'mesa': '_mesa_',
+    'skip': None,
+    }
+
+
+header = """/**
+ * \\file api_exec.c
+ * Initialize dispatch table.
+ */
+
+
+#include "main/mfeatures.h"
+#include "main/accum.h"
+#include "main/api_loopback.h"
+#include "main/api_exec.h"
+#include "main/arbprogram.h"
+#include "main/atifragshader.h"
+#include "main/attrib.h"
+#include "main/blend.h"
+#include "main/bufferobj.h"
+#include "main/arrayobj.h"
+#include "main/buffers.h"
+#include "main/clear.h"
+#include "main/clip.h"
+#include "main/colortab.h"
+#include "main/condrender.h"
+#include "main/context.h"
+#include "main/convolve.h"
+#include "main/depth.h"
+#include "main/dlist.h"
+#include "main/drawpix.h"
+#include "main/drawtex.h"
+#include "main/rastpos.h"
+#include "main/enable.h"
+#include "main/errors.h"
+#include "main/es1_conversion.h"
+#include "main/eval.h"
+#include "main/get.h"
+#include "main/feedback.h"
+#include "main/fog.h"
+#include "main/fbobject.h"
+#include "main/framebuffer.h"
+#include "main/hint.h"
+#include "main/histogram.h"
+#include "main/imports.h"
+#include "main/light.h"
+#include "main/lines.h"
+#include "main/matrix.h"
+#include "main/multisample.h"
+#include "main/pixel.h"
+#include "main/pixelstore.h"
+#include "main/points.h"
+#include "main/polygon.h"
+#include "main/querymatrix.h"
+#include "main/queryobj.h"
+#include "main/readpix.h"
+#include "main/samplerobj.h"
+#include "main/scissor.h"
+#include "main/stencil.h"
+#include "main/texenv.h"
+#include "main/texgetimage.h"
+#include "main/teximage.h"
+#include "main/texgen.h"
+#include "main/texobj.h"
+#include "main/texparam.h"
+#include "main/texstate.h"
+#include "main/texstorage.h"
+#include "main/texturebarrier.h"
+#include "main/transformfeedback.h"
+#include "main/mtypes.h"
+#include "main/varray.h"
+#include "main/viewport.h"
+#include "main/shaderapi.h"
+#include "main/uniforms.h"
+#include "main/syncobj.h"
+#include "main/dispatch.h"
+
+
+/**
+ * Initialize a dispatch table with pointers to Mesa's immediate-mode
+ * commands.
+ *
+ * Pointers to glBegin()/glEnd() object commands and a few others
+ * are provided via the GLvertexformat interface.
+ *
+ * \param ctx  GL context to which \c exec belongs.
+ * \param exec dispatch table.
+ */
+struct _glapi_table *
+_mesa_create_exec_table(struct gl_context *ctx)
+{
+   struct _glapi_table *exec;
+
+   exec = _mesa_alloc_dispatch_table(_gloffset_COUNT);
+   if (exec == NULL)
+      return NULL;
+
+"""
+
+
+footer = """
+   return exec;
+}
+"""
+
+
+class PrintCode(gl_XML.gl_print_base):
+
+    def __init__(self):
+        gl_XML.gl_print_base.__init__(self)
+
+        self.name = 'gl_genexec.py'
+        self.license = license.bsd_license_template % (
+            'Copyright (C) 2012 Intel Corporation',
+            'Intel Corporation')
+
+    def printRealHeader(self):
+        print header
+
+    def printRealFooter(self):
+        print footer
+
+    def printBody(self, api):
+        # Collect SET_* calls by the condition under which they should
+        # be called.
+        settings_by_condition = collections.defaultdict(lambda: [])
+        for f in api.functionIterateAll():
+            if f.exec_flavor not in exec_flavor_map:
+                raise Exception(
+                    'Unrecognized exec flavor {0!r}'.format(f.exec_flavor))
+            condition_parts = []
+            if f.desktop:
+                if f.deprecated:
+                    condition_parts.append('ctx->API == API_OPENGL')
+                else:
+                    condition_parts.append('_mesa_is_desktop_gl(ctx)')
+            if 'es1' in f.api_map:
+                condition_parts.append('ctx->API == API_OPENGLES')
+            if 'es2' in f.api_map:
+                if f.api_map['es2'] == 3:
+                    condition_parts.append('_mesa_is_gles3(ctx)')
+                else:
+                    condition_parts.append('ctx->API == API_OPENGLES2')
+            if not condition_parts:
+                # This function does not exist in any API.
+                continue
+            condition = ' || '.join(condition_parts)
+            prefix = exec_flavor_map[f.exec_flavor]
+            if prefix is None:
+                # This function is not implemented, or is dispatched
+                # dynamically.
+                continue
+            settings_by_condition[condition].append(
+                'SET_{0}(exec, {1}{2});'.format(f.name, prefix, f.mesa_name))
+        # Print out an if statement for each unique condition, with
+        # the SET_* calls nested inside it.
+        for condition in sorted(settings_by_condition.keys()):
+            print '   if ({0}) {{'.format(condition)
+            for setting in sorted(settings_by_condition[condition]):
+                print '      {0}'.format(setting)
+            print '   }'
+
+
+def show_usage():
+    print "Usage: %s [-f input_file_name]" % sys.argv[0]
+    sys.exit(1)
+
+
+if __name__ == '__main__':
+    file_name = "gl_and_es_API.xml"
+
+    try:
+        (args, trail) = getopt.getopt(sys.argv[1:], "m:f:")
+    except Exception,e:
+        show_usage()
+
+    for (arg,val) in args:
+        if arg == "-f":
+            file_name = val
+
+    printer = PrintCode()
+
+    api = gl_XML.parse_GL_API(file_name)
+    printer.Print(api)