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 file implements the operating system DynamicLibrary concept.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/Support/DynamicLibrary.h"
15 #include "llvm-c/Support.h"
16 #include "llvm/ADT/DenseSet.h"
17 #include "llvm/ADT/StringMap.h"
18 #include "llvm/Config/config.h"
19 #include "llvm/Support/ManagedStatic.h"
20 #include "llvm/Support/Mutex.h"
24 // Collection of symbol name/value pairs to be searched prior to any libraries.
25 static llvm::ManagedStatic<llvm::StringMap<void *> > ExplicitSymbols;
26 static llvm::ManagedStatic<llvm::sys::SmartMutex<true> > SymbolsMutex;
28 void llvm::sys::DynamicLibrary::AddSymbol(StringRef symbolName,
30 SmartScopedLock<true> lock(*SymbolsMutex);
31 (*ExplicitSymbols)[symbolName] = symbolValue;
34 char llvm::sys::DynamicLibrary::Invalid = 0;
38 #include "Windows/DynamicLibrary.inc"
42 #if defined(HAVE_DLFCN_H) && defined(HAVE_DLOPEN)
45 using namespace llvm::sys;
47 //===----------------------------------------------------------------------===//
48 //=== WARNING: Implementation here must contain only TRULY operating system
49 //=== independent code.
50 //===----------------------------------------------------------------------===//
52 static llvm::ManagedStatic<DenseSet<void *> > OpenedHandles;
54 DynamicLibrary DynamicLibrary::getPermanentLibrary(const char *filename,
55 std::string *errMsg) {
56 SmartScopedLock<true> lock(*SymbolsMutex);
58 void *handle = dlopen(filename, RTLD_LAZY|RTLD_GLOBAL);
60 if (errMsg) *errMsg = dlerror();
61 return DynamicLibrary();
65 // Cygwin searches symbols only in the main
66 // with the handle of dlopen(NULL, RTLD_GLOBAL).
68 handle = RTLD_DEFAULT;
71 // If we've already loaded this library, dlclose() the handle in order to
72 // keep the internal refcount at +1.
73 if (!OpenedHandles->insert(handle).second)
76 return DynamicLibrary(handle);
79 DynamicLibrary DynamicLibrary::addPermanentLibrary(void *handle,
80 std::string *errMsg) {
81 SmartScopedLock<true> lock(*SymbolsMutex);
82 // If we've already loaded this library, tell the caller.
83 if (!OpenedHandles->insert(handle).second) {
84 if (errMsg) *errMsg = "Library already loaded";
85 return DynamicLibrary();
88 return DynamicLibrary(handle);
91 void *DynamicLibrary::getAddressOfSymbol(const char *symbolName) {
94 return dlsym(Data, symbolName);
100 using namespace llvm::sys;
102 DynamicLibrary DynamicLibrary::getPermanentLibrary(const char *filename,
103 std::string *errMsg) {
104 if (errMsg) *errMsg = "dlopen() not supported on this platform";
105 return DynamicLibrary();
108 void *DynamicLibrary::getAddressOfSymbol(const char *symbolName) {
115 void *SearchForAddressOfSpecialSymbol(const char* symbolName);
118 void* DynamicLibrary::SearchForAddressOfSymbol(const char *symbolName) {
119 SmartScopedLock<true> Lock(*SymbolsMutex);
121 // First check symbols added via AddSymbol().
122 if (ExplicitSymbols.isConstructed()) {
123 StringMap<void *>::iterator i = ExplicitSymbols->find(symbolName);
125 if (i != ExplicitSymbols->end())
129 #if defined(HAVE_DLFCN_H) && defined(HAVE_DLOPEN)
130 // Now search the libraries.
131 if (OpenedHandles.isConstructed()) {
132 for (DenseSet<void *>::iterator I = OpenedHandles->begin(),
133 E = OpenedHandles->end(); I != E; ++I) {
134 //lt_ptr ptr = lt_dlsym(*I, symbolName);
135 void *ptr = dlsym(*I, symbolName);
143 if (void *Result = llvm::SearchForAddressOfSpecialSymbol(symbolName))
146 // This macro returns the address of a well-known, explicit symbol
147 #define EXPLICIT_SYMBOL(SYM) \
148 if (!strcmp(symbolName, #SYM)) return &SYM
150 // On linux we have a weird situation. The stderr/out/in symbols are both
151 // macros and global variables because of standards requirements. So, we
152 // boldly use the EXPLICIT_SYMBOL macro without checking for a #define first.
153 #if defined(__linux__) and !defined(__ANDROID__)
155 EXPLICIT_SYMBOL(stderr);
156 EXPLICIT_SYMBOL(stdout);
157 EXPLICIT_SYMBOL(stdin);
160 // For everything else, we want to check to make sure the symbol isn't defined
161 // as a macro before using EXPLICIT_SYMBOL.
164 EXPLICIT_SYMBOL(stdin);
167 EXPLICIT_SYMBOL(stdout);
170 EXPLICIT_SYMBOL(stderr);
174 #undef EXPLICIT_SYMBOL
179 #endif // LLVM_ON_WIN32
181 //===----------------------------------------------------------------------===//
183 //===----------------------------------------------------------------------===//
185 LLVMBool LLVMLoadLibraryPermanently(const char* Filename) {
186 return llvm::sys::DynamicLibrary::LoadLibraryPermanently(Filename);
189 void *LLVMSearchForAddressOfSymbol(const char *symbolName) {
190 return llvm::sys::DynamicLibrary::SearchForAddressOfSymbol(symbolName);
193 void LLVMAddSymbol(const char *symbolName, void *symbolValue) {
194 return llvm::sys::DynamicLibrary::AddSymbol(symbolName, symbolValue);