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 */
dlopen(const char * filename,int flag)23 void* dlopen(const char* filename, int flag) {
24 return NULL;
25 }
26
dlclose(void * handle)27 int dlclose(void* handle) {
28 return -1;
29 }
30
dlerror(void)31 const char* dlerror(void) {
32 return "Unspecified error!";
33 }
34
dlsym(void * handle,const char * symbol)35 void* 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
51 using namespace bcc;
52
53 //===----------------------------------------------------------------------===//
54 // DyldSymbolResolver
55 //===----------------------------------------------------------------------===//
DyldSymbolResolver(const char * pFileName,bool pLazyBinding)56 DyldSymbolResolver::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
getAddress(const char * pName)84 void *DyldSymbolResolver::getAddress(const char *pName) {
85 assert((mHandle != NULL) && "Invalid DyldSymbolResolver!");
86 return ::dlsym(mHandle, pName);
87 }
88
~DyldSymbolResolver()89 DyldSymbolResolver::~DyldSymbolResolver() {
90 if (mHandle != NULL) {
91 ::dlclose(mHandle);
92 mHandle = NULL;
93 }
94 delete [] mError;
95 }
96