aosp12/libnativehelper/DlHelp.c

83 lines
2.2 KiB
C

/*
* Copyright (C) 2020 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 "DlHelp.h"
#include <stdbool.h>
#ifdef WIN32_LEAN_AND_MEAN
#include <stdio.h>
#include <windows.h>
#else
#include <dlfcn.h>
#endif
DlLibrary DlOpenLibrary(const char* filename) {
#ifdef _WIN32
return LoadLibrary(filename);
#else
// Load with RTLD_NODELETE in order to ensure that libart.so is not unmapped when it is closed.
// This is due to the fact that it is possible that some threads might have yet to finish
// exiting even after JNI_DeleteJavaVM returns, which can lead to segfaults if the library is
// unloaded.
return dlopen(filename, RTLD_NOW | RTLD_NODELETE);
#endif
}
bool DlCloseLibrary(DlLibrary library) {
#ifdef _WIN32
return (FreeLibrary(library) == TRUE);
#else
return (dlclose(library) == 0);
#endif
}
DlSymbol DlGetSymbol(DlLibrary handle, const char* symbol) {
#ifdef _WIN32
return (DlSymbol) GetProcAddress(handle, symbol);
#else
return dlsym(handle, symbol);
#endif
}
const char* DlGetError() {
#ifdef _WIN32
static char buffer[256];
DWORD cause = GetLastError();
DWORD flags = FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS;
DWORD length = FormatMessageA(flags, NULL, cause, 0, buffer, sizeof(buffer), NULL);
if (length == 0) {
snprintf(buffer, sizeof(buffer),
"Error %lu while retrieving message for error %lu",
GetLastError(), cause);
length = strlen(buffer);
}
// Trim trailing whitespace.
for (DWORD i = length - 1; i > 0; --i) {
if (!isspace(buffer[i])) {
break;
}
buffer[i] = '\0';
}
return buffer;
#else
return dlerror();
#endif
}