Initial work

external/android-emugl/shared/emugl/common/shared_library.cpp

@@ -0,0 +1,169 @@
+// Copyright (C) 2014 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 "emugl/common/shared_library.h"
+
+#include <stddef.h>
+#include <string.h>
+#include <stdio.h>
+
+#ifndef _WIN32
+#include <dlfcn.h>
+#include <stdlib.h>
+#endif
+
+namespace emugl {
+
+// static
+SharedLibrary* SharedLibrary::open(const char* libraryName) {
+    char error[1];
+    return open(libraryName, error, sizeof(error));
+}
+
+#ifdef _WIN32
+
+// static
+SharedLibrary* SharedLibrary::open(const char* libraryName,
+                                   char* error,
+                                   size_t errorSize) {
+    HMODULE lib = LoadLibrary(libraryName);
+    if (lib) {
+        return new SharedLibrary(lib);
+    }
+
+    if (errorSize == 0) {
+        return NULL;
+    }
+
+    // Convert error into human-readable message.
+    DWORD errorCode = ::GetLastError();
+    LPSTR message = NULL;
+    size_t messageLen = FormatMessageA(
+            FORMAT_MESSAGE_ALLOCATE_BUFFER |
+            FORMAT_MESSAGE_FROM_SYSTEM |
+            FORMAT_MESSAGE_IGNORE_INSERTS,
+            NULL,
+            errorCode,
+            MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+            (LPSTR) &message,
+            0,
+            NULL);
+
+    int ret = snprintf(error, errorSize, "%.*s", (int)messageLen, message);
+    if (ret < 0 || ret == static_cast<int>(errorSize)) {
+        // snprintf() on Windows doesn't behave as expected by C99,
+        // this path is to ensure that the result is always properly
+        // zero-terminated.
+        ret = static_cast<int>(errorSize - 1);
+        error[ret] = '\0';
+    }
+    // Remove any trailing \r\n added by FormatMessage
+    if (ret > 0 && error[ret - 1] == '\n') {
+        error[--ret] = '\0';
+    }
+    if (ret > 0 && error[ret - 1] == '\r') {
+        error[--ret] = '\0';
+    }
+    return NULL;
+}
+
+SharedLibrary::SharedLibrary(HandleType lib) : mLib(lib) {}
+
+SharedLibrary::~SharedLibrary() {
+    if (mLib) {
+        FreeLibrary(mLib);
+    }
+}
+
+SharedLibrary::FunctionPtr SharedLibrary::findSymbol(
+        const char* symbolName) const {
+    if (!mLib || !symbolName) {
+        return NULL;
+    }
+    return reinterpret_cast<FunctionPtr>(
+                GetProcAddress(mLib, symbolName));
+}
+
+#else // !_WIN32
+
+// static
+SharedLibrary* SharedLibrary::open(const char* libraryName,
+                                   char* error,
+                                   size_t errorSize) {
+    const char* libPath = libraryName;
+    char* path = NULL;
+
+    const char* libBaseName = strrchr(libraryName, '/');
+    if (!libBaseName) {
+        libBaseName = libraryName;
+    }
+
+    if (!strchr(libBaseName, '.')) {
+        // There is no extension in this library name, so append one.
+#ifdef __APPLE__
+        static const char kDllExtension[] = ".dylib";
+#else
+        static const char kDllExtension[] = ".so";
+#endif
+        size_t pathLen = strlen(libraryName) + sizeof(kDllExtension);
+        path = static_cast<char*>(malloc(pathLen));
+        snprintf(path, pathLen, "%s%s", libraryName, kDllExtension);
+        libPath = path;
+    }
+
+    dlerror();  // clear error.
+
+#ifdef __APPLE__
+    // On OSX, some libraries don't include an extension (notably OpenGL)
+    // On OSX we try to open |libraryName| first.  If that doesn't exist,
+    // we try |libraryName|.dylib
+    void* lib = dlopen(libraryName, RTLD_NOW);
+    if (lib == NULL) {
+        lib = dlopen(libPath, RTLD_NOW);
+    }
+#else
+    void* lib = dlopen(libPath, RTLD_NOW);
+#endif
+
+    if (path) {
+        free(path);
+    }
+
+    if (lib) {
+        return new SharedLibrary(lib);
+    }
+
+    snprintf(error, errorSize, "%s", dlerror());
+    return NULL;
+}
+
+SharedLibrary::SharedLibrary(HandleType lib) : mLib(lib) {}
+
+SharedLibrary::~SharedLibrary() {
+    if (mLib) {
+        dlclose(mLib);
+    }
+}
+
+SharedLibrary::FunctionPtr SharedLibrary::findSymbol(
+        const char* symbolName) const {
+    if (!mLib || !symbolName) {
+        return NULL;
+    }
+    return reinterpret_cast<FunctionPtr>(dlsym(mLib, symbolName));
+}
+
+#endif  // !_WIN32
+
+}  // namespace emugl