EGL: Implement the libglvnd interface for EGL (v3)

The new interface mostly just sits on top of the existing library.

The only change to the existing EGL code is to split the client
extension string into platform extensions and everything else. On
non-glvnd builds, eglQueryString will just concatenate the two strings.

The EGL dispatch stubs are all generated. The script is based on the one
used to generate entrypoints in libglvnd itself.

v2: [Kyle]
 - Rebased against master.
 - Reworked the EGL makefile to use separate libraries
 - Made the EGL code generation scripts work with Python 2 and 3.
 - Change gen_egl_dispatch.py to use argparse for the command line arguments.
 - Assorted formatting and style cleanup in the Python scripts.

v3: [Emil Velikov]
 - Rebase
 - Remove separate glvnd glx/egl configure toggles

Signed-off-by: Emil Velikov <[email protected]>

1 files changed, 250 insertions, 0 deletions

diff --git a/src/egl/generate/gen_egl_dispatch.py b/src/egl/generate/gen_egl_dispatch.py
new file mode 100644
index 00000000000..eeb3f3f9a5a
--- /dev/null
+++ b/src/egl/generate/gen_egl_dispatch.py
@@ -0,0 +1,250 @@
+#!/usr/bin/env python
+
+# (C) Copyright 2016, NVIDIA CORPORATION.
+# All Rights Reserved.
+#
+# 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
+# on the rights to use, copy, modify, merge, publish, distribute, sub
+# license, 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 NON-INFRINGEMENT.  IN NO EVENT SHALL
+# IBM AND/OR ITS SUPPLIERS 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.
+#
+# Authors:
+#    Kyle Brenneman <[email protected]>
+
+"""
+Generates dispatch functions for EGL.
+
+The list of functions and arguments is read from the Khronos's XML files, with
+additional information defined in the module eglFunctionList.
+"""
+
+import argparse
+import collections
+import imp
+import sys
+import textwrap
+
+import genCommon
+
+def main():
+    parser = argparse.ArgumentParser()
+    parser.add_argument("target", choices=("header", "source"),
+            help="Whether to build the source or header file.")
+    parser.add_argument("func_list_file", help="The function list .py file.")
+    parser.add_argument("xml_files", nargs="+", help="The XML files with the EGL function lists.")
+
+    args = parser.parse_args()
+
+    # The function list is a Python module, but it's specified on the command
+    # line.
+    eglFunctionList = imp.load_source("eglFunctionList", args.func_list_file)
+
+    xmlFunctions = genCommon.getFunctions(args.xml_files)
+    xmlByName = dict((f.name, f) for f in xmlFunctions)
+    functions = []
+    for (name, eglFunc) in eglFunctionList.EGL_FUNCTIONS:
+        func = xmlByName[name]
+        eglFunc = fixupEglFunc(func, eglFunc)
+        functions.append((func, eglFunc))
+
+    # Sort the function list by name.
+    functions = sorted(functions, key=lambda f: f[0].name)
+
+    if args.target == "header":
+        text = generateHeader(functions)
+    elif args.target == "source":
+        text = generateSource(functions)
+    sys.stdout.write(text)
+
+def fixupEglFunc(func, eglFunc):
+    result = dict(eglFunc)
+    if result.get("prefix") is None:
+        result["prefix"] = ""
+
+    if result.get("extension") is not None:
+        text = "defined(" + result["extension"] + ")"
+        result["extension"] = text
+
+    if result["method"] in ("none", "custom"):
+        return result
+
+    if result["method"] not in ("display", "device", "current"):
+        raise ValueError("Invalid dispatch method %r for function %r" % (result["method"], func.name))
+
+    if func.hasReturn():
+        if result.get("retval") is None:
+            result["retval"] = getDefaultReturnValue(func.rt)
+
+    return result
+
+def generateHeader(functions):
+    text = textwrap.dedent(r"""
+    #ifndef G_EGLDISPATCH_STUBS_H
+    #define G_EGLDISPATCH_STUBS_H
+
+    #ifdef __cplusplus
+    extern "C" {
+    #endif
+
+    #include <EGL/egl.h>
+    #include <EGL/eglext.h>
+    #include "glvnd/libeglabi.h"
+
+    """.lstrip("\n"))
+
+    text += "enum {\n"
+    for (func, eglFunc) in functions:
+        text += generateGuardBegin(func, eglFunc)
+        text += "    __EGL_DISPATCH_" + func.name + ",\n"
+        text += generateGuardEnd(func, eglFunc)
+    text += "    __EGL_DISPATCH_COUNT\n"
+    text += "};\n"
+
+    for (func, eglFunc) in functions:
+        if eglFunc["inheader"]:
+            text += generateGuardBegin(func, eglFunc)
+            text += "{f.rt} EGLAPIENTRY {ex[prefix]}{f.name}({f.decArgs});\n".format(f=func, ex=eglFunc)
+            text += generateGuardEnd(func, eglFunc)
+
+    text += textwrap.dedent(r"""
+    #ifdef __cplusplus
+    }
+    #endif
+    #endif // G_EGLDISPATCH_STUBS_H
+    """)
+    return text
+
+def generateSource(functions):
+    # First, sort the function list by name.
+    text = ""
+    text += '#include "egldispatchstubs.h"\n'
+    text += '#include "g_egldispatchstubs.h"\n'
+    text += "\n"
+
+    for (func, eglFunc) in functions:
+        if eglFunc["method"] not in ("custom", "none"):
+            text += generateGuardBegin(func, eglFunc)
+            text += generateDispatchFunc(func, eglFunc)
+            text += generateGuardEnd(func, eglFunc)
+
+    text += "\n"
+    text += "const char * const __EGL_DISPATCH_FUNC_NAMES[__EGL_DISPATCH_COUNT + 1] = {\n"
+    for (func, eglFunc) in functions:
+        text += generateGuardBegin(func, eglFunc)
+        text += '    "' + func.name + '",\n'
+        text += generateGuardEnd(func, eglFunc)
+    text += "    NULL\n"
+    text += "};\n"
+
+    text += "const __eglMustCastToProperFunctionPointerType __EGL_DISPATCH_FUNCS[__EGL_DISPATCH_COUNT + 1] = {\n"
+    for (func, eglFunc) in functions:
+        text += generateGuardBegin(func, eglFunc)
+        if eglFunc["method"] != "none":
+            text += "    (__eglMustCastToProperFunctionPointerType) " + eglFunc.get("prefix", "") + func.name + ",\n"
+        else:
+            text += "    NULL, // " + func.name + "\n"
+        text += generateGuardEnd(func, eglFunc)
+    text += "    NULL\n"
+    text += "};\n"
+
+    return text
+
+def generateGuardBegin(func, eglFunc):
+    ext = eglFunc.get("extension")
+    if ext is not None:
+        return "#if " + ext + "\n"
+    else:
+        return ""
+
+def generateGuardEnd(func, eglFunc):
+    if eglFunc.get("extension") is not None:
+        return "#endif\n"
+    else:
+        return ""
+
+def generateDispatchFunc(func, eglFunc):
+    text = ""
+
+    if eglFunc.get("static"):
+        text += "static "
+    elif eglFunc.get("public"):
+        text += "PUBLIC "
+    text += textwrap.dedent(
+    r"""
+    {f.rt} EGLAPIENTRY {ef[prefix]}{f.name}({f.decArgs})
+    {{
+        typedef {f.rt} EGLAPIENTRY (* _pfn_{f.name})({f.decArgs});
+    """).lstrip("\n").format(f=func, ef=eglFunc)
+
+    if func.hasReturn():
+        text += "    {f.rt} _ret = {ef[retval]};\n".format(f=func, ef=eglFunc)
+
+    text += "    _pfn_{f.name} _ptr_{f.name} = (_pfn_{f.name}) ".format(f=func)
+    if eglFunc["method"] == "current":
+        text += "__eglDispatchFetchByCurrent(__EGL_DISPATCH_{f.name});\n".format(f=func)
+
+    elif eglFunc["method"] in ("display", "device"):
+        if eglFunc["method"] == "display":
+            lookupFunc = "__eglDispatchFetchByDisplay"
+            lookupType = "EGLDisplay"
+        else:
+            assert eglFunc["method"] == "device"
+            lookupFunc = "__eglDispatchFetchByDevice"
+            lookupType = "EGLDeviceEXT"
+
+        lookupArg = None
+        for arg in func.args:
+            if arg.type == lookupType:
+                lookupArg = arg.name
+                break
+        if lookupArg is None:
+            raise ValueError("Can't find %s argument for function %s" % (lookupType, func.name,))
+
+        text += "{lookupFunc}({lookupArg}, __EGL_DISPATCH_{f.name});\n".format(
+                f=func, lookupFunc=lookupFunc, lookupArg=lookupArg)
+    else:
+        raise ValueError("Unknown dispatch method: %r" % (eglFunc["method"],))
+
+    text += "    if(_ptr_{f.name} != NULL) {{\n".format(f=func)
+    text += "        "
+    if func.hasReturn():
+        text += "_ret = "
+    text += "_ptr_{f.name}({f.callArgs});\n".format(f=func)
+    text += "    }\n"
+
+    if func.hasReturn():
+        text += "    return _ret;\n"
+    text += "}\n"
+    return text
+
+def getDefaultReturnValue(typename):
+    if typename.endswith("*"):
+        return "NULL"
+    elif typename == "EGLDisplay":
+        return "EGL_NO_DISPLAY"
+    elif typename == "EGLContext":
+        return "EGL_NO_CONTEXT"
+    elif typename == "EGLSurface":
+        return "EGL_NO_SURFACE"
+    elif typename == "EGLBoolean":
+        return "EGL_FALSE";
+
+    return "0"
+
+if __name__ == "__main__":
+    main()
+