opengl/libs/EGL/getProcAddress.cpp

/*
 ** Copyright 2009, The Android Open Source Project
 **
 ** Licensed under the Apache License, Version 2.0 (the "License");
 ** you may not use this file except in compliance with the License.
 ** You may obtain a copy of the License at
 **
 **     http://www.apache.org/licenses/LICENSE-2.0
 **
 ** Unless required by applicable law or agreed to in writing, software
 ** distributed under the License is distributed on an "AS IS" BASIS,
 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 ** See the License for the specific language governing permissions and
 ** limitations under the License.
 */

#include <ctype.h>
#include <stdlib.h>
#include <errno.h>

#include <cutils/log.h>

#include "egldefs.h"

// ----------------------------------------------------------------------------
namespace android {
// ----------------------------------------------------------------------------

#undef API_ENTRY
#undef CALL_GL_EXTENSION_API
#undef GL_EXTENSION
#undef GL_EXTENSION_NAME
#undef GL_EXTENSION_ARRAY
#undef GL_EXTENSION_LIST
#undef GET_TLS

#if defined(__arm__)

    #define GET_TLS(reg) "mrc p15, 0, " #reg ", c13, c0, 3 \n"

    #define API_ENTRY(_api) __attribute__((naked)) _api

    #define CALL_GL_EXTENSION_API(_api)                         \
         asm volatile(                                          \
            GET_TLS(r12)                                        \
            "ldr   r12, [r12, %[tls]] \n"                       \
            "cmp   r12, #0            \n"                       \
            "ldrne r12, [r12, %[api]] \n"                       \
            "cmpne r12, #0            \n"                       \
            "bxne  r12                \n"                       \
            "bx    lr                 \n"                       \
            :                                                   \
            : [tls] "J"(TLS_SLOT_OPENGL_API*4),                 \
              [api] "J"(__builtin_offsetof(gl_hooks_t,          \
                                      ext.extensions[_api]))    \
            :                                                   \
            );

#elif defined(__mips__)

        #define API_ENTRY(_api) __attribute__((noinline)) _api

        #define CALL_GL_EXTENSION_API(_api, ...)                    \
            register unsigned int _t0 asm("t0");                    \
            register unsigned int _fn asm("t1");                    \
            register unsigned int _tls asm("v1");                   \
            asm volatile(                                           \
                ".set  push\n\t"                                    \
                ".set  noreorder\n\t"                               \
                ".set  mips32r2\n\t"                                \
                "rdhwr %[tls], $29\n\t"                             \
                "lw    %[t0], %[OPENGL_API](%[tls])\n\t"            \
                "beqz  %[t0], 1f\n\t"                               \
                " move %[fn], $ra\n\t"                              \
                "lw    %[fn], %[API](%[t0])\n\t"                    \
                "movz  %[fn], $ra, %[fn]\n\t"                       \
                "1:\n\t"                                            \
                "j     %[fn]\n\t"                                   \
                " nop\n\t"                                          \
                ".set  pop\n\t"                                     \
                : [fn] "=c"(_fn),                                   \
                  [tls] "=&r"(_tls),                                \
                  [t0] "=&r"(_t0)                                   \
                : [OPENGL_API] "I"(TLS_SLOT_OPENGL_API*4),          \
                  [API] "I"(__builtin_offsetof(gl_hooks_t,          \
                                          ext.extensions[_api]))    \
                :                                                   \
            );
#endif

#if defined(CALL_GL_EXTENSION_API)
    #define GL_EXTENSION_NAME(_n)   __glExtFwd##_n

    #define GL_EXTENSION(_n)                         \
        void API_ENTRY(GL_EXTENSION_NAME(_n))() {    \
            CALL_GL_EXTENSION_API(_n);               \
        }
#else
        #define GL_EXTENSION_NAME(_n) NULL

        #define GL_EXTENSION(_n)

        #warning "eglGetProcAddress() partially supported"
#endif


#define GL_EXTENSION_LIST(name) \
    name(0)   name(1)   name(2)   name(3)   name(4)   name(5)   name(6)   name(7)  \
    name(8)   name(9)   name(10)  name(11)  name(12)  name(13)  name(14)  name(15) \
    name(16)  name(17)  name(18)  name(19)  name(20)  name(21)  name(22)  name(23) \
    name(24)  name(25)  name(26)  name(27)  name(28)  name(29)  name(30)  name(31) \
    name(32)  name(33)  name(34)  name(35)  name(36)  name(37)  name(38)  name(39) \
    name(40)  name(41)  name(42)  name(43)  name(44)  name(45)  name(46)  name(47) \
    name(48)  name(49)  name(50)  name(51)  name(52)  name(53)  name(54)  name(55) \
    name(56)  name(57)  name(58)  name(59)  name(60)  name(61)  name(62)  name(63) \
    name(64)  name(65)  name(66)  name(67)  name(68)  name(69)  name(70)  name(71) \
    name(72)  name(73)  name(74)  name(75)  name(76)  name(77)  name(78)  name(79) \
    name(80)  name(81)  name(82)  name(83)  name(84)  name(85)  name(86)  name(87) \
    name(88)  name(89)  name(90)  name(91)  name(92)  name(93)  name(94)  name(95) \
    name(96)  name(97)  name(98)  name(99)  \
    name(100) name(101) name(102) name(103) name(104) name(105) name(106) name(107) \
    name(108) name(109) name(110) name(111) name(112) name(113) name(114) name(115) \
    name(116) name(117) name(118) name(119) name(120) name(121) name(122) name(123) \
    name(124) name(125) name(126) name(127) name(128) name(129) name(130) name(131) \
    name(132) name(133) name(134) name(135) name(136) name(137) name(138) name(139) \
    name(140) name(141) name(142) name(143) name(144) name(145) name(146) name(147) \
    name(148) name(149) name(150) name(151) name(152) name(153) name(154) name(155) \
    name(156) name(157) name(158) name(159) name(160) name(161) name(162) name(163) \
    name(164) name(165) name(166) name(167) name(168) name(169) name(170) name(171) \
    name(172) name(173) name(174) name(175) name(176) name(177) name(178) name(179) \
    name(180) name(181) name(182) name(183) name(184) name(185) name(186) name(187) \
    name(188) name(189) name(190) name(191) name(192) name(193) name(194) name(195) \
    name(196) name(197) name(198) name(199) \
    name(200) name(201) name(202) name(203) name(204) name(205) name(206) name(207) \
    name(208) name(209) name(210) name(211) name(212) name(213) name(214) name(215) \
    name(216) name(217) name(218) name(219) name(220) name(221) name(222) name(223) \
    name(224) name(225) name(226) name(227) name(228) name(229) name(230) name(231) \
    name(232) name(233) name(234) name(235) name(236) name(237) name(238) name(239) \
    name(240) name(241) name(242) name(243) name(244) name(245) name(246) name(247) \
    name(248) name(249) name(250) name(251) name(252) name(253) name(254) name(255)


GL_EXTENSION_LIST( GL_EXTENSION )

#define GL_EXTENSION_ARRAY(_n)  GL_EXTENSION_NAME(_n),

extern const __eglMustCastToProperFunctionPointerType gExtensionForwarders[MAX_NUMBER_OF_GL_EXTENSIONS] = {
        GL_EXTENSION_LIST( GL_EXTENSION_ARRAY )
 };

#undef GET_TLS
#undef GL_EXTENSION_LIST
#undef GL_EXTENSION_ARRAY
#undef GL_EXTENSION_NAME
#undef GL_EXTENSION
#undef API_ENTRY
#undef CALL_GL_EXTENSION_API

// ----------------------------------------------------------------------------
}; // namespace android
// ----------------------------------------------------------------------------