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 <errno.h>
#include <log/log.h>
#include <stdlib.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

// clang-format off
#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"                       \
            "addne r12, %[api]        \n"                       \
            "ldrne r12, [r12, %[ext]] \n"                       \
            "cmpne r12, #0            \n"                       \
            "bxne  r12                \n"                       \
            "bx    lr                 \n"                       \
            :                                                   \
            : [tls] "J"(TLS_SLOT_OPENGL_API*4),                 \
              [ext] "J"(__builtin_offsetof(gl_hooks_t,          \
                                      ext.extensions[0])),      \
              [api] "I"(_api*sizeof(void*))                     \
            : "r12"                                             \
            );

#elif defined(__aarch64__)

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

    #define CALL_GL_EXTENSION_API(_api)                             \
        asm volatile(                                               \
            "mrs x16, tpidr_el0\n"                                  \
            "ldr x16, [x16, %[tls]]\n"                              \
            "cbz x16, 1f\n"                                         \
            "ldr x16, [x16, %[api]]\n"                              \
            "cbz x16, 1f\n"                                         \
            "br  x16\n"                                             \
            "1:\n"                                                  \
            :                                                       \
            : [tls] "i" (TLS_SLOT_OPENGL_API * sizeof(void*)),      \
              [api] "i" (__builtin_offsetof(gl_hooks_t,             \
                                        ext.extensions[_api]))      \
            : "x16"                                                 \
        );

#elif defined(__i386__)

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

    #define CALL_GL_EXTENSION_API(_api)                         \
         __asm__ volatile(                                      \
            "mov %%gs:0, %%eax\n"                               \
            "mov %P[tls](%%eax), %%eax\n"                       \
            "test %%eax, %%eax\n"                               \
            "cmovne %P[api](%%eax), %%eax\n"                    \
            "test %%eax, %%eax\n"                               \
            "je 1f\n"                                           \
            "jmp *%%eax\n"                                      \
            "1: ret\n"                                          \
            :                                                   \
            : [tls] "i" (TLS_SLOT_OPENGL_API*sizeof(void*)),    \
              [api] "i" (__builtin_offsetof(gl_hooks_t,         \
                                      ext.extensions[_api]))    \
            : "eax", "cc"                                       \
            );

#elif defined(__x86_64__)

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

    #define CALL_GL_EXTENSION_API(_api)                         \
         __asm__ volatile(                                      \
            "mov %%fs:0, %%rax\n"                               \
            "mov %P[tls](%%rax), %%rax\n"                       \
            "test %%rax, %%rax\n"                               \
            "cmovne %P[api](%%rax), %%rax\n"                    \
            "test %%rax, %%rax\n"                               \
            "je 1f\n"                                           \
            "jmp *%%rax\n"                                      \
            "1: ret\n"                                          \
            :                                                   \
            : [tls] "i" (TLS_SLOT_OPENGL_API*sizeof(void*)),    \
              [api] "i" (__builtin_offsetof(gl_hooks_t,         \
                                      ext.extensions[_api]))    \
            : "rax", "cc"                                       \
            );

#elif defined(__riscv)
    #define API_ENTRY(_api) __attribute__((noinline)) _api

    #define CALL_GL_EXTENSION_API(_api)                             \
        asm volatile(                                               \
            "mv t0, tp\n"                                           \
            "li t1, %[tls]\n"                                       \
            "add t0, t0, t1\n"                                      \
            "ld t0, 0(t0)\n"                                        \
            "beqz t0, 1f\n"                                         \
            "li t1, %[api]\n"                                       \
            "add t0, t0, t1\n"                                      \
            "ld t0, 0(t0)\n"                                        \
            "jalr x0, t0\n"                                         \
            "1: ret\n"                                              \
            :                                                       \
            : [tls] "i" (TLS_SLOT_OPENGL_API * sizeof(void*)),      \
              [api] "i" (__builtin_offsetof(gl_hooks_t,             \
                                        ext.extensions[_api]))      \
            : "t0", "t1"                                            \
        );

#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),
// clang-format on

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