Import libepoxy 1.2

1 files changed, 666 insertions, 0 deletions

diff --git a/dist/libepoxy/src/dispatch_common.c b/dist/libepoxy/src/dispatch_common.c
new file mode 100644
index 000000000..9d1787844
--- /dev/null
+++ b/dist/libepoxy/src/dispatch_common.c
@@ -0,0 +1,666 @@
+/*
+ * Copyright © 2013-2014 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.
+ */
+
+/**
+ * @file dispatch_common.c
+ *
+ * Implements common code shared by the generated GL/EGL/GLX dispatch code.
+ *
+ * A collection of some important specs on getting GL function pointers.
+ *
+ * From the linux GL ABI (http://www.opengl.org/registry/ABI/):
+ *
+ *     "3.4. The libraries must export all OpenGL 1.2, GLU 1.3, GLX 1.3, and
+ *           ARB_multitexture entry points statically.
+ *
+ *      3.5. Because non-ARB extensions vary so widely and are constantly
+ *           increasing in number, it's infeasible to require that they all be
+ *           supported, and extensions can always be added to hardware drivers
+ *           after the base link libraries are released. These drivers are
+ *           dynamically loaded by libGL, so extensions not in the base
+ *           library must also be obtained dynamically.
+ *
+ *      3.6. To perform the dynamic query, libGL also must export an entry
+ *           point called
+ *
+ *           void (*glXGetProcAddressARB(const GLubyte *))(); 
+ *
+ *      The full specification of this function is available separately. It
+ *      takes the string name of a GL or GLX entry point and returns a pointer
+ *      to a function implementing that entry point. It is functionally
+ *      identical to the wglGetProcAddress query defined by the Windows OpenGL
+ *      library, except that the function pointers returned are context
+ *      independent, unlike the WGL query."
+ *
+ * From the EGL 1.4 spec:
+ *
+ *    "Client API function pointers returned by eglGetProcAddress are
+ *     independent of the display and the currently bound client API context,
+ *     and may be used by any client API context which supports the extension.
+ *
+ *     eglGetProcAddress may be queried for all of the following functions:
+ *
+ *     • All EGL and client API extension functions supported by the
+ *       implementation (whether those extensions are supported by the current
+ *       client API context or not). This includes any mandatory OpenGL ES
+ *       extensions.
+ *
+ *     eglGetProcAddress may not be queried for core (non-extension) functions
+ *     in EGL or client APIs 20 .
+ *
+ *     For functions that are queryable with eglGetProcAddress,
+ *     implementations may choose to also export those functions statically
+ *     from the object libraries im- plementing those functions. However,
+ *     portable clients cannot rely on this behavior.
+ *
+ * From the GLX 1.4 spec:
+ *
+ *     "glXGetProcAddress may be queried for all of the following functions:
+ *
+ *      • All GL and GLX extension functions supported by the implementation
+ *        (whether those extensions are supported by the current context or
+ *        not).
+ *
+ *      • All core (non-extension) functions in GL and GLX from version 1.0 up
+ *        to and including the versions of those specifications supported by
+ *        the implementation, as determined by glGetString(GL VERSION) and
+ *        glXQueryVersion queries."
+ */
+
+#include <assert.h>
+#include <stdlib.h>
+#ifdef _WIN32
+#include <windows.h>
+#else
+#include <dlfcn.h>
+#include <err.h>
+#include <pthread.h>
+#endif
+#include <string.h>
+#include <ctype.h>
+#include <stdio.h>
+
+#include "dispatch_common.h"
+
+#ifdef __APPLE__
+#define GLX_LIB "/opt/X11/lib/libGL.1.dylib"
+#else
+#define GLX_LIB "libGL.so.1"
+#endif
+
+struct api {
+#ifndef _WIN32
+    /**
+     * Locking for making sure we don't double-dlopen().
+     */
+    pthread_mutex_t mutex;
+#endif
+
+    /** dlopen() return value for libGL.so.1. */
+    void *glx_handle;
+
+    /**
+     * dlopen() return value for OS X's GL library.
+     *
+     * On linux, glx_handle is used instead.
+     */
+    void *gl_handle;
+
+    /** dlopen() return value for libEGL.so.1 */
+    void *egl_handle;
+
+    /** dlopen() return value for libGLESv1_CM.so.1 */
+    void *gles1_handle;
+
+    /** dlopen() return value for libGLESv2.so.2 */
+    void *gles2_handle;
+
+    /**
+     * This value gets incremented when any thread is in
+     * glBegin()/glEnd() called through epoxy.
+     *
+     * We're not guaranteed to be called through our wrapper, so the
+     * conservative paths also try to handle the failure cases they'll
+     * see if begin_count didn't reflect reality.  It's also a bit of
+     * a bug that the conservative paths might return success because
+     * some other thread was in epoxy glBegin/glEnd while our thread
+     * is trying to resolve, but given that it's basically just for
+     * informative error messages, we shouldn't need to care.
+     */
+    long begin_count;
+};
+
+static struct api api = {
+#ifndef _WIN32
+    .mutex = PTHREAD_MUTEX_INITIALIZER,
+#endif
+};
+
+static bool library_initialized;
+
+#if PLATFORM_HAS_EGL
+static EGLenum
+epoxy_egl_get_current_gl_context_api(void);
+#endif
+
+static void
+library_init(void) __attribute__((constructor));
+
+static void
+library_init(void)
+{
+    library_initialized = true;
+}
+
+static bool
+get_dlopen_handle(void **handle, const char *lib_name, bool exit_on_fail)
+{
+    if (*handle)
+        return true;
+
+    if (!library_initialized) {
+        fprintf(stderr,
+                "Attempting to dlopen() while in the dynamic linker.\n");
+        abort();
+    }
+
+#ifdef _WIN32
+    *handle = LoadLibraryA(lib_name);
+#else
+    pthread_mutex_lock(&api.mutex);
+    if (!*handle) {
+        *handle = dlopen(lib_name, RTLD_LAZY | RTLD_LOCAL);
+        if (!*handle) {
+            if (exit_on_fail) {
+                fprintf(stderr, "Couldn't open %s: %s\n", lib_name, dlerror());
+                exit(1);
+            } else {
+                (void)dlerror();
+            }
+        }
+    }
+    pthread_mutex_unlock(&api.mutex);
+#endif
+
+    return *handle != NULL;
+}
+
+static void *
+do_dlsym(void **handle, const char *lib_name, const char *name,
+         bool exit_on_fail)
+{
+    void *result;
+    const char *error = "";
+
+    if (!get_dlopen_handle(handle, lib_name, exit_on_fail))
+        return NULL;
+
+#ifdef _WIN32
+    result = GetProcAddress(*handle, name);
+#else
+    result = dlsym(*handle, name);
+    if (!result)
+        error = dlerror();
+#endif
+    if (!result && exit_on_fail) {
+        fprintf(stderr,"%s() not found in %s: %s\n", name, lib_name, error);
+        exit(1);
+    }
+
+    return result;
+}
+
+PUBLIC bool
+epoxy_is_desktop_gl(void)
+{
+    const char *es_prefix = "OpenGL ES";
+    const char *version;
+
+    if (api.begin_count)
+        return true;
+
+    version = (const char *)glGetString(GL_VERSION);
+
+    /* If we didn't get a version back, there are only two things that
+     * could have happened: either malloc failure (which basically
+     * doesn't exist), or we were called within a glBegin()/glEnd().
+     * Assume the second, which only exists for desktop GL.
+     */
+    if (!version)
+        return true;
+
+    return strncmp(es_prefix, version, strlen(es_prefix));
+}
+
+static int
+epoxy_internal_gl_version(int error_version)
+{
+    const char *version = (const char *)glGetString(GL_VERSION);
+    GLint major, minor;
+    int scanf_count;
+
+    if (!version)
+        return error_version;
+
+    /* skip to version number */
+    while (!isdigit(*version) && *version != '\0')
+        version++;
+
+    /* Interpret version number */
+    scanf_count = sscanf(version, "%i.%i", &major, &minor);
+    if (scanf_count != 2) {
+        fprintf(stderr, "Unable to interpret GL_VERSION string: %s\n",
+                version);
+        exit(1);
+    }
+    return 10 * major + minor;
+}
+
+PUBLIC int
+epoxy_gl_version(void)
+{
+    return epoxy_internal_gl_version(0);
+}
+
+PUBLIC int
+epoxy_conservative_gl_version(void)
+{
+    if (api.begin_count)
+        return 100;
+
+    return epoxy_internal_gl_version(100);
+}
+
+bool
+epoxy_extension_in_string(const char *extension_list, const char *ext)
+{
+    const char *ptr = extension_list;
+    int len = strlen(ext);
+
+    /* Make sure that don't just find an extension with our name as a prefix. */
+    while (true) {
+        ptr = strstr(ptr, ext);
+        if (!ptr)
+            return false;
+
+        if (ptr[len] == ' ' || ptr[len] == 0)
+            return true;
+        ptr += len;
+    }
+}
+
+static bool
+epoxy_internal_has_gl_extension(const char *ext, bool invalid_op_mode)
+{
+    if (epoxy_gl_version() < 30) {
+        const char *exts = (const char *)glGetString(GL_EXTENSIONS);
+        if (!exts)
+            return invalid_op_mode;
+        return epoxy_extension_in_string(exts, ext);
+    } else {
+        int num_extensions;
+
+        glGetIntegerv(GL_NUM_EXTENSIONS, &num_extensions);
+        if (num_extensions == 0)
+            return invalid_op_mode;
+
+        for (int i = 0; i < num_extensions; i++) {
+            const char *gl_ext = (const char *)glGetStringi(GL_EXTENSIONS, i);
+            if (strcmp(ext, gl_ext) == 0)
+                return true;
+        }
+
+        return false;
+    }
+}
+
+/**
+ * Tests whether the currently bound context is EGL or GLX, trying to
+ * avoid loading libraries unless necessary.
+ */
+static bool
+epoxy_current_context_is_glx(void)
+{
+#if !PLATFORM_HAS_GLX
+    return false;
+#else
+    /* If the application hasn't explicitly called some of our GLX
+     * or EGL code but has presumably set up a context on its own,
+     * then we need to figure out how to getprocaddress anyway.
+     *
+     * If there's a public GetProcAddress loaded in the
+     * application's namespace, then use that.
+     */
+    void *sym;
+
+    sym = dlsym(NULL, "glXGetCurrentContext");
+    if (sym) {
+        if (glXGetCurrentContext())
+            return true;
+    } else {
+        (void)dlerror();
+    }
+
+#if PLATFORM_HAS_EGL
+    sym = dlsym(NULL, "eglGetCurrentContext");
+    if (sym) {
+        if (epoxy_egl_get_current_gl_context_api() != EGL_NONE)
+            return true;
+    } else {
+        (void)dlerror();
+    }
+#endif /* PLATFORM_HAS_EGL */
+
+    /* OK, couldn't find anything in the app's address space.
+     * Presumably they dlopened with RTLD_LOCAL, which hides it
+     * from us.  Just go dlopen()ing likely libraries and try them.
+     */
+    sym = do_dlsym(&api.glx_handle, GLX_LIB, "glXGetCurrentContext", false);
+    if (sym && glXGetCurrentContext())
+        return true;
+
+#if PLATFORM_HAS_EGL
+    sym = do_dlsym(&api.egl_handle, "libEGL.so.1", "eglGetCurrentContext",
+                   false);
+    if (sym && epoxy_egl_get_current_gl_context_api() != EGL_NONE)
+        return false;
+#endif /* PLATFORM_HAS_EGL */
+
+    return false;
+#endif /* PLATFORM_HAS_GLX */
+}
+
+/**
+ * Returns true if the given GL extension is supported in the current context.
+ *
+ * Note that this function can't be called from within glBegin()/glEnd().
+ *
+ * \sa epoxy_has_egl_extension()
+ * \sa epoxy_has_glx_extension()
+ */
+PUBLIC bool
+epoxy_has_gl_extension(const char *ext)
+{
+    return epoxy_internal_has_gl_extension(ext, false);
+}
+
+bool
+epoxy_conservative_has_gl_extension(const char *ext)
+{
+    if (api.begin_count)
+        return true;
+
+    return epoxy_internal_has_gl_extension(ext, true);
+}
+
+void *
+epoxy_egl_dlsym(const char *name)
+{
+    return do_dlsym(&api.egl_handle, "libEGL.so.1", name, true);
+}
+
+void *
+epoxy_glx_dlsym(const char *name)
+{
+    return do_dlsym(&api.glx_handle, GLX_LIB, name, true);
+}
+
+void *
+epoxy_gl_dlsym(const char *name)
+{
+#ifdef _WIN32
+    return do_dlsym(&api.gl_handle, "OPENGL32", name, true);
+#elif defined(__APPLE__)
+    return do_dlsym(&api.gl_handle,
+                    "/System/Library/Frameworks/OpenGL.framework/Versions/Current/OpenGL",
+                    name, true);
+#else
+    /* There's no library for desktop GL support independent of GLX. */
+    return epoxy_glx_dlsym(name);
+#endif
+}
+
+void *
+epoxy_gles1_dlsym(const char *name)
+{
+    if (epoxy_current_context_is_glx()) {
+        return epoxy_get_proc_address(name);
+    } else {
+        return do_dlsym(&api.gles1_handle, "libGLESv1_CM.so.1", name, true);
+    }
+}
+
+void *
+epoxy_gles2_dlsym(const char *name)
+{
+    if (epoxy_current_context_is_glx()) {
+        return epoxy_get_proc_address(name);
+    } else {
+        return do_dlsym(&api.gles2_handle, "libGLESv2.so.2", name, true);
+    }
+}
+
+/**
+ * Does the appropriate dlsym() or eglGetProcAddress() for GLES3
+ * functions.
+ *
+ * Mesa interpreted GLES as intending that the GLES3 functions were
+ * available only through eglGetProcAddress() and not dlsym(), while
+ * ARM's Mali drivers interpreted GLES as intending that GLES3
+ * functions were available only through dlsym() and not
+ * eglGetProcAddress().  Thanks, Khronos.
+ */
+void *
+epoxy_gles3_dlsym(const char *name)
+{
+    if (epoxy_current_context_is_glx()) {
+        return epoxy_get_proc_address(name);
+    } else {
+        void *func = do_dlsym(&api.gles2_handle, "libGLESv2.so.2", name, false);
+
+        if (func)
+            return func;
+
+        return epoxy_get_proc_address(name);
+    }
+}
+
+/**
+ * Performs either the dlsym or glXGetProcAddress()-equivalent for
+ * core functions in desktop GL.
+ */
+void *
+epoxy_get_core_proc_address(const char *name, int core_version)
+{
+#ifdef _WIN32
+    int core_symbol_support = 10;
+#else
+    int core_symbol_support = 12;
+#endif
+
+    if (core_version <= core_symbol_support) {
+        return epoxy_gl_dlsym(name);
+    } else {
+        return epoxy_get_proc_address(name);
+    }
+}
+
+#if PLATFORM_HAS_EGL
+static EGLenum
+epoxy_egl_get_current_gl_context_api(void)
+{
+    EGLenum save_api = eglQueryAPI();
+    EGLContext ctx;
+
+    if (eglBindAPI(EGL_OPENGL_API)) {
+        ctx = eglGetCurrentContext();
+        if (ctx) {
+            eglBindAPI(save_api);
+            return EGL_OPENGL_API;
+        }
+    } else {
+        (void)eglGetError();
+    }
+
+    if (eglBindAPI(EGL_OPENGL_ES_API)) {
+        ctx = eglGetCurrentContext();
+        eglBindAPI(save_api);
+        if (ctx) {
+            eglBindAPI(save_api);
+            return EGL_OPENGL_ES_API;
+        }
+    } else {
+        (void)eglGetError();
+    }
+
+    return EGL_NONE;
+}
+#endif /* PLATFORM_HAS_EGL */
+
+/**
+ * Performs the dlsym() for the core GL 1.0 functions that we use for
+ * determining version and extension support for deciding on dlsym
+ * versus glXGetProcAddress() for all other functions.
+ *
+ * This needs to succeed on implementations without GLX (since
+ * glGetString() and glGetIntegerv() are both in GLES1/2 as well, and
+ * at call time we don't know for sure what API they're trying to use
+ * without inspecting contexts ourselves).
+ */
+void *
+epoxy_get_bootstrap_proc_address(const char *name)
+{
+    /* If we already have a library that links to libglapi loaded,
+     * use that.
+     */
+#if PLATFORM_HAS_GLX
+    if (api.glx_handle && glXGetCurrentContext())
+        return epoxy_gl_dlsym(name);
+#endif
+
+    /* If epoxy hasn't loaded any API-specific library yet, try to
+     * figure out what API the context is using and use that library,
+     * since future calls will also use that API (this prevents a
+     * non-X11 ES2 context from loading a bunch of X11 junk).
+     */
+#if PLATFORM_HAS_EGL
+    get_dlopen_handle(&api.egl_handle, "libEGL.so.1", false);
+    if (api.egl_handle) {
+        switch (epoxy_egl_get_current_gl_context_api()) {
+        case EGL_OPENGL_API:
+            return epoxy_gl_dlsym(name);
+        case EGL_OPENGL_ES_API:
+            /* We can't resolve the GL version, because
+             * epoxy_glGetString() is one of the two things calling
+             * us.  Try the GLES2 implementation first, and fall back
+             * to GLES1 otherwise.
+             */
+            get_dlopen_handle(&api.gles2_handle, "libGLESv2.so.2", false);
+            if (api.gles2_handle)
+                return epoxy_gles2_dlsym(name);
+            else
+                return epoxy_gles1_dlsym(name);
+        }
+    }
+#endif /* PLATFORM_HAS_EGL */
+
+    /* Fall back to GLX */
+    return epoxy_gl_dlsym(name);
+}
+
+void *
+epoxy_get_proc_address(const char *name)
+{
+#ifdef _WIN32
+    return wglGetProcAddress(name);
+#elif defined(__APPLE__)
+    return epoxy_gl_dlsym(name);
+#else
+    if (epoxy_current_context_is_glx()) {
+        return glXGetProcAddressARB((const GLubyte *)name);
+    } else {
+#if PLATFORM_HAS_EGL
+        GLenum egl_api = epoxy_egl_get_current_gl_context_api();
+
+        switch (egl_api) {
+        case EGL_OPENGL_API:
+        case EGL_OPENGL_ES_API:
+            return eglGetProcAddress(name);
+        case EGL_NONE:
+            break;
+        }
+#endif
+    }
+    errx(1, "Couldn't find current GLX or EGL context.\n");
+#endif
+}
+
+void
+epoxy_print_failure_reasons(const char *name,
+                            const char **provider_names,
+                            const int *providers)
+{
+    int i;
+
+    fprintf(stderr, "No provider of %s found.  Requires one of:\n", name);
+
+    for (i = 0; providers[i] != 0; i++)
+        fprintf(stderr, "    %s\n",
+                provider_names[providers[i]]);
+
+    if (providers[0] == 0) {
+        fprintf(stderr, "    No known providers.  This is likely a bug "
+                "in libepoxy code generation\n");
+    }
+}
+
+WRAPPER_VISIBILITY void
+WRAPPER(epoxy_glBegin)(GLenum primtype)
+{
+#ifdef _WIN32
+    InterlockedIncrement(&api.begin_count);
+#else
+    pthread_mutex_lock(&api.mutex);
+    api.begin_count++;
+    pthread_mutex_unlock(&api.mutex);
+#endif
+
+    epoxy_glBegin_unwrapped(primtype);
+}
+
+WRAPPER_VISIBILITY void
+WRAPPER(epoxy_glEnd)(void)
+{
+    epoxy_glEnd_unwrapped();
+
+#ifdef _WIN32
+    InterlockedDecrement(&api.begin_count);
+#else
+    pthread_mutex_lock(&api.mutex);
+    api.begin_count--;
+    pthread_mutex_unlock(&api.mutex);
+#endif
+}
+
+PUBLIC PFNGLBEGINPROC epoxy_glBegin = epoxy_glBegin_wrapped;
+PUBLIC PFNGLENDPROC epoxy_glEnd = epoxy_glEnd_wrapped;