1/*
2 * Copyright 2012, The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *     http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "bcc/ExecutionEngine/SymbolResolvers.h"
18
19#if !defined(_WIN32)  /* TODO create a HAVE_DLFCN_H */
20#include <dlfcn.h>
21#else
22/* TODO hack: definitions from bionic/libc/include/dlfcn.h */
23void* dlopen(const char*  filename, int flag) {
24  return NULL;
25}
26
27int dlclose(void*  handle) {
28  return -1;
29}
30
31const char* dlerror(void) {
32  return "Unspecified error!";
33}
34
35void* dlsym(void*  handle, const char*  symbol) {
36  return NULL;
37}
38
39#define RTLD_NOW    0
40#define RTLD_LAZY   1
41#define RTLD_LOCAL  0
42#define RTLD_GLOBAL 2
43#define RTLD_DEFAULT  ((void*) 0xffffffff)
44#define RTLD_NEXT     ((void*) 0xfffffffe)
45#endif
46
47#include <cassert>
48#include <cstdio>
49#include <new>
50
51using namespace bcc;
52
53//===----------------------------------------------------------------------===//
54// DyldSymbolResolver
55//===----------------------------------------------------------------------===//
56DyldSymbolResolver::DyldSymbolResolver(const char *pFileName,
57                                       bool pLazyBinding) : mError(NULL) {
58  int flags = (pLazyBinding) ? RTLD_LAZY : RTLD_NOW;
59
60  // Make the symbol within the given library to be local such that it won't
61  // be available for symbol resolution of subsequently loaded libraries.
62  flags |= RTLD_LOCAL;
63
64  mHandle = ::dlopen(pFileName, flags);
65  if (mHandle == NULL) {
66    const char *err = ::dlerror();
67
68#define DYLD_ERROR_MSG_PATTERN  "Failed to load %s! (%s)"
69    size_t error_length = ::strlen(DYLD_ERROR_MSG_PATTERN) +
70                          ::strlen(pFileName) + 1;
71    if (err != NULL) {
72      error_length += ::strlen(err);
73    }
74
75    mError = new (std::nothrow) char [error_length];
76    if (mError != NULL) {
77      ::snprintf(mError, error_length, DYLD_ERROR_MSG_PATTERN, pFileName,
78                 ((err != NULL) ? err : ""));
79    }
80  }
81#undef DYLD_ERROR_MSG_PATTERN
82}
83
84void *DyldSymbolResolver::getAddress(const char *pName) {
85  assert((mHandle != NULL) && "Invalid DyldSymbolResolver!");
86  return ::dlsym(mHandle, pName);
87}
88
89DyldSymbolResolver::~DyldSymbolResolver() {
90  if (mHandle != NULL) {
91    ::dlclose(mHandle);
92    mHandle = NULL;
93  }
94  delete [] mError;
95}
96