1 //===-- DynamicLibrary.cpp - Runtime link/load libraries --------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This header file implements the operating system DynamicLibrary concept.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/System/DynamicLibrary.h"
15 #include "llvm/Config/config.h"
19 // Collection of symbol name/value pairs to be searched prior to any libraries.
20 static std::map<std::string, void *> g_symbols;
22 void llvm::sys::DynamicLibrary::AddSymbol(const char* symbolName,
24 g_symbols[symbolName] = symbolValue;
27 // It is not possible to use ltdl.c on VC++ builds as the terms of its LGPL
28 // license and special exception would cause all of LLVM to be placed under
29 // the LGPL. This is because the exception applies only when libtool is
30 // used, and obviously libtool is not used with Visual Studio. An entirely
31 // separate implementation is provided in win32/DynamicLibrary.cpp.
35 #include "Win32/DynamicLibrary.inc"
43 using namespace llvm::sys;
45 //===----------------------------------------------------------------------===//
46 //=== WARNING: Implementation here must contain only TRULY operating system
47 //=== independent code.
48 //===----------------------------------------------------------------------===//
50 //static std::vector<lt_dlhandle> OpenedHandles;
51 static std::vector<void *> OpenedHandles;
53 DynamicLibrary::DynamicLibrary() : handle(0) {}
55 DynamicLibrary::~DynamicLibrary() {
56 while(!OpenedHandles.empty()) {
57 void *H = OpenedHandles.back(); OpenedHandles.pop_back();
62 bool DynamicLibrary::LoadLibraryPermanently(const char *Filename,
63 std::string *ErrMsg) {
64 void *H = dlopen(Filename, RTLD_LAZY);
66 ErrMsg = new std::string(dlerror());
69 OpenedHandles.push_back(H);
73 void* DynamicLibrary::SearchForAddressOfSymbol(const char* symbolName) {
74 // check_ltdl_initialization();
76 // First check symbols added via AddSymbol().
77 std::map<std::string, void *>::iterator I = g_symbols.find(symbolName);
78 if (I != g_symbols.end())
81 // Now search the libraries.
82 for (std::vector<void *>::iterator I = OpenedHandles.begin(),
83 E = OpenedHandles.end(); I != E; ++I) {
84 //lt_ptr ptr = lt_dlsym(*I, symbolName);
85 void *ptr = dlsym(*I, symbolName);
90 #define EXPLICIT_SYMBOL(SYM) \
91 extern void *SYM; if (!strcmp(symbolName, #SYM)) return &SYM
93 // If this is darwin, it has some funky issues, try to solve them here. Some
94 // important symbols are marked 'private external' which doesn't allow
95 // SearchForAddressOfSymbol to find them. As such, we special case them here,
96 // there is only a small handful of them.
100 EXPLICIT_SYMBOL(__ashldi3);
101 EXPLICIT_SYMBOL(__ashrdi3);
102 EXPLICIT_SYMBOL(__cmpdi2);
103 EXPLICIT_SYMBOL(__divdi3);
104 EXPLICIT_SYMBOL(__eprintf);
105 EXPLICIT_SYMBOL(__fixdfdi);
106 EXPLICIT_SYMBOL(__fixsfdi);
107 EXPLICIT_SYMBOL(__fixunsdfdi);
108 EXPLICIT_SYMBOL(__fixunssfdi);
109 EXPLICIT_SYMBOL(__floatdidf);
110 EXPLICIT_SYMBOL(__floatdisf);
111 EXPLICIT_SYMBOL(__lshrdi3);
112 EXPLICIT_SYMBOL(__moddi3);
113 EXPLICIT_SYMBOL(__udivdi3);
114 EXPLICIT_SYMBOL(__umoddi3);
120 EXPLICIT_SYMBOL(_alloca);
124 #undef EXPLICIT_SYMBOL
126 // This macro returns the address of a well-known, explicit symbol
127 #define EXPLICIT_SYMBOL(SYM) \
128 if (!strcmp(symbolName, #SYM)) return &SYM
130 // On linux we have a weird situation. The stderr/out/in symbols are both
131 // macros and global variables because of standards requirements. So, we
132 // boldly use the EXPLICIT_SYMBOL macro without checking for a #define first.
133 #if defined(__linux__)
135 EXPLICIT_SYMBOL(stderr);
136 EXPLICIT_SYMBOL(stdout);
137 EXPLICIT_SYMBOL(stdin);
140 // For everything else, we want to check to make sure the symbol isn't defined
141 // as a macro before using EXPLICIT_SYMBOL.
144 EXPLICIT_SYMBOL(stdin);
147 EXPLICIT_SYMBOL(stdout);
150 EXPLICIT_SYMBOL(stderr);
154 #undef EXPLICIT_SYMBOL
159 void *DynamicLibrary::GetAddressOfSymbol(const char *symbolName) {
160 assert(handle != 0 && "Invalid DynamicLibrary handle");
161 return dlsym(handle, symbolName);
164 #endif // LLVM_ON_WIN32
166 DEFINING_FILE_FOR(SystemDynamicLibrary)