1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
|
//===-- DynamicLibrary.cpp - Runtime link/load libraries --------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This header file implements the operating system DynamicLibrary concept.
//
// FIXME: This file leaks the ExplicitSymbols and OpenedHandles vector, and is
// not thread safe!
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/DynamicLibrary.h"
#include "llvm/Support/Mutex.h"
#include "llvm/Config/config.h"
#include <cstdio>
#include <cstring>
#include <map>
#include <vector>
// Collection of symbol name/value pairs to be searched prior to any libraries.
static std::map<std::string, void*> *ExplicitSymbols = 0;
namespace {
struct ExplicitSymbolsDeleter {
~ExplicitSymbolsDeleter() {
if (ExplicitSymbols)
delete ExplicitSymbols;
}
};
}
static ExplicitSymbolsDeleter Dummy;
void llvm::sys::DynamicLibrary::AddSymbol(const char* symbolName,
void *symbolValue) {
if (ExplicitSymbols == 0)
ExplicitSymbols = new std::map<std::string, void*>();
(*ExplicitSymbols)[symbolName] = symbolValue;
}
#ifdef LLVM_ON_WIN32
#include "Windows/DynamicLibrary.inc"
#else
#if HAVE_DLFCN_H
#include <dlfcn.h>
using namespace llvm;
using namespace llvm::sys;
//===----------------------------------------------------------------------===//
//=== WARNING: Implementation here must contain only TRULY operating system
//=== independent code.
//===----------------------------------------------------------------------===//
static SmartMutex<true>* HandlesMutex;
static std::vector<void *> *OpenedHandles = 0;
static bool InitializeMutex() {
HandlesMutex = new SmartMutex<true>;
return HandlesMutex != 0;
}
static bool EnsureMutexInitialized() {
static bool result = InitializeMutex();
return result;
}
bool DynamicLibrary::LoadLibraryPermanently(const char *Filename,
std::string *ErrMsg) {
void *H = dlopen(Filename, RTLD_LAZY|RTLD_GLOBAL);
if (H == 0) {
if (ErrMsg) *ErrMsg = dlerror();
return true;
}
#ifdef __CYGWIN__
// Cygwin searches symbols only in the main
// with the handle of dlopen(NULL, RTLD_GLOBAL).
if (Filename == NULL)
H = RTLD_DEFAULT;
#endif
EnsureMutexInitialized();
SmartScopedLock<true> Lock(*HandlesMutex);
if (OpenedHandles == 0)
OpenedHandles = new std::vector<void *>();
OpenedHandles->push_back(H);
return false;
}
#else
using namespace llvm;
using namespace llvm::sys;
bool DynamicLibrary::LoadLibraryPermanently(const char *Filename,
std::string *ErrMsg) {
if (ErrMsg) *ErrMsg = "dlopen() not supported on this platform";
return true;
}
#endif
namespace llvm {
void *SearchForAddressOfSpecialSymbol(const char* symbolName);
}
void* DynamicLibrary::SearchForAddressOfSymbol(const char* symbolName) {
// First check symbols added via AddSymbol().
if (ExplicitSymbols) {
std::map<std::string, void *>::iterator I =
ExplicitSymbols->find(symbolName);
std::map<std::string, void *>::iterator E = ExplicitSymbols->end();
if (I != E)
return I->second;
}
#if HAVE_DLFCN_H
// Now search the libraries.
EnsureMutexInitialized();
SmartScopedLock<true> Lock(*HandlesMutex);
if (OpenedHandles) {
for (std::vector<void *>::iterator I = OpenedHandles->begin(),
E = OpenedHandles->end(); I != E; ++I) {
//lt_ptr ptr = lt_dlsym(*I, symbolName);
void *ptr = dlsym(*I, symbolName);
if (ptr) {
return ptr;
}
}
}
#endif
if (void *Result = llvm::SearchForAddressOfSpecialSymbol(symbolName))
return Result;
// This macro returns the address of a well-known, explicit symbol
#define EXPLICIT_SYMBOL(SYM) \
if (!strcmp(symbolName, #SYM)) return &SYM
// On linux we have a weird situation. The stderr/out/in symbols are both
// macros and global variables because of standards requirements. So, we
// boldly use the EXPLICIT_SYMBOL macro without checking for a #define first.
#if defined(__linux__)
{
EXPLICIT_SYMBOL(stderr);
EXPLICIT_SYMBOL(stdout);
EXPLICIT_SYMBOL(stdin);
}
#else
// For everything else, we want to check to make sure the symbol isn't defined
// as a macro before using EXPLICIT_SYMBOL.
{
#ifndef stdin
EXPLICIT_SYMBOL(stdin);
#endif
#ifndef stdout
EXPLICIT_SYMBOL(stdout);
#endif
#ifndef stderr
EXPLICIT_SYMBOL(stderr);
#endif
}
#endif
#undef EXPLICIT_SYMBOL
return 0;
}
#endif // LLVM_ON_WIN32
|
